人端粒保护蛋白1基因单核苷酸多态性与胃癌的关系

Relationship between single-nucleotide polymorphisms of human protection of telomeres 1 genes and gastric cancer

目的探讨人端粒保护蛋白1基因（hPOT1）IVS13—98G／T位点单核苷酸多态性与胃癌的关系。方法收集2005年12月至2006年7月甘肃省武威肿瘤医院、武威市人民医院、武威市凉州区医院168例胃癌患者（胃癌组）和156例健康受试者（对照组）的血液标本，采用聚合酶链反应和限制性片段长度多态性技术行基因型分析，比较各基因型分布频率与胃癌发病风险的关系。采用矿检验比较胃癌组和对照组hPOT1IVS13—98G／T位点的基因型分布和等位基因频率，用Hardy—weinberg平衡检验基因型和等位基因频率分布是否具有群体代表性。相对危险度和95％CI以非条件Logistic回归模型计算。结果胃癌组hPOT1IVS13—98G／T位点GG、GT、TT型的频率分别为21．4％、41．7％、36．9％，G、T等位基因的频率分别为42．3％、57．7％；对照组GG、GT、TT型的频率分别为24．4％、51．9％、23．7％，G、T等位基因频率分别为49．7％和50．3％。两组G、T等位基因型频率比较差异无统计学意义（χ2=3．58，P〉0．05）。以TT型作为参照基因型，GT和GG两种基因型相对危险度分别为0．439（95％CI：0．251—0．767，P〈0．05）、0．514（95％凹：0．264—0．999，P=0．05）。hPOT1IVS13—98G／T位点各基因型与性别、吸烟及肿瘤家族史对胃癌发病没有影响。结论hPOT1IVS13—98G／T位点的GT和GG型可能与胃癌的易感性降低有关，hPOT1IVS13—98G／T位点单核苷酸多态性可能为胃癌的保护因素。

Objective To investigate the relationship between single-nucleotide polymorphisms of IVS13- 98G/T of human protection of telomeres 1 （hPOT1） genes and gastric cancer. Methods A total of 168 patients with gastric cancer （gastric cancer group） who had been admitted to Wuwei Cancer Hospital, Wuwei People＇s Hospital and Liangzhou District Hospital from December 2005 to July 2006 and 156 healthy people （control group） were genotyped by polymerase chain reaction （PCR） and PCR-restriction fragment length polymorphism （PCR- RFLP） method, and the relationship between the distribution of genotypes and the risk factors of gastric cancer was analyzed. The distribution of genotypes and allele frequency between the 2 groups were compared by chi-square test. Hardy-weinberg equilibrium test was adopted to determine whether the distribution of genotypes and allele frequency were representative. Relative risk and 95% confidence interval were calculated by non-conditional Logistic regression model. Results The frequencies of genotypes GG, GT and TT of hPOTlIVS13-98 G/T were 21.4%, 41.7% and 36.9% in gastric cancer group, and 24.4% , 51.9% and 23.7% in control group. The allele frequencies of G- and T-allele were 42.3% , 57.7% in gastric cancer group, and 49.7% , 50. 3% in control group. There was no significant difference in allele frequencies of G- and T-allele between the 2 groups （χ2 = 3.58, P 〉 0.05 ）. Compared with genotype TIC, the relative risks for GT and GG were 0. 439 （95% CI： 0. 251-0. 767, P 〈 0.05 ） and 0.514 （ 95% CI： 0. 264-0. 999, P = 0.05 ）. There was no influence of different genotypes of hPOT1IVS13-98 G/T, sex, smoking history, family history of cancer on gastric cancer. Conclusion Single-nucleotide polymorphisms of IVS13-98G/T of hPOT1 may be a protective factor of gastric cancer.