Project description:Glucose utilization increases in tumors, a metabolic process that is observed clinically by 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET). However, is increased glucose uptake important for tumor cells, and which transporters are implicated in vivo? In a genetically-engineered mouse model of lung adenocarcinoma, we show that the deletion of only one highly expressed glucose transporter, Glut1 or Glut3, in cancer cells does not impair tumor growth, whereas their combined loss diminishes tumor development. 18F-FDG-PET analyses of tumors demonstrate that Glut1 and Glut3 loss decreases glucose uptake, which is mainly dependent on Glut1. Using 13C-glucose tracing with correlated nanoscale secondary ion mass spectrometry (NanoSIMS) and electron microscopy, we also report the presence of lamellar body-like organelles in tumor cells accumulating glucose-derived biomass, depending partially on Glut1. Our results demonstrate the requirement for two glucose transporters in lung adenocarcinoma, the dual blockade of which could reach therapeutic responses not achieved by individual targeting.
Project description:In a study of GLUT1 and GLUT3, we used RNA-sequencing to assess the affects of GLUT1 and GLUT3 knockdown in the D456 glioblastoma cell line.
Project description:The microenvironment of solid tumors is dynamic and frequently contain pockets of low oxygen levels (hypoxia) surrounded by regions of normal oxygen levels. Indeed, a compromised vascular is a is hallmark of the tumor microenvironment, creating gradients of hypoxia. Notably, hypoxia associates with increased metastasis and poor survival in patients. Therefore, to aid therapeutic decisions and better understand hypoxia's role in cancer progression, it is critical to identify endogenous biomarkers of hypoxia to spatially phenotype oncogenic lesions in human tissue, whether precancerous, benign, or malignant. Here, we characterize the glucose transporter GLUT3/SLC2A3 as a biomarker of hypoxia prostate epithelial cells and prostate tumors. Transcriptomic analyses of hypoxic immortalized prostate epithelial cells revealed a highly significant increase in GLUT3 expression. GLUT3 upregulation was also detected by immunostaining in hypoxic prostate epithelial cells and prostate cancer cell lines. Additionally, GLUT3 dramatically co-localized with the hypoxia-marker pimonidazole in xenograft tumors formed from prostate cancer cells and showed distinct concentration gradients within patient-derived xenograft tumors from primary and metastatic prostate cancer. Compared to established hypoxia-response genes, GLUT1 and CA9, GLUT3 shows a higher degree of hypoxia labeling within tumor tissue and may serve as a alternative endogenous biomarker of hypoxia.
Project description:The tumor microenvironment presents many obstacles to effective CAR T cell therapy, including glucose competition from tumor and myeloid cells. Using mouse models of acute lymphoblastic leukemia (ALL), renal cell carcinoma (RCC), and glioblastoma (GBM), we show that enforced expression of the glucose transporter GLUT1 enhances anti-tumor efficacy and promotes favorable CAR T cell phenotypes for two clinically relevant CAR designs, 19-28z and IL13Ra2-BBz. In the NALM6 ALL model, 19-28z-GLUT1 promotes Tscm formation and prolongs survival. RNA sequencing of these CAR T cells reveals that overexpression of GLUT1, but not GLUT3, enriches for genes involved in glycolysis, mitochondrial respiration, and memory precursor phenotypes. Extending these data, 19-28z-GLUT1 CAR T cells improve tumor control and response to rechallenge in an RCC patient derived xenograft model. Furthermore, IL13Ra2-BBz CAR T cells overexpressing GLUT1 prolong survival of mice bearing orthotopic GBMs and exhibit decreased exhaustion markers. This novel engineering approach can offer a competitive advantage to CAR T cells in harsh tumor environments where glucose is limiting.
Project description:Macrophages (MΦs) are heterogeneous and metabolically flexible with metabolism strongly affecting immune activation. A classic response to pro-inflammatory activation is increased flux through glycolysis with a downregulation of oxidative metabolism, while alternative activation is primarily oxidative which begs the question of whether targeting glucose metabolism is a viable approach to control MΦ activation. We created a murine model of myeloid-specific glucose transporter GLUT1 (Slc2a1) deletion. Bone marrow derived MΦs (BMDM) from Slc2a1M-/- mice failed to uptake glucose and demonstrated reduced glycolysis and Pentose Phosphate Pathway activity. Activated BMDMs displayed elevated metabolism of oleate and glutamine, yet maximal respiratory capacity was blunted in MΦ lacking GLUT1 demonstrating an incomplete metabolic reprogramming. Slc2a1M-/- BMDMs displayed a mixed inflammatory phenotype with reductions of the classically-activated pro- and anti-inflammatory markers, yet less oxidative stress. Slc2a1M-/- BMDMs had reduced pro-inflammatory metabolites, whereas metabolites indicative of alternative activation - such as ornithine and polyamines - were greatly elevated in the absence of GLUT1. Adipose tissue MΦs of lean Slc2a1M-/- mice had increased alternative M2-like activation marker mannose receptor CD206, yet lack of GLUT1 was not a critical mediator in the development of obesity-associated metabolic dysregulation. However, Ldlr-/- mice lacking myeloid GLUT1 developed unstable atherosclerotic lesions. Defective phagocytic capacity in Slc2a1M-/- BMDMs may have contributed to unstable atheroma formation. Together our findings suggest that while lack of GLUT1 blunted glycolysis and PPP, MΦ were metabolically flexible enough that inflammatory cytokine release was not dramatically regulated yet phagocytic defects hindered MΦ function in chronic diseases. Control mice are noted as WT or Slc2a1 fl/fl and myeloid GLUT1 deficient are KO or Slc2a1M-/- (LysMCre X Slc2a1fl/fl) for myeloid deficiency.
