title: RNA Activation of the Vascular Endothelial Growth Factor Gene (VEGF) Promoter by Double-Stranded RNA and Hypoxia: Role of Noncoding VEGF Promoter Transcripts.
abstract: RNA activation (RNAa) is a gene regulation process in which promoter-targeted short double-stranded RNAs (dsRNAs) or microRNAs (miRs) induce target gene expression at the transcriptional level. Here, we investigate the presence of cryptic promoter transcripts within the VEGF promoter. Single-strand sense and antisense noncoding vascular endothelial growth factor (NcVEGF) promoter transcripts are identified, and their respective expression is studied in cells transfected with a VEGF promoter targeted dsRNA, namely, dsVEGF706, in hypoxic cells and in human malignant lung tissues. Interestingly, in dsVEGF706-transfected, as well as in hypoxic cells, NcVEGF expression levels increase coordinately with coding VEGF expression. Ago2 interaction with both sense and antisense NcVEGFs is increased in hypoxic cells, whereas in dsVEGF706-transfected cells, Ago2 and the antisense strand of the dsRNA interact specifically with the sense NcVEGF transcript. Furthermore, both dsVEGF706 and ectopic NcVEGF transcripts are able to activate the VEGF promoter endogenously present or in a reporter construct. Finally, using small interfering RNA targeting Ago2, we show that RNAa plays a role in the maintenance of increased VEGF and NcVEGF expression after hypoxia. Given the central role of VEGF in major human diseases, including cancer, this novel molecular mechanism is poised to reveal promising possibilities for therapeutic interventions.
authors.affiliation: INSERM, U1081, Institute for Research on Cancer and Aging of Nice, Aging and Diabetes Team, Nice, France CNRS, UMR 7284, Institute for Research on Cancer and Aging of Nice, Nice, France Faculty of Medicine, Institute for Research on Cancer and Aging of Nice, University Nice-Sophia-Antipolis, Nice, France pascal.lopez@unice.fr.
authors.forename: Pascal
authors.initials: P
authors.lastname: Lopez
authors.affiliation: INSERM, U1081, Institute for Research on Cancer and Aging of Nice, Aging and Diabetes Team, Nice, France CNRS, UMR 7284, Institute for Research on Cancer and Aging of Nice, Nice, France Faculty of Medicine, Institute for Research on Cancer and Aging of Nice, University Nice-Sophia-Antipolis, Nice, France.
authors.forename: Kay-Dietrich
authors.initials: KD
authors.lastname: Wagner
authors.affiliation: INSERM, U1081, Institute for Research on Cancer and Aging of Nice, Aging and Diabetes Team, Nice, France CNRS, UMR 7284, Institute for Research on Cancer and Aging of Nice, Nice, France Laboratory of Clinical and Experimental Pathology and Hospital-Related Biobank (BB-0033-00025), University Hospital, Nice, France FHU OncoAge, University Nice-Sophia-Antipolis, Nice, France.
authors.forename: Paul
authors.initials: P
authors.lastname: Hofman
authors.affiliation: INSERM, U1081, Institute for Research on Cancer and Aging of Nice, Aging and Diabetes Team, Nice, France CNRS, UMR 7284, Institute for Research on Cancer and Aging of Nice, Nice, France Faculty of Medicine, Institute for Research on Cancer and Aging of Nice, University Nice-Sophia-Antipolis, Nice, France FHU OncoAge, University Nice-Sophia-Antipolis, Nice, France Clinical Chemistry Laboratory, University Hospital, Nice, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Van Obberghen
mesh_terms: D060565:Argonaute Proteins / Q000378:metabolism*; D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic; D006367:HeLa Cells; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012330:RNA, Double-Stranded / Q000235:genetics*; D022661:RNA, Untranslated / Q000235:genetics*; D015533:Transcriptional Activation; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics*
chemical_list: C466422:AGO2 protein, human; D060565:Argonaute Proteins; D012330:RNA, Double-Stranded; D022661:RNA, Untranslated; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A