title: TNF-alpha promotes Doxorubicin-induced cell apoptosis and anti-cancer effect through downregulation of p21 in p53-deficient tumor cells.
abstract: p53 is a key regulator in cell apoptosis, and cancer cells deficient in p53 expression fail to respond to chemotherapy. Here we show that effective Doxorubicin (DOX)-induced apoptosis is p53-dependent. However, an alternative treatment of DOX/TNF-alpha/DOX restored sensitivity of p53-deficient cells to DOX-induced apoptosis. Treatment of cells with TNF-alpha resulted in a decrease of p21 (waf1/cip1/sdi1) expression following second dose of DOX. In previous work, we demonstrated that p21 suppressed DOX-induced apoptosis via its (cyclin-dependent kinase) CDK-binding and CDK-inhibitory activity. Thus, we propose that TNF-alpha enhances the anti-cancer effect of DOX through suppressing the anti-apoptotic activity of p21, and that a combined treatment TNF-alpha/Dox is an effective chemotherapeutic strategy for p53-deficient cancers.
authors.affiliation: Laboratory of Medical Molecular Virology, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Cao
authors.forename: Wan-Hao
authors.initials: WH
authors.lastname: Chi
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Juan-Juan
authors.initials: JJ
authors.lastname: Tang
authors.forename: Yan-Jun
authors.initials: YJ
authors.lastname: Lu
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D042846:CDC2-CDC28 Kinases / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D045744:Cell Line, Tumor; D051357:Cyclin-Dependent Kinase 2; D050759:Cyclin-Dependent Kinase Inhibitor p21; D015536:Down-Regulation; D004317:Doxorubicin / Q000494:pharmacology*; D019008:Drug Resistance, Neoplasm; D004357:Drug Synergism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000970:Antineoplastic Agents; C493956:CDKN1A protein, human; D018797:Cell Cycle Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016328:NF-kappa B; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; D016159:Tumor Suppressor Protein p53; D004317:Doxorubicin; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2