XPD基因与胃癌易感性的相关性

背景与目的：DNA修复系统的变异与肿瘤发生密切相关。本研究拟探讨XPD多态性及单倍型与胃癌易感性的关联。方法：提取华北地区207例胃癌患者及212例健康献血者外周血基因组DNA，用扩增阻滞突变系统-聚合酶链反应（amplification refractory mutation system-polymerase chain reaction．ARMS-PCR）和聚合酶链反应-限制性片段长度多态性法（polymerase chain reaction-restriction fragment length polymorphism，PCR-RFLP）检测codon3 12和codon 751位点的基因型。结果：codon 312基因型GA、AA病例组分布频率显著高于对照组（P〈0．01．OR=3．41，95％CI：2．06～4．79；P〈0．01，OR=3．47，95％CI：1．39 ～8．68）。codon751多态性在两组间分布差异无统计学意义（P〉0．05）。在单倍型AA（codon 312A-codon 751A）的分析中，病例组中杂合型（-／AA）及纯合型（AA／AA）的分布频率均较对照组明显增高（P〈0．01，OR=2．81，95％CI：1．82～4．34；P=0．02，OR=3．92，95％CI：1．31～11．70）。但其他三种单倍型在两组间的分布差异无统计学意义（P〉0．05）。结论：XPD基因codon312位点多态性与胃癌易感性明显相关．而单倍型AA（eodon 312A-codon 751A）也是胃癌发生的易感因素。

Correlation of XPD gene with susceptibility to gastric cancer

Background and Objective： Mutations in DNA repair system are related to carcinogenesis. This study was to evaluate the correlations of polymorphisms and haplotypes of XPD gene with individual susceptibility to gastric cancer. Methods： Genomic DNA were extracted from peripheral blood leukocytes of 207 gastric cancer patients and 212 healthy controls. Genotypes at codon 312 and codon 751 polymorphic sites were identified by amplification refractory mutation system-polymerase chain reaction （ARMS-PCR） or polymerase chain reaction-restriction fragment length polymorphism （PCR- PFLP）, respectively. Results： At codon 312, the frequency of GA or AA genotype was higher in the gastric cancer patients than in the healthy controls （P〈0.01, OR=3.41, 95% Cl： 2.06-4.79; P〈0.01, OR=3.47, 95% CI：1.39- 8.68）. No significant difference was found in the distribution of the polymorphism at codon 751 between the two groups （P〉0.05）. By the haplotype AA （codon 312A-codon 751A） analysis, the frequency of heterozygote （-/AA） or homozygote （AA/AA） was higher in the patients than in the controls （P〈0.01, OR=2.81, 95% Cl： 1.82-4.34; P=0.02, OR=3.92, 95% Cl：1.31-11.70, respectively）. Whereas there were no significant differences of the other three haplotypes between the patients and the controls （P〉0.05）. Conclusions： The polymorphism of XPD at codon 312 might contribute to the etiology of gastric cancer. The haplotype AA （codon 312A-codon 751A） would be a critical risk factor of the susceptibility to gastric cancer.