Rapid activation and down-regulation of protein kinase C alpha in 12-O-Tetradecanoylphorbol-13-acetate-induced differentiation of human rhabdomyosarcoma cells

Abstrad Human rhabdomyosarcoma RD cells express the myogenic regulatory fadors MyoD and myogenin but differentiate spontaneously very poorly. Prolonged treatment of RD cells with the protein kinase C (PKC) adivator 12-O-tetradecanoylphorbol-1 3-acetate (TPA) induces growth arrest and myogenic differentiation as shown by the accumulation of a-adin and myosin light and heavy chains, without affeding the expression of MyoD and myogenin. In this study, we show that shortterm phorbol ester treatment of the cultures is sufficient to trigger myogenic differentiation but not growth