OVEREXPRESSION OF BCL-2 PROTEIN INHIBITS TERMINAL DIFFERENTIATION OF ORAL KERATINOCYTES IN-VITRO

The bcl-2 proto-oncogene is a known inhibitor of apoptosis; in normal human stratified squamous epithelium, its expression is restricted to the basal cell layer. To investigate the functional role of bcl-2 prot ein in the process of differentiation of oral keratinocytes, bcl-2 exp ression vector was transfected into SCC-25 cells, which normally under go squamous cell differentiation in vitro while expressing specific di fferentiation markers, e.g., keratin 10/11 and involucrin. In bcl-2 tr ansfected SCC-25 cells, the expression of these differentiation marker s was markedly suppressed. The bcl-2 proto-oncogene may play a critica l role in opposing the commitment to terminal differentiation and apop tosis of oral keratinocytes.