Characterization of α-, β- and p120-Catenin Expression in Feline Mammary Tissues and their Relation with E- and P-Cadherin

Background: Abnormal catenin expression has been related to mammary carcinogenesis in both human and canine species and they are considered tumor- and invasion-suppressor molecules; however, in feline mammary tissues they have been scarcely studied. Materials and Methods: The immunohistochemical expression of alpha-, beta- and p120-catenin was studied in a series of normal feline mammary glands, hyperplastic/dysplastic lesions and benign and malignant mammary tumors. Their relationship with clinicopathological parameters and with E- and P-cadherin expression was assessed. Results: Normal tissues, hyperplastic/dysplastic lesions and benign tumors expressed alpha-, beta- and p120-catenin in the membrane of more than 75% of the luminal epithelial cells, while in malignant tumors, there was a reduction in their membranous expression and a p120-catenin cytoplasmic expression in 40%. Reduced alpha-catenin expression was related to tumor features with prognostic value, namely tumor size (p=0.0203) and necrosis (p=0.0205). The expression of alpha-, beta- and p120-catenin were individually related to each other and collectively associated with E-cadherin expression. Conclusion: The results demonstrate a relationship between feline mammary carcinogenesis and decreased expression of catenins, suggesting that they may represent a valuable tool in the diagnosis of feline mammary neoplasms.