title: Role of VHL, HIF1A and SDH on the expression of miR-210: Implications for tumoral pseudo-hypoxic fate.
abstract: The hypoxia-inducible factor 1α (HIF-1α) and its microRNA target, miR-210, are candidate tumor-drivers of metabolic reprogramming in cancer. Neuroendocrine neoplasms such as paragangliomas (PGLs) are particularly appealing for understanding the cancer metabolic adjustments because of their associations with deregulations of metabolic enzymes, such as succinate dehydrogenase (SDH), and the von Hippel Lindau (VHL) gene involved in HIF-1α stabilization. However, the role of miR-210 in the pathogenesis of SDH-related tumors remains an unmet challenge. Herein is described an in vivo genetic analysis of the role of VHL, HIF1A and SDH on miR-210 by using knockout murine models, siRNA gene silencing, and analyses of human tumors. HIF-1α knockout abolished hypoxia-induced miR-210 expression in vivo but did not alter its constitutive expression in paraganglia. Normoxic miR-210 levels substantially increased by complete, but not partial, VHL silencing in paraganglia of knockout VHL-mice and by over-expression of p76del-mutated pVHL. Similarly, VHL-mutated PGLs, not those with decreased VHL-gene/mRNA dosage, over-expressed miR-210 and accumulate HIF-1α in most tumor cells. Ablation of SDH activity in SDHD-null cell lines or reduction of the SDHD or SDHB protein levels elicited by siRNA-induced gene silencing did not induce miR-210 whereas the presence of SDH mutations in PGLs and tumor-derived cell lines was associated with mild increase of miR-210 and the presence of a heterogeneous, HIF-1α-positive and HIF-1α-negative, tumor cell population. Thus, activation of HIF-1α is likely an early event in VHL-defective PGLs directly linked to VHL mutations, but it is a late event favored but not directly triggered by SDHx mutations. This combined analysis provides insights into the mechanisms of HIF-1α/miR-210 regulation in normal and tumor tissues potentially useful for understanding the pathogenesis of cancer and other diseases sharing similar underpinnings.
authors.affiliation: Otorhinolaryngology Service, Hospital Universitario Central de Asturias, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, CIBERONC, Oviedo, Spain.
authors.forename: Anna
authors.initials: A
authors.lastname: Merlo
authors.affiliation: Otorhinolaryngology Service, Hospital Universitario Central de Asturias, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, CIBERONC, Oviedo, Spain.
authors.forename: Cristóbal
authors.initials: C
authors.lastname: Bernardo-Castiñeira
authors.affiliation: Otorhinolaryngology Service, Hospital Universitario Central de Asturias, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, CIBERONC, Oviedo, Spain.
authors.forename: Inés
authors.initials: I
authors.lastname: Sáenz-de-Santa-María
authors.affiliation: Service of Molecular Oncology, Hospital Universitario Central de Asturias, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, Oviedo, Spain.
authors.forename: Ana S
authors.initials: AS
authors.lastname: Pitiot
authors.affiliation: Service of Molecular Oncology, Hospital Universitario Central de Asturias, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, Oviedo, Spain.
authors.forename: Milagros
authors.initials: M
authors.lastname: Balbín
authors.affiliation: Service of Pathology, Hospital Universitario Central de Asturias, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, Oviedo, Spain.
authors.forename: Aurora
authors.initials: A
authors.lastname: Astudillo
authors.affiliation: Service of Endocrinology and Nutrition, Hospital Universitario Central de Asturias, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, Oviedo, Spain.
authors.forename: Nuria
authors.initials: N
authors.lastname: Valdés
authors.affiliation: Otorhinolaryngology Service, Hospital Gregorio Marañón, Madrid, Spain.
authors.forename: Bartolomé
authors.initials: B
authors.lastname: Scola
authors.affiliation: Stem Cell Niche Pathophysiology Group, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain.|Department of Cardiovascular Physiopahology, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío, CSIC, Universidad de Sevilla, Sevilla, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Del Toro
authors.affiliation: Stem Cell Niche Pathophysiology Group, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain.|Stem Cell Institute and Department of Haematology, University of Cambridge and National Health Service Blood and Transplant, Cambridge Biomedical Campus, UK.
authors.forename: Simón
authors.initials: S
authors.lastname: Méndez-Ferrer
authors.affiliation: Department of Cardiovascular Physiopahology, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío, CSIC, Universidad de Sevilla, Sevilla, Spain.
authors.forename: José I
authors.initials: JI
authors.lastname: Piruat
authors.affiliation: Otorhinolaryngology Service, Hospital Universitario Central de Asturias, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, CIBERONC, Oviedo, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Suarez
authors.affiliation: Otorhinolaryngology Service, Hospital Universitario Central de Asturias, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, CIBERONC, Oviedo, Spain.
authors.forename: María-Dolores
authors.initials: MD
authors.lastname: Chiara
mesh_terms: D000328:Adult; D000818:Animals; D045744:Cell Line, Tumor; D005260:Female; D017353:Gene Deletion; D015972:Gene Expression Regulation, Neoplastic; D020022:Genetic Predisposition to Disease; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism*; D008297:Male; D018345:Mice, Knockout; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D010235:Paraganglioma / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D010641:Phenotype; D055550:Protein Stability; D034622:RNA Interference; D015398:Signal Transduction; D013385:Succinate Dehydrogenase / Q000235:genetics* / Q000378:metabolism*; D014162:Transfection; D000072258:Tumor Hypoxia; D059016:Tumor Microenvironment; D051794:Von Hippel-Lindau Tumor Suppressor Protein / Q000235:genetics* / Q000378:metabolism
chemical_list: C497442:HIF1A protein, human; C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; C543800:MIRN210 microRNA, human; C549325:MIRN210 microRNA, mouse; D035683:MicroRNAs; D013385:Succinate Dehydrogenase; D051794:Von Hippel-Lindau Tumor Suppressor Protein; C497446:VHL protein, human; C494469:VHL protein, mouse
keywords: hypoxia inducible factor; miR-210; paragangliomas; succinate dehydrogenase; von hippel lindau