title: RNA interference for HIF-1alpha inhibits its downstream signalling and affects cellular proliferation.
abstract: Transcription factor HIF-1 is a key determinant of oxygen-dependent gene regulation. Suppression of HIF-1alpha is important for exploring HIF-1-dependent processes and for interfering with hypoxia-induced pathophysiological events. This study applied RNA-interference targeting HIF-1alpha to the human lung A549 cell line. Transfection of HIF-1alpha-siRNA reduced HIF-1alpha synthesis as measured on mRNA and protein level by realtime RT-PCR, Western blot, and immuncytochemistry. A time kinetic for hypoxic stabilization of HIF-1alpha protein and its inhibition by HIF-1alpha-siRNA is included. Hypoxic induction of HIF-1-controlled target genes as heme oxygenase I (HO-1), phosphoglycerate kinase (PGK), and vascular endothelial growth factor (VEGF) was markedly attenuated by HIF-1alpha-siRNA treatment. Correspondingly, gene activation via hypoxia-responsive-element, as shown by reporter gene assay, was inhibited by HIF-1alpha-siRNA. Moreover, this approach was found to suppress the shift from from S-phase to G1-phase observed in A549 cells in response to hypoxia, supporting a role of HIF-1alpha in oxygen-dependent cell cycle regulation.
authors.affiliation: Department of Internal Medicine 2, Klinikstr. 36, Medical School of the Justus-Liebig-University, Giessen D-35392, Germany. joerg.haenze@innere.med.uni-giessen.de
authors.forename: Jörg
authors.initials: J
authors.lastname: Hänze
authors.forename: Bastian G
authors.initials: BG
authors.lastname: Eul
authors.forename: Rajkumar
authors.initials: R
authors.lastname: Savai
authors.forename: Stefanie
authors.initials: S
authors.lastname: Krick
authors.forename: Parag
authors.initials: P
authors.lastname: Goyal
authors.forename: Friedrich
authors.initials: F
authors.lastname: Grimminger
authors.forename: Werner
authors.initials: W
authors.lastname: Seeger
authors.forename: Frank
authors.initials: F
authors.lastname: Rose
mesh_terms: D002455:Cell Division / Q000502:physiology; D002460:Cell Line; D015536:Down-Regulation / Q000235:genetics*; D006801:Humans; D000860:Hypoxia / Q000235:genetics / Q000378:metabolism*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D034622:RNA Interference / Q000502:physiology*; D020545:Respiratory Mucosa / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*
chemical_list: C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D014157:Transcription Factors