No association between HER-2 gene polymorphism at codon 655 and a risk of bladder cancer

The amplification and overexpression of the human epidermal growth factor receptor 2 gene HER-2 (also known as c-erb-B2 or neu) have been shown to be associated with bladder cancer and its progression. Recent studies indicated an association between the Ile to Val polymorphism at codon 655 of HER-2 and susceptibility to breast cancer. To investigate the correlation between the Ile/Val polymorphism and the susceptibility and progression of bladder cancer, we analyzed the polymorphism in 232 patients with transitional cell carcinoma of the bladder and 408 normal controls. The frequencies of the Ile/Ile, Ile/Val and Val/Val genotype were 75.9%, 21.6% and 2.6%, respectively, in patients with bladder cancer and 75.7%, 23.0% and 1.2%, respectively, in controls. Statistical analyses of the genotype prevalence showed no significant difference between bladder cancer patients and normal controls (p = 0.419). Moreover, no significant differences in the genotype prevalence were observed when the patients were stratified according to the tumor grade, stage and smoking habits. When the Ile/Ile genotype was compared to the Ile/Val and Val/Val genotypes, a significant difference was found only between the patients with tumor stage Ta and those with T1-4 (age, gender and smoking habits-adjusted odds ratio = 2.13, 95% confidence interval = 1.09-4.15, p = 0.027). When the Ile/Ile + Ile/Val genotypes compared to the Val/Val genotype, no significant findings were observed. These results suggested that the HER-2 polymorphism at codon 655 is unlikely to be associated with the onset of bladder cancer. Furthermore, the findings suggest no association between this polymorphism and the disease progression in bladder cancer, although the possibility remains that the Ile/Ile genotype may be related to an increased risk of disease progression.     

Polymorphisms in ERCC2, MSH2, and OGG1 DNA repair genes and gallbladder cancer risk in a population of Northern India

BACKGROUND:

Genetic variants of DNA repair enzymes may lead to genetic instability and contribute to gallbladder (GB) carcinogenesis.

METHODS:

A case‐control study (230 GB carcinogenesis patients and 230 controls) was undertaken to evaluate whether genetic variations in 3 DNA repair genes ERCC2 (Asp312Asn [rs1799793] and Lys751Gln [rs13181]), MSH2 (?118T>C [rs2303425] and IVS1 + 9G>C [rs2303426]), and OGG1 (Ser326Cys [rs1052133] and 748‐15C>G [rs2072668]) are associated with GB carcinogenesis risk in a North Indian population.

RESULTS:

The authors found that the ERCC2 Asp312Asn AA, MSH2 IVS1 + 9G>C CC, OGG1 Ser326Cys GG and CG + GG, and OGG1 748‐15C>G GG and CG + GG genotypes were significantly associated with an increased risk of GB carcinogenesis (odds ratio [OR], 2.1, 1.8, 2.5, 1.8, 2.0, and 1.6, respectively). In contrast, ERCC2 Lys751Gln, and MSH2 ?118T>C markers showed no significant associations with GB carcinogenesis risk, although because of the small sample size their effects cannot be ruled out. Female GB carcinogenesis patients with the OGG1 748‐15C>G GG, OGG1 Ser326Cys GG, and ERCC2 Asp312Asn genotypes had a greater risk for developing the disease (OR, 3.6, 7.7, and 2.7, respectively). There was a significant interaction between MSH2 IVS1 + 9G>C and OGG1 748‐15C>G polymorphisms (P = .001). Furthermore, individuals with >6 variant alleles of the studied polymorphisms were at 4‐fold increased risk for developing GB carcinogenesis. Classification and Regression Tree analysis revealed potential higher‐order gene‐gene interactions and categorized a few higher‐risk subgroups for GB carcinogenesis.

CONCLUSIONS:

These results suggest that genetic variants in the DNA repair pathways may be involved in GB carcinogenesis etiology. Cancer 2010. © 2010 American Cancer Society.     

MAP3K1及LSP1基因单核苷酸多态与中国北方汉族绝经前妇女乳腺癌风险相关性

目的:探讨MAP3K1及LSP1基因单核苷酸多态与中国北方汉族绝经前妇女乳腺癌风险的关系。方法:采用多重单碱基延伸单核苷酸多态性分型技术(Snapshot)分析方法,检测280例绝经前乳腺癌患者和287例绝经前正常对照者MAP3K1基因rs889312和LSP1基因rs3817198多态性位点基因型,并比较不同基因型与乳腺癌风险的关系。结果:MAP3K1基因rs889312和LSP1基因rs3817198多态性位点基因型频率在乳腺癌和对照样本之间未存在显著差异(P=0.937、P=0.323)。Logistic回归分析结果显示,对于MAP3K1的rs889312位点,与AA携带者相比,AC携带者、CC携带者和AC+CC基因型携带者与乳腺癌的患病危险无关(OR=0.814,95%CI=0.537-1.236,P=0.335;OR=0.999,95%CI=0.627-1.594,P=0.998;OR=0.876,95%CI=0.591-1.298,P=0.509);对于LSP1的rs3817198位点,与TT携带者相比,CT携带者、CC携带者和CT+CC基因型携带者与乳腺癌的患病危险无关(OR=0.832,95%CI=0.565-1.223,P=0.349;OR=0.651,95%CI=0.108-3.936,P=0.640;OR=0.839,95%CI=0.573-1.229,P=0.369)。结论:上述两个基因MAP3K1和LSP1位点多态性与中国北方汉族绝经前妇女乳腺癌易感性之间无明显相关性。     

