The GSTP1 Ile105Val Polymorphism is not Associated with Susceptibility to Colorectal Cancer

The glutathione S transferase (GST) family is a major part of cellular defense mechanisms against endogenousand exogenous substances, many of which have carcinogenic potential. Alteration in the expression level orstructure of the glutathione-S-transferase (GST) enzymes may lead to inadequate detoxification of potentialcarcinogens and consequently contribute to cancer development. A member of the glutathione-S-transferase (GST)family, GSTP1, is an attractive candidate for involvement in susceptibility to carcinogen-associated colorectalcancer. An AgG transition in exon 5 resulting in an Ile105Val amino acid substitution has been identified whichalters catalytic efficiency. The present study investigated the possible impact of Ile105Val GSTP1 polymorphism onsusceptibility to colorectal cancer. in Jordan We examined 90 tissue samples previously diagnosed with colorectalcarcinoma, and 56 non-cancerous colon tissues. DNA was extracted from paraffin embedded tissues and thestatus of the GSTP1 polymorphism was determined using a polymerase chain reaction restriction fragmentlength polymorphism (RFLP) method. No statistically significant differences were found between colorectalcancer cases and controls for the GSTP1 Ile/Ile, Ile/Val and Val/Val genotypes. The glutathione S-transferasepolymorphism was not associated with risk in colorectal cancer cases in Jordan stratified by age, sex, site, gradeor tumor stage. In conclusion, the GSTP1 Ile105Val polymorphism is unlikely to affect the risk of colorectalcancer.