Articles : Journal of Carcinogenesis as on January 27, 2012)

Comparative metabolism of benzo[a]pyrene by human keratinocytes infected with high-risk human papillomavirus types 16 and 18 as episomal or integrated genomes

Neil Trushin — Fri,27 Jan 2012

Neil Trushin, Samina Alam, Karam El-Bayoumy, Jacek Krzeminski, Shantu G Amin, Jenny Gullett, Craig Meyers, Bogdan Prokopczyk

Journal of Carcinogenesis 2012 11(1):1-1

Background: Infection with human papillomavirus (HPV) is a critical factor in the development of cervical cancer. Smoking is an additional risk factor. Tobacco smoke carcinogens, such as benzo[a]pyrene (B[a]P), and their cytochrome P450-related metabolites are present in significantly higher levels in the cervical mucus of women smokers than in nonsmokers. We determined the metabolism and P450 expression of B[a]P-treated human keratinocytes infected with HPV-16 or -18. Materials and Methods: Monolayer cultures of uninfected primary human foreskin keratinocytes, human vaginal and cervical keratinocytes carrying episomal genomes of HPV-16 and -18, respectively, and invasive cervical carcinoma cell lines carrying either HPV-16 or -18 genomes integrated into the host DNA, were incubated with 0.1 μM [3H]B[a]P. The resulting oxidative metabolites were analyzed and quantified by radioflow high-performance liquid chromatography. Additionally, all cell lines were incubated with unlabeled 0.1 μM B[a]P for Western blot analysis of cytochrome P450 1A1 and 1B1. Results: Significant enhancement in levels of both detoxification and activation metabolites was found in incubations with all types of HPV-infected cells compared with control incubations (P < 0.05). The highest capacity to metabolize B[a]P was observed with cells containing integrated HPV-18 genomes. Induction of cytochrome 1B1 was observed in HPV-16 and -18 integrated, and in HPV-16 episomal cell types. Conclusions: Both viral genotype and genomic status in the host cell affect B[a]P metabolism and cytochrome P450 1B1 expression. An increase of DNA-damaging metabolites might result from exposure of HPV-infected women to cigarette smoke carcinogens.

Role of chemokine receptor CXCR2 expression in mammary tumor growth, angiogenesis and metastasis

Kalyan C Nannuru — Sat,31 Dec 2011

Kalyan C Nannuru, Bhawna Sharma, Michelle L Varney, Rakesh K Singh

Journal of Carcinogenesis 2011 10(1):40-40

Background: Chemokines and their receptors have long been known to regulate metastasis in various cancers. Previous studies have shown that CXCR2 expression is upregulated in malignant breast cancer tissues but not in benign ductal epithelial samples. The functional role of CXCR2 in the metastatic phenotype of breast cancer still remains unclear. We hypothesize that the chemokine receptor, CXCR2, mediates tumor cell invasion and migration and promotes metastasis in breast cancer. The objective of this study is to investigate the potential role of CXCR2 in the metastatic phenotype of mouse mammary tumor cells. Materials and Methods: We evaluated the functional role of CXCR2 in breast cancer by stably downregulating the expression of CXCR2 in metastatic mammary tumor cell lines Cl66 and 4T1, using short hairpin RNA (shRNA). The effects of CXCR2 downregulation on tumor growth, invasion and metastatic potential were analyzed in vitro and in vivo. Results: We demonstrated knock down of CXCR2 in Cl66 and 4T1 cells (Cl66-shCXCR2 and 4T1-shCXCR2) cells by reverse transcriptase polymerase chain reaction (RT-PCR) at the transcriptional level and by immunohistochemistry at the protein level. We did not observe a significant difference in in vitro cell proliferation between vector control and CXCR2 knock-down Cl66 or 4T1 cells. Next, we examined the invasive potential of Cl66-shCXCR2 cells by in vitro Matrigel invasion assay. We observed a significantly lower number (52 ± 5) of Cl66-shCXCR2 cells invading through Matrigel compared to control cells (Cl66-control) (182 ± 3) (P < 0.05). We analyzed the in vivo metastatic potential of Cl66-shCXCR2 using a spontaneous metastasis model by orthotopically implanting cells into the mammary fat pad of female BALB/c mice. Animals were sacrificed 12 weeks post tumor implantation and tissue samples were analyzed for metastatic nodules. CXCR2 downregulation significantly inhibited tumor cell metastasis. All the mice (n = 10) implanted with control Cl66 cells spontaneously developed lung metastasis, whereas a significantly lower number of mice (40%) implanted with Cl66-shCXCR2 cells exhibited lung metastases. Conclusions: Together, these results suggest that CXCR2 may play a critical role in breast cancer invasion and metastasis.

A block in lineage differentiation of immortal human mammary stem / progenitor cells by ectopically-expressed oncogenes

Xiangshan Zhao — Sat,31 Dec 2011

Xiangshan Zhao, Gautam K Malhotra, Hamid Band, Vimla Band

Journal of Carcinogenesis 2011 10(1):39-39

Introduction: Emerging evidence suggests a direct role of cancer stem cells (CSCs) in the development of breast cancer. In vitro cellular models that recapitulate properties of CSCs are therefore highly desirable. We have previously shown that normal human mammary epithelial cells (hMECs) immortalized with human telomerase reverse transcriptase (hTERT) possess properties of mammary stem / progenitor cells. Materials and Methods: In the present study, we used this cell system to test the idea that other known hMEC-immortalizing oncogenes (RhoA, HPVE6, HPVE7, p53 mutant, and treatment with g-radiation), share with hTERT, the ability to maintain mammary stem / progenitor cells. Results: The results presented here demonstrate that similar to hMECs immortalized with hTERT, all hMEC cell lines immortalized using various oncogenic strategies express stem / progenitor cell markers. Furthermore, analyses using 2D and 3D culture assays demonstrate that all the immortal cell lines retain their ability to self-renew and to differentiate along the luminal lineage. Remarkably, the stem / progenitor cell lines generated using various oncogenic strategies exhibit a block in differentiation along the myoepithelial lineage, a trait that is retained on hTERT-immortalized stem / progenitors. The inability to differentiate along the myoepithelial lineage could be induced by ectopic mutant p53 expression in hTERT-immortalized hMEC. Conclusions: Our studies demonstrate that stem / progenitor cell characteristics of hMECs are maintained upon immortalization by using various cancer-relevant oncogenic strategies. Oncogene-immortalized hMECs show a block in their ability to differentiate along the myoepithelial lineage. Abrogation of the myoepithelial differentiation potential by a number of distinct oncogenic insults suggests a potential explanation for the predominance of luminal and rarity of myoepithelial breast cancers.

Shared signaling pathways in normal and breast cancer stem cells

Gautam K Malhotra — Sat,31 Dec 2011

Gautam K Malhotra, Xiangshan Zhao, Hamid Band, Vimla Band

Journal of Carcinogenesis 2011 10(1):38-38

Recent advances in our understanding of breast cancer biology have led to the identification of a subpopulation of cells within tumors that appear to be responsible for initiating and propagating the cancer. These tumor initiating cells are not only unique in their ability to generate tumors, but also share many similarities with elements of normal adult tissue stem cells, and have therefore been termed cancer stem cells (CSCs). These CSCs often inappropriately use many of the same signaling pathways utilized by their normal stem cell counterparts which may present a challenge to the development of CSC specific therapies. Here, we discuss three major stem cell signaling pathways (Notch, Wnt, and Hedgehog); with a focus on their function in normal mammary gland development and their misuse in breast cancer stem cell fate determination.

Oncogenic activation of ERG: A predominant mechanism in prostate cancer

Taduru L Sreenath — Sat,31 Dec 2011

Taduru L Sreenath, Albert Dobi, Gyorgy Petrovics, Shiv Srivastava

Journal of Carcinogenesis 2011 10(1):37-37

Prevalent gene fusions involving regulatory sequences of the androgen receptor (AR) regulated genes (primarily TMPRSS2) and protein coding sequences of nuclear transcription factors of the ETS gene family (predominantly ERG) result in unscheduled androgen dependent ERG expression in prostate cancer (CaP).Cumulative data from a large number of studies in the past six years accentuate ERG alterations in more than half of all CaP patients in Western countries. Studies underscore that ERG functions are involved in the biology of CaP. ERG expression in normal context is selective to endothelial cells, specific hematopoetic cells and pre-cartilage cells. Normal functions of ERG are highlighted in hematopoetic stem cells. Emerging data continues to unravel molecular and cellular mechanisms by which ERG may contribute to CaP. Herein, we focus on biological and clinical aspects of ERG oncogenic alterations, potential of ERG-based stratification of CaP and the possibilities of targeting the ERG network in developing new therapeutic strategies for the disease.

Emerging candidates in breast cancer stem cell maintenance, therapy resistance and relapse

Bhawna Sharma — Thu,22 Dec 2011

Bhawna Sharma, Rakesh K Singh

Journal of Carcinogenesis 2011 10(1):36-36

Therapy resistance is a major concern while treating breast cancer. Various mechanisms have been proposed, but so far nothing has been able to effectively address this problem. Accumulating evidences suggest that a subset of cancer cells provides survival benefits to the tumor and are responsible for therapy resistance and relapse of cancer. These so called the cancer stem cells, are known to be regulated by several pathways. Evidences shows that the tumor microenvironment plays a crucial role in maintaining the cancer stem cell pool. Signaling within the tumor is modulated by surrounding cells which secrete signals favoring tumor growth and metastasis. In breast cancer, the cancer stem cells have recently been reported to be influenced by tumor microenvironment via cytokines which act as chemoattractants for leukocytes. This review elucidates the emerging role of chemokine receptor and receptor activator of NFκB (RANK) ligand/RANK signaling pathways in mediating therapy resistance of breast cancer by maintaining the cancer stem cell pool.

Mouse models of estrogen receptor-positive breast cancer

Shakur Mohibi — Thu,22 Dec 2011

Shakur Mohibi, Sameer Mirza, Hamid Band, Vimla Band

Journal of Carcinogenesis 2011 10(1):35-35

Breast cancer is the most frequent malignancy and second leading cause of cancer-related deaths among women. Despite advances in genetic and biochemical analyses, the incidence of breast cancer and its associated mortality remain very high. About 60 - 70% of breast cancers are Estrogen Receptor alpha (ER-α) positive and are dependent on estrogen for growth. Selective estrogen receptor modulators (SERMs) have therefore provided an effective targeted therapy to treat ER-α positive breast cancer patients. Unfortunately, development of resistance to endocrine therapy is frequent and leads to cancer recurrence. Our understanding of molecular mechanisms involved in the development of ER-α positive tumors and their resistance to ER antagonists is currently limited due to lack of experimental models of ER-α positive breast cancer. In most mouse models of breast cancer, the tumors that form are typically ER-negative and independent of estrogen for their growth. However, in recent years more attention has been given to develop mouse models that develop different subtypes of breast cancers, including ER-positive tumors. In this review, we discuss the currently available mouse models that develop ER-α positive mammary tumors and their potential use to elucidate the molecular mechanisms of ER-α positive breast cancer development and endocrine resistance.

MicroRNA alterations in Barrett's esophagus, esophageal adenocarcinoma, and esophageal adenocarcinoma cell lines following cranberry extract treatment: Insights for chemoprevention

Laura A Kresty — Thu,22 Dec 2011

Laura A Kresty, Jennifer Clarke, Kristin Ezell, Amy Exum, Amy B Howell, Toumy Guettouche

Journal of Carcinogenesis 2011 10(1):34-34

Background: Aberrant expression of small noncoding endogenous RNA molecules known as microRNAs (miRNAs) is documented to occur in multiple cancer types including esophageal adencarcinoma (EAC) and its only known precursor, Barrett's esophagus (BE). Recent studies have linked dysregulation of specific miRNAs to histological grade, neoplastic progression and metastatic potential. Materials and Methods: Herein, we present a summary of previously reported dysregulated miRNAs in BE and EAC tissues as well as EAC cell lines and evaluate a cranberry proanthocyanidin rich extract's (C-PAC) ability to modulate miRNA expression patterns of three human EAC cell lines (JHEso-Ad-1, OE33 and OE19). Results: A review of 13 published studies revealed dysregulation of 87 miRNAs in BE and EAC tissues, whereas 52 miRNAs have been reported to be altered in BE or EAC cell lines, with 48% overlap with miRNA changes reported in tissues. We report for the first time C-PAC-induced modulation of five miRNAs in three EAC cell lines resulting in 26 validated gene targets and identification of key signaling pathways including p53, angiogenesis, T-cell activation and apoptosis. Additionally, mutiple cancer related networks were ideintified as modulated by C-PAC utilizing Kyoto Encyclopedia of Genes and Genomes (KEGG), Protein Analysis Through Evolutionary Relationships (PANTHER), and MetaCore analysis tools. Conclusions: Study results support the cancer inhibitory potential of C-PAC is in part attributable to C-PAC's ability to modify miRNA profiles within EAC cells. A number of C-PAC-modulated miRNAs have been been identified as dysregulated in BE and EAC. Further insights into miRNA dysregulation and modulation by select cancer preventive agents will support improved targeted interventions in high-risk cohorts.

Hormones and prostate carcinogenesis: Androgens and estrogens

Maarten C Bosland — Thu,8 Dec 2011

Maarten C Bosland, Abeer M Mahmoud

Journal of Carcinogenesis 2011 10(1):33-33

Prostate cancer is the leading non-skin malignancy detected in US males and the second cause of death due to male cancer in the US. Androgenic hormones are generally believed to be causatively associated with prostate carcinogenesis, but human evidence, mostly epidemiological, for this is minimal. Circulating hormone levels are not associated with the risk of prostate cancer and neither are polymorphisms in various genes encoding the androgen metabolizing enzymes or androgen receptors. Evidence in support of the involvement of androgens in prostate cancer development is derived from clinical trials with 5α-reductase inhibitors, which reduced the risk by approximately 25%. Animal studies using rat models, however, provide clear evidence that testosterone can induce prostate cancer and can act as a strong tumor promoter in concert with genotoxic carcinogens. One such genotoxic factor may be 17β-estradiol, which is generated from testosterone by the aromatase enzyme. Estradiol can be converted to catecholestrogens, which through redox cycling, generate reactive metabolites that can adduct the DNA and potentially lead to mutations. Animal studies and limited human evidence suggest that estrogens can be involved in prostate carcinogenesis by such a genotoxic mechanism. However, how androgens exert their tumor-promoting effect is not clear. It is likely that hormonal and non-hormonal factors as well as genetic and non-genetic (environmental) factors interact in a highly complex and poorly understood manner to determine the risk of prostate cancer.

The two faces of Janus kinases and their respective STATs in mammary gland development and cancer

Kay-Uwe Wagner — Thu,8 Dec 2011

Kay-Uwe Wagner, Jeffrey W Schmidt

Journal of Carcinogenesis 2011 10(1):32-32

Since its discovery as "just another kinase" more than twenty years ago, the family of JAK tyrosine kinases and their respective Signal Transducers and Activators of Transcription (STATs) has been a center of attention in the areas of signal transduction, development, and cancer. The subsequent designation of JAKs as Janus kinases after the mythical two-faced Roman God of the doorways accurately portrays the analogous and sometimes contrasting molecular and biological characteristics of these tyrosine kinases. The two "faces" of JAKs are their structurally similar kinase and pseudo-kinase domains. As essential parts of various transmembrane receptor complexes, these tyrosine kinases function at cellular gateways and relay signals from growth factors to their respective intracellular targets. The multifaceted nature of JAKs becomes evident from their ability to activate specific STATs during distinct phases of normal mammary gland development. Studies in breast cancer cells and genetically engineered mouse models also show that JAK/STAT signaling possesses a "two-faced" role during breast cancer initiation and progression. This review will highlight recent findings about important biological functions of JAKs and STATs during normal mammogenesis, with particular emphasis on the Jak2/Stat5 pathway as well as Jak1/2/Stat3 signaling complexes. In addition, we will discuss how the importance of these signaling networks changes during carcinogenesis. With JAK inhibitors currently under development to treat myeloproliferative disorders, determining the essential functions of JAKs at particular stages of disease initiation and progression is of critical importance to predict the efficacy of these agents for targeted therapies against breast cancer.

Paget's disease of the breast

Cansu Karakas — Thu,8 Dec 2011

Cansu Karakas

Journal of Carcinogenesis 2011 10(1):31-31

Paget's disease of the breast is a rare type of cancer of the nipple-areola complex and that is often associated with an underlying in situ or invasive carcinoma. This article provides an overview and we review the main clinicopathological and therapeutic features of mammary Paget's disease.

Diabetes mellitus and gastric carcinoma: Is there an association?

Sathiya P Marimuthu — Fri,2 Dec 2011

Sathiya P Marimuthu, Paari Vijayaragavan, Kirsten B Moysich, Vijayvel Jayaprakash

Journal of Carcinogenesis 2011 10(1):30-30

Diabetes mellitus (DM) has been associated with the risk of several gastrointestinal cancers including liver, pancreas, colon and rectum. However, the evidence is inconclusive for gastric adenocarcinoma (GC). In the current review, we summarize 20 population-based cohort studies that compared GC incidence and mortality between diabetic and non-diabetic population. We discuss the shared risk factors and provide qualitative and quantitative (meta-analytic) summary of the current evidence evaluating the association by high-risk subgroups. The overall risk-estimate based on all studies did not show an increased risk of GC in diabetics. However, 2 cohort studies conducted in East Asian countries, where Helicobacter pylori infection and GC rates are higher, showed a higher risk of GC in diabetics. Additionally, high plasma glucose levels in the presence of Helicobacter pylori infection increased the risk of GC by over four times, suggesting a multiplicative effect. Results from the meta-analysis show that, the risk of GC was also higher in populations with greater prevalence of type 1 DM (relative risk = 1.60), suggesting an insulin-independent carcinogenic process in this subgroup. The risk of mortality due to GC was higher in diabetics compared to non-diabetics (relative risk = 1.62). Although the overall risk estimates do not show an association between DM and GC, complex interactions between infectious, molecular, demographic and host factors may convey a higher risk in certain subgroups. Future studies should be sufficiently powered for detailed subgroup analysis to elucidate the causative and mechanistic association between DM and GC.

Continuous requirement of ErbB2 kinase activity for loss of cell polarity and lumen formation in a novel ErbB2/Neu-driven murine cell line model of metastatic breast cancer

Cesar F Ortega-Cava — Wed,30 Nov 2011

Cesar F Ortega-Cava, Srikumar M Raja, Zenab Laiq, Tameka A Bailey, Haitao Luan, Bhopal Mohapatra, Stetson H Williams, Aaron C Ericsson, Rasna Goswami, Manjari Dimri, Lei Duan, Vimla Band, Mayumi Naramura, Hamid Band

Journal of Carcinogenesis 2011 10(1):29-29

Background: Well over a quarter of human breast cancers are ErbB2-driven and constitute a distinct subtype with substantially poorer prognosis. Yet, there are substantial gaps in our understanding of how ErbB2 tyrosine kinase activity unleashes a coordinated program of cellular and extracellular alterations that culminate in aggressive breast cancers. Cellular models that exhibit ErbB2 kinase dependency and can induce metastatic breast cancer in immune competent hosts are likely to help bridge this gap. Materials and Methods: Here, we derived and characterized a cell line model obtained from a transgenic ErbB2/Neu-driven mouse mammary adenocarcinoma. Results: The MPPS1 cell line produces metastatic breast cancers when implanted in the mammary fat pads of immune-compromised as well as syngeneic immune-competent hosts. MPPS1 cells maintain high ErbB2 overexpression when propagated in DFCI-1 or related media, and their growth is ErbB2-dependent, as demonstrated by concentration-dependent inhibition of proliferation with the ErbB kinase inhibitor Lapatinib. When grown in 3-dimensional (3-D) culture on Matrigel, MPPS1 cells predominantly form large irregular cystic and solid structures. Remarkably, low concentrations of Lapatinib led to a switch to regular acinar growth on Matrigel. Immunofluorescence staining of control vs. Lapatinib-treated acini for markers of epithelial polarity revealed that inhibition of ErbB2 signaling led to rapid resumption of normal mammary epithelium-like cell polarity. Conclusions: The strict dependence of the MPPS1 cell system on ErbB2 signals for proliferation and alterations in cell polarity should allow its use to dissect ErbB2 kinase-dependent signaling pathways that promote loss of cell polarity, a key component of the epithelial mesenchymal transition and aggressiveness of ErbB2-driven breast cancers.

Mechanisms of Trastuzumab resistance in ErbB2-driven breast cancer and newer opportunities to overcome therapy resistance

Tameka A Bailey — Wed,30 Nov 2011

Tameka A Bailey, Haitao Luan, Robert J Clubb, Mayumi Naramura, Vimla Band, Srikumar M Raja, Hamid Band

Journal of Carcinogenesis 2011 10(1):28-28

The Human Epidermal Growth Factor Receptor 2 (Her2, ErbB2 or Neu) is overexpressed in about 20 - 25% of breast cancers and is causally linked to oncogenesis, providing opportunities for targeted therapy. Trastuzumab (Herceptin™, Genentech Inc, San Francisco, CA), a humanized monoclonal antibody against ErbB2, is a successful example of this concept and has vastly improved the response to treatment and overall survival in a majority of ErbB2+ breast cancer patients. However, lack of response in some patients as well as relapse during the course of therapy in others, continue to challenge researchers and clinicians alike towards a better understanding of the fundamental mechanisms of Trastuzumab action and resistance to treatment. The exact in vivo mechanism of action of Trastuzumab remains enigmatic, given its direct effects on the ErbB2 signaling pathway as well as indirect contributions from the immune system, by virtue of the ability of Trastuzumab to elicit Antibody-Dependent Cellular Cytotoxicity. Consequently, multiple mechanisms of resistance have been proposed. We present here a comprehensive review of our current understanding of the mechanisms, both of Trastuzumab action and clinical resistance to Trastuzumab-based therapies. We also review newer strategies (based on ErbB2 receptor biology) that are being explored to overcome resistance to Trastuzumab therapy.

Chemoprevention of prostate cancer: Natural compounds, antiandrogens, and antioxidants - In vivo evidence

Nur Özten-Kandas — Wed,30 Nov 2011

Nur Özten-Kandas, Maarten C Bosland

Journal of Carcinogenesis 2011 10(1):27-27

Prostate cancer is the leading non-skin malignancy detected in US males and the second cause of death due to male cancer, in the US. Interventions with drugs or diet supplements that slow down the growth and progression of prostate cancer are potentially very effective in reducing the burden of prostate cancer, particularly if these treatments also prevent the de novo development of new prostatic malignancies. Challenges to identify efficacious agents and develop them for chemopreventive application in men at risk for prostate cancer have included uncertainty about which preclinical models have the ability to predict efficacy in men and lack of consensus about which early phase clinical trial designs are the most appropriate and cost-effective to test promising agents. Efficacy studies in animal models have identified several agents with potential chemopreventive activity against prostate cancer, but few of these findings have been translated into clinical trials. This article identifies some of the major issues associated with prostate cancer chemoprevention research and summarizes the most significant current results from animal efficacy studies and human clinical prevention trials. This summary focuses on: (1) Naturally occurring agents and compounds derived from such agents, including green tea and its constituents, silibinin and milk thistle, and genistein and soy, (2) chemoprevention drugs including agents interfering with androgen action, and (3) antioxidants such as selenium, vitamin E, and lycopene. The general lack of activity of antioxidants is discussed, followed by considerations about translation of preclinical chemoprevention efficacy data, focusing on dose, form, bioavailability, and timing of administration of the agent, as well as discussion of study design of clinical trials and the predictive ability of preclinical models.

Exploration of structural stability in deleterious nsSNPs of the XPA gene: A molecular dynamics approach

N NagaSundaram — Wed,30 Nov 2011

N NagaSundaram, C George Priya Doss

Journal of Carcinogenesis 2011 10(1):26-26

Background: Distinguishing the deleterious from the massive number of non-functional nsSNPs that occur within a single genome is a considerable challenge in mutation research. In this approach, we have used the existing in silico methods to explore the mutation-structure-function relationship in the XPA gene. Materials and Methods: We used the Sorting Intolerant From Tolerant (SIFT), Polymorphism Phenotyping (PolyPhen), I-Mutant 2.0, and the Protein Analysis THrough Evolutionary Relationships methods to predict the effects of deleterious nsSNPs on protein function and evaluated the impact of mutation on protein stability by Molecular Dynamics simulations. Results: By comparing the scores of all the four in silico methods, nsSNP with an ID rs104894131 at position C108F was predicted to be highly deleterious. We extended our Molecular dynamics approach to gain insight into the impact of this non-synonymous polymorphism on structural changes that may affect the activity of the XPA gene. Conclusion: Based on the in silico methods score, potential energy, root-mean-square deviation, and root-mean-square fluctuation, we predict that deleterious nsSNP at position C108F would play a significant role in causing disease by the XPA gene. Our approach would present the application of in silico tools in understanding the functional variation from the perspective of structure, evolution, and phenotype.

Breaking the cycle: An insight into the role of ERα in eukaryotic cell cycles

Sonia Javan Moghadam — Wed,30 Nov 2011

Sonia Javan Moghadam, Amanda M Hanks, Khandan Keyomarsi

Journal of Carcinogenesis 2011 10(1):25-25

There have been numerous reviews written to date on estrogen receptor (ER), focusing on topics such as its role in the etiology of breast cancer, its mode of regulation, its role as a transcriptional activator and how to target it therapeutically, just to name a few. One reason for so much attention on this nuclear receptor is that it acts not only as a prognostic marker, but also as a target for therapy. However, a relatively undiscovered area in the literature regarding ER is how its activity in the presence and absence of ligand affects its role in proliferation and cell cycle transition. In this review, we provide a brief overview of ER signaling, ligand dependent and independent, genomic and non-genomic, and how these signaling events affect the role of ER in the mammalian cell cycle.

Cyclin D1 inhibits whereas c-Myc enhances the cytotoxicity of cisplatin in mouse pancreatic cancer cells via regulation of several members of the NF-κB and Bcl-2 families

Ayman El-Kady — Wed,30 Nov 2011

Ayman El-Kady, Yuan Sun, Ying-xia Li, D Joshua Liao

Journal of Carcinogenesis 2011 10(1):24-24

Background: Cisplatin (CDDP) is a drug used for treatment of many types of malignancy but pancreatic cancer is relatively resistant to it. This study aims to determine whether and how cyclin D1 (D1) and c-Myc influence the response of pancreatic cancer cells to CDDP. Materials and Methods: Ela-mycPT mouse pancreatic cancer cells were transfected with D1 or c-myc cDNA and treated with CDDP alone or together with NPCD, an inhibitor of cyclin dependent ckinase (CDK) 4 and 6. Reverse transcription followed by polymerase chain reaction (RT-PCR) and western blot assays were used to determine the mRNA and protein levels of interested genes. Cell viability was determined using 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Results: Treatment of Ela-mycPT1 cells with CDDP caused an increase in c-myc expression but a slightly latent decrease in D1 expression, whereas D1 and c-Myc proteins repressed each other. D1 or c-Myc rendered Ela-mycPT1 cells resistant or sensitive, respectively, to CDDP. D1 induced the expression of several members of the NF-κB family, including RelA, RelB, Nfκb1 and Nfκb2. D1 also induced BIRC5 and several pro-survival members of the Bcl-2 gene family, including Bcl-2, Mcl-1 and Bad while it decreased the level of the pro-apoptotic Noxa. Inhibition of CDK4 or CDK6 kinase activity by NPCD did not affect these effects of D1. In contrast, c-Myc in Ela-mycPT1 and Ela-mycPT4 cells has the opposite effects to D1 on the expression of most of these apoptosis regulating genes. Conclusion: Our results suggest that induction of c-Myc and inhibition of D1 may be mechanisms for CDDP to elicit cytotoxicity. On the other hand, D1 induces whereas c-Myc represses the expression of key NF-κB family members to induce and repress, respectively, the expression of BIRC5 and several Bcl-2 family members, in turn inhibiting or enhancing the response to CDDP.

Optimizing therapeutic efficacy of chemopreventive agents: A critical review of delivery strategies in oral cancer chemoprevention clinical trials

Andrew S Holpuch — Wed,21 Sep 2011

Andrew S Holpuch, Kashappa-Goud H Desai, Steven P Schwendeman, Susan R Mallery

Journal of Carcinogenesis 2011 10(1):23-23

Due to its characterized progression from recognized premalignant oral epithelial changes (i.e., oral epithelial dysplasia) to invasive cancer, oral squamous cell carcinoma represents an optimal disease for chemopreventive intervention prior to malignant transformation. The primary goal of oral cancer chemoprevention is to reverse, suppress, or inhibit the progression of premalignant lesions to cancer. Over the last several decades, numerous oral cancer chemoprevention clinical trials have assessed the therapeutic efficacy of diverse chemopreventive agents. The standard of care for more advanced oral dysplastic lesions entails surgical excision and close clinical follow-up due to the potential (~33%) for local recurrence at a similar or more advanced histological stage. The purpose of this review was to identify prominent oral cancer chemoprevention clinical trials, assess their overall therapeutic efficacy, and delineate effects of local versus systemic drug administration. In addition, these compiled clinical trial data present concepts for consideration in the design and conduction of future clinical trials.

Toward the identification of communities with increased tobacco-associated cancer burden: Application of spatial modeling techniques

Noella A Dietz — Wed,21 Sep 2011

Noella A Dietz, Recinda Sherman, Jill MacKinnon, Lora Fleming, Kristopher L Arheart, Brad Wohler, David J Lee

Journal of Carcinogenesis 2011 10(1):22-22

Introduction: Smoking-attributable risks for lung, esophageal, and head and neck (H/N) cancers range from 54% to 90%. Identifying areas with higher than average cancer risk and smoking rates, then targeting those areas for intervention, is one approach to more rapidly lower the overall tobacco disease burden in a given state. Our research team used spatial modeling techniques to identify areas in Florida with higher than expected tobacco-associated cancer incidence clusters. Materials and Methods: Geocoded tobacco-associated incident cancer data from 1998 to 2002 from the Florida Cancer Data System were used. Tobacco-associated cancers included lung, esophageal, and H/N cancers. SaTScan was used to identify geographic areas that had statistically significant (P<0.10) excess age-adjusted rates of tobacco-associated cancers. The Poisson-based spatial scan statistic was used. Phi correlation coefficients were computed to examine associations among block groups with/without overlapping cancer clusters. The logistic regression was used to assess associations between county-level smoking prevalence rates and being diagnosed within versus outside a cancer cluster. Community-level smoking rates were obtained from the 2002 Florida Behavioral Risk Factor Surveillance System (BRFSS). Analyses were repeated using 2007 BRFSS to examine the consistency of associations. Results: Lung cancer clusters were geographically larger for both squamous cell and adenocarcinoma cases in Florida from 1998 to 2002, than esophageal or H/N clusters. There were very few squamous cell and adenocarcinoma esophageal cancer clusters. H/N cancer mapping showed some squamous cell and a very small amount of adenocarcinoma cancer clusters. Phi correlations were generally weak to moderate in strength. The odds of having an invasive lung cancer cluster increased by 12% per increase in the county-level smoking rate. Results were inconsistent for esophageal and H/N cancers, with some inverse associations. 2007 BRFSS data also showed a similar results pattern. Conclusions: Spatial analysis identified many nonoverlapping areas of high risk across both cancer and histological subtypes. Attempts to correlate county-level smoking rates with cancer cluster membership yielded consistent results only for lung cancer. However, spatial analyses may be most useful when examining incident clusters where several tobacco-associated cancer clusters overlap. Focusing on overlapping cancer clusters may help investigators identify priority areas for further screening, detailed assessments of tobacco use, and/or prevention and cessation interventions to decrease risk.

The manner in which calories are restricted impacts mammary tumor cancer prevention

Margot P Cleary — Wed,21 Sep 2011

Margot P Cleary, Michael E Grossmann

Journal of Carcinogenesis 2011 10(1):21-21

Although treatments for breast cancer have improved and long-term survival after diagnosis is now common, prevention of the disease is the ultimate goal. Weight loss or weight maintenance is one approach that has been recommended to reduce the risk of breast cancer, particularly for peri/postmenopausal women. This approach is supported by decades of data indicating that calorie restriction prevents spontaneous and chemically induced mammary tumor development in rodents. In most cases, calorie restriction was implemented by a consistent daily reduction of calories, i.e. chronic calorie restriction (CCR). There have also been several studies where periods of reduced caloric intake were followed by periods of refeeding, i.e. intermittent calorie restriction (ICR), resulting in the prevention of spontaneous mammary tumorigenesis. In most of the early studies, there were no direct comparisons of CCR to ICR. One study using moderate calorie restriction in a chemically induced breast cancer rat model found a slight increase in mammary tumor incidence compared with ad libitum fed and CCR rats. However, recently, it has been demonstrated in several transgenic mouse models of breast cancer that ICR consistently provided a greater degree of protection than CCR. This review will provide a detailed comparison of ICR and CCR for breast cancer prevention. It will also examine potential mechanisms of action that may include periods of reduced IGF-I and leptin as well as an increase in the adiponectin:leptin ratio. Application of this approach to at-risk women may provide an approach to lower the risk of breast cancer in overweight/obese women.

Androgen receptor signaling in prostate cancer development and progression

Peter E Lonergan — Tue,23 Aug 2011

Peter E Lonergan, Donald J Tindall

Journal of Carcinogenesis 2011 10(1):20-20

The androgen receptor (AR) signaling axis plays a critical role in the development, function and homeostasis of the prostate. The classical action of AR is to regulate gene transcriptional processes via AR nuclear translocation, binding to androgen response elements on target genes and recruitment of, or crosstalk with, transcription factors. Prostate cancer initiation and progression is also uniquely dependent on AR. Androgen deprivation therapy remains the standard of care for treatment of advanced prostate cancer. Despite an initial favorable response, almost all patients invariably progress to a more aggressive, castrate-resistant phenotype. Considerable evidence now supports the concept that development of castrate-resistant prostate cancer (CRPC) is causally related to continued transactivation of AR. Understanding the critical events and complexities of AR signaling in the progression to CRPC is essential in developing successful future therapies. This review provides a synopsis of AR structure and signaling in prostate cancer progression, with a special focus on recent findings on the role of AR in CRPC. Clinical implications of these findings and potential directions for future research are also outlined.

