title: DNA Methylation Profiling in Pheochromocytoma and Paraganglioma Reveals Diagnostic and Prognostic Markers.
abstract: OBJECTIVE
  Pheochromocytoma and paraganglioma (PPGL) are rare neuroendocrine tumors, associated with highly variable postoperative evolution. The scarcity of reliable PPGL prognostic markers continues to complicate patient management. In this study, we explored genome-wide DNA methylation patterns in the context of PPGL malignancy to identify novel prognostic markers.
  
  
  METHODS
  We retrospectively investigated DNA methylation patterns in PPGL with and without metastases using high-throughput DNA methylation profiling data (Illumina 27K) from two large, well-characterized discovery (n = 123; 24 metastatic) and primary validation (n = 154; 24 metastatic) series. Additional validation of candidate CpGs was performed by bisulfite pyrosequencing in a second independent set of 33 paraffin-embedded PPGLs (19 metastatic).
  
  
  RESULTS
  Of the initial 86 candidate CpGs, we successfully replicated 52 (47 genes), associated with metastatic PPGL. Of these, 48 CpGs showed significant associations with time to progression even after correcting for SDHB genotype, suggesting their value as prognostic markers independent of genetic background. Hypermethylation of RDBP (negative elongation factor complex member E) in metastatic tumors was further validated by bisulfite pyrosequencing [Δβmetastatic-benign = 0.29, P = 0.003; HR, 1.4; 95% confidence interval (CI), 1.1-2.0; P = 0.018] and may alter transcriptional networks involving (RERG, GPX3, and PDZK1) apoptosis, invasion, and maintenance of DNA integrity.
  
  
  CONCLUSIONS
  This is the first large-scale study of DNA methylation in metastatic PPGL that identifies and validates prognostic markers, which could be used for stratifying patients according to risk of developing metastasis. Of the three CpGs selected for further validation, one (RDBP) was clearly confirmed and could be used for stratifying patients according to the risk of developing metastases.
authors.affiliation: Hereditary Endocrine Cancer Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain.
authors.forename: Aguirre A
authors.initials: AA
authors.lastname: de Cubas
authors.affiliation: Department of Pathology, Erasmus MC Cancer Institute, University Medical Center, Rotterdam, the Netherlands.
authors.forename: Esther
authors.initials: E
authors.lastname: Korpershoek
authors.affiliation: Hereditary Endocrine Cancer Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain.
authors.forename: Lucia
authors.initials: L
authors.lastname: Inglada-Pérez
authors.affiliation: Programme Cartes d'Identité des Tumeurs, Ligue Nationale Contre Le Cancer, Paris, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Letouzé
authors.affiliation: Hereditary Endocrine Cancer Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Currás-Freixes
authors.affiliation: Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), HUCA, University of Oviedo, Asturias, Spain.
authors.forename: Agustin F
authors.initials: AF
authors.lastname: Fernández
authors.affiliation: Hereditary Endocrine Cancer Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain.
authors.forename: Iñaki
authors.initials: I
authors.lastname: Comino-Méndez
authors.affiliation: Familial Cancer Clinic, Veneto Institute of Oncology, Padova, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Schiavi
authors.affiliation: Hereditary Endocrine Cancer Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain.
authors.forename: Veronika
authors.initials: V
authors.lastname: Mancikova
authors.affiliation: Institute of Clinical Chemistry and Laboratory Medicine, Technische Universität Dresden, Dresden, Germany. Medical Clinic III, Technische Universität Dresden, Dresden, Germany.
authors.forename: Graeme
authors.initials: G
authors.lastname: Eisenhofer
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Mannelli
authors.affiliation: Familial Cancer Clinic, Veneto Institute of Oncology, Padova, Italy. Department of Medicine, University of Padova, Padova, Italy.
authors.forename: Guiseppe
authors.initials: G
authors.lastname: Opocher
authors.affiliation: Internal Medicine, Radboud University Medical Centre, Nijmegen, the Netherlands.
authors.forename: Henri
authors.initials: H
authors.lastname: Timmers
authors.affiliation: Department of Internal Medicine IV Campus Innenstadt, University-Hospital, Ludwig-Maximilians-University of Munich, Munich, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Beuschlein
authors.affiliation: Department of Pathology, Josephine Nefkens Institute, Erasmus MC University Medical Center, Rotterdam, the Netherlands.
authors.forename: Ronald
authors.initials: R
authors.lastname: de Krijger
authors.affiliation: Hereditary Endocrine Cancer Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Cascon
authors.affiliation: Hereditary Endocrine Cancer Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Rodríguez-Antona
authors.affiliation: Cancer Epigenetics Laboratory, Institute of Oncology of Asturias (IUOPA), HUCA, University of Oviedo, Asturias, Spain. Department of Immunology and Oncology, National Center for Biotechnology, CNB-CSIC, Cantoblanco, Madrid, Spain.
authors.forename: Mario F
authors.initials: MF
authors.lastname: Fraga
authors.affiliation: INSERM, UMR970, Paris-Cardiovascular Research Center (PARCC), Paris, France. Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
authors.forename: Judith
authors.initials: J
authors.lastname: Favier
authors.affiliation: INSERM, UMR970, Paris-Cardiovascular Research Center (PARCC), Paris, France. Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris, France. Service de Génétique, Assistance Publique Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Paris, France. Rare Adrenal Cancer Network-Cortico Médullosurrénale Tumeur Endocrine, Institut National du Cancer, Paris, France.
authors.forename: Anne-Paule
authors.initials: AP
authors.lastname: Gimenez-Roqueplo
authors.affiliation: Hereditary Endocrine Cancer Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain. mrobledo@cnio.es.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Robledo
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000175:diagnosis / Q000235:genetics*; D000328:Adult; D014408:Biomarkers, Tumor / Q000235:genetics*; D018899:CpG Islands; D019175:DNA Methylation; D005260:Female; D006801:Humans; D008297:Male; D010235:Paraganglioma / Q000175:diagnosis / Q000235:genetics*; D010673:Pheochromocytoma / Q000175:diagnosis / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics
chemical_list: D014408:Biomarkers, Tumor; D014157:Transcription Factors; C118437:negative elongation factor