title: Hypoxia-Inducible Factor 2α Mutation-Related Paragangliomas Classify as Discrete Pseudohypoxic Subcluster.
abstract: Recently, activating mutations of the hypoxia-inducible factor 2α gene (HIF2A/EPAS1) have been recognized to predispose to multiple paragangliomas (PGLs) and duodenal somatostatinomas associated with polycythemia, and ocular abnormalities. Previously, mutations in the SDHA/B/C/D, SDHAF2, VHL, FH, PHD1, and PHD2 genes have been associated with HIF activation and the development of pseudohypoxic (cluster-1) PGLs. These tumors overlap in terms of tumor location, syndromic presentation, and noradrenergic phenotype to a certain extent. However, they also differ especially by clinical outcome and by presence of other tumors or abnormalities. In the present study, we aimed to establish additional molecular differences between HIF2A and non-HIF2A pseudohypoxic PGLs. RNA expression patterns of HIF2A PGLs (n=6) from 2 patients were compared with normal adrenal medullas (n=8) and other hereditary pseudohypoxic PGLs (VHL: n=13, SDHB: n=15, and SDHD: n=14). Unsupervised hierarchical clustering showed that HIF2A PGLs made up a separate cluster from other pseudohypoxic PGLs. Significance analysis of microarray yielded 875 differentially expressed genes between HIF2A and other pseudohypoxic PGLs after normalization to adrenal medulla (false discovery rate 0.01). Prediction analysis of microarray allowed correct classification of all HIF2A samples based on as little as three genes (TRHDE, LRRC63, IGSF10; error rate: 0.02). Genes with the highest expression difference between normal medulla and HIF2A PGLs were selected for confirmatory quantitative reverse transcriptase polymerase chain reaction. In conclusion, HIF2A PGLs show a characteristic expression signature that separates them from non-HIF2A pseudohypoxic PGLs. Unexpectedly, the most significantly differentially expressed genes have not been previously described as HIF target genes.
authors.affiliation: 1st Department of Medicine, University Medical Center Schleswig-Holstein, Campus Lübeck, Lübeck, Germany; Section of Medical Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA. Electronic address: stephanie.fliedner@uksh.de.
authors.forename: Stephanie M J
authors.initials: SM
authors.lastname: Fliedner
authors.affiliation: Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Uma
authors.initials: U
authors.lastname: Shankavaram
authors.affiliation: Section of Medical Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Geena
authors.initials: G
authors.lastname: Marzouca
authors.affiliation: Cancer Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Abdel
authors.initials: A
authors.lastname: Elkahloun
authors.affiliation: Section of Medical Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA; 1st Department of Internal Medicine Medical Faculty of P. J. Šafárik University in Košice, Košice, Slovakia.
authors.forename: Ivana
authors.initials: I
authors.lastname: Jochmanova
authors.affiliation: Section of Medical Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA; Institute of Clinical Chemistry & Laboratory Medicine and Department of Medicine III, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Daerr
authors.affiliation: Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
authors.forename: W Marston
authors.initials: WM
authors.lastname: Linehan
authors.affiliation: Department of Internal Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands.
authors.forename: Henri
authors.initials: H
authors.lastname: Timmers
authors.affiliation: Tufts Medical Center, Boston, MA, USA.
authors.forename: Arthur S
authors.initials: AS
authors.lastname: Tischler
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Papaspyrou
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Brieger
authors.affiliation: Department of Pathology, Josephine Nefkens Institute, Erasmus MC-University Medical Center, Rotterdam, The Netherlands; Department of Pathology, Reinier de Graaf Hospital, Delft, The Netherlands.
authors.forename: Ronald
authors.initials: R
authors.lastname: de Krijger
authors.affiliation: Department of Urology, Comenius University, Bratislava, Slovak Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Breza
authors.affiliation: Institute of Clinical Chemistry & Laboratory Medicine and Department of Medicine III, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.
authors.forename: Graeme
authors.initials: G
authors.lastname: Eisenhofer
authors.affiliation: Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Zhengping
authors.initials: Z
authors.lastname: Zhuang
authors.affiliation: 1st Department of Medicine, University Medical Center Schleswig-Holstein, Campus Lübeck, Lübeck, Germany.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Lehnert
authors.affiliation: Section of Medical Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA. Electronic address: karel.pacak@nih.gov.
authors.forename: Karel
authors.initials: K
authors.lastname: Pacak
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics* / Q000378:metabolism; D002648:Child; D016000:Cluster Analysis; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D000860:Hypoxia / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010085:Oxidative Phosphorylation; D010235:Paraganglioma / Q000235:genetics* / Q000378:metabolism; D011485:Protein Binding; D059467:Transcriptome; D055815:Young Adult; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D000099162:Endothelial PAS Domain-Containing Protein 1