[Differentiation and tumorigenicity of human malignant melanocytes. Comparative study of two "non pigmented" and pigmented lines from the same fibroblastoid cells].

A morphological, caryological and biochemical study of two established cell lines of human malignant melanocytes derived from the same original tumour, when compared with heterotransplantation results in nude Mice, showed that "non-pigmented" cells are more tumorigenic than pigmented cells. Differentiation and tumorigenicity, although concomitant, here seem to be two independent phenomena.