Binding of transactivators to COX-2 promoter is reduced in pFb vs. SF-Fb.
SF-Fb and pFb were treated with or without PMA (100 nM) for 4 h. A). Binding of transactivators to COX-2 promoter was analyzed by ChIP. The precipitated promoter DNA was measured by qPCR. The results were expressed as ratio (fold) of COX-2 promoter precipitated by each transactivator antibody to input DNA. COX-2 promoter precipitated by an non-immune IgG was included as a negative control. “▪ COX-2” denotes core promoter region and “□ control” denotes negative region. The error bars denote mean ± SEM of three independent experiments (n = 3). B). Transactivator proteins in nuclear extracts were analyzed by Western blotting. C) and D). Analysis of concurrent binding of transactivators (C) and p300 (D) to a COX-2 probe (denoted “COX-2”) or control probe (denoted “C”) by streptavidin agarose pulldown assay. D). p300 proteins in nuclear extract were analyzed by Western blotting. The upper panel shows a representative blot and the lower panel, densitometry of the blot. The error bars denote mean ± SEM (n = 3). “SF” denotes SF-Fb and “P” denotes pFb.