TRIM21 mediates ubiquitination of Snail and modulates epithelial to mesenchymal transition in breast cancer cells.

Migration and invasion of cancer cells are greatly increased during epithelial to mesenchymal transition (EMT). Depletion of TRIM21 promotes the migration and invasion of MCF7 and T47D cells, and changes the expression of genes that regulate EMT. TRIM21 interacts with Snail, a master regulator of EMT. Overexpression of TRIM21 leads to increased ubiquitination and proteosomal degradation of Snail, while depletion of TRIM21 decreases the ubiquitination of Snail. Importantly, depletion of Snail suppresses the increased migration and invasion of MCF7 and T47D cells promoted by depletion of TRIM21. High-level expression of TRIM21 is associated with longer overall survival in breast cancer. Together, our study demonstrates that TRIM21 modulates EMT by mediating the stability of Snail in breast cancer cells.