p53 and bak Mutations in Oral Cancers Associated with Betel Quid Chewing in India.

Abstract

Betel quid chewing is very common in India and other Southeast Asian countries, and it is an important risk factor in oral carcinogenesis. To know the underlying mechanism and the response to radiotherapy, we have analyzed 50 primary oral squamous cell carcinomas for mutations in the p53 gene (exons 4-8) and bak gene (exons 3,4,6) by PCR-Cold SSCP and direct sequencing. The incidence of p53 mutation was 58% (29 of 50), while it was only 0-10% in betel quid-unrelated oral cancer. Most mutations(86%) were transition mutations. Furthermore, mutations were found predominantly in codon 250 and codon 286 (15%, and 13%, respectively), and 35% of the amino acid changes were Pro to Ser. Mutations were also found in the bak gene, and poor prognosis was observed in cancer patients with bak mutation, although there were no differences between p53 mutation (+) and (-) patients. [J Radiat Res 44:450-451 (2003)]