Figure 1. MSU38225 inhibits transcriptional activity of Nrf2.

A. Chemical structure of MSU38225. B. MCF-7 reporter cells (B-C) stably transfected with a NRF2/ARE luciferase construct were treated with various concentrations of MSU38225 and stimulated with 20 μM tert-butylhydroquinone (tBHQ) for 24 hours. Luciferase activity was detected and normalized to the DMSO control. C. Cell viability was detected using a CellTiter-Fluor assay just prior to the luciferase assay. D. A549 cells (D-E) were treated with 5 μM MSU38225 for 24 hours, and the mRNA expression of NFE2L2 and target genes downstream of Nrf2 were detected using RT-qPCR. Results were normalized to the reference gene GAPDH and the DMSO control. *, p<0.05 vs. DMSO control. E. A549 cells were treated with 5 μM MSU38225 for 24 hours, and the protein expression of Nrf2 and its downstream target HO-1 was detected using western blotting.