Development of angle-resolved low coherence interferometry for clinical detection of dysplasia

Yizheng Zhu — Tue,23 Aug 2011

Yizheng Zhu, Neil G Terry, Adam Wax

Journal of Carcinogenesis 2011 10(1):19-19

This review covers the development of angle-resolved low coherence interferometry (a/LCI) from initial development through clinical application. In the first applications, the approach used a time-domain interferometry scheme and was validated using animal models of carcinogenesis to assess the feasibility of detecting dysplasia in situ. Further development of the approach led to Fourier-domain interferometry schemes with higher throughput and endoscope-compatible probes to enable clinical application. These later implementations have been applied to clinical studies of dysplasia in Barrett's esophagus tissues, a metaplastic tissue type that is associated with an increased risk of esophageal adenocarcinoma. As an alternative to systematic biopsy, the a/LCI approach offers high sensitivity and specificity for detecting dysplasia in these tissues while avoiding the need for tissue removal or exogenous contrast agents. Here, the various implementations of a/LCI are discussed and the results of the preliminary animal experiments and ex vivo human tissue studies are reviewed. A review of a recent in vivo clinical study is also presented.

Cell phones are as carcinogenic as coffee

Gopala Kovvali — Tue,19 Jul 2011

Gopala Kovvali

Journal of Carcinogenesis 2011 10(1):18-18

Metformin as an energy restriction mimetic agent for breast cancer prevention

Zongjian Zhu — Tue,19 Jul 2011

Zongjian Zhu, Weiqin Jiang, Matthew D Thompson, John N McGinley, Henry J Thompson

Journal of Carcinogenesis 2011 10(1):17-17

Background: This study examined whether metformin administration inhibited chemically induced mammary carcinogenesis in rats. In cancer prevention, metformin may act (1) indirectly through reducing systemic risk factors; or (2) directly through AMPK-mediated signaling. To begin to delineate clinically relevant mechanisms for breast cancer prevention, metformin was also studied along with dietary energy restriction. Materials and Methods: Mammary cancer was induced in female Sprague--Dawley rats (50 mg/kg MNU, i.p.). Metformin was fed alone (AIN93G + 0.05 to 1.0% w/w metformin) or combined with 40% dietary energy restriction. Plasma analytes (e.g., insulin, glucose, IGF-1) and protein expression (e.g., AMPK, mTOR, Akt) in mammary carcinomas and liver were evaluated. Additional studies included (1) aldehyde dehydrogenase flow cytometry, to gauge potential for cancer-initiated cells in mammary carcinomas to respond to metformin; (2) cell culture, to understand dose response (0.02--20 mM) of different cancer cell line molecular subtypes to metformin; and (3) analysis of a rat mammary epithelial cell microarray database, to examine expression of genes related to metformin pharmacokinetics (e.g., organic cation transporters) and pharmacodynamics (e.g., complex I of electron transport). Results: While a dosing regimen of 1.0%/0.25% metformin-reduced palpable mammary carcinoma incidence, multiplicity, and tumor burden and prolonged latency, lower doses of metformin failed to inhibit carcinogenesis despite effects on plasma insulin. Human breast cancer cell growth inhibition in response to metformin was only observed at high concentrations. Poor in vivo and in vitro response to metformin may be the result of pharmacokinetic (OCT-1 expression was low in rat mammary cells; OCT-3 was downregulated in mammary carcinoma) and pharmacodynamic (complex I transcripts were higher in mammary epithelial cells from carcinomas versus uninvolved gland) effects. In combination with dietary energy restriction, metformin offered protection against new tumor occurrence following release from combined treatment. Flow cytometry indicated the presence of cancer-initiated cells in mammary carcinomas. Conclusions: As a single agent, metformin possessed limited cancer inhibitory activity. However, metformin may be an effective component of multiagent interventions that target cancer-initiated cells. There is a clear need to identify the conditions under which metformin is likely to benefit prevention and control of breast cancer.

Abstracts - Invited Speakers

Fri,17 Jun 2011

Journal of Carcinogenesis 2011 10(1):16-16

Abstracts - Poster Presentations

Fri,17 Jun 2011

Journal of Carcinogenesis 2011 10(1):15-15

Elevated levels of urinary 8-hydroxy-2′-deoxyguanosine and 8-isoprostane in esophageal squamous cell carcinoma

Mohammad-Hassan Khadem-Ansari — Sat,16 Apr 2011

Mohammad-Hassan Khadem-Ansari, Zahra Shahsavari, Yousef Rasmi, Rahim Mahmoodlo

Journal of Carcinogenesis 2011 10(1):14-14

Aims:To measure oxidative DNA and lipid damages, urinary levels of 8-hydroxy-2Ͳ-deoxyguanosine (8-OHdG), and 8-isoprostane in esophageal squamous cell carcinoma (SCC) patients and compare the values with that in controls. Materials and Methods: The urinary concentrations of 8-OHdG and 8-isoprostane were measured in 32 SCC patients (13 female/19 male; mean age: 61.4 ± 10.5 years) and 45 controls (22 female/23 male; mean age: 58.1 ± 8.3 years). Results: Squamous cell carcinoma patients showed significantly higher levels of urinary 8-OHdG (15.6 ± 5.1 ng/mg creatinine) than controls (5.8 ± 2.1 ng/mg creatinine) (P<.001). Increased urinary concentrations of 8-isoprostane were also detected in SCC patients (35.4 ± 6.5 ng/mmol creatinine) as compared to the controls (16.9 ± 4.0 ng/mmol creatinine) (P<.001). Conclusions: Our results show the presence of oxidative DNA and lipid damage in the SCC patients. This may have a connection to carcinogenesis in the esophagus.

Therapeutic prevention of colorectal carcinogenesis

Frank L Meyskens — Sat,16 Apr 2011

Frank L Meyskens

Journal of Carcinogenesis 2011 10(1):13-13

Statistical methods for assays with limits of detection: Serum bile acid as a differentiator between patients with normal colons, adenomas, and colorectal cancer

Bonnie LaFleur — Sat,16 Apr 2011

Bonnie LaFleur, Wooin Lee, Dean Billhiemer, Craig Lockhart, Junmei Liu, Nipun Merchant

Journal of Carcinogenesis 2011 10(1):12-12

In analytic chemistry a detection limit (DL) is the lowest measurable amount of an analyte that can be distinguished from a blank; many biomedical measurement technologies exhibit this property. From a statistical perspective, these data present inferential challenges because instead of precise measures, one only has information that the value is somewhere between 0 and the DL (below detection limit, BDL). Substitution of BDL values, with 0 or the DL can lead to biased parameter estimates and a loss of statistical power. Statistical methods that make adjustments when dealing with these types of data, often called left-censored data, are available in many commercial statistical packages. Despite this availability, the use of these methods is still not widespread in biomedical literature. We have reviewed the statistical approaches of dealing with BDL values, and used simulations to examine the performance of the commonly used substitution methods and the most widely available statistical methods. We have illustrated these methods using a study undertaken at the Vanderbilt-Ingram Cancer Center, to examine the serum bile acid levels in patients with colorectal cancer and adenoma. We have found that the modern methods for BDL values identify disease-related differences that are often missed, with statistically naive approaches.

Perspective: Chemoprevention of colorectal neoplasia: Translating scientific promise into clinical practice

Peter Lance — Sat,16 Apr 2011

Peter Lance, Patricia A Thompson

Journal of Carcinogenesis 2011 10(1):11-11

Defining the role of polyamines in colon carcinogenesis using mouse models

Natalia A Ignatenko — Sat,16 Apr 2011

Natalia A Ignatenko, Eugene W Gerner, David G Besselsen

Journal of Carcinogenesis 2011 10(1):10-10

Genetics and diet are both considered important risk determinants for colorectal cancer, a leading cause of death in the US and worldwide. Genetically engineered mouse (GEM) models have made a significant contribution to the characterization of colorectal cancer risk factors. Reliable, reproducible, and clinically relevant animal models help in the identification of the molecular events associated with disease progression and in the development of effictive treatment strategies. This review is focused on the use of mouse models for studying the role of polyamines in colon carcinogenesis. We describe how the available mouse models of colon cancer such as the multiple intestinal neoplasia (Min) mice and knockout genetic models facilitate understanding of the role of polyamines in colon carcinogenesis and help in the development of a rational strategy for colon cancer chemoprevention.

The AOM/DSS murine model for the study of colon carcinogenesis: From pathways to diagnosis and therapy studies

Mariangela De Robertis — Thu,24 Mar 2011

Mariangela De Robertis, Emanuela Massi, Maria Luana Poeta, Simone Carotti, Sergio Morini, Loredana Cecchetelli, Emanuela Signori, Vito Michele Fazio

Journal of Carcinogenesis 2011 10(1):9-9

Colorectal cancer (CRC) is a major health problem in industrialized countries. Although inflammation-linked carcinogenesis is a well accepted concept and is often observed within the gastrointestinal tract, the underlying mechanisms remain to be elucidated. Inflammation can indeed provide initiating and promoting stimuli and mediators, generating a tumour-prone microenvironment. Many murine models of sporadic and inflammation-related colon carcinogenesis have been developed in the last decade, including chemically induced CRC models, genetically engineered mouse models, and xenoplants. Among the chemically induced CRC models, the combination of a single hit of azoxymethane (AOM) with 1 week exposure to the inflammatory agent dextran sodium sulphate (DSS) in rodents has proven to dramatically shorten the latency time for induction of CRC and to rapidly recapitulate the aberrant crypt foci-adenoma-carcinoma sequence that occurs in human CRC. Because of its high reproducibility and potency, as well as the simple and affordable mode of application, the AOM/DSS has become an outstanding model for studying colon carcinogenesis and a powerful platform for chemopreventive intervention studies. In this article we highlight the histopathological and molecular features and describe the principal genetic and epigenetic alterations and inflammatory pathways involved in carcinogenesis in AOM/DSS-treated mice; we also present a general overview of recent experimental applications and preclinical testing of novel therapeutics in the AOM/DSS model.

Clinical trials update: Tertiary prevention of colorectal cancer

Jason A Zell — Thu,24 Mar 2011

Jason A Zell

Journal of Carcinogenesis 2011 10(1):8-8

Systematic enrichment analysis of gene expression profiling studies identifies consensus pathways implicated in colorectal cancer development

Jesús Lascorz — Thu,24 Mar 2011

Jesús Lascorz, Kari Hemminki, Asta Försti

Journal of Carcinogenesis 2011 10(1):7-7

Background: A large number of gene expression profiling (GEP) studies on colorectal carcinogenesis have been performed but no reliable gene signature has been identified so far due to the lack of reproducibility in the reported genes. There is growing evidence that functionally related genes, rather than individual genes, contribute to the etiology of complex traits. We used, as a novel approach, pathway enrichment tools to define functionally related genes that are consistently up- or down-regulated in colorectal carcinogenesis. Materials and Methods: We started the analysis with 242 unique annotated genes that had been reported by any of three recent meta-analyses covering GEP studies on genes differentially expressed in carcinoma vs normal mucosa. Most of these genes (218, 91.9%) had been reported in at least three GEP studies. These 242 genes were submitted to bioinformatic analysis using a total of nine tools to detect enrichment of Gene Ontology (GO) categories or Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. As a final consistency criterion the pathway categories had to be enriched by several tools to be taken into consideration. Results: Our pathway-based enrichment analysis identified the categories of ribosomal protein constituents, extracellular matrix receptor interaction, carbonic anhydrase isozymes, and a general category related to inflammation and cellular response as significantly and consistently overrepresented entities. Conclusions: We triaged the genes covered by the published GEP literature on colorectal carcinogenesis and subjected them to multiple enrichment tools in order to identify the consistently enriched gene categories. These turned out to have known functional relationships to cancer development and thus deserve further investigation.

Risk of second primary colorectal cancer among colorectal cancer cases: A population-based analysis

Kavitha P Raj — Thu,17 Mar 2011

Kavitha P Raj, Thomas H Taylor, Charlie Wray, Michael J Stamos, Jason A Zell

Journal of Carcinogenesis 2011 10(1):6-6

Background: Patients with history of colorectal cancer (CRC) are at increased risk for developing a second primary colorectal cancer (SPCRC) as compared to the general population. However, the degree of risk is uncertain. Here, we attempt to quantify the risk, using data from the large population-based California Cancer Registry (CCR). Materials and Methods: We analyzed the CCR data for cases with surgically-treated colon and rectal cancer diagnosed during the period 1990-2005 and followed through up to January 2008. We excluded those patients diagnosed with metastatic disease and those in whom SPCRC was diagnosed within 6 months of the diagnosis of the primary CRC. Standardized incidence ratios (SIR) with 95% confidence intervals (CI) were calculated to evaluate risk as compared to the underlying population after taking into account age, sex, ethnicity, and time at risk. Results: The study cohort consisted of 69809 cases with colon cancer and 34448 with rectal cancer. Among these patients there were 1443 cases of SPCRCs. The SIR for developing SPCRC was higher in colon cancer survivors (SIR=1.4; 95% CI: 1.3 to 1.5) as compared to the underlying population. The incidence of SPCRC was also higher in females (SIR=1.5; 95% CI: 1.3 to 1.6) and Hispanics (SIR=2.0; 95% CI: 1.7 to 2.4) with primary colon cancer. The SIR for developing an SPCRC was higher only among those whose initial tumor was located in the descending colon (SIR=1.6; 95% CI: 1.3 to 2.0) and proximal colon (SIR=1.4; 95% CI: 1.3 to 1.6). Conclusions: Our results confirm that CRC patients, especially females and Hispanics, are at a higher risk of developing SPCRC than the general population. Differential SPCRC risk by colorectal tumor subsite is dependent on gender and ethnicity, underscoring the heterogeneous nature of CRC.

Wnt signaling and colon carcinogenesis: Beyond APC

Rani Najdi — Thu,17 Mar 2011

Rani Najdi, Randall F Holcombe, Marian L Waterman

Journal of Carcinogenesis 2011 10(1):5-5

Activation of the Wnt signaling pathway via mutation of the adenomatous polyposis coli gene (APC) is a critical event in the development of colon cancer. For colon carcinogenesis, however, constitutive signaling through the canonical Wnt pathway is not a singular event. Here we review how canonical Wnt signaling is modulated by intracellular LEF/TCF composition and location, the action of different Wnt ligands, and the secretion of Wnt inhibitory molecules. We also review the contributions of non-canonical Wnt signaling and other distinct pathways in the tumor micro environment that cross-talk to the canonical Wnt pathway and thereby influence colon cancer progression. These 'non-APC' aspects of Wnt signaling are considered in relation to the development of potential agents for the treatment of patients with colon cancer. Regulatory pathways that influence Wnt signaling highlight how it might be possible to design therapies that target a network of signals beyond that of APC and β-catenin.

Role of protein kinase C β and vascular endothelial growth factor receptor in malignant pleural mesothelioma: Therapeutic implications and the usefulness of Caenorhabditis elegans model organism

Sivakumar Loganathan — Thu,3 Mar 2011

Sivakumar Loganathan, Rajani Kanteti, Shahid S Siddiqui, Essam El-Hashani, Maria Tretiakova, Hari Vigneswaran, Gustavo Cervantes, Viswanathan Natarajan, Aliya N Husain, Everett E Vokes, Hedy L Kindler, Ravi Salgia

Journal of Carcinogenesis 2011 10(1):4-4

Purpose: To examine the role of both protein kinase C (PKC)-β and vascular endothelial growth factor receptor (VEGFR)-2 in malignant pleural mesothelioma (MPM) using respective inhibitors, enzastaurin and KRN633. Materials and Methods: MPM cell lines, control cells, and a variety of archived MPM tumor samples were used to determine the protein expression levels of PKC-β, VEGFR-2, VEGF, and p-AKT. Effects of enzastaurin and KRN633 on phosphorylation status of key signaling molecules and viability of the mesothelioma cells were determined. The common soil nematode, Caenorhabditis elegans, was treated with enzastaurin to determine its suitability to screen for highly potent kinase inhibitors. Results: PKC-β1, PKC-β2 and VEGFR-2/KDR were overexpressed in MPM cell lines and MPM tumor tissues. Enzastaurin treatment resulted in significant loss in viability of VEGF induced cell proliferation; however, the effect of KRN633 was much less. Enzastaurin also dramatically decreased the phosphorylation of PKC-β, its downstream target p-AKT, and surprisingly, the upstream VEGFR-2. The combination of the two drugs at best was additive and similar results were obtained with respect to cell viability. Treatment of C. elegans with enzastaurin resulted in clear phenotypic changes and the worms were hypermotile with abnormal pattern and shape of eggs, suggesting altered fecundity. Conclusions: PKC-β1 and VEGFR-2 are both excellent therapeutic targets in MPM. Enzastaurin was better at killing MPM cells than KRN633 and the combination lacked synergy. In addition, we show here that C. elegans can be used to screen for the next generation inhibitors as treatment with enzastaurin resulted in clear phenotypic changes that could be assayed.

Circulating fibroblast growth factor-23 is associated with increased risk for metachronous colorectal adenoma

Elizabeth Jacobs — Sat,12 Feb 2011

Elizabeth Jacobs, Maria Elena Martinez, Julie Buckmeier, Peter Lance, Melissa May, Peter Jurutka

Journal of Carcinogenesis 2011 10(1):3-3

Background: Fibroblast growth factor-23 (FGF-23) is a phosphaturic peptide and a key component of an endocrine feedback loop along with the hormonal vitamin D metabolite 1,25(OH) 2 D. Vitamin D has been shown to be inversely related to colorectal neoplasia; therefore, we hypothesized that the effect of FGF-23 on vitamin D metabolite concentrations could have implications for the risk of colorectal neoplasia. Materials and Methods: The purpose of this study was to prospectively evaluate the association between circulating concentrations of FGF-23 and the risk of metachronous (recurrent) colorectal adenomas. FGF-23 levels were assessed in 100 male and female participants from the Ursodeoxycholic Acid Trial, 50 of whom had a metachronous colorectal adenoma and 50 who did not. Results: Compared to the lowest tertile of FGF-23, the adjusted odds ratios (95% CIs) for the second and third tertiles were 2.80 (0.94 to 8.31) and 3.41 (1.09 to 10.67), respectively (P-trend=.03). In a linear regression model, there was also a statistically significant inverse relationship between FGF-23 and 1,25(OH) 2 D (β-coefficient=-1.2; P=.001). In contrast, no statistically significant trend was observed between FGF-23 and 25(OH)D concentrations (β-coefficient=0.55; P=.10). Conclusions: The current work presents novel preliminary evidence of a relationship between FGF-23 and the risk for colorectal neoplasia. FGF-23 activity may be mediated through biologic effects on individual serum and colonic 1,25(OH) 2 D levels, or it may be independent from the vitamin D pathway. Further studies in larger populations are necessary for confirmation and expansion of these hypothesis-generating results.

Zoledronic acid directly suppresses cell proliferation and induces apoptosis in highly tumorigenic prostate and breast cancers

Hussain Almubarak — Sat,15 Jan 2011

Hussain Almubarak, Antonia Jones, Risa Chaisuparat, Ming Zhang, Timothy F Meiller, Mark A Scheper

Journal of Carcinogenesis 2011 10(1):2-2

Background: Bisphosphonates (BPs) were designed for the prevention of skeletal-related events secondary to bone metastases. The purpose of this study was to show that zoledronic acid (ZA) directly eradicates highly tumorigenic and potentially metastatic cancer cells. Materials and Methods: Human prostate and breast highly tumorigenic (PC3, MCF 7) and low- or non-tumorigenic (LNCaP, MCF 10a) cell lines, respectively, were exposed to different concentrations of ZA (0-10 μM). Reverse transcriptase double quantitative polymerase chain reaction was used for quantitative gene expression analysis. Apoptosis and cell proliferation were determined using microscopic observation and MTS assays. Western blot was used to confirm the translational effects of apoptotic genes on protein expression. Results: Human prostate and breast highly tumorigenic (PC3, MCF 7) and low- or non-tumorigenic (LNCaP, MCF 10a) cell lines, respectively, showed multiple genes demonstrating differential expressions, including TRAF, TRADD, BCL2, CASPASES and IAP families. Increasing ZA concentrations showed a greater concentration-time response on cell proliferation and apoptosis in the highly tumorigenic cells. These results were confirmed by both reversing and enhancing the effect of ZA on cell proliferation with caspase 3, 7 or survivin siRNA, respectively. Pro-apoptotic proteins bax and caspase 2, 3, 7 and 9 were up-regulated, while the anti-apoptotic proteins bcl2, birc3 and survivin were down-regulated only in the highly tumorigenic cells. Conclusions: This explains the ability of ZA to inhibit bony metastasis in highly tumorigenic cells compared with the low- or non-tumorigenic cells through a significant decrease in cell proliferation and increase in apoptosis through gene-regulated and translational-mediated down-regulation of survivin coupled with the inhibition of caspase 3 or 7. This has significant implications toward understanding the pharmacophysiology of BPs in metastasis and supports the clinically observed effect of BPs when administered adjunctively with anticancer drugs such as cyclophosphamide/methotrexate/5-fluorouracil, epirubicin in combination with cyclophosphamide or docetaxel, and doxorubicin.

Inhibitory effects of Indigofera aspalathoides on 20-methylcholanthrene-induced chemical carcinogenesis in rats

S Selva Kumar — Tue,11 Jan 2011

S Selva Kumar, CM Karrunakaran, M. R. K. Rao, MP Balasubramanian

Journal of Carcinogenesis 2011 10(1):1-1

Background: The anticancer and antioxidant effects of the aqueous extract of Indigofera aspalathoides on 20-methylcholanthrene (20-MCA) induced fibrosarcoma were investigated in male albino rats. Materials and Methods: The rats were divided into four different groups, each group consisting of six animals. Group I animals were served as normal control, Group II animals were fibrosarcoma-bearing animals after the incubation period, Group III animals were fibrosarcoma-bearing animals, treated with aqueous extract of I. aspalathoides intraperitoneally at a dose of 250 mg/kg b.w. for 30 days and Group IV animals were administered with the aqueous extract of I. aspalathoides alone, at a dose of 250 mg/kg b.w. for 30 days, served as drug control animals. After the experimental period, all the rats were weighed and killed by cervical decapitation. The serum was separated from the blood for analysis. The weights of the liver and the kidneys were noted. The fibrosarcoma was proved by pathological examinations. The liver and kidney tissues were excised and then homogenized in an ice-cold buffer. These tissues were used for biochemical analysis. Results: The activities of antioxidant enzymes, e.g. catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD), in blood serum, liver, and kidney of control and experimental animals, respectively, have been reported. Conclusion: The present observations suggested that the aqueous extract of I. aspalathoides treatment enhanced the recovery from 20-MCA-induced fibrosarcoma due to its antioxidants and antineoplastic properties.

Digitoxin activates EGR1 and synergizes with paclitaxel on human breast cancer cells

Linda Saxe Einbond — Thu,18 Nov 2010

Linda Saxe Einbond, Hsan-au Wu, Tao Su, Tangel Chang, Maya Panjikaran, Xiaomei Wang, Sarah Goldsberry

Journal of Carcinogenesis 2010 9(1):10-10

Background: Numerous studies have suggested that digitalis derivatives promise to be superior to existing adjuvant therapy for breast cancer as to effects and side-effects. In the present study, we have used gene expression analysis to determine the molecular action of digitoxin on breast cancer cells and assessed digitoxin's ability to synergize with the chemotherapy agent paclitaxel with respect to inhibition of cell proliferation. Materials and Methods: We treated (Her2 overexpressing, ER low) MDA-MB-453 human breast cancer cells with digitoxin at four doses {20 ng/ml (26 nM) to 1 μg/ml} and collected RNA at 6 h and 24 h for gene expression analysis. To examine the effects on ER positive cells, we treated MCF7 cells with digitoxin at 1 μg/ml and collected RNA for RT-PCR analysis. In addition, we assayed the growth inhibitory effect of low doses of digitoxin combined with paclitaxel and determined combination index values. Results: To reveal primary effects, we examined digitoxin's effect 6 h post-treatment with the highest dose, 1μg/ml, and found upregulation of the stress response genes EGR-1 and NAB2, lipid biosynthetic genes and the tumor suppressor gene p21, and downregulation of the mitotic cell cycle gene CDC16 and the replication gene PolR3B. RT-PCR analysis validated effects on stress response, apoptotic and cell cycle genes on MDA-MB-453 and MCF7 cells. Western blot analysis confirmed induction of EGR1 protein at 1 h and ATF3 at 24 h. Paclitaxel, as well as digitoxin, inhibited the in vitro activity of the purified Na+-K+-ATPase; digitoxin enhanced the growth inhibitory effects of paclitaxel on Her2 overexpressing breast cancer cells. Conclusions: Our studies show the potential of digitoxin to prevent and treat breast cancer and indicate that the combination of digitoxin and paclitaxel is a promising treatment for ER negative breast cancer. These findings are the first to alert physicians to the possible dangers to patients who take a combination of digitoxin and paclitaxel. The potential dangers ensuing when paclitaxel and digitoxin are combined are dependent on the dose of digitoxin.

Prognostic implications of carboxyl-terminus of Hsc70 interacting protein and lysyl-oxidase expression in human breast cancer

Neill Patani — Fri,12 Nov 2010

Neill Patani, Wen Jiang, Robert Newbold, Kefah Mokbel

Journal of Carcinogenesis 2010 9(1):9-9

Background: Ubiquitin modification of proteins influences cellular processes relevant to carcinogenesis. CHIP (carboxyl-terminus of Hsc70-interacting protein) is a chaperone-dependent E3 ubiquitin ligase, regulating the stability of heat shock protein 90 (HSP90) interacting proteins. CHIP is implicated in the modulation of estrogen receptor (ESR1) and Her-2/neu (ERBB2) stability. LOX (lysyl-oxidase) serves intracellular roles and catalyses the cross-linking of extracellular matrix (ECM) collagens and elastin. LOX expression is altered in human malignancies and their peri-tumoral stroma. However, paradoxical roles are reported. In this study, the level of mRNA expression of CHIP and LOX were assessed in normal and malignant breast tissue and correlated with clinico-pathological parameters. Materials and Methods: Breast cancer (BC) tissues (n = 127) and normal tissues (n = 33) underwent RNA extraction and reverse transcription; transcript levels were determined using real-time quantitative PCR and normalized against CK-19. Transcript levels were analyzed against TNM stage, nodal involvement, tumor grade and clinical outcome over a ten-year follow-up period. Results: CHIP expression decreased with increasing Nottingham Prognostic Index (NPI): NPI-1 vs. NPI-3 (12.2 vs. 0.2, P = 0.0264), NPI-2 vs. NPI-3 (3 vs. 0.2, P = 0.0275). CHIP expression decreased with increasing TNM stage: TNM-1 vs. TNM-2 (12 vs. 0, P = 0.0639), TNM-1 vs. TNM-2-4 (12 vs. 0, P = 0.0434). Lower transcript levels were associated with increasing tumor grade: grade 1 vs. grade 3 (17.7 vs. 0.3, P = 0.0266), grade 2 vs. grade 3 (5 vs. 0.3, P = 0.0454). The overall survival (OS) for tumors classified as 'low-level expression', was poorer than those with 'high-level expression' (118.1 vs. 152.3 months, P = 0.039). LOX expression decreased with increasing NPI: NPI-1 vs. NPI-2 (3 vs. 0, P = 0.0301) and TNM stage: TNM-1 = 3854639, TNM-2 = 908900, TNM-3 = 329, TNM-4 = 1.232 (P = NS). Conclusion: CHIP expression is associated with favorable prognostic parameters, including tumor grade, TNM stage and NPI. CHIP expression predicts OS. LOX expression is associated with improved NPI. In addition to their prognostic utility, mechanistic insights into tumor suppressor function may offer potential therapeutic strategies.

MicroRNAs and lung cancer: Biology and applications in diagnosis and prognosis

Reema Mallick — Tue,3 Aug 2010

Reema Mallick, Santosh Kumar Patnaik, Sai Yendamuri

Journal of Carcinogenesis 2010 9(1):8-8

MicroRNAs are tiny non-coding RNA molecules which play important roles in the epigenetic control of cellular processes by preventing the translation of proteins from messenger RNAs (mRNAs). A single microRNA can target different mRNAs, and an mRNA can be targeted by multiple microRNAs. Such complex interplays underlie many molecular pathways in cells, and specific roles for many microRNAs in physiological as well as pathological phenomena have been identified. Changes in expression of microRNAs have been associated with a wide variety of disease conditions, and microRNA-based biomarkers are being developed for the identification and monitoring of such states. This review provides a general overview of the current state of knowledge about the biology of microRNAs, and specific information about microRNAs with regard to the diagnosis and prognosis of lung cancer.

Dasatinib synergizes with JSI-124 to inhibit growth and migration and induce apoptosis of malignant human glioma cells

Daniel R Premkumar — Wed,14 Jul 2010

Daniel R Premkumar, Esther P Jane, Naomi R Agostino, Joseph L Scialabba, Ian F Pollack

Journal of Carcinogenesis 2010 9(1):7-7

Background: Src family kinases (SFK) collectively regulate a variety of cellular functions in many cancer types, including proliferation, invasion, motility, survival, differentiation, and angiogenesis. Although Dasatinib (BMS-354825), an ATP-competitive, small molecule tyrosine kinase inhibitor, suppresses the activity of SFKs at nanomolar concentrations, IC50 values for antiproliferative effects in glioma cell lines were well above the clinically achievable range, suggesting the need to interfere with other components of receptor-induced downstream signaling in order to achieve an optimal therapeutic effect. Materials and Methods: The cytotoxic effects of combining Src and STAT3 inhibition on glioma cell lines were evaluated using assays to measure cell proliferation, apoptosis and migration. Western blotting and immunocytochemistry was used to monitor its effects on cell signaling and morphology. Results: Silencing Src and STAT3 expression each partially inhibited cell proliferation and migration. In addition, JSI - 124 significantly enhanced the efficacy of dasatinib in vitro. Combination of dasatinib and JSI - 124 achieved significant inhibition of migration in all cell lines, which correlated with the inhibition of Src and downstream mediators of adhesion (e.g. focal adhesion kinase). Cells exposed to dasatinib and JSI-124 exhibited morphological changes that were consistent with an upstream role for Src in regulating focal adhesion complexes. Conclusions: Targeting the Src and STAT pathways may contribute to the treatment of cancers that demonstrate increased levels of these signaling mediators, including malignant human glioma. Clinical studies in these tumor types are warranted.

Biodegradation of the metallic carcinogen hexavalent chromium Cr(VI) by an indigenously isolated bacterial strain

Alok Prasad Das — Thu,20 May 2010

Alok Prasad Das, Susmita Mishra

Journal of Carcinogenesis 2010 9(1):6-6

Background : Hexavalent chromium [Cr(VI)], a potential mutagen and carcinogen, is regularly introduced into the environment through diverse anthropogenic activities, including electroplating, leather tanning, and pigment manufacturing. Human exposure to this toxic metal ion not only causes potential human health hazards but also affects other life forms. The World Health Organization, the International Agency for Research on Cancer, and the Environmental Protection Agency have determined that Cr(VI) compounds are known human carcinogens. The Sukinda valley in Jajpur District, Orissa, is known for its deposit of chromite ore, producing nearly 98% of the chromite ore in India and one of the prime open cast chromite ore mines in the world (CES, Orissa Newsletter). Materials and Methods: Our investigation involved microbial remediation of Cr(VI) without producing any byproduct. Bacterial cultures tolerating high concentrations of Cr were isolated from the soil sample collected from the chromite-contaminated sites of Sukinda, and their bioaccumulation properties were investigated. Strains capable of growing at 250 mg/L Cr(VI) were considered as Cr resistant. Results: The experimental investigation showed the maximum specific Cr uptake at pH 7 and temperature 30oC. At about 50 mg/L initial Cr(VI) concentrations, uptake of the selected potential strain exceeded 98% within 12 h of incubation. The bacterial isolate was identified by 16S rRNA sequencing as Brevebacterium casei. Conclusion: Results indicated promising approach for microbial remediation of effluents containing elevated levels of Cr(VI).

Oral administration of the anti-proliferative substance taurolidine has no impact on dextran sulfate sodium-induced colitis-associated carcinogenesis in mice

Ansgar Michael Chromik — Fri,16 Apr 2010

Ansgar Michael Chromik, Sebastian Huss, Hayssam Osseili, Adrien Daigeler, Sabine Kersting, Dominique Sulberg, Ulrich Mittelkotter, Thomas Herdegen, Waldemar Uhl, Annette M Muller

Journal of Carcinogenesis 2010 9(1):5-5

Background: New chemopreventive strategies for ulcerative colitis (UC)-associated dysplasia and cancer have to be evaluated. Taurolidine (TRD) has anti-inflammatory, anti-proliferative and anti-neoplastic properties with almost absent toxicity. The aim of the study was to determine whether TRD decreases dysplasia in the well-characterized Dextran Sulfate Sodium - Azoxymethane (DSS-AOM) animal model for UC-associated carcinogenesis. Material and Methods: The DSS-AOM model of carcinogenesis was induced in female inbred C57BL/6 mice. Half of the mice were treated with TRD, the other served as control. After 100 days macroscopic, histological and immunhistochemical (β-Catenin, E-Cadherin, SOX9, Ki-67, Cyclin-D1) examination of the colon was performed. Results: Incidence, multiplicity, grading and growth pattern of adenomas did not differ significantly between TRD and control group. In all animals, inflammatory changes were absent. Immunhistochemistry revealed increased expression of Ki-67, β-catenin, SOX9 and Cyclin-D1 in adenomas compared to normal mucosa - without significant difference between TRD and control treatment. Conclusion: Oral administration of TRD has no impact on DSS-induced colitis-associated carcinogenesis. However, SOX9 and Cyclin-D1 representing key members of the Wnt pathway have not yet been described in the DSS-AOM model of carcinogenesis - underlining the importance of this oncogenic pathway in this setting.

