Brief Communication: Differentiation of Melanocytes in Cultures of Primary Malignant Melanoma Indicated by 5-S-Cysteinyldopa Formation 2

Abstract

The dedifferentiation of cultured primary human malignant melanocytes was not accompanied by disappearance of 5-S-cysteinyldopa formation. The addition of conditioned medium from undifferentiated fibroblast-like cells brought about the reappearance of pigmented melanocytes and the increase of the metabolite in the cells and culture medium. The presence of 5-S-cysteinyldopa in cultured cells indicated the melanocytic origin of undifferentiated cells, and the increase of this metabolite was characteristic of differentiation.