Long-Term Alteration of Reactive Oxygen Species Led to Multidrug Resistance in MCF-7 Cells

Figure 6

The iROS level in MCF-7, MCF-7/ADM, MCF-7/ROS, and MCF-7/GSH cells. MCF-7 and MCF-7/ADM cells were obtained from American Type Culture Collection (ATCC, Manassas, VA, USA) and KeyGen Biotech (Nanjing, China). MCF-7/ROS and MCF-7/GSH cells were MCF-7 cells, respectively, treated with 0.1 μM H₂O₂ and 0.1 mM GSH every other day for successive 20 weeks. Cells were maintained in PBS and incubated with 50 μM DHE for 30 min and then harvested to analyze DHE-derived products by HPLC. Inset, representative chromatogram profile of EOH and E separation in cell extract. Data represents the mean ± SD, . Significant differences relative to MCF-7 cells were indicated as and .