title: Polymorphisms of DNA repair gene XRCC3 Thr241Met and risk of gastric cancer in a Chinese population.
abstract: Mammalian cells are constantly exposed to a wide variety of genotoxic agents from both endogenous and exogenous sources. Genetic variability in DNA repair may contribute to human cancer risk. In this population-based case-control study in China, we tested the hypothesis that a C to T variant (Thr241Met) of DNA repair gene XRCC3 (X-ray repair cross-complementing group 3) is associated with risk of developing gastric cancer. We genotyped for this variant using polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) in 188 histologically confirmed gastric cancer patients and 166 frequency-matched cancer-free controls. The XRCC3 genotype and allele frequencies were not significantly different between cases and controls (P = 0.99 for genotype; P = 0.76 for allele). The XRCC3 241Met allele frequency (4.8%) was significantly lower in healthy Chinese controls than previously reported healthy US Caucasian controls (38.9%). Compared with the XRCC3 241Thr/Thr genotype, the variant XRCC3241Thr/Met and Met/Met genotypes were not associated with an increased risk of gastric cancer (adjusted odds ratio (OR(a)), 1.06; 95% confidence interval (CI), 0.52-2.16). These findings suggest that polymorphisms of XRCC3 Thr241Met may not play a role in the etiology of gastric cancer. Further studies with a larger number of subjects and simultaneous measurement of different polymorphisms in DNA repair genes in the same pathway are needed to confirm these findings.
authors.affiliation: Department of Epidemiology and Statistics, School of Public Health, Nanjing Medical University, Nanjing 210029, China. hbshen@njmu.edu.cn
authors.forename: Hongbing
authors.initials: H
authors.lastname: Shen
authors.forename: Xinru
authors.initials: X
authors.lastname: Wang
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Hu
authors.forename: Zhengdong
authors.initials: Z
authors.lastname: Zhang
authors.forename: Yaochu
authors.initials: Y
authors.lastname: Xu
authors.forename: Xu
authors.initials: X
authors.lastname: Hu
authors.forename: Jiantao
authors.initials: J
authors.lastname: Guo
authors.forename: Qingyi
authors.initials: Q
authors.lastname: Wei
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000235:genetics; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D004260:DNA Repair / Q000235:genetics*; D004273:DNA, Neoplasm / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation / Q000235:genetics*; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000235:genetics*
chemical_list: D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; C110901:X-ray repair cross complementing protein 3