title: Alpha-internexin expression in gliomas: relationship with histological type and 1p, 19q, 10p and 10q status.
abstract: BACKGROUND
  The alpha-internexin (INA) gene encodes an intermediate filament involved in neurogenesis and maps in 10q24.33. A strong INA protein expression has been reported in oligodendroglial tumours and was associated with 1p19q deletion. To assess the relevance of INA immunohistochemistry in glioma typing, this paper studied the relationship between INA expression, histological type, genomic status and patient outcome.
  
  
  METHODS
  The study analysed INA, nestin, Olig2 and p53 expression, loss of heterozygosity of microsatellite markers from telomere to centromere of 10p, 10q, 1p and 19q chromosomes and epidermal growth factor receptor gene (EGFR) amplification in 40 gliomas (five astrocytomas, 12 oligodendrogliomas, 11 oligoastrocytomas, 12 glioblastomas). INA expression was scored as absent, weak (<10% of labelled tumour cells) or strong (>10%).
  
  
  RESULTS
  Oligodendrogliomas showed strong INA and Olig2 expression, and 1p19q whole loss of heterozygosity (wLOH). Astrocytomas and glioblastomas were characterised by no or weak INA expression, high p53 and nestin expression, 10p10q wLOH, and epidermal growth factor receptor amplification. Most oligoastrocytomas had characteristics of astrocytic tumours. All tumours with strong INA expression retained the 10q chromosome arm and, except for one, had a 1p19q wLOH status. However, despite a strong link between INA expression, 1p19q wLOH and 10q retention, discrepancies were observed in 10% of cases. The presence of INA expression, whether weak or strong, was related to a better prognosis.
  
  
  CONCLUSIONS
  INA expression study can be helpful for glioma typing and prognosis determination in combination with other markers. Nevertheless, INA immunohistochemistry cannot replace the genomic analysis to determine 1p19q and 10p10q status.
authors.affiliation: Department of Pathology, Dupuytren University Hospital, Limoges, France.
authors.forename: Karine
authors.initials: K
authors.lastname: Durand
authors.forename: Angélique
authors.initials: A
authors.lastname: Guillaudeau
authors.forename: Isabelle
authors.initials: I
authors.lastname: Pommepuy
authors.forename: Laura
authors.initials: L
authors.lastname: Mesturoux
authors.forename: Alain
authors.initials: A
authors.lastname: Chaunavel
authors.forename: Emilie
authors.initials: E
authors.lastname: Gadeaud
authors.forename: Marion
authors.initials: M
authors.lastname: Porcheron
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Moreau
authors.forename: François
authors.initials: F
authors.lastname: Labrousse
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D002878:Chromosomes, Human, Pair 1; D002879:Chromosomes, Human, Pair 10; D002888:Chromosomes, Human, Pair 19; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D005910:Glioma / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007381:Intermediate Filament Proteins / Q000235:genetics*; D019656:Loss of Heterozygosity; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D007381:Intermediate Filament Proteins; C046643:alpha-internexin