Glutathione S-transferase polymorphisms and risk of bladder cancer in Thais

Abstract

In this study, we determine the association of glutathione S-transferase Mu-1 gene (GSTM1), glutathione S-transferase Pi-1 gene (GSTP1) and glutathione S-transferase Theta-1 gene (GSTT1) polymorphisms and the risk of bladder cancer in Thais. One hundred and thirty-nine bladder cancer patients and 278 control subjects were recruited for unmatch case control study. GSTM1 and GSTT1 were genotyped by multiplex PCR. Discrimination of GSTM1 heterozygote was determined by semi-quantitative Denaturing High Performance Liquid Chromatography (DHPLC) analysis. GSTP1 variants were identified by Polymerase Chain Reaction-Restriction Fragment Length Polymorphisms (PCR-RFLPs). Null alleles of GSTM1 and GSTT1 presented no association with the risk of bladder cancer. Individuals with heterozygous GSTP1 Ile/Val (isoleucine/valine) showed the protective effect to bladder cancer (odds ratio (OR) = 0.53 [0.33-0.84], p = 0.006). The combined analysis of GSTP1 wild type and GSTT1 heterozygous deletion (OR = 2.39 [1.24-4.59], p = 0.083) or homozygous deletion (OR = 2.44 [1.22-4.90], p = 0.011) demonstrated the increased risk of bladder cancer. In conclusion, risk of bladder cancer was affected by GST polymorphisms especially GSTP1 and the combination of GSTP1 and GSTT1.