Is there any association of glutathione S-transferase T1 (GSTT1) and glutathione S-transferase M1 (GSTM1) gene polymorphism with gastric cancers?

The glutathione S-transferases (GST) are enzymes catalyzing reactions including carcinogens. GSTT1 and GSTM1 genes are polymorphic in humans. The relations between polymorphism of some GST genes and cancer have been reported. In this study, we aimed to investigate the distribution of GSTT1 and GSTM1 polymorphisms in a group of gastric cancer patients. The study group consisted of 50 patients (21 females, 29 males) with gastric adenocarcinoma from the archives of the pathology department of a training hospital. Fifty-seven healthy control subjects were included in the study as a control group. DNA was extracted from peripheral venous blood of control subjects and from the paraffin blocks of cases. Genotyping of GSTT1 and GSTM1 genes was performed with duplex polymerase chain reaction. No differences in the frequencies of GSTM1 or GSTT1 null genotypes were observed between patients and healthy subjects (GSTM1: 52% vs. 43.85%, OR = 1.27, 95% CI: 0.55-2.96; GSTT1: 38.46% vs. 28.07%, OR = 0.72, 95% CI: 0.25-1.96). Moreover, simultaneous carriage of both genotypes was almost identical in both groups. GSTM1 or GSTT1 null genotypes were not different in diffuse or intestinal type gastric cancer. Our data suggest that the GSTM1 and GSTT1 polymorphisms are not associated with gastric cancer in a small group of the Turkish population.