A-196

U2OS cells are seeded on 6-well plates with 3 μM A-196 or DMSO as a control, and incubated for 48 h. The cells are washed once in 1 X PBS and then lysis buffer (20 mM Tris-HCl pH 7.5, 0.5% Triton X-100, 150 mM NaCl, 1 mM EDTA, 10 mM MgCl2, PMSF, protease inhibitors, benzonase) is added to half the cells to create whole cell extract (WCE). The remaining cells are subjected to sequential cellular fractionation. First the cell pellet is resuspended in hypotonic buffer A (10 mM HEPES pH 7.5, 10 mM KCl, 1.5 mM MgCl2, 0.3 M sucrose, 1 mM DTT and protease inhibitors) and then 0.1% triton X-100 is added. The cells are incubated for 15 min on ice and pelleted by centrifugation at 1,500g. The supernatant is clarified by centrifugation at max speed and saved as the cytoplasmic fraction. The pellet is resuspended in buffer B (3 mM EDTA, 3 mM EGTA, 1 mM DTT and protease inhibitors) and incubated on ice for 40 min and then centrifuged at 1,500g for 5 min. The supernatant is clarified and saved as the nucleoplasmic fraction. The pellet is resuspended in lysis buffer and incubated for 5 min at room temperature before being resuspended in 4× loading dye. The final lysate contains the solubilized chromatin fraction.