X线损伤交叉互补基因1多态性与结直肠癌易感性研究

The study on the relationship between XRCC1 gene polymorphisms and the susceptibility of colorectal cancer

目的探讨DNA修复酶X线损伤交叉互补基因1（XRCCl）外显子三个位点的基因多态性（Argl94Trp、Arg280His、Arg399Gln）与结直肠癌（CRC）发病风险的关系。方法以聚合酶链反应和限制性片段长度多态性（PCRRFLP）分析方法，采用病例一对照研究，对250例CRC患者（病例组，其中结肠癌128例，直肠癌122例）和213名健康人（对照组）的XRCCl基因三个位点的多态性进行了检测，采用SPSS11．0软件包统计分析各位点的基因型分布和等位基因频率。结果XRCCl基因194和399二个位点的各基因型频率在两组间分布差异均无统计学意义（P值均〉0．05），但病例组XRCCl基因280Arg／His基因型频率较对照组显著增高（校正后OR=1．66，95％CI：1．01～2．73，P=0．047）。在直肠癌患者组中，280Arg／His基因型频率较对照组显著增高（OR=1．82，95％CI：1．02～3．27），携等位基因280His（Arg280His＋His280His）的CRC患者的频率显著高于其在对照组中的频率（校正后OR1．85，95％CI：1．06～3．22），而在结肠癌患者中风险系数相对较低且差异无统计学意义（校正后OR=1．31，95％CI：0．74～2．35）。结论XRCClArgl94Trp和Arg399Gln基因多态性与结肠癌易感性无关，但280Arg／His基因型能增加CRC易感性，等位基因280His是直肠癌风险因素。

Objective To investigate the correlation between three gene locus polymorphisms of X-ray repair cross-complementary protein 1 （XRCC1） exon （Arg194Trp, Arg280His and Arg399Gln） and the risk of colorectal cancer （CRC）. Methods A case-control study was performed in 250 CRC patients （case group, 128 colon cancer patients and 122 rectal cancer patients） and 213 healthy individuals （control group）. The three gene locus polymorphism of XRCC1 was tested by polymerase chain reaction and restriction fragment length polymorphism （PCR-RFLP） method. The genotype distribution and allele frequency of each locus was analyzed with SPSS 10.0 software. Results There was no significant difference in allele frequency of XRCC1 at 194 and 399 loci （P 〉 0.05）. However, the 280 Arg/His allele frequency of XRCC1 was higher in case group than that in control group （OR= 1.66,95%CI：1.01-2.73,P=0.047）. The 280Arg/His allele frequency was higher in rectal cancer group than that in control group （OR =1.82,95%/0CI：1.02-3.27）. The frequency of 280His allele （Arg280His and His280His） was higher in case group than that in control group （OR--1.85,95%CI： 1.06-3.22）. However, it was a relative low risk factor of colon cancer and there was no significant difference between colon cancer group and control group （OR = 1.85, 95% CI： 1.06 - 3.22）. Conclusions There was no correlation between XRCC1 Arg194Trp and Arga99Gln polymorpohisms and the risk of CRC. However, 280Arg/His genotype may increase the risk of CRC, and 280His allele is a risk factor of rectal cancer.