The role of tumor cell adhesion as an important factor in formation of distant colorectal metastasis

PURPOSE: The interactions of blood-borne colorectal carcinoma cells with va scular endothelium are important during hematogenous formation of distant m etastases. To adhere to the vessel wall, circulating carcinoma cells that c ome into contact with the microvasculature must resist the tractive forces of the flow of plasma and other circulating cells that tend to detach them from the wall. METHODS: Hydrodynamic adhesion assays have been introduced t o mimic the microcirculation and investigate cell adhesion under flow condi tions. Different aspects of colorectal cancer cell adhesion during hematoge nous formation of distant metastases are summarized and discussed in this r eview. RESULTS: Adhesion of colorectal carcinoma cells to endomethial cells and extracellular matrix is influenced by the presence of fluid flow. Shea r forces atone are able to induce signal transduction events in these cells that result in cell activation and modification of adhesive behavior. CONC LUSIONS: Consideration of fluid dynamics of circulating colorectal cancer c ell movement in the microcirculation leads to new knowledge of in vivo proc esses that are involved in tumor cell adhesion to the vessel wall in host o rgans. Shear forces have been found to influence adhesive properties of col orectal carcinoma cells to endothelial cells and underlying subendothelial extracellular matrix. Understanding the complex processes involved in tumor cell adhesion may result in the development of novel therapeutic strategie s.