Project description:Anucleate platelets circulate in the blood to facilitate thrombosis and diverse immune functions. Platelet activation leading to clot formation correlates with increased glycogenolysis, glucose uptake, glucose oxidation, and lactic acid production. Simultaneous deletion of glucose transporter (GLUT) 1 and GLUT3 (double knockout [DKO]) specifically in platelets completely abolished glucose uptake. In DKO platelets, mitochondrial oxidative metabolism of non-glycolytic substrates, such as glutamate, increased. Thrombosis and platelet activation were decreased through impairment at multiple activation nodes, including Ca2+ signaling, degranulation, and integrin activation. DKO mice developed thrombocytopenia, secondary to impaired pro-platelet formation from megakaryocytes, and increased platelet clearance resulting from cytosolic calcium overload and calpain activation. Systemic treatment with oligomycin, inhibiting mitochondrial metabolism, induced rapid clearance of platelets, with circulating counts dropping to zero in DKO mice, but not wild-type mice, demonstrating an essential role for energy metabolism in platelet viability. Thus, substrate metabolism is essential for platelet production, activation, and survival.
Project description:We performed a pilot proteogenomic study to compare lung adenocarcinoma to lung squamous cell carcinoma using quantitative proteomics (6-plex TMT) combined with a customized Affymetrix GeneChip. Using MaxQuant software, we identified 51,001 unique peptides that mapped to 7,241 unique proteins and from these identified 6,373 genes with matching protein expression for further analysis. We found a minor correlation between gene expression and protein expression; both datasets were able to independently recapitulate known differences between the adenocarcinoma and squamous cell carcinoma subtypes. We found 565 proteins and 629 genes to be differentially expressed between adenocarcinoma and squamous cell carcinoma, with 113 of these consistently differentially expressed at both the gene and protein levels. We then compared our results to published adenocarcinoma versus squamous cell carcinoma proteomic data that we also processed with MaxQuant. We selected two proteins consistently overexpressed in squamous cell carcinoma in all studies, MCT1 (SLC16A1) and GLUT1 (SLC2A1), for further investigation. We found differential expression of these same proteins at the gene level in our study as well as in other public gene expression datasets. These findings combined with survival analysis of public datasets suggest that MCT1 and GLUT1 may be potential prognostic markers in adenocarcinoma and druggable targets in squamous cell carcinoma.
Project description:Glucose uptake increases during B cell activation and plasma cell differentiation. However, conflicting findings regarding the role of glucose at different stages of B cell activation prevents establishing a clear metabolic profile. To determine whether glucose is required for establishing humoral immunity, we deleted the glucose transporter type 1 (GLUT1)-encoding gene (Slc2a1fl/fl) in mature B cells by CD23-mediated Cre expression (GLUT1-cKO). While B cell development was normal, germinal center B cell and antibody-secreting cell numbers (ASCs) were severely reduced in GLUT1-cKO mice. In addition, these mice could hardly mount antigen-specific antibody titers after vaccination. Activation of GLUT1-deficient B cells in vitro was impaired and the remaining plasmablasts abolished glycolysis, relying on mitochondrial activity and fatty acid metabolism. Metabolomics combined with genome-wide transcriptome analysis revealed a dramatically altered anaplerotic balance in GLUT1-deficient ASCs. Although the cells attempt to compensate for glucose deprivation by increasing their mitochondrial mass and the expression of genes responsible for glycolysis, the tricarboxylic acid cycle and the hexosamine synthesis pathways, they lack both the necessary metabolites for energy production and functional mitochondrial respiration. Consequently, protein synthesis was limited in GLUT1-deficient ASCs. Thus, we identified GLUT1 as a critical metabolic player defining the germinal center response and humoral immunity.
Project description:Glucose transporters are the first and rate-limiting step for cellular glucose usage, which is often exacerbated in tumour cells enabling their growth and proliferation. Although inhibiting glucose metabolism in lung tumours could become an efficient treatment strategy, whether and which glucose transporter(s) should be targeted remains unclear because of their possible functional redundancy, and because other nutrients or transporter-independent metabolic processes including autophagy and macropinocytosis can fuel tumour cell growth in certain contexts. Here we show that glucose transporter Glut1 gene deletion in tumour cells does not impact tumour initiation and only slightly delays progression in a genetically-engineered mouse model of lung adenocarcinoma. Using 13C-glucose tracing with correlated nanoscale secondary ion mass spectrometry (NanoSIMS) and electron microscopy, we report the presence of multiple lamellar body-like organelles produced by tumour cells. Glucose-derived biomass accumulates in these organelles, and this accumulation is decreased in Glut1-deficient tumour cells. Ex vivo, tumour cell glycolysis is impaired in absence of Glut1 except in case of strong expression of another glucose transporter, Glut3. We show that Glut3 is dispensable for Glut1 wild-type tumour development. In contrast, their combined deletion diminishes tumour growth and prevents the appearance of big lesions. Our results demonstrate the requirement for two glucose transporters in lung adenocarcinoma; dual blockade could reach therapeutic responses not achieved by individual targeting.