COX-2 expression in canine normal and neoplastic mammary gland.
COX-2 expression was examined immunohistochemically in samples of normal canine mammary tissue (n=22) and benign (n=36) and malignant (n=45) mammary tumours including metastases (n=12). COX-2 was constitutively expressed in normal mammary tissue with membranous apical labelling of glandular epithelium, suggesting a role for this molecule in normal mammary physiology. By contrast, in neoplastic lesions and in adjacent non-neoplastic mammary tissue COX-2 was expressed in the cytoplasm of epithelial cells, suggesting that internalization of the molecule is associated with oncogenesis. Marked expression of COX-2 was observed in 8.3% of benign neoplasms and in 42.2% of malignant neoplasms, mainly in poorly differentiated areas. The majority of metastatic lesions (58.3%) exhibited strong COX-2 labelling and in almost all cases (83.3%) the labelling intensity was similar or stronger to that of the primary neoplasm. This finding is consistent with the hypothesis that COX-2 metabolites are important promoters of angiogenesis and invasiveness and therefore contribute to metastatic spread.
Dias Pereira
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Instituto de Ciências Biomédicas Abel Salazar. pdiaspereira@yahoo.com.br
Lopes
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CC
Matos
A J F
AJ
Santos
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M
Gärtner
F
F
Medeiros
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Lopes
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D000818:Animals; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D004283:Dog Diseases / Q000201:enzymology* / Q000473:pathology; D004285:Dogs; D005260:Female; D007150:Immunohistochemistry / Q000662:veterinary; D008321:Mammary Glands, Animal / Q000201:enzymology* / Q000378:metabolism; D015674:Mammary Neoplasms, Animal / Q000201:enzymology* / Q000378:metabolism / Q000473:pathology; D009362:Neoplasm Metastasis / Q000473:pathology; D009369:Neoplasms / Q000201:enzymology* / Q000378:metabolism / Q000662:veterinary*
D051546:Cyclooxygenase 2