Figure 5

Snail binds to the maspin promoter. 22Rv1 cell lines stably overexpressing Snail (Snail-high clone) or vector control (Neo) were utilized to perform ChIP analysis. (A) The maspin promoter region is shown with the putative E-boxes; the ChIP Q-PCR primer recognized the first E-box upstream of the start site. (B) Chromatin was immunoprecipitated with mouse IgG as a negative control, anti-RNA polymerase II antibody as a positive control or anti-Snail antibody. Real-time PCR was subsequently performed with primers that recognize the maspin promoter within the first E-box upstream of the start site. The samples were run on an agarose gel and input included as control for loading. ChIP PCR was also performed with primers to maspin intron as another negative control. (C) The results of the real-time PCR were plotted as fold change of binding to maspin promoter. The experiments were performed in triplicate at least three times independently. Bars, SD *, P < 0.05, Student’s t test compared with 22Rv1 Neo control.