Tuning up or down the UV-induced apoptosis in Chinese hamster ovary cells with cell cycle inhibitors.
Exposure to UVC induces apoptosis in Chinese hamster ovary (CHO.K1) cells. While studying the underlying mechanism, we found that a variety of cell cycle inhibitors, including colcemid, hydroxyurea and mimosine, enhance the UV-induced apoptosis in these cells. Such enhancement was not dependent on the cell cycle progression nor was it related to the difference in UV sensitivity at different phases of the cell cycle. The expression of p21(waf1/cip1), a general cyclin-dependent kinase (CDK) inhibitor, was deficient in CHO.K1 cells. Ectopic overexpression of the human p21 markedly increased the survival rates of the UV-irradiated cells in the presence of colcemid. In addition, roscovitine, a small-molecule inhibitor of CDK, also inhibited the UV-induced apoptosis. These observations suggest that deregulation of CDK activity may be critical in the UV-induced apoptosis in CHO.K1 cells.
Tzang
Bor-Show
BS
Department of Life Science, National Tsing-Hua University, Hsin-Chu, Taiwan.
Chiang
Yun-Jung
YJ
Lan
Hsin-Chieh
HC
Liao
Chu-Bin
CB
Liu
Yin-Chang
YC
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects*; D016466:CHO Cells; D002453:Cell Cycle / Q000187:drug effects*; D006224:Cricetinae; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000378:metabolism; D003703:Demecolcine / Q000494:pharmacology*; D004307:Dose-Response Relationship, Radiation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D014466:Ultraviolet Rays
D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D004791:Enzyme Inhibitors; D003703:Demecolcine