Involvement of protein kinase C in the regulation of glycolipid sulfotransferase activity levels in renal cell carcinoma cells
Kobayashi, T.; Honke, K.; Gasa, S.; Sugiura, M.; Miyazaki, T.; Ishizuka, I.; Makita, A.
Cancer Research 53(11): 2484-2489
1993
ISSN/ISBN: 0008-5472 PMID: 8098660 Document Number: 422478
Accumulation of sulfolipids associated with elevated levels of glycolipid sulfotransferase activities has previously been demonstrated in renal cell carcinoma cells. To investigate the role of protein kinase C in the synthesis of sulfolipids, the effects of 12-O-tetradecanoylphorbol-13-acetate and protein kinase C inhibitors on glycolipid sulfotransferase activity levels were examined in a human renal cell carcinoma cell line, SMKT-R3. Continuous treatment of the cells with 12-O-tetradecanoylphorbol-13-acetate caused a dose- and time-dependent reduction of the sulfotransferase activity levels. Similarly, protein kinase C inhibitors, 1-(5-isoquinoline-sulfonyl)-2-methylpiperazine dihydrochloride and staurosporine, reduced the enzyme activities in a dose-dependent manner. These observations suggest that the glycolipid sulfotransferase activity levels are regulated by protein kinase C in SMKT-R3 cells. Furthermore, long-term 12-O-tetradecanoylphorbol-13-acetate treatment resulted in a reduction of sulfolipid synthesis and a decrease of the expression of sulfolipids on the cell surface. Taken together, it is suggested that protein kinase C is involved in the synthesis of sulfolipids through the regulation of the glycolipid sulfotransferase activity levels in renal cell carcinoma cells.