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.     

Updated Assessment of the Association of the XRCC1 Arg399Gln Polymorphism with Lung Cancer Risk in the Chinese Population

Background: Published studies have reported relationships between X-ray repair cross-complementing group1 (XRCC1) Arg399Gln polymorphism and lung cancer risk in Chinese population. However, the epidemiologicalresults remained controversial. The objective of this study was to clarify the association of XRCC1 Arg399Glnpolymorphism with lung cancer risk in the Chinese population. Materials and Methods: Systematic searches wereperformed through the database of Medline/Pubmed, Web of Science, Embase, CNKI and WanFang MedicalOnline. Odds ratios (ORs) with 95% confidence interval (95%CI) were calculated to estimate the strength ofthe association. Results: Overall, we observed an increased lung cancer risk among subjects carrying XRCC1codon 399 Gln/Gln genotype (OR=1.36, 95%CI: 1.09-1.71) in the Chinese population on the basis of 19 studieswith 5,416 cases and 5,782 controls. We did not observe any association between XRCC1 codon 399 Arg/Gln andArg/Gln+Gln/Gln polymorphisms and lung cancer risk (OR=1.00, 95%CI: 0.92-1.08 and OR=1.05, 95%CI: 0.97-1.13, respectively). Limiting the analysis to studies with controls in agreement with Hardy-Weinberg equilibrium(HWE), we observed an increased lung cancer risk among subjects carrying XRCC1 codon 399 Gln/Gln genotype(OR=1.18, 95%CI: 1.01-1.38). When stratified by source of control, we observed an increased lung cancer riskamong subjects carrying XRCC1 codon 399 Arg/Gln+Gln/Gln genotype on the basis of hospitalized patient-basedcontrols (OR=1.21, 95%CI: 1.04-1.42) and among subjects carrying XRCC1 codon 399 Gln/Gln genotype onthe basis of healthy subject-based controls (OR=1.22, 95%CI: 1.04-1.43). Conclusions: Our findings indicatedthat certain XRCC1 Arg399Gln variants might affect the susceptibility of lung cancer in Chinese population.Larger sample size studies are required to confirm our findings.     

DNA repair gene XRCC1 polymorphisms, smoking, and esophageal cancer risk

To investigate the effect of X-ray repair cross complementing 1 (XRCC1) genetic polymorphisms on esophageal cancer risk, we determined XRCC1 polymorphisms at codon 194 (Arg --> Trp) and codon 399 (Arg --> Gln) in 135 patients with esophageal squamous cell carcinoma (ESCC) and 152 normal controls from hospitals. Although polymorphism at codon 194 was not associated with risk for ESCC, we found that the frequency of XRCC1 399 Gln/Gln genotype in ESCC patients (14.1%) was significantly higher than that in normal controls (3.3%), and that XRCC1 399 Gln/Gln genotype was associated with an increased risk of ESCC (odds ratio (OR) = 5.15, 95% confidence interval (CI): 2.42-0.93). In addition, we found that the risk for smoker increased 4.2-fold than non-smokers in the 399 Gln/Gln genotype (OR = 4.20, 95% CI: 2.37-7.44). These results suggest that XRCC1 399 Gln/Gln genotype may contribute to the risk of ESCC and modify risk associated with smoking.     

Polymorphisms in XRCC1 modify the association between polycyclic aromatic hydrocarbon-DNA adducts, cigarette smoking, dietary antioxidants, and breast cancer risk.

