Abstract
Treatment with the tumor-promoting phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) and the second-stage promoter 12-O-retinoylphorbol 13-acetate induced down-regulation of protein kinase C (PKC) and enhanced the migration of C3H 10T1/2 cells. In the case of BT5C glioma cells the same negative correlation was observed only after treatment with TPA. The negative control 4 alpha-phorbol affected neither PKC activity nor the migratory ability of both cell lines.