Chromatin remodelers CHD9 and BRM are required for dex-regulated expression of block genes in U2OS-GR⍺ cells

The glucocorticoid-activated glucocorticoid receptor (GR) regulates cellular stress pathways by binding to genomic regulatory elements of target genes and recruiting coregulator proteins to remodel chromatin and regulate transcription complex assembly. The coregulator Hydrogen peroxide-inducible clone 5 (Hic-5) is required for glucocorticoid regulation of some genes, but not others, and blocks regulation of a third gene set. Hic-5 inhibits GR binding to blocked genes but not other glucocorticoid-regulated genes. Site-specific blocking of GR binding is due to gene-specific requirements for ATP-dependent chromatin remodeling enzymes. We investigate whether ATPases CHD9 and BRM were required for glucocorticoid-regulated expression of Hic-5 blocked genes. Since Hic-5 inhibits the actions of CHD9 and BRM, we performed double depletion of Hic-5 and CHD9 or Hic-5 and BRM in U2OS-GR⍺ cell using siRNA and examined gene expression changes at 8 hour dexamethasone (dex) or ethanol (etoh, vehicle control) treatment. Single depletion of CHD9, BRM, Hic-5 and control siRNA (siNS) followed by hormone treatment were performed as contrast and control.