Figure 6.

High Level of ROS Activates p38 and Confers 4-OHT Resistance

(A and B) Cells were treated with 5 mM NAC for 2 h, washed with PBS twice, and treated with serially diluted 4-OHT for 72 h. Shown in (A) are comparisons for MCF-7 cells transfected with an empty vector and without NAC treatment, or AK4-overexpressing MCF-7 cells with or without NAC treatment. Displayed in (B) are the comparisons for MCF-7 cells without NAC treatment, or TamR MCF-7 cells with or without NAC treatment. Cell viability was measured using CCK8, and luminescence was recorded with a BioTek reader. The data were normalized to control groups (DMSO) and are represented by the mean ± SD (n = 3). (C and D) Cells were treated with 5 mM NAC for 1 h, and the lysates were used to monitor the levels of AK4, p-p38, and p38 by western blot analyses. Shown in (C) are the results for MCF7 cells without NAC treatment, and TamR MCF-7 cells with or without NAC treatment; displayed in (D) are the results for MCF-7 cells transfected with an empty vector and without NAC treatment, or AK4-overexpressing MCF7 cells with or without NAC treatment.