title: Hemangioblastoma stromal cells show committed stem cell phenotype.
abstract: BACKGROUND
  Hemangioblastomas are benign vascular tumors of the central nervous system that occur sporadically or in association with von Hippel-Lindau disease. These tumors are characteristically composed of a dense capillary network with intervening stromal/interstitial cells. To date, the histogenesis of hemangioblastoma remains unclear. We hypothesize that hemangioblastomas arise from a defective mesodermal stem cell, which gives rise to the atypical vasculature.
  
  
  METHODS
  To test our hypothesis, we have characterized the cellular composition of hemangioblastomas by immunophenotyping pluripotent and committed stem cells and vascular endothelial cells.
  
  
  RESULTS
  Our findings show that hemangioblastoma endothelial cells are positive for CD133, a stem and progenitor cell marker. Vascular endothelial cells also expressed nuclear Oct4. In addition to the endothelium, both CD133 and Oct4 were present in stromal and perivascular cells. Interestingly, neither the endothelium nor the stromal cells expressed Sox2 or Nanog suggesting a committed stem cell phenotype.
  
  
  CONCLUSIONS
  From these findings, we believe that hemangioblastoma stromal cells are committed stem cells producing both vascular cell types. The findings also show an unusual CD133-positive endothelial phenotype in hemangioblastoma.
authors.affiliation: Department of Pathology, University of Western Ontario.
authors.forename: Cassandra M
authors.initials: CM
authors.lastname: Welten
authors.forename: Emily C
authors.initials: EC
authors.lastname: Keats
authors.forename: Lee-Cyn
authors.initials: LC
authors.lastname: Ang
authors.forename: Zia A
authors.initials: ZA
authors.lastname: Khan
mesh_terms: D000071916:AC133 Antigen; D000199:Actins / Q000378:metabolism; D000328:Adult; D015703:Antigens, CD / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D002528:Cerebellar Neoplasms / Q000473:pathology*; D005260:Female; D051272:Glucose Transporter Type 1 / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism; D018325:Hemangioblastoma / Q000473:pathology*; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3 / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D055748:SOXB1 Transcription Factors / Q000378:metabolism; D013234:Stem Cells / Q000502:physiology*; D017154:Stromal Cells / Q000502:physiology*
chemical_list: D000071916:AC133 Antigen; C541116:ACTA2 protein, human; D000199:Actins; D015703:Antigens, CD; D051272:Glucose Transporter Type 1; D006023:Glycoproteins; C497442:HIF1A protein, human; D018398:Homeodomain Proteins; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; C486780:NANOG protein, human; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; C000606023:PROM1 protein, human; D010455:Peptides; D019408:Platelet Endothelial Cell Adhesion Molecule-1; C527782:SOX2 protein, human; D055748:SOXB1 Transcription Factors; D019009:Proto-Oncogene Proteins c-kit; D010751:Phosphopyruvate Hydratase