Figure 5. Dual luciferase reporter gene assay and ChIP assay. (A) Strategies for the construction of PIK3CA and PIK3CG promoter vectors including wild type and mutant type (the predicted MEF2 binding sites were mutated). (B and C) PIK3CA and PIK3CG promoter vectors (wild and mutant) were cotransfected into 293T cells with the empty expression vector (pc3-gab) or the overexpression vector of MEF2A (pc3-gab-MEF2A-2), respectively. (D) Chromosome immunoprecipitation assay. NC: Negative control, the PCR primers were designed to be located away from the MEF2 binding site. The numbers indicated the position of the predicted MEF2 binding sites in the promoter region. *, P < 0.05, indicates a statistically significant difference.