title: Genetic polymorphisms of GSTO2, GSTM1, and GSTT1 and risk of gastric cancer.
abstract: OBJECTIVE
  The glutathione S-transferases (GSTs) are a superfamily of proteins that participates in detoxification. The GSTs were dividing into several classes including omega (GSTO), micro (GSTM) and theta (GSTT) classes. In human GSTO2, GSTM1, and GSTT1 are polymorphic. In order to study whether GSTO2, GSTM1, and GSTT1 polymorphisms are associated with increased gastric cancer risk in Iranian patients, the present case-control study was done.
  
  
  METHODS
  Genomic DNA was extracted from peripheral blood of 67 gastric cancer patients and 134 control subjects. The genotyping was performed using PCR-based method. The possible association of gastric cancer with the GSTO2 N142D polymorphism was estimated with assuming additive, dominant, and recessive effect of the variant 142D allele. To investigate whether profiles of GST genotypes are associated with the risk of gastric cancer, we used unconditional logistic regression analysis.
  
  
  RESULTS
  The GSTO2 142D allele in additive, dominant and recessive models was not associated with the risk. Because GSTM1, GSTT1, and GSTO2 genes belong to low-penetrance genes which might be involved in the carcinogenesis, patients and controls without family of cancer in first-degree relatives were also analyzes separately. To investigate whether profiles of GST genotypes are associated with the risk of gastric cancer, we used unconditional logistic regression analysis with GSTM1, GSTT1, and GSTO2 genotypes as predictor factors. The GSTO2 DD genotype was associated with decreased risk as compared to GSTO2 NN genotype (OR = 0.21, 95% CI: 0.05-0.92, P = 0.038).
  
  
  CONCLUSIONS
  Present findings show that GSTO2 DD genotype decreases the risk of gastric cancer in individuals without history of cancer in their first-degree relatives.
authors.affiliation: Department of Biology, College of Sciences, Shiraz University, Shiraz 71454, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Masoudi
authors.forename: Iraj
authors.initials: I
authors.lastname: Saadat
authors.forename: Shahpour
authors.initials: S
authors.lastname: Omidvari
authors.forename: Mostafa
authors.initials: M
authors.lastname: Saadat
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005982:Glutathione Transferase / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism
chemical_list: D005982:Glutathione Transferase; C413545:glutathione S-transferase T1; C492569:GSTO2 protein, human