Figure 8. Fraxetin drove ROS-mediated apoptosis by regulating the STAT3-Ref1 axis. (A, B) Flow cytometric analysis showing the levels of ROS in fraxetin-treated PANC-1 and Patu8988 cells. (C) Immunocytochemical staining showing the levels of ROS in fraxetin-treated PANC-1 and Patu8988 cells. Bar = 25 μm. (D) Ref1 expression in fraxetin-treated PANC-1 and Patu8988 cells as seen on a Western blot. (E) Immunocytochemical staining showing Ref1 expression in fraxetin-treated PANC-1 and Patu8988 cells. Bar = 50 μm. (F) The correlation between STAT3 and APE1 (encoding Ref1 protein) in the GEPIA 2 database was evaluated. (G) Ref1 expression in fraxetin-treated PANC-1 and Patu8988 cells with or without colivelin treatment, as determined by Western blot analysis. Data were presented as the mean ± standard deviation, and were analyzed by One-way ANOVA with Bonferroni’s post-hoc test and two-sided Student’s t-test. *P < 0.05; **P < 0.01, ***P < 0.001.