The variability in DNA repair capacity of the general population may depend in part upon common variants in DNA repair genes. X-ray repair cross complementing group 1 (XRCC1) is an important DNA base excision repair gene and exhibits polymorphic variation. Using the Long Island Breast Cancer Study Project, a population-based case-control study, we evaluated the hypothesis that two common single nucleotide polymorphisms of XRCC1 (codon 194 Arg-->Trp and 399 Arg-->Gln) influence breast cancer susceptibility and interact with polycyclic aromatic hydrocarbon (PAH)-DNA adducts, cigarette smoking, and intake of fruits and vegetables and antioxidants. The available sample for genotyping included 1,067 cases and 1,110 controls. Genotyping was done by a high-throughput single-nucleotide extension assay with fluorescence polarization detection of the incorporated nucleotide. We observed no significant increases in risk among all subjects who were carriers of XRCC1 194Trp or 399Gln alleles. Among never smokers, we observed an increased risk of breast cancer in 399Gln carriers [odds ratio (OR), 1.3; 95% confidence interval (CI), 1.0-1.7). Further analysis indicated a suggestive weak additive interaction between the 399Gln allele and detectable PAH-DNA adducts (OR for exposure with mutant genotype, 1.9; 95% CI, 1.2-3.1). The estimated age-adjusted interaction contrast ratio (ICR) and 95% CI (ICR, 0.38; 95% CI, -0.32 to 1.10) indicated that the departure from additivity was not statistically significant, but that there was some suggestion of a relative excess risk due to the interaction. In subjects with at least one copy of XRCC1 194Trp allele, there was a moderate interaction with high intake of fruits and vegetables (>/=35 half-cup servings per week of any fruits, fruit juices, and vegetables, OR, 0.58; 95% CI, 0.38-0.89; ICR, -0.49; 95% CI, -0.03 to -0.95), and dietary plus supplement antioxidant intake with 33% to 42% decreases in breast cancer risk compared with those with the Arg194Arg genotype and low-intake individuals. These results do not show that the two genetic polymorphisms of XRCC1 independently influence breast cancer risk. However, there is evidence for interactions between the two XRCC1 single nucleotide polymorphisms and PAH-DNA adducts or fruit and vegetable and antioxidant intake on breast cancer risk. Further understanding of the biological function of XRCC1 variants and their interactions with PAH-DNA adducts, antioxidants, and other genes in the pathway are needed.     

A prospective study of XRCC1 (X-ray cross-complementing group 1) polymorphisms and breast cancer risk

Introduction

The gene XRCC1 (X-ray repair cross-complementing group 1) encodes a protein involved in DNA base excision repair. Two non-synonymous polymorphisms in XRCC1 (Arg194Trp and Arg399Gln) have been shown to alter DNA repair capacity in some studies in vitro. However, results of previous association studies of these two XRCC1 variants and breast cancer have been inconsistent. We examined the association between polymorphisms in XRCC1 and breast cancer in the American Cancer Society Cancer Prevention Study II (CPS-II) Nutrition Cohort, a large prospective study of cancer incidence in the USA.

Methods

Among the 21,965 women who were cancer-free in 1992 and gave blood between 1998 and 2001, 502 postmenopausal breast cancer cases were diagnosed between 1992 and 2001; 502 controls were matched to cases on age, race/ethnicity, and date of blood collection. Genotyping on DNA extracted from buffy coat was performed with Taqman. Conditional logistic regression was used to examine the association between each polymorphism and breast cancer risk controlling for breast cancer risk factors. We also examined whether factors associated with DNA damage, such as smoking and antioxidant intake, modified the association between XRCC1 polymorphisms and breast cancer.

Results

We observed a significant inverse association between Trp194 carriers (Trp/Trp and Trp/Arg) compared with Trp194 non-carriers in relation to breast cancer (Arg/Arg) (odds ratio (OR) 0.62, 95% confidence interval (CI) 0.40 to 0.95). The inverse association between breast cancer and Trp194 carriers compared with non-carriers was slightly stronger among smokers (OR 0.47, 95% CI 0.24 to 0.94) than never smokers (OR 0.78, 95% CI 0.43 to 1.40). An increased risk associated with the Arg399Gln polymorphism (Gln/Gln versus Arg/Arg) was observed only among women who reported ever smoking cigarettes (OR 2.76, 95% CI 1.36 to 5.63), and not in women who were lifelong non-smokers (OR 0.64, 95% CI 0.33 to 1.26). No other factor examined modified the association between XRCC1 polymorphisms and breast cancer risk.

Conclusion

Our results support the hypothesis that genetic variation in XRCC1, particularly in Arg194Trp, may influence postmenopausal breast cancer risk. In our study, genetic variation in XRCC1 Arg399Gln was associated with breast cancer risk only among women with a history of smoking cigarettes.     

