The relation between the collective motility and shapes of human cancer cells under heat stress

Abstract

Epithelial tumor cells may display different collective invasion behaviors, forming an unjammed flow like a fluid or a jammed deformation like a solid depending on such factors as cell–cell adhesion, cell–substrate adhesion, or the density and shapes of the cells. We investigate the relation between the collective motility and the shapes of human cancer cells under heat stress. The collective dynamics of MGC-803 cells in a confluent monolayer subjected to heat stress at 48 °C for 10 min were observed and analyzed using the long-term live imaging technique. We found that the normal cell motions slow down with increasing cell density and cell–cell adhesion, accompanied by a decrease in the average aspect ratio of the cell shapes and substrate-to-cell traction. Heat stress can speed up cellular motions while almost maintaining the same cell density and cell–cell adhesion and also increases the cell shape index and the traction force exerted by the cells on the substrate. An approximately linear relation is revealed between the collective migration velocity and the shape index of the heated cells. This work helps explain the collective motility of cancer cells and provides inspiration for regulating cell motion with factors such as temperature.