title: p53-induced apoptosis in the human T-ALL cell line CCRF-CEM.
abstract: The tumor suppressor p53 has been implicated in apoptosis induction and is mutated in human T-ALL CCRF-CEM cells. To investigate possible consequences of wild-type p53 loss, we reconstituted CEM-C7H2, a subclone of CCRF-CEM, with a temperature-sensitive p53 allele (p53ts). Stably transfected lines expressed high levels of p53ts and shift to the permissive temperature (32 degrees C) caused rapid induction of p53-regulated genes, such as p21(CIP1/WAF1), mdm-2 and bax. This was followed by extensive apoptosis within 24 h to 36 h, supporting the notion that mutational p53 inactivation contributed to the malignant phenotype. p53-dependent apoptosis was preceded by digestion of poly(ADP-ribose) polymerase, a typical target of interleukin-1beta-converting enzyme (ICE)-like proteases/caspases, and was markedly resistant to the ICE/caspase-1 and FLICE/caspase-8 inhibitor acetyl-Tyr-Val-Ala-Asp.chloromethylketone (YVAD), but sensitive to the CPP32/caspase-3 inhibitor benzyloxycarbonyl-Asp-Glu-Val-Asp.fluoromethylketone (DEVD) and benzyloxycarbonyl-Val-Ala-Asp.fluoromethylketone (zVAD), a caspase inhibitor with broader specificity. This indicated an essential involvement of caspases, but argued against a significant role of ICE/caspase-1 or FLICE/caspase-8. Actinomycin D or cycloheximide prevented cell death, suggesting that, in this system, p53-induced apoptosis depends upon macromolecule biosynthesis. Introduction of functional p53 into CEM cells enhanced their sensitivity to the DNA-damaging agent doxorubicin, but not to the tubulin-active compound vincristine. Thus, mutational p53 inactivation in ALL might entail relative resistance to DNA-damaging, but not to tubulin-destabilizing, chemotherapy.
authors.affiliation: Institute for General and Experimental Pathology, Division of Molecular Pathophysiology, University of Innsbruck, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Geley
authors.forename: B L
authors.initials: BL
authors.lastname: Hartmann
authors.forename: R
authors.initials: R
authors.lastname: Hattmannstorfer
authors.forename: M
authors.initials: M
authors.lastname: Löffler
authors.forename: M J
authors.initials: MJ
authors.lastname: Ausserlechner
authors.forename: D
authors.initials: D
authors.lastname: Bernhard
authors.forename: R
authors.initials: R
authors.lastname: Sgonc
authors.forename: E M
authors.initials: EM
authors.lastname: Strasser-Wozak
authors.forename: M
authors.initials: M
authors.lastname: Ebner
authors.forename: B
authors.initials: B
authors.lastname: Auer
authors.forename: R
authors.initials: R
authors.lastname: Kofler
mesh_terms: D000483:Alleles; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D020170:Caspase 1; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases; D003513:Cycloheximide / Q000494:pharmacology; D003546:Cysteine Endopeptidases / Q000502:physiology*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D004317:Doxorubicin / Q000494:pharmacology; D019008:Drug Resistance, Neoplasm; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects; D016158:Genes, p53; D006579:Heterozygote; D006801:Humans; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000473:pathology*; D009363:Neoplasm Proteins / Q000235:genetics / Q000502:physiology*; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D010641:Phenotype; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011993:Recombinant Fusion Proteins / Q000502:physiology; D013696:Temperature; D014162:Transfection; D014404:Tubulin / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000187:drug effects; D016159:Tumor Suppressor Protein p53 / Q000502:physiology*; D014750:Vincristine / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D015853:Cysteine Proteinase Inhibitors; D004791:Enzyme Inhibitors; D009363:Neoplasm Proteins; D019384:Nucleic Acid Synthesis Inhibitors; D011500:Protein Synthesis Inhibitors; D011993:Recombinant Fusion Proteins; D014404:Tubulin; D016159:Tumor Suppressor Protein p53; D003609:Dactinomycin; D014750:Vincristine; D004317:Doxorubicin; D003513:Cycloheximide; D011065:Poly(ADP-ribose) Polymerases; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases; D003546:Cysteine Endopeptidases; D020170:Caspase 1