Enhanced Anticancer Activity of 7MeERT over Ertredin: A Comparative Study on Cancer Cell Proliferation and NDUFA12 Binding

We have previously identified Ertredin (3-(2-amino-5-bromophenyl) quinoxalin-2(1H)-one) as a compound that suppresses 3D spheroid formation and tumorigenesis in NIH3T3 cells induced by <i>Epidermal Growth Factor Receptor</i> variant III (<i>EGFRvIII</i>) transduction. One of its targets has been shown to be NDUFA12 (NADH Dehydrogenase (Ubiquinone) 1 Alpha Subcomplex Subunit 12), a component protein of oxidative phosphorylation complex I. In this report, we compared the growth inhibitory activity of Ertredin with its methylated analogue 7MeERT (3-(2-amino-5-bromophenyl)-7-methylquinoxalin-2(1H)-one) on human cancer cells. 7MeERT induced the inhibition of the proliferation of various cancer cells similarly to Ertredin and showed higher activity in glioblastoma cells, A431 cells overexpressing <i>EGFR</i> (wild type), and multiple myeloma cells. Molecular docking analysis and a Cellular Thermal Shift Assay (CETSA) suggested that 7MeERT binds to NDUFA12 similarly to Ertredin. The binding of 7MeERT and Ertredin to NDUFA12 in glioblastoma was further supported by the inhibition of the oxygen consumption rate. These results suggest that 7MeERT also binds to NDUFA12, inhibits oxidative phosphorylation, and has a higher anti-cancer cell growth inhibitory activity than Ertredin.