TOX3基因单核苷酸多态与中国北方汉族绝经前妇女乳腺癌风险关联的研究

目的:探讨TOX3基因单核苷酸多态与中国北方汉族绝经前妇女乳腺癌风险的关系。方法:采用多重单碱基延伸单核苷酸多态性分型技术(Snapshot)分析方法,检测280例绝经前的乳腺癌患者和287例绝经前的正常对照者TOX3基因rs3803662和rs12443621多态性位点基因型,并比较不同基因型与乳腺癌风险的关系。结果:TOX3基因rs3803662和rs12443621多态性位点基因型频率,在乳腺癌病例组和对照组之间差异无统计学意义,P值分别为0.718和0.340。Logistic回归分析结果显示,对于rs3803662位点,与GG基因型相比,GA、AA和GA+AA基因型与乳腺癌的危险性无关(OR=0.846,95%CI:0.489～1.463,P=0.549;OR=0.802,95%CI:0.470～1.368,P=0.418;OR=0.821,95%CI:0.492～1.368,P=0.449);对于rs12443621位点,与GG基因型相比,GA、AA和GA+AA基因型与乳腺癌的危险性无关(OR=0.755,95%CI:0.518～1.099,P=0.755;OR=0.850,95%CI:0.528～1.368,P=0.504;OR=0.781,95%CI:0.548～1.112,P=0.170)。结论:在目前样本条件下,TOX3基因rs3803662和rs12443621位点多态性与中国北方汉族绝经前妇女乳腺癌易感性之间无明显关联。     

FGFR1基因单核苷酸多态性与中国北方汉族女性乳腺癌发病风险及临床病理特征的关系

目的:探究成纤维生长因子受体1（fibroblast growth factor receptor-1,FGFR1)基因单核苷酸多态性与中国北方汉族女性乳腺癌发病风险和临床病理特征的相关性。方法:采用多重单碱基延伸单核苷酸多态性分型技术检测747例乳腺癌患者和716例健康女性人群FGFR1基因rs13317和rs3213849多态位点基因型,并比较不同基因型与乳腺癌发病风险和临床病理特征的关系。结果:FGFR1基因rs13317和rs3213849多态位点基因型频率在乳腺癌组和对照组中的分布无统计学差异(P＞0.05)。与TT基因型携带者相比,rs13317位点的CT基因型、CC基因型和CT+CC基因型携带者与乳腺癌发病风险无关(P=0.464、P=0.136、P=0.103)。与GG基因型携带者相比,rs3213849位点的GA基因型、AA基因型和GA+AA基因型携带者与乳腺癌发病风险无关(P=0.642、P=0.222、P=0.416)。临床病理分析结果显示,rs13317位点多态性与乳腺癌患者的临床分期、肿瘤大小、组织学分级、淋巴结转移、ER、PR、HER2、Ki67及p53无关(P＞0.05)。在共显性模型下,rs3213849位点在Ki67分布上可能存在差异(P=0.055);在显性模型下,rs3213849位点与Ki67表达情况具有相关性(P=0.023),与其他临床病理因素之间均不相关(P＞0.05)。结论:在目前的样本条件下,FGFR1基因rs3213849位点与Ki67表达可能相关,而rs13317和rs3213849多态性与中国北方汉族女性乳腺癌易感性及其他临床病理特征之间无明显相关性。     

CYP1B1 and hormone-induced cancer

Cancers in hormone-responsive tissues (e.g., breast, ovary, endometrium, prostate) occur at high incidence rates worldwide. However, their genetic basis remains poorly understood. Studies to date suggest that endogenous/exogenous oestrogen and environmental carcinogens may play a role in development and/or progression of hormone-induced cancers via oxidative oestrogen metabolism. Cytochrome P450 1B1 is a key enzyme in its oestrogen metabolism pathway, giving rise to hydroxylation and conjugation. Although CYP1B1 is expressed in many cancers, particularly high levels of expression are observed in oestrogen-mediated disease. CYP1B1 is more readily found in tumour tissue compared to normal. Given the role of CYP1B1 in pro-carcinogen and oestrogen metabolism, polymorphisms in CYP1B1 could result in modifications in its enzyme activity and subsequently lead to hormone-mediated carcinogenesis. CYP1B1 may also be involved in progression of the disease by altering the tissue response to hormones and clinical response to chemotherapy. The exact mechanism behind these events is complex and unclear. Only a few functional single nucleotide polymorphisms of CYP1B1 are known to result in amino acid substitutions and have been extensively investigated. Studies examining the contribution of different CYP1B1 alleles to hormone-mediated cancer risks are inconsistent. The main focus of this review is to appraise the available studies linking the pathogenesis of the hormone-induced cancers to various CYP1B1 polymorphisms. Additionally, we explore the role of a neuronal protein, γ-synuclein, in CYP1B1-mediated pathogenesis.     

DNA repair systems in malignant mesothelioma

Malignant mesothelioma (MM) is an aggressive tumor of serosal surfaces with increasing incidence and poor prognosis. Asbestos exposure is the main cause of MM and asbestos-induced DNA damage is critical for MM pathogenesis. The present review summarizes the implications of DNA repair systems in MM development, focusing on gene expression alterations and single nucleotide polymorphisms of genes encoding for DNA repair enzymes. The involvement of DNA repair systems in MM improves understanding of MM pathogenesis and provides novel therapeutical targets.