Modulation of protein kinase C activity during inhibition of tumor cell growth by IFN-beta and -gamma.
We investigated the effects of human interferon(IFN)-beta and -gamma on protein kinase C activity in human HEp-2 and KHm-14 tumor cells during IFN-induced inhibition of cell growth. Cytosolic protein kinase C activity in both cell lines was strikingly decreased following treatment with either IFN-beta or -gamma. In the particulate fraction, IFN-gamma decreased protein kinase C activity within 1 hr but it reappeared after 24 hr, whereas IFN-beta decreased the activity during the inhibition of cell growth. Furthermore, phorbol-12,13-dibutyrate(PDBu)-binding activity was altered in parallel with the changes in protein kinase C activity induced by the IFNs. In summary, we showed that IFN-beta and -gamma cause long-term modulation of protein kinase C activity in these cultured tumor cells.
D002455:Cell Division; D003600:Cytosol / Q000201:enzymology; D006801:Humans; D007370:Interferon Type I / Q000494:pharmacology*; D007371:Interferon-gamma / Q000494:pharmacology*; D007700:Kinetics; D008545:Melanoma / Q000201:enzymology / Q000473:pathology; D010610:Pharyngeal Neoplasms / Q000201:enzymology / Q000473:pathology; D015240:Phorbol 12,13-Dibutyrate; D010703:Phorbol Esters / Q000378:metabolism; D011493:Protein Kinase C / Q000037:antagonists & inhibitors* / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000201:enzymology* / Q000473:pathology
D007370:Interferon Type I; D010703:Phorbol Esters; D015240:Phorbol 12,13-Dibutyrate; D007371:Interferon-gamma; D011493:Protein Kinase C