DNA repair single-nucleotide polymorphisms in colorectal cancer and their role as modifiers of the effect of cigarette smoking and alcohol in the Singapore Chinese Health Study.

Recently, we reported that among Singapore Chinese, cigarette smoking and alcohol drinking were independent risk factors for colorectal cancer. Both tobacco smoking and alcohol use are plausible colorectal cancer risk factors, partly due to their ability to induce mutations in the colorectal lumen. In the present study, we investigated the role in colorectal cancer of single-nucleotide polymorphisms in five DNA repair genes: XRCC1 (Arg(194)Trp and Arg(399)Gln), PARP (Val(762)Ala, Lys(940)Arg), XPD (Asp(312)Asn, Lys(751)Gln), OGG1 (Ser(326)Cys), and MGMT (Leu(84)Phe). We conducted this study within the Singapore Chinese Health Study, a population-based cohort of 63,257 middle-aged and older Singapore Chinese men and women enrolled between 1993 and 1998. Our study included 1,176 controls and 310 cases (180 colon and 130 rectum cancer). We observed a positive association between the PARP codon 940 Lys/Arg and Arg/Arg genotypes and colorectal cancer risk [odds ratio (OR), 1.8; 95% confidence interval (95% CI), 1.1-3.1], and an inverse association between the MGMT codon 84 Leu/Phe or Phe/Phe genotypes and colon cancer risk (OR, 0.6; 95% CI, 0.3-0.9), but not rectal cancer (test of heterogeneity by tumor site, P=0.027). We observed evidence that XRCC1 may modify the effects of smoking (interaction P=0.012). The effect of smoking among carriers of the Arg(194)-Gln(399) haplotype was OR=0.7 (95% CI, 0.4-1.1), whereas, among carriers of the Trp(194)-Arg(399) haplotype, it was OR=1.6 (95% CI, 1.1-2.5). We also observed a nonstatistically significant modification of XRCC1 on the effects of alcohol (P=0.245). Whereas alcohol had no effect among carriers of the codon 194 Arg/Arg (OR, 1.0; 95% CI, 0.6-1.7) or Arg/Trp genotypes (OR, 1.1; 95% CI, 0.6-1.9), there was a positive association among carriers of the Trp/Trp genotype (OR, 2.8; 95% CI, 1.0-8.1). Our results support a role for reactive oxygen species as relevant genotoxins that may account for the effects of both smoking and alcohol on colorectal cancer risk.     

XRCC1 polymorphisms, cooking oil fume and lung cancer in Chinese women nonsmokers

X-ray repair cross-complementing group 1 (XRCC1) is one of the major DNA repair proteins involved in the base excision repair (BER) and single-strand break repair (SSBR) pathway. Single nucleotide polymorphisms (SNPs) in XRCC1 may alter protein function and repair capacity, thus lead to genetic instability and carcinogenesis. To establish our understanding of possible relationships between XRCC1 polymorphisms (5'UTR -77T>C, Arg194Trp, Arg280His and Arg399Gln) and the susceptibility to lung cancer among women nonsmokers, we performed a hospital-based case-control study of 350 patients with newly diagnosed lung cancer and 350 cancer-free controls, frequency matched by age. Our results showed that exposure to cooking oil fume was associated with increased risk of lung cancer in Chinese women nonsmokers [odds ratio (OR)=2.51, 95% confidence interval (CI) [1.80-3.51], P<0.001]. Individuals with homozygous XRCC1 399Gln/Gln genotype (OR=1.75, 95% CI [1.02-3.01]) and XRCC1 -77 combined TC and CC genotype (OR=1.66, 95% CI [1.13-2.42]) showed a slightly higher risk for lung cancer overall. In the subgroup of adenocarcinoma cases, adjusted ORs were increased for individuals with homozygous XRCC1 399Gln/Gln genotype (OR=2.62, 95% CI [1.44-4.79]) and XRCC1 -77 combined TC and CC genotype (OR=1.85, 95% CI [1.19-2.86]). Haplotype analysis showed that T-Trp-Arg-Gln haplotypes were associated with an increased risk of lung cancer among women nonsmokers (OR=2.26, 95% CI [1.38-3.68]), however, we did not observe a statistically significant joint effect of cooking oil fume and 399Gln or -77C variant allele on lung cancer among women nonsmokers. In conclusion, XRCC1 Arg399Gln and T-77C polymorphisms may alter the risk of lung cancer in women nonsmokers in China.     

