Expression of E-cadherin, alpha, beta and gamma-catenin in human colorectal cancer.

E-cadherin is a calcium-dependant cell-cell adhesion molecule that plays a key role in the maintenance of tissue integrity. Its function is mediated by a group of cytoplasmic proteins termed catenins. Loss or dysfunction of E-cadherin has been implicated in the gain of tumour cell invasive potential, a crucial requirement of metastasising tumour cells. This study examined the expression of E-cadherin, alpha-, beta- and gamma-catenin in a series of colorectal cancer patients. Western blotting and immunohistochemical staining demonstrated the frequent loss of E-cadherin and alpha-catenin in 50% and 41% of these samples respectively. Increased levels of beta-catenin were seen in 41% of cases; no significant change in gamma-catenin was observed. We conclude that alterations in the levels of both catenins and E-cadherin within tumour tissue may lead to increased cancer cell invasive potential and thus could play a role in the initiation of the early stages of metastatic spread.