Methyl 5-[(1H-indol-3-yl)selanyl]-1H-benzoimidazol-2-ylcarbamate (M-24), a novel tubulin inhibitor, causes G2/M arrest and cell apoptosis by disrupting tubulin polymerization in human cervical and breast cancer cells.

Methyl 5-[(1H-indol-3-yl)selanyl]-1H-benzoimidazol-2-ylcarbamate (M-24) is a newly synthesized analogue of nocodazole by our group and has been found to be active for some cancer cells. However, its sensitivity to different cell lines and the underlying anticancer mechanism are still unclear. In this study, we proved that M-24 had strong time- and dose-dependent anti-proliferative effects on human cervical cancer HeLa cells and human breast carcinoma MCF-7 cells. We demonstrated that the growth inhibitory effects of M-24 in both cell lines were associated with microtubule depolymerization. Furthermore, M-24 treatment resulted in cell cycle arrest at the G2/M phase in a dose-dependent manner with subsequent apoptosis induction. Western blotting analysis revealed that up-regulation of cyclin B1 and cdc2 was related with G2/M arrest in both cell lines. In addition, M-24-induced HeLa cell apoptosis was mainly associated with mitochondria-dependent intrinsic pathway. However, M-24-induced MCF-7 cell apoptosis was associated with both mitochondrial and death receptor pathway. In conclusion, M-24 caused apoptosis through disrupting microtubule assembly and inducing cell cycle arrest in HeLa and MCF-7 cells. Therefore, the novel compound M-24 is a promising microtubule-destabilizing agent that has great potential for the therapy of various malignancies especially human cervical and breast cancers.

Novel hybrid nocodazole analogues as tubulin polymerization inhibitors and their antiproliferative activity.

We describe the design, synthesis and SAR profiling of a series of novel combretastatin-nocodazole conjugates as potential anticancer agents. The thiophene ring in the nocodazole moiety was replaced by a substituted phenyl ring from the combretastatin moiety to design novel hybrid analogues. The hydroxyl group at the ortho position in compounds 2, 3 and 4 was used as the conformationally locking tool by anticipated six-membered hydrogen bonding. The bioactivity profiles of all compounds as tubulin polymerization inhibitors and as antiproliferative agents against the A-549 human lung cancer cell line were investigated Compounds 1 and 4 showed µM IC50 values in both assays.