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, XRCC3, and XPD polymorphisms as modifiers of the effect of smoking and alcohol on colorectal adenoma risk.

Using a sigmoidoscopy-based case-control study (753 cases, 799 controls) in Los Angeles County, we investigated the potential modifier role in the effect of alcohol and smoking of single-nucleotide polymorphisms (SNP) in three DNA repair genes, XRCC1 (Arg194Trp and Arg399Gln), XRCC3 (Thr241Met), and XPD (Lys751Gln). We have previously reported an inverse association between the XRCC1 codon 399 SNP and adenoma risk among these subjects. We now report that subjects with the XPD Gln/Gln genotype were inversely associated with adenoma risk [odds ratio (OR), 0.7; 95% confidence interval (95% CI), 0.5-1.0] when compared with subjects with the Lys/Lys and Lys/Gln genotypes combined. This association differed between different ethnic groups (gene x race heterogeneity likelihood ratio test, P = 0.009), with a stronger inverse association among Latinos (OR, 0.1; 95% CI, 0.01-0.5) than among non-Latinos (OR, 0.9; 95% CI, 0.-1.3). We found no evidence of an XRCC3 x smoking or alcohol interaction or an XRCC1 x alcohol interaction. Instead, our data supported an XRCC1 x smoking interaction (P = 0.048). Whereas XPD did not modify the effect of smoking, our data suggested an XPD x alcohol interaction. Analyses ignoring XPD showed no association between alcohol intake and adenoma prevalence; however, among carriers of the codon 751 Gln/Gln genotype, we found a significant positive association (OR, 2.5; 95% CI, 1.2-5.2 for ever drinkers; test of interaction P = 0.04). Our data suggest that the effects of smoking and alcohol may vary depending on the genetic background of proteins that participate in the base excision repair and nucleotide excision repair pathways.     

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.     

XRCC1基因多态性与卵巢癌对铂类药物化疗敏感性的相关性研究

目的 探讨X线修复交叉互补基因1（XRCC1）Arg194Trp和Arg399Gln位点多态性与卵巢癌对铂类药物化疗敏感性之间的关系。方法 选取82例首次术后以铂类为基础化疗达6个周期的卵巢癌患者,采用聚合酶链反应 限制性片段长度多态性分析（PCR RFLP）检测外周血XRCC1 Arg194Trp和Arg399Gln位点的基因型,分别比较两个位点的不同基因型与化疗敏感性及两个位点之间的关系。结果 XRCC1 Arg194Trp存在3个基因型,即Arg／Arg、Arg／Trp、Trp／Trp,基因分布频率分别为47.6％、43.9％、8.5％;XRCC1 Arg399Gln亦存在3个基因型,即Arg／Arg、Arg／Gln、Gln／Gln,基因分布频率分别为25.6％、40.2％、34.1％。XRCC1 Arg399Gln 的不同基因型在FIGO分期和年龄分组中的差异均有统计学意义（P＜0.05）。化疗敏感组与不敏感组两个位点多态性基因型之间的差异均有统计学意义（P＜0.05）。XRCC1 Arg194Trp的Trp／Trp和Arg 399Gln的Gln/Gln基因型比Arg／Arg基因型更易对铂类药物产生耐药性,比值比分别增加至13.50倍（95％CI：1.461～124.739）和7.65倍（95％CI：2.012～29.088）。同时携带Arg194Trp Arg／Trp和Arg399Gln Gln／Gln基因型的患者对化疗不敏感率高达84.62％（OR=22.00,95％CI：2.534～190.998;P＜0.05）。结论 XRCC1 Arg194Trp和Arg399Gln位点基因多态性与卵巢癌对铂类药物的化疗敏感性相关,并且两位点之间存在联合效应。     

