title: DNA damage induces a novel p53-survivin signaling pathway regulating cell cycle and apoptosis in acute lymphoblastic leukemia cells.
abstract: Survivin is a novel member of the inhibitor of apoptosis protein (IAP) family. Here we report that the chemotherapeutic drug doxorubicin, a DNA-damaging agent, activates a p53-survivin signaling pathway inducing cell cycle arrest and apoptosis in childhood acute lymphoblastic leukemia (ALL). Treatment of wild-type (wt) p53 ALL cells (EU-3 cell line) with doxorubicin caused accumulation of p53, resulting in dramatic down-regulation of survivin, depletion of cells in G(2)/M, and apoptosis (increased sub-G(1) compartment). In contrast, doxorubicin treatment of mutant (mut) p53 cells (EU-6/ALL line) up-regulated survivin and induced G(2)/M arrest without inducing apoptosis. However, treating EU-6 with anti-survivin antisense resensitized these cells to doxorubicin, resulting in apoptosis. With a p53-null cell line (EU-4), although doxorubicin treatment arrested cells in G(2)/M, survivin expression was unchanged, and cells underwent only limited apoptosis. However, re-expression of wt-p53 in EU-4 cells could restore the doxorubicin-p53-survivin pathway, resulting in significantly decreased survivin expression and increased apoptosis in these cells after doxorubicin treatment. Following cotransfection of p53-null EU-4 cells with survivin promoter-luciferase constructs and either wt-p53 or different mut-p53 expression vectors, wt-p53 inhibited survivin promoter activity; p53-mediated inhibition could be abrogated by overexpression of murine double minute2 (MDM2) protein. Together, these studies define a novel p53-survivin signaling pathway activated by DNA damage that results in down-regulation of survivin, cell cycle arrest, and apoptosis. Furthermore, our data indicate that loss of wt-p53 function in tumor cells may contribute to up-regulation of survivin and resistance to DNA-damaging agents.
authors.affiliation: Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia 30322, USA. mzhou@emory.edu
authors.forename: Muxiang
authors.initials: M
authors.lastname: Zhou
authors.forename: Lubing
authors.initials: L
authors.lastname: Gu
authors.forename: Fengzhi
authors.initials: F
authors.lastname: Li
authors.forename: Yerun
authors.initials: Y
authors.lastname: Zhu
authors.forename: William G
authors.initials: WG
authors.lastname: Woods
authors.forename: Harry W
authors.initials: HW
authors.lastname: Findley
mesh_terms: D017209:Apoptosis / Q000502:physiology*; D002453:Cell Cycle / Q000502:physiology*; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics* / Q000502:physiology; D015853:Cysteine Proteinase Inhibitors / Q000502:physiology; D004249:DNA Damage; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008156:Luciferases / Q000235:genetics; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D000077022:Survivin; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000235:genetics* / Q000502:physiology
chemical_list: C107489:BIRC5 protein, human; D002868:Chromosomal Proteins, Non-Histone; D015853:Cysteine Proteinase Inhibitors; D051034:Inhibitor of Apoptosis Proteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D011994:Recombinant Proteins; D000077022:Survivin; D016159:Tumor Suppressor Protein p53; D008156:Luciferases