title: Targeting the hypoxia inducible factor pathway with mitochondrial uncouplers.
abstract: Hypoxia inducible factor-1 (HIF-1) is central to most adaptation responses of tumors to hypoxia, and consists of a hypoxia inducible HIF-1alpha or -2alpha subunit, and a constitutively expressed HIF-1beta subunit. Previously, mitochondrial uncouplers, rottlerin and FCCP, were shown to increase the rate of cellular O(2 )consumption. In this study, we determined that mitochondrial uncouplers, rottlerin and FCCP, significantly decreased hypoxic as well as normoxic HIF-1 transcriptional activity which was in part mediated by down-regulation of the oxygen labile HIF-1alpha and HIF-2alpha protein levels in PC-3 and DU-145 prostate cancer cells. Our results also revealed that mitochondrial uncouplers decreased the expression of HIF target genes, VEGF and VEGF receptor-2. Taken together, our results indicate that functional mitochondria are important in HIF-1alpha and HIF-2alpha protein stability and transcriptional activity during normoxia as well as in hypoxia, and that mitochondrial uncouplers may be useful in the inhibition of HIF pathway in tumors.
authors.affiliation: Department of Molecular Biology and Immunology, University of North Texas Health Science Center, Fort Worth, TX 76107, USA.
authors.forename: Rusha
authors.initials: R
authors.lastname: Thomas
authors.forename: Myoung H
authors.initials: MH
authors.lastname: Kim
mesh_terms: D000098:Acetophenones / Q000378:metabolism; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D001578:Benzopyrans / Q000378:metabolism; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000378:metabolism; D045744:Cell Line, Tumor; D048430:Cell Shape; D003676:Deferoxamine / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000378:metabolism; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D006801:Humans; D000860:Hypoxia; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism*; D007476:Ionophores / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D017262:Siderophores / Q000378:metabolism; D014475:Uncoupling Agents / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics / Q000378:metabolism; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D000098:Acetophenones; D051792:Basic Helix-Loop-Helix Proteins; D001578:Benzopyrans; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D003676:Deferoxamine; D004791:Enzyme Inhibitors; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007476:Ionophores; D017262:Siderophores; D014475:Uncoupling Agents; D042461:Vascular Endothelial Growth Factor A; D040301:Vascular Endothelial Growth Factor Receptor-2; D000099162:Endothelial PAS Domain-Containing Protein 1; C085746:rottlerin