Promoter methylation and genetic polymorphism of glutathione S-transferase P1 gene (GSTP1) in Thai breast- cancer patients.

The GSTP1 gene encodes for a detoxification enzyme involved in protecting cells from carcinogens. In breast cancer, GSTP1 polymorphisms may produce lower effective enzyme detoxification properties and GSTP1 promoter hypermethylation may result in inactivation of GSTP1 expression. We therefore hypothesized an influence on progression of breast cancer.