Differences in Adhesion of Urothelial Cells to a Panel of Substrates Are Characteristic for Established Human Urothelial Cell Lines Differing in Their Transformation Grade

Eight human urothelial cell lines established and propagated in the Fibiger Institute, differing in their transformation grade as described by Christensen et al were brought into suspension and contacted with a panel of seven substrates, ie. Con. A, Fibronectin, WGA, Collagen IV, Laminin, PNA and artificial basal membrane. Cell adhesion was measured on big cell populations with the use of flow cytophotometry, measured samples contained nonadhering cells and fluorescent beads, added as an internal standard. It was found that the cell lines differed from each other by the kinetics of cell adhesion to the chosen panel. A higher percentage of cells belonging to established cell lines adhered to PNA, WGA or Con A coated surfaces than to laminin, fibronectin or collagen IV. The difference in adherence of cells to fibronectin, laminin or collagen IV coated surfaces makes differentiation between the single cell lines possible. Discriminant analysis of the total patterns of adhesion of all cell lines was used for comparison. The effect of trypsinization on the structure of the cell surface, accompanied by possible changes in adherence, was evaluated by comparison of the immediate results with those obtained with cells after 3 hours of recovery at 37 degrees C. It was found that all cell lines showed a better adherence to laminin after recovery. This is consistent with the published data on the high sensitivity of laminin receptors to trypsinization. On the other hand, the receptors for PNA, WGA and Con A were less expressed after the recovery period, as evidenced by a decreased adherence of the cells to these three substrates. The effect of recovery of cells on the amount of their receptors for fibronectin and collagen IV was different in different cell lines, but the direction of change for this pair of receptors was identical in a given cell line. In some instances the recovery period had no effect whatsoever on cell adherence. The different pattern of adhesion of cells belonging to established cell lines to the chosen panel of substrates can be used as a parameter for characterization of single cell lines, but it does not correlate with their grade of transformation.