Quinazoline-sulfonamide hybrids as multitarget anticancer agents: inhibition of carbonic anhydrase IX/XII isoforms and VEGFR-2 with in vitro and in silico validation.

Dual inhibition by a single small molecule has emerged as a promising paradigm in anticancer therapy. Carbonic anhydrase isoforms IX/XII (CA IX/XII) and vascular endothelial growth factor (VEGF) are hypoxia-responsive enzymes that drive tumorigenesis and progression in hypoxic tumors through distinct mechanisms. In this study, we rationally designed and synthesized two series of 2-thioquinazolin-4-one-tethered benzenesulfonamides 7a-e, 10a-e as novel CA IX/XII and VEGFR-2 inhibitors. Lead compounds 10c and 10e exhibited potent multitarget inhibition, with IC50 values of 0.145 and 0.069 μM (VEGFR-2), 0.168 and 0.077 μM (CA IX), 0.154 and 0.205 μM (CA XII), which were comparable to those of sorafenib and acetazolamide standards. These agents demonstrated broad-spectrum cytotoxicity against HeLa, HepG2, HCT-116, and MCF-7 cell lines (IC50 = 11.57–21.43 μM for 10c; 7.81–19.50 μM for 10e). Mechanistic studies confirmed the induction of G2/M arrest by 10e, triggering 47.25% apoptosis via a sevenfold Bax/Bcl-2 upregulation and 4- to 5.7-fold caspase-3 and 9 activations, consistent with intrinsic pathway engagement. Molecular docking and dynamics simulations elucidated favorable multitarget binding conformations, thereby validating the hybrid design strategy.