Background: The clinical behavior of colorectal cancer depends on its ability to invade and metastasize. Metastatic cells must dissociate from other cells and invade through basement membrane and stroma. Cell-cell adhesion in epithelial cells is mediated by the cell surface protein E-cadherin in association with alpha- and beta-catenin, which link E-cadherin to the cytoskeleton. Decreased cell-cell adhesion and increased motility on laminin have been correlated with more poorly differentiated and aggressive carcinomas.
Methods: In this study, the RKO cell line, previously shown by us to lack E-cadherin expression, was transfected with the complementary DNA for E-cadherin. The transfectants were selected for high levels of surface expression by sequential FACS and examined in functional assays.
Results: In comparison to control transfectants, the E-cadherin transfectants exhibited a more epithelial-like morphology, a 30% increase in Ca(2+)-dependent cell-cell aggregation, and a markedly reduced motility on the matrix proteins, collagen I and laminin.
Conclusions: These data demonstrate that correction of a defect in the cadherin/catenin cell-cell adhesion complex, often found in poorly differentiated and highly invasive tumors, facilitates increased cell-cell adhesion and retards tumor cell migration on basement membrane and stromal proteins.