XRCC1 polymorphisms and breast cancer risk from the New York Site of the Breast Cancer Family Registry: A family-based case-control study

Jennifer Zipprich — Fri,16 Apr 2010

Jennifer Zipprich, Mary Beth Terry, Paul Brandt-Rauf, Greg A Freyer, Yuyan Liao, Meenakshi Agrawal, Irina Gurvich, Ruby Senie, Regina M Santella

Journal of Carcinogenesis 2010 9(1):4-4

Background: XRCC1 is a scaffold protein involved in the early and late stages of Base Excision Repair (BER). Three DNA polymorphisms occur in XRCC1, resulting in non-synonymous amino acid changes, which could alter the binding or regulatory activities of XRCC1. Materials and Methods: We used a family-based case-control study design to evaluate the association between XRCC1 polymorphisms and breast cancer risk. Participants were breast cancer cases and their unaffected sisters enrolled in the New York Site of the Breast Cancer Family Registry. Conditional logistic regression was used to assess associations between genotype and breast cancer. XRCC1 mRNA levels and DNA nicking activity were measured in lymphoblastoid cell lines from unaffected sisters to determine whether the XRCC1 R399Q polymorphism has a functional effect on expression or protein activity. Results: XRCC1 194W was associated with a non-significant increase in breast cancer, while XRCC1 280H and XRCC1 399Q were associated with a non-significant decrease in breast cancer. We found a significant increase in XRCC1 expression in 399Q/Q lymphoblastoid cell lines from unaffected sisters (n=28, P=0.03). An increase in median nicking activity was not statistically significant. Conclusions: Our results suggest that XRCC1 399Q may alter mRNA expression and DNA repair phenotype, although the main effects of the genotype were not significantly associated with familial cancer risk. Additional research on the regulation of XRCC1 expression will contribute to an understanding of how this polymorphism may impact disease risk.

Melanoma: Stem cells, sun exposure and hallmarks for carcinogenesis, molecular concepts and future clinical implications

Athanassios Kyrgidis — Thu,1 Apr 2010

Athanassios Kyrgidis, Thrasivoulos-George Tzellos, Stefanos Triaridis

Journal of Carcinogenesis 2010 9(1):3-3

Background :The classification and prognostic assessment of melanoma is currently based on morphologic and histopathologic biomarkers. Availability of an increasing number of molecular biomarkers provides the potential for redefining diagnostic and prognostic categories and utilizing pharmacogenomics for the treatment of patients. The aim of the present review is to provide a basis that will allow the construction-or reconstruction-of future melanoma research. Methods: We critically review the common medical databases (PubMed, EMBASE, Scopus and Cochrane CENTRAL) for studies reporting on molecular biomarkers for melanoma. Results are discussed along the hallmarks proposed for malignant transformation by Hanahan and Weinberg. We further discuss the genetic basis of melanoma with regard to the possible stem cell origin of melanoma cells and the role of sunlight in melanoma carcinogenesis. Results: Melanocyte precursors undergo several genome changes -UV-induced or not- which could be either mutations or epigenetic. These changes provide stem cells with abilities to self-invoke growth signals, to suppress anti-growth signals, to avoid apoptosis, to replicate without limit, to invade, proliferate and sustain angiogenesis. Melanocyte stem cells are able to progressively collect these changes in their genome. These new potential functions, drive melanocyte precursors to the epidermis were they proliferate and might cause benign nevi. In the epidermis, they are still capable of acquiring new traits via changes to their genome. With time, such changes could add up to transform a melanocyte precursor to a malignant melanoma stem cell. Conclusions : Melanoma cannot be considered a "black box" for researchers anymore. Current trends in the diagnosis and prognosis of melanoma are to individualize treatment based on molecular biomarkers. Pharmacogenomics constitute a promising field with regard to melanoma patients' treatment. Finally, development of novel monoclonal antibodies is expected to complement melanoma patient care while a number of investigational vaccines could find their way into everyday oncology practice.

Hypothesis: Towards the origin of cancer epidemics and pathogenesis

Sergey Rumyantsev — Wed,24 Mar 2010

Sergey Rumyantsev

Journal of Carcinogenesis 2010 9(1):2-2

Background: The article presents the initial results of an attempt to reconsider current data about cancer epidemiology and pathogenesis from the viewpoint of recent all-pathological, immunological, genetic and evolutionary discoveries. Methods: The investigation was based on a multidisciplinary approach to reassessment and reinterpretation of relevant current data about cancer epidemiology, clinical manifestations and course. Results: In contrast to the current 50-year-old hypothesis of mutant maternal tumor and its subsequent metastasis, the revealed set of evidences allowed hypothesize that potentially cancerous cell clone spreads in human population and settles some persons' bodies during cross-fertilization of parents with genetically incongruent regulators of cell dividing and tissue growth. The clone is formed and distributed in the offspring's body before postnatal ontogenesis and for many decades exists in it like sleeping populations of smallest sizes. But at a relevant time of an individual's life (mainly after 40 years of age), according to a specific program of the clone ontogenesis, the populations come into sight as constitutionally immune against prevailing regulators of cell reproduction and begin to multiple uncontrollably thus initiating the cancerous growth. Conclusions: The new view of cancer origin and pandemic spread supplies a framework for understanding the genetic nature of cancer epidemics and its rising incidence in the current worldwide population. It also forces one to reconsider the perspective of future investigations and reassess both the means and methods for cancer prevention and healing.

Spindle proteins are differentially expressed in the various histological subtypes of testicular germ cell tumors

Espen Burum-Auensen — Thu,4 Mar 2010

Espen Burum-Auensen, Rolf I Skotheim, Aasa R Schjolberg, Jo Roislien, Ragnhild A Lothe, Ole Petter F Clausen

Journal of Carcinogenesis 2010 9(1):1-1

Background: Testicular germ cell tumors (TGCTs) are characterized by an aneuploid DNA content. Aberrant expression of spindle proteins such as the Aurora kinases and the spindle checkpoint proteins MAD2 and BUB1B, are thought to contribute to the development of chromosomal instability and DNA aneuploidy in cancer. The importance of these spindle proteins remains unknown in the development of TGCTs, thus we have explored the expression levels of these proteins in normal and malignant testicular tissues. Materials and Methods: Using tissue microarrays the expression levels of Aurora kinase A (AURKA), Aurora kinase B (AURKB), BUB1B and MAD2 were measured in normal, preneoplastic and malignant testicular tissues of different histological subtypes from 279 orchidectomy specimens by means of immunohistochemistry. Results: All the spindle proteins except for AURKB were expressed in normal testis. Sixty-eight and 36%, respectively, of the primary spermatocytes in the normal testis were positive for BUB1B and MAD2, while only 5% of the cells were positive for AURKA. There was a significantly lower expression of the spindle checkpoint proteins in carcinoma in situ compared to normal testis (P=0.008 and P=0.043 for BUB1B and MAD2, respectively), while the level of AURKA was increased, however, not significantly (P=0.18). The extent of spindle protein expression varied significantly within the different histological subtypes of TGCTs (P<0.001 for AURKB, BUB1B and MAD2, P=0.003 for AURKA). The expression of AURKA was significantly elevated in both non-seminomas (P=0.003) and seminomas (P=0.015). The level of BUB1B was significantly decreased in non-seminomas (P<0.001). A similar tendency was observed for MAD2 (P=0.11). Conclusions: In carcinoma in situ of TGCTs the spindle checkpoint proteins MAD2 and BUB1B are significantly less expressed compared to normal testis, while the expression of AURKA is increased. We suggest that these changes may be of importance in the transition from in situ to invasive testicular cancer.

Estrogen receptor-dependent genomic expression profiles in breast cancer cells in response to fatty acids

Faizeh Alquobaili — Sun,27 Dec 2009

Faizeh Alquobaili, Stacy-Ann Miller, Seid Muhie, Agnes Day, Marti Jett, Rasha Hammamieh

Journal of Carcinogenesis 2009 8(1):17-17

Context: The estrogen receptor (ER) status in breast cancer plays a major role in the progression and metastatic potential of breast cancer in women. Breast cancer cells lacking the ER are usually more advanced and more difficult to treat than ER+ breast cancer cells. ER- women have more advanced breast cancer at the time of diagnosis than ER+ women. ER- breast cancer cells in women, regardless of age, are more likely to have tumor Grade III or IV with fewer Grade I and II tumor stages combined for each individual stage group. Studies have suggested a strong correlation between fat intake and the elevated risk of ER+ breast cancer cells. Materials and Methods: We studied the role of ER status on the gene expression in breast cancer cells in response to omega-3 and omega-6 fatty acids using microarrays. We have studied gene expression patterns in 8 breast cancer cell lines (4 ER- and 4 ER+) in response to Eicosapentanoic (EPA) and Arachidonic (AA) acids. Statistical Analysis: Analysis of Variance (ANOVA) t-test analysis was carried out to identify genes differentially expressed between the two groups. Results: We identified genes which were significantly correlated with the ER status when breast cancer cells were treated with these fatty acids. Conclusion: We have determined ER-related gene expression patterns in breast cancer cells in response to fatty acids. Additional studies of these biomarkers may enlighten the importance of the ER status on the mechanistic and therapeutic roles of fatty acids in breast cancer.

A color discriminating broad range cell staining technology for early detection of cell transformation

Idit Sagiv — Wed,16 Dec 2009

Idit Sagiv, Pavel Idelevich, Ilia Rivkin, Rimona Margalit, Adi Elkeles, Alexander Levitzki

Journal of Carcinogenesis 2009 8(1):16-16

Background: Advanced diagnostic tools stand today at the heart of successful cancer treatment. CellDetect® is a new histochemical staining technology that enables color discrimination between normal cells and a wide variety of neoplastic tissues. Using this technology, normal cells are colored blue/green, while neoplastic cells color red. This tinctorial difference coincides with clear morphological visualization properties, mainly in tissue samples. Here we show that the CellDetect® technology can be deployed to distinguish normal cells from transformed cells and most significantly detect cells in their early pre-cancerous transformed state. Materials and Methods: In tissue culture, we studied the ability of the CellDetect® technology to color discriminate foci in a number of two stage transformation systems as well as in a well defined cellular model for cervical cancer development, using HPV16 transformed keratinocytes. Results: In all these cellular systems, the CellDetect® technology was able to sensitively show that all transformed cells, including pre-cancerous HPV 16 transformed cells, are colored red, whereas normal cells are colored blue/green. The staining technology was able to pick up: (i) early transformation events in the form of small type 1 foci (non-invasive, not piled up small, with parallel alignment of cells), and (ii) early HPV16 transformed cells, even prior to their ability to form colonies in soft agar. The study shows the utility of the CellDetect® technology in early detection of transformation events.

MET/PKCß expression correlate with metastasis and inhibition is synergistic in lung cancer

Leonardo Faoro — Tue,24 Nov 2009

Leonardo Faoro, Gustavo M Cervantes, Benjamin D Ferguson, Tanguy Y Seiwert, Soheil Yala, Wicki T Vigneswaran, Maria Westerhoff, Maria S Tretiakova, Mark K Ferguson, Glaci L Moura, Aliya N Husain, Everett E Vokes, Ravi Salgia

Journal of Carcinogenesis 2009 8(1):15-15

Background: Treatment of non-small cell lung cancer (NSCLC) remains a difficult task in oncology. Targeted inhibition of oncogenic proteins is promising. In this study, we evaluate the expression of MET and PKCß and in vitro effects of their inhibition using SU11274 and enzastaurin (LY317615.HCl) respectively. Materials and Methods: Patient samples were analyzed by immunohistochemistry for expression of PKCß and MET, utilizing tissue microarrays under an IRB-approved protocol. Expression of PKCß and MET was evaluated in cell lines by immunoblotting. Treatment with SU1174 against MET and enzastaurin against PKCß was performed in H1993 and H358 cell lines, and cell proliferation and downstream signaling (phosphorylation of MET, AKT, FAK, and GSK3ß) were evaluated by immunoblotting. Statistical analysis was performed using SPSS 16.0. Results: Expression of MET positively correlated with lymph node metastases (p=.0004), whereas PKCß showed no correlation (p=0.204). MET and PKCß expression were also strongly correlated (p<0.001). Expression of MET was observed in 5/8 cell lines (H358, H1703, A549, H1993, H2170; absent from H522, H661, or SW1573), whereas PKCß expression was observed in 8/8 cell lines. Cell proliferation was significantly impaired by treatment with SU11274 and enzastaurin, and their effects were synergistic in combination (CI=0.32 and 0.09). Phosphorylation of MET, FAK, AKT, and GSK3ß were strongly inhibited with both agents in combination. Conclusions: Concomitant inhibition of MET and PKCß significantly increased cytotoxicity in vitro against NSCLC, disrupting important downstream signaling pathways. Further evaluation in animal models is warranted.

Effect of the XRCC1 codon 399 polymorphism on the repair of vinyl chloride metabolite-induced DNA damage

Yongliang Li — Wed,7 Oct 2009

Yongliang Li, Changmin Long, George Lin, Marie-Jeanne Marion, Greg Freyer, Regina M Santella, Paul W Brandt-Rauf

Journal of Carcinogenesis 2009 8(1):14-14

Background: Recent epidemiologic evidence suggests that the common polymorphism at amino acid residue 399 of the x-ray cross complementing-1 (XRCC1) protein, a key component of the base excision repair (BER) pathway for DNA damage, plays a significant role in the genetic variability of individuals in terms of the mutagenic damage they experience following exposure to the carcinogen vinyl chloride (VC). The aim of this study was to provide support for the biological plausibility of these epidemiologic observations with experimental data derived from cell lines in culture from individuals who were either homozygous wild-type or homozygous variant for this XRCC1 polymorphism following exposure to chloroethylene oxide (CEO), the active metabolite of VC, with measurement of the induced etheno-DNA adducts before and after repair. Materials and Methods: Immortalized lymphoblast cell lines from seven VC workers (four homozygous wild-type and three homozygous variant for the 399 XRCC1 polymorphism) were exposed to CEO, and etheno-adenosine (εA) adduct levels were determined by enzyme-linked immunosorbent assay (ELISA) pre-exposure and at 0, 4, 8 and 24 h following exposure. Results: The average εA adduct levels were statistically significantly higher in the variant cells compared to the wild-type cells at 8 and 24 h following exposure (P<0.05) with an overall average repair efficiency of 32% in the variant cells compared to 82% in the wild-type cells. Conclusion: These results are consistent with the epidemiologic findings of the types of VC-induced biomarkers observed in exposed individuals and the mutational spectra found in the resultant tumors as well as the key role that BER, especially XRCC1, plays in this carcinogenic pathway.

Gli1 maintains cell survival by up-regulating IGFBP6 and Bcl-2 through promoter regions in parallel manner in pancreatic cancer cells

Xuan-Fu Xu — Thu,3 Sep 2009

Xuan-Fu Xu, Chuan-Yong Guo, Jun Liu, Wen-Juan Yang, Yu-Jing Xia, Ling Xu, Yong-Chun Yu, Xing-Peng Wang

Journal of Carcinogenesis 2009 8(1):13-13

Background: Aberrant activation of Hedgehog (Hh) signaling pathway has been reported to be related to malignant biological behavior of pancreatic cancer but its mechanism is unclear yet. Since IGF pathway and Bcl-2 family are involved in proliferation and apoptosis of pancreatic cancer cells, we hypothesize that they are possibly associated with Hh pathway. Materials and Methods: We studied the relationship of Shh-Gli1 signaling pathway with proliferation and apoptosis of pancreatic cancer cells and the regulation of transcription factor Gli1 to insulin-like growth factor binding protein 6 (IGFBP6) and Bcl-2 genes at the level of transcription. Results: Sonic hedgehog (Shh), Smoothened (Smo), patched and Gli1 were expressed in pancreatic cancer cells. Cyclopamine inhibited cell proliferation at low concentration and induced apoptosis at high concentration. Effect of RNA interference (RNAi) for Gli1 to cell survival is mainly due to proliferation inhibition though involved in apoptosis. The transcription factor Gli1 bound to promoter regions of Bcl-2 and IGFBP6 genes and the levels of IGFBP6, proliferating cell nuclear antigen (PCNA) and Bcl-2 messenger RNA (mRNA) were decreased as well as Gli1 mRNA significantly by cyclopamine or RNAi in cultured pancreatic cancer cells (p < 0.01). Finally PCNA, IGFBP6 and Bcl-2 mRNA were upregulated as well as Shh or Gli1 in pancreatic cancer tissues (p < 0.01). Conclusions: Our study reveals that Gli1 maintained cell survival by binding the promoter regions and facilitating transcription of IGFBP6 and Bcl-2 genes in a parallel manner in pancreatic cancer cells and suggests it may be one of the mechanisms of Shh-Gli1 signaling pathway in pancreatic cancer.

Conformational effects of a common codon 751 polymorphism on the C-terminal domain of the xeroderma pigmentosum D protein

Regina Monaco — Thu,6 Aug 2009

Regina Monaco, Ramon Rosal, Michael A Dolan, Matthew R Pincus, Greg Freyer, Paul W Brandt-Rauf

Journal of Carcinogenesis 2009 8(1):12-12

Aim: The xeroderma pigmentosum D (XPD) protein is a DNA helicase involved in the repair of DNA damage, including nucleotide excision repair (NER) and transcription-coupled repair (TCR). The C-terminal domain of XPD has been implicated in interactions with other components of the TFIIH complex, and it is also the site of a common genetic polymorphism in XPD at amino acid residue 751 (Lys->Gln). Some evidence suggests that this polymorphism may alter DNA repair capacity and increase cancer risk. The aim of this study was to investigate whether these effects could be attributable to conformational changes in XPD induced by the polymorphism. Materials and Methods: Molecular dynamics techniques were used to predict the structure of the wild-type and polymorphic forms of the C-terminal domain of XPD and differences in structure produced by the polymorphic substitution were determined. Results: The results indicate that, although the general configuration of both proteins is similar, the substitution produces a significant conformational change immediately N-terminal to the site of the polymorphism. Conclusion: These results provide support for the hypothesis that this polymorphism in XPD could affect DNA repair capability, and hence cancer risk, by altering the structure of the C-terminal domain.

In vivo effect of an luteinizing hormone-releasing hormone analog on vascular endothelial growth factor and epidermal growth factor receptor expression in mammary tumors

Ana Isabel Flores — Tue,2 Jun 2009

Ana Isabel Flores, Fernando Bedoya, Montserrat Grau, Rafael Enriquez de Salamanca, Irene Vegh

Journal of Carcinogenesis 2009 8(1):11-11

Background: The hypothalamic luteinizing hormone-releasing hormone (LHRH) is well known for its role in the control of pituitary gonadotropin secretion and it has demonstrated a direct antiproliferative effect on some cancer cell lines of LHRH and its synthetic analogs. The study was designed to assess whether administration of the LHRH analog (goserelin) has any effect on the expression of the vascular endothelial growth factor (VEGF) and the epidermal growth factor receptor (EGFR) in rats with N-nitroso-N-methylurea (NMU)-induced-mammary tumors " in vivo". Materials and Methods: The animals with tumors were assessed after acute or chronic treatment with goserelin, and in all the animals VEGF and EGFR expression was examined both in plasma and tumor homogenates by enzyme immunoassay. Results: The basal plasma values of VEGF were lower in the healthy control group than in rats with NMU-induced tumors ( P = 0.025). Following acute treatment with goserelin, VEGF expression in plasma increased above basal levels after 60 min ( P = 0.05) and dropped during chronic treatment. Likewise, in the tumor homogenate the mean VEGF expression was higher at 60 min post-goserelin administration than the basal levels, although VEGF expression then diminished at 90 min. Plasma EGFR expression was higher in rats with NMU-induced tumors than in healthy controls ( P < 0.01). Conclusions: The results allow us to conclude that goserelin may exert a short-term stimulatory effect on the release of VEGF, as well as a long-term inhibitory effect on VEGF but not EGFR expression.

Protein expression analysis of inflammation-related colon carcinogenesis

Yumiko Yasui — Tue,2 Jun 2009

Yumiko Yasui, Takuji Tanaka

Journal of Carcinogenesis 2009 8(1):10-10

Background: Chronic inflammation is a risk factor for colorectal cancer (CRC) development. The aim of this study was to determine the differences in protein expression between CRC and the surrounding nontumorous colonic tissues in the mice that received azoxymethane (AOM) and dextran sodium sulfate (DSS) using a proteomic analysis. Materials and Methods: Male ICR mice were given a single intraperitoneal injection of AOM (10 mg/kg body weight), followed by 2% (w/v) DSS in their drinking water for seven days, starting one week after the AOM injection. Colonic adenocarcinoma developed after 20 weeks and a proteomics analysis based on two-dimensional gel electrophoresis and ultraflex TOF/TOF mass spectrometry was conducted in the cancerous and nontumorous tissue specimens. Results: The proteomic analysis revealed 21 differentially expressed proteins in the cancerous tissues in comparison to the nontumorous tissues. There were five markedly increased proteins (beta-tropomyosin, tropomyosin 1 alpha isoform b, S100 calcium binding protein A9, and an unknown protein) and 16 markedly decreased proteins (Car1 proteins, selenium-binding protein 1, HMG-CoA synthase, thioredoxin 1, 1 Cys peroxiredoxin protein 2, Fcgbp protein, Cytochrome c oxidase, subunit Va, ETHE1 protein, and 7 unknown proteins). Conclusions: There were 21 differentially expressed proteins in the cancerous tissues of the mice that received AOM and DSS. Their functions include metabolism, the antioxidant system, oxidative stress, mucin production, and inflammation. These findings may provide new insights into the mechanisms of inflammation-related colon carcinogenesis and the establishment of novel therapies and preventative strategies to treat carcinogenesis in the inflamed colon.

d -Limonene sensitizes docetaxel-induced cytotoxicity in human prostate cancer cells: Generation of reactive oxygen species and induction of apoptosis

Thangaiyan Rabi — Thu,21 May 2009

Thangaiyan Rabi, Anupam Bishayee

Journal of Carcinogenesis 2009 8(1):9-9

Background: Clinical trials have shown that docetaxel combined with other novel agents can improve the survival of androgen-independent prostate cancer patients. d -Limonene, a non-nutrient dietary component, has been found to inhibit various cancer cell growths without toxicity. We sought to characterize whether a non-toxic dose of d -limonene may enhance tumor response to docetaxel in an in vitro model of metastatic prostate cancer. Materials and Methods: Human prostate carcinoma DU-145 and normal prostate epithelial PZ-HPV-7 cells were treated with various concentrations of d -limonene, docetaxel or a combination of both, and cell viability was determined by MTT assay. Intracellular reactive oxygen species (ROS), reduced glutathione (GSH) and caspase activity were measured. Apoptosis and apoptosis-related proteins were studied by enzyme-linked immunosorbent assay and Western blotting, respectively. Results: d -Limonene and docetaxel in combination significantly enhanced the cytotoxicity to DU-145 cells than PZ-HPV-7 cells. Exposure of DU-145 cells to a combined d -limonene and docetaxel resulted in higher ROS generation, depletion of GSH, accompanied by increased caspase activity than docetaxel alone. It also triggered a series of effects involving cytochrome c , cleavages of caspase-9, 3 and poly (ADP-ribose) polymerase, and a shift in Bad:Bcl-xL ratio in favor of apoptosis. Apoptotic effect was significantly blocked on pretreatment with N -acetylcystein, indicating that antitumor effect is initiated by ROS generation, and caspase cascades contribute to the cell death. Conclusion: Our results show, for the first time, that d -limonene enhanced the antitumor effect of docetaxel against prostate cancer cells without being toxic to normal prostate epithelial cells. The combined beneficial effect could be through the modulation of proteins involved in mitochondrial pathway of apoptosis. d -Limonene could be used as a potent non-toxic agent to improve the treatment outcome of hormone-refractory prostate cancer with docetaxel.

p53 regulates mtDNA copy number and mitocheckpoint pathway

Mariola Kulawiec — Wed,6 May 2009

Mariola Kulawiec, Vanniarajan Ayyasamy, Keshav K Singh

Journal of Carcinogenesis 2009 8(1):8-8

Background: We previously hypothesized a role for mitochondria damage checkpoint (mito-checkpoint) in maintaining the mitochondrial integrity of cells. Consistent with this hypothesis, defects in mitochondria have been demonstrated to cause genetic and epigenetic changes in the nuclear DNA, resistance to cell-death and tumorigenesis. In this paper, we describe that defects in mitochondria arising from the inhibition of mitochondrial oxidative phosphorylation (mtOXPHOS) induce cell cycle arrest, a response similar to the DNA damage checkpoint response. Materials and Methods: Primary mouse embryonic fibroblasts obtained from p53 wild-type and p53-deficient mouse embryos (p53 -/-) were treated with inhibitors of electron transport chain and cell cycle analysis, ROS production, mitochondrial content analysis and immunoblotting was performed. The expression of p53R2 was also measured by real time quantitative PCR. Results: We determined that, while p53 +/+ cells arrest in the cell cycle, p53 -/- cells continued to divide after exposure to mitochondrial inhibitors, showing that p53 plays an important role in the S-phase delay in the cell cycle. p53 is translocated to mitochondria after mtOXPHOS inhibition. Our study also revealed that p53-dependent induction of reactive oxygen species acts as a major signal triggering a mito-checkpoint response. Furthermore our study revealed that loss of p53 results in down regulation of p53R2 that contributes to depletion of mtDNA in primary MEF cells. Conclusions: Our study suggests that p53 1) functions as mito-checkpoint protein and 2) regulates mtDNA copy number and mitochondrial biogenesis. We describe a conceptual organization of the mito-checkpoint pathway in which identified roles of p53 in mitochondria are incorporated.

Helicobacter pylori induces cancer cell motility independent of the c-Met receptor

Jared L Snider — Wed,6 May 2009

Jared L Snider, James A Cardelli

Journal of Carcinogenesis 2009 8(1):7-7

Background: The hepatocyte growth factor (HGF) receptor, c-Met, is strongly implicated in late-stage cancer progression and poor patient prognosis. The stomach pathogen, Helicobacter pylori ( H. pylori ), was recently proposed to stimulate c-Met phosphorylation dependent upon interaction of c-Met with the bacterial CagA protein required for H. pylori -induced cancer cell motility and invasion. Materials and Methods: In this report, we employed short hairpin RNA (shRNA), western blot analysis using antibodies recognizing phosphorylation at discrete c-Met residues, and immunofluorescence microscopy to investigate the CagA-c-Met interaction. Results: The data showed that shRNA-mediated c-Met knockdown did not reduce H. pylori -induced cell motility, suggesting that c-Met was not required for motility. Surprisingly, c-Met knockdown did not reduce the level of an H. pylori -induced protein recognized by a phospho-c-Met antibody. This 125 kD protein was 10 kD smaller than c-Met, suggesting that H. pylori did not phosphorylate c-Met but cross-reacted with another protein. This hypothesis was confirmed when c-Met phosphorylation inhibitors did not lower the levels of the bacteria-induced 125 kD protein, and c-Met immunoprecipitation (IP) did not detect this 125 kD protein from H. pylori -treated lysates. This protein was identified as a product of antibody cross reactivity with phosphorylated CagA. We also confirmed that CagA interacts with c-Met, but this interaction may have caused previous authors to misinterpret phosphorylated CagA as c-Met phosphorylation. Finally, pretreatment with the proteasomal inhibitor, lactacystin, caused prolonged HGF-induced c-Met phosphorylation and facilitated a CagA-negative H. pylori to stimulate AGS cell motility, suggesting that sustained c-Met phosphorylation compensates for the loss of CagA-dependent signaling. Conclusions: These data demonstrate that H. pylori stimulates cancer cell motility independent of the c-Met receptor. We further hypothesize that although H. pylori does not target c-Met, the bacteria may still utilize c-Met effector signaling to stimulate CagA-independent cancer cell motility, which may provide a further mechanism of H. pylori -dependent gastric cancer progression.

Identification of possible genetic alterations in the breast cancer cell line MCF-7 using high-density SNP genotyping microarray

Hui-Yun Wang — Wed,6 May 2009

Hui-Yun Wang, Danielle Greenawalt, Xiangfeng Cui, Irina V Tereshchenko, Minjie Luo, Qifeng Yang, Marco A Azaro, Guohong Hu, Yi Chu, James Y Li, Li Shen, Yong Lin, Lianjun Zhang, Honghua Li

Journal of Carcinogenesis 2009 8(1):6-6

Context: Cancer cell lines are used extensively in various research. Knowledge of genetic alterations in these lines is important for understanding mechanisms underlying their biology. However, since paired normal tissues are usually unavailable for comparison, precisely determining genetic alterations in cancer cell lines is difficult. To address this issue, a highly efficient and reliable method is developed. Aims: Establishing a highly efficient and reliable experimental system for genetic profiling of cell lines. Materials and Methods: A widely used breast cancer cell line, MCF-7, was genetically profiled with 4,396 single nucleotide polymorphisms (SNPs) spanning 11 whole chromosomes and two other small regions using a newly developed high-throughput multiplex genotyping approach. Results: The fractions of homozygous SNPs in MCF-7 (13.3%) were significantly lower than those in the control cell line and in 24 normal human individuals (25.1% and 27.4%, respectively). Homozygous SNPs in MCF-7 were found in clusters. The sizes of these clusters were significantly larger than the expected based on random allelic combination. Fourteen such regions were found on chromosomes 1p, 1q, 2q, 6q, 13, 15q, 16q, 17q and 18p in MCF-7 and two in the small regions. Conclusions: These results are generally concordant with those obtained using different approaches but are better in defining their chromosomal positions. The used approach provides a reliable way to detecting possible genetic alterations in cancer cell lines without paired normal tissues.

Colorectal carcinogenesis: Review of human and experimental animal studies

Takuji Tanaka — Thu,26 Mar 2009

Takuji Tanaka

Journal of Carcinogenesis 2009 8(1):5-5

This review gives a comprehensive overview of cancer development and links it to the current understanding of tumorigenesis and malignant progression in colorectal cancer. The focus is on human and murine colorectal carcinogenesis and the histogenesis of this malignant disorder. A summary of a model of colitis-associated colon tumorigenesis (an AOM/DSS model) will also be presented. The earliest phases of colorectal oncogenesis occur in the normal mucosa, with a disorder of cell replication. The large majority of colorectal malignancies develop from an adenomatous polyp (adenoma). These can be defined as well-demarcated masses of epithelial dysplasia, with uncontrolled crypt cell proliferation. When neoplastic cells pass through the muscularis mucosa and infiltrate the submucosa, they are malignant. Carcinomas usually originate from pre-existing adenomas, but this does not imply that all polyps undergo malignant changes and does not exclude de novo oncogenesis. Besides adenomas, there are other types of pre-neoplasia, which include hyperplastic polyps, serrated adenomas, flat adenomas and dysplasia that occurs in the inflamed colon in associated with inflammatory bowel disease. Colorectal neoplasms cover a wide range of pre-malignant and malignant lesions, many of which can easily be removed during endoscopy if they are small. Colorectal neoplasms and/or pre-neoplasms can be prevented by interfering with the various steps of oncogenesis, which begins with uncontrolled epithelial cell replication, continues with the formation of adenomas and eventually evolves into malignancy. The knowledge described herein will help to reduce and prevent this malignancy, which is one of the most frequent neoplasms in some Western and developed countries.

Colon cancer awareness for prevention: Call for global initiatives

Gopala Kovvali — Fri,6 Mar 2009

Gopala Kovvali

Journal of Carcinogenesis 2009 8(1):4-4

Evaluation of the expression of integrins and cell adhesion molecules through tissue microarray in lymph node metastases of prostate cancer

Jose Pontes-Junior — Wed,25 Feb 2009

Jose Pontes-Junior, Sabrina Thalita Reis, Marcos Dall'Oglio, Luis Carlos Neves de Oliveira, Jose Cury, Paulo Afonso Carvalho, Leopoldo Alves Ribeiro-Filho, Katia Ramos Moreira Leite, Miguel Srougi

Journal of Carcinogenesis 2009 8(1):3-3

Background: Integrins and adhesion molecules are responsible for the maintenance of the epithelial phenotype. Cell culture studies have reported the correlation between adhesion molecule expression and prostate carcinoma, but their role in the metastatic process is not yet known. Our aim is to study the expression profiles of these molecules and evaluate their association with the metastatic behavior of prostate adenocarcinoma. Materials and Methods: A Tissue Microarray containing two samples from 19 primary tumors and one from their corresponding lymph node metastases was constructed and subjected to immunohistochemical analysis of the expression of integrins, E-cadherin and β and γ-catenins. Within each case, paired analyses were also performed to evaluate gains or losses in metastasis compared to its primary tumor. Results: The expression of av, αvβ 3, α2β 1 and γ-catenin were abnormal in almost every case. Marked loss of E-cadherin and β 4 integrin was found in primary and metastatic lesions. β -catenin was normal in all primary cases and in 94% of metastases. a6 was normal in all primary tumors and metastases. α3 and α3β 1 were normal in 32% of primary cases and in 53% and 6% of metastases, respectively. In paired analyses, loss of E-cadherin, β 4, αv, α3β 1 and αvβ 3 was found in 65%, 71%, 59%, 53% and 47% of patients, respectively. Catenins and α2β 1 showed maintenance of expression in most of the cases. Conclusions: In this preliminary study we have shown that the loss of cell adhesion molecules can be considered a characteristic of the metastatic phenotype in prostate cancer. Larger series should be evaluated in order to confirm our findings.

The p53-induced Siva-1 plays a significant role in cisplatin-mediated apoptosis

John L Barkinge — Sat,7 Feb 2009

John L Barkinge, Radhika Gudi, Hawkins Sarah, Fei Chu, Alip Borthakur, Bellur S Prabhakar, Kanteti V.S Prasad

Journal of Carcinogenesis 2009 8(1):2-2

Background: The pro-apoptotic protein Siva-1 functions in both extrinsic and intrinsic cell death signaling; however, the exact contribution of the endogenous Siva-1 to DNA damage-induced apoptosis is unclear. Using cisplatin, a chemotherapeutic drug, to induce DNA damage and cell death, we determined the role of Siva-1. Methods: Cisplatin treated HCT116 colorectal carcinoma cells (p53+/+ and -/-) were used in the study. With the help of recombinant lentivirus that can express siSiva (siRNA that specifically targets Siva-1), we also generated Siva-1 knockdown HCT116 cells. Apoptosis was determined by tetramethyl rhodamine methyl ester (TMRM) staining and propidium iodide (PI) staining. Results: Treatment with cisplatin induced Siva-1 expression in a p53 dependent manner. In Siva-1 knockdown p53+/+ HCT116 colorectal carcinoma cells, loss of Siva-1 expression conferred significant resistance to cisplatin-induced apoptosis. Although Siva-1 levels were positively regulated by p53, Siva-1-induced apoptosis did not require p53. Despite the fact that Siva-1 lacks even a minimal BH3 domain, similar to other proapoptotic Bcl2 family members induced by p53, we showed that Siva-1 mediated apoptosis is characterized by Bax oligomerization and cytochrome c leakage from mitochondria. The putative amphipathic helical region in Siva-1 (SAH) appeared to function analogously to a BH3 domain. Conclusion: The p53 induced Siva-1 is one of the effector molecules, which plays a significant role in DNA damage-induced cell death.

