Polymorphism of the glutathione S-transferase P1 gene (GST-pi) in breast carcinoma

Breast carcinoma is the most common cancer and cause of death among females worldwide, including Jordan. The risk factors for breast carcinoma are linked to DNA mutation and failure of DNA repair or detoxification systems. Identification of susceptibility factors that predispose individuals to breast carcinoma if they are exposed to particular environmental agents might give further insight into the etiology of this malignancy. The glutathione S-transferase (GST) enzyme family detoxifies carcinogenic compounds. Several genes that code for these enzymes are polymorphic, with particular genotypes previously shown to confer an increased carcinoma risk. The present study investigates GST-pi polymorphism in 100-tissue samples previously diagnosed as breast carcinoma, and in 48 non-cancer age-matched breast tissues, using the restriction fragment length polymorphism (RFLP) method for the polymerase chain reaction (PCR) product. Among breast cancer cases, 58%, 40% and 2% were homozygous (Ile/Ile), heterozygous (Ile/Val) and homozygous (Val/Val) respectively. In the control group, 58%, 37.5% and 4.2% were homozygous (Ile/Ile), heterozygous (Ile/Val), and homozygous (Val/Val) respectively. Our results did not support the involvement of GST-pi gene polymorphism in susceptibility to breast carcinoma in the tested North Jordanian female population.