DNA修复基因XRCC1的399位点多态性同肺癌易感性关系的Meta分析

目的综合评价DNA修复基因XRCC1(X-raycross-complementinggroup1)的399位点多态性同肺癌易感性的关系。方法检索中国生物医学数据库和Medline,获得有关XRCC1基因399位点多态性同肺癌易感性关系的研究结果,并进行Meta分析。所有文献均采用病例对照研究,以非条件Logistic回归校正年龄、性别和吸烟状况等混杂因素后的OR值为效应指标,对文献进行评价筛选、异质性检验。利用Meta分析软件RevMan4·2对各研究原始结果进行统计处理,并计算合并OR值及其95%可信区间。结果本次Meta分析共纳入15项研究,累计病例6818例,对照7610例。Arg/Gln和Gln/Gln等位基因同Arg/Arg比较,OR值分别为0·99(95%CI0·91~1·06)和1·04(95%CI0·92~1·17),Z值分别为-0·37和0·67,对应的P值分别为0·71和0·50。结论尚无足够证据证明DNA修复基因XRCC1的399位点多态性同肺癌易感性有关。     

A population-based case-control study of the Arg399Gln polymorphism in DNA repair gene XRCC1 and risk of breast cancer.

XRCC1 (X-ray repair cross-complementing group 1) is a base excision repair protein that plays a central role in the repair of DNA base damage and strand breaks. A common polymorphism (Arg-->Gln) at codon 399 of the XRCC1 gene has been previously linked to functional changes of the gene product and risk of cancers. We evaluated the association between XRCC1 Arg399Gln polymorphism and breast cancer risk in the population-based Shanghai Breast Cancer Study involving 1088 cancer patients and 1182 community controls. Genomic DNA from peripheral blood was used in genotyping assays, and exposure information and anthropometrics were collected through in-person interview. Plasma estrogen and sex hormone-binding globulin (SHBG) levels were measured for 190 postmenopausal breast cancer patients who had donated a pretreatment blood sample and 407 postmenopausal controls. Conditional logistic regression model was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs) adjusting potential confounders. Approximately 27% of controls carried the variant allele (Gln), and cases and controls had a similar distribution for both allele type and genotype of this polymorphism. We found that 7.8% of cases and 6.3% of controls were homozygous for the variant allele, resulting in an OR of 1.20 (95% CI, 0.85-1.69). The OR was slightly higher among younger women [<45 years of age (OR, 1.39; 95% CI, 0.82-2.36)] than older women [> or = 45 years of age (OR, 1.07; 95% CI, 0.68-1.67)], but neither OR was statistically significant. No modifying effect of major breast cancer risk factors, including years of menstruation, body mass index, waist:hip ratio, and blood estrogen levels, was noted. Homozygosity for the variant Gln allele was associated with an elevated risk of postmenopausal breast cancer among subjects with a higher blood level of SHBG (OR, 3.27; 95% CI, 1.16-9.20) and a reduced risk among those with a lower level of SHBG (OR, 0.60; 95% CI, 0.18-1.97). The overall results of the study suggest that Arg399Gln polymorphism of the XRCC1 gene alone may not play a substantial role in the risk of breast cancer among Chinese women.     

XRCC1基因Arg399Gln多态与胃癌临床病理因素的关系

背景与目的：DNA修复基因XRCC1参与DNA损伤的碱基切除修复途径（BER），其Arg399Gln多态可以改变蛋白产物的DNA修复效能．本研究探讨XRCC1基因Arg399Gln多态与胃癌临床病理因素的关联性。方法：采用聚合酶链反应PCR-变性高效液相色谱分析（denaturing high performance liquid chromatography，DHPLC）方法对102例胃癌患者进行XRCC1基因Arg399Gln多态的基因型分析，比较基因型分布与胃癌组织临床病理特征之间的关系。结果：XRCC1基因Arg399Gln多态的Arg／Arg（GG），Arg／Gin（G→A）及Gin／Gin（AA）基因型在病例组中的分布频率分别为46（45．1％），48（47．1％），8（7．8％）；含至少一个399Gln的基因型患胃癌的年龄明显要小（P=0．07）；Arg399Gln多态性与胃癌的病理类型、肿瘤部位、组织分级、浸润深度及淋巴结转移、临床分期间没有显著关系（P〉0．05）。结论：XRCC1基因399Gln等位基因可能是胃癌早年发病的危险因素之一；但不是判断胃癌侵袭相关的生物学行为的预测指标。这些结果还需要大样本量的胃癌分子流行病学研究加以验证。     

