title: Expression of beta-catenin, E-cadherin and APC in canine mammary tumors.
abstract: BACKGROUND
  Mammary tumors are a very common neoplasm in the dog and show histological features and biological behaviour similar to human mammary carcinomas. Recently, a pathway named Wnt-1, involving beta-catenin and APC protein, has emerged as an important player in many human tumor types, including mammary neoplasms.
  
  
  METHODS
  Thirty-five samples of canine mammary tumors (10 benign and 25 malignant) were studied in order to evaluate the co-expression of beta-catenin, APC protein and E cadherin with confocal laser microscopical observation, by western blot analysis and by correlating data obtained with the histological grade of tumours.
  
  
  RESULTS
  A progressive decrease of E-cadherin together with disruption of beta-catenin expression was observed in less differentiated malignant tumors. In addition, a loss of beta-catenin membranous distribution and a cytoplasmic accumulation was often coexpressed with disrupted expression of APC protein. Western blot analysis showed a progressive increase of beta-catenin in malignant tumors, which could be the expression of disrupted /-catenin catabolism leading to cytoplasmic accumulation. In some less differentiated malignant tumors, a marked beta-catenin decrease was also observed. This feature could be linked to mutations in beta-catenin gene coding for a truncated and lighter protein.
  
  
  CONCLUSIONS
  These results may indicate the multifunctional role played by beta-catenin in canine mammary oncogenesis.
authors.affiliation: Departments of Pathology and Animal Health, Faculty of Veterinary Medicine, University Federico II, Naples, Italy.
authors.forename: Brunella
authors.initials: B
authors.lastname: Restucci
authors.forename: Paola
authors.initials: P
authors.lastname: Maiolino
authors.forename: Manuela
authors.initials: M
authors.lastname: Martano
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Esposito
authors.forename: Daniele
authors.initials: D
authors.lastname: De Filippis
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Borzacchiello
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Lo Muzio
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D025601:Adenomatous Polyposis Coli Protein / Q000096:biosynthesis*; D000818:Animals; D015153:Blotting, Western; D015820:Cadherins / Q000096:biosynthesis*; D004283:Dog Diseases / Q000378:metabolism* / Q000473:pathology; D004285:Dogs; D005455:Fluorescent Antibody Technique; D015674:Mammary Neoplasms, Animal / Q000378:metabolism* / Q000473:pathology; D018613:Microscopy, Confocal; D051176:beta Catenin / Q000096:biosynthesis*
chemical_list: D025601:Adenomatous Polyposis Coli Protein; D015820:Cadherins; D051176:beta Catenin