bFGF is the putative natural growth factor for human melanocytes

Normal human melanocytes, unlike pigment cells from metastatic melanomas, do not survive in culture in routine, serum-supplemented media. The search for natural growth factors for melanocytes has shown that mitogenic activity is ubiquitous in several tissues and in melanomas. Of several known growth factors tested, basic fibroblast growth factor (bFGF) was the only one mitogenic for melanocytes but only in the presence of cyclic-adenosine-monophosphate (cAMP) stimulators. The mitogenic activity toward melanocytes in tissues and melanoma cell extracts had high affinity for heparin and antibodies to bFGF synthetic peptides. These results suggest that one of the growth factors for melanocytes might be bFGF or a bFGF-like polypeptide and that autocrine production of bFGF-like molecules by melanoma cells may contribute to the malignant phenotype of melanocytes. Because acidic FGF (aFGF) did not stimulate growth, the receptors for bFGF on melanocytes might be significantly different from those for a FGF.