Assessment of the association between XRCC1 Arg399Gln polymorphism and glioma susceptibility

The Arg399Gln polymorphism, located in the region of the BRCT-I interaction domain of XRCC1, has been extensively explored in its function and association with glioma risk. However, these studies generated contradictory instead of conclusive results. A meta-analysis was performed to derive a more precise evaluation of the relationship between XRCC1 Arg399Gln polymorphism and glioma risk. We searched the PubMed, EMBASE, and Web of Science and extracted 12 eligible studies with 4,062 glioma cases and 5,302 glioma-free controls for this meta-analysis. The pooled odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated to assess the strength of the association. In the overall analysis, we found that the XRCC1 Arg399Gln polymorphism was statistically associated with the risk of glioma (OR_{GG vs. AG + AA}?=?0.90, 95 % CI?=?0.84–0.97, P _{heterogeneity}?=?0.020; OR_{allele G vs. allele A}?=?0.96, 95 % CI?=?0.91–1.00, P _{heterogeneity}?=?0.110). We also observed significant association between this polymorphism and glioma risk in Asian populations. The results of the meta-analysis suggest a potential decreased susceptibility to glioma in association with the XRCC1 Arg399Gln polymorphism, especially in Asians. Yet, it is necessary to conduct future prospective explorations to gain a better insight into the impact of XRCC1 Arg399Gln polymorphism on glioma risk.     

XRCC1 Arg399Gln gene polymorphism and breast cancer risk: a meta-analysis based on case-control studies

Background: The Arg399Gln polymorphism in the XRCC1 DNA repair gene is likely to be involved with the development of breast cancer (BC). However, there have been inconsistent reports of association. The objective of this study was to systematically evaluate the published papers. Methods: We performed a meta-analysis of 44 published case-control studies fitting our eligibility criteria. These studies involved XRCC1 Arg399Gln polymorphisms in 20,841 BC cases and 22,688 controls in dominant (GlnGln+ArgGln vs. ArgArg), recessive (GlnGln vs. ArgGln+ArgArg), and co-dominant (GlnGln vs. ArgArg) inheritance models. Analyses of Asian, African and Caucasian ethnic subgroups was also conducted. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. Results: Our overall analyses indicated Arg399Gln to be associated with a trend of increased BC risk when using recessive (OR=1.15, 95%CI: 1.05–1.27), and co-dominant models (OR=1.15, 95%CI: 1.04-1.27) to analyze the data. In ethnic subgroups, Arg399Gln significantly increased BC risk in Asians (OR=1.54, 95%CI: 1.18–2.01) when using recessive model analysis, in Africans (OR=1.30, 95%CI: 1.07–1.60) when using dominant model analysis, and in Asians (OR=1.50, 95%CI: 1.15–1.97) and Africans (OR=1.80, 95%CI: 1.08-3.02) when using the co-dominant model analysis. Conclusions: From our meta-analysis of data from 44 publications, we conclude that XRCC1 Arg399Gln allele is a risk factor for the development breast cancer, especially among Asian and African populations.     

Assessment of the association between XRCC1 Arg399Gln polymorphism and lung cancer in Chinese

X-ray repair cross-complementing group 1 (XRCC1) is one of the major DNA repair proteins involved in the base excision repair and plays an important role in the maintenance of genomic integrity. Polymorphisms in XRCC1 may alter the function and repair capacity of XRCC1 protein which further results in the genetic instability and lung carcinogenesis. Previous studies investigating the relationship between XRCC1 Arg399Gln polymorphism and lung cancer risk in Chinese yielded contradictory results. A meta-analysis was performed to clarify the effect of XRCC1 Arg399Gln polymorphism on lung cancer. The association was assessed by calculating the pooled odds ratio (OR) with 95 % confidence intervals (95 %CI). Nineteen studies with a total of 12,835 participants were included into this meta-analysis. Overall, there was an obvious association between XRCC1 Arg399Gln polymorphism and increased risk of lung cancer under three genetic models (Gln vs. Arg: OR?=?1.13, 95 %CI 1.01–1.25, P?=?0.029; GlnGln vs. ArArg: OR?=?1.41, 95 %CI 1.07–1.84, P?=?0.013; GlnGln vs. ArArg/ArgGln: OR?=?1.37, 95 %CI 1.07–1.76, P?=?0.013). Meta-analysis of 18 studies with high quality also found that there was an obvious association between XRCC1 Arg399Gln polymorphism and increased risk of lung cancer under three genetic models. There was no obvious risk of bias in the meta-analysis. Data from the current meta-analysis support the obvious association between XRCC1 Arg399Gln polymorphism and increased risk of lung cancer in Chinese.     

