IMMUNOHISTOCHEMICAL ANALYSIS OF E-CADHERIN EXPRESSION IN HUMAN COLORECTAL TUMORS

The homotypic homophilic cell-cell adhesion molecule E-cadherin is cru cial in the organization and maintenance of most epithelia. The expres sion of E-cadherin was studied immunohistochemically in various human colorectal tumours. Therefore we stained 1 tubular adenoma with low gr ade dysplasia, 18 adenocarcinomas with different histologic degrees of differentiation and invasion, and 1 metastasis using a modified perox idase-anti-peroxidase technique. In the adenoma as well as in all well differentiated adenocarcinomas we found E-cadherin immunopositivity a t the cell membrane of almost all cancer cells. The immunopositivity o f E-cadherin was clearly weaker and sometimes even absent in isolated neoplastic cells and glands of less differentiated adenocarcinomas. Th e moderately differentiated adenocarcinomas showed an intermediate sta ining pattern. These findings are in line with experimental evidence t hat downregulation of E-cadherin favours invasion, eventually leading to metastasis.