Stimulation of choline transport in cultured cells induced by 12-O-tetradecanoylphorbol-13-acetate: one of the earliest phenomena induced by the tumor promoter.
12-O-tetradecanoylphorbol-13-acetate (TPA), a potent tumor promoter, stimulated membrane transport of choline in cultured cells. This is one of the earliest phenomena caused by tumor promoter. 4-O-methyl-TPA and mezerein showed similar stimulatory effects, but 4 beta-phorbol, which has no tumor-promoting activity, did not show any significant effect on choline transport. A calmodulin antagonist, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide, inhibited the TPA-stimulated transport of choline, whereas the protein kinase C inhibitor 1-(5-isoquinolinesulfonyl)-2-methylpiperazine did not. These results suggest that the Ca2+-calmodulin system, but not protein kinase C, may play an important role in the mechanism of this phenomenon.
Lijian
Y
Y
Department of Biochemistry, Kyoto Prefectural University of Medicine, Japan.
Nishino
H
H
Iwashima
A
A
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002147:Calmodulin / Q000378:metabolism; D002478:Cells, Cultured / Q000187:drug effects; D002794:Choline / Q000378:metabolism*; D004224:Diterpenes; D011493:Protein Kinase C / Q000378:metabolism; D013449:Sulfonamides / Q000494:pharmacology; D013729:Terpenes / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D002147:Calmodulin; D004224:Diterpenes; D013449:Sulfonamides; D013729:Terpenes; C049999:N-(6-phenylhexyl)-5-chloro-1-naphthalenesulfonamide; C011309:mezerein; D011493:Protein Kinase C; D002794:Choline; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium