Altered E-cadherin/β-catenin expression in feline cutaneous squamous cell carcinomas.

Cutaneous squamous cell carcinoma (CSCC) is the most common malignant skin tumour in cats and the nature of the molecular mechanisms involved is poorly defined. Included among the molecular mechanisms in human and canine CSCCs is altered expression of E-cadherin/β-catenin. This study aimed to explore the immunohistochemical expression pattern of E-cadherin and β-catenin in 43 samples of feline CSCC by using a tissue microarray to elucidate whether expression of these molecules is dysregulated. Membrane expression of E-cadherin and membrane and cytoplasmic expression of β-catenin were significantly reduced in the CSCCs. Cytoplasmic expression of E-cadherin and nuclear expression of β-catenin were also found in some CSCCs. These findings indicate that altered expression of E-cadherin and β-catenin is a frequent event in feline CSCCs, suggesting that these molecules play an important role in acquisition of the malignant phenotype in feline patients with CSCC. The results also suggest the existence of a subpopulation of feline patients with CSCC in which the Wnt pathway may contribute to epidermal carcinogenesis.