title: Involvement of cyclin-dependent kinases in doxorubicin-induced apoptosis in human tumor cells.
abstract: Apoptotic cell death caused by doxorubicin, a chemotherapeutic agent, is suppressed by expression of p21 (waf1/cip1/sdi1), a cyclin-dependent kinase (cdk) inhibitor. To examine cdk activity required for doxorubicin-induced apoptosis, we transfected p21-deficient human tumor DLD1(p21-/-) cells with plasmids carrying wild-type p21 and mutated p21 unable to bind to cdks or proliferating cell nuclear antigen. The apoptosis induced at the G(2)/M phase after doxorubicin treatment was suppressed by transient expression of the p21 with cdk-binding activity but not by the p21 lacking the activity. We also transfected cells with plasmids carrying wild-type, dominant negative and constitutively active mutants of cdk2 or cdk4. The apoptosis was suppressed by transient expression of dominant negative mutants of cdk2 or cdk4. These findings indicate that cdk is involved in the doxorubicin-induced apoptosis pathway.
authors.affiliation: Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Lu
authors.forename: M
authors.initials: M
authors.lastname: Tatsuka
authors.forename: H
authors.initials: H
authors.lastname: Takebe
authors.forename: T
authors.initials: T
authors.lastname: Yagi
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002453:Cell Cycle / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000473:pathology; D050759:Cyclin-Dependent Kinase Inhibitor p21; D018844:Cyclin-Dependent Kinases / Q000378:metabolism*; D016213:Cyclins / Q000235:genetics / Q000378:metabolism; D004317:Doxorubicin / Q000494:pharmacology*; D006801:Humans; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D011485:Protein Binding; D014407:Tumor Cells, Cultured
chemical_list: D000903:Antibiotics, Antineoplastic; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D018809:Proliferating Cell Nuclear Antigen; D004317:Doxorubicin; D018844:Cyclin-Dependent Kinases