FIGURE 3.

Reactive oxygen species (ROS)‐induced degradation of signal transducer and activator of transcription 1 (STAT1). The expression levels of STAT1 in HCT116 (A), Caco2 (C), and A549 (D) cells treated with different concentrations of H₂O₂ were detected by Western blot (WB), respectively. (B) Quantitative polymerase chain reaction (qPCR) results showed that the STAT1 mRNA levels did not change under H₂O₂ treatment in HCT116 cells. (E) The proliferation of HCT116 cells was not affected by different concentrations of H₂O₂ treatment for 12 h. (F) The expression of STAT1 in untreated and H₂O₂‐treated HCT116 cells with or without pretreatment with 6 mM N‐acetylcysteine (NAC). Means ± SEM, **p < 0.01, ***p < 0.001, ****p < 0.0001; ns, not significant; one‐way analysis of variance (ANOVA) test.