To gain insights into how TGF-β regulates epithelial-mesenchymal transition (EMT), we assessed the time course of proteins and mRNAs during EMT by multiplex iTRAQ labeling and 2D-LC-MS/MS, and by hybridization, respectively. Temporal iTRAQ analysis identified 66 proteins as differentially expressed during EMT, including newly associated proteins calpain, fascin and macrophage-migration inhibitory factor (MIF). Comparing protein and mRNA expression overtime showed that all the 14 up-regulated proteins involved in the actin-cytoskeleton remodeling were accompanied by increases in corresponding mRNA expression. Interestingly, siRNA mediated knockdown of cofilinl potentiated TGFβ-induced EMT. Further analysis of cofilinl and β-actin revealed an increase in their mRNA stability in response to TGF-β, contributing to the observed increase in mRNA and protein expression. These results are the first demonstration of post-transcriptional regulation of cytoskeletal remodelling and a key role for cofilinl during TGF-β-induced EMT.
- Actin-cytoskeleton remodeling
- Epithelial-mesenchymal transition
- Lung cancer
- Qualitative proteomics