Saadat Mostafa
Department of Biology, College of Sciences, Shiraz University, Shiraz 71454, Iran.
Cancer Sci. 2006 Jun;97(6):505-9. doi: 10.1111/j.1349-7006.2006.00207.x.
The association between glutathione S-transferase T1 (GSTT1) polymorphism and gastric cancer risk has been both confirmed and refuted in a number of published studies. Most of these studies were based on small sample sizes. We carried out a meta-analysis of the research published up to August 2005 to obtain more precise estimates of gastric cancer risk associated with GSTT1 polymorphism. In the present study, 16 case-control studies (with a total of 6717 subjects) were eligible for meta-analysis. There was no evidence of heterogeneity between the studies. The GSTT1 null genotype conferred a 1.06-fold increased risk of gastric cancer, which was not significant (95% confidence interval [CI]: 0.94-1.19). However, in the analysis of ethnic groups, we observed distinct differences associated with GSTT1 status. Restricting analyses to ethnic groups, the pooled odd ratios for the GSTT1 genotype were 1.27 in Caucasians (95% CI: 1.03-1.57) and 0.98 in Asians (95% CI: 0.86-1.13). Glutathione S-transferase M1 (GSTM1) and GSTT1 are involved in detoxification of a variety of compounds, some that overlap between enzymes and some that are highly specific. To investigate whether the profile of glutathione S-transferase genotypes was associated with risk of gastric cancer, further analyses combining the GSTT1 and GSTM1 genotypes were also carried out. There was a significant trend in risk associated with zero, one and two putative high-risk genotypes (chi2 = 9.326, d.f. = 1, P = 0.0023). Those who had null genotypes of GSTM1 and GSTT1 had an increased gastric cancer risk compared with those who had both active genes (odds ratio = 2.08, 95% CI: 1.42-3.10).
谷胱甘肽S-转移酶T1（GSTT1）基因多态性与胃癌风险之间的关联在一些已发表的研究中既有得到证实的，也有被否定的。这些研究大多基于小样本量。我们对截至2005年8月发表的研究进行了荟萃分析，以更精确地估计与GSTT1基因多态性相关的胃癌风险。在本研究中，16项病例对照研究（共6717名受试者）符合荟萃分析的条件。各研究之间没有异质性的证据。GSTT1无效基因型使胃癌风险增加了1.06倍，但无统计学意义（95%置信区间[CI]：0.94 - 1.19）。然而，在种族分析中，我们观察到与GSTT1状态相关的明显差异。将分析限制在种族群体中，GSTT1基因型的合并比值比在白种人中为1.27（95% CI：1.03 - 1.57），在亚洲人中为0.98（95% CI：0.86 - 1.13）。谷胱甘肽S-转移酶M1（GSTM1）和GSTT1参与多种化合物的解毒过程，其中一些在酶之间存在重叠，一些则具有高度特异性。为了研究谷胱甘肽S-转移酶基因型谱是否与胃癌风险相关，还进行了结合GSTT1和GSTM1基因型的进一步分析。与零个、一个和两个假定的高风险基因型相关的风险存在显著趋势（χ2 = 9.326，自由度 = 1，P = 0.0023）。与同时拥有两个活性基因的人相比，GSTM1和GSTT1无效基因型的人患胃癌的风险增加（比值比 = 2.08，95% CI：1.42 - 3.10）。
