Relationship between genetic polymorphism of glutathione S-transferase-p1 and p53 protein accumulation in Iranian esophageal squamous cell carcinoma patients

Background: It has been reported that the activity of glutathione S-transferase (GST) is over-expressed in plasma and esophagus biopsies in Iranian patients suffering from esophageal squamous cell carcinoma (SCC). The aim of this study was to find out the frequency of GST-P genotypes in these patients. Moreover, the association of GST-P genotypes with p53 protein accumulation in esophageal epithelium was investigated.
Materials and Methods: DNA isolated from paraffin-embedded tissue biopsies from patients suffering from esophageal SCC (n = 56) were collected. polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using Alw261 enzyme was applied to determine GST-P genotypes (Ile 105 Val). All the samples were also subjected to immunohistochemistry (IHC) for p53.
Results: The frequency of GST-P genotypes in Iranian esophagus SCC patients for Ile/Ile, Ile/Val and Val/Val was 73.2, 21.5 and 5.3%. There was no association between GST-P polymorphism and p53 accumulation in esophageal epithelial cells.
Conclusions: The frequency of GST-P polymorphism was not associated with p53 protein accumulation in esophagus epithelium. The frequency of polymorphic variants of GST-P, Ile/Ile, Ile/Val and Val/Val in SCC patients may suggest that Ile to Val substitution in GST-P gene dose not represent susceptibility to SCC in high-risk Iranian population.

Keywords
Esophageal squamous cell carcinoma, glutathione S-transferase, Iran, p53, polymorphism