BB and AMO-miR-21 inhibit cell viability and induce apoptosis and G2 phase cell cycle arrest. RPMI-8266 cells were treated with various concentrations of BB and AMO-miR-21 then plated in 96-well plates in medium containing 10% FCS and cultured for another 48 h. Cell viability was assessed by triplicate MTT assays. (A) BB and AMO-miR-21. *p < 0.01 vs. blank and Scramble controls. Both BB and AMO-miR-21 inhibited cell viability in a dose-dependent manner. RPMI-8266 cells were treated with 75 μM BB or 0.5 μM AMO-miR-21. Cells were then stained with FITC-conjugated annexin V and PI for 15 min., and then analyzed by flow cytometry. (B) Both BB and AMO-miR-21 promoted apoptosis and IL6 could reduce BB-induced apoptosis. *p < 0.01 vs. control. (C) Both BB and AMO-miR-21 significantly induced G2-phase cell cycle arrest. *p < 0.01 vs. blank or SCR controls.