XRCC1 codon 399 mutant allele: a risk factor for recurrence of urothelial bladder carcinoma in patients on BCG immunotherapy

XRCC1 protein plays crucial role in base excision repair (BER)by acting as a scaffold for other BER enzymes. Variants in XRCC1 gene might alter protein structure/function or create alternatively spliced protein influencing BER efficiency and affect individual susceptibility/recurrence to urinary bladder cancer (BC). We tested whether polymorphisms in XRCC1 gene were associated with BC risk and further to substantiate risk of recurrence after Bacillus Calmette-Guerin (BCG) immunotherapy. Genotyping for three polymorphic sites of XRCC1 gene at codon Arg194Trp (PvuII), Arg280His (RsaI) and Arg399Gln (MspI) in 140 BC cases and 190 controls by PCR-RFLP method was done. We observed significant association in heterozygous genotype (GA) of codon 280 and 399 with BC risk (OR = 1.96, p = 0.021 and OR = 1.81, p = 0.021, respectively), however no association was seen for variant AA genotype. A trend of increased risk with high stage and grade in patients with codon 194 variant genotypes (CT + TT) was observed. Haplotype analysis showed that individuals with haplotype 194C-280G-399A were at >3-fold higher risk for BC (OR = 3.48, p = 0.01). The A/A genotype of codon 399 was associated with high risk for recurrence in BCG treated patients (HR = 5.05, p = 0.01) thus, showing reduced recurrence free survival (AA/GG = 12/60 months; log rank p = 0.004). The study suggested no association of variant genotypes with the susceptibility to BC. Haplotype analysis however, revealed that XRCC1 399 A allele may have a major role as patients with haplotype 194C-280G-399A carrying variant allele of 399 were at higher risk.     

XRCC1单核苷酸多态性与鼻咽癌铂类化疗敏感度的相关性

目的 探讨鼻咽癌铂类化疗敏感度与X射线交错互补修复基因1 codon194和codon399单核苷酸多态性的相关性。方法 收集广西医科大学第四附属医院2012年9月1日至2013年12月31日鼻咽部肿物活检确诊为鼻咽癌患者资料,采用限制性片段长度多态性聚合酶链反应技术检测鼻咽癌患者外周血DNA XRCC1 codon194和codon399单核苷酸多态性。顺铂+氟尿嘧啶方案诱导化疗2周期后复查MRI,按照RECIST 1.1标准评价其化疗敏感度,分析单核苷酸多态性（Single nucleotide polymorphism,SNP）与化疗敏感度的关系。结果 XRCC1 codon399 Gln/Gln基因型携带者化疗敏感度为Arg/Arg基因型携带者的3.500倍（P＜0.05）。XRCC1 codon399不含Arg基因型（即Gln/Gln）携带者化疗敏感度为含Arg基因型（Arg/Arg 和 Arg/Gln）携带者的3.274倍,（P＜0.05）。携带XRCC1 codon194各基因型患者化疗敏感度之间差异无明显统计学意义（P＞0.05）。结论 XRCC1 codon399 单核苷酸多态性有可能成为鼻咽癌铂类化疗敏感度的预测因子。     

Association of the Arg194Trp and the Arg399Gln Polymorphisms of the XRCC1 Gene With Risk Occurrence and the Response to Adjuvant Therapy Among Polish Women With Breast Cancer

