Polymorphisms in glutathione S-transferases in French vinyl chloride workers.

The authors have recently demonstrated a significant gene-environment interaction between vinyl chloride exposure and polymorphisms in the DNA repair protein XRCC1 on the occurrence of mutant p53 biomarkers of vinyl chloride-induced genetic damage. The aim of this study was to examine the polymorphisms in the glutathione S-transferases (GSTs) as potential modifiers of this relationship, since these enzymes may be involved in the phase II metabolism of the reactive intermediates of vinyl chloride. A cohort of 211 French vinyl chloride workers was genotyped for common polymorphisms in GSTM1, GSTT1 and GSTP1. Although no independent, statistically significant effect of these polymorphisms on the occurrence of the mutant p53 biomarker was found, the null GSTM1 and null GSTT1 polymorphisms were found to interact with the XRCC 1 polymorphism to increase the occurrence of the biomarker such that, for example, workers with at least one variant XRCC1 allele who were null for both GSTM1 and GSTT1 had a significant odds ratio for the biomarker (OR =8.4, 95% CI = 1.3 54.0) compared with workers who were wild-type for all alleles, controlling for potential confounders including cumulative vinyl chloride exposure.