LMP1-mediated glycolysis induces myeloid-derived suppressor cell expansion in nasopharyngeal carcinoma
Fig 4
GLUT1-dependent glycolysis was required for NPC-LMP1-mediated MDSC differentiation.
(A) WB showed the level of GLUT1 in CNE2-LMP1-siNC, CNE2-LMP1-siGLUT1, TW03-LMP1-siNC and TW03-LMP1-siGLUT1 cells, and GAPD was included as the control. (B and C) Representative ECAR assays for CNE2-LMP1-siNC, CNE2-LMP1-siGLUT1, TW03-LMP1-siControl and TW03-LMP1-siGLUT1 cells. The time course and calculations for (B) glycolytic capacity and (C) statistical analysis of glycolytic capacity and glycolytic reserve are shown. (D) Expression of the NLRP3, ASC, caspase-1, IL-1β, COX-2, Arg-1 and iNOS mRNAs was determined via qRT-PCR in CNE2-LMP1-siControl, CNE2-LMP1-siGLUT1, TW03-LMP1-siControl and TW03-LMP1-siGLUT1 cells. (E) Representative immunoblotting of NPC-vector, NPC-LMP1, NPC-LMP1-siNC and NPC-LMP1-siGLUT1 cells stained with the indicated antibodies (n = 5). (F) Secretion of the cytokines IL-1β, IL-6 and GM-CSF from NPC-LMP1 cells following treatment with siGLUT1, siControl (siNC) or 2-DG was determined via ELISA. (G) Statistical analysis of the percentage of CD33+CD11b+HLA-DR-MDSCs mediated by CNE2-LMP1 or TW03-LMP1 cells following treatment with siGULT1, siNC or 2-DG. Data are presented as the means ± SEM of representative experiments performed in triplicate. *P < 0.05, **P < 0.01 compared with the control treatment.