Directional-to-Random Transition of Cell Cluster Migration

Efficient cell migration is crucial for the functioning of biological processes, e.g., morphogenesis, wound healing, and cancer metastasis. In this study, we monitored the migratory behavior of 3D fibroblast clusters using live cell microscopy, and found that crowded environment affects cell migration, i.e., crowding leads to directional migration at the cluster's periphery. The number of cell layers being stacked during seeding determines the directional-to-random transition. Intriguingly, the migratory behavior of cell clusters resembles the dispersion dynamics of clouds of passive particles, indicating that the biological process is driven by physical effects (e.g., entropy) rather than cell communication. Our findings highlight the role of intrinsic physical characteristics, such as crowding, in regulating biological behavior, and suggest new therapeutic approaches targeting at cancer metastasis.