title: Inhibition of X-ray and doxorubicin-induced apoptosis by butyrolactone I, a CDK-specific inhibitor, in human tumor cells.
abstract: Cell-cycle progression is coordinately regulated by cyclin-dependent kinases (CDKs). The inhibition of CDKs by p21Waf1/Cip1/Sdi1 prevents the apoptosis of cells treated with DNA-damaging agents. In this study, we found that butyrolactone I, a specific inhibitor of CDC2 family kinases, blocks the X-ray- or doxorubicin-induced apoptosis of DLD1 (p21+/+) human colorectal carcinoma cells in a dose-dependent manner. We also found that butyrolactone I inhibits the CDK2 activity and enhances cell survival after an X-ray irradiation or doxorubicin treatment in both DLD1 (p21-/-) and DLD1 (p21+/+) cells. These findings suggest that butyrolactone I prevents apoptosis by the direct inhibition of CDK and also, possibly, by CDK-inhibition through p53-independent p21-induction. Our findings indicate that CDK activity is required for DNA-damaging agent-induced apoptosis.
authors.affiliation: Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshida-konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Lu
authors.forename: H
authors.initials: H
authors.lastname: Takebe
authors.forename: T
authors.initials: T
authors.lastname: Yagi
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects*; D002453:Cell Cycle / Q000187:drug effects / Q000528:radiation effects; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000037:antagonists & inhibitors*; D004317:Doxorubicin / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D014965:X-Rays
chemical_list: D000903:Antibiotics, Antineoplastic; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D004791:Enzyme Inhibitors; D004317:Doxorubicin; C082868:butyrolactone I; D015107:4-Butyrolactone