Bovine serum albumin reagent

Cells were placed on ice immediately following treatment and washed with ice-cold Hank’s Balanced Salt Solution. Nuclear proteins were prepared using the CellLytic NuCLEAR extraction kit (Sigma-Aldrich). All the wash buffers and final resuspension buffer included a 1× protease inhibitor cocktail (Pierce, Rockford, IL, USA), NaF (5 mM), and Na3VO4 (200 mM). The protein concentration of the lysate was measured using the BCA protein assay kit (Thermo Fisher). Nuclear or total cell proteins were resolved on 8 to 12% SDS-PAGE and transferred by electroblotting to nitrocellulose membranes (Bio-Rad, Hercules, CA, USA). The membranes were blocked in 5% bovine serum albumin reagent (Beyotime, Jiangsu, China) and incubated overnight at 4 °C with primary antibody dilution buffer (the dilution followed the specification; Abcam) and then incubated with horseradish peroxidase-conjugated anti-rabbit IgG (1:5000) for 2 h. Afterward, the membranes were developed using the enhanced chemiluminescence substrate LumiGLO (Millipore, Bedford, MA, USA) and exposed to X-ray film. The bands were analyzed with Gel-Pro Analyzer 4.0 (Bio-Rad, Hercules, CA, USA).