An updated meta-analysis between the association of XRCC1 Arg399Gln polymorphism and hepatocellular carcinoma risk

Background: Various studies have evaluated the relationship between X-ray repair cross-complementinggroup 1 (XRCC1) Arg399Gln polymorphism and hepatocellular carcinoma (HCC) risk, but the conclusionshave been inconsistent and underpowered. The purpose of this updated meta-analysis was to examine whetherXRCC1 Arg399Gln polymorphism confers susceptibility to HCC. Methods: Eligible studies extracted fromPubMed, Embase, Cochrane Library, VIP (chinese) and CNKI (chinese) up to November 2013 were included inthe study. Pooled odds ratio (OR) together with their 95% confidence interval (CI) were estimated to evaluateXRCC1 Arg399Gln polymorphism and HCC risk. Results: Finally, 21 studies with 4,170 cases and 5,030controls were involved in our meta-analysis. The results demonstrated that there was significant associationbetween Arg399Gln polymorphism and HCC risk under two contrast models in overall populations (AG vs GG:OR=1.265, 95%CI=1.036-1.545, p=0.021; AA+AG vs GG: OR=1.240, 95%CI=1.021-1.506, p=0.030). In subgroupanalyses, significant association was found in Asians (A vs G: OR=1.175, 95%CI=1.013-1.362, p=0.033; AG vsGG: OR=1.317, 95%CI=1.070-1.622, p=0.009; AA+AG vs GG: OR=1.289, 95%CI=1.055-1.575, p=0.013) andCaucasians (A vs G: OR=0.591, 95%CI=0.361-0.966, p=0.036; AA+AG vs GG: OR=0.468, 95%CI=0.234-0.934,p=0.031). Conclusions: The results suggest that XRCC1 Arg399Gln polymorphism may increase HCC riskespecially among Asians. However, XRCC1 Arg399Gln polymorphism might act as a protective role againstHCC among Caucasians.     

XRCC1基因Arg399Gln多态性与中国人群神经胶质瘤易感性Meta分析

目的:探讨XRCC1基因Arg399Gln (G/A)多态性与中国人群神经胶质瘤易感性的关系.方法:计算机检索Pubmed、EMBASE、中国知网、万方期刊、维普等中英文数据库,检索2014年10月之前公开发表的相关文献,对符合标准的文献采用NOS量表评价文献质量,应用RevMan5.1软件进行Meta分析.结果:共纳入9篇与XRCC1基因Arg399Gln多态性与神经胶质瘤易感性相关的病例对照研究,包括7 131例患者,其中病例组3 428例,对照组3 703例,NOS评分≥6分为高质量文献,仅2项研究质量评分＜6.Meta分析结果显示携带A等位基因可增加中国人群神经胶质瘤的患病风险(OR=1.20,95％CI:1.04～1.38,P=0.01).结论:中国人群中XRCC1基因Arg399Gln (G/A)多态性与神经胶质瘤的易感性存在相关性.     

The XRCC1 399Gln polymorphism and the frequency of p53 mutations in Taiwanese oral squamous cell carcinomas.

DNA repair gene polymorphisms have been implicated as susceptibility factors in cancer development. It is possible that DNA repair polymorphisms may also influence the risk of gene mutation. The 399Gln polymorphism in the DNA repair gene XRCC1 has been indicated to have a contributive role in DNA adduct formation, sister chromatid exchange, and an increased risk of cancer development. Two hundred thirty-seven male oral squamous cell carcinomas (OSCCs) were included in a study to investigate the role of the XRCC1 194Trp, 280His, and 399Gln polymorphisms on p53 gene mutation. PCR-single-strand conformation polymorphism and DNA sequencing were used to analyze the conserved regions of the p53 gene (exons 5-9). The XRCC1 genotype was determined by PCR-RFLP. Nineteen (8.02%) of the 237 OSCCs had a Gln/Gln genotype. One hundred six (43.88%) of the 237 OSCCs showed p53 gene mutations at exons 5-9. The OSCC patients with a Gln/Gln genotype exhibited a significantly higher frequency of p53 mutation than those with an Arg/Gln and an Arg/Arg genotype. After adjustment for age, cigarette smoking, areca quid chewing, and alcohol drinking, the Gln/Gln genotype still showed an independent association with the frequency of p53 mutation (odd ratio, 4.50; 95% confidence interval, 1.52-13.36). The findings support the hypothesis that XRCC1 Arg399Gln amino acid change may alter the phenotype of the XRCC1 protein, resulting in a DNA repair deficiency. This study also suggests an important role for the XRCC1 399Gln polymorphism in p53 gene mutation in Taiwanese OSCCs.     

