亚甲基四氢叶酸还原酶基因型、饮食习惯与胃癌的易感性

目的：研究亚甲基四氢叶酸还原酶（MTHFR）基因C677T多态性、饮食习惯与胃癌易感性的关系。方法：在上消化道癌高发区淮安市楚州区进行了一个病例－对照研究（胃癌107例，人群对照200例），调查研究对象的生活习惯，用PCR－RFLP技术检测研究对象的MTHFR基因型。结果：（1）胃癌组中MTHFR C／T或T／T型基因携带者占79．4％，显著高于对照组的68．5％（χ^2=4.15,P=0.0416,OR=1.78,95% CI:0.99-3.22;调整OR＝1．79，95％CI：1．01－3．19）。（2）在不经常吃大蒜、大葱者中，MTHFR C／T或T／T型基因携带者发生胃癌的危险性显著升高。在不饮茶者中或在经常吃肉者中，携带MTHFRC／T或T／T型基因者发生胃癌的危险性也显著上升。结论：MTHFR C677T基因型与胃癌的易感性有关；不同饮食习惯对MTHFR C677T基因型与胃癌易感性之间的关系有影响。

Methylenetetrahydrofolate reductase genotypes, dietary habits and susceptibility of stomach cancer

Objective The relation between methylenetetrahydrofolate reductase (MTHFR) C677T genotypes?dietary habits and the risk of stomach cancer (SC) was studied. Methods A case-control study was conducted with 107 cases of SC and 200 population-based controls in Chuzhou district, Huaian, Jiangsu province, China. The epidemiological data were collected, and DNA of peripheral blood leukocytes was obtained from all of the subjects. MTHFR genotypes were detected by PCR-RFLP. Results (1) The prevalence of the MTHFR C /T or T /T genotypes was found to be significantly different between controls (68.5%) and SC cases (79.4%, P = 0.0416 ), the increased risk had an adjusted OR of 1.79 (95% CI: 1.01-3.19). (2) Among subjects who had low intake of garlic or Chinese onion, MTHFR C /T or T /T genotypes significantly increased the risk of developing SC. Among non tea-drinkers or among subjects who had frequent intake of meat, the carriers of the MTHFR C /T or T /T genotypes had a higher risk of SC than individuals with C /C type MTHFR . Conclusion The polymorphism of MTHFR C677T was associated with risk of developing SC, and that individuals with different genotypes may have different susceptibilities to SC, based on environmental factors.