Selective BH3 mimetics synergize with BET inhibition to induce mitochondrial apoptosis in rhabdomyosarcoma cells

•Co-inhibition of BET proteins and anti-apoptotic BCL-2 proteins induces apoptosis in RMS.•JQ1 and BH3-mimetics synergistically induce cell death in RMS.•Cell death is caspase-dependent and displays hallmarks of intrinsic apoptosis.•JQ1/A-1331852-mediated apoptosis is dependent on BIM and NOXA.•JQ1/S638450-mediated apoptosis is dependent on BIM but not NOXA.