Genetic polymorphism of glutathione S-transferase P1 gene and lung cancer risk

Objectives: The human GSTTP1 gene is polymorphic with an A --> G transition in exon 5 causing a replacement 105 Ile --> Val in the GSTP1 protein. The two isoforms, encoded by the alleles GSTP1*A and GSTP1*B, respectively, sho w different catalytic efficiencies towards some carcinogenic epoxides. In t his study we have addressed the possible role of the Ile105Val GSTP1 polymo rphism in lung cancer susceptibility. Methods: The polymorphic site was genotyped by RFLP in a group of lung canc er patients (n = 164) and in two control groups (healthy smokers, n = 132; general population, n = 200). All patients and controls were Northwestern M editerranean Caucasians of the same ethnic origin. Results and Conclusions: The cancer patients showed frequencies of GSTP1*A/ A; GSTP1*A/B and GSTP1*B/B (50%, 38%, 11%, respectively) very similar to th ose of both control groups (healthy smokers: 48%, 41%, 11%). After adjustin g for age, sex and smoking status, no association was found between the GST P1*B allele and lung cancer risk (OR: 1.18; 95% CI: 0.67-2.07). The Ile105v al GSTP1 polymorphism was also analysed in combination with the GSTM1 and G STT1 genes. The results showed that allelism at GSTP1 did not increase the risk associated with the GSTM1 or GSTT1 deletions.