Western blotting was performed as described previously (Xie et al., 2017 (link)) with slight modifications. Cell pellets were resuspended in lysis buffer (50 mM Tris pH 7.4, 150 mM NaCl, 0.5% Triton X-100, 1mM EDTA pH 8.0, and protease cocktail inhibitor). Soluble extracts were prepared by centrifugation (14,000 × g for 20 min at 4°C). Cell lysates were separated by 6–15% SDS-PAGE and then transferred to nitrocellulose membranes (GE Healthcare). Membranes were blocked for 1 h with 3% dried skim milk in TBST (50 mM Tris pH 8.0, 150 mM NaCl, and 0.5% Tween 20) and incubated with the following primary antibodies, anti-HA (Santa Cruz, sc-805), anti-FLAG (Sigma Aldrich, F1804), anti-MYC (Cell Signaling, #2276), anti-BCL-xL (Cell Signaling, #2764), anti-MCL-1 (Santa Cruz, sc-819), anti-ACTIN (Santa Cruz, sc-47778), anti-GAPDH (Santa Cruz, sc-32233), anti-BCL2 (Santa Cruz, sc-7382), anti-BAX (Santa Cruz, sc-493), and anti-PARP1 (Santa Cruz, sc-7150). After incubation with primary antibodies, the membranes were incubated with the appropriate peroxidase-conjugated secondary antibodies (GeneDEPOT, USA). Protein expression was detected by enhanced chemiluminescence (ECL) reagents and LAS-3000 image analyzer (Fujifilm, Japan).