Design, synthesis, and characterization of novel 5-ethylsulfonyl-indazole-3-carboxamides as dual VEGFR-2 and EGFR inhibitors: apoptotic antiproliferative and immunomodulatory evaluations

Abstract

This study focused on the design and synthesis of a novel series of 5-ethylsulfonyl-indazole-3-carboxamides (8a–l) as dual inhibitors of VEGFR-2 and EGFR. Compounds 8g and 8h emerged as the most efficient derivatives among all evaluated compounds against breast (MCF-7) and colorectal (HCT-116) cancer cell lines, exhibiting IC₅₀ values of 24 and 28 nM for HCT-116 and MCF-7 cell lines, respectively, for 8g, and 23 and 25 nM for the same cell lines for 8h. Compounds 8g and 8h exhibited a promising safety margin against normal cells (WI-38) (IC₅₀ values > 150 nM). In vitro enzyme assays demonstrated that compounds 8g and 8h exhibited potent inhibition of VEGFR-2 and EGFR. Furthermore, compounds 8g and 8h induced apoptosis by activating Bax, p53, caspase-3, 8, and 9, as well as down-regulating Bcl-2. Compounds 8g and 8h reduced TNF-α and IL-6 levels compared to dexamethasone. The computational investigation of compound 8h, a novel indazole-based urea derivative, was undertaken to rationalize its potent dual inhibition of EGFR and VEGFR-2. Molecular docking studies revealed a high binding affinity and a favorable interaction profile with key kinase residues, particularly hinge-region contacts with Met769 (EGFR) and Glu885/Asp1046 (VEGFR-2). Follow-up molecular dynamics (MD) simulations confirmed the stability of the 8h–EGFR complex over 150 ns, characterized by persistent hydrogen bonding, low RMSF in the binding site, and consistent radius of gyration. Quantum mechanical (QM) analyses, including DFT and MEP mapping, revealed a HOMO–LUMO gap of 4.55 eV, high dipole moment (9.3 D), and distinct electron-rich/hydrogen-bonding regions, supporting strong molecular interactions. Additionally, SwissADME profiling demonstrated acceptable drug-likeness, moderate solubility, and a low CYP-inhibition profile, suggesting favorable pharmacokinetics compared to the reference inhibitor erlotinib. These integrated computational findings align with experimental data on antiproliferative effects and kinase inhibition, reinforcing compound 8h as a promising dual-target anticancer candidate.