端粒维持基因多态性与膀胱癌易感性的关系(英文)

Telomere maintenance genes play an important role in maintaining the integrity of the telomere structure that protects chromosome ends,and telomere dysfunction may lead to tumorigenesis.Genetic variation in telomere maintenance genes has been confirmed.Cumulative evidence shows that the difference of telomere length and stability among the individual depends on the genetic variants of telomere maintenance genes.Genetic variants in telomere maintenance genes may affect telomere length and stability,thus the increased cancer risk.This review intends to summarize the association of genetic variants in telomere maintenance genes with bladder cancer risk.     

TGFB1 and TGFBR1 polymorphic variants in relationship to bladder cancer risk and prognosis

The transforming growth factor‐beta (TGF‐β) signalling pathway plays an important role in tumor development and progression. We aimed at analyzing whether 7 different common variants in genes coding for 2 key members of the TGF‐β signalling pathway (TGFB1 and TGFBR1) are associated with bladder cancer risk and prognosis. A total of 1,157 cases with urothelial cell carcinoma of the bladder and 1,157 matched controls where genotyped for 3 single nucleotide polymorphisms (SNPs) in TGFB1 (rs1982073, rs1800472, rs1800471) and an additional 3 SNPs and 1 indel polymorphism in TGFBR1 (rs868, rs928180, rs334358 and rs11466445, respectively). In the case‐control study, we estimated odds ratios and 95% confidence intervals for each individual genetic variant using unconditional logistic regression adjusting for age, gender, study area and smoking status. Survival analysis was performed using the Kaplan‐Meier method and Cox models. The endpoints of interest were tumor relapse, progression and death from bladder cancer. All the SNPs analyzed showed a similar distribution among cases and controls. The distribution of the TGFBR1*6A allele (rs11466445) was also similar among cases and controls, indicating no association with bladder cancer risk. Similarly, none of the haplotypes was significantly associated with bladder cancer risk. Among patients with muscle‐invasive tumors, we found a significant association between TGFBR1‐rs868 and disease‐specific mortality with an allele dosage effect (p‐trend = 0.003). In conclusion, the genetic variants analyzed were not associated with an increased risk of bladder cancer. The association of TGFBR1‐rs868 with outcome should be validated in independent patient series. © 2008 Wiley‐Liss, Inc.     

Genetic variants in RUNX3 and risk of bladder cancer: a haplotype-based analysis

Transforming growth factor-beta (TGF-beta) is a multifunctional growth factor that plays important roles in many biological processes, whereas RUNX3 is a target of TGF-beta-mediated tumor suppressor pathway. In humans, RUNX3 inactivation may lead to the cancer development, including bladder cancer. To determine whether the RUNX3 polymorphisms are associated with risk of bladder cancer, we conducted a case-control study of 368 bladder cancer patients and 368 cancer-free controls to assess the associations between the RUNX3 tagging single-nucleotide polymorphisms (tSNPs) and bladder cancer risk. In the single-locus analysis, we found a significantly increased risk of bladder cancer associated with the SNP7 rs760805 AA genotype (adjusted odds ratio = 1.97, 95% confidence interval = 1.44-2.69), compared with the AT/TT genotype. Haplotype-based association analysis revealed that the increased risk of bladder cancer was significantly associated with two haplotypes TATCCCAAAA (2.37, 1.16-4.83) and AGCTTGAGAG (2.70, 1.08-6.72) that included the rs760805 A allele. Multifactor dimensionality reduction (MDR) analysis identified a significant more than multiplicative interaction between the SNP7 rs760805 AA and smoking and an additive interaction between the SNP3 rs11249206 TT and smoking on bladder cancer risk. The SNP3 rs11249206, SNP5 rs1395621, SNP7 rs760805, SNP8 rs2236852 and the trichotomized cumulative smoking were the five factors best predicted by the MDR models. When the variables were combined and dichotomized and fitted into the MDR model, the subjects carrying the combined risk stratum had a significantly increased risk for bladder cancer (6.37, 4.57-8.87, P = 7.03 x 10(-28)). These results suggested that the genetic variants in RUNX3 may modulate the risk of bladder cancer.     

