Effect of alpha tocopheryl succinate on cyclic AMP-dependent protein kinase activity in murine B-16 melanoma cells in culture.

d-Alpha tocopheryl succinate (vitamin E succinate), which inhibited growth and survival, and induced differentiation in murine B-16 melanoma cells in culture, increased adenosine 3',5'cyclic monophosphate-(cAMP)-dependent protein kinase (PK) activity without increasing the cellular cAMP level. Prostaglandin (PG)A2, which produced changes in melanoma cells similar to those produced by vitamin E succinate, also increased cAMP-dependent PK activity without changing the intracellular level of cAMP.