Can 2009 herald a new era in preventing cervical cancers?

Bernice Robinson-Bennett — Fri,30 Jan 2009

Bernice Robinson-Bennett

Journal of Carcinogenesis 2009 8(1):1-1

Synergism of EGFR and c-Met pathways, cross-talk and inhibition, in non-small cell lung cancer

Neelu Puri — Fri,5 Dec 2008

Neelu Puri, Ravi Salgia

Journal of Carcinogenesis 2008 7(1):9-9

Background: c-Met and EGFR receptors are widely expressed on cancer cells; they are implicated in the development and progression of cancer through a plethora of effects on cell cycle progression, apoptosis, motility and metastasis and are potential targets for combination therapy. EGFR receptor tyrosine kinases are currently being targeted in a number of malignancies. Methods: Apoptosis was studied by FACS analysis using propidium iodide. EGF and HGF signaling intermediates were studied by western blotting. Cell proliferation was determined by MTT assays. Cell motility was done by time lapse confocal microscopy. Results: c-Met and EGFR were both expressed in A549, H1838, H2170, SW900, SW1573, H358, SKLU-1, and H1993 non small cell lung cancer (NSCLC) cell lines. Both EGF and HGF at 100 ng/ml in medium showed a synergistic effect on cell proliferation at 48-72 h as seen by a proliferation assay in A549, H1838, and SKMES cells. In A549 and H1838 cell lines, HGF (40 ng/ml) and EGF (5 ng/ml) induced synergistic phosphorylation on c-Met (Tyr 1003/1230/1234/1235). Additionally, synergistic phosphorylation of Akt (Ser-473) and phospho-ERK1+ERK2 (Thr202/Tyr204) was also seen indicating that EGF and HGF could induce synergistic phosphorylation of important signaling intermediates. Treatment with EGF and HGF at 100 ng/ml for 2 h also leads to an additive effect in inducing cell motility (especially membrane ruffling) in H1993 cells. A novel c-Met small molecule tyrosine kinase inhibitor SU11274 and EGFR tyrosine kinase inhibitors Tyrphostin AG1478 and gefitinib (Iressa) were tested to study their effect in combination on proliferation and apoptosis in lung cancer cells. Interestingly, a synergistic effect on inhibition of cell proliferation was seen in the presence of SU11274 and Tyrphostin AG1478. 0.5 µM Tyrphostin AG1478 and 2 µM SU11274 inhibited growth by 21% and 25%, respectively; a combination of both tyrosine kinase inhibitors inhibited growth by 65%. Interestingly, EGFR inhibitor (gefitinib, Iressa) and c-Met inhibitor (SU11274) also had a synergistic effect on apoptosis in H358 cells. Conclusion: There was a synergistic effect of EGF and HGF on proliferation, downstream activation of signal transduction and an additive effect seen on motility. These studies show that a combination of HGF and EGF tyrosine kinase inhibitors on NSCLC, could potentially be targeted in a synergistic fashion.

High prevalence of HER-2/neu overexpression in female breast cancer among an Iraqi population exposed to depleted uranium

Esraa A AL-Dujaily — Mon,10 Nov 2008

Esraa A AL-Dujaily, Asad A Al-Janabi, Tomasz Pierscionek, Akeel A Yasseen

Journal of Carcinogenesis 2008 7(1):8-8

Background: This study aimed to estimate the rate of HER-2/neu (c-erbB2) immunohistochemical overexpression in different histological types of breast cancer found in the middle Euphrates region of Iraq, a region that was exposed to high levels of depleted uranium. HER-2/neu (c-erbB2) overexpression was correlated with common clinicopathological parameters such as age, grade, stage, tumor size and lymph node involvement to determine if any particular biomarker for exposure to depleted uranium could be found in the tumor samples from this region. Materials and Methods: The present investigation was performed over a period starting from September 2007 to June 2008. Formalin-fixed, paraffin-embedded blocks from 90 patients with breast cancer were included in this study. A group of 25 patients with benign breast lesions (fibroadenoma) was included as a comparative group, and 20 breast tissue sections were used as controls. Labeled streptavidin-biotin (LSAB) complex method was employed for immunohistochemical detection of HER-2/neu. Results: HER-2/neu immuno-expression was positive in 67.8% of breast cancer, while it was negative in all benign breast lesions (fibroadenoma) ( P < 0.05). HER-2/neu immunostaining was significantly associated with histological type and recurrence of breast cancer ( P < 0.05). It was positively correlated with tumor grade, but this finding was not significant ( P > 0.05). Conclusion: Based upon the findings of this study, it can be concluded that HER-2/neu overexpression plays an important role in the pathogenesis of breast cancer and is associated with a worse prognosis. The findings indicate that in regions exposed to high levels of depleted uranium, HER-2/neu overexpression is high, but its correlation with age, grade, stage, tumor size, and lymph node involvement is similar to studies that have been conducted on populations not exposed to depleted uranium.

Stamp out lung cancer

Ravi Salgia — Sat,8 Nov 2008

Ravi Salgia

Journal of Carcinogenesis 2008 7(1):7-7

Does GATA3 act in tissue-specific pathways? A meta-analysis-based approach

Brian J Wilson — Wed,1 Oct 2008

Brian J Wilson

Journal of Carcinogenesis 2008 7(1):6-6

The GATA3 transcription factor is expressed in many tissues such as the immune system, kidney, brain, endometrium, and mammary epithelial cells. As such it must co-ordinate a diverse transcriptional program to achieve specific outcomes in different tissues. One of the most interesting questions raised is whether GATA3 will be involved in the same pathways in every tissue or will be involved in distinct regulatory networks within different tissue types? While previous studies may imply the latter, with some known targets of GATA3 perhaps being specific to cell-type or tissue-type, the question has not been systematically addressed until now. With the advent of techniques such as co-expression meta-analysis a better understanding of the pathway partners of GATA3 can be obtained and specifically the partners within different tissue types can be found, yielding leads for future studies. Here, a recent technique of meta-analysis from the Oncomine database has been employed to probe this very question. Data obtained implies that GATA3 is involved in distinct pathways in different tissue types.

Polydimethylsiloxane: An effective immune adjuvant and slow-release cytokine medium for local cancer treatment

Beniamino Palmieri — Thu,25 Sep 2008

Beniamino Palmieri, Farid Saleh, Giorgia Benuzzi, Alyaa Mousa, Ali Shamseddine, Khalid Al-Sebeih

Journal of Carcinogenesis 2008 7(1):5-5

Background and Aim: Silicone oil or gel has well-defined chemotactic properties on monocytes and lymphocytes in vivo . It results in fibrotic reaction when spread into the human tissues either incidentally or purposely and can slowly release any physically-enclosed lyophilized compounds due to its viscosity. Our aim is to investigate whether polydimethylsiloxane could be considered as an effective medium in the local treatment of cancer. Materials and Methods: Our study was conducted between January 2004 and December 2006 on 15 patients with various types of cancer. The criteria for selection included patients with locally-advanced tumor that was rapidly growing and life threatening and those who had poor quality of life and general wellbeing. The patients were already discharged from the cancer centre before joining the study, after they had already received their chemoradiation protocol. Once a week for one month, different areas of the tumor were injected with 0.25 ml of polydimethylsiloxane medical grade (viscosity: 350 centistokes at 30°C), mixed with 300,000 units of lyophilized human IL-2. Tumor biopsies were taken before the study was started and one week after the last injection for the histopathological analysis of the percentage of severe inflammatory reaction using an image analysis system. CT scans of the tumor were taken before the injection cycle was started and one week after the last injection in order to determine the percentage change in the size of the tumor. The quality of life and general wellbeing of the patients was assessed at the beginning of the stud, and one week after the study was over by using the Karnofsky performance test. Results: Our treatment was well tolerated by the patients. They had a significant improvement in their quality of life and general well being ( p = 0.0005). The prognosis of the patients before the beginning of the study ranged between 1 and 6 months, while their overall survival after treatment was between 2 and 12 months, with three patients still remaining alive. A significant decrease in the tumor size was observed at the end of the study in 12 patients ( p < 0.0001). Such a decrease was associated with a significant increase in the percentage of the tumor containing a severe immune reaction ( p < 0.0001). A significant correlation was found between the percentage reduction in tumor size and the percentage of tumor immune reaction (r 2 = 0.968; p < 0.0001). Conclusion: Polydimethylsiloxane could be used as an effective cytokine medium in the local treatment of cancer. When injected inside the tumor, it is capable of creating and modulating an effective, slow and persistent antitumor immune response. Moreover, it is capable of improving the overall survival as well as the quality of life and general well being of the cancer patients.

Retraction: Pathogenesis of malignant pleural mesothelioma and the role of environmental and genetic factors

Shoshana J Weiner — Fri,8 Aug 2008

Shoshana J Weiner, Siyamek Neragi-Miandoab

Journal of Carcinogenesis 2008 7(1):4-4

Pathogenesis of malignant pleural mesothelioma and the role of environmental and genetic factors

Shoshana J Weiner — Mon,28 Jul 2008

Shoshana J Weiner, Siyamek Neragi-Miandoab

Journal of Carcinogenesis 2008 7(1):3-3

Malignant pleural mesothelioma (MPM) is a rare, aggressive tumor for which no effective therapy exists despite the discovery of many possible molecular and genetic targets. Many risk factors for MPM development have been recognized including environmental exposures, genetic susceptibility, viral contamination, and radiation. However, the late stage of MPM diagnosis and the long latency that exists between some exposures and diagnosis have made it difficult to comprehensively evaluate the role of risk factors and their downstream molecular effects. In this review, we discuss the current molecular and genetic contributors in MPM pathogenesis and the risk factors associated with these carcinogenic processes.

Implications of tyrosine phosphoproteomics in cervical carcinogenesis

Bernice L Robinson-Bennett — Thu,17 Jul 2008

Bernice L Robinson-Bennett, James DeFord, Concepcion Diaz-Arrastia, Lyuba Levine, Hui-Qui Wang, Edward V Hannigan, John Papaconstantinou

Journal of Carcinogenesis 2008 7(1):2-2

Background: Worldwide cervical cancer remains a leading cause of mortality from gynecologic malignancies. The link between cervical cancer and persistent infection with HPV has been established. At a molecular level little is known about the transition from the precancerous state to invasive cancer. To elucidate this process, cervical biopsies from human specimens were obtained from precancerous state to stage III disease. Methods: Cervical biopsies were obtained from patients with a diagnosis of cervical cancer undergoing definitive surgery or staging operation. Biopsies were obtained from patients with precancerous lesions at the time of their excisional procedure. Control samples were obtained from patients undergoing hysterectomy for benign conditions such as fibroids. Samples were subjected to proteomic profiling using two dimensional gel electrophoresis with subsequent trypsin digestion followed by MALDI-TOF protein identification. Candidate proteins were then further studied using western blotting, immunoprecipitation and immunohistochemistry. Results: Annexin A1 and DNA-PKcs were found to be differentially expressed. Phosphorylated annexin A1 was up regulated in diseased states in comparison to control and its level was strongly detected in the serum of cervical cancer patients compared to controls. DNA-PKcs was noted to be hyperphosphorylated and fragmented in cancer when compared to controls. By immunohistochemistry annexin A1 was noted in the vascular environment in cancer and certain precancerous samples. Conclusion: This study suggests a probable role for protein tyrosine phosphorylation in cervical carcinogenesis. Annexin A1 and DNA-PK cs may have synergistic effects with HPV infection. Precancerous lesions that may progress to cervical cancer may be differentiated from lesions that will not base on similar immunohistochemical profile to invasive squamous cell carcinoma.

BRAF V600E mutations in malignant melanoma are associated with increased expressions of BAALC

David Schrama — Wed,16 Jul 2008

David Schrama, Gunhild Keller, Roland Houben, Christian G Ziegler, Claudia S Vetter-Kauczok, Selma Ugurel, Jurgen C Becker

Journal of Carcinogenesis 2008 7(1):1-1

Bachground: Activating BRAF mutations are present in approximately 50% of melanomas. Although different downstream target genes of the most common mutant V600E have been identified, the contribution of activating BRAF mutations to malignant transformation needs further clarification. Methods: Microarray gene analysis was performed for human melanoma cell lines harboring BRAF V600E mutations in comparison to cell lines without this mutation. Results: This analysis revealed a more than two fold down-regulation of 43 and an increase of 39 gene products. BAALC ( Brain and acute Leukaemia, cytoplasmatic ) was most prominently regulated, since it was up-regulated in mutated cell lines by a mean of 11.45. Real time PCR analyses with RNA from melanoma cell lines (n = 30) confirmed the BRAF -activation dependent up-regulation of BAALC . Conclusion: BAALC , which has been associated with cell dedifferentiation and migration, may function as a downstream effector of activating BRAF mutations during melanomagenesis.

Comparative evaluation of antiproliferative, antiangiogenic and apoptosis inducing potential of black tea polyphenols in the hamster buccal pouch carcinogenesis model

Paramasivame Vidjaya Letchoumy — Mon,3 Dec 2007

Paramasivame Vidjaya Letchoumy, Kurapathy Venkata Poorna Chandra Mohan, Duvuru Prathiba, Yukihiko Hara, Siddavaram Nagini

Journal of Carcinogenesis 2007 6(1):19-19

Background To evaluate the relative chemopreventive efficacy of two black tea polyphenols, Polyphenon-B [P-B] and BTF-35 on 7,12-dimethylbenz [a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. Methods Hamsters were divided into 6 groups. The right buccal pouches of animals in groups 1-3 were painted with 0.5% of DMBA three times a week for 14 weeks. While hamsters in group 1 received no further treatment, animals in groups 2 and 3 received diet containing 0.05% P-B and BTF-35 respectively, four weeks before DMBA painting that was continued until the end of the experiments. Animals in groups 4 and 5 were given P-B and BTF-35 alone respectively as in groups 2 and 3. Group 6 animals served as the untreated control. All the animals were sacrificed after 18 weeks. The expression of p21, cyclin D1, glutathione S-transferase pi (GST-P), nuclear factor kappa B (NF-κB), Bcl-2, Bax, cytochrome C, caspase-3, caspase-9, poly(ADP-ribose) polymerase (PARP), cytokeratins and vascular endothelial growth factor (VEGF) was analysed by RT-PCR, immunohistochemical and Western blot analyses. Results DMBA treated animals developed buccal pouch carcinomas that displayed increased expression of p21, cyclin D1, GST-P, NF-κB, cytokeratins, VEGF and Bcl-2 with decreased expression of Bax, cytochrome C, caspase-3, caspase-9, and PARP. Dietary administration of both P-B and BTF-35 reduced the incidence of DMBA-induced HBP carcinomas by modulating markers of cell proliferation, cell survival, tumour infiltration, angiogenesis, and apoptosis. Conclusion The results of the present study provide a mechanistic basis for the chemopreventive potential of black tea polyphenols. The greater efficacy of BTF-35 in inhibiting HBP carcinogenesis and modulating multiple molecular targets may have a potential role in the prevention of oral cancer.

Prolactin, TNF alpha and nitric oxide expression in nitroso-N-methylurea-induced-mammary tumours

Irene Vegh — Wed,28 Nov 2007

Irene Vegh, Rafael Enriquez de Salamanca

Journal of Carcinogenesis 2007 6(1):18-18

Background The N-Nitrosomethylurea breast cancer model induced in rats is used for the study of carcinogenesis in mammary cancer, prostate, pancreas, etc. This model is very similar to human neoplastic disease. Methods The present experimental study was designed to assess whether metoclopramide administration has any effect on development of MNU-induced tumours, and evaluate the treatment of goserelin acetate on PRL, TNF alpha and NO expression. NMU was administered to female Wistar rats on 2 occasions (5 mg/100 g body w/rat). PRL and TNF alpha were performed by immune-assay. Nitric Oxide by semi automated-assay and ploidy analyses by flow cytometry. Results The administration of metoclopramide made the induction time shorter and increased the incidence and average of tumours per rat. Tumours development was inhibited by a goserelin chronic administration. The ploidy of adenocarcinoma was polyploid-aneuploid type (average S = 60%). It was higher basal PRL plasma levels in rats with NMU induced tumours than in basal controls without tumour (p < 0.001). The goserelin "in bolus" administration showed maximal inhibition of plasma PRL at 90 min. Plasmatic TNF alpha expression was inhibited at 60 min and also remained inhibited in tissue homogenate post chronic treatment (P < 0.0125). Plasmatic NO expression is higher in rats with induced tumours than healthy controls (P < 0.001). In tissue homogenate NO values were inhibited at 90 min (P < 0.01), as well during chronically goserelin treatment (P < 0.005). Conclusion The increase of blood PRL levels in NMU-induced rats may be an indicator of a poor prognosis of mammary cancer evolution. The metoclopramide administration accelerates tumour growth. However goserelin administration achieves regression in tumour development associated to inhibition PRL, TNF alpha and NO expression.

The effects of a cyclooxygenase-2 (COX-2) expression and inhibition on human uveal melanoma cell proliferation and macrophage nitric oxide production

Jean-Claude Marshall — Tue,27 Nov 2007

Jean-Claude Marshall, Amanda L Caissie, Stephanie R Cruess, Jonathan Cools-Lartigue, Miguel N Burnier

Journal of Carcinogenesis 2007 6(1):17-17

Background Cyclooxygenase-2 (COX-2) expression has previously been identified in uveal melanoma although the biological role of COX-2 in this intraocular malignancy has not been elucidated. This study aimed to investigate the effect of a COX-2 inhibitor on the proliferation rate of human uveal melanoma cells, as well as its effect on the cytotoxic response of macrophages. Methods Human uveal melanoma cell lines were transfected to constitutively express COX-2 and the proliferative rate of these cells using two different methods, with and without the addition of Amfenac, was measured. Nitric oxide production by macrophages was measured after exposure to melanoma-conditioned medium from both groups of cells as well as with and without Amfenac, the active metabolite of Nepafenac. Results Cells transfected to express COX-2 had a higher proliferation rate than those that did not. The addition of Amfenac significantly decreased the proliferation rate of all cell lines. Nitric oxide production by macrophages was inhibited by the addition of melanoma conditioned medium, the addition of Amfenac partially overcame this inhibition. Conclusion Amfenac affected both COX-2 transfected and non-transfected uveal melanoma cells in terms of their proliferation rates as well as their suppressive effects on macrophage cytotoxic activity.

RKIP does not contribute to MAP kinase pathway silencing in the Merkel Cell Carcinoma cell line UISO

Roland Houben — Wed,24 Oct 2007

Roland Houben, Sonja Ortmann, Juergen C Becker

Journal of Carcinogenesis 2007 6(1):16-16

Background The Raf kinase inhibitor protein (RKIP) has been shown to block MAP kinase pathway as well as NFκB signalling. By means of immunohistochemistry, we previously demonstrated that the MAP kinase pathway is virtually inactive in Merkel cell carcinoma (MCC). Similarly to MCC in situ high RKIP expression accompanies absence of ERK phosphorylation in the MCC cell line UISO suggesting that RKIP might be causative for MAP kinase pathway silencing. Methods Applying an siRNA approach RKIP expression was knocked down in UISO cells and a possible influence on MAP kinase pathway activity was assessed by Western blot analysis using phospho-specific antibodies. Moreover, a possible effect of RKIP knock down in UISO cells on proliferation as well as chemosensitivity to cisplatin were examined applying the MTS assay. Results Surprisingly the absence of phosphorylation of the MAP kinases ERK1 and ERK 2 even following growth factor stimulation was not affected by the RKIP knock down indicating that RKIP is not essential for blocking the MAP kinase pathway in the MCC cell line UISO. Moreover, proliferation as well as chemosensitivity towards cisplatin were not altered upon knock down of RKIP.

Distinct evolutionary mechanisms for genomic imbalances in high-risk and low-risk neuroblastomas

David Gisselsson — Wed,26 Sep 2007

David Gisselsson, Gisela Lundberg, Ingrid Ora, Mattias Hoglund

Journal of Carcinogenesis 2007 6(1):15-15

Background Neuroblastoma (NB) is the most common extracranial solid tumour of childhood. Several genomic imbalances correlate to prognosis in NB, with structural rearrangements, including gene amplification, in a near-diploid setting typically signifying high-risk tumours and numerical changes in a near-triploid setting signifying low-risk tumours. Little is known about the temporal sequence in which these imbalances occur during the carcinogenic process. Methods We have reconstructed the appearance of cytogenetic imbalances in 270 NBs by first grouping tumours and imbalances through principal component analysis and then using the number of imbalances in each tumour as an indicator of evolutionary progression. Results Tumours clustered in four sub-groups, dominated respectively by (1) gene amplification in double minute chromosomes and few other aberrations, (2) gene amplification and loss of 1p sequences, (3) loss of 1p and other structural aberrations including gain of 17q, and (4) whole-chromosome gains and losses. Temporal analysis showed that the structural changes in groups 1-3 were acquired in a step-wise fashion, with loss of 1p sequences and the emergence of double minute chromosomes as the earliest cytogenetic events. In contrast, the gains and losses of whole chromosomes in group 4 occurred through multiple simultaneous events leading to a near-triploid chromosome number. Conclusion The finding of different temporal patterns for the acquisition of genomic imbalances in high-risk and low-risk NBs lends strong support to the hypothesis that these tumours are biologically diverse entities, evolving through distinct genetic mechanisms.

The association between paternal prostate cancer and type 2 diabetes

Peter Meyer — Wed,26 Sep 2007

Peter Meyer, Christine Zuern, Norbert Hermanns, Thomas Haak

Journal of Carcinogenesis 2007 6(1):14-14

Objective Increasing evidence indicates that type 2 diabetic patients are at elevated risk for developing different kinds of cancers. However, diabetes mellitus may be a protective factor for prostate cancer since both were found to be negatively associated. Based on the same genetic background, parents of diabetic patients might show similar risks concerning cancers. Research design and methods We conducted a case-control study, where familiy history of 794 type 2 diabetic cases and 775 non-diabetic controls was ascertained. Then, we expanded our study up to 801 type 2 diabetic cases and 1267 non-diabetic controls. Results Concerning the 794 type 2 diabetic patients and 775 controls, we observed that cancer of cervix uteri was elevated among mothers of controls (odds ratio (OR) 0.19; 95% confidence interval (CI) 0.02 to 0.88; p = 0.033). Mothers of diabetic patients showed an increased history of cancers of the liver and biliary tract (OR 5.23; 95% CI 1.87 to 19.9; p = 0.0009) and stomach (OR 3.84; 95% CI 1.47 to 12.4; p = 0.0049). Pancreatic cancers were found to be elevated in fathers of diabetic patients (OR 4.92; 95% CI 1.07 to 46.7; p = 0.039). Most notably, a lower number of prostate cancers was observed in fathers of diabetic patients (OR 0.47; 95% CI 0.22 to 0.94; p = 0.032). Since diabetic patients were 14.3 years older than the controls, higher levels of cancer history among parents of diabetic patients would have been expected. Thus, the observed lower level of history of prostate cancer can be regarded as highly reliable. The analysis of 801 type 2 diabetics and 1267 controls showed that cancer of stomach was elevated among mothers of controls (OR 2.67; p = 0.0106). In addition, stomach cancers were found to be elevated in fathers of diabetic patients (OR 2.10; p = 0.0141). In accordance with the previous investigation, we again obseved a lower number of prostate cancers in fathers of diabetic patients (OR 0.49; p = 0.0279). However, the application of the statistical method of Mantel-Haenszel showed no significant result concerning any of the cancer histories. Conclusion Fathers of patients suffering from type 2 diabetes were diagnosed less frequently with prostate cancer compared to fathers of non-diabetic controls. As first-degree relatives, e.g. diabetic patients and their fathers, share 50% of their genes, it appears plausible that genetic factors may play an important role in the negative association between diabetes and prostate cancer. However, different statistic analyses showed controversial results concerning the effect of type 2 diabetes on prostate cancers.

The role of GSTM1 gene polymorphisms in lung cancer development in Turkish population

Adalet Demir — Wed,26 Sep 2007

Adalet Demir, Sedat Altin, Davut Pehlivan, Mulahim Demir, Fatih Yakar, Ekrem Cengiz Seyhan, Seyyit Ibrahim Dincer

Journal of Carcinogenesis 2007 6(1):13-13

Background Glutathione S-transferase (GSTs) plays an important role in the detoxification of many xenobiotics involved in the etiology of cancer. In different ethnic groups, variations in null allele frequency have been observed. We have investigated GSTM1 gene polymorphisms in healthy subjects and lung cancer patients in the Turkish population and reviewed the control subjects of the studies performed in the Turkish population. Methods Following blood sampling from patients and controls, DNA samples were extracted from the whole blood and were amplified by using polymerase chain reaction (PCR) method in all of the 256 cases, consisting of 102 previously diagnosed with lung cancer and 154 healthy controls. Results The prevalence of GSTM1-null genotype in the lung cancer patients was 49%, compared to 52.6% in the control group (OR = 1.39, 95% CI = 0.70-1.90, p = 0.57). There were also no significant relationships in GSTM1 genotypes among histopathologic types of lung cancers (p > 0.05). The frequency of GSTM1 was found to be 41.2% (n = 1809) when the control subjects of the studies performed in Turkish population were reviewed. Conclusion We have observed that GSTM1 genotype is not an independent risk factor for lung cancer.

Pathobiological features of breast tumours in the State of Kuwait: a comprehensive analysis

Farid Saleh — Mon,24 Sep 2007

Farid Saleh, Suad Abdeen

Journal of Carcinogenesis 2007 6(1):12-12

Background Breast cancer accounts for 30.3% of all cancer types in Kuwaiti women. Death occurs in approximately 43% of these patients. Our goal was to conduct a comprehensive analysis of the pathobiological characteristics of the tumours in an attempt to determine any particular trend that could be present. Methods One hundred and sixty-six cases were included in this study. All the pathology reports and paraffin blocks pertaining to these cases were collected. Four micrometer sections were taken from each block, and immunostaining against Her-2, ER, and PgR was performed. Both the proportion and intensity of immunostaining were scored according to the Allred's method, and typing of the tumour was done according the WHO criteria regarding tumour classification. Grading of invasive carcinomas was done according to the modified Bloom-Richardson-Elston's method, and tumour stage was determined according to the criteria set by the American Joint Committee on Cancer. Results The mean age of the patients below 55 years was 40, as compared to 68 for those above 55 (p < 0.0001). More than half of the cases were in the right breast, and were surgically treated by total mastectomy with axillary clearance. The majority of the tumours had irregular (stellate) margins, was invasive, and had a surrounding breast tissue of adenosis or fibrocystic type. Their mitotic index was 10-20 or >20 with a marked to moderate nuclear pleomorphism. They were mostly grade II or III, sized 2-5 or > 5 cm, had absent or scanty tumour lymphocytes, and were stage II or III. The in situ tumours were mainly ductal carcinoma (DCIS) of which comedo and cribriform were the major histological subtypes. The major histological subtypes of the invasive tumours were ductal-not otherwise specified, lobular, and tubular/cribriform. In this study, we also found a significant (p < 0.05) association between over expression of Her-2, lack of expression of ER and some of the characteristics mentioned above. Conclusion Breast cancer in Kuwait seems to be more aggressive than what is currently seen in Europe, North America, Australia, and parts of Asia. Further investigations regarding the features observed in this study need to be performed.

α2β1 integrin affects metastatic potential of ovarian carcinoma spheroids by supporting disaggregation and proteolysis

Kristy Shield — Thu,14 Jun 2007

Kristy Shield, Clyde Riley, Michael A Quinn, Gregory E Rice, Margaret L Ackland, Nuzhat Ahmed

Journal of Carcinogenesis 2007 6(1):11-11

Background Ovarian cancer is characterized by a wide-spread intra-abdominal metastases which represents a major clinical hurdle in the prognosis and management of the disease. A significant proportion of ovarian cancer cells in peritoneal ascites exist as multicellular aggregates or spheroids. We hypothesize that these cellular aggregates or spheroids are invasive with the capacity to survive and implant on the peritoneal surface. This study was designed to elucidate early inherent mechanism(s) of spheroid survival, growth and disaggregation required for peritoneal metastases Methods In this study, we determined the growth pattern and adhesive capacity of ovarian cancer cell lines (HEY and OVHS1) grown as spheroids, using the well established liquid overlay technique, and compared them to a normal ovarian cell line (IOSE29) and cancer cells grown as a monolayer. The proteolytic capacity of these spheroids was compared with cells grown as a monolayer using a gelatin zymography assay to analyze secreted MMP-2/9 in conditioned serum-free medium. The disaggregation of cancer cell line spheroids was determined on extracellular matrices (ECM) such as laminin (LM), fibronectin (FN) and collagen (CI) and the expression of α2, α3, αv, α6 and β1 interin was determined by flow cytometric analysis. Neutralizing antibodies against α2, β1 subunits and α2β1 integrin was used to inhibit disaggregation as well as activation of MMPs in spheroids. Results We demonstrate that ovarian cancer cell lines grown as spheroids can sustain growth for 10 days while the normal ovarian cell line failed to grow beyond 2 days. Compared to cells grown as a monolayer, cancer cells grown as spheroids demonstrated no change in adhesion for up to 4 days, while IOSE29 cells had a 2-4-fold loss of adhesion within 2 days. Cancer cell spheroids disaggregated on extracellular matrices (ECM) and demonstrated enhanced expression of secreted pro-MMP2 as well as activated MMP2/MMP9 with no such activation of MMP's observed in monolayer cells. Flow cytometric analysis demonstrated enhanced expression of α2 and diminution of α6 integrin subunits in spheroids versus monolayer cells. No change in the expression of α3, αv and β1 subunits was evident. Conversely, except for αv integrin, a 1.5-7.5-fold decrease in α2, α3, α6 and β1 integrin subunit expression was observed in IOSE29 cells within 2 days. Neutralizing antibodies against α2, β1 subunits and α2β1 integrin inhibited disaggregation as well as activation of MMPs in spheroids. Conclusion Our results suggest that enhanced expression of α2β1 integrin may influence spheroid disaggregation and proteolysis responsible for the peritoneal dissemination of ovarian carcinoma. This may indicate a new therapeutic target for the suppression of the peritoneal metastasis associated with advanced ovarian carcinomas.

Mucin glycoarray in gastric and gallbladder epithelia

Iniya Meenakshi Ganesh — Tue,12 Jun 2007

Iniya Meenakshi Ganesh, Duraibabu Subramani, Devaraj Halagowder

Journal of Carcinogenesis 2007 6(1):10-10

Background Mucins are critical cytoprotective glycoproteins and alterations of epithelial gastric mucins have been described in different pathological conditions. The purpose of the present study was to evaluate the putative usefulness of mucins in understanding the progression of gastric cancer and gallstone formation in a better perspective. Methods Formalin-fixed paraffin-embedded gastric biopsy specimens and surgically resected gallbladder tissue samples were sectioned. Alcian Blue (AB) staining was performed to identify sialomucins (staining blue at pH 2.5) and sulfomucins (staining brown at pH 1.0) and then Periodic acid-Schiff's (PAS) staining to visualize the neutral mucins (staining magenta). Results In normal gastric and gallbladder mucosae, we found that neutral mucins were predominant, whereas in intestinal metaplasia, gastric carcinoma and stone-containing gallbladder, a significant increase of acidic mucins was found. Conclusion We suggest that the sulfomucins have a greater role in gallstone formation than the neutral mucins and also that the sialomucins and sulfomucins play an important role in cancer progression and metastasis. Our results challenge the glycobiologists to delve deeper in elucidating the role of mucins in gastric malignancy and in gallstone formation.

Methylation of the BIN1 gene promoter CpG island associated with breast and prostate cancer

Ekaterina B Kuznetsova — Fri,4 May 2007

Ekaterina B Kuznetsova, Tatiana V Kekeeva, Sergei S Larin, Valeria V Zemlyakova, Anastasiya V Khomyakova, Olga V BabenkBabenko, Marina V Nemtsova, Dmitry V Zaletayev, Vladimir V Strelnikov

Journal of Carcinogenesis 2007 6(1):9-9

Background Loss of BIN1 tumor suppressor expression is abundant in human cancer and its frequency exceeds that of genetic alterations, suggesting the role of epigenetic regulators (DNA methylation). BIN1 re-expression in the DU145 prostate cancer cell line after 5-aza-2'-deoxycytidine treatment was recently reported but no methylation of the BIN1 promoter CpG island was found in DU145. Methods Methylation-sensitive arbitrarily-primed PCR was used to detect genomic loci abnormally methylated in breast cancer. BIN1 CpG island fragment was identified among the differentially methylated loci as a result of direct sequencing of the methylation-sensitive arbitrarily-primed PCR product and subsequent BLAST alliance. BIN1 CpG island cancer related methylation in breast and prostate cancers was confirmed by bisulphite sequencing and its methylation frequency was evaluated by methylation sensitive PCR. Loss of heterozygosity analysis of the BIN1 region was performed with two introgenic and one closely adjacent extragenic microsatellite markers. BIN1 expression was evaluated by real-time RT-PCR. Results We have identified a 3'-part of BIN1 promoter CpG island among the genomic loci abnormally methylated in breast cancer. The fragment proved to be methylated in 18/99 (18%) and 4/46 (9%) breast and prostate tumors, correspondingly, as well as in MCF7 and T47D breast cancer cell lines, but was never methylated in normal tissues and lymphocytes as well as in DU145 and LNCaP prostate cancer cell lines. The 5'-part of the CpG island revealed no methylation in all samples tested. BIN1 expression losses were detected in MCF7 and T47D cells and were characteristic of primary breast tumors (10/13; 77%), while loss of heterozygosity was a rare event in tissue samples (2/22 informative cases; 9%) and was ruled out for MCF7. Conclusion BIN1 promoter CpG island is composed of two parts differing drastically in the methylation patterns in cancer. This appears to be a common feature of cancer related genes and demands further functional significance exploration. Although we have found no evidence of the functional role of such a non-core methylation in BIN1 expression regulation, our data do not altogether rule this possibility out.