Genetic variants in epigenetic genes and breast cancer risk

Epigenetic events, resulting changes in gene expression capacity, are important in tumour progression, and variation in genes involved in epigenetic mechanisms might therefore be important in cancer susceptibility. To evaluate this hypothesis, we examined common variants in 12 genes coding for DNA methyltransferases (DNMT), histone acetyltransferases, histone deacetyltransferases, histone methyltrasferases and methyl-CpG binding domain proteins, for association with breast cancer in a large case-control study (N cases = 4474 and N controls = 4580). We identified 63 single nucleotide polymorphisms (SNPs) that efficiently tag all the known common variants in these genes, and are also expected to tag any unknown SNP in each gene. We found some evidence for association for six SNPs: DNMT3b-c31721t [P (2 df) = 0.007], PRDM2-c99243 t [P (2 df) = 0.03] and t105413c [P-recessive = 0.05], EHMT1-g-9441a [P (2df) = 0.05] and g41451t (P-trend = 0.04), and EHMT2-S237S [P (2df) = 0.04]. The most significant result was for DNMT3b-c31721t (P-trend = 0.124 after adjusting for multiple testing). However, there were three other results with P < 0.05. The permutation-based probability of this occurring by chance was 0.335. These significant SNPs were genotyped in 75 human cancer cell lines from different tumour types to assess if there was an association between them and six epigenetic measures. No statistically significant association was found. However, a trend was observed: homozygotes for the rare alleles of the EHMT1, EHMT2 and PRDM2 had a mean value for both trimethylation of K9 and K27 of histone H3 remarkably different to the homozygotes for the common alleles. Thus, these preliminary observations suggest the possible existence of a functional consequence of harbouring these genetic variants in histone methyltransferases, and warrant the design of larger epidemiological and biochemical studies to establish the true meaning of these findings.     

中国汉族人群前列腺癌易感性与TLR4基因单核苷酸多态性的研究

目的 探讨Asp299Gly(rs4986790)、Thr399Ile(rs4986791)、rs11536889单核苷酸多态性(SNP)与前列腺癌(PCa)易感性和严重程度的关系.方法 采用病例对照研究方法,选取组织学证据确诊的PCa患者96例为PCa组,良性前列腺增生(BPH)患者87例为BPH组,健康者92例为健康对照组.记录研究对象的临床资料并计算Gleason评分,PCR-RFLP法分析各组的基因型.结果 PCa组、BPH组及健康对照组的年龄、前列腺癌家族史所占比例、前列腺特异抗原(PSA)水平比较,差异均有统计学意义(P=0.000);PCa组、BPH组及健康对照组的Asp299Gly和Thr399Ile基因型频率分布比较,差异无统计学意义(P﹥0.05),但3组间rs11536889基因型频率分布比较,差异有统计学意义[PCa组/(BPH组+健康对照组),CC/GC vs GG,OR=2.152,95%CI:1.280~3.618,P﹤0.05];Gleason评分≥7分组GC+CC分布比例高于Gleason评分﹤7分组(OR=2.378,95%CI:1.042~4.427,P﹤0.05).结论 TLR4基因rs11536889 SNP可能与PCa发病和病情严重程度相关.     

Genetic variants of p21 and p27 and hepatocellular cancer risk in a Chinese Han population: A case‐control study

The p21 (Cip1/CDKN1A) and p27 (Kip1/CDKN1B) are members of the Cip/Kip family of cyclin‐dependent kinase inhibitors, which can arrest cell proliferation and serve as tumour suppressors. We hypothesized that genetic variants in p21 and p27 may modify individual susceptibility to hepatocellular carcinoma (HCC). To test this hypothesis, we evaluated the associations of the polymorphisms of Ser31Arg and C+20T in p21 and C‐79T and Gly109Val in p27, as well as their combinations, with HCC risk in a case‐control study of 476 HCC cases and 526 cancer‐free controls in a Chinese population. The matrix‐assisted laser desorption ionisation time‐of‐flight (MALDI‐TOF) mass spectrometry method was performed to detect these polymorphisms. We found that the variant genotypes of p21 Ser31Arg and p27 C‐79T were individually associated with a significantly increased risk of HCC, but no associations were observed for other variant genotypes. Moreover, the combined variant genotypes of the four loci were associated with a significantly increased HCC risk (adjusted OR = 2.24, 95% CI = 1.72, 2.91 among subjects carrying 3 or more variant alleles), especially among HbsAg‐positive individuals (adjusted OR = 3.09, 95% CI = 1.86, 5.14). Furthermore, the combined variant genotypes of the four loci (carrying three or more variant alleles) increased a 1.93‐fold (95% CI = 1.20, 3.09) and 1.76‐fold (95% CI = 1.17, 2.64) risk of HCC among smokers and nonsmokers. The variant genotypes of the two genes in this study have negative correlation with the clinicopathologicals observed. These results suggest that p21 polymorphisms individually or in combination with p27 polymorphisms increases risk of HCC, particularly among HbsAg‐positive individuals.     

