(A) Relative mRNA expression levels as determined by qPCR for the unedited DUSP1 gene for unedited parental U2OS-GR cells (wt), for unedited clonal control cell lines, and for clonal cell lines with an integrated GBS as indicated at the IL1R2 gene. Averages ± SEM for cell lines treated for 4, 6, 8, or 10 h with 1 μM dex or vehicle control (−) is shown. Dots indicate the value of each individual clonal cell line. (B) H3K27ac occupancy was analyzed by ChIP followed by qPCR for clonal lines and parental U2OS-GR cells (wt) as indicated treated with vehicle control (−) or 1 μM dex for 90 min. Average percentage of input precipitated ± SEM from three independent experiments is shown for the locus where the GBS was inserted (IL1R2 promoter), the IL1R2 wt peak, a positive control region (GILZ), and a negative control region (TAT). Statistical tests were performed using an unpaired two-sided Mann–Whitney U test comparing the H2K27ac levels at the IL1R2 promoter between dex-treated clonal control and the dex-treated IL1R2 + CGT clonal line.