Molecular signaling of the epithelial to mesenchymal transition in generating and maintaining cancer stem cells.

The epithelial to mesenchymal transition (EMT) is a highly conserved cellular program that allows polarized, well-differentiated epithelial cells to convert to unpolarized, motile mesenchymal cells. EMT is critical for appropriate embryogenesis and plays a crucial role in tumorigenesis and cancer progression. Recent studies revealed that there is a direct link between the EMT program and the gain of epithelial stem cell properties. EMT is sufficient to induce a population with stem cell characteristics from well-differentiated epithelial cells and cancer cells. In this review, we briefly introduce the biology of EMT inducers and transcription factors in tumorigenesis and then focus on the role of these key players of the EMT in generating and maintaining cancer stem cells.