Design, synthesis, and biological evaluation of quinazoline-benzohydrazide and quinazoline-benzothiazole hybrids uncovering a dual EGFR/VEGFR-2 inhibitor with pronounced cytotoxic activity against triple-negative breast Cancer.

Novel series of quinazoline-benzohydrazide 7a-f and quinazoline-benzothiazole 10a-f hybrids were designed and synthesized as potential dual-target inhibitors of EGFR and VEGFR-2. Their anti-proliferative activity was assessed against HeLa, HepG2, MCF-7 and HCT116 cancer cell lines. Among the tested compounds, 7a demonstrated the most potent activity, with IC₅₀ values ranging from 3.98 to 9.67 μM, comparable with doxorubicin. Most derivatives showed minimal cytotoxicity toward normal WI-38 fibroblasts, indicating a favorable selectivity profile. Notably, compound 7a exerted significant cytotoxic effect against triple-negative breast cancer (TNBC) MDA-MB-231 cells (IC₅₀ = 7.33 μM), approaching the activity of doxorubicin (IC₅₀ = 2.22 μM). It also markedly inhibited EGFR and VEGFR-2 with IC₅₀ values of 1.67 and 6.72 μM, compared to Erlotinib and Sorafenib, respectively. Flow cytometric analysis revealed that 7a induced cell cycle arrest at the G0/G1 phase (85.11 %) and promoted apoptosis (29.49 %). Apoptotic profiling further indicated a substantial upregulation of pro-apoptotic Bax (11.73-fold) and downregulation of anti-apoptotic Bcl-2 (0.23-fold), resulting in a striking increase in the Bax/Bcl-2 ratio (51:1). Additionally, 7a increased the expression levels of caspase-3 and caspase-9 by approximately 7.55- and 5.76-fold, respectively, compared to control/ MDA-MB-231 cells. Molecular docking studies confirmed the strong binding affinity of 7a within the active sites of both EGFR and VEGFR-2, supporting its proposed mechanism of action. These findings position compound 7a as a promising lead for further development as a dual EGFR/VEGFR-2-targeting anticancer agent, particularly for aggressive cancers such as TNBC.