Epigenetic suppression of the copGFP reporter gene. a. Schematic diagram of the copGFP reporter gene system. b. Inhibition of the transiently-transfected copGFP gene. 293 T cells were transiently co-transfected with copGFP reporter and suppressor vectors. Forty-eight hours post-transfection, copGFP expression was analyzed by luminometer. Each error bar represents the standard error of mean (SEM) of three independent experiments. *Indicates P <0.05 versus pcDNA3.1 control vector. c. Inhibition of the copGFP gene that has been stably integrated in the genome of the target cell. Expression of the copGFP reporter gene was quantitated by real-time quantitative PCR. Each sample was analyzed in quadruplicate. a: P <0.05 as compared with 293 T cells transiently transfected with pcDNA3.1 empty vector; b: P <0.05 as compared with the Sss1 group.