Before revision: We theoretically investigate the mechanical stability of three-dimensional (3D ) foam geometry in a cell sheet and apply its understandings to epithelial integrity and cell delamination.
After revision: In cell extrusion, a cell embedded in an epithelial monolayer loses its apical or basal surface and is subsequently squeezed out of the monolayer by neighboring cells. Cell extrusions occur during apoptosis, epithelial-mesenchymal transition, or pre-cancerous cell invasion. They play important roles in embryogenesis, homeostasis, carcinogenesis, and many other biological processes. Although many of the molecular factors involved in cell extrusion are known, little is known about the mechanical basis of cell extrusion. We used a three-dimensional (3D ) foam geometry in a cell sheet and apply its understandings to epithelial integrity and cell delamination.