Fig. 4. Induction of ROS on G9a knockdown enhanced 5-FU induced cell apoptosis in NCI-N87 cells. (A) Percentage of DCF fluorescence in cells pretreated with NAC followed by treatment with 5-FU and siG9a. (B) Western blotting analysis for protein expression of p-JNK was performed on cells pretreated with NAC followed by treatment with 5-FU and siG9a. (C) Cell apoptosis was assessed after cells were pretreated with NAC followed by treatment with 5-FU and siG9a. (D) Western blotting analyses for protein expressions of cleaved PARP1 and caspase-8 were performed in cells pretreated with NAC followed by treatment with 5-FU and siG9a. *P < 0.05, ***P < 0.001.