Imexon treatment results in increased nuclear protein expression of Nrf2. A, Western blot of nuclear extracts prepared from RPMI8226 myeloma cells treated with 0, 100, 300, and 500 μmol/L imexon for 1, 4, and 16 h and probed with antibodies for Nrf1 and Nrf2. Lamin A/C was used as loading control. B, Western blot of cytoplasmic extracts prepared as described above. Actin was used as a loading control. NS, nonspecific band. C, Western blot of nuclear and cytoplasmic extracts prepared from MDA-mb-231 breast cancer cells treated with 0, 100, 300, and 500 μmol/L imexon for 16 h and probed with antibodies for Nrf2 and lamin A/C or actin as loading controls.