[Cell differentiation in human melanoma cells caused by dicarbamine (ultrastructural investigation)]

The effects of dicarbamine (r) and polytransretinoic acid (PTRA) on human melanoma MEL-6 transplanted into Balb/c nude female mice have been compared by histological and electron microscopic procedures. It was discovered that long-term administration of 1.5 mg/kg dicarbamine caused melanoma MEL-6 cells to undergo terminal differentiation. As a result, the number of melanosome-containing cells was 3-4 times and the number of melanosomes in them--5 times those in intact controls. Dicarbamine effect was double that of PTRA.