Immunohistochemical expression of galectin-3 in canine mammary tumours.

Galectin-3, an endogenous beta-galactoside-binding protein, plays a significant role in cell growth, cell activation, and cell to extracellular matrix interactions. To define the role of galectin-3 in canine mammary tumours, its expression was determined in mammary samples by immunohistochemical methods. In adjacent normal mammary glands, distant from the neoplasm, mammary epithelial cells showed little or no expression of galectin-3. In the majority of adenomas, the neoplastic cells showed moderate to strong galectin-3 immunoreactivity, but in the majority of adenocarcinomas such immunoreactivity was weak. These results suggest that the progression of canine mammary tumours is associated with low galectin-3 expression.