title: Up-regulation of hypoxia-inducible factor-1alpha is not sufficient for hypoxic/anoxic p53 induction.
abstract: Oxygen-deprived regions of a solid tumor can induce tumor suppressor p53 expression and hence select for p53-mutant tumor cells with diminished apoptotic potential. It has been proposed that the hypoxia-inducible factor-1 (HIF-1) alpha subunit binds to p53 and protects it from proteasomal degradation. However, we found that hypoxic conditions that strongly induce HIF-1-dependent endogenous gene expression as well as HIF-1alpha protein neither induce p53-dependent gene expression nor p53 protein. The iron chelator deferoxamine induced both HIF-1alpha and p53, but p53 up-regulation could still be detected in HIF-1alpha-deficient cells, suggesting that mechanisms other than HIF-1alpha activation contribute to oxygen-regulated p53 induction.
authors.affiliation: Institute of Physiology, University of Zürich-Irchel, Zürich, Switzerland.
authors.forename: R H
authors.initials: RH
authors.lastname: Wenger
authors.forename: G
authors.initials: G
authors.lastname: Camenisch
authors.forename: I
authors.initials: I
authors.lastname: Desbaillets
authors.forename: D
authors.initials: D
authors.lastname: Chilov
authors.forename: M
authors.initials: M
authors.lastname: Gassmann
mesh_terms: D000818:Animals; D051784:Aryl Hydrocarbon Receptor Nuclear Translocator; D015687:Cell Hypoxia; D004268:DNA-Binding Proteins / Q000378:metabolism*; D003676:Deferoxamine / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic; D016158:Genes, p53; D006801:Humans; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D051379:Mice; D009687:Nuclear Proteins / Q000378:metabolism*; D018336:Receptors, Aryl Hydrocarbon; D014157:Transcription Factors / Q000378:metabolism; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
chemical_list: C497396:ARNT protein, human; C497397:Arnt protein, mouse; D004268:DNA-Binding Proteins; C497442:HIF1A protein, human; C497443:Hif1a protein, mouse; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009687:Nuclear Proteins; D018336:Receptors, Aryl Hydrocarbon; D014157:Transcription Factors; D051784:Aryl Hydrocarbon Receptor Nuclear Translocator; D003676:Deferoxamine