One key regulator of epithelial cell extrusion is the Hippo pathway. The Hippo pathway is a signalling cascade that is activated in response to cell-cell contact and cell density. When cell density is high, the Hippo pathway is activated, which leads to the inhibition of the transcriptional coactivator YAP1. YAP1 is a key regulator of cell growth and proliferation, and its inhibition leads to the induction of epithelial cell extrusion.
Another important regulator of epithelial cell extrusion is the Wnt signalling pathway. The Wnt signalling pathway is a crucial signalling cascade that is involved in various cellular processes, including cell proliferation, differentiation, and migration. In the context of epithelial cell extrusion, the Wnt signalling pathway has been shown to play a role in the regulation of cell adhesion and the induction of epithelial-mesenchymal transition (EMT). EMT is a process by which epithelial cells lose their epithelial characteristics and acquire mesenchymal features, which is often associated with increased cell motility and invasiveness. Activation of the Wnt signalling pathway can induce EMT and promote epithelial cell extrusion.
In addition to the Hippo and Wnt signalling pathways, several other signalling pathways and molecular mechanisms have been implicated in the regulation of epithelial cell extrusion. These include the transforming growth factor-beta (TGF-β) signalling pathway, the Notch signalling pathway, and the integrin-linked kinase (ILK) signalling pathway.
Overall, the regulation of epithelial cell extrusion is a complex process that involves multiple signalling pathways and molecular mechanisms. Dysregulation of these pathways can lead to defects in epithelial cell extrusion and the development of various diseases, including cancer. Understanding the mechanisms that regulate epithelial cell extrusion is therefore of great importance for the development of novel therapeutic strategies for these diseases.