Association between XRCC1 Arg399Gln polymorphism and hepatitis virus-related hepatocellular carcinoma risk in Asian population

To investigate the association between X-ray repair cross-complementing group 1 (XRCC1) Arg399Gln polymorphism and hepatitis virus-related hepatocellular carcinoma risk, we performed a systematic meta-analysis of eligible case–control studies. Eligible studies were identified from the PubMed, Embase, and Chinese National Knowledge Infrastructure databases up to March 2013. The odds ratios (ORs) and corresponding 95 % confidence interval (95 % CI) of XRCC1 Arg399Gln polymorphism in hepatitis virus-related hepatocellular carcinoma cases compared with those in controls were calculated. The meta-analysis was performed using fixed-effect or random-effect methods according to the absence or presence of heterogeneity. This meta-analysis included 1,558 cases with hepatitis virus-related hepatocellular carcinoma and 1,338 controls. Meta-analysis of available data showed that there was no association between XRCC1 Arg399Gln polymorphism and risk of hepatitis virus-related hepatocellular carcinoma under all contrast models (Gln vs. Arg: fixed-effect OR?=?0.92, 95 % CI 0.82–1.04, P?=?0.18; GlnGln vs. ArgArg: random-effect OR?=?0.79, 95 % CI 0.50–1.25, P?=?0.32; GlnGln/ArgGln vs. ArgArg: fixed-effect OR?=?0.92, 95 % CI 0.79–1.07, P?=?0.28; and GlnGln vs. ArgArg/ArgGln: random-effect OR?=?0.83, 95 % CI 0.52–1.34, P?=?0.45). Sensitivity analysis further showed that there was no association between XRCC1 Arg399Gln polymorphism and risk of hepatitis B-related hepatocellular carcinoma under all contrast models (Gln vs. Arg: fixed-effect OR?=?0.93, 95 % CI 0.82–1.05, P?=?0.25; GlnGln vs. ArgArg: fixed-effect OR?=?0.86, 95 % CI 0.64–1.16, P?=?0.32; GlnGln/ArgGln vs. ArgArg: fixed-effect OR?=?0.93, 95 % CI 0.80–1.10, P?=?0.41; and GlnGln vs. ArgArg/ArgGln: fixed-effect OR?=?0.85, 95 % CI 0.63–1.13, P?=?0.26). Our meta-analysis of the available data did not find an obvious effect of XRCC1 Arg399Gln polymorphism on hepatitis-related hepatocellular carcinoma. More well-designed studies with large sample are needed to further verify the effect.     

A population-based study of the Arg399Gln polymorphism in X-ray repair cross- complementing group 1 (XRCC1) and risk of pancreatic adenocarcinoma

