Synthesis, biological evaluation and molecular docking studies of trans-indole-3-acrylamide derivatives, a new class of tubulin polymerization inhibitors.

In this study, we synthesized a series of trans-indole-3-acrylamide derivatives (3a-k) and investigated their activity for inhibition of cell proliferation against five human cancer cell lines (HeLa, MCF7, MDA-MB-231, Raji and HL-60) by MTT assay. Compound 3e showed significant antiproliferative activity against both the Raji and HL-60 cell lines with IC50 values of 9.5 and 5.1 μM, respectively. Compound 3e also exhibited moderate inhibitory activity on tubulin polymerization (IC50=17 μM). Flow cytometric analysis of cultured cells treated with 3e also demonstrated that the compound caused cell cycle arrest at the G2/M phase in HL-60 and HeLa cells. Moreover, 3e, the most active compound, caused an apoptotic cell death through the activation of caspase-3. Docking simulations suggested that 3e binds to the colchicine site of tubulin.