The development of a novel transforming growth factor-β (TGF-β) inhibitor that disrupts ligand-receptor interactions

Transforming growth factor-beta (TGF-beta) plays an important role in regulating epithelial to mesenchymal transition (EMT) and the TGF-beta signaling pathway is a potential target for therapeutic intervention in the development of many diseases, such as fibrosis and cancer. Most currently available inhibitors of TGF-beta signaling function as TGF-beta receptor I (T beta R-I) kinase inhibitors, however, such kinase inhibitors often lack specificity. In the present study, we targeted the extracellular protein binding domain of the TGF-beta receptor II (T beta R-II) to interfere with the protein-protein interactions (PPIs) between TGF-beta and its receptors. One compound, CJJ300, inhibited TGF-beta signaling by disrupting the formation of the TGF-beta-T beta R-I-T beta R-II signaling complex. Treatment of A549 cells with CJJ300 resulted in the inhibition of downstream signaling events such as the phosphorylation of key factors along the TGF-beta pathway and the induction of EMT markers. Concomitant with these effects, CJJ300 significantly inhibited cell migration. The present study describes for the first time a designed molecule that can regulate TGF-beta-induced signaling and EMT by interfering with the PPIs required for the formation of the TGF-beta signaling complex. Therefore, CJJ300 can be an important lead compound with which to study TGF-beta signaling and to design more potent TGF-beta signaling antagonists. (C) 2020 Elsevier Masson SAS. All rights reserved.