XRCC1 (X-ray repair cross-complementing group 1) is a base excision repair protein that plays a central role in the repair of DNA strand breaks and base damage from a variety of endogenous and exogenous oxidants including tobacco smoke. One genetic polymorphism (G-->A, Arg-->Gln at codon 399) occurs within a poly(ADP-ribose) polymerase binding region and within the central breast cancer susceptibility gene 1 product COOH terminus domain of XRCC1. The variant 399Gln allele of XRCC1 has been associated with elevated biomarkers of DNA damage in human cells. We conducted an analysis of the Arg399Gln polymorphism in XRCC1 using genomic DNA, and questionnaire information from 309 cases of pancreatic adenocarcinoma and 964 controls that were part of a population-based, case-control study conducted in the San Francisco Bay Area between 1994 and 2001. We genotyped individuals using a mass spectrometry-based method. Because smoking and obesity are known and suspected pancreas cancer risk factors, and have been associated with DNA damage and oxidative stress in target tissues, we estimated odds ratios (ORs), interaction contrast ratios (ICRs), and 95% confidence intervals for the combined effects of XRCC1 genotype and smoking or body mass index (in kg/m(2)). We also assessed potential gene-gene interactions between polymorphisms in XRCC1 and CYP1A1, GSTT1, and GSTM1. We found little or no evidence for an association between XRCC1 genotype and pancreatic cancer among Caucasians, African-Americans, or Asians. There was evidence for interaction between XRCC1 399Gln and smoking that was stronger among women than men. Relative to never active or passive smokers with the Arg/Arg genotype, the age- and race-adjusted ORs and ICRs (95% confidence limits) for heavy smoking (>or=41 pack-years) were: for Gln/Gln or Arg/Gln genotypes [women OR = 7.0 (2.4, 21), ICR = 3.1 (0.03, 6.2); men OR = 2.4 (1.1, 5.0), ICR = 1.3 (-0.20, 2.8)]; and for the Arg/Arg genotype [women OR = 2.2 (0.73, 6.4); men OR = 1.5 (0.68, 3.2)]. Analyses of combined genotypes suggested an interaction between XRCC1 (Gln/Gln or Arg/Gln) and GSTT1/GSTM1-null/null among women but not among men. There was no evidence of interaction between XRCC1 genotype and body mass index. Our results suggest that the XRCC1 399Gln allele is a potentially important determinant of susceptibility to smoking-induced pancreatic cancer. Our findings, including stronger associations and interactions among women, require replication in additional study populations.     

A population-based case-control study of the XRCC1 Arg399Gln polymorphism and susceptibility to bladder cancer.

Cigarette smoking is the major cause of bladder cancer. Constituents in tobacco smoke can induce oxidative DNA damage requiring base excision repair. The Arg399Gln polymorphism in the DNA base excision repair gene XRCC1 is associated with several phenotypic markers of reduced DNA repair capacity. Results from several epidemiologic studies suggest that the Arg399Gln polymorphism may influence susceptibility to several cancers including bladder cancer; however, data from large population-based studies are lacking. In a population-based case-control study from New Hampshire, we observed a reduced risk among those homozygous for the Arg399Gln XRCC1 variant polymorphism compared with those with one or two wild-type alleles (odds ratio 0.6, 95% confidence interval 0.4-1.0). There was no indication of a gene-environment interaction between cigarette smoking and the variant genotype. Our data are consistent with a potential role of the XRCC1 Arg399Gln polymorphism in bladder cancer susceptibility and further suggest that there may be DNA lesions important in bladder carcinogenesis, repaired by the base excision repair mechanism, that are not directly associated with tobacco smoking.     

X-ray repair cross-complementing group 1 Arg399Gln gene polymorphism and susceptibility to colorectal cancer:a meta-analysis

X-ray repair cross-complementing group 1 (XRCC1), a DNA repair enzyme, plays a crucial role in the base excision repair by generating a single nucleotide repair patch. It has been demonstrated that the XRCC1 Arg399Gln gene polymorphism was associated with variations in XRCC1 enzyme activity. The aim of this study was to quantitatively summarize the association between the XRCC1 Arg399Gln polymorphism and susceptibility to colorectal cancer (CRC). A comprehensive search of the PubMed, Embase, and China National Knowledge Infrastructure databases was conducted for studies on the association between the XRCC1 Arg399Gln polymorphism and CRC risk. Summary odds ratio (OR) with its corresponding 95 % confidence interval (95 %CI) was estimated, in a fixed-effects model or a random-effects model when appropriate, to assess the association. Totally, 26 case–control studies with 6,979 cases and 11,470 controls were included into this meta-analysis. The pooled results of total studies showed that the XRCC1 Arg399Gln polymorphism was significantly associated with increased risk of CRC in all genetic contrast models (OR_{A vs. G}?=?1.13, 95 %CI 1.03–1.23, P _OR?=?0.008; OR_{Gln/Gln vs. Arg/Arg}?=?1.24, 95 %CI 1.04–1.46, P _OR?=?0.015; OR_{Gln/Gln vs. Arg/Gln + Arg/Arg}?=?1.19, 95 %CI 1.03–1.38, P _OR?=?0.021; OR_{Gln/Gln + Arg/Gln vs. Arg/Arg}?=?1.14, 95 %CI 1.02–1.28, P _OR?=?0.022), except for the additive contrast model (OR_{Arg/Gln vs. Arg/Arg}?=?1.11, 95 %CI 0.99–1.25, P _OR?=?0.064). The statistically significant association between the XRCC1 Arg399Gln polymorphism and CRC risk was observed among studies with high quality and in Asians, but not in Caucasians. Sensitivity analyses by sequential omission of any individual studies further identified the significant association. Publication bias was inexistent in this meta-analysis. The meta-analysis suggests that the XRCC1 Arg399Gln polymorphism is associated with increased risk of CRC.     

