Deregulation of cyclin-dependent kinase 2 activity correlates with UVC-induced apoptosis in Chinese hamster ovary cells

✍ Scribed by Chu-Bin Liao; Yu-Ching Chang; Chien-Wen Kao; Ezhilan Sathyapriya Taniga; Hsun Li; Bor-Show Tzang; Yin-Chang Liu

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 564 KB
• Volume: 97
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.20688

✦ Synopsis

Abstract

Progression through the cell cycle relies on the activities of cyclin‐dependent kinases (Cdk), which in turn are modulated by inhibitory proteins such as p21^(waf1/cip1)^ that are induced when genomic damage occurs. In this study, we show that exposure of normal mammalian cells, such as NIH3T3 fibroblasts, to UVC (25 J/m^2^, at 254 nm) induces the expression of p21 without causing significant apoptosis, whereas similar treatment of Chinese hamster ovary (CHO‐K1) cells with UVC causes apoptosis without inducing p21. The absence of p21 in UV‐irradiated CHO‐K1 cells is accompanied by the deregulation of Cdk2 activity. The elevation of Cdk2 activity correlates with the increase of UV‐induced apoptosis, which can be suppressed by small‐molecule Cdk2 inhibitors such as roscovitine and pyrrolidine dithiocarbamate. The results of this study suggest that the deregulation of Cdk2 activity may be critical to UV‐induced apoptosis in CHO‐K1 cells. J. Cell. Biochem. 97: 824–835, 2006. © 2005 Wiley‐Liss, Inc.