RESUMO
Squamous cell carcinoma is the most common malignant neoplasm of the oral cavity. Number of mechanisms plays a role at the molecular level to transform normal cell into a neoplastic cell. There are a gamut of genes, which are expressed among which bcl-2, have gained a unique importance as inhibitor of apoptosis. In normal epithelial cells Bcl-2 is restricted to stem cells and cells which undergo mitosis. Bcl-2 blocks the post-mitotic phase from apoptosis. Reports of Bcl-2 protein expression in carcinomas are conflicting such as down regulation to elevated expression. In the present study 67 cases of squamous cell carcinomas of varying grades were studied and uniform cytoplasmic positivity were noted in 12 cases for Bcl-2 protein. Bcl-2 prolongs cell survival in epithelial cells and there by giving way to other external stimulus like action of carcinogens and viral agents and interaction with other genes and aids in progression to neoplasia. The possible roles of bcl-2 in the pathogenesis of oral squamous cell carcinoma are discussed.