P53 codon 72 gene polymorphism studies and p53 expression by IHC in oral lesions as risk factor for malignancy

Abstract

Background Genetic mutation of p53 gene is common in several head and neck cancers, usually associated with smoking and HPV infection. In India, instead of HPV, tobacco/Pan Masala chewing are more commonly associated with oral cancer. Accordingly, the present study was planned. Materials and method A total 41 cases of oral lesions which comprise 6 cases of leukoplakia and 35 cases of oral SCC were studied. The patients were between 30 and 60 years age and were tobacco/Pan Masala chewers. Analysis of p53 codon 72 gene polymorphisms was performed by PCR RFLP for Arg/Arg, Arg/Pro and Pro/Pro. Tissue expression of p53 was done by IHC. Results Genotype frequencies of 35 carcinoma cases of p53 Arg/ Arg, Arg/Pro and Pro/Pro were 22.86%, 57.15% and 20%, respectively, and 6 leukoplakia cases of p53 Arg/Arg, and Arg/ Pro genotype were 50% and 50%. Out of 21 oral SCC biopsies, 14 (66.66%) showed p53 protein staining, 3 (14.28%) had weak staining and 4 (19.04%) showed negative staining. Among 6 cases of leukoplakia, 3 (50%) showed weak staining and 3 (50%) showed negative staining. Conclusion The findings indicate that Arg/Pro polymorphism of p53 codon 72 gene and p53 IHC expression might be associated with oral SCC/ leukoplakia.