Dual EGFR/HER2 inhibitors and apoptosis inducers: New benzo[g]quinazoline derivatives bearing benzenesulfonamide as anticancer and radiosensitizers

Dual targeting of EGFR and HER2 is a proven anticancer strategy for the treatment of solid tumors. An array of new N-substituted-2-(4-oxo-3-(4-sulfamoylphenyl)-3,4-dihydrobenzo[g]quinazolin-2-ylthio) acetamides 5-18 were designed and synthesized from the starting compound 4-(2-mercapto-4-oxobenzoW quinazolin-3(4H)-yl) benzenesulfonamide 4. The targeted compounds were screened for their cytotoxic activity against MDA-MB-231 breast cancer cell line. The IC50 of all the compounds were in the range of 0.36-40.90 mu M. The percentage inhibition towards EGFR was measured and found to be in the range of 63.00-16.90 %. The most potent compounds 5, 9, 15, 17 and 18 were further screened for their activity against both EGFR and HER2 receptors. The compounds showed IC50 in the range of 0.64-1.81 mu M for EGFR and 1.13-2.21 mu M for HER2, in comparison to erlotinib, the reference drug. Compound 17, the most potent towards EGFR in this series, undergoes cell cycle analysis and was found to arrest the cycle at the G2/M phase. Measurement of the cytotoxicity of compound 17 against normal breast cell line showed mild cytotoxic activity. The most potent compounds were subjected to a single dose of 8 Gy of gamma-radiation and the cytotoxicity of the tested compounds was found to increase after irradiation, thus proving the synergistic effect of gamma-irradiation. Molecular docking was adopted for all the synthesized compounds to confirm their mechanism of action.