Discovery of a novel inhibitory mechanism of kaempferol on TGF-β ligand-receptor interaction by single-molecule techniques

Using two single-molecule techniques, single-molecule force measurement and fluorescence imaging, we have found that a natural compound, kaempferol, exerts an inhibitory effect on TGF-β ligand-receptor binding, the initial step of TGF-β signaling.Kaempferol interferes with ligand-receptor interactions, thus blocking dimerization of its specific receptor TβRII. Furthermore, we demonstrate that kaempferol inhibits the phosphorylation of Smad2, a down-stream target of the TGF-β pathway. In addition this compound also suppresses TGF-β1-induced cancer cell migration and invasion.These results indicate a potential future application for kaempferol as a TGF-β inhibitor in cancer therapy.EIPubMed23673