Fig. 5

ROS accumulation modulates the STAT3 activation, migration and invasion induced by gemcitabine and VPA. a After various doses of VPA treatment for 36 h, the relative intracellular ROS level was examined using a DCF-DA probe with FCM. b After pretreatment with 10 mM of NAC for 2 h and then treatment with VPA (0.5 mM or 5 mM) for 12 h in two pancreatic cancer cell lines, cotreatment with gemcitabine was followed for 24 h. Then, the changes in intracellular ROS levels were detected by FCM. c After pretreatment with 10 mM of NAC for 2 h and then treatment with VPA (0.5 mM or 5 mM) for 12 h separately and combined with 5 μm gemcitabine for another 24 h, the changes in the expression levels of Bmi1, p-STAT3 and STAT3 were detected by western blot analysis. d, e The migration and invasion abilities were detected by Transwell migration/invasion assays after the above treatment. *P < 0.05; **P < 0.01; ***P < 0.001 compared with the control. The graphs show the results of three independent experiments