Genetic variants of adiponectin and risk of colorectal cancer

Circulating adiponectin has been associated with lower risk of colorectal cancer (CRC). Genome‐wide association studies have identified several single‐nucleotide polymorphisms (SNPs) associated with adiponectin levels. However, it is unclear whether these SNPs are associated with CRC risk. In addition, previous data on SNPs in the adiponectin pathway and their associations with CRC are inconsistent. Therefore, we examined 19 SNPs in genes related to adiponectin or its receptors and their associations with CRC using logistic regression among 7,020 cases and 7,631 controls drawn from ten studies included in the Genetics and Epidemiology of Colorectal Cancer Consortium. Using data from a subset of two large cohort studies, we also assessed the contribution of individual SNPs and an adiponectin genetic score to plasma adiponectin after accounting for lifestyle factors among 2,217 women and 619 men. We did not find any statistically significant association between the 19 adiponectin‐associated SNPs and CRC risk (multivariable‐adjusted odds ratios ranged from 0.89 to 1.05, all p > 0.05). Each SNP explained less than 2.50% of the variance of plasma adiponectin, and the genetic score collectively accounted for 2.95 and 1.42% of the variability of adiponectin in women and men, respectively, after adjustment for age, body mass index, physical activity, smoking, alcohol consumption, regular use of aspirin or nonsteroidal anti‐inflammatory drug and postmenopausal hormone use. In conclusion, our findings do not support an association between known adiponectin‐related common SNPs and CRC incidence. However, known common SNPs account for only a limited proportion of the interindividual variance in circulating adiponectin. Further work is warranted to investigate the relationship between adiponectin and CRC while accounting for other components in the pathway.     

Association between glutathione S-transferase M1 null variant and risk of bladder cancer in Chinese Han population

Glutathione S-transferase M1 (GSTM1) is one of the most important families of phase II isoenzymes known to detoxify a variety of electrophilic compounds and carcinogens. The GSTM1 null variant is associated with decreased enzyme activity, and it has been assumed to be associated with bladder cancer. The association between the GSTM1 null variant and bladder cancer in the Chinese Han population was unclear owing to the obvious inconsistency from published studies. To quantify the association between the GSTM1 null variant and bladder cancer in the Chinese Han population, we carried out the meta-analysis. We estimated the pooled odds ratio (OR) with its 95 % confidence interval (95 % CI) to assess the association. Eight studies with a total of 3,887 individuals were finally included into the meta-analysis. Overall, there was an obvious association between the GSTM1 null variant and risk of bladder cancer in the Chinese Han population (OR?=?1.61, 95 % CI 1.41–1.84, P?<?0.001). There was no heterogeneity across those eight studies (I ²?=?0 %). The cumulative meta-analyses showed a trend of more obvious association between the GSTM1 null variant and risk of bladder cancer in the Chinese Han population as data accumulated by year. There was no obvious evidence of publication bias in the meta-analysis. In conclusion, the GSTM1 null variant is significantly associated with risk of bladder cancer in the Chinese Han population.     

Evaluation of genetic variants in microRNA-related genes and risk of bladder cancer

MicroRNAs (miRNA) are small noncoding RNA molecules involved in a diversity of cellular functions. Although it has been reported that global suppression of the miRNA biogenesis pathway leads to enhanced tumorigenesis, the effect of common genetic variants of miRNA-related genes on cancer predisposition is unclear. To better understand this effect, we genotyped 41 single-nucleotide polymorphisms (SNP) from 24 miRNA-related genes in a case-control study conducted in 746 Caucasian patients with bladder cancer and 746 matched controls. The homozygous variant genotype of a nonsynonymous SNP in the GEMIN3 gene (rs197414) was associated with a significantly increased bladder cancer risk [odds ratios (OR), 2.40; 95% confidence interval (95% CI), 1.04-5.56]. Several additional miRNA-related SNPs were also identified that showed a borderline significant association with bladder cancer risk. Haplotype analysis indicated that a common haplotype of the GEMIN4 gene was associated with a significantly increased bladder cancer risk with an OR of 1.25 (95% CI, 1.01-1.54). To assess the aggregate effects of the promising SNPs, we performed a combined unfavorable genotype analysis that included all SNPs showing at least a borderline statistical significance. We found that, compared with the low-risk reference group with less than two unfavorable genotypes, the medium-risk group with two unfavorable genotypes exhibited a 1.29-fold (0.92-1.81) increased risk whereas the high-risk group with more than two unfavorable genotypes exhibited a 1.92-fold (1.36-2.71) increased risk (P(trend) < 0.0001). Overall, this is the first epidemiologic study showing that miRNA-related genetic variants may affect bladder cancer risk individually and jointly.     

