Design, synthesis and biological evaluation of 4-anilinoquinoline derivatives as novel potent tubulin depolymerization agents.

A series of novel 4-anilinoquinoline derivatives were synthesized and evaluated for their antiproliferative activities. Among them, 14h exhibited the most potent cytotoxic activity with IC50 values ranging from 1.5 to 3.9 nM against all tested cancer cell lines, and showed promising efficacy in multidrug resistant cancer cells. Flow cytometry assay, immune-fluorescence staining, microtubule dynamics assays and competition assays with EBI identified that 14h was a novel tubulin depolymerization agent by binding to the colchicine site. Importantly, in vivo efficacy evaluation of HCT116 xenograft model, 14h showed efficient antitumor activity without significant loss in body weight. All the results indicated that 14h could be a promising candidate for the treatment of cancer.