Glut1

Cells were lysed using RIPA lysis buffer (Biosharp, Beijing, China) with a protease inhibitor cocktail (Cell Signaling Technology, Boston, MA, USA). Total soluble protein was electrophoresed from 8% to 12% on sodium dodecyl sulfate (SDS)-polyacrylamide gels and transferred onto a polyvinylidene fluoride (PVDF) membrane (Millipore, Burlington, MA, USA). After blocking with 5% albumin from bovine serum (BSA) or skimmed milk for 1 h at room temperature, the blots were probed with primary antibodies to GLUT1 (dilution 1:1000, ABclonal, Wuhan, China), B-cell lymphoma-2 (Bcl-2, dilution 1:5000, Proteintech, Rosemont, IL, USA), BCL2-Associated X (Bax, dilution 1:1000, Proteintech, Rosemont, IL, USA), p-Akt (Ser473), total Akt (dilution 1:1000, ABclonal, Wuhan, China), p-mTOR (Ser2448) or total mTOR (dilution 1:1000, Santacruz Biotechnology, Dallas, TX, USA) and kept overnight at 4 °C, followed by incubation with horseradish peroxidase (HRP)-labeled secondary antibodies (Biofly, Chengdu, China) for 1 h at room temperature. After washing 3 times with 1% TBST, the bands were visualized using an efficient chemiluminescence (ECL) kit (Millipore, Burlington, MA, USA). β-actin (Sigma, Saint Louis, MO, USA) was used as the loading control.

PKM2-IN-1 and NCT-503 were purchased from MedChemExpress (Princeton, NJ, United States). RPMI 1640 and FBS were purchased from Biological Industries (Beit Haemek, Israel). Propidium iodide (PI) was obtained from Sigma-Aldrich (St. Louis, MO, United States). The enhanced chemiluminescence (ECL) reagent was purchased from Thermo Fisher Scientific (Waltham, MA, United States). Antibodies against cyclin B1, cdc2, caspase 3, poly (ADP-ribose) polymerase (PARP), Bax, B-cell lymphoma 2 protein (Bcl-2), pyruvate kinase (PK) M2, phospho-AMP-activated protein kinase (AMPK)α (Thr172), phospho-mTOR (Ser2448), phospho-p70 ribosomal protein S6 Kinase (p70S6K) (Thr389), phospho-histone H2AX (Ser139) (γ-H2AX), p-ATM (Ser 1981), β-actin, and HRP-conjugated goat anti-rabbit and horse anti-mouse secondary antibodies were purchased from Cell Signaling Technology Inc. (Danvers, MA, United States). The anti-p-Chk2 (Thr68) antibody was purchased from Abcam (Cambridge, UK). An antibody specific for PHGDH was purchased from Absin Bioscience Inc. (Shanghai, China). Antibodies against p-p53 (ser15), p53, p21 and Ki67 were purchased from Proteintech Group, Inc (Rosemont, IL, United States). Antibodies against glucose transporter type 1 (GLUT1) was purchased from Abclonal (Woburn, MA, United States).

Control (untreated) and cells treated with perifosine, chetomin, or DMOG were lysed using a Triton X-100-based lysis buffer (1% Triton X-100, 10% glycerol, 150 mM NaCl, 20 mM tris (pH 7.5), 2 mM EDTA) in the presence of protease inhibitors (Thermo Fisher Scientific). Approximately 40 μg of whole cell extract was resuspended in the SDS sample buffer, boiled for 4 min, and analyzed by SDS-PAGE (12% or 15% gels) and then transferred onto PVDF membranes (Genesee) using a semi-dry cell transfer blot (Bio-Rad). Nonfat dry milk (4%) or 5% BSA (for Akt2 and phospho-specific antibodies) in TBST buffer (25 mM tris–HCl, pH 8.0, 125 mM NaCl, 0.1% Tween 20) was used to block the nonspecific binding of the membrane. The membranes were incubated with the indicated primary antibodies: HIF-1α (Bioss Antibodies, 1:2,000), AKT (pan), Akt1, Akt2, Akt3, phospho-Akt-T308, phospho-GSK-3β-S9, ULK1 (Cell Signaling Technology 1:2,000), GLUT1 (ABclonal 1:2,000), MFN2, and β-actin (Santa Cruz Biotechnology, 1:3,000). MUL1 and UBXN7 rabbit polyclonal antibodies were homegrown and used at a 1:5,000 dilution. Secondary peroxidase-conjugated goat anti-rabbit or goat anti-mouse antibodies (Jackson ImmunoResearch) were used at a 1:10,000 dilution. The membrane was visualized by enhanced chemiluminescence (ECL) (Thermo Fisher Scientific).