Inheritance of the 194Trp and the 399Gln variant alleles of the DNA repair gene XRCC1 are associated with increased risk of early-onset colorectal carcinoma in Egypt

Patients under age 40 constitute 35.6% of all colorectal cancer cases in Egypt, an unusual disease pattern to which both environmental exposures and inefficient DNA repair may contribute. While a number of polymorphisms in DNA repair genes have been recently identified, their role as cancer risk modifiers is yet to be determined. In a pilot case-control study, we tested the hypothesis that polymorphisms in the gene for the DNA repair enzyme XRCC1 are associated with increased risk of colorectal cancer among Egyptians. Using a multiplex polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology, allelic variants of the XRCC1 gene at codons 194 (Arg-->Trp) (194Trp) and 399 (Arg-->Gln) (399Gln), were analyzed in DNA from lymphocytes of 48 newly-diagnosed colorectal cancer cases and 48 age- and sex-matched controls. Overall, the inheritance of 194Trp allele (Arg/Trp genotype) and 399Gln allele (combined Arg/Gln and Gln/Gln genotypes) was associated with increased colorectal cancer risk (odds ratio (OR)=2.56, 95% confidence limits (CL) 0.73-9.40, and P=0. 08 for 194Trp allele and OR=3.98, 95% CL 1.50-10.6, and P<0.001 for 399Gln allele). Interestingly, the frequencies of 194Trp and 399Gln genotypes were higher in colorectal cancer cases under age 40 than in corresponding controls, and an association between both polymorphisms and early age of disease onset was observed (OR=3.33, 95% CL 0.48-35.90, and P=0.16 for 194Trp and OR=11.90, 95% CL 2.30-51.50, and P=0.0003 for 399Gln). Analysis of the data after adjustment for place of residence indicated that the frequencies of the genotypes with the 194Trp and the 399Gln alleles were higher among urban residents (OR=3.33, 95% CL 0.48-35.90, and P=0.16 for 194Trp and OR=9.97, 95% CL 1.98-43.76, and P<0.001 for 399Gln) than among rural residents (OR=2.00, 95% CL 0.36-26.00, and P=0.30 for 194Trp and OR=1.90, 95% CL 0.50-7.53, and P=0.20 for 399Gln). These findings support our hypothesis and suggest that polymorphisms in the XRCC1 gene, in conjunction with place of residence, may modify disease risk. This first demonstration that polymorphisms in DNA repair genes may contribute to colorectal cancer susceptibility and may increase the risk of early onset of the disease opens the door for future studies in that direction.     

XRCC 1 Arg399Gln基因多态性对铂类药物化疗胃癌患者预后的影响

目的：研究DNA修复酶X射线损伤交叉互补蛋白1（X-ray repair cross-complementary protein1，XRCCl）基因Arg399Gln多态性对接受铂类药物辅助化疗的胃癌患者预后的影响。方法：选取经病理学确诊的胃癌患者84例，采用含铂类药物的联合化疗方案进行辅助化疗。化疗前采集患者外周血，采用聚合酶链反应．连接酶检测反应（polymerase chain reaction-ligation detection reaction，PCR-LDR）技术检测XRCCl基因Arg399Gln的多态性。结果：84例胃癌患者中，49例（58．3％）携带XRCCl的399Axg／Arg基因型，30例（35．7％）携带Arg／Gln基因型，5例（6．0％）携带Gin／Gin基因型；截止到随访结束，分别有63．1％（53／84）和55．2％（43／84）的患者出现复发和死亡，其中携带Arg／Arg基因型的胃癌患者复发率和死亡率均显著低于携带Arg／Gln或Gln／Gln基因型患者（P〈0.05）。COX多因素分析显示，携带Arg／Arg基因型的患者具有较好的无复发生存期和总生存期预后（P〈0．05）。结论：XRCClArg399Gln基因多态性与术后胃癌患者接受铂类药物化疗后的预后有关，可以在一定程度上判断术后胃癌患者接受铂类药物化疗的预后情况。     

The XRCC1 Arg399Gln polymorphism, sunburn, and non-melanoma skin cancer: evidence of gene-environment interaction.

