Design and Synthesis of Sorafenib-Inspired Benzofuran Hybrids as VEGFR-2 Inhibitors: Antiproliferative Evaluation, Mechanistic Insights, and Docking Studies in Hepatocellular Carcinoma

Abstract

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide owing to its high metastatic potential. Vascular endothelial growth factor receptor-2 (VEGFR-2), a key regulator of angiogenesis and cell proliferation, is a critical therapeutic target in cancer, particularly in HCC. However, the clinical use of various VEGFR-2 inhibitors is limited by adverse effects, poor selectivity, and drug resistance. In this study, two novel series of sorafenib-inspired benzofuran hybrids, azines (6a–k) and thiosemicarbazones (7a–g), were synthesized and evaluated for their cytotoxicity against HepG-2 cell lines. Compounds 6b, 6c, 7a, 7b, 7e, 7f, and 7g exhibited potent activity with IC₅₀ values of 7.21–18.01 µM. Among them, 7a, 7b, 7f, and 7g demonstrated high selectivity (SI= 5.7–11.2) toward HepG-2 cells over normal WI-38 cells. Enzyme assays confirmed significant VEGFR-2 inhibition, led by 7g (IC₅₀ = 0.072 µM), comparable to sorafenib (IC₅₀ = 0.069 µM). In HepG-2 cells, 7g induced G0/G1 arrest and apoptosis, upregulating Bax, caspase-8 and -9, and downregulating Bcl-2. Molecular docking confirmed the strong binding affinity of 7g within the VEGFR-2 active site through key interactions with Glu885, Asp1046, and Cys1045, mirroring sorafenib. A 100-ns molecular dynamics simulation further demonstrated that compound 7g retains a highly stable binding mode within VEGFR-2, supported by low RMSD fluctuations and persistent key hydrogen-bond and hydrophobic interactions. These findings nominate 7g as a promising VEGFR-2-targeted lead for HCC upon further optimization.