H‐ras Ribozyme‐Mediated, Alteration of the Human Melanoma Phenotype

The incidence of cutaneous melanoma worldwide has increased signdicantly in recent In the progressive stage of melanoma, its metastatic potential and its natural resistance to cancer chemotherapy present a challenging clinical problem in therapeutics? Several genes in the signal transduction pathway have been implicated as being involved in the development of mal ignan~y.~~ In fact, the overexpression of genes encoding growth factors, their receptors, and oncogenes have all k e n shown to be altered as melanocytes progress into mel-