Reduced expression of claudin-2 is associated with high histological grade and metastasis of feline mammary carcinomas.
Claudins (CLDNs) are a family of tight junction (TJ) proteins that play an important role in maintaining cell polarity, in controlling paracellular ion flux and in regulating cell proliferation and differentiation. There is a growing body of evidence that associates changes in CLDN expression with the development of human breast cancer. In the present study CLDN-2 expression was examined immunohistochemically in samples of normal feline mammary tissue (n = 5) and mammary carcinomas (n = 52), including metastatic lesions (n = 29). Seventy-seven percent of carcinomas showed reduced CLDN-2 expression compared with that observed in normal mammary gland. Reduced expression of CLDN-2 was significantly associated with a high histological grade of carcinoma (P = 0.011), with 88.6% of grade II/III carcinomas showing decreased expression. Furthermore, CLDN-2 down-regulation was significantly associated with metastatic disease (P = 0.0027), with 93.1% of cases with signs of metastasis showing decreased expression of this protein. CLDN-2 may constitute a molecular marker for identification of a subgroup of feline mammary carcinomas characterized by high histological grade and the development of metastasis.
Instituto de Ciências Biomédicas de Abel Salazar, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
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Flores
Instituto de Ciências Biomédicas de Abel Salazar, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
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Rêma
Instituto de Ciências Biomédicas de Abel Salazar, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
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Carvalho
Instituto de Ciências Biomédicas de Abel Salazar, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
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Faustino
Instituto de Ciências Biomédicas de Abel Salazar, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal. Electronic address: pdiaspereira@yahoo.com.br.
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Dias Pereira
D000818:Animals; D014408:Biomarkers, Tumor / Q000378:metabolism; D002277:Carcinoma / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D002371:Cat Diseases / Q000378:metabolism / Q000473:pathology*; D002415:Cats; D062446:Claudin-2 / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D007150:Immunohistochemistry; D008321:Mammary Glands, Animal / Q000378:metabolism / Q000473:pathology*; D015674:Mammary Neoplasms, Animal / Q000378:metabolism / Q000473:pathology*; D060787:Neoplasm Grading / Q000662:veterinary; D009362:Neoplasm Metastasis / Q000473:pathology*
D014408:Biomarkers, Tumor; D062446:Claudin-2
carcinoma; cat; claudin-2; mammary