DPYSL2 and DPYSL3 as potential regulators of EMT

The epithelial-mesenchymal transition (EMT) is a cellular program by which carcinomas acquire high-grade characteristics, resulting in the tumor ability to detach from the primary site and to metastasize. Previous studies identified the critical role of a distinct set of transcription factors as well as adhesion molecules in the proper execution of this program. However, the execution of this program is quite rare, suggesting a tight, still unknown, regulatory mechanism. Recently, our lab developed a large-scale gene expression web-based analysis tool called MERAV (Metabolic gEne RApid Visualizer) [http://merav.wi.mit.edu]. Via MERAV, we identified a set of genes that are significantly elevated in mesenchymal cells, among them are two members of dihydropyrimidinase-like (DPYSL) family, DPYSL2 and DPYSL3. These proteins, also known as Collapsin Response Mediator Proteins 2 and 4 (CRMPs 2 and 4), play a vital role in axon guidance during neural development. Here, we assess the role of CRMP2 and CRMP4 as regulators of cancer cell aggressiveness. We demonstrate that the expression of both proteins is EMT-depended and DPYSL3 knockdown inhibits the ability of cells to execute this program. Proteomics-based analysis, using CRMP2 as bait, identified an EMT-dependent complex composed of CRMP4, CRMP1, CRMP5, and other proteins. Moreover, this analysis identified specific EMT-dependent phosphorylation pattern in both CRMP2 and 4. Together, this study will reveal unknown cellular machinery that regulates the EMT program, and can potentially lay the groundwork for a new class of anti-cancer drugs that will inhibit tumor cells progression to high-grade malignancies.