Antitumor Activity of Tetrahydro-β-carboline Derivatives via Inhibition of Kinesin Spindle Protein: Validation by Molecular Docking, Molecular Dynamics, and In Vitro Assays.

The tetrahydro-β-carboline heterocycle is a privileged scaffold found in numerous natural products and bioactive drugs, demonstrating significant potential for cancer therapy. In this study, we designed and synthesized novel tetrahydro-β-carboline derivatives (-) based on this core structure and evaluated their anticancer activity against human lung cancer (A549). Among them, compounds and exhibited potent cytotoxicity against A549 cells, effectively suppressing cell migration and colony formation. Mechanistic studies revealed that these compounds promoted apoptosis by upregulating pro-apoptotic Bax, downregulating anti-apoptotic Bcl-2, and activating caspase proteins. Molecular docking and dynamics simulations demonstrated that compounds and form stable complexes with the Eg5 protein through multiple hydrogen bonds, which was further validated by thermal shift assays. Collectively, these findings indicate that compounds and induce apoptosis in A549 cells by selectively targeting and stabilizing Eg5, highlighting their potential as lead candidates for lung cancer therapy.