Human papillomavirus (HPV) infects the squamous epithelial cells of oral cavity and cervix leading to formation of warts that develops into the cancer. Human papillomavirus (HPV)-16 and 18 encode E6 oncoprotein, which binds to and induces degradation of the tumour suppressor protein p53. A common polymorphism of p53, encoding either proline (Pro) or arginine (Arg) at position 72, affects the susceptibility of p53 to E6 mediated degradation in vivo. Oral cancer is a pressing problem in India due to the widespread habit of chewing betel quid, which plays an important role in etiology of this disease. In the present study an attempt has been made to analyze the genetic predisposition of the Indian population to HPV infection and oral carcinogenesis. In our study a total of 110 cases of Oral Cancer highly addicted to betel quid and tobacco chewing are analyzed for HPV 16/18 infection and its association with polymorphism at p53 codon 72. Of these a total number of 37 patients (33.6%) have shown the presence of HPV, among which the presence of HPV-16, 18 and 16/18 coinfection is 22.7%, 14.5% and 10%, respectively. Our results also indicate that the p53 codon 72 genotype frequencies in Indian Oral Cancer patients are 0.55 (Arg) and 0.45 (Pro) as per Hardy-Weinberg equilibrium. In our study, striking reduction in Pro/Pro allele frequency has been found in HPV positive cases, indicating Arg/Arg genotype to be more susceptible to HPV infection and oral carcinogenesis.
Copyright 2001 Wiley-Liss, Inc.