XRCC1, a protein directly involved in the repair of DNA base damage, contains at least three common polymorphisms. One of these, the codon 399 arg-->gln variant, has been associated with several cancer-related biomarkers, suggesting it may have functional significance in exposure-induced cancers. However, results from case-control studies have yielded conflicting results. We investigated the XRCC1 arg399gln polymorphism and its interaction with carcinogen exposure in a large, population-based case-control study of non-melanoma skin cancer. Cases were derived from an incident survey of all newly diagnosed non-melanoma skin cancer in New Hampshire, and controls were population based and frequency matched to cases on age and sex (n = 1176). Exposure information was derived from a detailed interviewer-administered questionnaire, and XRCC1 genotype was determined from blood-derived DNA using a PCR-RFLP method. Overall, the XRCC1 homozygous variant gln399gln genotype was related to a significantly reduced risk of both basal cell [BCC; odds ratio (OR) 0.7, 95% confidence interval 0.4-1.0] and squamous cell carcinoma (SCC; OR 0.6, 95% confidence interval 0.3-0.9). There was no significant gene-environment interaction of the variant XRCC1 genotype and a history of therapeutic X-ray exposure. However, there was a statistically significant multiplicative interaction of XRCC1 genotype and lifetime number of sunburns in SCC [likelihood ratio test (2 d.f.), P < 0.02]. Although the absolute risk of SCC associated with sunburns was similar across genotypes, the relative risk of SCC associated with painful sunburn history was significantly higher for homozygous variants than wild types (OR 6.8 for gln399gln and 1.5 for arg399arg). In summary, our data show that the homozygous XRCC1 variant (gln399gln) is associated with a lower risk of non-melanoma skin cancer and suggest that the etiology of sunburn-related SCC may be significantly different by XRCC1 genotype. These data, using the classic skin carcinogenesis model, provide new insight on the role of the XRCC1 399 polymorphism in neoplasia and may help explain the conflicting results relating this polymorphism to cancer risk at various sites.     

XRCC1 Arg399Gln基因多态性与中国人群肝细胞癌易感性的Meta分析

目的 探讨XRCC1 Arg399Gln基因多态性与肝细胞癌（HCC）易感性的关系。方法 计算机检索PubMed、中国生物医学文献（CBM）、中国知网、万方及维普等数据库,收集有关XRCC1 Arg399Gln基因多态性与HCC易感性关系的病例对照研究,提取纳入文献的相关数据进行Meta分析,以病例组与对照组XRCC1 Arg399Gln各种基因模型的比值比（OR）为效应指标,发表偏倚采用Eggers检验和Beggs检验。结果 共17篇文献符合纳入标准,累计病例数3301例,对照组4156例。XRCC1 Arg399Gln基因多态性与中国人群HCC易感性有明显关联性（G/G vs. A/A：OR=1.32,95％CI：1.13～1.54,P=0.000;A/G vs. A/A：OR=1.25,95％CI：1.10～1.41,P=0.000;A/G+G/G vs. A／A：OR=1.22,95％CI：1.09～1.36,P=0000;G／G vs. A／A+A／G：OR=1.20,95％CI：1.04～1.39,P=0.014）。根据健康对照组来源不同的亚组分析中,所有地区或者控制人口来源医院的研究结果均显示,XRCC1 Arg399Gln 基因多态性与HCC易感性有明显关联性,但控制人口非医院来源的研究结果显示XRCC1 Arg399Gln 基因多态性与HCC易感性无明显关联性;根据地区不同分组的亚组分析中,在广西地区,除隐性遗传模型外（G/G vs. A/A+A/G：OR=1.25,95％CI：0.95～1.65,P=0.115）,其余遗传模型结果显示XRCC1 Arg399Gln基因多态性与广西地区HCC易感性有明显相关性（G/G vs. A/A：OR=1.47,95％CI：1.10～1.95,P=0.009;A/G vs. A/A：OR=1.35,95％CI：1.17～1.56,P=0.000;A/G+G/G vs.A／A：OR=133,95％CI：1.16～1.52,P=0.000）。结论 XRCC1 Arg399Gln 基因多态性可能增加中国人群HCC的易感性,尤其在广西地区。     