Alternative splicing related genetic variants contribute to bladder cancer risk

Emerging evidence has shown that aberrant alternative splicing (AS) events are involved in the carcinogenesis. The association between genetic variants in AS and bladder cancer susceptibility remains to be fully elucidated. We searched for single nucleotide polymorphisms (SNPs) which are located in splicing quantitative trait loci (sQTLs) in bladder cancer through CancerSplicingQTL database and the 1000 Genomes Project. A case-control study including 580 cases and 1,101 controls was conducted to assess the association between the functional genetic variants and bladder cancer risk. Next, we used GTEx, TCGA, and GEO databases conducting sQTL analysis and gene expression differences analysis to evaluate the potential biological function of the candidate SNPs and related genes. We found that SNP rs4383 C>G was remarkably related with the reduced risk of bladder cancer (odds ratio = 0.68, 95% confidence interval = 0.59-0.79, P = 3.91 × 10⁻⁷). Similar results were obtained in codominant, dominant and recessive model. Stratified analyses revealed that the effect of SNP rs4383 C>G on bladder cancer was more significant in the older subjects (age > 65), female and nonsmokers. sQTL analysis showed that SNP rs4383 was associated with the AS events of its downstream gene MAFF with a splicing event of alternative 5′ splice site. The messenger RNA expression of MAFF in bladder tumor tissues was lowered compared with normal tissues. Patients with high expression of MAFF had higher survival rates. These findings indicated that SNP rs4383 related with the AS events of MAFF was associated with bladder cancer risk and could represent a possible biomarker for bladder cancer susceptibility.     

Genetic variants in cell cycle control pathway confer susceptibility to bladder cancer

BACKGROUND

Cell cycle checkpoint regulation is crucial for the prevention of carcinogenesis in mammalian cells.

METHODS

To test the hypothesis that common sequence variants in the cell cycle control pathway may affect bladder cancer susceptibility, the effects of a panel of 10 potential functional single nucleotide polymorphisms (SNPs) from 7 cell cycle control genes, P53, P21, P27, CDK4, CDK6, CCND1, and STK15, were evaluated on bladder cancer risk in a case‐control study of 696 bladder cancer cases and 629 healthy controls.

RESULTS

Overall, on individual SNP analysis only individuals with the p53 intron 3 16‐bp duplication polymorphism variant allele had a significantly reduced bladder cancer risk (odds ratio [OR] = 0.74, 95% confidence interval [CI], 0.56–0.96). This effect was more evident in former smokers and younger subjects. We then applied the Classification and Regression Tree (CART) statistical approach to explore the high‐order gene‐gene and gene‐smoking interactions. In the CART analysis, smoking status was identified as the most influential factor for bladder cancer susceptibility. The final decision tree by CART contained 6 terminal nodes. Compared with the second‐lowest risk group the ORs for terminal nodes 1 and 3 to 6 ranged from 0.46 to 6.30.

CONCLUSIONS

These results suggest that cell cycle genetic polymorphisms may affect bladder cancer predisposition through modulation of host genome stability and confirm the importance of studying gene‐gene and gene‐environment interactions in bladder cancer risk assessment. Cancer 2008. © 2008 American Cancer Society.     

Genetic variants of NBS1 predict clinical outcome of platinum-based chemotherapy in advanced non-small cell lung cancer in Chinese

Objective: NBS1 plays a key role in the repair of DNA double-strand break (DSB). We conducted this study to investigate the effect of two critical polymorphisms (rs1805794 and rs13312840) in NBS1 on treatment response and prognosis of advanced non-small cell lung cancer (NSCLC) patients with platinum-based chemotherapy. Methods: Using TaqMan methods, we genotyped the two polymorphisms in 147 NSCLC patients. Odds ratios (ORs) and their 95% confidential intervals (CIs) were calculated as a measure of difference in the response rate of platinum-based chemotherapy using logistic regression analysis. The Kaplan-Meier and log-rank tests were used to assess the differences in progression-free survival (PFS) and overall survival (OS). Cox proportional hazards model was applied to assess the hazard ratios (HRs) for PFS and OS. Results: Neither of the two polymorphisms was significantly associated with treatment response of platinum-based chemotherapy. However, patients carrying the rs1805794 CC variant genotype had a significantly improved PFS compared to those with GG genotype (16.0 vs. 8.0 months, P = 0.040). Multivariable cox regression analysis further showed that rs1805974 was a significantly favorable prognostic factor for PFS [CC/CG vs. GG: Adjusted HR = 0.62, 95% CI: 0.39-0.99; CC vs. CG/GG: Adjusted HR = 0.56, 95% CI: 0.32-0.97). Similarly, rs13312840 with a small sample size also showed a significant association with PFS (CC vs. CT/TT: Adjusted HR = 25.62, 95% CI: 1.53-428.39). Conclusions: Our findings suggest that NBS1 polymorphisms may be genetic biomarkers for NSCLC prognosis especially PFS with platinum-based chemotherapy in the Chinese population.     