BackgroundThe XRCC1 gene encoding the X-ray cross-complementing group 1 protein (XRCC1) is involved in the base excision repair (BER) pathway.MethodsThe aim of this study was to investigate an association of the Arg194Trp and Arg399Gln polymorphisms of the XRCC1 gene with a risk of breast cancer occurrence and the response to adjuvant treatment among Polish women. Overall survival (OS) and disease-free survival (DFS) were investigated in groups of patients with breast cancer treated with (1) all types of adjuvant therapy, (2) concomitant radiotherapy and chemotherapy, (3) chemotherapy alone, or (4) radiotherapy alone. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) was used to evaluate the genotype distribution of the XRCC1 gene among 185 patients with breast cancer and 205 female controls.ResultsWe showed a higher risk of breast cancer occurrence for the Trp allele and the Arg194Trp genotype of the XRCC1 gene. However there was no significant difference in distribution of the Arg399Gln genotype of XRCC1 between patients and the control group. In the patient subgroup treated with adjuvant therapy, Kaplan-Meier survival analysis showed a significantly higher OS as well as DFS for carriers of the Gln399Gln genotype when compared with carriers of the Arg399Gln and Arg399Arg genotypes. The Gln399Gln genotype was associated with a significantly higher DFS in the subgroup of patients treated with chemotherapy alone or with concomitant radiotherapy and chemotherapy.ConclusionWe suggest that the polymorphism of the XRCC1 gene may be considered a predictive factor associated with the risk of occurrence and the survival outcome in breast cancer among Polish women.     

The association of XRCC1 gene single nucleotide polymorphisms with response to neoadjuvant chemotherapy in locally advanced cervical carcinoma

Background

Platinum-based neoadjuvant chemotherapy (NAC) is new therapeutic strategy for locally advanced cervical carcinoma, but the variables used to predict NAC response are still infrequently reported. The aim of our study was to investigate the association between XRCC1 gene single nucleotide polymorphisms (SNPs) and NAC response.

Methods

Seventy patients with locally advanced cervical carcinoma who underwent NAC were collected. SNPs of XRCC1 (at codon 194 and 399) and XRCC1 protein expression were detected. The association of XRCC1 gene SNPs and protein expression with NAC response were analyzed.

Results

Response to NAC was not statistically significant in three genotypes, Arg/Arg, Arg/Trp, Trp/Trp of XRCC1 at codon 194(X² = 1.243, P = 0.07), while responses were significantly different in genotypes Arg/Arg, Arg/Gln, Gln/Gln of XRCC1 at codon 399 (X² = 2.283, P = 0.020). The risk of failure to chemotherapy in the patients with a Gln allele(Arg/Gln+Gln/Gln) was significantly greater than that with Arg/Arg(OR = 3.254, 95%CI 1.708 ~ 14.951). The expression level of XRCC1 protein was significantly associated with response to NAC. Moreover, the genotype with the Gln allele(Arg/Gln+Gln/Gln) at codon 399, but not codon at 194, presented a significantly higher level of XRCC1 protein expression than that with Arg/Arg genotype (F = 2.699, p = 0.009).

Conclusion

SNP of XRCC1 gene at codon 399 influences the response of cervical carcinoma to platinum-based NAC. This is probably due to changes in expression of XRCC1 protein, affecting response to chemotherapy.     

XRCC1 and XRCC3 polymorphisms and their role as effect modifiers of unsaturated fatty acids and antioxidant intake on colorectal adenomas risk.

Whereas animal and in vitro studies support a role of unsaturated fatty acids in colon carcinogenesis, the epidemiologic evidence is inconclusive. Using a large sigmoidoscopy-based case-control study (753 cases and 799 controls) in Los Angeles County, we investigated possible associations between single-nucleotide polymorphisms in the XRCC1 (codons 194 Arg/Trp and codon 399 Arg/Gln) and XRCC3 (codon 241 Thr/Met) genes and colorectal adenoma risk and their possible role as modifiers of the effect of monounsaturated fatty acid, the ratio of omega-6/omega-3 polyunsaturated fatty acids, and antioxidant intake. We found no evidence of associations between the XRCC1 codon 194 Arg/Trp or Trp/Trp genotypes and the XRCC3 codon 241 Thr/Met or Met/Met genotypes. Subjects with the XRCC1 Gln/Gln genotype were inversely associated with adenoma risk (odds ratio, 0.6; 95% confidence interval, 0.4-0.9; P = 0.01) when compared with subjects with Arg/Arg and Arg/Gln genotypes combined. We found no evidence of gene-dietary fat interactions for the XRCC3 codon 241 polymorphism. However, our data suggest an XRCC1-unsaturated fat interaction. High monounsaturated fatty acid intake was associated with adenoma risk only among subjects with the XRCC1 codon 194 Arg/Arg and codon 399 Gln/Gln combined genotypes (P for interaction = 0.018). High omega-6/omega-3 polyunsaturated fatty acid ratios were associated with adenoma risk among subjects with the XRCC1 codon 194 Arg/Arg and codon 399 Gln/Gln or the codon 194 Arg/Trp or Trp/Trp and codon 399 Arg/Arg or Arg/Gln combined genotypes (P for interaction = 0.026). These interactions were not modified by antioxidant intake. However, low antioxidant intake was associated with an inverse association only among subjects with the XRCC1 codon 194 Arg/Trp or Trp/Trp and codon 399 Arg/Arg or Arg/Gln combined genotypes (P for interaction = 0.022), which was independent of unsaturated fat intake. Our data suggest that the XRCC1 codon 194 and codon 399 single nucleotide polymorphisms may modify the effect of unsaturated fatty acid and antioxidant intake and that this XRCC1 effect modification may explain, in part, previously reported inconsistencies on the role of unsaturated fatty acids and adenoma risk.     

