Panels A and B; FRO and SW1736 were exposed to JQ1 or I-BET762 different doses (rising from 50 nM to 10 μM). Cell viability was determined by MTT assay after 0, 24, 48 and 72 h and expressed as a percentage of baseline samples (T0). All samples were run in quadruplicate. Panel C; apoptosis levels were evaluated 48 h after treatment either with 5 μM BET inhibitors or vehicle (NT). Caspase 3/7 levels were normalized to the vehicle-treated group. Temozolomide (500 μM), a chemotherapy drug, was used as a positive control for apoptosis. Each sample was run in triplicate. * p < 0.05, *** p < 0.001, **** p < 0.0001 by ANOVA test. Panel D; FRO and SW1736 cell cycle distribution was determined after 5 μM JQ1 or vehicle administration. Cells were collected after 24, 48 and 72 hours treatments. Data are representative of 3 independent experiments.