Cell-to-substrate adhesions during spreading and locomotion of carcinoma cells : A study by microcinematography and reflection contrast microscopy

Motility and patterns of adhesion were determined by time-lapse cinematography and reflection contrast microscopy for two types of carcinoma cells, selected for their different motile behavior and not for their malignancy. Cells from the V2 rabbit carcinoma become locomotory soon after having established the necessary contact to the substratum. In contrast, cells from a human epidermoid carcinoma (LICR-OC-1) first attain a fully spread configuration before some cells slightly round up again for a slow locomotory activity of short range and duration. Reflection contrast showed that during spreading and locomotion, the cells from both carcinomas displayed a predominance of grey, the color associated with close contacts. Fully spread cells, on the other hand, presented a multitude of focal contacts in individually different arrangements of black streaks and dots, randomly distributed over the entire cell area. The functional meaning of this heterogeneity in the arrangement of focal contacts in fully spread cells is not yet understood. The importance of close contacts for spreading and locomotion, however, seems to be established and is in agreement with findings reported for other cell types engaged in the same activities. It is therefore suggested that the formation of substrate contacts depends on cellular activity rather than on the cell type.