title: Mechanisms underlying the pro-survival pathway of p53 in suppressing mitotic death induced by adriamycin.
abstract: The p53 tumor suppressor responds to chemotherapeutic stress by triggering apoptosis or eliciting pro-survival pathway through arresting cell cycle progression for DNA damage repair. Here we examined the pro-survival activity of p53 on the adriamycin-induced stress using H1299 cells stably expressing tsp53 V143A, a temperature-sensitive mutant activating only the subset of p53 target genes related to growth arrest and DNA repair, but not apoptosis. At 38 degrees C, cells evaded from adriamycin-induced G2 arrest and died of apoptosis and mitotic catastrophe, which could be inhibited by Cdk inhibitors. Activation of functional tsp53 V143A at 32 degrees C led to suppression of Cdk1/2 activities and Cyclin B1/Cdk1 expression, cells exhibited prolonged G2 arrest, regained reproductive potential and were protected from mitotic catastrophe induced by adriamycin. Inhibition of mitotic catastrophe and Cyclin B1/Cdk1 expression was ablated upon silencing p21 Waf1 expression in tsp53 V143A-H1299 cells or in HCT116 cells. Together we show that p21 Waf1 is a key component of G2 checkpoint necessary and sufficient for protecting tumor cells against adriamycin-induced mitotic catastrophe.
authors.affiliation: Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan 11221.
authors.forename: Yi-Cheng
authors.initials: YC
authors.lastname: Lin
authors.forename: Fung-Fang
authors.initials: FF
authors.lastname: Wang
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D016203:CDC2 Protein Kinase / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects*; D019926:Cyclin B / Q000378:metabolism; D051357:Cyclin-Dependent Kinase 2 / Q000378:metabolism; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D004317:Doxorubicin / Q000494:pharmacology*; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology; D008938:Mitosis / Q000187:drug effects* / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology; D016159:Tumor Suppressor Protein p53 / Q000187:drug effects / Q000378:metabolism*
chemical_list: D000903:Antibiotics, Antineoplastic; C493956:CDKN1A protein, human; D019926:Cyclin B; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016159:Tumor Suppressor Protein p53; D004317:Doxorubicin; D016203:CDC2 Protein Kinase; D051357:Cyclin-Dependent Kinase 2