Involvement of down-regulation-resistant protein kinase C in teleocidin inhibition of cell proliferation and calcium mobilization induced by epidermal growth factor and vasopressin in human hepatoma cells.

Abstract

Teleocidin, a phorbol ester-type tumor promoter, inhibits cell proliferation and calcium mobilization induced by epidermal growth factor and vasopressin in PLC/PRF/5 hepatoma cells. These inhibitory effects of teleocidin were observed even after a prolonged exposure of the hepatoma cells to this promoter, suggesting the presence of down-regulation-resistant protein kinase C in this hepatoma cell line. Column chromatography of cytosolic fractions showed three separate peaks of protein kinase C activity, two being down-regulation-sensitive while one was down-regulation-resistant. This down-regulation-resistant PKC is suggested to be responsible for the inhibitory effect of teleocidin on cell proliferation and calcium mobilization induced by epidermal growth factor and vasopressin.

• Authors: Y Kaneko, A Tsukamoto, K Kurokawa
• Journal: Cancer letters (Cancer Lett) Vol. 71 Issue 1-3 Pg. 103-8 (Jul 30 1993) ISSN: 0304-3835 [Print] Ireland
• PMID: 8395971 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Lyngbya Toxins
• Vasopressins
• teleocidins
• Epidermal Growth Factor
• Protein Kinase C
• Calcium

Topics

• Calcium (metabolism)
• Carcinoma, Hepatocellular
• Cell Count
• Cell Division (drug effects)
• Cell Line (drug effects)
• Down-Regulation (drug effects)
• Epidermal Growth Factor (antagonists & inhibitors)
• Humans
• Lyngbya Toxins (pharmacology)
• Protein Kinase C (antagonists & inhibitors, metabolism)
• Tumor Cells, Cultured (drug effects)
• Vasopressins (antagonists & inhibitors)