Tumor lethality largely depends on transformations that lead tumor cells to invade neighboring tissues. Invasion can occur either by isolated cells or by aggregates that migrate collectively. Collective migration is presently suspected to confer a selective advantage to migrating cells. The study of three-dimensional cancer cell cultures shows migrating cells eventually aggregating in large clusters. Quantitative measurements of cluster velocity, coalescence rates, and proliferation rates suggest that such aggregation is not random, but driven by the exchange of diffusible attractant factors (chemotaxis). These results suggest an important role for chemotactic-driven aggregation in the spreading and survival of tumor cells.

[Sci. Rep. 5:15205, 2015]