胃癌亚甲基四氢叶酸还原酶基因677CT多态性与幽门螺杆菌感染的关系

目的　探讨重庆地区胃癌人群亚甲基四氢叶酸还原酶 (MTHFR)基因 6 77CT多态性及其与幽门螺杆菌 (H .pylori)感染的关系。方法　采用聚合酶链反应和限制性片段长度多态性技术(PCR RFLP) ,检测 6 6例胃癌和 10 1例正常人组织的 6 77CT多态性 ,采用PCR和Warthin Starry银染色检测幽门螺杆菌。结果　MTHFR基因 6 77CT多态性可分为 3种基因型 ,即 6 77CC、6 77CT和 6 77TT。胃癌组 3种基因型频率分别为 4 5 5 %、4 0 9%和 13 6 %。等位基因频率 6 77C为 6 9 8% ,6 77T为 30 2 %。对照组中 6 77CC、6 77CT和 6 77TT频率分别为 4 8 5 %、4 2 6 %和 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统计学差异。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 )。3种基因型胃癌中H .pylori的检出率无统计学差异 (P>0 0 5 )。结论　重庆地区人群中 ,MTHFR基因 6 77CT多态性是胃贲门癌的保护因素 ,是胃体癌的危险因素 ;胃癌MTHFR基因 6 77CT多态性与H .pylori感染无关

THE RELATIONSHIP BETWEEN METHYLENETETRAHYDROFOLATE REDUCTASE GENE POLYMORPHISM AND HELICOBACTER PYLORI INFECTION IN GASTRIC CANCER

Objective The relationship between methylene tetrahydrofolate reductase (MTHFR) C677T polymorphism and H.pylori infection was explored in gastric cancer. Methods MTHFR gene polymorphism was detected by polymerase chain reaction restriction fragment length polymorphism (PCR RFLP) and H.pylori was identified with PCR and Warthin Starry methods. Results MTHFR 677CT polymorphism was analyzed in 66 patients of gastric cancer and 110 normal controls. The genotype frequencies of MTHFR 677CC,677CT and 677TT were 45 5%,40 9% and 13 6% in patients with gastric cancer, and 48 5%,42 6% and 8 9% in controls. There was no significant difference between patients with gastric cancer and controls ( P >0 05). The individuals with 677CT and 677CT TT genotypes 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 with 677CC genotype. The individuals with 677TT genotype had a 3 63 fold (95%CI,1 04 12 72) increased risk of developing gastric corpus cancer. MTHFR 677CT polymorphism was not correlated with H.pylori infection in gastric cancer. Conclusion The polymorphism of MTHFR 677CT is associated with increased risk of gastric corpus cancer and reduced risk of gastric cardia cancer, but not with H.pylori infection