Anthraquinone Derivatives as Potent Inhibitors of c-Met Kinase and the Extracellular Signaling Pathway.

The aberrant function of c-Met kinase signaling pathway is ubiquitously involved in a broad spectrum of human cancers; thus, a strong rationale exists for targeting the kinase pathway in cancer therapy. Via integration of computational and experimental studies, anthraquinone derivatives were identified for the first time as potent c-Met kinase inhibitors in this research. The aberrant activation of the c-Met kinase pathway results from (TPR)-Met, MET gene mutation, or amplification and a hepatocyte growth factor (HGF)/scatter factor-dependent autocrine or paracrine mechanism. However, anthraquinone derivatives exclusively suppressed c-Met phosphorylation stimulated by HGF in A549 cells, indicating that the compounds possess the ability to block the extracellular HGF-dependent pathway. A surface plasmon resonance assay revealed that the most potent compound, 2a, shows a high binding affinity for HGF with an equilibrium dissociation constant of 1.95 μM. The dual roles of compound 2a demonstrate the potency of anthraquinone derivatives and provide a new design solution for the c-Met kinase signaling pathway.