N-Hydroxycinnamide derivatives of osthole inhibit cell migration and invasion by suppressing Smad2 and Akt pathways in human colorectal adenocarcinoma cells

WJ1376-1 and WJ1398-1 are new synthetic compounds developed based on the structure of the Chinese herbal medicine osthole. Previously, we reported that WJ1376-1 and WJ1398-1 can induce cell-cycle arrest by activating ATR kinase (ataxia telangiectasia and rad3 related kinase) and inhibiting the phosphorylation of Aurora A kinase. In this study, we determined that WJ1376-1 and WJ1398-1 strongly inhibited the migration and invasion in human colorectal cancer cells at concentrations as low as 1 μM. In the transforming growth factor (TGF)-β-induced epithelial-mesenchymal transition model, WJ1376-1 and WJ1398-1 potently downregulated the transcription factor Snail1, the mesenchymal protein vimentin, and matrix metalloprotease-9, but upregulated the epithelial protein E-cadherin. WJ1376-1 and WJ1398-1 also inhibited the TGF-β-induced phosphorylation of Smad2 and of Akt at Ser 473, and the nuclear translocation of Smad2 was substantially lower in WJ1376-1- and WJ1398-1-treated cells than it was in control cells. In transient transfection experiments, we observed that WJ1376-1 and WJ1398-1 strongly inhibited TGF-β-stimulated activity of a Smad reporter. Finally, WJ1376-1 and WJ1398-1 blocked TGF-β-induced phosphorylation of the TGF-β Type I receptor (TGF-βRI). These results suggest that WJ1376-1 and WJ1398-1 inhibit cell migration and invasion by suppressing TGF-βRI phosphorylation and subsequently hindering both Smad2 and phosphatidylinositol 3-kinase/Akt signaling pathways.