title: Ki-67 and vascular endothelial growth factor expression in intracranial meningiomas in dogs.
abstract: BACKGROUND
  Tumor proliferation in human intracranial meningiomas can be defined by the reactivity of the monoclonal antibody MIB-1 to the Ki-67 antigen. Vascular endothelial growth factor (VEGF), a pro-angiogenic factor, is a predictive marker for survival of dogs with intracranial meningiomas.
  
  
  OBJECTIVE
  Ki-67 is expressed in canine intracranial meningiomas and is associated with VEGF expression. Ki-67 expression is a prognostic marker for patient outcome.
  
  
  METHODS
  Seventy client-owned dogs with WHO grade I intracranial meningiomas.
  
  
  METHODS
  Retrospective study assessing the degree of immunostaining for Ki-67 by MIB-1 and VEGF expression in intracranial meningioma tissue from dogs. MIB-1 Labeling Index (LI) was calculated with Image J NIH-software. Extent, intensity, and distribution of VEGF-expression was assessed semiquantitatively. Cross tabulations with Fisher's exact tests and nonparametric Spearman's rank correlations were performed to identify associations between VEGF expression and MIB-1 LI. Fifteen dogs underwent postsurgical radiotherapy and were included in survival analysis. The effect of MIB-1 LI on survival was examined by Kaplan-Meier and Cox proportional hazards regression procedures.
  
  
  RESULTS
  Ki-67 staining was positive in 91% (64/70) and VEGF expression was detected in 96% (67/70). There was no significant association between VEGF expression and MIB-1 LI. MIB-1 LI was not associated with survival.
  
  
  CONCLUSIONS
  MIB-1 antibody can be used to document cell proliferation in intracranial meningiomas in dogs, but does not predict outcome. No association between VEGF as a marker of angiogenesis and tumor proliferation was found. Angiogenesis might be a more important predictor of meningioma activity in dogs than is Ki-67.
authors.affiliation: Centre for Small Animal Studies, Animal Health Trust, Newmarket, UK. lara.matiasek@aht.org.uk
authors.forename: L A
authors.initials: LA
authors.lastname: Matiasek
authors.forename: S R
authors.initials: SR
authors.lastname: Platt
authors.forename: V
authors.initials: V
authors.lastname: Adams
authors.forename: T J
authors.initials: TJ
authors.lastname: Scase
authors.forename: D
authors.initials: D
authors.lastname: Keys
authors.forename: J
authors.initials: J
authors.lastname: Miller
authors.forename: F
authors.initials: F
authors.lastname: Adamo
authors.forename: S
authors.initials: S
authors.lastname: Long
authors.forename: K
authors.initials: K
authors.lastname: Matiasek
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000378:metabolism*; D004285:Dogs; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D019394:Ki-67 Antigen / Q000235:genetics / Q000378:metabolism*; D008579:Meningioma / Q000662:veterinary*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*
chemical_list: D019394:Ki-67 Antigen; D042461:Vascular Endothelial Growth Factor A