Metastatic progression and gene expression between breast cancer cell lines from African American and Caucasian women

Haile F Yancy — Tue,1 May 2007

Haile F Yancy, Jacquline A Mason, Sharla Peters, Charles E Thompson, George K Littleton, Marti Jett, Agnes A Day

Journal of Carcinogenesis 2007 6(1):8-8

African American (AA) women have a lower overall incidence of breast cancer than do Caucasian (CAU) women, but a higher overall mortality. Little is known as to why the incidence of breast cancer is lower yet mortality is higher in AA women. Many studies speculate that this is only a socio-economical problem. This investigation suggests the possibility that molecular mechanisms contribute to the increased mortality of AA women with breast cancer. This study investigates the expression of 14 genes which have been shown to play a role in cancer metastasis. Cell lines derived from AA and CAU patients were analyzed to demonstrate alterations in the transcription of genes known to be involved in cancer and the metastatic process. Total RNA was isolated from cell lines and analyzed by RT-PCR analysis. Differential expression of the 14 targeted genes between a spectrum model (6 breast cancer cell lines and 2 non-cancer breast cell lines) and a metastasis model (12 metastatic breast cancer cell lines) were demonstrated. Additionally, an in vitro comparison of the expression established differences in 5 of the 14 biomarker genes between African American and Caucasian breast cell lines. Results from this study indicates that altered expression of the genes Atp1b1, CARD 10, KLF4, Spint2, and Acly may play a role in the aggressive phenotype seen in breast cancer in African American women.

Where did the super-small sized large bowel advanced cancer come from?

Ryo Wada — Mon,30 Apr 2007

Ryo Wada, Koichi Sato, Takafumi Ichida, Hiroshi Maekawa, Kaoru Ogawa, Takeo Maekawa

Journal of Carcinogenesis 2007 6(1):7-7

Our study suggested that the super-small sized (less than 15 mm in maximum diameter) large bowel advanced cancers, which were sometimes found, were derived from the superficial depressed-type or flat elevation-type of the colorectal early cancers, not polyp-type of those.

Immunohistochemical expression of melan-A and tyrosinase in uveal melanoma

Bruno F Fernandes — Fri,20 Apr 2007

Bruno F Fernandes, Alexandre N Odashiro, Vinicius S Saraiva, Patrick Logan, Emilia Antecka, Miguel N Burnier Jr

Journal of Carcinogenesis 2007 6(1):6-6

Background Melan-A and tyrosinase are new immunohistochemical markers that can be used in the diagnosis of melanocytic lesions. The aim of this study was to investigate the correlation between radiotherapy or clinicohistopathological parameters and the expression of melan-A and tyrosinase in uveal melanoma. Methods Thirty-six enucleated cases of uveal melanoma were studied. The formalin-fixed, paraffin-embedded specimens were immunostained with monoclonal antibodies against melan-A and tyrosinase. The samples were classified as either positive or negative. The chi-square or the Student-t tests were used to test for the correlation of the expression rates of melan-A and tyrosinase with clinico-pathological parameters. Results Melan-A and tyrosinase were positive in 33 (91.7%) and 35 (97.2%) of the specimens, respectively. There was no significant association between the expression of melan-A or tyrosinase and radiotherapy or any clinico-pathological parameter. All specimens were positive for at least one of the immunohistochemical markers. Conclusion To the best of our knowledge this is the first study concluding that the expression of melanocytic markers such as melan-A and tyrosinase is not influenced by radiotherapy or any clinico-pathological parameter. Moreover, when tyrosinase and melan-A are used together, 100% of the formalin-fixed, paraffin-embedded uveal melanoma samples tested positive for one of those markers.

Persistent activation of NF-kappaB related to IkappaB's degradation profiles during early chemical hepatocarcinogenesis

Rebeca Garcia-Roman — Thu,19 Apr 2007

Rebeca Garcia-Roman, Julio Isael Perez-Carreon, Adriana Marquez-Quinones, Martha Estela Salcido-Neyoy, Saul Villa-Trevino

Journal of Carcinogenesis 2007 6(1):5-5

Background To define the NF-kappaB activation in early stages of hepatocarcinogenesis and its IkappaB's degradation profiles in comparison to sole liver regeneration. Methods Western-blot and EMSA analyses were performed for the NF-kappaB activation. The transcriptional activity of NF-kappaB was determined by RT-PCR of the IkappaB-α mRNA. The IkappaB's degradation proteins were determined by Western-blot assay. Results We demonstrated the persistent activation of NF-kappaB during early stages of hepatocarcinogenesis, which reached maximal level 30 min after partial hepatectomy. The DNA binding and transcriptional activity of NF-kappaB, were sustained during early steps of hepatocarcinogenesis in comparison to only partial hepatectomy, which displayed a transitory NF-kappaB activation. In early stages of hepatocarconogenesis, the IkappaB-α degradation turned out to be acute and transitory, but the low levels of IkappaB-β persisted even 15 days after partial hepatectomy. Interestingly, IkappaB-β degradation is not induced after sole partial hepatectomy. Conclusion We propose that during liver regeneration, the transitory stimulation of the transcription factor response, assures blockade of NF-kappaB until recovery of the total mass of the liver and the persistent NF-kappaB activation in early hepatocarcinogenesis may be due to IkappaB-β and IkappaB-α degradation, mainly IkappaB-β degradation, which contributes to gene transcription related to proliferation required for neoplasic progression.

Colon-available raspberry polyphenols exhibit anti-cancer effects on in vitro models of colon cancer

Emma M Coates — Wed,18 Apr 2007

Emma M Coates, Gina Popa, Chris IR Gill, Mark J McCann, Gordon J McDougall, Derek Stewart, Ian Rowland

Journal of Carcinogenesis 2007 6(1):4-4

Background There is a probable association between consumption of fruit and vegetables and reduced risk of cancer, particularly cancer of the digestive tract. This anti-cancer activity has been attributed in part to anti-oxidants present in these foods. Raspberries in particular are a rich source of the anti-oxidant compounds, such as polyphenols, anthocyanins and ellagitannins. Methods A "colon-available" raspberry extract (CARE) was prepared that contained phytochemicals surviving a digestion procedure that mimicked the physiochemical conditions of the upper gastrointestinal tract. The polyphenolic-rich extract was assessed for anti-cancer properties in a series of in vitro systems that model important stages of colon carcinogenesis, initiation, promotion and invasion. Results The phytochemical composition of CARE was monitored using liquid chromatography mass spectrometry. The colon-available raspberry extract was reduced in anthocyanins and ellagitannins compared to the original raspberry juice but enriched in other polyphenols and polyphenol breakdown products that were more stable to gastrointestinal digestion. Initiation - CARE caused significant protective effects against DNA damage induced by hydrogen peroxide in HT29 colon cancer cells measured using single cell microgelelectrophoresis. Promotion - CARE significantly decreased the population of HT29 cells in the G 1 phase of the cell cycle, effectively reducing the number of cells entering the cell cycle. However, CARE had no effect on epithelial integrity (barrier function) assessed by recording the trans-epithelial resistance (TER) of CACO-2 cell monolayers. Invasion - CARE caused significant inhibition of HT115 colon cancer cell invasion using the matrigel invasion assay. Conclusion The results indicate that raspberry phytochemicals likely to reach the colon are capable of inhibiting several important stages in colon carcinogenesis in vitro .

Genistein chemoprevention of prostate cancer in TRAMP mice

Jun Wang — Fri,16 Mar 2007

Jun Wang, Isam-Eldin Eltoum, Coral A Lamartiniere

Journal of Carcinogenesis 2007 6(1):3-3

Epidemiological studies suggest an inverse association between soy intake and prostate cancer risk. Genistein, the predominant phytoestrogen in soy food, has been proposed as a potential chemopreventive agent due to its anti-estrogen and tyrosine kinase inhibitory effects. To determine the most effective period for genistein chemoprevention, the Tr ansgenic a denocarcinoma m ouse p rostate (TRAMP) model was used. The treatments were 250 mg genistein/kg AIN-76A diet 1) prepubertally only, 2) in adulthood only or 3) through out life. Controls received AIN-76A diet. By 28 weeks of age, 100% TRAMP mice fed control diet developed prostatic intraepithelial neoplasia (PIN) or adenocarcinomas with 6%, 16%, 44% and 34% developing high grade PIN, well differentiated, moderately differentiated and poorly differentiated prostatic adenocarcinomas, respectively. Prepubertal only (1-35 days postpartum) and adult only genistein treatments (12 - 28 weeks) resulted in 6% and 29% decreases in poorly-differentiated cancerous lesions compared with controls, respectively. The most significant effect was seen in the TRAMP mice exposed to genistein throughout life (1-28 weeks) with a 50% decrease in poorly-differentiated cancerous lesions. In a separate experiment in castrated TRAMP mice, dietary genistein suppressed the development of advanced prostate cancer by 35% compared with controls. Of the tumors that developed in castrated TRAMP mice, 100% were poorly-differentiated in contrast to the 37% of noncastrated TRAMP mice that developed poorly-differentiated tumors. ICI 182,780 (ICI), genistein and estrogen down-regulated androgen receptor (AR), estrogen receptor alpha (ER-α) and progesterone receptor (PR) in the prostates of C57BL/6 mice, and act independently of ER. Our data obtained in intact and castrated transgenic mice suggest that genistein may be a promising chemopreventive agent against androgen-dependent and independent prostate cancers.

Expression and migratory analysis of 5 human uveal melanoma cell lines for CXCL12, CXCL8, CXCL1, and HGF

Sebastian Di Cesare — Mon,29 Jan 2007

Sebastian Di Cesare, Jean-Claude Marshall, Patrick Logan, Emilia Antecka, Dana Faingold, Shawn C Maloney, Miguel N Burnier Jr

Journal of Carcinogenesis 2007 6(1):2-2

Background The aim of this study was to characterize the presence and roles of CXCL12, CXCL8, CXCL1, and HGF in five human uveal melanoma cell lines, using different methods, in order to ascertain their significance in this disease. Methods Five human uveal melanoma cell lines (92.1, SP6.5, MKT-BR, OCM-1, and UW-1) of known proliferative, invasive, and metastatic potential were used in this experiment. A migration assay was used in order to assess the responsiveness of each cell line towards the four chosen chemotactic factors. Immunohistochemistry was then performed for all five cell lines (cytospins) using antibodies directed toward CXCL1, CXCL8 and their receptors CXCR2 and CXCR1 respectively. Quantitative real-time PCR was then performed on all five cell lines in order to establish the presence of these four chemotactic factors. Results All five human uveal melanoma cell lines migrated towards the four chosen chemotactic factors at a level greater than that of the negative control. Chemokines CXCL1 and CXCL8 resulted in the greatest number of migrating cells in all five of our cell lines. Immunohistochemistry confirmed the expression of CXCL1, CXCL8, and their receptors CXCR2 and CXCR1 in all five of the cell lines. Quantitative real-time PCR results established expression of CXCL8, CXCL1, and HGF in all 5 cell lines tested. CXCL1 and CXCL8 are highly expressed in SP6.5 and UW-1. None of the five cell lines expressed any detectable levels of CXCL12. Conclusion The migratory ability of the 5 human uveal melanoma cell lines was positively influenced by the four chemotactic factors tested, namely CXCL12, CXCL8, CXCL1, and HGF. Self-expression of chemotactic factors CXCL8, CXCL1, and HGF may indicate an autocrine system, which perhaps contributes to the cells' metastatic ability in vivo .

Mitochondrial DNA sequence variants in epithelial ovarian tumor subtypes and stages

Felix O Aikhionbare — Fri,26 Jan 2007

Felix O Aikhionbare, Sharifeh Mehrabi, K Kumaresan, Mojgan Zavareh, Moshood Olatinwo, Kunle Odunsi, Edward Partridge

Journal of Carcinogenesis 2007 6(1):1-1

Background A majority of primary ovarian neoplasms arise from cell surface epithelium of the ovaries. Although old age and a positive family history are associated risk factors, the etiology of the epithelial ovarian tumors is not completely understood. Additionally, knowledge of factors involved in the histogenesis of the various subtypes of this tumor as well as those factors that promote progression to advanced stages of ovarian malignancy are largely unknown. Current evidence suggests that mitochondrial alterations involved in cellular signaling pathways may be associated with tumorigenesis. Methods In this study, we determined the presence of polymorphisms and other sequence variants of mitochondrial DNA (mtDNA) in 102 epithelial ovarian tumors including 10 matched normal tissues that paired with some of the tumors. High-resolution restriction endonucleases and PCR-based sequencing were used to assess the mtDNA variants spanning 3.3 kb fragment that comprised the D-Loop and 12S rRNA-tRNA phe , tRNA val , tRNA ser , tRNA asp , tRNA lys , ATPase 6, ATPase 8, cytochrome oxidase I and II genes. Results Three hundred and fifty-two (352) mtDNA sequence variants were identified, of which 238 of 352 (68%) have not been previously reported. There were relatively high frequencies of three mutations in the 12S rRNA gene at np 772, 773, and 780 in stage IIIC endometrioid tumors, two of which are novel (773delT and 780delC), and occurred with a frequency of 100% (7/7). Furthermore, two mutations were observed in serous tumors only at np 1657 in stage IV (10/10), and at np 8221delA in benign cystadenomas (3/3) and borderline tumors (4/4). A high frequency, 81% (13/16) of TC insertion at np 310 was found only in early stages of serous subtype (benign cystadenomas, 3/3; borderline tumors, 4/4; stage I tumors, 2/5 and matched normal tissues 4/4). Conclusion Our findings indicate that certain mtDNA mutations can reliably distinguish the different histologic subtypes of epithelial ovarian tumors. In addition, these data raise the possibility that certain mtDNA mutations may be useful biomarkers for predicting tumor aggressiveness and may play a potential role in tumorigenesis.

FV peptide induces apoptosis in HEp 2 and HeLa cells: An insight into the mechanism of induction

M Sri Balasubashini — Fri,1 Dec 2006

M Sri Balasubashini, S Karthigayan, ST Somasundaram, T Balasubramanian, R Rukkumani, Venugopal P Menon

Journal of Carcinogenesis 2006 5(1):27-27

The present study is an attempt to evaluate the antiproliferative potential of peptide (7.6 kDa) from lionfish ( Pterios volitans ) venom on cultured HEp2 and HeLa cells. Different dose of purified peptide (1, 2 and 4 μg/ml) at different time points (12, 24 and 36 hrs) were tested for antiproliferative index of the peptide. Among them, 2 μg/ml at 24 hrs was found to effectively inhibit cancer cell growth in vitro and did not cause any adverse effect on normal human lymphocytes. Apoptosis was examined by propidium iodide staining, confirmed by the expression of caspase-8 and caspase-3, down regulation of Bcl-2 expression and DNA fragmentation in treated cells, when compared to untreated HEp2 and HeLa cells. Thus fish venom peptide was found to selectively induce apoptosis in cancer cell.

Hepatocellular proliferation in response to agonists of peroxisome proliferator-activated receptor alpha: A role for kupffer cells?

Ibrahim A Alsarra — Mon,27 Nov 2006

Ibrahim A Alsarra, William G Brockmann, Michael L Cunningham, Mostafa Z Badr

Journal of Carcinogenesis 2006 5(1):26-26

Background: It has been proposed that PPARα agonists stimulate Kupffer cells in rodents which in turn, release mitogenic factors leading to hepatic hyperplasia, and eventually cancer. However, Kupffer cells do not express PPARα receptors, and PPARα agonists stimulate hepatocellular proliferation in both TNFα- and TNFα receptor-null mice, casting doubt on the involvement of Kupffer cells in the mitogenic response to PPARα agonists. This study was therefore designed to investigate whether the PPARα agonist PFOA and the Kupffer cell inhibitor methylpalmitate produce opposing effects on hepatocellular proliferation and Kupffer cell activity in vivo , in a manner that would implicate these cells in the mitogenic effects of PPARα agonists. Methods: Male Sprague-Dawley rats were treated intravenously via the tail vein with methylpalmitate 24 hrs prior to perfluorooctanoic acid (PFOA), and were sacrificed 24 hrs later, one hr after an intraperitoneal injection of bromodeoxyuridine (BrdU). Sera were analyzed for TNFα and IL-1β. Liver sections were stained immunohistochemically and quantified for BrdU incorporated into DNA. Results: Data show that PFOA remarkably stimulated hepatocellular proliferation in the absence of significant changes in the serum levels of either TNFα or IL-1β. In addition, methylpalmitate did not alter the levels of these mitogens in PFOA-treated animals, despite the fact that it significantly blocked the hepatocellular proliferative effect of PFOA. Correlation between hepatocellular proliferation and serum levels of TNFα or IL-1β was extremely poor. Conclusion: It is unlikely that mechanisms involving Kupffer cells play an eminent role in the hepatic hyperplasia, and consequently hepatocarcinogenicity attributed to PPARα agonists. This conclusion is based on the above mentioned published data and the current findings showing animals treated with PFOA alone or in combination with methylpalmitate to have similar levels of serum TNFα and IL-1β, which are reliable indicators of Kupffer cell activity, despite a remarkable difference in hepatocellular proliferation.

Combination phenylbutyrate/gemcitabine therapy effectively inhibits in vitro and in vivo growth of NSCLC by intrinsic apoptotic pathways

Bodo Schniewind — Thu,23 Nov 2006

Bodo Schniewind, Kirsten Heintz, Roland Kurdow, Ole Ammerpohl, Anna Trauzold, Doris Emme, Peter Dohrmann, Holger Kalthoff

Journal of Carcinogenesis 2006 5(1):25-25

Background: Standard chemotherapy protocols in NSCLC are of limited clinical benefit. Histone deacetylase (HDAC) inhibitors represent a new strategy in human cancer therapy. In this study the combination of the HDAC inhibitor phenylbutyrate (PB) and the nucleoside analogue gemcitabine (GEM) was evaluated and the mechanisms underlying increased cell death were analyzed. Methods: Dose escalation studies evaluating the cytotoxicity of PB (0.01-100 mM), GEM (0.01-100 μg/ml) and a combination of the two were performed on two NSCLC cell lines (BEN and KNS62). Apoptotic cell death was quantified. The involvement of caspase-dependent cell death and MAP-kinase activation was analyzed. Additionally, mitochondrial damage was determined. In an orthotopic animal model the combined effect of PB and GEM on therapy was analyzed. Results: Applied as a single drug both GEM and PB revealed limited potential to induce apoptosis in KNS62 and Ben cells. Combination therapy was 50-80% (p = 0.012) more effective than either agent alone. On the caspase level, combination therapy significantly increased cleavage of the pro-forms compared to single chemotherapy. The broad spectrum caspase-inhibitor zVAD was able to inhibit caspase cleavage completely, but reduced the frequency of apoptotic cells only by 30%. Combination therapy significantly increased changes in MTP and the release of cyto-c, AIF and Smac/Diabolo into the cytoplasm. Furthermore, the inhibitors of apoptosis c-IAP1 and c-IAP2 were downregulated and it was shown that in combination therapy JNK activation contributed significantly to induction of apoptosis. The size of the primary tumors growing orthotopically in SCID mice treated for 4 weeks with GEM and PB was significantly reduced (2.2-2.7 fold) compared to GEM therapy alone. The Ki-67 (KNS62: p = 0.015; Ben: p = 0.093) and topoisomerase IIα (KNS62: p = 0.008; Ben: p = 0.064) proliferation indices were clearly reduced in tumors treated by combination therapy, whereas the apoptotic index was comparably low in all groups. Conclusion: Therapy combining GEM and the HDAC inhibitor PB initiates a spectrum of apoptosis-inducing mitochondrial and further JNK-dependent events, thereby overcoming the therapeutic resistance of NSCLC tumor cells. In vivo , the combination therapy substantially reduced tumor cell proliferation, suggesting that the well tolerated PB is a useful supplemental therapeutic agent in NSCLC.

IGF-II transgenic mice display increased aberrant colon crypt multiplicity and tumor volume after 1,2-dimethylhydrazine treatment

Daniela Diehl — Tue,21 Nov 2006

Daniela Diehl, Doris Oesterle, Martin W Elmlinger, Andreas Hoeflich, Eckhard Wolf, Harald Lahm

Journal of Carcinogenesis 2006 5(1):24-24

In colorectal cancer insulin-like growth factor II (IGF-II) is frequently overexpressed. To evaluate, whether IGF-II affects different stages of tumorigenesis, we induced neoplastic alterations in the colon of wild-type and IGF-II transgenic mice using 1,2-dimethylhydrazine (DMH). Aberrant crypt foci (ACF) served as markers of early lesions in the colonic mucosa, whereas adenomas and carcinomas characterized the endpoints of tumor development. DMH-treatment led initially to significantly more ACF in IGF-II transgenic than in wild-type mice. This increase in ACF was especially prominent for those consisting of ≥three aberrant crypts (AC). Nevertheless, adenomas and adenocarcinomas of the colon, present after 34 weeks in both genetic groups, were not found at different frequency. Tumor volumes, however, were significantly higher in IGF-II transgenic mice and correlated with serum IGF-II levels. Immunohistochemical staining for markers of proliferation and apoptosis revealed increased cell proliferation rates in tumors of IGF-II transgenic mice without significant affection of apoptosis. Increased proliferation was accompanied by elevated localization of β-catenin in the cytosol and cell nuclei and reduced appearance at the inner plasma membrane. In conclusion, we provide evidence that IGF-II, via activation of the β-catenin signaling cascade, promotes growth of ACF and tumors without affecting tumor numbers.

Tumor suppressor gene alterations in patients with malignant mesothelioma due to environmental asbestos exposure in Turkey

Esra Tug — Tue,22 Aug 2006

Esra Tug, Tuncer Tug, Halit Elyas, Mehmet Coskunsel, Salih Emri

Journal of Carcinogenesis 2006 5(1):23-23

Background: Environmental asbestos exposure can cause the grave lung and pleura malignancies with a high mortality rate, and it is also associated with increased rate of other organ malignancies. Asbestos exposure can develop genotoxic effects and damage in the pleura and lungs. Objective: In this study, we aimed to determine tumor suppressor gene (TSG) loss in genomic DNA which was isolated from pleural fluid and blood samples of patients with Malignant Pleural Mesothelioma (MPM) due to environmental asbestos exposure. Design and patients: Prospective study of period from 2001 to 2003 in 17 patients with MPM. Methods: A total of 12 chromosomal regions were researched by comparing genomic DNA samples isolated from blood and pleural effusion (using PCR, and polyacrilamid gel electrophoresis denaturizing), on 2 different chromosomes which have 9 different polymorphic determinants at 6q and 3 different polymorphic determinants at 9p using molecular genetic methods on 13 patients clinico-pathologically diagnosed MPM. Results: Loss of Heterozygosity (LOH) was determined at D6S275 in one patient, at D6S301 in another, at D6S474 in 2, at ARG1 in 2, at D6S1038 in 2 and at D6S1008 in 3 patients. In 7 (54%) of the13 patients, we found LOH in at least one site. No LOH was determined at any informative loci in 6 patients. Of the 13 patients, no investigated markers were determined at 9p. Conclusion: In this study, genomic DNA samples obtained from MPM patients with asbestos exposure revealed that they contained important genotoxic damage. We found no other study on this subject at molecular level in pleural effusion either in Turkey or in the med-line literature. We believe that this study will provide important support for other research into molecular-genetic variations, both on this subject and other malignancies, and may also constitute a base for early diagnosis and gene therapy research in the future.

Mapping of the methylation pattern of the hMSH2 promoter in colon cancer, using bisulfite genomic sequencing

Hua Zhang — Tue,15 Aug 2006

Hua Zhang, Wei-ling Fu, Qing Huang

Journal of Carcinogenesis 2006 5(1):22-22

The detailed methylation status of CpG sites in the promoter region of hMSH2 gene has yet not to be reported. We have mapped the complete methylation status of the hMSH2 promoter, a region that contains 75 CpG sites, using bisulfite genomic sequencing in 60 primary colorectal cancers. And the expression of hMSH2 was detected by immunohistochemistry. The hypermethylation of hMSH2 was detected in 18.33% (11/60) of tumor tissues. The protein of hMSH2 was detected in 41.67% (25/60) of tumor tissues. No hypermethylation of hMSH2 was detected in normal tissues. The protein of hMSH2 was detected in all normal tissues. Our study demonstrated that hMSH2 hypermethylation and protein expression were associated with the development of colorectal cancer.

Prostate-specific membrane antigen is undetectable in choroidal neovascular membrane

Katyanne Dantas Godeiro — Tue,15 Aug 2006

Katyanne Dantas Godeiro, Ana Carolina de Arantes Frota, Emilia Antecka, Alexandre Nakao Odashiro, Shawn Maloney, Bruno Fernandes, Miguel Noel Burnier

Journal of Carcinogenesis 2006 5(1):21-21

Background: Choroidal neovascular membrane (CNVM) is one of the leading causes of severe visual loss and is often associated with age-related macular degeneration (AMD). Various modalities of treatment, including photocoagulation and surgery, are being considered as options, but with limited success. Prostate-specific membrane antigen (PSMA) is a type II membrane glycoprotein expressed in benign and malignant prostatic tissues, in some non-prostatic tissues, and in the endothelium of tumor-associated neovasculature of non-prostatic neoplasm. Some studies have suggested that the expression of PSMA is restricted to endothelium from tumor-associated neovasculature and might be stimulated by some tumor-secreted angiogenic factors. However, no previous study demonstrating PSMA expression in non-related tumor neovasculature, such as CNVM, has been performed to date. Furthermore, demonstration of PSMA expression in CNVM in AMD patients could reveal a novel target for antineovascular therapy. The purpose of this study was to evaluate the immunohistochemical expression of PSMA in CNVM from AMD. Methods: Immunohistochemical analysis, with a standard avidin-biotin complex technique, was performed using an anti-PSMA mouse monoclonal antibody in 30 specimens of surgically excised CNVM from AMD patients. Antibody to an endothelial cell specific marker, factor VIII, was used to confirm the location of the endothelial cells. Results: The angiogenic microvessels of the 30 cases demonstrated negative staining to PSMA while factor VIII was expressed in all cases. Seventy-five percent of the secretory-acinar epithelium of the prostatic hyperplasia specimen stained positive, confirming that the immunohistochemical technique was correctly performed. Conclusion: The absence of PSMA expression in non-tumoral neovasculature supports the theory, previously suggested, that endothelial cell PSMA expression may be stimulated by one or more tumor-secreted angiogenic factors. Angiogenesis is very important in neoplasia and the endothelial expression of PSMA in tumor-associated neovasculature may represent a target for antineovasculature-based therapy. The absence of PSMA expression in CNVM suggests that PSMA may not be a potential target for antineovasculature-based therapy.

Does architectural lighting contribute to breast cancer?

Mariana G Figueiro — Thu,10 Aug 2006

Mariana G Figueiro, Mark S Rea, John D Bullough

Journal of Carcinogenesis 2006 5(1):20-20

Objectives: There is a growing interest in the role that light plays on nocturnal melatonin production and, perhaps thereby, the incidence of breast cancer in modern societies. The direct causal relationships in this logical chain have not, however, been fully established and the weakest link is an inability to quantitatively specify architectural lighting as a stimulus for the circadian system. The purpose of the present paper is to draw attention to this weakness. Data Sources and Extraction: We reviewed the literature on the relationship between melatonin, light at night, and cancer risk in humans and tumor growth in animals. More specifically, we focused on the impact of light on nocturnal melatonin suppression in humans and on the applicability of these data to women in real-life situations. Photometric measurement data from the lighted environment of women at work and at home is also reported. Data Synthesis: The literature review and measurement data demonstrate that more quantitative knowledge is needed about circadian light exposures actually experienced by women and girls in modern societies. Conclusion: Without such quantitative knowledge, limited insights can be gained about the causal relationship between melatonin and the etiology of breast cancer from epidemiological studies and from parametric studies using animal models.

Characterization of pancreatic lesions from MT- tgfα, Ela- myc and MT- tgfα/Ela- myc single and double transgenic mice

Dezhong Joshua Liao — Wed,5 Jul 2006

Dezhong Joshua Liao, Yong Wang, Jiusheng Wu, Nazmi Volkan Adsay, David Grignon, Fayyaz Khanani, Fazlul H Sarkar

Journal of Carcinogenesis 2006 5(1):19-19

In order to identify good animal models for investigating therapeutic and preventive strategies for pancreatic cancer, we analyzed pancreatic lesions from several transgenic models and made a series of novel findings. Female MT- tgfα mice of the MT100 line developed pancreatic proliferation, acinar-ductal metaplasia, multilocular cystic neoplasms, ductal adenocarcinomas and prominent fibrosis, while the lesions in males were less severe. MT- tgfα-ES transgenic lines of both sexes developed slowly progressing lesions that were similar to what was seen in MT100 males. In both MT100 and MT- tgfα-ES lines, TGFα transgene was expressed mainly in proliferating ductal cells. Ela- myc transgenic mice with a mixed C57BL/6, SJL and FVB genetic background developed pancreatic tumors at 2-7 months of age, and half of the tumors were ductal adenocarcinomas, similar to what was reported originally by Sandgren et al [1]. However, in 20% of the mice, the tumors metastasized to the liver. MT100/Ela- myc and MT- tgfα-ES/Ela- myc double transgenic mice developed not only acinar carcinomas and mixed carcinomas as previously reported but also various ductal-originated lesions, including multilocular cystic neoplasms and ductal adenocarcinomas. The double transgenic tumors were more malignant and metastasized to the liver at a higher frequency (33%) compared with the Ela- myc tumors. Sequencing of the coding region of p16ink4 , k- ras and Rb cDNA in small numbers of pancreatic tumors did not identify mutations. The short latency for tumor development, the variety of tumor morphology and the liver metastases seen in Ela- myc and MT- tgfα/Ela- myc mice make these animals good models for investigating new therapeutic and preventive strategies for pancreatic cancer.

Invasive aspergillosis causing small bowel infarction in a patient of carcinoma breast undergoing chemotherapy

Amit Chaudhary — Tue,6 Jun 2006

Amit Chaudhary, Vinod Jain, Rama S Dwivedi, Samir Misra

Journal of Carcinogenesis 2006 5(1):18-18

Background: To report a 45 year old lady presenting with proximal jejunal gangrene due to invasive Aspergillosis. The patient was undergoing adjuvant chemotherapy for advance carcinoma of breast (Stage IV). Methods: The patient was referred to our surgical emergency for acute abdominal symptoms for 6 hours. Histopathology revealed bowel wall necrosis and vascular invasion by Aspergillus Fumigatus. Postoperative recovery was uneventful and the patient received Amphotericin-B (1 mg/kg/day) for invasive aspergillosis. Invasive pulmonary aspergillosis was confirmed by isolating Aspergillus Fumigatus from bronchoalveolar lavage and by a positive circulating galactomannan test (ELISA Assay). Results: Detailed history revealed dry cough and two episodes of haemoptesis for 2 weeks. Haemogram and counts revealed anemia and neutropenia. Plain X - ray of the abdomen showed multiple air fluid levels and ultrasound of the abdomen revealed distended bowel loops. On exploration small bowel was found to be gangrenous. The patient was successfully managed by supportive treatment and conventional intravenous Amphotericin-B for 2 weeks. The lady was discharged one week after completion of antifungal therapy and one month later she underwent toilet mastectomy. The lady came to follow up for 1 year and she is currently under hormone therapy. Conclusion: With the emergence of new and powerful immunosuppressive, anticancer drugs and potent antibiotics the survival of transplant and critically ill patients has remarkably increased but it has shown a significant rise in the incidence of invasive opportunistic fungal infections. We conclude hat the diagnosis of invasive gastrointestinal aspergillosis may be considered in a neutropenic patient with acute abdominal symptoms.

The association between telomerase activity and expression of its RNA component (hTR) in breast cancer patients: The importance of DNase treatment

Saied Hosseini-Asl — Fri,2 Jun 2006

Saied Hosseini-Asl, Mohammad H Modarressi, Morteza Atri, Mohamed Salhab, Kefah Mokbel, Parvin Mehdipour

Journal of Carcinogenesis 2006 5(1):17-17

Telomerase is a ribonucleoprotein enzyme that compensates for the telomere length shortening which occurs during the cell cycle. Telomerase activity has been detected in most tumours but not in somatic cells. However, hTR; the RNA component of telomerase; has been reported to be universally expressed in both cancerous and non-cancerous tissues. Tumour samples from 50 patients with primary invasive breast cancer were collected. The TRAP assay was used to detect telomerase activity. RT-PCR on cDNA and DNased cDNA samples and control groups was used to detect the expression of hTR, GAPDH and PGM1 genes. Seventy-two percent of samples showed telomerase activity. DNA contamination was detected in 36 (72%) of RNA samples. Without performing DNase treatment, 49 (98%) of all samples showed hTR expression, but with the application of this strategy, hTR expression decreased from 98% to 64%. A significant association (p < 0.001) between hTR expression and telomerase activity was observed. Among the 32 hTR positive samples, 30 had telomerase activity and among the 18 hTR negative samples, telomerase activity was observed in 6 cases. Thus the application of this strategy could provide an applicable tool to use instead of the TRAP assay thus facilitating telomerase research in cancer genetic investigations.

The mRNA expression of IGF-1 and IGF-1R in human breast cancer: Association with clinico-pathological parameters

W Al Sarakbi — Thu,25 May 2006

W Al Sarakbi, YM Chong, SLJ Williams, AK Sharma, K Mokbel

Journal of Carcinogenesis 2006 5(1):16-16

Resveratrol, but not EGCG, in the diet suppresses DMBA-induced mammary cancer in rats

Timothy Whitsett — Mon,15 May 2006

Timothy Whitsett, Mark Carpenter, Coral A Lamartiniere

Journal of Carcinogenesis 2006 5(1):15-15

Despite the advent of new and aggressive therapeutics, breast cancer remains a leading killer among women; hence there is a need for the prevention of this disease. Several naturally occurring polyphenols have received much attention for their health benefits, including anti-carcinogenic properties. Two of these are resveratrol, a component of red grapes, and epigallocatechin-3-gallate (EGCG), the major catechin found in green tea. In this study, we tested the hypothesis that these two polyphenols protect against chemically-induced mammary cancer by modulating mammary gland architecture, cell proliferation, and apoptosis. Female Sprague-Dawley CD rats were exposed to either resveratrol (1 g/kg AIN-76A diet), EGCG (0.065% in the drinking water), or control diet (AIN-76A) for the entirety of their life starting at birth. At 50 days postpartum, rats were treated with 60 mg dimethylbenz[a]anthracene (DMBA)/kg body weight to induce mammary cancer. Resveratrol, but not EGCG, suppressed mammary carcinogenesis (fewer tumors per rat and longer tumor latency). Analysis of mammary whole mounts from 50-day-old rats revealed that resveratrol, but not EGCG, treatment resulted in more differentiated lobular structures. Bromodeoxyuridine (BrdU) incorporation studies showed that resveratrol treatment caused a significant reduction in proliferative cells in mammary terminal ductal structures at 50 days postpartum, making them less susceptible to carcinogen insult. The epithelial cells of terminal end buds in the mammary glands of resveratrol-treated rats also showed an increase in apoptotic cells compared to the control or EGCG-treated rats as measured by a DNA fragmentation assay. At the given doses, resveratrol treatment resulted in a serum resveratrol concentration of 2.00 μM, while treatment with EGCG resulted in a serum EGCG concentration of 31.06 nM. 17β-Estradiol, progesterone, and prolactin concentrations in the serum were not significantly affected by resveratrol or EGCG. Neither polyphenol treatment resulted in toxicity as tested by alterations in body weights, diet and drink consumptions, and day to vaginal opening. We conclude that resveratrol in the diet can reduce susceptibility to mammary cancer, while EGCG in the drinking water at the dose used was not effective.

