The involvement of p38 mitogen-activated protein kinase in the alpha-melanocyte stimulating hormone (alpha-MSH)-induced melanogenic and anti-proliferative effects in B16 murine melanoma cells

Activation of p38 or p44/42 mitogen-activated protein (MAP) kinases has bee n shown to trigger differentiation in a number of cell types. The present s tudy has investigated the roles of these kinases in the alpha-melanocyte st imulating hormone (alpha-MSH)-induced melanogenic and proliferative respons es in B16 melanoma cells. Treatment of cells with alpha-MSH led to the time -dependent phosphorylation of both p38 and p44/42 MAP kinases, However, onl y inhibition of p38 MAP kinase activity with SB 203580 blocked both the alp ha-MSH-induced melanogenic and anti-proliferative effects. It therefore app ears that activation of the p38 pathway can promote melanogenesis and inhib it growth of B16 melanoma cells. (C) 2000 Federation of European Biochemica l Societies. Published by Elsevier Science B.V. All rights reserved.