Figure 4. Inhibition of SRF suppressed slug expression upregulation in vitro. (A–C) NRK-52E cells were transfected with pcDNA3.1-SRF or empty pcDNA3.1 vectors. After 24 h, the cells were incubated with different doses of CCG-1423 for another 24 h. The protein and mRNA expression levels of slug were measured by western blot analysis and quantitative RT-PCR. (D) Slug promoter activity was analyzed by measuring luminescence. (E) Chromatin immunoprecipitation was used to examine SRF binding to the slug promoter in NRK-52E cells. Reaction controls included immunoprecipitations performed using a nonspecific IgG monoclonal antibody; PCR was performed using whole cell genomic DNA (Input). N=6 in each group. *P<0.05 versus the pcDNA3.1 group; #P<0.05 versus the pcDNA-SRF group. All experiments were repeated three times.