Polymorphisms in DNA repair gene XRCC1 and increased genetic susceptibility to glioma

Background: The XRCC1 gene encodes the XRCC1 protein, which complexes with three other DNA repair enzymes involved in the base-excision repair (BER) pathways. Different XRCC1 polymorphisms may increase the risk of cancers by impairing interaction with other enzymatic proteins and consequently altering DNA repair activity, and result in carcinogenesis. Our study aimed to investigate any association between three polymorphisms of the XRCC1 gene at codon 194, 280 and 399 and potential glioma risk. Methods: We collected 127 patients with primary glioma and 249 controls who requested general health examinations from Union Hospital of Tongji Medical College hospital from March 2007 to September 2010. A total of 5 ml venous blood was drawn from each subject. The polymorphisms of XRCC1 gene at codons 194, 280 and 399 were analyzed based on duplex polymerase-chain-reactions with the confronting-two-pair primer (PCR-CTPP) method. Results: The homozygous Trp/Trp and heterozygotes Arg/Trp variants of codon 194 had a 2.12 fold and 1.46 fold increased risk of glioma compared to the homozygous Arg/Arg wide genotypes. The same effect was found in codon 399, the codon 399 Gln/Gln and Arg/Gln genotypes being associated with a 2.24 fold and 1.67 fold increased risk in glioma. When comparing the codon 194 Arg/Arg and 399 Arg/Arg genotypes, the combination of codon 194 Trp allele and 399 Gln allele had a heavy increase in glioma risk (OR=2.87, 95%CI=1.56-6.73). Conclusion: The present study provided evidence of a potential role for XRCC1 codon 194 and 399 polymorphisms in genetic predisposition to glioma among the Chinese population. This analysis of correlation of DNA repair genes and glioma may provide a deeper insight into the genetic and environment factors for cancer risk.     

XRCC1 Polymorphisms are Associated with Cervical Cancer Risk and Response to Chemotherapy: a Systematic Review and Meta-analysis

Background: Functional single nucleotide polymorphisms of x-ray repair cross-complementing protein1 (XRCC1) have been suspected to contribute to uterine cervical cancer risk for a long time; however, mostprevious case-control studies were small sized and biased. Additionally, recent studies suggested that XRCC1polymorphisms could be a biomarker of response to platinum-based chemotherapy. Methods: A comprehensivesearch was conducted to retrieve eligible studies and odds ratios (ORs) and 95% confidence intervals (95% CIs)were calculated to measure association strength. Results: A total of 13 studies were identified and analyzed. Wefound that the Arg194Trp polymorphism (Trp vs. Arg, OR=1.342, 95% CI: 1.176) was associated with increasedrisk of cervical cancer, while no significant association was found with Arg280His (His vs. Arg, OR=1.059, 95%CI: 0.863, 1.299) or Arg399Gln (Gln vs. Arg, OR=1.144, 95% CI: 0.938, 1.394). As for response to platinumbasedchemotherapy, the variant XRCC1 399Gln allele (Gln vs. Arg, OR=0.345, 95% CI: 0.163, 0.729) waslinked with a poor response; however, the Arg194Trp polymorphism (TrpArg vs. ArgArg, OR=6.421, 95% CI:1.573, 26.205) predicted a good response. Conclusion: The Arg194Trp polymorphism of XRCC1 increases riskof cervical cancer; the variant 399Gln allele predicts poor response to platinum-based chemotherapy, while theArg194Trp polymorphism indicates a good response.     

