(A) Schematic representation of wildtype BRD9 and BRD7, and the chimeric BRD9 bromodomain swap containing the BRD7 bromodomain (top panel). Western blot analysis of the indicated proteins in HSSYII cells expressing vector (control), BRD9-WT or BRD9 containing the bromodomain of BRD7 (BRD9-BD7) treated with dBRD9-A at 100 nM for 6 hr (bottom panel). (B) Growth assays of HSSYII cells (as in panel a) cultured in the presence of dBRD9-A at 100 nM for a total of 9 days. (C) Mouse weight measurements in vehicle control and dBRD9-A treated mice. Mean ±s.d., n = 5. (D) Complete blood counts (CBCs) performed on vehicle control and dBRD9-A treated mice. Measurements were taken on day-23 of the 24 day treatment experiment. Mean ±s.d., n = 5. (E) Box plot representation of the relative abundance of BRD9 and SS18-SSX1 ChIP-seq signal at promoter, typical enhancer and super enhancer elements. P values are from Welch’s two-tailed t-tests. ***p≤0.001. (F) Box plot representations of changes in SS18-SSX1 occupancy at active promoters, typical enhancers and super enhancers comparing DMSO and dBRD9-A treated HSSYII cells. P values are from Welch’s two-tailed t-tests. *p≤0.05, ***p≤0.001. (G) Venn diagram representing the proportion of overlap between all up/down-regulated genes (±1.5 fold) in dBRD9-A treated cells at 6 hr post-treatment with all direct SS18-SSX target genes.