Knockdown of Beclin-1 diminishes the effect of ABT-737. A. shRNA knockdown of BECN1 (KD) or scrambled control (SCR) was performed in H209 and H345 cells. After puromycin selection, cell lysates were harvested and Western blot analysis was performed using antibodies specific for Beclin-1 or GAPDH. B. Cells were treated with ABT-737 (0.1 μM), CQ (12.5 μM) or the combination for 72 hrs and then assayed using the Caspase-Glo 3/7 kit. The y-axis shows fold differences in caspase activation between treatments compared to DMSO treated samples. Error bars: SD; n = 4.