Changes of E-cadherin and beta-catenin in human and mouse intestinal tumours

An immunohistochemical analysis of E-cadherin and beta -catenin was perform ed in human colorectal cancer as well as in surrounding normal intestinal t issue. We also analysed the expression of these two cell adhesion proteins in transgenic Apc1638N mice as a model of human familial adenometous polypo sis syndrome. In the normal intestinal mucosa of both species, E-cadherin a nd beta -catenin were localized along the lateral plasma membrances of epit helial cells. In intestinal tumour cells, however, they were also present i n the cytoplasm. The expression of both proteins was reduced in human and m ouse tumours. The pattern of their distribution was frequently heterogenous with strongly positive cells in a mosaic of negative ones. Further, E-cadh erin and beta -catenin expression did not correlate to the Duke's staging o f tumours and therefore neither can be used as prognostic criteria.