Design, synthesis, and anti-prostate cancer activity evaluation of novel thieno[2,3-b]pyridine derivatives as potential BLM helicase inhibitors
摘要
Herein, twenty-four novel thieno[2,3-b]pyridine derivatives were rationally designed and synthesized based on a versatile key intermediate. All compounds were evaluated for in vitro antiproliferative activity against PC3 and VCaP prostate cancer cell lines using the MTT assay, and most exhibited good antitumor potency. Compound 9v showed the strongest activity, with IC50 values of 0.49 μM (PC3) and 0.85 μM (VCaP). Mechanistic studies revealed that 9v concentration-dependently induced apoptosis and G0/G1 cell cycle arrest, and suppressed PCa cell migration and invasion in both time- and concentration-dependent manners. Further target validation showed that 9v efficiently inhibited BLM helicase-mediated DNA unwinding with an IC50 of 3.17 μM, outperforming the lead compound TC1. Combined MST and BLI assays verified that 9v exhibited higher binding affinity toward BLM protein than the lead compound TC1 and preferentially interacted with BLM instead of its DNA substrate. Mechanistically, 9v competitively interfered with BLM-DNA substrate interaction to block BLM DNA unwinding function. Molecular docking revealed that 9v stably bound to key amino acid residues in the BLM RQC domain, consistent with the binding characteristics of reported BLM inhibitors. In conclusion, 9v displays superior antiproliferative and BLM helicase inhibitory activities compared with TC1, representing a promising lead compound for the development of novel BLM-targeted anti-prostate cancer agents.