Serpine1 functions as a non-coding RNA regulating post-transcriptionally epithelial mesenchymal transition [iCLIP]

Serpine1 mRNA is abundantly induced during EMT. Paradoxically, this mRNA is enriched in the RISC complex, blocking its translation and acting as an endogenous RNA competitor for several miRNAs. Cells that overexpress Serpine1 mRNA have a greater capacity for migration, invasiveness, and resistance to anoikis. These cells show an altered proteomic profile, highlighting the increased levels of expression of the splicing factor TRA2b. This splicing factor is posttranscriptionally regulated during EMT by upregulation of Serpine1 mRNA and the resulting sequestration of miR-130b-5p by this mRNA, which contains three binding sites for miR-130b-5p. Through transcriptomic analysis, we confirmed that Serpin 1 mRNA expression modulates the expression of numerous genes, most of which (>60%) are also modulated by TRA2b overexpression. Overall design: iCLIP, NMuMG mouse glandular epithelial cells treated with TGFb for 4h or 48h, in triplicates.