Cadherin and integrin regulation of epithelial cell migration.

These studies quantified the relative effects of E-cadherin expression and homophilic ligation on the integrin-mediated motility of epithelial cells. Micropatterned proteins were used to quantitatively titrate the ligation of E-cadherin and integrin receptors in order to assess their coordinate influence on the migration velocities of MDA-MB-231 breast tumor epithelial cells. Fibronectin, E-cadherin, and mixtures of fibronectin and E-cadherin were covalently patterned on solid surfaces at defined compositions and mass coverages. The migration velocities of parental epithelial cells and of cells engineered to express E-cadherin under tetracycline control show that E-cadherin expression reduces cell motility by both adhesion-dependent and adhesion-independent mechanisms. Increasing E-cadherin expression levels also suppresses the dependence of cell velocity on the fibronectin coverage. On E-cadherin-containing substrata, the cell velocity decreases both with the E-cadherin expression level and with the immobilized E-cadherin surface density. These studies thus identified conditions under which E-cadherin preferentially suppresses cell migration by adhesion-independent versus adhesion-dependent mechanisms.