Design and bio-evaluation of novel millepachine derivatives targeting tubulin colchicine binding site for treatment of osteosarcoma

Microtubules are recognized as an appealing target for cancer treatment. We designed and synthesized of novel tubulin colchicine binding site inhibitors based on millepachine. Biological evaluation revealed compound 5h exhibited significant antiproliferative activity against osteosarcoma cell U2OS and MG-63. And compound 5h also remarkably inhibited tubulin polymerization. Further investigations indicated compound 5h not only arrest U2OS cells cycle at the G2/M phases, but also induced U2OS cells apoptosis in dose-dependent manners. Moreover, compound 5h was verified to inhibit cell migration and angiogenesis of HUVECs, induce mitochondrial membrane potential decreased and promoted the elevation of ROS levels. Furthermore, compound 5h exhibited remarkable effects on tumor growth in vivo, and the TGI rate was up to 84.94 % at a dose of 20 mg/kg without obvious toxicity. These results indicated that 5h may be an appealing tubulin inhibitor for treatment of osteosarcoma.