Okadaic acid Co-induces vimentin expression and cell cycle arrest in MPC-11 mouse plasmacytoma cells.
The effect of the tumor promoter okadaic acid on cell cycle progression and on vimentin expression in MPC-11 mouse plasmacytoma cells was compared with that of the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). Cell cycle progression of asynchronously grown MPC-11 cells was inhibited by both agents, but, in contrast to the G1 phase arrest caused by TPA, okadaic acid gave rise to G2/M phase and S phase arrest. This effect of okadaic acid was delayed significantly compared to the TPA-caused arrest. Furthermore, okadaic acid was able to induce vimentin expression to an extent comparable to the TPA response. However, vimentin expression was markedly delayed in okadaic acid-treated relative to TPA-treated cells. Another protein phosphatase inhibitor, calyculin A, also induced cell cycle changes and vimentin expression at concentrations at or above 1 x 10(-9) M. Based on these observations, we suggest an involvement of protein phosphatase 1 (possibly also phosphatase 2A and/or other phosphatases) in both the G2/M cell cycle block and the induction of vimentin expression in MPC-11 cells by okadaic acid.
Giese
G
G
Max-Planck-Institut für Zellbiologie, Ladenburg, Germany.
Wiegers
W
W
Kubbies
M
M
Scherbarth
A
A
Traub
P
P
D000818:Animals; D002273:Carcinogens / Q000494:pharmacology; D002453:Cell Cycle / Q000187:drug effects; D004988:Ethers, Cyclic / Q000494:pharmacology*; D005455:Fluorescent Antibody Technique; D051379:Mice; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D019319:Okadaic Acid; D010954:Plasmacytoma / Q000473:pathology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014746:Vimentin / Q000378:metabolism*
D002273:Carcinogens; D004988:Ethers, Cyclic; D014746:Vimentin; D019319:Okadaic Acid; D013755:Tetradecanoylphorbol Acetate