Reciprocal regulatory circuits coordinating EMT plasticity

Epithelial to mesenchymal transition (EMT) as well as its reversal process, mesenchymal to epithelial transition (MET), are essential and well-controlled cellular processes during embryonic development. Tightly controlled regulatory mechanisms guide an EMT/MET plasticity and enable cells to switch forth and back between different cell morphologies and functional capabilities to endow the necessity of tissue plasticity. However, aberrant and uncontrolled activation of these processes during malignant tumor progression promotes primary tumor cell invasion, cancer cell dissemination and metastatic outgrowth. In a recent study (Nat Commun; doi: 10.1038/s41467-017-01197-w), we have reported on the post-transcriptional control of normal and cancer-associated EMT by miRNAs and identified a novel, critical double-negative feedback regulation of the thus far unknown miRNA miR1199 and the key EMT transcription factor Zeb1.