New Thiadiazole-Benzenesulfonamide Hybrids as Dual B-Raf/VEGFR-2 Inhibitors With Promising Anti-Hepatic Cancer Activity

Abstract

A new group of thiadiazole-benzenesulfonamide hybrids was designed, synthesized, and biologically evaluated as potential dual inhibitors targeting B-Raf and VEGFR-2 for cancer therapy. The cytotoxic activity of the synthesized derivatives was assessed against HepG2 and Huh7 liver cancer cell lines, where compound 7a exhibited the most potent activity with IC₅₀ values of 17.89 μM and 25.07 μM, respectively. The kinase inhibition assay revealed that 7a strongly inhibited both B-Raf (IC₅₀ = 0.11 μM) and VEGFR-2 (IC₅₀ = 0.15 μM), surpassing sorafenib in B-Raf inhibition. Further mechanistic studies revealed that 7a induced G2/M phase arrest, with a significant increase in late apoptotic cells (57.08%) compared to the control group (0.15%), confirming its pro-apoptotic effect. The apoptotic pathway was further validated by caspase-3 activation, Bax upregulation, and Bcl-2 downregulation. Computational analyses verified the effective binding of compound 7a to VEGFR-2. These analyses included molecular docking, molecular dynamic (MD) simulations, molecular mechanics with generalized Born and surface area solvation (MM-GBSA), protein-ligand interaction fingerprints (ProLIF), principal component analysis (PCAT), and free energy landscape (FEL) studies. Additionally, DFT studies indicated 7a's stability and reactivity. In silico ADMET predictions indicated that the derivatives had good absorption, were non-mutagenic, non-carcinogenic, and exhibited low toxicity risks compared to sorafenib. These findings suggest that the synthesized thiadiazole-benzenesulfonamide hybrids, particularly 7a, represent promising dual BRAF/VEGFR-2 inhibitors with potent anti-cancer activity, warranting further optimization and preclinical evaluation.