Genetic variants of myeloperoxidase and catechol-O-methyltransferase and breast cancer risk.

This nested case-control study evaluated the role of polymorphisms in the myeloperoxidase (MPO) and catechol-O-methyltransferase (COMT) genes that modulate oxidative stress in breast cancer risk in a Chinese population. Our results demonstrate that the MPO A/A genotype was associated with a reduced risk of breast cancer (odds ratio (OR) 0.64; 95% confidence interval (CI) 0.11-3.76), whereas there was no overall association of COMT genotype with breast cancer. Of note, an elevated breast cancer risk associated with the increasing numbers of high-risk genotypes of MPO and COMT genes was observed in women with a longer duration between menarche and first full-term pregnancy.     

Fluid intake,genetic variants of UDP-glucuronosyltransferases,and bladder cancer risk

Background:

Results of studies of fluid consumption and its association with bladder cancer have been inconsistent. Few studies have considered modification effects from genetic variants that may interact with the type of consumed fluids. UDP-glucuronosyltransferases (UGTs), which are membrane-bound conjugating enzymes, catalyse the transformation of hydrophobic substrates to more water-soluble glucuronides to facilitate renal or biliary excretion. Whether genetic variants in UGTs could modulate the association between fluid intake and bladder cancer has not been studied.

Methods:

We conducted a case–control study with 1007 patients with histopathologically confirmed bladder cancer and 1299 healthy matched controls. Fluid intake and epidemiologic data were collected via in-person interview. Multivariate unconditional logistic regression was used to estimate odds ratios (ORs) and the 95% confidence intervals (95% CI).

Results:

After adjustment for potential confounders, high quantity of total fluid intake (⩾2789 vs <1696 ml per day) conferred a 41% increased risk of bladder cancer (OR=1.41; 95% CI=1.10–1.81). Specific fluids such as regular soft drinks and decaffeinated coffee were also associated with increased risks, whereas tea, wine, and liquor were associated with decreased risks. Among 83 single-nucleotide polymorphisms in the UGT gene family, 18 were significantly associated with bladder cancer risk. The most significant one was rs7571337, with the variant genotype conferring a 29% reduction in risk (OR=0.71; 95% CI=0.56–0.90).

Conclusions:

Total and specific fluid intakes are associated with bladder cancer risk in the study population and that genetic variants of UGT genes could modulate the effects. These results facilitate identification of high-risk individuals and have important implications in bladder cancer prevention.     

Genetic variants in fas signaling pathway genes and risk of gastric cancer

Populations in north central China are at high risk for gastric cancers (GC), and altered FAS‐mediated cell signaling and/or apoptosis may contribute to this risk. We examined the association of 554 single nucleotide polymorphisms (SNPs) in 53 Fas signaling‐related genes using a pathway‐based approach in 1758 GC cases (1126 gastric cardia adenocarcinomas (GCA) and 632 gastric noncardia adenocarcinomas (GNCA)), and 2111 controls from a genome‐wide association study (GWAS) of GC in ethnic Chinese. SNP associations with risk of overall GC, GCA and GNCA were evaluated using unconditional logistic regressions controlling for age, sex and study. Gene‐ and pathway‐based associations were tested using the adaptive rank‐truncated product (ARTP) method. Statistical significance was evaluated empirically by permutation. Significant pathway‐based associations were observed for Fas signaling with risk of overall GC (p = 5.5E‐04) and GCA (p = 6.3E‐03), but not GNCA (p= 8.1E‐02). Among examined genes in the Fas signaling pathway, MAP2K4, FAF1, MAPK8, CASP10, CASP8, CFLAR, MAP2K1, CAP8AP2, PAK2 and IKBKB were associated with risk of GC (nominal p < 0.05), and FAF1 and MAPK8 were significantly associated with risk of both GCA and GNCA (nominal p< 0.05). Our examination of genetic variation in the Fas signaling pathway is consistent with an association of altered Fas signaling and/or apoptosis with risk of GC. As one of the first attempts to investigate a pathway‐level association, our results suggest that these genes and the Fas signaling pathway warrant further evaluation in relation to GC risk in other populations.