Stimulation of DNA synthesis in murine fibroblasts by the tumour promoter teleocidin: relationship to phorbol esters and vasopressin

The recently reported tumour promoter teleocidin is a potent mitogen for murine fibroblasts, at nM concentrations. Despite its unrelated structure, teleocidin inhibits binding of phorbol dibutyrate to Swiss 3T3 cells, and is inactive as a mitogen for cells in which the phorbol dibutyrate receptors have been down-regulated. Teleocidin shows synergistic stimulation of DNA synthesis with a wide range of purified growth factors, but fails to synergise with vasopressin, suggesting that it utilises the same mitogenic pathway as this physiological ligand.