Reactive oxygen species: Role in the development of cancer and various chronic conditions

Gulam Waris — Thu,11 May 2006

Gulam Waris, Haseeb Ahsan

Journal of Carcinogenesis 2006 5(1):14-14

Oxygen derived species such as superoxide radical, hydrogen peroxide, singlet oxygen and hydroxyl radical are well known to be cytotoxic and have been implicated in the etiology of a wide array of human diseases, including cancer. Various carcinogens may also partly exert their effect by generating reactive oxygen species (ROS) during their metabolism. Oxidative damage to cellular DNA can lead to mutations and may, therefore, play an important role in the initiation and progression of multistage carcinogenesis. The changes in DNA such as base modification, rearrangement of DNA sequence, miscoding of DNA lesion, gene duplication and the activation of oncogenes may be involved in the initiation of various cancers. Elevated levels of ROS and down regulation of ROS scavengers and antioxidant enzymes are associated with various human diseases including various cancers. ROS are also implicated in diabtes and neurodegenerative diseases. ROS influences central cellular processes such as proliferation a, apoptosis, senescence which are implicated in the development of cancer. Understanding the role of ROS as key mediators in signaling cascades may provide various opportunities for pharmacological intervention.

Cervical cancer with Human Papilloma Virus and Epstein Barr Virus positive

Adi Prayitno — Wed,10 May 2006

Adi Prayitno

Journal of Carcinogenesis 2006 5(1):13-13

The Early-7 (E7) protein of HPV binds to the underphosphorelated form of the tumor suppressor protein - pRb and displaces the E2F transcription factor that is normally bound by pRb. The latent membrane protein-1 (LMP-1) of EBV prevents apoptosis of B cells by up regulating the expression of bcl-2, and it activates growth promoting pathway that are normally triggered by T cell - derivate signal. The aims of this study to know that in cervical cancer stay HPV and EBV. DNA was isolated from nineteen sample cervical cancer tissues frozen section. Diagnose related with HPV and EBV was made by Polymerase Chains Reaction (PCR). The result of this experiment showed that from 19 samples diagnosed as cervical cancer, 17 samples are positive HPV and 13 samples had HPV and EBV positive. The conclusion of this experiment is 89% of cervical cancers are infected with HPV and 68% also infected with HPV and EBV.

Simple tandem repeat (TTTA) n polymorphism in CYP19 (aromatase) gene and breast cancer risk in Nigerian women

Michael N Okobia — Tue,9 May 2006

Michael N Okobia, Clareann H Bunker, Joseph M Zmuda, Emmanuel R Ezeome, Stanley NC Anyanwu, Emmanuel EO Uche, Joseph Ojukwu, Lewis H Kuller, Robert E Ferrell

Journal of Carcinogenesis 2006 5(1):12-12

Background: Breast cancer is the most common cancer and the leading cause of cancer related deaths in women worldwide. The incidence of the disease is increasing globally and this increase is occurring at a faster rate in population groups that hirtherto enjoyed low incidence. This study was designed to evaluate the role of a simple tandem repeat polymorphism (STRP) in the aromatase (CYP19) gene in breast cancer susceptibility in Nigerian women, a population of indigenous sub-Saharan African ancestry. Methods: A case-control study recruiting 250 women with breast cancer and 250 women without the disease from four University Teaching Hospitals in Southern Nigeria was carried out between September 2002 and April 2004. Participants were recruited from the surgical outpatient clinics and surgical wards of the Nigerian institutions. A polymerase chain reaction (PCR)-based assay was employed for genotyping and product sizes were detected with an ABI 3730 DNA Analyzer. Results: Conditional logistic regression analysis revealed that harboring the putative high risk genotypes conferred a 29% increased risk of breast cancer when all women in the study were considered (Odds ratio [OR] = 1.29, 95% confidence interval [CI] 0.83-2.00), although this association was not statistically significant. Subgroup analysis based on menopausal status showed similar results among premenopausal women (OR = 1.35, 95% CI 0.76-2.41 and postmenopausal women (OR = 1.27, 95% CI 0.64-2.49). The data also demonstrated marked differences in the distribution of (TTTA) n repeats in Nigerian women compared with other populations. Conclusion: This study has shown that harboring 10 or more repeats of the microsatellite (TTTA) n repeats of the CYY19 gene is associated with a modest increased risk of breast cancer in Nigerian women.

A long-term investigation of the anti-hepatocarcinogenic potential of an indigenous medicine comprised of Nigella sativa, Hemidesmus indicus and Smilax glabra

SS Iddamaldeniya — Tue,9 May 2006

SS Iddamaldeniya, MI Thabrew, SMDN Wickramasinghe, N Ratnatunge, MG Thammitiyagodage

Journal of Carcinogenesis 2006 5(1):11-11

Background: A decoction comprised of Nigella sativa seeds, Hemidesmus indicus root bark and Smilax glabra rhizome is being recommended for cancer patients by a family of traditional medical practitioners of Sri Lanka. Previous investigations have demonstrated that a short term (10 weeks) treatment with the decoction can significantly inhibit diethylnitrosamine (DEN) mediated expression of Glutathione S-transferase P form (GST-P) in rat liver. The objective of the present investigation was to determine whether long term (16 months) treatment with the decoction would be successful in inhibiting in rat livers, not only DEN- mediated expression of GST-P, but also the carcinogen mediated development of overt tumours (OT) or histopathological changes leading to tumour development (HT). Methods: Thirty-six male Wistar rats were divided into 3 groups of 12 each. Groups 1 and 2 were injected intraperitoneally (i.p) with DEN (200 mg/kg) while group 3 was injected normal saline (NS). Twenty-four hours later, decoction (DC; 6 g/kg body weight/day) was orally administered to group 1 rats, while groups 2 and 3 (DEN-control and normal control) were given distilled water (DW). Treatment with DC or DW continued for 16 months. At the end of the 9 th month and 16 th months (study 1 and study 2 respectively), six rats from each group were sacrificed, and livers observed for OT or HT, both visually and by subjecting liver sections to staining with Haemotoxylin and Eosin (H & E), Sweet's Silver stain (for reticulin fibers), Periodic Acid Schiff (PAS) staining (for glycogen), and immunohistochemical staining (for GST-P). Results: At the end of 9 months (study 1) a hepatocellular adenoma (HA) developed in one of the rats in the DEN + DW treated group (group 2). At the end of 16 months (study 2), livers of all rats of group 2 developed OT and HT. Large areas of GST-P positive foci were also observed. No OT, HT or GST-P positive foci were detected in any of the other groups. Conclusion: Protection against DEN-mediated carcinogenic changes in rat liver can be achieved by long term treatment with the DC comprised of N. sativa seeds, S. glabra rhizome and H. indicus root bark.

Effects of quercetin on insulin-like growth factors (IGFs) and their binding protein-3 (IGFBP-3) secretion and induction of apoptosis in human prostate cancer cells

Marati R Vijayababu — Thu,6 Apr 2006

Marati R Vijayababu, A Arunkumar, P Kanagaraj, J Arunakaran

Journal of Carcinogenesis 2006 5(1):10-10

Background: Quercetin, the predominant flavonoid, has been reported to lower the risk of several cancers. This flavonoid found in onion, grapes, green vegetables, etc. has been shown to possess potent antiproliferative effects against various malignant cells. This study was designed to investigate its effects on insulin-like growth factors (IGFs) and their binding protein-3 (IGFBP-3) proteins secretion and also apoptosis induction in the human prostate cancer cell line, PC-3. Methods: We evaluated the secretion of IGF-I, -II and IGFBP-3 in quercetin treated cells by immunoradiometric (IRMA) method. Apoptosis was studied in quercetin treated cells by TUNEL and DNA fragmentation. Protein expressions of Bcl-2, Bcl-x L , Bax and caspase-3 were studied by western blot. Results: At a dose of 100 μM concentration, we observed increased IGFBP-3 accumulation in PC-3 cells conditioned medium with a dose dependent increase with 2 fold over a base line, and significantly reduced the both IGF-I and IGF-II levels. Apoptosis induction was also confirmed by TUNEL assay. Bcl-2 and Bcl-x L protein expressions were significantly decreased and Bax and caspase-3 were increased. Conclusion: These results suggest that the decreased level of IGFs could be due to the increased levels of IGFBP-3, because of the high binding affinity towards IGFs, thereby decreasing the cell proliferation. The increased level of IGFBP-3 was associated with increased pro-apoptotic proteins and apoptosis in response to quercetin, suggesting it may be a p53-independent effector of apoptosis in prostate cancer cells.

The yin and yang of 15-lipoxygenase-1 and delta-desaturases: Dietary omega-6 linoleic acid metabolic pathway in prostate

Uddhav Kelavkar — Mon,27 Mar 2006

Uddhav Kelavkar, Yan Lin, Doug Landsittel, Uma Chandran, Rajiv Dhir

Journal of Carcinogenesis 2006 5(1):9-9

One of the major components in high-fat diets (Western diet) is the omega (ω, n)-6 polyunsaturated fatty acid (PUFA) called linoleic acid (LA). Linoleic acid is the precursor for arachidonic acid (AA). These fatty acids are metabolized to an array of eicosanoids and prostaglandins depending upon the enzymes in the pathway. Aberrant expression of the catabolic enzymes such as cyclooxygenases (COX-1 and/or -2) or lipoxygenases (5-LO, 12-LO, 15-LO-1, and 15-LO-2) that convert PUFA either AA and/or LA to bioactive lipid metabolites appear to significantly contribute to the development of PCa. However, PUFA and its cellular interactions in PCa are poorly understood. We therefore examined the mRNA levels of key enzymes involved in the LA and AA pathways in 18 human donor (normal) prostates compared to 60 prostate tumors using the Affymetrix U95Av2 chips. This comparative (normal donor versus prostate cancer) study showed that: 1) the level of 15-LO-1 expression (the key enzyme in the LA pathway) is low ( P < 0.001), whereas the levels of delta-5 desaturase ( P < 0.001, the key enzyme in the AA pathway), delta-6 desaturase ( P = 0.001), elongase ( P = 0.16) and 15-lipoxygenase-2 (15-LO-2, P = 0.74) are higher in donor (normal) prostates, and 2) Contrary to the observation in the normal tissues, significantly high levels of only 15-LO-1; whereas low levels of delta-6 desaturase, elongase, delta-5 desaturase and 15-LO-2 respectively, were observed in PCa tissues. Although the cyclooxygenase (COX)-1 and COX-2 mRNA levels were high in PCa, no significant differences were observed when compared in donor tissues. Our study underscores the importance of promising dietary intervention agents such as the omega-3 fatty acids as substrate competitors of LA/AA, aimed primarily at high 15-LO-1 and COX-2 as the molecular targets in PCa initiation and/or progression.

"The case for clean indoor air"

Fred M Jacobs — Fri,10 Feb 2006

Fred M Jacobs

Journal of Carcinogenesis 2006 5(1):8-8

Clean air is the key to clean lungs: Secondhand smoke is injurious to health

Gopala Kovvali — Tue,7 Feb 2006

Gopala Kovvali

Journal of Carcinogenesis 2006 5(1):7-7

Post-initiation chlorophyllin exposure does not modulate aflatoxin-induced foci in the liver and colon of rats

Gayle A Orner — Mon,6 Feb 2006

Gayle A Orner, Bill D Roebuck, Roderick H Dashwood, George S Bailey

Journal of Carcinogenesis 2006 5(1):6-6

Chlorophyllin (CHL) is a promising chemopreventive agent believed to block cancer primarily by inhibiting carcinogen uptake through the formation of molecular complexes with the carcinogens. However, recent studies suggest that CHL may have additional biological effects particularly when given after the period of carcinogen treatment. This study examines the post-initiation effects of CHL towards aflatoxin B1 (AFB 1 )-induced preneoplastic foci of the liver and colon. The single concentration of CHL tested in this study (0.1% in the drinking water) had no significant effects on AFB 1 -induced foci of the liver and colons of rats.

Fas ligand expression in human and mouse cancer cell lines; a caveat on over-reliance on mRNA data

Aideen E Ryan — Thu,2 Feb 2006

Aideen E Ryan, Sinead Lane, Fergus Shanahan, Joe O'Connell, Aileen M Houston

Journal of Carcinogenesis 2006 5(1):5-5

Background: During carcinogenesis, tumors develop multiple mechanisms for evading the immune response, including upregulation of Fas ligand (FasL/CD95L) expression. Expression of FasL may help to maintain tumor cells in a state of immune privilege by inducing apoptosis of anti-tumor immune effector cells. Recently this idea has been challenged by studies reporting that tumor cells of varying origin do not express FasL. In the present study, we aimed to comprehensively characterize FasL expression in tumors of both murine and human origin over a 72 hour time period. Methods: RNA and protein was extracted from six human (SW620, HT29, SW480, KM12SM, HCT116, Jurkat) and three mouse (CMT93, CT26, B16F10) cancer cell lines at regular time intervals over a 72 hour time period. FasL expression was detected at the mRNA level by RT-PCR, using intron spanning primers, and at the protein level by Western Blotting and immunofluorescence, using a polyclonal FasL- specific antibody. Results: Expression of FasL mRNA and protein was observed in all cell lines analysed. However, expression of FasL mRNA varied dramatically over time, with cells negative for FasL mRNA at many time points. In contrast, 8 of the 9 cell lines constitutively expressed FasL protein. Thus, cells can abundantly express FasL protein at times when FasL mRNA is absent. Conclusion: These findings demonstrate the importance of complete analysis of FasL expression by tumor cells in order to fully characterize its biological function and may help to resolve the discrepancies present in the literature regarding FasL expression and tumor immune privilege.

The influence of the pituitary tumor transforming gene-1 (PTTG-1) on survival of patients with small cell lung cancer and non-small cell lung cancer

Nina Rehfeld — Fri,20 Jan 2006

Nina Rehfeld, Helene Geddert, Abedelsalam Atamna, Astrid Rohrbeck, Guillermo Garcia, Slawek Kliszewski, Judith Neukirchen, Ingmar Bruns, Ulrich Steidl, Roland Fenk, Helmut E Gabbert, Ralf Kronenwett, Rainer Haas, Ulrich-Peter Rohr

Journal of Carcinogenesis 2006 5(1):4-4

Background: PTTG-1 (pituitary tumor transforming gene) is a novel oncogene that is overexpressed in tumors, such as pituitary adenoma, breast and gastrointestinal cancers as well as in leukemia. In this study, we examined the role of PTTG-1 expression in lung cancer with regard to histological subtype, the correlation of PTTG-1 to clinical parameters and relation on patients' survival. Methods: Expression of PTTG-1 was examined immunohistochemically on formalin-fixed, paraffin-embedded tissue sections of 136 patients with small cell lung cancer (SCLC) and 91 patients with non-small cell lung cancer (NSCLC), retrospectively. The intensity of PTTG-1 expression as well as the proportion of PTTG-1 positive cells within a tumor was used for univariate and multivariate analysis. Results: PTTG-1 expression was observed in 64% of SCLC tumors and in 97.8% of NSCLC tumors. In patients with SCLC, negative or low PTTG-1 expression was associated with a shorter mean survival time compared with patients with strong PTTG-1 expression (265 ± 18 days vs. 379 ± 66 days; p = 0.0291). Using the Cox regression model for multivariate analysis, PTTG-1 expression was a significant predictor for survival next to performance status, tumor stage, LDH and hemoglobin. In contrast, in patients with NSCLC an inverse correlation between survival and PTTG-1 expression was seen. Strong PTTG-1 expression was associated with a shorter mean survival of 306 ± 58 days compared with 463 ± 55 days for those patients with no or low PTTG-1 intensities (p = 0.0386). Further, PTTG-1 expression was associated with a more aggressive NSCLC phenotype with an advanced pathological stage, extensive lymph node metastases, distant metastases and increased LDH level. Multivariate analysis using Cox regression confirmed the prognostic relevance of PTTG-1 expression next to performance status and tumor stage in patients with NSCLC. Conclusion: Lung cancers belong to the group of tumors expressing PTTG-1. Dependent on the histological subtype of lung cancer, PTTG-1 expression was associated with a better outcome in patients with SCLC and a rather unfavourable outcome for patients with NSCLCs. These results may reflect the varying role of PTTG-1 in the pathophysiology of the different histological subtypes of lung cancer.

Departure from multiplicative interaction for catechol-O-methyltransferase genotype and active/passive exposure to tobacco smoke among women with breast cancer

Brian D Bradbury — Tue,17 Jan 2006

Brian D Bradbury, Jemma B Wilk, Ann Aschengrau, Timothy L Lash

Journal of Carcinogenesis 2006 5(1):3-3

Background: Women with homozygous polymorphic alleles of catechol-O-methyltransferase (COMT-LL) metabolize 2-hydroxylated estradiol, a suspected anticarcinogenic metabolite of estrogen, at a four-fold lower rate than women with no polymorphic alleles (COMT-HH) or heterozygous women (COMT-HL). We hypothesized that COMT-LL women exposed actively or passively to tobacco smoke would have higher exposure to 2-hydroxylated estradiol than never-active/never passive exposed women, and should therefore have a lower risk of breast cancer than women exposed to tobacco smoke or with higher COMT activity. Methods: We used a case-only design to evaluate departure from multiplicative interaction between COMT genotype and smoking status. We identified 502 cases of invasive incident breast cancer and characterized COMT genotype. Information on tobacco use and other potential breast cancer risk factors were obtained by structured interviews. Results: We observed moderate departure from multiplicative interaction for COMT-HL genotype and history of ever-active smoking (adjusted odds ratio [aOR] = 1.6, 95% confidence interval [CI]: 0.7, 3.8) and more pronounced departure for women who smoked 40 or more years (aOR = 2.3, 95% CI: 0.8, 7.0). We observed considerable departure from multiplicative interaction for COMT-HL genotype and history of ever-passive smoking (aOR = 2.0, 95% CI: 0.8, 5.2) or for having lived with a smoker after age 20 (aOR = 2.8, 95% CI: 0.8, 10). Conclusion: With greater control over potential misclassification errors and a large case-only population, we found evidence to support an interaction between COMT genotype and tobacco smoke exposure in breast cancer etiology.

Expression of Hyaluronan in human tumor progression

Rajeev K Boregowda — Tue,10 Jan 2006

Rajeev K Boregowda, Hitesh N Appaiah, Manjunath Siddaiah, Sunil B Kumarswamy, Sunila Sunila, KN Thimmaiah, Karuna Kumar Mortha, Bryan Toole, Shib D Banerjee

Journal of Carcinogenesis 2006 5(1):2-2

Background: The development and progression of human tumors is accompanied by various cellular, biochemical and genetic alterations. These events include tumor cells interaction with extracellular matrix molecules including hyaluronan (HA). Hyaluronan is a large polysaccharide associated with pericellular matrix of proliferating, migrating cells. Its implication in malignant transformation, tumor progression and with the degree of differentiation in various invasive tumors has well accepted. It has been well known the role HA receptors in tumor growth and metastasis in various cancer tissues. Previously we have observed the unified over expression of Hyaluronic Acid Binding Protein (HABP), H11B2C2 antigen by the tumor cells in various types progressing tumor tissues with different grades. However, the poor understanding of relation between HA and HA-binding protein expression on tumor cells during tumor progression as well as the asymmetric observations of the role of HA expression in tumor progression prompted us to examine the degree of HA expression on tumor cells vs. stroma in various types of human tumors with different grades. Methods: In the present study clinically diagnosed tumor tissue samples of different grades were used to screen the histopathological expression of hyaluronan by using b-PG (biotinylated proteoglycan) as a probe and we compared the relative HA expression on tumor cells vs. stroma in well differentiated and poorly differentiated tumors. Specificity of the reaction was confirmed either by pre-digesting the tissue sections with hyaluronidase enzyme or by staining the sections with pre-absorbed complex of the probe and HA-oligomers. Results: We show here the down regulation of HA expression in tumor cells is associated with progression of tumor from well differentiated through poorly differentiated stage, despite the constant HA expression in the tumor associated stroma. Conclusion: The present finding enlighten the relative roles of HA expression on tumor vs. stroma during the progression of tumors.

CytoregR inhibits growth and proliferation of human adenocarcinoma cells via induction of apoptosis

J Kumi-Diaka — Mon,9 Jan 2006

J Kumi-Diaka, M Hassanhi, J Brown, K Merchant, C Garcia, W Jimenez

Journal of Carcinogenesis 2006 5(1):1-1

Background: Cancer is one of the devastating neovascular diseases that incapacitate so many people the world over. Recent reports from the National Cancer Institute indicate some significant gain therapy and cancer management as seen in the increase in the 5-year survival rate over the past two decades. Although near-perfect cure rate have been reported in the early-stage disease, these data reveal high recurrence rate and serious side effects including second malignancies and fatalities. Most of the currently used anticancer agents are only effective against proliferating cancer cells. Thus attention has been focused on potential anti-cancer agents capable of killing cancer cells independent of the cell cycle state, to ensure effective elimination of most cancer cells. The objective of this study was to test the chemosensitivity and potential mechanism of action of a novel cancer drug, CytoregR, in a panel of human cancer cells. Methods: the study was performed using a series of bioassays including Trypan blue exclusion, MTS Growth inhibition, LDH-cytotoxicity, TUNEL-Terminal DNA fragmentation Apoptosis Assay, and the Caspase protease CPP32 activity assays. Results: Cytoreg R induced significant dose- and time-dependent inhibition of growth in all the cells; with significant differences in chemosensitivity (P < 0.05) between the target cells becoming more apparent at 48 hr exposure. CytoregR showed no significant effect on normal cells relative to the tumor cells. Growth inhibition in all the cells was due to induction of apoptosis at lower concentrations of cytoregR (> 1:300). CytoregR-induced caspase protease-3 (CPP32) activation significantly and positively correlated with apoptosis induction and growth inhibition; thus implicating CPP32 as the principal death pathway in cytoregR-induced apoptosis. Conclusion: CytoregR exerted a dose-and time-dependent growth inhibitory effect in all the target cells through induction of apoptosis via the CPP32 death pathway, independent of hormonal sensitivity of the cells. The present data indicate that not only could CPP32 provide a potential target for regulation of cytoregR-induced apoptosis but also that cytoregR could play a significant role in chemotherapeutic regimen in many human malignant tumors.

Absence of mutations in the coding sequence of the potential tumor suppressor 3pK in metastatic melanoma

Roland Houben — Tue,20 Dec 2005

Roland Houben, Jurgen C Becker, Ulf R Rapp

Journal of Carcinogenesis 2005 4(1):23-23

Background: Activation of Ras or Raf contributes to tumorigenesis of melanoma. However, constitutive Raf activation is also a characteristic of the majority of benign melanocytic nevi and high intensity signaling of either Ras or Raf was found to induce growth inhibition and senescence rather than transformation. Since the chromosome 3p kinase (3pK)) is a target of the Ras/Raf/Mek/Erk signaling pathway which antagonizes the function of the oncogene and anti-differentiation factor Bmi-1, 3pK may function as a tumor suppressor in tumors with constitutive Ras/Raf activation. Consequently, we tested whether inactivating 3pK mutations are present in melanoma. Methods: 30 metastatic melanoma samples, which were positive for activating mutations of either BRaf or NRas, were analyzed for possible mutations in the 3pk gene. The 10 coding exons and their flanking intron sequences were amplified by PCR and direct sequencing of the PCR products was performed. Results: This analysis revealed that besides the presence of some single nucleotide polymorphisms in the 3pk gene, we could not detect any possible loss of function mutation in any of these 30 metastatic melanoma samples selected for the presence of activating mutations within the Ras/Raf/Mek/Erk signaling pathway. Conclusion: Hence, in melanoma with constitutively active Ras/Raf inactivating mutations within the 3pk gene do not contribute to the oncogenic phenotype of this highly malignant tumor.

New paradigms, new Hopes: the need for socially responsible research on carcinogenesis

Gopala Kovvali — Mon,21 Nov 2005

Gopala Kovvali

Journal of Carcinogenesis 2005 4(1):22-22

Cancer incidence in the south Asian population of California, 1988-2000

Ratnali V Jain — Thu,10 Nov 2005

Ratnali V Jain, Paul K Mills, Arti Parikh-Patel

Journal of Carcinogenesis 2005 4(1):21-21

Background: Although South Asians (SA) form a large majority of the Asian population of U.S., very little is known about cancer in this immigrant population. SAs comprise people having origins mainly in India, Pakistan, Bangladesh and Sri Lanka. We calculated age-adjusted incidence and time trends of cancer in the SA population of California (state with the largest concentration of SAs) between 1988-2000 and compared these rates to rates in native Asian Indians as well as to those experienced by the Asian/Pacific Islander (API) and White, non-Hispanic population (NHW) population of California. Methods: Age adjusted incidence rates observed among the SA population of California during the time period 1988-2000 were calculated. To correctly identify the ethnicity of cancer cases, 'Nam Pehchan' (British developed software) was used to identify numerator cases of SA origin from the population-based cancer registry in California (CCR). Denominators were obtained from the U.S. Census Bureau. Incidence rates in SAs were calculated and a time trend analysis was also performed. Comparison data on the API and the NHW population of California were also obtained from CCR and rates from Globocan 2002 were used to determine rates in India. Results: Between 1988-2000, 5192 cancers were diagnosed in SAs of California. Compared to rates in native Asian Indians, rates of cancer in SAs in California were higher for all sites except oropharyngeal, oesophageal and cervical cancers. Compared to APIs of California, SA population experienced more cancers of oesophagus, gall bladder, prostate, breast, ovary and uterus, as well as lymphomas, leukemias and multiple myelomas. Compared to NHW population of California, SAs experienced more cancers of the stomach, liver and bile duct, gall bladder, cervix and multiple myelomas. Significantly increasing time trends were observed in colon and breast cancer incidence. Conclusion: SA population of California experiences unique patterns of cancer incidence most likely associated with acculturation, screening and tobacco habits. There is need for early diagnosis of leading cancers in SA. If necessary steps are not taken to curb the growth of breast, colon and lung cancer, rates in SA will soon approximate those of the NHW population of California.

Role of retinoic acid receptors in squamous-cell carcinoma in human esophagus

I Bergheim — Tue,8 Nov 2005

I Bergheim, E Wolfgarten, E Bollschweiler, AH Holscher, Ch Bode, A Parlesak

Journal of Carcinogenesis 2005 4(1):20-20

Background: Worldwide, cancer in the esophagus ranks among the 10 most common cancers. Alterations of retinoic acid receptors (e.g. RARα, β, γ, and RXRα, β, γ) expression is considered to play an important role in development of squamous-cell carcinoma (SCC), which is the most common esophageal cancer. Alcohol consumption and smoking, which can alter retinoic acid receptor levels, have been identified as key risk factors in the development of carcinoma in the aero-digestive tract. Therefore, the aim of the present study was to evaluate protein levels of retinoic acid receptors (i.e. RARα, β, γ, and RXRβ) in esophageal SCC and surrounding normal tissue of patients with untreated SCC and controls. Methods: All study participants completed a questionnaire concerning smoking and alcohol drinking habits as well as anthropometrical parameters. Protein levels of RARα, β, γ, and RXRβ were determined by Western Blot in normal esophageal tissue and tissue obtained from SCC of 21 patients with newly diagnosed esophageal SCC and normal esophageal tissue of 10 controls. Results: Protein levels of RARγ were significantly lower by ~68% in SCC compared to normal surrounding tissue in patients with SCC that smoked and/or consumed elevated amounts of alcohol. Furthermore, RARα protein levels were significantly lower (~- 45%) in SCC in comparison to normal esophageal mucosa in patients with elevated alcohol intake. When comparing protein levels of retinoic acid receptors between normal tissue of patients with SCC and controls, RARγ protein levels were found to be significantly higher (~2.7-fold) in normal esophageal tissue of SCC patients than in esophageal tissue obtained from controls. No differences were found for RARα, β, and RXRβ protein levels between normal esophageal tissue of patients and that of controls. Conclusion: In conclusion, results of the present study suggest that alterations of retinoic acid receptors protein may contribute in the development of SCC in esophagus and that in some patients life style (e.g. smoking and alcohol consumption) may be a critical component in the alteration of retinoic acid receptor levels in esophagus.

The role of c-kit and imatinib mesylate in uveal melanoma

Patricia Rusa Pereira — Wed,19 Oct 2005

Patricia Rusa Pereira, Alexandre Nakao Odashiro, Jean Claude Marshall, Zelia Maria Correa, Rubens Belfort Jr, Miguel N Burnier Jr

Journal of Carcinogenesis 2005 4(1):19-19

Background: Uveal melanoma (UM) is the most common primary intraocular tumor in adults, leading to metastasis in 40% of the cases and ultimately to death in 10 years, despite local and/or systemic treatment. The c-kit protein (CD117) is a membrane-bound tyrosine kinase receptor and its overexpression has been observed in several neoplasms. Imatinib mesylate is a FDA approved compound that inhibits tyrosine quinase receptors, as well as c-kit. Imatinib mesylate controls tumor growth in up to 85% of advanced gastrointestinal stromal tumors, a neoplasia resistant to conventional therapy. Methods: Fifty-five specimens of primary UM selected from the archives of the Ocular Pathology Laboratory, McGill University, Montreal, Canada, were immunostained for c-kit. All cells displaying distinct immunoreactivity were considered positive. Four human UM cell lines and 1 human uveal transformed melanocyte cell line were tested for i n vitro proliferation Assays (TOX-6) and invasion assay with imatinib mesylate (concentration of 10 μM). Results: The c-kit expression was positive in 78.2% of the UM. There was a statistical significant decrease in the proliferation and invasion rates of all 5 cell lines. Conclusion: The majority of UM expressed c-kit, and imatinib mesylate does decrease the proliferation and invasion rates of human UM cell lines. These results justify the need for a clinical trial to investigate in vivo the response of UM to imatinib mesylate.

Telomerase expression is sufficient for chromosomal integrity in cells lacking p53 dependent G 1 checkpoint function

Dennis A Simpson — Thu,6 Oct 2005

Dennis A Simpson, Elizabeth Livanos, Timothy P Heffernan, William K Kaufmann

Journal of Carcinogenesis 2005 4(1):18-18

Background: Secondary cultures of human fibroblasts display a finite lifespan ending at senescence. Loss of p53 function by mutation or viral oncogene expression bypasses senescence, allowing cell division to continue for an additional 10 - 20 doublings. During this time chromosomal aberrations seen in mitotic cells increase while DNA damage and decatenation checkpoint functions in G 2 cells decrease. Methods: To explore this complex interplay between chromosomal instability and checkpoint dysfunction, human fibroblast lines were derived that expressed HPV16E6 oncoprotein or dominant-negative alleles of p53 (A143V and H179Q) with or without the catalytic subunit of telomerase. Results: Cells with normal p53 function displayed 86 - 93% G 1 arrest after exposure to 1.5 Gy ionizing radiation (IR). Expression of HPV16E6 or p53-H179Q severely attenuated G 1 checkpoint function (3 - 20% arrest) while p53-A143V expression induced intermediate attenuation (55 - 57% arrest) irrespective of telomerase expression. All cell lines, regardless of telomerase expression or p53 status, exhibited a normal DNA damage G 2 checkpoint response following exposure to 1.5 Gy IR prior to the senescence checkpoint. As telomerase-negative cells bypassed senescence, the frequencies of chromosomal aberrations increased generally congruent with attenuation of G 2 checkpoint function. Telomerase expression allowed cells with defective p53 function to grow >175 doublings without chromosomal aberrations or attenuation of G 2 checkpoint function. Conclusion: Thus, chromosomal instability in cells with defective p53 function appears to depend upon telomere erosion not loss of the DNA damage induced G 1 checkpoint.

hTERT protein expression is independent of clinicopathological parameters and c-Myc protein expression in human breast cancer

AE Elkak — Tue,4 Oct 2005

AE Elkak, G Meligonis, M Salhab, B Mitchell, JRS Blake, RF Newbold, K Mokbel

Journal of Carcinogenesis 2005 4(1):17-17

Background: Telomerase is a ribonucleoprotein enzyme that synthesises telomeres after cell division and maintains chromosomal length and stability thus leading to cellular immortalisation. The hTERT (human telomerase reverse transcriptase) subunit seems to be the rate-limiting determinant of telomerase and knowledge of factors controlling hTERT transcription may be useful in therapeutic strategies. The hTERT promoter contains binding sites for c-Myc and there is some experimental and in vitro evidence that c-Myc may increase hTERT expression. We previously reported no correlation between c-Myc mRNA expression and hTERT mRNA or telomerase activity in human breast cancer. This study aims to examine the correlation between hTERT expression as determined by immunohistochemistry and c-Myc expression, lymph node status, and tumour size and grade in human breast cancer. Materials and methods: The immunohistochemical expression of hTERT and c-Myc was investigated in 38 malignant breast tumours. The expression of hTERT was then correlated with the lymph node status, c-Myc expression and other clinicopathological parameters of the tumours. Results: hTERT expression was positive in 27 (71%) of the 38 tumours. 15 (79%) of 19 node positive tumours were hTERT positive compared with 11 (63%) of 19 node negative tumours. The expression was higher in node positive tumours but this failed to reach statistical significance (p = 0.388). There was no significant association with tumour size, tumour grade or c-Myc expression. However, hTERT expression correlated positively with patients' age (correlation coefficient = 0.415, p = 0.0097). Conclusion: hTERT protein expression is independent of lymph node status, tumour size and grade and c-Myc protein expression in human breast cancer

Sulindac metabolites inhibit epidermal growth factor receptor activation and expression

Heather A Pangburn — Fri,2 Sep 2005

Heather A Pangburn, Hanna Kraus, Dennis J Ahnen, Pamela L Rice

Journal of Carcinogenesis 2005 4(1):16-16

Background: Regular use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a decreased mortality from colorectal cancer (CRC). NSAIDs induce apoptotic cell death in colon cancer cells in vitro and inhibit growth of neoplastic colonic mucosa in vivo however, the biochemical mechanisms required for these growth inhibitory effects are not well defined. We previously reported that metabolites of the NSAID sulindac downregulate extracellular-signal regulated kinase 1/2 (ERK1/2) signaling and that this effect is both necessary and sufficient for the apoptotic effects of these drugs. The goal of this project was to specifically test the hypothesis that sulindac metabolites block activation and/or expression of the epidermal growth factor (EGF) receptor (EGFR). Methods: HT29 human colon cancer cells were treated with EGF, alone, or in the presence of sulindac sulfide or sulindac sulfone. Cells lysates were assayed by immunoblotting for phosphorylated EGFR (pEGFR, pY1068), total EGFR, phosphorylated ERK1/2 (pERK1/2), total ERK1/2, activated caspase-3, and α-tubulin. Results: EGF treatment rapidly induced phosphorylation of both EGFR and ERK1/2 in HT29 colon cancer cells. Pretreatment with sulindac metabolites for 24 h blocked EGF-induced phosphorylation of both EGFR and ERK1/2 and decreased total EGFR protein expression. Under basal conditions, downregulation of pEGFR and total EGFR was detected as early as 12 h following sulindac sulfide treatment and persisted through at least 48 h. Sulindac sulfone induced downregulation of pEGFR and total EGFR was detected as early as 1 h and 24 h, respectively, following drug treatment, and persisted through at least 72 h. EGFR downregulation by sulindac metabolites was observed in three different CRC cell lines, occurred prior to the observed downregulation of pERK1/2 and induction of apoptosis by these drugs, and was not dependent of caspase activation. Conclusion: These results suggest that downregulation of EGFR signaling by sulindac metabolites may occur, at least in part, by inhibiting activation and expression of EGFR. Inhibition of EGFR signaling may account for part of the growth inhibitory and chemopreventive effects of these compounds.

