An inhibitory effect of tumour promoters on human epithelial cell growth can be dissociated from an effect on junctional communication.
Studies with rodent cells have indicated that the abilities of various tumour promoters to inhibit metabolic cooperation correlate with their potencies as mitogens. Here we have examined the effects of the most potent phorbol ester tumour promoter 12-O-tetradecanoyl phorbol-13-acetate (TPA), on metabolic cooperation and growth of human epidermal cells transformed by SV40 (SVK14 cells). In this system, TPA inhibits junctional communication and at the same concentration also inhibits growth in a reversible fashion. These effects appear to be mediated by binding of phorbol ester to a single class of high affinity binding site with a Kd similar to that reported for rodent cells (Kd = 20.9 nM at 4 degrees C). Further studies on the effects of phorbol esters on other human epithelial cell lines reveal that the inhibitory effects of TPA on growth and metabolic cooperation may be completely dissociated. Alternative mechanisms by which TPA may exert its growth-inhibitory effects are discussed.
D001943:Breast Neoplasms / Q000473:pathology; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D002450:Cell Communication / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002472:Cell Transformation, Viral; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism; D006801:Humans; D015240:Phorbol 12,13-Dibutyrate; D010703:Phorbol Esters / Q000378:metabolism / Q000494:pharmacology*; D010704:Phorbols / Q000494:pharmacology*; D011493:Protein Kinase C; D011956:Receptors, Cell Surface / Q000378:metabolism; D011955:Receptors, Drug; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D010703:Phorbol Esters; D010704:Phorbols; D011956:Receptors, Cell Surface; D011955:Receptors, Drug; C083141:phorbol ester binding protein; C027776:phorbol ester receptor; D015240:Phorbol 12,13-Dibutyrate; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate