Novel forms of epithelial cell motility on collagen and on glass surfaces

The motility of an epithelial cell line NBT-II derived from a rat bladder tumor was examined on glass and on collagen. On glass the cells rotate in groups of 2-8 cells. Rotatory migration ceases as cells enter into mitosis; after mitosis, the daughter cells spread out and participate in the rotatory activity of the group. As the number of cells in a group increases the rate of rotatory migration slows, and groups with ten cells or more do not rotate consistently. On collagen NBT-II cells migrate as single cells in a smooth gliding fashion, with the broad lamellipodia as the leading front. After mitosis, the two daughter cells separate at 180 degrees of each other and migrate away independently. Before totally spreading out on the collagen surface, the pair of daughter cells shows a characteristic twist of about 60 degrees from their original position at telophase. The difference in motility of NBT II cells on glass and on collagen is explained in terms of differences in cell-to-cell cohesion and cell-to-substrate adhesion.