Live Cell Extrusion in Cervical Cancer—A Novel Mechanism for Cancer Progression

Extrusion during development or of transformed cells in normal epithelia has been described as a process of elimination. However, the role of extrusion in transformed epithelia is still unclear. Here, we report that in a primary tumor-derived cervical cancer cell line, SiHa, overcrowding results in the extrusion of a subset of cells. We find that the mechanism of extrusion in SiHa cells is similar to those that drive live cell extrusion in normal epithelia, suggesting the utility of this model. We propose that the subset that is extruded during overcrowding is resistant to anoikis and acquires promigratory features. We find that this population also exhibits an increase in TGF-β signaling, which we show is a promigratory factor in cervical cancer cells and is a potential driver for the migratory potential observed in the extruded population. Our study shows that extrusion in cervical cancers in response to overcrowding underlies promigratory behavior of sub-populations in cervical cancer cell lines.