RESUMEN
The lineage transition between epithelium and mesenchyme is a process known as epithelial- mesenchymal transition (EMT) , by which polarized epithelial cells lose their adhesion property and obtain mesenchymal cell phenotypes.EMT is commonly found in embryonic development, wound healing, organ fibrosis and tumor metastasis.EMT and mesenchymal-epithelial transition (MET) are involved in the early and late development of embryo, such as implantation, gastrulation, heart development and so on.EMT and MET are involved in the regulation of stem cell phenotype changes and cell migration, which are important mechanisms of cell differentiation and three-dimensional tissue construction.The expression of cell adhesion molecules is transformed from E-cadherin to N-cadherin, which is an important sign of EMT.By interacting with (3-catenin, p 120-catenin and a-catenin, E-cadherin can affect the activation of Wnt, small GTPase superfamily and other signaling pathways and regulate cytoskeleton movement.TGF, Notch, Wnt, BMP, FGF, and other signaling pathways, Snail, Twist, Zeb and other transcription factors, together with epigenetic modifying enzymes, participate in the initiation and regulation of EMT in a coordinated way.In vitro models showed that E-cadherin was involved in self-renewal of stem cells.Somatic cell reprogramming could he regarded as MET, and the expression of E- cadherin can he obtained in somatic cells after transfection of reprogramming factors.In vitro studies have found that EMT and its related molecules (such as E-eadherin, Snail, Twist, Zeb, etc.) were involved in the early triploblast differentiation and the formation of specific cell types in the late stage.The study on the mechanism of EMT will help to improve the differentiation efficiency of stem cells in vitro and promote the induction of organoids.