title: Clinicopathological significance of immunoexpression of claudin-1 and claudin-7 in feline mammary carcinomas.
abstract: Claudins (CLDNs) are tight junction proteins that have a role in regulating cell adhesion and polarity, paracellular permeability, proliferation and differentiation. Several immunohistochemical studies have shown reduced expression of CLDN-1 and CLDN-7 in human and canine mammary carcinomas, suggesting that these proteins may participate in mammary carcinogenesis, invasion and metastasis. The present study characterizes expression of CLDN-1 and CLDN-7 in feline mammary carcinomas (n = 52) and their metastases (n = 29). There was an inverse association between CLDN-7 expression and histological grade of tumour. Reduced expression of CLDN-7 was significantly associated with decreased tubule formation, high proliferative activity and metastasis. No significant associations were found between CLDN-1 expression and any of these features. Evaluation of expression of CLDN-7, but not CLDN-1, may therefore provide prognostic information, assisting in the diagnosis of a subgroup of aggressive feline mammary carcinomas that share some features with the recently described 'claudin-low' subgroup of human breast cancer.
authors.affiliation: Instituto de Ciências Biomédicas de Abel Salazar, University of Porto, Rua Jorge Viterbo Ferreira N°228, 4050-313 Porto, Portugal.
authors.forename: A Rute
authors.initials: AR
authors.lastname: Flores
authors.affiliation: Instituto de Ciências Biomédicas de Abel Salazar, University of Porto, Rua Jorge Viterbo Ferreira N°228, 4050-313 Porto, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Rêma
authors.affiliation: Instituto de Ciências Biomédicas de Abel Salazar, University of Porto, Rua Jorge Viterbo Ferreira N°228, 4050-313 Porto, Portugal.
authors.forename: F
authors.initials: F
authors.lastname: Carvalho
authors.affiliation: Instituto de Ciências Biomédicas de Abel Salazar, University of Porto, Rua Jorge Viterbo Ferreira N°228, 4050-313 Porto, Portugal.
authors.forename: G
authors.initials: G
authors.lastname: Lopes
authors.affiliation: Instituto de Ciências Biomédicas de Abel Salazar, University of Porto, Rua Jorge Viterbo Ferreira N°228, 4050-313 Porto, Portugal.
authors.forename: A
authors.initials: A
authors.lastname: Faustino
authors.affiliation: Instituto de Ciências Biomédicas de Abel Salazar, University of Porto, Rua Jorge Viterbo Ferreira N°228, 4050-313 Porto, Portugal. Electronic address: pdiaspereira@yahoo.com.br.
authors.forename: P
authors.initials: P
authors.lastname: Dias Pereira
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000032:analysis*; D002371:Cat Diseases / Q000378:metabolism / Q000473:pathology*; D002415:Cats; D062445:Claudin-1 / Q000032:analysis / Q000096:biosynthesis; D057167:Claudins / Q000032:analysis / Q000096:biosynthesis*; D005260:Female; D007150:Immunohistochemistry; D015674:Mammary Neoplasms, Animal / Q000378:metabolism / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; D062445:Claudin-1; D057167:Claudins
keywords: carcinoma; cat; claudin; mammary