Cadherins in renal cell carcinoma.

Distant metastasis is the most predominant clinical problem in renal cell carcinoma. The first step of metastasis is detachment of tumor cells from the primary tumor and subsequent access to the circulation e.g. to lymph or blood vessels. Conceptually, detachment of tumor cells may be facilitated by loss of molecules that provide adhesion of normal cells, such as the cadherins. It has in fact been demonstrated that loss of E-cadherin is associated with invasion and metastasis in animal models and with an unfavorable prognosis in cancer patients. Four major cadherins have been demonstrated in normal kidney and renal cell carcinoma: N-cadherin, E-cadherin, ksp-cadherin, and cadherin 6. The particular role of each of these cadherins in pathogenesis of renal cell carcinoma is not completely understood at present.