Factors regulating growth and pigmentation of melanoma cells.

Growth and melanization are intimately related in melanoma cells. MSH, by promoting elevated cyclic AMP levels, causes increases in melanization, cessation of growth, and gross morphologic changes in Cloudman S-91 melanoma cells. Growth inhibition results from high levels of cyclic AMP while growth stimulation occurs with lower levels. During melanization, oxidation products of tyrosine are generated which are toxic to the cells. Genetic studies have revealed that some of these processes are related through common biochemical pathways. This article reviews work of recent years on such regulatory mechanisms in melanoma.