2.3. MTT assay

Cells (3000/well) were seeded into a 96‐well plate. After overnight incubation, culture medium was replaced with fresh medium supplemented with designated reagents (vehicle control, JQ1, 3‐MA and etc). After 48 hours, 200 μL 3‐(4, 5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide (MTT) was added to each well to make a final concentration 0.5 mg/mL 2‐4 hours before harvesting. The medium aspirated carefully and then 150 μL DMSO was added to each well to dissolve the violet sediment. Afterward, the plate was gently vortexed for 5 minutes or until all the precipitation was dissolved. A Bio‐tek mirco‐plate reader (Winooski, VT) was utilized to read the optical density (OD) value with the wavelength set to 490 nm.