A SIMPLE FLUOROMETRIC ASSAY FOR QUANTIFYING THE ADHESION OF TUMOR-CELLS TO ENDOTHELIAL MONOLAYERS

A static adhesion assay employing 6-carboxy-3',6'-diacetylfluorescein (6-CFDA) as a fluorescent marker has been developed to study the inter actions of tumour cell lines with endothelial monolayers. This assay a llows simple, safe quantification of cell-cell adhesion using living c ells. It has been used to demonstrate that the integrin adhesion molec ule VLA-4 mediates the attachment of RPMI-7951 melanoma cells to human umbilical vein endothelial cells (HUVEC) which have been activated by TNF alpha. In addition, MDA-MB-231 breast adenocarcinoma cells displa y greater adhesion to microvessel endothelial cells than to large vess el endothelial cells.