Genetic polymorphisms of glutathione S-transferase Mu 1, glutathione S-transferase theta 1, and glutathione S-transferase P1 in oral squamous cell carcinoma: A case-control study in Iranian population

Background: Gene variability related to activation and detoxification of procarcinogens affects the susceptibility to oral squamous cell carcinoma (OSCC). The results of numerous studies investigating the interrelationship between polymorphisms of glutathione S- transferase enzymes are not conclusive and there are little data regarding this topic on Iranian population. Aims and Objectives: This study aimed to investigate the genetic polymorphisms in glutathione S-transferase Mu 1 (GSTM1), glutathione S-transferase theta 1 (GSTT1), and glutathione S-transferase P1 (GSTP1) and the association with the risk of OSCC in Iranian population. Materials and Methods: The genetic polymorphisms of GSTM1, GSTT1, and GSTP1 genes were investigated in 35 Iranian patients with the OSCC and 60 age-sex matched controls. GSTP1 genotyping was performed by polymerase chain reaction (PCR)-restriction fragment length polymorphism method and GSTM1 and GSTT1 genotyping was amplified with PCR using specific primers. Odds ratios (ORs) and their 95% confidence intervals (CIs) were obtained using SPSS 17 and the risk of OSCC in relation to GSTM1, GSTT1, and GSTP1 polymorphism was defined. Results: The prevalence of GSTM1 and GSTT1 null genotypes in OSCC group were significantly higher than the control group.(OR = 2.6, 95% CI = 1.04-6.5; P = 0.01 for GSTM1) (OR = 11, 95% CI = 9-31; P = 0.001 for GSTT1). The GSTP1 valine polymorphism was not significantly different between the study groups (P = 0.145). Conclusions: GSTM1 and GSTT1 null genotypes may increase the risk for OSCC development in Iranian patients