title: Aberrant P-cadherin expression is associated to aggressive feline mammary carcinomas.
abstract: BACKGROUND
  Cadherins are calcium-dependent cell-to-cell adhesion glycoproteins playing a critical role in the formation and maintenance of normal tissue architecture. In normal mammary gland, E-cadherin is expressed by luminal epithelial cells, while P-cadherin is restricted to myoepithelial cells. Changes in the expression of classical E- and P-cadherins have been observed in mammary lesions and related to mammary carcinogenesis. P-cadherin and E-cadherin expressions were studied in a series of feline normal mammary glands, hyperplastic/dysplastic lesions, benign and malignant tumours by immunohistochemistry and double-label immunofluorescence.
  
  
  RESULTS
  In normal tissue and in the majority of hyperplastic/dysplastic lesions and benign tumours, P-cadherin was restricted to myoepithelial cells, while 80% of the malignant tumours expressed P-cadherin in luminal epithelial cells. P-cadherin expression was significantly related to high histological grade of carcinomas (p <0.0001), tumour necrosis (p = 0.001), infiltrative growth (p = 0.0051), and presence of neoplastic emboli (p = 0.0401). Moreover, P-cadherin positive carcinomas had an eightfold likelihood of developing neoplastic emboli than negative tumours. Cadherins expression profile in high grade and in infiltrative tumours was similar, the majority expressing P-cadherin, regardless of E-cadherin expression status. The two cadherins were found to be co-expressed in carcinomas with aberrant P-cadherin expression and preserved E-cadherin.
  
  
  CONCLUSIONS
  The results demonstrate a relationship between P-cadherin expression and aggressive biological behaviour of feline mammary carcinomas, suggesting that P-cadherin may be considered an indicator of poor prognosis in this animal species. Moreover, it indicates that, in queens, the aberrant expression of P-cadherin is a better marker of mammary carcinomas aggressive behaviour than the reduction of E-cadherin expression. Further investigation with follow-up studies in feline species should be conducted in order to evaluate the prognostic value of P-cadherin expression in E-cadherin positive carcinomas.
authors.affiliation: Escola Universitária Vasco da Gama (EUVG), Av. José R. Sousa Fernandes, Campus Universitário de Lordemão, Bloco B, Lordemão, 3020-210, Coimbra, Portugal. acfigueira@gmail.com.|Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto (ICBAS-UP), Rua de Jorge Viterbo Ferreira No. 228, 4050-313, Porto, Portugal. acfigueira@gmail.com.|Instituto de Patologia e Imunologia Molecular da Universidade do Porto (IPATIMUP), Rua Dr Roberto Frias s/n, 4200-465, Porto, Portugal. acfigueira@gmail.com.
authors.forename: Ana Catarina
authors.initials: AC
authors.lastname: Figueira
authors.affiliation: Instituto de Patologia e Imunologia Molecular da Universidade do Porto (IPATIMUP), Rua Dr Roberto Frias s/n, 4200-465, Porto, Portugal. cgomes@ipatimup.pt.
authors.forename: Catarina
authors.initials: C
authors.lastname: Gomes
authors.affiliation: Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto (ICBAS-UP), Rua de Jorge Viterbo Ferreira No. 228, 4050-313, Porto, Portugal. joanao@ipatimup.pt.|Instituto de Patologia e Imunologia Molecular da Universidade do Porto (IPATIMUP), Rua Dr Roberto Frias s/n, 4200-465, Porto, Portugal. joanao@ipatimup.pt.
authors.forename: Joana Tavares
authors.initials: JT
authors.lastname: de Oliveira
authors.affiliation: Escola Universitária Vasco da Gama (EUVG), Av. José R. Sousa Fernandes, Campus Universitário de Lordemão, Bloco B, Lordemão, 3020-210, Coimbra, Portugal. hcrvilhena@gmail.com.|Hospital Veterinário do Baixo Vouga (HVBV), Estrada Nacional 1, 355, Segadães, 3750-742, Águeda, Portugal. hcrvilhena@gmail.com.|Centro de Ciência Animal e Veterinária (CECAV), Universidade de Trás-os-Montes e Alto Douro (UTAD), Quinta de Prados, 5000-801, Vila Real, Portugal. hcrvilhena@gmail.com.
authors.forename: Hugo
authors.initials: H
authors.lastname: Vilhena
authors.affiliation: Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto (ICBAS-UP), Rua de Jorge Viterbo Ferreira No. 228, 4050-313, Porto, Portugal. jgc3@mail.icav.up.pt.|Centro de Investigação em Biodiversidade e Recursos Genéticos (CIBIO), Universidade do Porto (UP), Rua Padre Armando Quintas, 4485-661, Vairão, Portugal. jgc3@mail.icav.up.pt.
authors.forename: Júlio
authors.initials: J
authors.lastname: Carvalheira
authors.affiliation: Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto (ICBAS-UP), Rua de Jorge Viterbo Ferreira No. 228, 4050-313, Porto, Portugal. ajmatos@icbas.up.pt.|Centro de Estudos de Ciência Animal (CECA), Instituto de Ciências e Tecnologias Agrárias e Agro Alimentares (ICETA), Universidade do Porto (UP), Rua D. Manuel II, ap° 55142, 4051-401, Porto, Portugal. ajmatos@icbas.up.pt.
authors.forename: Augusto J F
authors.initials: AJ
authors.lastname: de Matos
authors.affiliation: Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto (ICBAS-UP), Rua de Jorge Viterbo Ferreira No. 228, 4050-313, Porto, Portugal. pdiaspereira@yahoo.com.br.
authors.forename: Patrícia Dias
authors.initials: PD
authors.lastname: Pereira
authors.affiliation: Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto (ICBAS-UP), Rua de Jorge Viterbo Ferreira No. 228, 4050-313, Porto, Portugal. fgartner@ipatimup.pt.|Instituto de Patologia e Imunologia Molecular da Universidade do Porto (IPATIMUP), Rua Dr Roberto Frias s/n, 4200-465, Porto, Portugal. fgartner@ipatimup.pt.
authors.forename: Fátima
authors.initials: F
authors.lastname: Gärtner
mesh_terms: D000818:Animals; D015820:Cadherins / Q000378:metabolism*; D002371:Cat Diseases / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D002415:Cats; D005260:Female; D005455:Fluorescent Antibody Technique / Q000662:veterinary; D008207:Lymphatic Metastasis; D008321:Mammary Glands, Animal / Q000378:metabolism / Q000473:pathology; D015674:Mammary Neoplasms, Animal / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D011379:Prognosis
chemical_list: D015820:Cadherins