Figure 3
Effect of mPEPCK downregulation on 5-FU response in SNU-C4 cells. (a) Suppressed mPEPCK expression in SNU-C4 cells transfected with mPEPCK siRNA. The PEPCK expression levels decreased over time in the mPEPCK siRNA-transfected cells, while the nonsilenced (NS) control showed no apparent changes in the PEPCK expression levels. (b) Decreased cell proliferation rate after mPEPCK suppression. With no 5-FU or radiation treatment, artificial suppression of mPEPCK decreased the rate of cell proliferation. (c) Reduced cellular PEP level after mPEPCK suppression. (d) Increased 5-FU and radiation resistance was observed after mPEPCK suppression in SNU-C4 cells. MTT assay showed that the mPEPCK siRNA-transfected SNU-C4 cells exhibited higher survival rates than the control after combination treatment comprising 5-FU and radiation.