7-Diethylamino-3(2`-benzoxazolyl)-coumarin is a novel microtubule inhibitor with antimitotic activity in multidrug resistant cancer cells.

Abstract

Microtubules are a proven target for anticancer drug development because they are critical for mitotic spindle formation and the separation of chromosomes at mitosis. We here report a novel synthetic microtubule inhibitor 7-diethylamino-3(2′-benzoxazolyl)-coumarin (DBC). DBC causes destabilization of microtubules, leading to a cell cycle arrest at G2/M stage. In addition, human cancer cells are more sensitive to DBC (IC50 44.8–475.2 nM) than human normal fibroblast (IC50 7.9 μM), and DBC induces apoptotic cell death of cancer cells. Furthermore, our data show that DBC is a poor substrate of drug efflux pumps and effective against multidrug resistant (MDR) cancer cells. Taken together, these results describe a novel pharmacological property of DBC as a microtubule inhibitor, which may make it an attractive new agent for treatment of MDR cancer.