Apoptosis induced by the Tibetan herbal remedy PADMA 28 in the T cell-derived lymphocytic leukaemia cell line CEM-C7H2

Marcel Jenny — Fri,2 Sep 2005

Marcel Jenny, Wolfgang Schwaiger, David Bernhard, Oliver A Wrulich, Daria Cosaceanu, Dietmar Fuchs, Florian Ueberall

Journal of Carcinogenesis 2005 4(1):15-15

The Tibetan herbal remedy PADMA 28 revealed promising results to support treatment of atherosclerosis, Charot syndrome (intermittent claudication), chronic active hepatitis and infection of the respiratory tract. The remedy was confirmed to be closely linked with anti- and pro-oxidative properties in vitro . In this study, apoptogenic and survival effects of PADMA 28 were investigated in the T cell-derived lymphocytic leukaemia cell line CEM-C7H2. PADMA 28 led to a concentration-dependent inhibition of cell proliferation accompanied by the accumulation of CEM-C7H2 cells in subG1 phase, fragmentation of poly (ADP-ribose) polymerase (PARP) and nuclear body formation. Treatment with PADMA 28 rescued to some extent cells over-expressing Bcl-2 from apoptosis. This finding suggests that the mechanism of action of PADMA 28 may be via interference with Bcl-2 triggered survival pathways.

Mucin phenotypic expression and p53 gene abnormality of gastric super-minute well-differentiated adenocarcinoma: Re-evaluation with relationship between histogenesis of well-differentiated adenocarcinoma and intestinal metaplasia in distal stomach

Ryo Wada — Thu,1 Sep 2005

Ryo Wada, Toshikazu Yamaguchi, Takayuki Tanizaki

Journal of Carcinogenesis 2005 4(1):14-14

Background: Although the gastric well-differentiated adenocarcinoma in the distal stomach has been thought to develop via a intestinal metaplasia-carcinoma sequence, there are some disproofs from new mucin examinations for minute-size lesions in same type carcinoma. The current study was performed and pointed out the new findings for the solution to the problem according to the point described above. Methods: 12 super-minute lesions (less than 1 mm in maximum diameter) of well-differentiated adenocarcinoma in distal stomach (SMCa), which were detected from the pathological examinations of 210 surgically resected stomach specimens, and the mucosa adjacent to these carcinoma lesions, were examined by immunohistochemical mucin stainings (MUC2 and CD-10: intestinal phenotype, 45M1 and MUC6: gastric phenotype) and p53-overexpression. And the analyses of the replication error of the microsatellites in chromosome 17 related p53 gene (TP53 and D17S786) (RER-p53MS) were performed in SMCa lesions, adjacent mucosa to each lesion and other gastric mucosa with intestinal metaplasia, because all SMCa lesions showed p53-overexpression immunohistochemically, decribed below. Results: 1. The carcinoma cells in all SMCa lesions were positive for 45M1 and p53. On the other hand, no positive carcinoma cells for MUC6 were seen although the pyloric glands and the remnant pyloric gland in the SMCa lesions in the same slides were positive for MUC6. Ten lesions (83%) had intestinal phenotypic mucin (10 lesions: MUC2 (+), 4 lesions: CD10 (+)). Two lesions (17%) were positive for only 45M1 (gastric phenotypic mucin). 2. All of the mucosa adjacent to SMCa showed intestinal metaplasia (complete type: 7 regions, incomplete type: 5 regions). 3. RER-p53MS was confirmed in 42% (5/12 regions) of SMCa, in 42% (5/12 regions) of the mucosa adjacent to SMCa and 14% (6/42 regions) of the other intestinal metaplasia mucosa. Conclusion: Most of the super-minute well-differentiated adenocarcinoma lesions in the distal stomach, which had both gastric and intestinal phenotypic mucin, are considered to develop from the tubular proliferative zone with the incomplete type of the intestinal metaplasia and p53 gene abnormality, while a part of them, which had only gastric phenotypic mucin, may derive from the gastric native tubules (non-metaplastic epithelium) with p53 gene abnormality.

Genetic polymorphisms in DPF3 associated with risk of breast cancer and lymph node metastases

Carolyn R Hoyal — Fri,19 Aug 2005

Carolyn R Hoyal, Stefan Kammerer, Richard B Roth, Richard Reneland, George Marnellos, Marion Kiechle, Ulrike Schwarz-Boeger, Lyn R Griffiths, Florian Ebner, Joachim Rehbock, Matthew R Nelson, Andreas Braun

Journal of Carcinogenesis 2005 4(1):13-13

Background: Several studies have identified rare genetic variations responsible for many cases of familial breast cancer but their contribution to total breast cancer incidence is relatively small. More common genetic variations with low penetrance have been postulated to account for a higher proportion of the population risk of breast cancer. Methods and Results: In an effort to identify genes that influence non-familial breast cancer risk, we tested over 25,000 single nucleotide polymorphisms (SNPs) located within approximately 14,000 genes in a large-scale case-control study in 254 German women with breast cancer and 268 age-matched women without malignant disease. We identified a marker on chromosome 14q24.3-q31.1 that was marginally associated with breast cancer status (OR = 1.5, P = 0.07). Genotypes for this SNP were also significantly associated with indicators of breast cancer severity, including presence of lymph node metastases ( P = 0.006) and earlier age of onset ( P = 0.01). The association with breast cancer status was replicated in two independent samples (OR = 1.35, P = 0.05). High-density association fine mapping showed that the association spanned about 80 kb of the zinc-finger gene DPF3 (also known as CERD4 ). One SNP in intron 1 was found to be more strongly associated with breast cancer status in all three sample collections (OR = 1.6, P = 0.003) as well as with increased lymph node metastases ( P = 0.01) and tumor size ( P = 0.01). Conclusion: Polymorphisms in the 5' region of DPF3 were associated with increased risk of breast cancer development, lymph node metastases, age of onset, and tumor size in women of European ancestry. This large-scale association study suggests that genetic variation in DPF3 contributes to breast cancer susceptibility and severity.

Characterization of insulin-like-growth factor II (IGF II) mRNA positive hepatic altered foci and IGF II expression in hepatocellular carcinoma during diethylnitrosamine-induced hepatocarcinogenesis in rats

Biswajit Mukherjee — Wed,10 Aug 2005

Biswajit Mukherjee, Shampa Ghosh, Tanushree Das, Manika Doloi

Journal of Carcinogenesis 2005 4(1):12-12

Background: Insulin-like-growth factor II (IGF II) has been implicated in the pathogenesis of neoplasm of different tissues, including liver of rats and men. This growth factor is believed to exert its effect during cellular proliferation. During the process of development of hepatocellular carcinoma (HCC), different hepatic altered foci appear. They are believed to be the putative precursors of HCC in rats and in men. Thus, to study the role of the gene in a defined model of hepatocarcinogenesis was the target to elucidate its role in various cancer phenotypes during the entire development stage of cancer, right from earlier preneoplastic lesions to HCC Methods: Antisense in situ hybridization technique was used here to characterize the type(s) of foci in which IGF II mRNA had expressed during the development of hepatocarcinogenesis-induced by diethylnitrosamine and promoted by phenobarbital in rats. Various focal lesions have been categorized depending on the stages and sizes along with IGF II expression patterns in them. Immunohistochemical detection for proliferating cell nuclear antigen (PCNA) was made to detect the role of the gene in preneoplastic and neoplastic cellular proliferation. Results: IGF II expression was located in the glycogen-storage acidophilic cell foci maximally followed by mixed cell lesions and the least in basophilic lesions. The expression of IGF II was found to be predominant in the HCC. The expression of gene was also located at the peripheral cells of spongiosis hepatis which are believed to be the precursor of ito cell carcinoma. It was noted that there is a direct correlation between IGF II expression and Immunohistochemical detection for PCNA. Conclusion: It may be concluded that IGF II gene expression plays an important role during the development of neoplasia and the gene expresses in the sequence of events leading from glycogen-rich-acidophilic lesions to glycogen poor basophilic lesions to HCC with an expression pattern of "high-low-high" in terms of degree of expression. Moreover, the essential role of the gene at the immediate initiation stage of carcinogenesis (first few weeks) and during HCC development cannot be ignored. Thus this expression can be used as a suitable marker for very early detection of the cancerous process and can save numbers of future cancer victims by very early detection of this disease.

Bystander effects in UV-induced genomic instability: Antioxidants inhibit delayed mutagenesis induced by ultraviolet A and B radiation

Jostein Dahle — Tue,9 Aug 2005

Jostein Dahle, Egil Kvam, Trond Stokke

Journal of Carcinogenesis 2005 4(1):11-11

Background: Genomic instability is characteristic of many types of human cancer. Recently, we reported that ultraviolet radiation induced elevated mutation rates and chromosomal instability for many cell generations after ultraviolet irradiation. The increased mutation rates of unstable cells may allow them to accumulate aberrations that subsequently lead to cancer. Ultraviolet A radiation, which primarily acts by oxidative stress, and ultraviolet B radiation, which initially acts by absorption in DNA and direct damage to DNA, both produced genomically unstable cell clones. In this study, we have determined the effect of antioxidants on induction of delayed mutations by ultraviolet radiation. Delayed mutations are indicative of genomic instability. Methods: Delayed mutations in the hypoxanthine phosphoribosyl transferase ( hprt ) gene were detected by incubating the cells in medium selectively killing hprt mutants for 8 days after irradiation, followed by a 5 day period in normal medium before determining mutation frequencies. Results: The UVB-induced delayed hprt mutations were strongly inhibited by the antioxidants catalase, reduced glutathione and superoxide dismutase, while only reduced glutathione had a significant effect on UVA-induced delayed mutations. Treatment with antioxidants had only minor effects on early mutation frequenies, except that reduced glutathione decreased the UVB-induced early mutation frequency by 24 %. Incubation with reduced glutathione was shown to significantly increase the intracellular amount of reduced glutathione. Conclusion: The strong effects of these antioxidants indicate that genomic instability, which is induced by the fundamentally different ultraviolet A and ultraviolet B radiation, is mediated by reactive oxygen species, including hydrogen peroxide and downstream products. However, cells take up neither catalase nor SOD, while incubation with glutathione resulted in increased intracellular levels of glutathione. Previously, we have shown that ultraviolet induced delayed mutations may be induced via a bystander effect and that this effect is 5-fold higher for UVB radiation than for UVA radiation. Therefore, we propose that the antioxidants inhibit an ultraviolet radiation-induced bystander effect and that the effect is transmitted via the medium and via an internal transfer between cells, like gap junctional intercellular communication, for UVB radiation and only by the latter mechanism for UVA radiation.

Differential regulation of somatostatin receptors 1 and 2 mRNA and protein expression by tamoxifen and estradiol in breast cancer cells

Juan A Rivera — Thu,14 Jul 2005

Juan A Rivera, Haydar Alturaihi, Ujendra Kumar

Journal of Carcinogenesis 2005 4(1):10-10

Somatostatin (SST) inhibition of hormone hypersecretion from tumors is mediated by somatostatin receptors (SSTRs). SSTRs also play an important role in controlling tumor growth through specific antiproliferative actions. These receptors are well expressed in numerous normal and tumor tissues and are susceptible to regulation by a variety of factors. Estradiol, a potent trophic and mitogenic hormone in its target tissues, is known to modulate the expression of SST and its receptors. Accordingly, in the present study, we determined the effects of tamoxifen, a selective estrogen receptor (ER) modulator (SERM), and estradiol on SSTR1 and SSTR2 expression at the mRNA and protein levels in ER-positive and -negative breast cancer cells. We found that SSTR1 was upregulated by tamoxifen in a dose-dependent manner but no effect was seen with estradiol. In contrast, SSTR2 was upregulated by both tamoxifen and estradiol. Combined treatment caused suppression of SSTR1 below control levels but had no significant effect on SSTR2. Treatment with SSTR1-specific agonist was significantly more effective in suppressing cell proliferation of cells pre-treated with tamoxifen. Taking these data into consideration, we suggest that tamoxifen and estradiol exert variable effects on SSTR1 and SSTR2 mRNA and protein expression and distributional pattern of the receptors. These changes are cell subtype-specific and affect the ability of SSTR agonists to inhibit cell proliferation.

Intercalated duct cell is starting point in development of pancreatic ductal carcinoma?

Ryo Wada — Thu,14 Jul 2005

Ryo Wada, Kaoru Ogawa, Toshikazu Yamaguchi, Takayuki Tanizaki, Michio Matsumoto

Journal of Carcinogenesis 2005 4(1):9-9

Background: Although it is well known that the pancreatic ductal carcinoma may develop having a relationship to the mucous gland hyperplasia (MGH) with atypia (PanIN-1B by PanIN system), the starting point of this atypical MGH is unclear. To know it, we examined the pancreas tissue using many methods described below. Methods: 1. Twenty-seven surgically resected pancreas tissue specimens, including pancreatic ductal carcinomas (PDC), chronic pancreatitis and normal pancreas, were investigated using immunohistochemical stainings for MUC1, MUC6, 45M1, Ki67 and p53. 2. DNA extraction and analysis of K-ras mutation at codon 12 using microdissection method: The paraffin blocks with 16 regions including the intercalated duct cell (IC) adjacant to the atypical MGH were prepared for DNA extraction. Mutation of K-ras codon 12 was analized and compared in enriched polymerase chain reaction-enzyme-linked minisequence assay (PCR-ELMA). Results: 1. In the normal pancreas, although no positive cell was seen in 45M1, p53, Ki67, the cytoplasm of IC were always positive for MUC1 and sometimes positive for MUC6. In the pancreas with fibrosis or inflammation, MGH was positive for MUC6 and 45M1. And atypical MGH was positive for MUC1, MUC6 and 45M1. Some IC adjacent to the atypical MGH was positive for Ki67 as well as atypical MGH. The carcinoma cells in all cases of PDC were diffusely positive for MUC1, 45M1, p53 and Ki67, and focally positive for MUC6. 2. In K-ras mutation, we examined the regions including IC adjacent to the atypical MGH, because the immunohistochemical apomucin stainings of these regions resembled those of PDC as decribed above. And K-ras mutation was confirmed in 12 of 16 regions (75%). All mutations were a single mutation, in 6 regions GTT was detected, in 4 regions GAT was detected and in 2 region AGT was detected. Conclusion: Some intercalated duct cell may be the starting point of the pancreatic ductal carcinoma, because the exhibitions of mucin expressions, Ki67, p53 and K-ras mutation in some intercalated duct cell resembled those of mucous gland hyperplasia or pancreatic ductal carcinoma.

HER-2/ neu and CD117 (c-kit) overexpression in patients with pesticide exposure and extensive stage small cell lung carcinoma (ESSCLC)

Anil Potti — Thu,9 Jun 2005

Anil Potti, Apar Kishor Ganti, Sascha A Tuchman, Kaley Sholes, Eric Langness, Vijay Koka, Michael Koch

Journal of Carcinogenesis 2005 4(1):8-8

Background: The rate of detection of HER-2/ neu and CD117 (c-kit) overexpression in small cell lung cancer (SCLC) has varied widely; between 5-35% and 21-70% respectively. Methods: To evaluate the relationship between pesticide exposure and HER-2/ neu and CD117 overexpression in extensive stage SCLC (ESSCLC), we identified patients with ESSCLC and assessed pesticide exposure using a predetermined questionnaire. An exposure index (hours/day x days/year x years) ≥ 2400 hours was considered as 'exposed.' HER-2/ neu overexpression was evaluated on archival tissue using the DAKO Hercep test, and CD117 testing was performed using immunohistochemistry (A4052 polyclonal antibody). Results: 193 ESSCLC patients were identified. Pesticide exposure data could be obtained on 174 patients (84 females and 109 males) with a mean age of 68.5 years. 53/174 (30.4%) revealed HER-2/ neu overexpression. 54/174 (31.03%) specimens showed CD117 overexpression by IHC. On multivariate analysis, HER-2/ neu overexpression was associated with diminished survival (p < 0.001). In comparison, CD117 expression did not have an adverse prognostic value (p = 0.025). 41/53 (77.4%) patients with HER-2/ neu overexpression and 47/121 (38.8%) patients without overexpression had exposure to pesticides (odds ratio: 5.38; p < 0.01). Among the cohort tested for CD117, 29/54 (53.7%) patients with CD117 overexpression and 59/120 (49.2%) patients without CD117 overexpression had pesticide exposure (odds ratio: 1.18; p = 0.12). Conclusion: Pesticide exposure affects HER-2/ neu but not CD117 overexpression. Future studies are needed to determine specific pesticide(s)/pesticide components that are responsible for HER-2/ neu overexpression in ESSCLC, and to validate our findings in other solid tumors that overexpress HER-2/ neu .

SYK expression in human breast cancer

AE Elkak — Wed,20 Apr 2005

AE Elkak, W AL Sarakbi, K Mokbel

Journal of Carcinogenesis 2005 4(1):7-7

Background: Syk (Splenic Tyrosine Kinase) is an intracellular receptor protein kinase involved in cell proliferation, differentiation and phagocytosis. It has been studied in T and B lymphocytes, NK cells and platelets. The strong expression of Syk in mammary gland prompted research into its potential role in mammary carcinogenesis. There have been very few studies about its role in breast cancer with conflicting results. This study aims to investigate the hypothesis that Syk expression is down-regulated in breast cancer compared with ANCT and the association between its expression and clinicopathological parameters. Materials and methods: mRNA was extracted from 48 breast cancer specimens. Relative Syk to ribosomal RNA expression was determined by RT-PCR and Taqman methodology. Mann-Whitney U test was used to examine the association between Syk expression in cancer and ANCT. Spearman's rank correlation test was used to examine the association between Syk expression in tumours and patients' age, tumour size, tumour grade, estrogen and progesterone receptor status, lymph node metastasis, vascular invasion and clinical outcome. Results: The median for the relative value of Syk expression was 0.17 and 0.18 (range: 0.12 - 0.56 and 0.0 - 1.77) for tumours and ANCT respectively. There was no significant association between Syk expression in cancers and ANCT (p= 0.598) nor between Syk expression in tumours and patients' age, tumour size, tumour grade, estrogen and progesterone receptor status, lymph node metastasis, vascular invasion or prognosis. Conclusion: This study shows that Syk mRNA expression does not seem to vary between breast tumours and ANCT. Furthermore, we observed no significant association between Syk expression and clinicopathological parameters.

Females with paired occurrence of cancers in the UADT and genital region have a higher frequency of either Glutathione S-transferase M1/T1 null genotype

Sameer G Jhavar — Thu,24 Mar 2005

Sameer G Jhavar, Rajiv Sarin, Supriya Chopra, Ashwin Kotnis, Rita Mulherkar, Roger A'Hern, Jai Prakash Agarwal, Shyam Kishore Shrivastava, Ketayun A Dinshaw

Journal of Carcinogenesis 2005 4(1):6-6

Upper Aero digestive Tract (UADT) is the commonest site for the development of second cancer in females after primary cervical cancer. Glutathione S-transferase ( GSTM1 and / or T1 ) null genotype modulates the risk of developing UADT cancer (primary as well as second cancer). The aim of this study was to evaluate the difference in GST null genotype frequencies in females with paired cancers in the UADT and genital region as compared to females with paired cancers in the UADT and non-genital region. Forty-nine females with a cancer in the UADT and another cancer (at all sites-genital and non-genital) were identified from a database of patients with multiple primary neoplasms and were analyzed for the GSTM1 and T1 genotype in addition to known factors such as age, tobacco habits, alcohol habits and family history of cancer. Frequencies of GSTM1 null, GSTT1 null, and either GSTM1/T1 null were higher in females with paired occurrence of cancer in the UADT and genital site (54%, 33% and 75% respectively) in comparison to females with paired occurrence of cancer in the UADT and non-genital sites (22%, 6% and 24% respectively). The significantly higher inherited frequency of either GSTM1 / T1 null genotype in females with a paired occurrence of cancers in UADT and genital region (p = 0.01), suggests that these females are more susceptible to damage by carcinogens as compared to females who have UADT cancers in association with cancers at non-genital sites.

Colonic Paneth cell metaplasia is pre-neoplastic condition of colonic cancer or not?

Ryo Wada — Sat,12 Feb 2005

Ryo Wada, Toshikazu Yamaguchi, Kenichi Tadokoro

Journal of Carcinogenesis 2005 4(1):5-5

Background: The carcinogenesis of colorectal cancer has been accepted by a model for a cascade of genetic alterations, named the adenoma-carcinoma sequence. In order to elucidate the carcinogenesis of the colorectal cancer more clearly, the genetic abnormalies of the non-neoplastic mucosal epithelium of the colon and rectum should be investigated. It has been speculated that colonic Paneth cell metaplasia (PaM) is one of the pre-neoplastic mucosa of colonic cancer. Therefore, we studied the propria mucosa of the right colon with PaM from the standpoints of the frequency of the K-ras codon 12 mutations (K-ras), which is initial genetic abnormality in colorectal cancer, and the loss of heterozygosity of microsatellite markers (LOH-MS), which has a relationship to development of colorectal cancer. Methods: Fifty-two regions with PaM histopathologically from 12 surgically resected right colon specimens were studied. DNA extraction of the colonic mucosa with PaM was obtained using a microdissection method, and the frequency of the K-ras of PaM was investigated by enriched polymerase chain reaction-enzyme linked mini-sequence assay, and the frequency of the LOH-MS (D2S123, D17S250 and D5S346) of PaM was examined by high resolution fluorescenced labeled PCR primers. Results: K-ras mutation was detected in fifteen regions among 52 PaM (28.9%). All mutations were a single mutation and GGT changed to AGT in eleven and GAT in four. LOH-MS were detected in twenty-one regions among 52 PaM (40.4%) (D2S123: 35.4%, 17/48 regions, D17S250: 13.7%, 7/51 regions, and D5S346: 0%, 0/52 regions). No K-ras mutations and LOH-MS were detected in the controls (Colorectal mucosa with no PaM). Conclusions: Colonic mucosa with Paneth cell metaplasia may be one of the pre-neoplastic mucosa in the development of the colonic epithelial neoplasia.

Mutagenicity testing with transgenic mice. Part II: Comparison with the mouse spot test

Ulrich Wahnschaffe — Thu,27 Jan 2005

Ulrich Wahnschaffe, Annette Bitsch, Janet Kielhorn, Inge Mangelsdorf

Journal of Carcinogenesis 2005 4(1):4-4

The mouse spot test, an in vivo mutation assay, has been used to assess a number of chemicals. It is at present the only in vivo mammalian test system capable of detecting somatic gene mutations according to OECD guidelines (OECD guideline 484). It is however rather insensitive, animal consuming and expensive type of test. More recently several assays using transgenic animals have been developed. From data in the literature, the present study compares the results of in vivo testing of over twenty chemicals using the mouse spot test and compares them with results from the two transgenic mouse models with the best data base available, the lacI model (commercially available as the Big Blue ® mouse), and the lacZ model (commercially available as the Muta™ Mouse). There was agreement in the results from the majority of substances. No differences were found in the predictability of the transgenic animal assays and the mouse spot test for carcinogenicity. However, from the limited data available, it seems that the transgenic mouse assay has several advantages over the mouse spot test and may be a suitable test system replacing the mouse spot test for detection of gene but not chromosome mutations in vivo .

Mutagenicity testing with transgenic mice. Part I: Comparison with the mouse bone marrow micronucleus test

U Wahnschaffe — Mon,17 Jan 2005

U Wahnschaffe, A Bitsch, J Kielhorn, I Mangelsdorf

Journal of Carcinogenesis 2005 4(1):3-3

As part of a larger literature study on transgenic animals in mutagenicity testing, test results from the transgenic mutagenicity assays ( lacI model; commercially available as the Big Blue ® mouse, and the lacZ model; commercially available as the Muta™Mouse), were compared with the results on the same substances in the more traditional mouse bone marrow micronucleus test. 39 substances were found which had been tested in the micronucleus assay and in the above transgenic mouse systems. Although, the transgenic animal mutation assay is not directly comparable with the micronucleus test, because different genetic endpoints are examined: chromosome aberration versus gene mutation, the results for the majority of substances were in agreement. Both test systems, the transgenic mouse assay and the mouse bone marrow micronucleus test, have advantages and they complement each other. However, the transgenic animal assay has some distinct advantages over the micronucleus test: it is not restricted to one target organ and detects systemic as well as local mutagenic effects.

Single nucleotide polymorphisms (SNPs) are inherited from parents and they measure heritable events

Kari Hemminki — Mon,17 Jan 2005

Kari Hemminki, Asta Forsti, Justo Lorenzo Bermejo

Journal of Carcinogenesis 2005 4(1):2-2

Single nucleotide polymorphisms (SNPs) are extensively used in case-control studies of practically all cancer types. They are used for the identification of inherited cancer susceptibility genes and those that may interact with environmental factors. However, being genetic markers, they are applicable only on heritable conditions, which is often a neglected fact. Based on the data in the nationwide Swedish Family-Cancer Database, we review familial risks for all main cancers and discuss the evidence for a heritable component in cancer. The available evidence is not conclusive but it is consistent in pointing to a minor heritable etiology in cancer, which will hamper the success of SNP-based association studies. Empirical familial risks should be used as guidance for the planning of SNP studies. We provide calculations for the assessment of familial risks for assumed allele frequencies and gene effects (odds ratios) for different modes of inheritance. Based on these data, we discuss the gene effects that could account for the unexplained proportion of familial breast and lung cancer. As a conclusion, we are concerned about the indiscriminate use of a genetic tool to cancers, which are mainly environmental in origin. We consider the likelihood of a successful application of SNPs in gene-environment studies small, unless established environmental risk factors are tested on proven candidate genes.

Estrogen, mitochondria, and growth of cancer and non-cancer cells

Quentin Felty — Sat,15 Jan 2005

Quentin Felty, Deodutta Roy

Journal of Carcinogenesis 2005 4(1):1-1

In this review, we discuss estrogen actions on mitochondrial function and the possible implications on cell growth. Mitochondria are important targets of estrogen action. Therefore, an in-depth analysis of interaction between estrogen and mitochondria; and mitochondrial signaling to nucleus are pertinent to the development of new therapy strategies for the treatment of estrogen-dependent diseases related to mitochondrial disorders, including cancer.

Nitrosative stress induces DNA strand breaks but not caspase mediated apoptosis in a lung cancer cell line

Brandon G Bentz — Thu,23 Dec 2004

Brandon G Bentz, Neal D Hammer, James A Radosevich, G Kenneth Haines

Journal of Carcinogenesis 2004 3(1):16-16

Background: Key steps crucial to the process of tumor progression are genomic instability and escape from apoptosis. Nitric oxide and its interrelated reactive intermediates (collectively denoted as NO X ) have been implicated in DNA damage and mutational events leading to cancer development, while also being implicated in the inhibition of apoptosis through S-nitrosation of key apoptotic enzymes. The purpose of this study was to explore the interrelationship between NO X -mediated DNA strand breaks (DSBs) and apoptosis in cultured tumor cell lines. Methods: Two well-characterized cell lines were exposed to increasing concentrations of exogenous NO X via donor compounds. Production of NO X was quantified by the Greiss reaction and spectrophotometery, and confirmed by nitrotyrosine immunostaining. DSBs were measured by the alkaline single-cell gel electrophoresis assay (the COMET assay), and correlated with cell viability by the MTT assay. Apoptosis was analyzed both by TUNEL staining and Annexin V/propidium iodine FACS. Finally, caspase enzymatic activity was measured using an in-vitro fluorogenic caspase assay. Results: Increases in DNA strand breaks in our tumor cells, but not in control fibroblasts, correlated with the concentration as well as rate of release of exogenously administered NO X . This increase in DSBs did not correlate with an increase in cell death or apoptosis in our tumor cell line. Finally, this lack of apoptosis was found to correlate with inhibition of caspase activity upon exposure to thiol- but not NONOate-based NO X donor compounds. Conclusions: Genotoxicity appears to be highly interrelated with both the concentration and kinetic delivery of NO X . Moreover, alterations in cell apoptosis can be seen as a consequence of the explicit mechanisms of NO X delivery. These findings lend credence to the hypothesis that NO X may play an important role in tumor progression, and underscores potential pitfalls which should be considered when developing NO X -based chemotherapeutic agents.

Comparative study of matrix metalloproteinase expression between African American and Caucasian Women

Jacquline A Mason — Fri,29 Oct 2004

Jacquline A Mason, Haile F Yancy, Kerrie Lashley, Marty Jett, Agnes A Day

Journal of Carcinogenesis 2004 3(1):15-15

To date there are 26 human matrix metalloproteinases (MMPs) which are classified according to their substrate specificity and structural similarities. The four major subgroups of MMPs are gelatinases, interstitial collagenases, stromelysins, and membrane-type matrix metalloproteinases (MT-MMPs). This study investigates the expression of 26 MMPs, which have been shown to play a role in cancer metastasis. Breast tissues and cell lines derived from African American patients and Caucasian patients were assayed to demonstrate alterations in the transcription of genes primarily responsible for degrading the extracellular matrix (ECM). The expression levels of the extracellular matrix and adhesion molecules were analyzed using the gene array technology. Steady state levels of mRNAs were validated by RT-PCR analysis. Total RNA was isolated from tissue and cell lines and used in the RT-PCR assays. From this data, differential expression of MMPs between 6 breast cancer cell lines and 2 non-cancer breast cell lines was demonstrated. We have performed an in vitro comparison of MMP expression and established differences in 12 MMPs (3, 7, 8, 9, 11-15, 23B, 26, and 28) expression between African American and Caucasian breast cell lines. Thus, evidence indicates that altered expression of MMPs may play a role in the aggressive phenotype seen in African American women.

Feeding of soy protein isolate to rats during pregnancy and lactation suppresses formation of aberrant crypt foci in their progeny's colons: interaction of diet with fetal alcohol exposure

Amanda L Linz — Fri,15 Oct 2004

Amanda L Linz, Rijin Xiao, James G Parker, Pippa M Simpson, Thomas M Badger, Frank A Simmen

Journal of Carcinogenesis 2004 3(1):14-14

Soy protein isolate (SPI) in the diet may inhibit colon tumorigenesis. We examined azoxymethane (AOM)-induced aberrant crypt foci (ACF) in male rats in relation to lifetime, pre-weaning, or post-weaning dietary exposure to SPI and also within the context of fetal alcohol exposure. Pregnant Sprague Dawley rats were fed AIN-93G diets containing casein (20%, the control diet) or SPI (20%) as the sole protein source starting on gestation day 4 (GD 4). Progeny were weaned on postnatal day (PND) 21 to the same diet as their dams and were fed this diet until termination of the experiment at PND 138. Rats received AOM on PND 89 and 96. Lifetime (GD 4 to PND 138) feeding of SPI led to reduced frequency of ACF with 4 or more crypts in the distal colon. Progeny of dams fed SPI only during pregnancy and lactation or progeny fed SPI only after weaning exhibited similarly reduced frequency of large ACF in distal colon. Number of epithelial cells, in the distal colon, undergoing apoptosis was unaffected by diet. SPI reduced weight gain and adiposity, but these were not correlated with fewer numbers of large ACF. Lifetime SPI exposure similarly inhibited development of large ACF in Sprague Dawley rats whose dams were exposed to ethanol during pregnancy. In summary, feeding of SPI to rat dams during pregnancy and lactation suppresses numbers of large ACF in their progeny, implying a long-term or permanent change elicited by the maternal diet. Moreover, results support the use of ACF as an intermediate endpoint for elucidating effects of SPI and its biochemical constituents in colon cancer prevention in rats.

On the emergence of multifocal cancers

Dominik Wodarz — Fri,1 Oct 2004

Dominik Wodarz, Yoh Iwasa, Natalia L Komarova

Journal of Carcinogenesis 2004 3(1):13-13

Several tumors can exist as multiple lesions within a tissue. The lesions may either arise independently, or they may be monoclonal. The importance of multiple lesions for tumor staging, progression, and treatment is subject to debate. Here we use mathematical models to analyze the emergence of multiple, clonally related lesions within a single tissue. We refer to them as multi-focal cancers. We find that multifocal cancers can arise through a dynamical interplay between tumor promoting and inhibiting factors. This requires that tumor promoters act locally, while tumor inhibitors act over a longer range. An example of such factors may be angiogenesis promoters and inhibitors. The model further suggests that multifocal cancers represent an intermediate stage in cancer progression as the tumor evolves away from inhibition and towards promotion. Different patterns of progression can be distinguished: (i) If tumor inhibition is strong, the initial growth occurs as a unifocal and self contained lesion; progression occurs through bifurcation of the lesion and this gives rise to multiple lesions. As the tumor continues to evolve and pushes the balance between inhibition and promotion further towards promotion, the multiple lesions eventually give rise to a single large mass which can invade the entire tissue. (ii) If tumor inhibition is weaker upon initiation, growth can occur as a single lesion without the occurrence of multiple lesions, until the entire tissue is invaded. The model suggests that the sum of the tumor sizes across all lesions is the best characteristic which correlates with the stage and metastatic potential of the tumor.