The Codon 399 Arg/Gln XRCC1 Polymorphism is Associated with Lung Cancer in Indians

Background: The XRCC1 (X-ray repair cross complimenting group-I) gene in BER (base excision repair)pathway is essential for DNA repair process. Polymorphisms in this gene are associated with variations in the repairefficiency which might predispose individuals to development of various cancers. Two variants of XRCC1gene(at codon 399), Gln/Gln and Arg/Gln, have been shown to be related to lowered DNA repair capacity andincreased genomic instability in multiple studies. Hence our investigation focused on genotyping these variantsto correlate with other multiple risk factors in lung cancer (NSCLC) patients since we hypothesized that thesevariants of the XRCC1 gene might influence disease susceptibility. Materials and Methods: We examined thefrequency of the polymorphism in one hundred cases and an almost equal number of controls after recordingtheir demographics with a structured questionnaire. Genomic DNA from blood samples was extracted for PCRstudies, followed by RFLP to determine the variants. The significance of the data was statistically analyzed.Results: The three genotypes in cases and controls were Arg/Arg (40% and 54.45%); Gln/Gln (19% and 9.90%),and Arg/Gln (41.0% and 35.64%) respectively. Among these 3 genotypes, we found Gln/Gln and Arg/Gln toshow association with lung cancer. Correlating these genotypes with several parameters, we also found that thesetwo variants were associated with risk in males (p<0.05) and with smoking habits (p<0.05). In females Arg/Glngenotype showed association with stage of the disease (p=0.04). This is the first report in South Indian scenariowhere Arg399Gln genotypes were found to be associated with stage of the disease in females. Conclusions: Itis concluded that XRCC1 genotypes Gln/Gln and Arg/Gln may influence cancer susceptibility in patients withsmoking habits and these functional SNPs in XRCC1 gene may act as attractive candidate biomarkers in lungcancer for diagnosis and prognosis.     

DNA repair gene hOGG1 codon 326 and XRCC1 codon 399 polymorphisms and bladder cancer risk in a Japanese population

Background: Bladder cancer is the most common urologic malignancy in theUSA. Tobacco smoking generates oxidative DNA damage and inducesbladder cancer. Base excision repair (BER) is a very importantmechanism for repairing oxidative DNA damage. There are manyenzymes involved in BER. Human oxoguanine glycosylase 1 (hOGG1)and X-ray repair cross-complementing 1 (XRCC1) are enzyme genesof BER. Actually, the hOGG1 codon 326 polymorphism was associatedwith the risk of lung oesophagus and stomach cancer. On theother hand, among several XRCC1 gene polymorphisms, codon 399polymorphism was reported to reduce the risk of bladder cancerand raise the risk of lung cancer. Methods: We examined the association between the genetic polymorphismsof hOGG1 codon 326 and XRCC1 codon 399 and bladder cancer risk.In this study, we recruited 251 bladder cancer cases and 251healthy controls to evaluate the effect of hOGG1 codon 326 andXRCC1 codon 399 polymorphisms on bladder cancer. We detectedgenotypes by the polymerase chain reaction–restrictionfragment length polymorphism (PCR–RFLP) method. Results: The frequencies of the hOGG1 codon 326 genotypes Cys/Cys wassignificantly higher in the cases than in the controls. Adjustedodds ratio (OR) was 1.85 (95% CI: 1.12–3.03; p = 0.02)compared with Ser/Ser, and was 2.05 (95% CI: 1.36–3.08;p = 0.01) compared with Ser/Ser + Ser/Cys. In addition, whenevaluated with smoking status, the adjusted OR (Cys/Cys versusSer/Ser + Ser/Cys) ran up to 2.78 (95% CI: 1.39–5.60;p < 0.01) among non-smokers. For the XRCC1 polymorphism,the Gln/Gln of XRCC1 codon 399 genotype was statistically higherin the controls than in the cases though compared with Alg/Alg+ Alg/Gln. The adjusted OR was 0.45 (95% CI: 0.21–0.99;p = 0.05), and was lifted up to 0.37 (95% CI: 0.14–0.98;p = 0.05) among smokers. Conclusion: It is indicated that the hOGG1 codon 326 and XRCC1 codon 399polymorphisms are risk factors of bladder cancer.