Exploration of N-alkyl-2-[(4-oxo-3-(4-sulfamoylphenyl)-3,4-dihydroquinazolin-2-yl)thio]acetamide derivatives as anticancer and radiosensitizing agents.

Multitargeted therapy is considered a successful approach to cancer treatment. The development of small molecule multikinase inhibitors through hybridization strategy can provide highly potent and selective anticancer agents. A library of N-alkyl-2-[(4-oxo-3-(4-sulfamoylphenyl)-3,4-dihydroquinazolin-2-yl)thio]acetamide derivatives 5-18 was designed and synthesized. The synthesized compounds were screened for cytotoxic activity against MDA-MB-231 breast cancer cell line and showed IC50 in the range of 0.34-149.10 µM. The inhibition percentage of VEGFR-2 was measured for all the compounds and found to be in the range of 90.09-20.44%. The promising compounds 8, 12, 13, 16 and 17 were selected to measure their possible multikinase inhibitory activity against VEGFR-2 and EGFR. IC50 of the promising compounds were in the range of 247-793 nM for VEGFR-2 in reference to sunitinib (IC50 320 nM), and 369-725 nM for EGFR in reference to erlotinib (IC50 568 nM). Compounds 12 and 13 showed the most potent activity towards VEGFR-2 & EGFR, respectively. Measuring the cytotoxicity of 12 and 13 against MCF-10 normal breast cell line indicates their relative safety to normal breast cells (IC50 37 & 97 µM, respectively). As radiotherapy is considered the primary treatment for some types of solid tumors, the radiosensitizing ability of 12 and 13 was measured by subjecting the MDA-MB-231 cells to a single dose of 8 Gy of gamma radiation. IC50 of 12 and 13 decreased from 1.91 & 0.51 µM to 0.79 & 0.43 µM, respectively. Molecular docking was performed to gain insights into the ligand-binding interactions of 12 inside VEGFR-2 and EGFR binding sites in comparison to their co-crystallized ligands.