Fig. 8: SRF-mediated regulation of MCM7 transcription in ATO-treated HCC.

a The transcription factor binding sites of MCM7 promoter predicted by The Champion ChiP Transcription Factor Search Portal (http://www.sabiosciences.com/chipqpcrsearch.php?app=TFBS) based on SABiosciences’ proprietary database known as DECODE. b WB analysis of MCM7 expression in HCC cell lines 7 days after treatment with 10 μM of PPAR-γ antagonist GW 9662 (M6191, Sigma-Aldrich, St. Louis, MO) and 10 μM of PPAR-γ agonist Rosiglitazone (R2408, Sigma-Aldrich). c A ChIP assay for the detection of SRF and MCM7 promoter binding specificity. M, DNA marker. d WB analysis of SRF expression at indicated time after ATO treatment in HCC cells. e WB analysis of SRF and MCM7 expression in SRF-knockdown HCC cells. f A brightfield image and quantification analysis of the tumorspheres from psicoR-shMCM7-GFP cells and scramble cells. Bars, 1000 μm. g IP with an anti-SRF antibody and analysis by immunoblotting with a MCM7 antibody and SRF antibody in HCC cells treated with ATO or PBS (con). h The dual luciferase assay for reporter gene expression in HeLa cells that were transfected with pGL4-MCM7-promoter luciferase constructs or a combination with pcDNA3.1-MCM7-expressing vectors plus pBPLV-SRF-expressing vectors, with a pGL4-basic vector as the control. Mean ± SD relative luciferase activity was calculated relative to Renilla activity. **P < 0.01, determined by Student’s t-test. i Summarized hypothesis on the ATO-SRF/MCM7 transcription axis in HCC. ATO interacts with MCM7 and inhibits the transcription activity of SRF/MCM7 complex, this in turn leads to the downregulation of MCM7, a key factor in HCC progression