结直肠癌患者的DNA修复基因XRCC1单核苷酸多态研究

目的 探讨DNA碱基切除修复基因XRCC1单核苷酸多态与结直肠癌易感性的关系.方法 采用病例-对照分子流行病学方法,以聚合酶链反应-限制性酶切片段多态性(PCRRFLP)方法分析120例结直肠癌患者和150例正常对照XRCC1基因单核苷酸多态Arg194Trp和Arg399Gln的基因型分布,并比较不同基因型与结直肠癌风险的关系.结果 正常人群中194Arg/Arg、Arg/Trp和Trp/Trp基因型频率分别为52.0%、42.0%和6.0%,而结直肠癌患者中分别为40.8%、46.7%和12.5%,分布差异有统计学意义(P＜0.05,趋势检验).与携带野生基因型Arg/Arg者比较,携带Trp/Trp基因型个体患结直肠癌的风险降低了1. 43倍(校正OR=2.43;95%CI=1.10～5.92).而194Arg/Trp基因型和Arg399Gln遗传多态则与结直肠癌风险无关.结论 DNA修复基因XRCC1 Arg194Trp多态可能是结直肠癌发生的遗传易感因素.

Polymorphisms of DNA repair gene XRCC1 and genetic susceptibility to colorectal cancer

Objective To assesse the relationship between XRCC1 polymorphisms, Argl94Trp and Arg399Gln, and susceptibility to colorectal cancer (CRC). Methods Genotypes were determined by PCR-RFLP methods in 150 healthy controls and 120 patients with colorectal cancer. The adjusted odds, ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression. Results The distribution of XRCC1 Argl94Trp genotypes among controls was Arg/Arg (53.0% ), Arg/Trp (42.0% ) , and Trp/Trp (6.0% ) , while the frequencies of the 3 genotypes among colorectal cancer cases were 40.8% , 46.7% and 12.5%, respectively (P<0.05, trend test). Individuals carrying Trp/Trp genotype were at an increased risk for colorectal cancer compared with those with the Arg/Arg (adjusted OR, 2.43; 95% CI = 1.10-5.92). However, Arg399Gln polymorphism was not found to be associated with risk of CRC. Conclusion The XRCC1 Argl94Trp polymorphism may be associated with the risk of CRC in this Chinese population.