Melanogenesis, biosynthetic phenotype of fibronectin and collagen, and migrating activity in cloned B16 mouse melanoma cells.

Three clones, melanotic (M3), amelanotic (A4 and A7) cells were isolated from B16 F10 mouse melanoma cell line. These clones exhibited different biosynthetic activities of fibronectin and collagen: A4 clone showed relatively active synthesis of both collagen and fibronectin, and A7 clone exhibited most active fibronectin synthesis, whereas no significant synthesis of these molecules was observed in M3 clone. No significant difference in growth rate was observed in these three clones. Migrating activities measured by basement membrane matrix-coated dishes were greater in A7 clone than in A4 and M3 clones. Messenger RNA levels of collagen and fibronectin paralleled collagen and fibronectin synthesis in these clones whereas tyrosinase mRNA level was unaltered between melanotic (M3) and amelanotic (A4 and A7) cells. These results indicate that B16 melanoma cells have heterogeneous cell populations consisting of different biosynthetic and metastatic properties. These clones may provide good tools for studying the relationship between the phenotypes of melanogenesis biosynthesis of extracellular macromolecules and migrating activity of melanoma cells.