Predictive Value of Xrcc1 Gene Polymorphisms for Side Effects in Patients undergoing Whole Breast Radiotherapy: a Metaanalysis

Radiation-induced side effects on normal tissue are determined largely by the capacity of cells to repairradiation-induced DNA damage. X-ray repair cross-complementing group 1 (XRCC1) plays an important role inthe repair of DNA single-strand breaks. Studies have shown conflicting results regarding the association betweenXRCC1 gene polymorphisms (Arg399Gln, Arg194Trp, -77T>C and Arg280His) and radiation-induced side effectsin patients undergoing whole breast radiotherapy. Therefore, we conducted a meta-analysis to determine thepredictive value of XRCC1 gene polymorphisms in this regard. Analysis of the 11 eligible studies comprising2,199 cases showed that carriers of the XRCC1 399 Gln allele had a higher risk of radiation-induced toxicity thanthose with the 399 ArgArg genotype in studies based on high-quality genotyping methods [Gln vs. ArgArg: OR,1.85; 95% CI, 1.20-2.86] or in studies with mixed treatment regimens of radiotherapy alone and in combinationwith chemotherapy [Gln vs. ArgArg: OR, 1.60; 95% CI, 1.09-2.23]. The XRCC1 Arg399Gln variant allele wasassociated with mixed acute and late adverse reactions when studies on late toxicity only were excluded [Gln allelevs. Arg allele: OR, 1.22; 95% CI, 1.00-1.49]. In contrast, the XRCC1 Arg280His variant allele was protectiveagainst radiation-induced toxicity in studies including patients treated by radiotherapy alone [His allele vs.Arg allele: OR, 0.58; 95% CI, 0.35-0.96]. Our results suggest that XRCC1 399Gln and XRCC1 280Arg may beindependent predictors of radiation-induced toxicity in post-surgical breast cancer patients, and the selectionof genotyping method is an important factor in determining risk factors. No evidence for any predictive valueof XRCC1 Arg194Trp and XRCC1 -77T>C was found. So, larger and well-designed studies might be requiredto further evaluate the predictive value of XRCC1 gene variation on radiation-induced side effects in patientsundergoing whole breast radiotherapy.     

XRCC1单核苷酸多态与晚期非小细胞肺癌对铂类药物化疗敏感性的相关性

背景与目的DNA修复能力与肿瘤细胞对铂类药物的敏感性密切相关。本研究探讨DNA修复基因XRCC1单核苷酸多态性与非小细胞肺癌(non-smallcelllungcancer,NSCLC)患者对顺铂(cisplatin,DDP)或卡铂(carboplatin,CBP)为主的化疗方案敏感性的关系。方法经病理学确诊的晚期NSCLC患者105例,采用DDP或CBP为主的方案化疗,2～3个周期后进行临床疗效评价。以PCR-RFLP进行XRCC1Arg194Trp和Arg399Gln多态的基因分型,比较不同基因型对化疗敏感性的影响。比值比(OR)及其95%可信区间(CI)由logistic回归模型计算。结果携带至少一个Trp等位基因者化疗有效率为43.1%,显著高于携带Arg/Arg基因型的20.3%(OR=2.97,95%CI=1.15～7.72;P<0.05)。携带XRCC1399Arg/Arg基因型者化疗有效率为41.5%,显著高于携带至少一个Gln等位基因者的21.2%(OR=2.65,95%CI=1.03～6.87;P<0.05)。这两个多态之间存在联合作用,同时携带194Arg/Trp和399Arg/Arg基因型的患者,治疗有效率为66.7%,明显高于携带其它基因型的患者(有效率20.0%～23.1%)。结论XRCC1基因多态与NSCLC患者对铂类药物化疗的敏感性相关。