亚甲基四氢叶酸还原酶基因多态性与胃癌关系的研究

The relationship between methylenetetrahydrofolate reductase gene polymorphism and risk of gastric cancer

目的 探讨重庆地区人群亚甲基四氢叶酸还原酶基因多态性与胃癌的关系。方法 采用聚合酶链反应和限制性片段长度多态性技术 ,检测 6 6例胃癌和 10 1例正常对照的MTHFR基因C6 77T多态性。结果 MTHFRC6 77T呈多态性 ,可分为3种类型 :6 77CC、6 77CT、6 77TT。胃癌组 3种基因型频率分别为 :6 77CC 4 5 .5 %、6 77CT 4 0 .9%、6 77TT 13.6 % ,等位基因频率6 77C为 6 5 .9% ,6 77T为 34.1%。对照组中 6 77基因频率分别为 :6 77CC 4 8.5 %、6 77CT 4 2 .6 %、6 77TT 8.9% ,等位基因频率6 77C为 6 8.8% ,6 77T为 31.2 % ,胃癌组与对照组相比无显著差异。以 6 77CC基因型作为参考 ,胃贲门癌 6 77CT基因型OR为0 .2 1,95 %CI(0 .0 3～ 0 .99) ,6 77CT +TT基因型OR为 0 .2 6 ,95 %CI(0 .0 7～ 0 .98) ;胃体癌 6 77TT基因型OR为 3.6 3,95 %CI(1.0 2～ 12 .72 )。结论 重庆地区人群中 ,亚甲基四氢叶酸还原酶基因C6 77T多态性是胃贲门癌的保护因素 。

Objective To explore the relationship between methylenetetrahydrofolate reductase (MTHFR) polymorphism and risk of gastric cancer among population in Chongqing region.Methods MTHFR gene polymorphism of C677T were detected in 66 patients with gastric cancer and 101 control subjects by polymerase chain reaction restriction fragment length polymorphism (PCR RFLP).Results The genotype frequency of MTHFR 677CC was 48.5% among the controls and was 45.5% among the patients with gastric cancer; the genotype frequency of MTHFR 677CT was 42.6% among the controls and 40.9% among the patients with gastric cancer. The frequency of 677TT was 8.9% among the controls and 13.6% among patients with gastric cancer.The individuals with 677CT genotype and 677CT+TT genotype group had a 0.21 fold [95% confidence interval(CI),0.43～0.99] and 0.26 fold (95%CI,0.07～0.98) reduced risk of developing gastric cardia cancer compared with those had 677CC genotype. The individuals with 677TT genotype had 3.63 fold (95%CI,1.04～12.72) increased risk of developing gastric corpus cancer.Conclusion The polymorphism of MTHFR C677T was associated with increased risk for gastric corpus cancer,and was associated with reduced risk for gastric cardia cancer.