Abstract: 3- (l-anilinoethylidene) -5-benzylpyrrolidine-2, 4-dione (TN16), a synthetic compound, has previously been reported to have anti tumor effect and to inhibit microtubule assembly in vitro. In this study, we found that TN16 inhibited HeLa cell proliferation by depolymerizing the cellular microtubules. HeLa cell proliferation was blocked in mitosis. The present study is consistent with earlier reports of mitosis blocking effects of TN16. By this study, we concluded that TN16 inhibited growth of HeLa cells at IC50 of 48±2 nM. The low IC50 in nanomolar range is interesting from the point of view of cancer treatment because two major anticancer drugs Vinblastine and Paclitaxel act on Hela cells in nanomolar concentrations. TN16 caused more than 30 % mitotic arrest in 200 nM concentration (4x IC50). TN16 depolymerized mitotic microtubules strongly giving rise to aberrant multipolar spindle formation at and above 50 nM concentration. The cells dying through apoptosis in presence of different concentrations of TN16 were also visualized. These data suggest that TN16 inhibited HeLa cell proliferation at mitosis by depolymerizing spindle microtubules.
Keywords: Tubulin, TN16, HeLa cell line, mitotic arrest