Novel association of oral squamous cell carcinoma with GSTP1 Arg187Trp gene polymorphism

Glutathione S-transferase subtype pi 1 (GSTP1) is an enzyme that is involved in the detoxification of carcinogenic substances. Arg187Trp is a functional polymorphism in the corresponding GSTP1 gene that reduces the enzymatic activity by 45%. We evaluated, for the first time, the association of Arg187Trp with the risk of oral squamous cell carcinoma and compared it with other established GSTP1 polymorphisms viz, Ile105Val and Ala114Val.

We carried out a 1:2 case-control study by recruiting 100 patients with oral squamous cell carcinoma and 200 age and gender-matched healthy individuals. Ile105Val, Ala114Val, and Arg187Trp polymorphisms were genotyped by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and their distribution in the study groups was compared by chi-squared test (Fisher's exact).

The minor allele of Ala114Val and Arg187Trp were more common in patients than in controls. In contrast, the distribution of Ile105Val minor allele was similar in the two groups. The differential distribution was also significant at the level of genotypes.

These results indicate that GSTP1 Arg187Trp is associated with the risk of developing oral squamous cell carcinoma. Our study underlines the importance of detoxification pathway in the risk of carcinogenesis.