谷胱甘肽转硫酶M1、T1基因型及烟酒嗜好与胃癌易感性的关系

[目的]探讨谷胱甘肽转硫酶基因多态性M1（GSTM1）、T1（GSTT1）及烟酒嗜好与胃癌易感性的关系，并对GST基因多态性GSTT1、GSTM1与烟酒暴露在胃癌发生中的交互作用进行分析。[方法]采用1：1配对病例-对照研究方法和PCR技术，检测121例原发性胃癌患者和相应对照的GSTM1和GSTT1基因型，结合研究对象的烟酒嗜好，应用SAS统计分析系统，分析GSTM1和GSTT1基因型及烟酒暴露与胃癌发病的关系，并对基因-基因，基因-烟酒暴露在胃癌发生中的交互作用进行分析。[结果]GSTM1（-）基因型频率在病例组和对照组中分别占44．63％和33．88%，分布无显著性差异（χ^2=2．6436，P〉0．05），GSTT1（-）基因型频率在病例组和对照组中分别为52．89％和44．63名，分布也无显著性差异（χ^2=1．1650，P〉0．05）。吸烟者比非吸烟者发生胃癌的危险高（OR=2．538，95％CI：1．336～4．823）；饮酒者比非饮酒者发生胃癌的危险高（OR=2．097，95％CI：1．025～4．291）。同时携带GSTM1（-）和GSTT1（-）基因型者发生胃癌的危险性高于GSTM1（＋）和GSTT1（＋）基因型携带者（OR=2．097，95％CI：1．025～4．291）；同时有烟酒嗜好的个体发生胃癌的危险性高于无烟酒嗜好者（OR=2．330，95％CI：1．211～4．482）。携带GSTM1（-）和GSTT1（-）且有烟酒嗜好者，发生胃癌的危险显著高于携带GSTM1（＋）和GSTT1（＋）的无烟酒嗜好者（OR=3．600，95％CI：1．025～12．650）。[结论]吸烟、饮酒与胃癌易感性增加有关，GSTM1和GSTT1基因型及烟酒嗜好在胃癌发生中存在一定的交互作用。

Influence GSTM1 and GSTT1 Genotypes and Smoking, Alcohol Exposure on the Occurrence of Gastric Cancer: Case-control Study from Nanjing,China

[Objective] To determine the association between glutathione-s-transferase genetic polymorphisms(GSTM1,GSTT1) and smoking, alcohol exposure with the risk of gastric cancer and elucidate the action and interaction of gene and environmental factors. [ Methods ] 1:1 Case-control study was conducted and polymerase chain reaction technique was employed to analyse the genetic polymorphisms of GST (GSTM1 ,GSTT1) genotype in 121 cases of patients with gastric cancer and sex, age-matched controls, who were selected from Nanjing Zhongda hospital and Jiangsu Province Cancer Hospital. Conditional logistic analysis was performed to elucidate the genetic and environmental risk (smoking and drinking) for gastric cancer. [ Results ] GSTM1 null genotype was more commonly observed in cases, but this was not statistically significant. The frequency of GSTM1 null genotype in cases and controls was 44.63% and 33.88%, respectively (x2=2.6436, P > 0.05); that of GSTT1 was 52.89% and 44.63% respectively (x2=1.1650, P > 0.05). Cigarette smoking and alcohol exposure were significantly associated with gastric cancer respectively, and the Odd Ratios(OR) were 2.538 (95%CI: 1.336-4.823) and 1.928 ( 95%CI: 1.011-3.667 ) respectively. An interaction was observed between GSTMl, GSTT1 genetic types and smoking, alcohol drinking to gastric cancer: People who carry GSTM1(-), GSTT1(-) were prone to development of gastric cancer; OR=2.097 (95%CI: 1.025-4.291); people co-abused smoking and alcohol had a higher susceptibility to gastric cancer than those non-smoking and non-alcohol drinking, OR=2.330 (95%CI: 1.211-4.482); People who carry GSTM1(-), GSTT1(-) and exposed to smoking and alcohol had a higher susceptibility to gastric cancer than those with GSTM1(+), GSTT1(+) and non-smoking and non-alcohol drinking, (OR=3.600, 95%CI: 1.025-12.650). [ Conclusion ] Smoking and drinking habit are likely associated with the susceptibility to gastric cancer; interaction of GSTM1, GSTT1 genotype and smoking, alcohol drinking exists in the risk of gastric cancer.