Inducible cytochrome P450 activities in renal glomerular mesangial cells: Biochemical basis for antagonistic interactions among nephrocarcinogenic polycyclic aromatic hydrocarbons

MH Falahatpisheh — Tue,17 Aug 2004

MH Falahatpisheh, JK Kerzee, RP Metz, KC Donnelly, KS Ramos

Journal of Carcinogenesis 2004 3(1):12-12

Background: Benzo(a)pyrene (BaP), anthracene (ANTH) and chrysene (CHRY) are polynuclear aromatic hydrocarbons (PAHs) implicated in renal toxicity and carcinogenesis. These PAHs elicit cell type-specific effects that help predict toxicity outcomes in vitro and in vivo . While BaP and ANTH selectively injure glomerular mesangial cells, and CHRY targets cortico-tubular epithelial cells, binary or ternary mixtures of these hydrocarbons markedly reduce the overall cytotoxic potential of individual hydrocarbons. Methods: To study the biochemical basis of these antagonistic interactions, renal glomerular mesangial cells were challenged with BaP alone (0.03 - 30 μM) or in the presence of ANTH (3 μM) or CHRY (3 μM) for 24 hr. Total RNA and protein will be harvested for Northern analysis and measurements of aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin-O-deethylase (EROD) activity, respectively, to evaluate cytochrome P450 mRNA and protein inducibility. Cellular hydrocarbon uptake and metabolic profiles of PAHs were analyzed by high performance liquid chromatography (HPLC). Results: Combined hydrocarbon treatments did not influence the cellular uptake of individual hydrocarbons. ANTH or CHRY strongly repressed BaP-inducible cytochrome P450 mRNA and protein expression, and markedly inhibited oxidative BaP metabolism. Conclusion: These findings indicate that antagonistic interactions among nephrocarcinogenic PAHs involve altered expression of cytochrome P450s that modulate bioactivation profiles and nephrotoxic/ nephrocarcinogenic potential.

Molecular signatures of cell cycle transcripts in the pathogenesis of Glial tumors

Anitha P Pillai — Thu,17 Jun 2004

Anitha P Pillai, Rabindra Narayan Bhattacharya, Vishnampet V Radhakrishnan, Moinak Banerjee

Journal of Carcinogenesis 2004 3(1):11-11

Background: Astrocytic brain tumors are among the most lethal and morbid tumors of adults, often occurring during the prime of life. These tumors form an interesting group of cancer to understand the molecular mechanism of pathogenesis. Histological grading of Astrocytoma based on WHO classification does not provide complete information on the proliferation potential and biological behavior of the tumors. It is known that cancer results from the disruption of the orderly regulated cycle of replication and division. In the present study, we made an attempt to identify the cell cycle signatures and their involvement in the clinical aggressiveness of gliomas. Methods: The variation in expression of various cell cycle genes was studied in different stages of glial tumor progression (low and high grades), and the results were compared with their corresponding expression levels in the normal brain tissue. Macroarray analysis was used for the purpose. Results: Macroarray analysis of 114 cell cycle genes in different grades of glioma indicated differential expression pattern in 34% of the gene transcripts, when compared to the normal tissue. Majority of the transcripts belong to the intracellular kinase networks, cell cycle regulating kinases, transcription factors and transcription activators. Conclusion: Based on the observation in the expression pattern in low grade and high grade gliomas, it can be suggested that the upregulation of cell cycle activators are seen as an early event in glioma; however, in malignancy it is not the cell cycle activators alone, which are involved in tumorigenesis. Understanding the molecular details of cell cycle regulation and checkpoint abnormalities in cancer could offer an insight into potential therapeutic strategies.

Therapy of murine squamous cell carcinomas with 2-difluoromethylornithine

Yan Chen — Wed,2 Jun 2004

Yan Chen, Juncai Hu, David Boorman, Andres Klein-Szanto, Thomas G O'Brien

Journal of Carcinogenesis 2004 3(1):10-10

Targeted overexpression of an ornithine decarboxylase (ODC) transgene to mouse skin (the K6/ODC mouse) significantly enhances susceptibility to carcinogenesis. While in most strain backgrounds the predominant tumor type resulting from initiation-promotion protocols is benign squamous papilloma, K6/ODC mice on a FVB/N background develop malignant squamous cell carcinomas (SCCs) rapidly and in high multiplicity after carcinogen treatment. We have investigated the utility of polyamine-based therapy against SCCs in this model using the ODC inhibitor 2-difluoromethylornithine delivered orally. At a 2% concentration in drinking water, DFMO caused rapid tumor regression, but in most cases, tumors eventually regrew rapidly even in the presence of DFMO. The tumors that regrew were spindle cell carcinomas, an aggressive undifferentiated variant of SCC. At 1% DFMO in the drinking water, tumors also responded rapidly, but tumor regrowth did not occur. The majority of DFMO-treated SCCs were classified as complete responses, and in some cases, apparent tumor cures were achieved. The enzymatic activity of ODC, the target of DFMO, was substantially reduced after treatment with 1% DFMO and the high SCC polyamine levels, especially putrescine, were also significantly lowered. Based on the results of BrdUrd labeling and TUNEL assays, the effect of DFMO on SCC growth was accompanied by a significant reduction in tumor proliferation with no increase in the apoptotic index. These results demonstrate that SCCs, at least in the mouse, are particularly sensitive to polyamine-based therapy.

Correlation between thyroid hormone status and hepatic hyperplasia and hypertrophy caused by the peroxisome proliferator-activated receptor alpha agonist Wy-14,643

C Wang — Mon,24 May 2004

C Wang, J Youssef, ML Cunningham, M Badr

Journal of Carcinogenesis 2004 3(1):9-9

Background: The metabolic inhibitor rotenone inhibits hepatocellular proliferation and the incidence of liver cancer resulting from exposure to the PPARα agonist Wy-14,643, via unknown mechanisms. Since the absence of thyroid hormones diminishes hepatomegaly, an early biomarker for the hepatocarcinogenicity induced by PPARα agonists, this study was undertaken to investigate whether rotenone might interference with the ability of Wy-14,643 to alter the animal thyroid status. Methods: Male B6C3F1 mice were given Wy-14,643 (100 ppm), rotenone (600 ppm) or a mixture of both, in the feed for 7 days. Bromodeoxyuridine (BrDU), marker of cell replication, was delivered through subcutaneously implanted osmotic mini-pumps. At the end of the experiment, sera were collected and corticosterone and thyroid hormone levels were measured by solid-phase radioimmunoassay kits. In addition, liver tissue samples were stained immunohistochemically for BrDU to determine percentages of labeled cells. Further, cell surface area was determined from images generated by a Zeiss Axioplan microscope equipped with a plan Neofluar x40 0.75 na objective. Tracings of individual hepatocyte perimeters were then analyzed and cell-surface areas were calculated using MicroMeasure FL-4000. Results: Wy-14,643 caused a significant increase in liver weights, hepatocyte BrDU labeling index (LI), and hepatocyte surface area. In animals which received both Wy-14,643 and rotenone simultaneously, all of these effects were significantly less pronounced compared with mice that received Wy-14,643 alone. Rotenone alone decreased liver weights, LI and surface area. The Free Thyroid Index (FTI), which provides an accurate reflection of the animal's thyroid status, was 5.0 ± 0.3 in control mice. In animals exposed to rotenone, these values decreased to 2.0 ± 0.9, but in animals which received Wy-14,643, levels increased significantly to 7.7 ± 0.9. FTI values decreased to 3.4 ± 0.8 in mice receiving both rotenone and Wy-14,643. Conclusion: A strong correlation was observed between the animal thyroid status and both, hepatocyte proliferation (r 2 = 0.62), and hepatocyte surface area (r 2 = 0.83). These results support the hypothesis that the thyroid status of the animal plays a role in PPARα-induced hepatocellular proliferation and liver cell enlargement. Both these events are known to contribute to the expression of liver cancer in response to the activation of PPARα.

Time- and dose-dependent effects of curcumin on gene expression in human colon cancer cells

Marjan J Van Erk — Wed,12 May 2004

Marjan J Van Erk, Eva Teuling, Yvonne CM Staal, Sylvie Huybers, Peter J Van Bladeren, Jac MMJG Aarts, Ben van Ommen

Journal of Carcinogenesis 2004 3(1):8-8

Background: Curcumin is a spice and a coloring food compound with a promising role in colon cancer prevention. Curcumin protects against development of colon tumors in rats treated with a colon carcinogen, in colon cancer cells curcumin can inhibit cell proliferation and induce apoptosis, it is an anti-oxidant and it can act as an anti-inflammatory agent. The aim of this study was to elucidate mechanisms and effect of curcumin in colon cancer cells using gene expression profiling. Methods: Gene expression changes in response to curcumin exposure were studied in two human colon cancer cell lines, using cDNA microarrays with four thousand human genes. HT29 cells were exposed to two different concentrations of curcumin and gene expression changes were followed in time (3, 6, 12, 24 and 48 hours). Gene expression changes after short-term exposure (3 or 6 hours) to curcumin were also studied in a second cell type, Caco-2 cells. Results: Gene expression changes (>1.5-fold) were found at all time points. HT29 cells were more sensitive to curcumin than Caco-2 cells. Early response genes were involved in cell cycle, signal transduction, DNA repair, gene transcription, cell adhesion and xenobiotic metabolism. In HT29 cells curcumin modulated a number of cell cycle genes of which several have a role in transition through the G2/M phase. This corresponded to a cell cycle arrest in the G2/M phase as was observed by flow cytometry. Functional groups with a similar expression profile included genes involved in phase-II metabolism that were induced by curcumin after 12 and 24 hours. Expression of some cytochrome P450 genes was downregulated by curcumin in HT29 and Caco-2 cells. In addition, curcumin affected expression of metallothionein genes, tubulin genes, p53 and other genes involved in colon carcinogenesis. Conclusions: This study has extended knowledge on pathways or processes already reported to be affected by curcumin (cell cycle arrest, phase-II genes). Moreover, potential new leads to genes and pathways that could play a role in colon cancer prevention by curcumin were identified.

Mutagenicity of the peroxisome proliferators clofibrate, Wyeth 14,643 and di-2-ethylhexyl phthalate in the lacZ plasmid-based transgenic mouse mutation assay

Michael ETI Boerrigter — Wed,5 May 2004

Michael ETI Boerrigter

Journal of Carcinogenesis 2004 3(1):7-7

Background: Peroxisome proliferators are considered rodent carcinogens that are putative human non-carcinogens based on the presumed absence of direct genetic toxicity in rodent and human cells and the resistance of human cells to the induction of peroxisomes by peroxisome proliferators. The highly sensitive lacZ plasmid-based transgenic mouse mutation assay was employed to investigate the mutagenicity of several peroxisome proliferators based on several lines of evidence suggesting that these agents may in fact exert a genotoxic effect. Methods: Male and female lacZ -plasmid based transgenic mice were treated at 4 months of age with 6 doses of 2,333 mg di-2-ethylhexyl phthalate (DHEP), 200 mg Wyeth-14,643, or 90 mg clofibrate per kg of bodyweight, respectively, over a two-week period. Control animals were treated with the respective vehicles only (35% propyl glycol for DEHP and Wyeth-14,643 treatment controls and sterile water for clofibrate treatment controls). The mutant frequency in liver, kidney and spleen DNA was determined as the proportion of retrieved mutant and wild-type lacZ plasmids expressed in Escherichia Coli C host cells employing a positive selection system for mutant plasmids. Results: Exposure to DEHP or Wyeth-14,643 significantly increased the mutant frequency in liver, but not in kidney or spleen, of both female and male mice. Treatment with clofibrate did not lead to an increased mutant frequency in any of the organs studied. Conclusion: The results indicate that some peroxisome proliferators display an organ-specific mutagenicity in lacZ plasmid-based transgenic mice consistent with historical observations of organ- and compound-specific carcinogenicity.

Constitutive activation of the Ras-Raf signaling pathway in metastatic melanoma is associated with poor prognosis

Roland Houben — Fri,26 Mar 2004

Roland Houben, Jurgen C Becker, Andreas Kappel, Patrick Terheyden, Eva-B Brocker, Rudolf Goetz, Ulf R Rapp

Journal of Carcinogenesis 2004 3(1):6-6

Background: Genes of the Raf family encode kinases that are regulated by Ras and mediate cellular responses to growth signals. Recently, it was shown that activating mutations of BRaf are found with high frequency in human melanomas. The Ras family member most often mutated in melanoma is NRas. Methods: The constitutive activation of the Ras/Raf signaling pathway suggests an impact on the clinical course of the tumor. To address this notion, we analyzed tumor DNA from 114 primary cutaneous melanomas and of 86 metastatic lesions obtained from 174 patients for mutations in BRaf (exons 15 and 11) and NRas (exons 1 and 2) by direct sequencing of PCR products and correlated these results with the clinical course. Results: In 57.5% of the tumors either BRaf or NRas were mutated with a higher incidence in metastatic (66.3%) than in primary lesions (50.9%). Although the majority of BRaf mutations affected codon 599, almost 15% of mutations at this position were different from the well-described exchange from valine to glutamic acid. These mutations (V599R and V599K) also displayed increased kinase and transforming activity. Surprisingly, the additional BRaf variants D593V, G465R and G465E showed a complete loss of activity in the in vitro kinase assay; however, cells overexpressing these mutants displayed increased Erk phosphorylation. The correlation of mutational status and clinical course revealed that the presence of BRaf/NRas mutations in primary tumors did not negatively impact progression free or overall survival. In contrast, however, for metastatic lesions the presence of BRAF/NRAS mutations was associated with a significantly poorer prognosis, i.e. a shortened survival. Conclusion: We demonstrate a high - albeit lower than initially anticipated - frequency of activating BRaf mutations in melanoma in the largest series of directly analyzed tumors reported to date. Notably, the clinical course of patients harboring activating BRaf mutations in metastatic melanoma was significantly affected by the presence of a constitutive BRaf activation in these.

In vitro cytogenetic testing of an organoselenium compound and its sulfur analogue in cultured rat bone marrow cells

Jacob H Jacob — Mon,15 Mar 2004

Jacob H Jacob, Ahmad M Khalil, Ahmed O Maslat

Journal of Carcinogenesis 2004 3(1):5-5

Background: Selenium (Se) is a non-metal element, occurring in varying degrees in the environment and it has been found to be a component of several enzymes. Different selenium compounds have been associated with carcinogenicity, toxicity, modification of metal toxicity and prevention of cancer. Organoselenium compounds had substantially greater bioavailability and less toxicity than that of inorganic selenium. From a chemical point of view, Se resembles sulfur (S) in many of its properties, thus, Se and S may be considered to be isosteric. The ability of a synthetic organoselenium compound; cyclopenta-dienyldicarbonyl ironselenoterephthalic acid (CSe) and its sulfur analogue (CS) in the range of 10 -8 to 10 -5 M, to induce sister-chormatid exchanges (SCE) and alter cell division expressed as mitotic index (MI) as well as cell survival has been investigated. Methods: Rat bone marrow cells were cultured in the presence of CSe and CS in the range of 10 -8 to 10 -5 M with a total exposure time of 4, 16 or 28 h at 37°C. Fluorescence-plus-Giemsa (FPG) technique was used to visualize chromosomes for SCE analysis and MI determination. Trypan blue exclusion technique was used to determine cell viability. Results: At the three exposure times, cell survival progressively decreased with increasing concentration, but the effect of either chemical was not significant (ANOVA; P < 0.05) as compared to the negative control. Significant reductions in MI were calculated at the highest concentration (10 -5 M) when either chemical was applied for 16 or 28 h. Furthermore, the mean SCE increased with longer exposure times and, in general, CSe had slightly greater effect on cell survival and caused higher frequencies of SCE than CS. The exception was the 10 -8 M treatment. However, both CSe and CS failed to induce 2-fold SCE as that of the negative control and therefore they are not considered as mutagens. Conclusion: Both CSe and CS in the range of 10 -8 to 10 -5 M could not double the SCE rate of the negative control and therefore not considered as mutagens at these experimental conditions.

Somatic mutations in stilbene estrogen-induced Syrian hamster kidney tumors identified by DNA fingerprinting

Kamaleshwar P Singh — Fri,5 Mar 2004

Kamaleshwar P Singh, Deodutta Roy

Journal of Carcinogenesis 2004 3(1):4-4

Kidney tumors from stilbene estrogen (diethylstilbestrol)-treated Syrian hamsters were screened for somatic genetic alterations by Random Amplified Polymorphic DNA-polymerase chain-reaction (RAPD-PCR) fingerprinting. Fingerprints from tumor tissue were generated by single arbitrary primers and compared with fingerprints for normal tissue from the same animal, as well as normal and tumor tissues from different animals. Sixty one of the arbitrary primers amplified 365 loci that contain approximately 476 kbp of the hamster genome. Among these amplified DNA fragments, 44 loci exhibited either qualitative or quantitative differences between the tumor tissues and normal kidney tissues. RAPD-PCR loci showing decreased and increased intensities in tumor tissue DNA relative to control DNA indicate that loci have undergone allelic losses and gains, respectively, in the stilbene estrogen-induced tumor cell genome. The presence or absence of the amplified DNA fragments indicate homozygous insertions or deletions in the kidney tumor DNA compared to the age-matched normal kidney tissue DNA. Seven of 44 mutated loci also were present in the kidney tissues adjacent to tumors (free of macroscopic tumors). The presence of mutated loci in uninvolved (non-tumor) surrounding tissue adjacent to tumors from stilbene estrogen-treated hamsters suggests that these mutations occurred in the early stages of carcinogenesis. The cloning and sequencing of RAPD amplified loci revealed that one mutated locus had significant sequence similarity with the hamster Cyp1A1 gene. The results show the ability of RAPD-PCR to detect and isolate, in a single step, DNA sequences representing genetic alterations in stilbene estrogen-induced cancer cells, including losses of heterozygosity, and homozygous deletion and insertion mutations. RAPD-PCR provides an alternative molecular approach for studying cancer cytogenetics in stilbene estrogen-induced tumors in humans and experimental models. Although the exact functional importance of mutated loci is unknown, this study indicates that these altered loci may participate during tumor progression in the kidney.

To eat or not to eat: The NICE way

Gopala Kovvali — Thu,26 Feb 2004

Gopala Kovvali

Journal of Carcinogenesis 2004 3(1):3-3

Analysis of in vivo and in vitro DNA strand breaks from trihalomethane exposure

David R Geter — Tue,17 Feb 2004

David R Geter, Lina W Chang, Nancy M Hanley, Matthew K Ross, Rex A Pegram, Anthony B DeAngelo

Journal of Carcinogenesis 2004 3(1):2-2

Background: Epidemiological studies have linked the consumption of chlorinated surface waters to an increased risk of two major causes of human mortality, colorectal and bladder cancer. Trihalomethanes (THMs) are by-products formed when chlorine is used to disinfect drinking water. The purpose of this study was to examine the ability of the THMs, trichloromethane (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), and tribromomethane (TBM), to induce DNA strand breaks (SB) in (1) CCRF-CEM human lymphoblastic leukemia cells, (2) primary rat hepatocytes (PRH) exposed in vitro, and (3) rats exposed by gavage or drinking water. Methods: DNA SB were measured by the DNA alkaline unwinding assay (DAUA). CCRF-CEM cells were exposed to individual THMs for 2 hr. Half of the cells were immediately analyzed for DNA SB and half were transferred into fresh culture medium and incubated for an additional 22 hr before testing for DNA SB. PRH were exposed to individual THMs for 4 hr then assayed for DNA SB. F344/N rats were exposed to individual THMs for 4 hr, 2 weeks, and to BDCM for 5 wk then tested for DNA SB. Results: CCRF-CEM cells exposed to 5- or 10-mM brominated THMs for 2 hr produced DNA SB. The order of activity was TBM>DBCM>BDCM; TCM was inactive. Following a 22-hr recovery period, all groups had fewer SB except 10-mM DBCM and 1-mM TBM. CCRF-CEM cells were found to be positive for the GSTT1-1 gene, however no activity was detected. No DNA SB, unassociated with cytotoxicity, were observed in PRH or F344/N rats exposed to individual THMs. Conclusion: CCRF-CEM cells exposed to the brominated THMs at 5 or 10 mM for 2 hr showed a significant increase in DNA SB when compared to control cells. Additionally, CCRF-CEM cells exposed to DBCM and TBM appeared to have compromised DNA repair capacity as demonstrated by an increased amount of DNA SB at 22 hr following exposure. CCRF-CEM cells were found to be positive for the GSTT1-1 gene, however no activity was detected. No DNA SB were observed in PRH or F344/N rats exposed to individual THMs.

The mRNA expression of hTERT in human breast carcinomas correlates with VEGF expression

Katharine L Kirkpatrick — Thu,22 Jan 2004

Katharine L Kirkpatrick, Robert F Newbold, Kefah Mokbel

Journal of Carcinogenesis 2004 3(1):1-1

Background: Telomerase is a ribonucleoprotein enzyme that synthesises telomeres after cell division and maintains chromosomal stability leading to cellular immortalisation. hTERT (human telomerase reverse transcriptase) is the rate-limiting determinant of telomerase reactivation. Telomerase has been associated with negative prognostic indicators in some studies. The present study aims to detect any correlation between hTERT and the negative prognostic indicators VEGF and PCNA by quantitatively measuring the mRNA expression of these genes in human breast cancer and in adjacent non-cancerous tissue (ANCT). Materials and methods: RNA was extracted from 38 breast carcinomas and 40 ANCT. hTERT and VEGF165, VEGF189 and PCNA mRNA expressions were estimated by reverse transcriptase-PCR (RT-PCR) and Taqman methodology. Results: The level of expression of VEGF-165 and PCNA was significantly higher in carcinoma tissue than ANCT (p = 0.02). The ratio of VEGF165/189 expression was significantly higher in breast carcinoma than ANCT (p = 0.025). hTERT mRNA expression correlated with VEGF-189 mRNA (p = 0.008) and VEGF165 (p = 0.07). Conclusions: hTERT mRNA expression is associated with the expression of the VEGF189 and 165 isoforms. This could explain the poorer prognosis reported in breast tumours expressing high levels of hTERT. The relative expression of the VEGF isoforms is significantly different in breast tumour to ANCT, and this may be important in breast carcinogenesis.

Cancer: A single disease with a multitude of manifestions?

Peter Grandics — Tue,18 Nov 2003

Peter Grandics

Journal of Carcinogenesis 2003 2(1):9-9

The relationships of critical nutrients such as plant phenolics, vitamins, minerals and lipids are considered with respect to the incidence of a variety of cancers, and analyzed in terms of how these nutrient deficiencies alter immune function, DNA integrity and cell proliferation. With a significant correlation found between cancer and these nutrient deficiencies, the hypothesis is presented here that nutrition could provide a unifying perception of cancer and recast it as a single disease. This further suggests that a coordinated administration of specific, critical nutrients to cancer patients could lead to the reversal of the disease. It is also proposed that the concurrent presence of a variety of nutritional deficiencies in cancer patients requires a multilevel, systemic approach to this disease as opposed to the single active therapeutic agent approach that is the cornerstone of contemporary research and pharmacology.

Immunohistochemical determination of HER-2/neu overexpression in malignant melanoma reveals no prognostic value, while c-Kit (CD117) overexpression exhibits potential therapeutic implications

Anil Potti — Sun,16 Nov 2003

Anil Potti, Rachel C Hille, Michael Koch

Journal of Carcinogenesis 2003 2(1):8-8

Background: HER-2/neu and c-kit (CD117) onco-protein are increasingly being recognized as targets for therapy in solid tumors, but data on their role in malignant melanoma is currently limited. We studied the prevalence of overexpression of HER-2/neu and c-Kit in 202 patients with malignant melanoma to evaluate a possible prognostic value of these molecular targets in malignant melanoma. Methods: Overexpression of HER-2/neu and c-Kit was evaluated using immunohistochemical assays in 202 archival tissue specimens. Results: Between 1991 and 2001, 202 subjects (109 males; 54% and 93 females; 46%) with malignant melanoma were studied with a mean age of 57 years (age range: 15-101 years). The most common histologic type was amelanotic melanoma (n = 62; 30.7%) followed by superficial spreading melanoma (n = 54; 26.7%). The depth of penetration of melanoma (Breslow thickness, pT Stage) ranged from 0.4 mm (stage pT1) to 8.0 mm (stage pT4A). Mean thickness was 2.6 mm (stage pT3A). The ECOG performance scores ranged from 0 to 3. Only 2 patients (0.9%) revealed HER-2/neu overexpression, whereas 46 (22.8%) revealed c-Kit overexpression. Multivariate analysis performed did not show a significant difference in survival between c-Kit positive and negative groups (p = 0.36). Interestingly, not only was c-Kit more likely to be overexpressed in the superficial spreading type, a preliminary association between the presence or absence of c-Kit overexpression and the existence of another second primary tumor was also observed. Conclusions: The results of our large study indicate that the HER-2/neu onco-protein neither has a role in melanogenesis nor is a potential target for clinical trials with monoclonal antibody therapy. This indicates there is no role for its testing in patients with malignant melanoma. Although c-Kit, expressed preferentially in the superficial spreading type, may not have prognostic value, it does have significant therapeutic implications as a molecular target warranting further investigation.

Polymorphisms of the BRAF gene predispose males to malignant melanoma

Peter Meyer — Fri,14 Nov 2003

Peter Meyer, Consolato Sergi, Claus Garbe

Journal of Carcinogenesis 2003 2(1):7-7

The incidence of malignant melanoma has rapidly increased in recent years. Evidence points to the role of inheritance in melanoma development, but specific genetic risk factors are not well understood. Recent reports indicate a high prevalence of somatic mutations of the BRAF gene in melanomas and melanocytic nevi. Here we report that germ-line single nucleotide polymorphisms (SNPs) in BRAF are significantly associated with melanoma in German males, but not females. At-risk haplotypes of BRAF are shown. Based upon their frequencies, we estimate that BRAF could account for a proportion attributable risk of developing melanoma of 4% in the German population. The causal variant has yet to be determined. The burden of disease associated with this variant is greater than that associated with the major melanoma susceptibility locus C DKN2A , which has an estimated attributable risk of less than 1%.

Protection against diethylnitrosoamine-induced hepatocarcinogenesis by an indigenous medicine comprised of Nigella sativa, Hemidesmus indicus and Smilax glabra : a preliminary study

Samantha S Iddamaldeniya — Sat,18 Oct 2003

Samantha S Iddamaldeniya, Nalinie Wickramasinghe, Ira Thabrew, Neelakanthi Ratnatunge, Mayuri G Thammitiyagodage

Journal of Carcinogenesis 2003 2(1):6-6

Background: A decoction comprised of Nigella sativa seeds, Hemidesmus indicus root and Smilax glabra rhizome is used to treat cancer patients in Sri Lanka. However, the anti-carcinogenic properties of this decoction have not been experimentally confirmed. The purpose of this study was to determine whether the above decoction could protect against chemically induce hepatocarcinogenesis. Methods: The effects of this decoction on diethylnitrosamine (DEN) induced hepatocarcinogenesis were examined in male Wistar rats using the medium term bioassay system of Ito, based on a 2-step model of hepatocarcinogenesis. Rats were randomly divided into 6 groups of 10 each. Groups 1 to 4 were injected with DEN (200 mg/kg) to initiate carcinogenesis. Twenty-four hours later groups 1 and 2 were administered the decoction at 4 g/kg body weight/day (dose 1) and 6 g/kg body weight/day (dose 2), respectively. Group 3 and group 4 were given distilled water instead of the decoction and a suspension of garlic powder (20 g/kg body weight/day) in distilled water (positive control), respectively. Group 5 and 6 were injected with normal saline and twenty-four hours later group 5 was given distilled water (normal control) while group 6 was given decoction dose 2 (decoction control). Oral feeding continued for two weeks after which all rats were subjected to 2/3 partial hepatectomy to promote carcinogenesis. Oral feeding continued for eight more weeks. At the end of the 10th week, rats were sacrificed and samples of livers taken for immunohistochemical studies. Carcinogenic potential was scored by comparing the number, area and staining intensity of glutathione S-transferase placental form (GST-P) positive foci and the number of cells/cm 2 of the positive foci in the livers of the six groups of rats. Results: The number and area of DEN-mediated GST-P positive foci, number of cells/cm 2 of foci and staining intensity of the foci were significantly (P > 0.001) reduced by the decoction and garlic in the order dose 2 = garlic >dose 1. Conclusion: Overall results indicate that the decoction comprised of N. sativa , S. glabra and H. indicus has the potential to protect rat liver against DEN induced hepatocarcinogenesis

BRCA1/2 mutation screening and LOH analysis of lung adenocarcinoma tissue in a multiple-cancer patient with a strong family history of breast cancer

Melanie Barbara Boettger — Thu,2 Oct 2003

Melanie Barbara Boettger, Consolato Sergi, Peter Meyer

Journal of Carcinogenesis 2003 2(1):5-5

Background: Germline mutations in BRCA1/2 greatly elevate risks of breast and ovarian cancers, but the role of these genes in tumourigenesis of other cancer types is still being investigated. Objective: We report on an investigation of BRCA1/2 mutations and their loss of heterozygosity (LOH) in a patient with a strong family history of breast cancer who was diagnosed with consecutive primary cervical, ovarian and lung carcinomas. Methods and Results: BRCA1/2 mutation screening of the proband revealed a common familial breast- and ovarian cancer-associated germline BRCA2 mutation (3034del4bp). We then performed LOH analysis for BRCA2 in lung adenocarcinoma tissue of the patient. Using the laser-capture microdissection (LCM) technique, we obtained pure populations of neoplastic cells from which DNA could be extracted. Mutation analysis by denaturing high-performance liquid chromatography (DHPLC) and direct sequencing revealed loss of the mutant allele in the adenocarcinoma tumour tissue. Conclusion: To our knowledge, this is the first report of investigation for LOH for BRCA2 in primary lung adenocarcinoma tissue of a patient with multiple primary tumours related to a familial germline BRCA2 mutation. Interestingly, it was the mutant, not the wild-type, allele which was lost in the lung adenocarcinoma tissue.

Prevalence of pesticide exposure in young males (≤50 years) with adenocarcinoma of the prostate

Anil Potti — Tue,15 Jul 2003

Anil Potti, Amit W Panwalkar, Eric Langness

Journal of Carcinogenesis 2003 2(1):4-4

Evidence implicating pesticides as causative agents of prostate cancer is controversial, and specifically, data in young adults is lacking. Hence, we performed a preliminary study evaluating the relationship between pesticide exposure and prostate cancer in young males. After approval from the University of North Dakota Institutional Review Board and Human Subjects Committee, a retrospective study was performed on all young males (2400 hours were considered as 'exposed.' The 2400 hour cut-off value was chosen on the basis of previous reports indicating that this figure represents heavy exposure to genotoxic agents. Statistical analysis was obtained using SPSS-10 ® . Between 1991 and 2001, 61 young males with adenocarcinoma of the prostate were identified, of whom 56 patients with a mean age of 47 years (range: 40-49) had complete records of treatment and could be contacted for completion of the questionnaire. The most common stage at presentation was Stage III and the mean Gleason's score was 7.5 (range 5-9). Interestingly, almost a third (16/56, 28.6%) of patients had stage IV disease at presentation. 37/56 (66.1%) patients had 'significant' exposure in our study. In addition, interestingly, the mean survival in the subgroup of patients with pesticide exposure was 11.3 months (SD: +/- 2.3 months), while the mean survival in the patients without pesticide exposure (n = 19) was 20.1 months (SD: +/- 3.1 months), with p-value <0.01. Although our study is relatively small, it does reveal preliminary evidence linking pesticide exposure to the early development of, possibly aggressive, prostate adenocarcinoma. Future, larger, epidemiological studies are needed to confirm the findings of our study.

Ethnic differences in allelic distribution of IFN-g in South African women but no link with cervical cancer

Vandana A Govan — Fri,16 May 2003

Vandana A Govan, Henri RO Carrara, Johnny A Sachs, Margaret Hoffman, Grazyna A Stanczuk, Anna-Lise Williamson

Journal of Carcinogenesis 2003 2(1):3-3

Background: The failure of specific types of human papillomaviruses (HPV) to raise effective immune responses may be important in the pathogenesis of cervical cancer, the second most common cancer in South African women. Polymorphisms of a number of cytokine genes have been implicated in inducing susceptibility or resistance to cancers caused by infectious agents owing to their role in determining host immune response. Polymorphisms of IL-10 and IFN-γ genes are believed to influence the expression and/or secretion levels of their respective cytokines. Methods and Results: In this study, women with histologically proven cancer of the cervix (n = 458) and hospital-based controls (n = 587) were investigated for bi-allelic -1082 (A/G) polymorphisms of IL-10 and the bi-allelic +874(A/T) polymorphisms of IFN-γ. In addition, the distributions of the allelic frequencies were stratified in both the African and mixed race population groups of South Africa. We found striking differences in the allele distribution of IFN-γ ( X 2 = 0.02) among the two ethnic groups. A significant increase in the allele distribution of the IFN-γ AA genotype was found in the African group compared to the mixed population group (OR, 0.5; 95% CI, 0.2-1.0). For IL-10 there were no significant allelic differences between the two South African ethnic groups. Furthermore, when the ethnic groups were combined the IL-10 allelic frequencies in the combined South African data were similar to those observed in an Oriental population from Southern China and in an Italian population. However, the allele frequencies of the IFN-γ genotype among the two South African ethnic groups were different when compared to an Italian Caucasoid group. While crude analysis of these data showed both statistically significantly increased and diminished risks of cervical cancer among high producers of INF-γ and low producers of IL-10 respectively, these associations were no longer significant when the data were adjusted for confounding factors. Conclusion: These findings demonstrate a clear correlation between ethnicity and IFN-γ polymorphism across different population groups. However, these differences in ethnicity and gene polymorphisms in the aforementioned cytokines are suggested not to influence the development of invasive cervical cancer but may represent an important susceptibility biomarker for other diseases and should be explored further.