Western Blotting of Xenograft Proteins

Western blotting was performed as previously described^{22 (link), 23 (link), 46 (link)}. The lysates from the xenografts or cell lines with different treatments were homogenized in RIPA lysis buffer using a homogenizer. The supernatants were collected by centrifugation (12,000 rpm at 4 °C for 25 min; Beckman GS-6R). Protein was resolved by electrophoresis and transferred onto polyvinylidene fluoride (PVDF) membranes (Millipore, Bedford, MA, USA). The membranes were probed with monoclonal HIF-1α (NB100–105, Novus biological, Littleton, CO, USA), Bax (2772 S, Cell signaling, Boston, MA, USA), Bcl-2 (3498S, Cell signaling), caspase-3 (9661S, Cell signaling), PARP (5625, Cell signaling), and PCNA (18197, Abcam, Cambridge, MA, USA), as well as p21 (Sc817, Santa Cruz, CA, USA), CDK4 (Sc70831, Santa Cruz), SP1 (ab27595, Abcam), HK2 (2772S, Cell signaling), PKM2 (4053S, Cell signaling), LDH-A (3582S, Cell signaling), and PDK1 (3820 S, Cell signaling). Following incubation with the primary antibody overnight at 4 °C, membranes were washed with Tris-buffered saline (pH 7.2) containing 0.05% Tween-20 and subsequently incubated with horse radish peroxidase (HRP)-conjugated anti-mouse (Sc-2005, Santa Cruz) or anti-rabbit (Sc-2357, Santa Cruz) secondary antibody for 1 h at room temperature. Bands of interest were analyzed using the ChemiDocTM Touch Imaging System (BIO-RAD, Hercules, CA, USA).