Glucose-Independent Glutamine-Driven TCA Cycle in Cancer Cells

2014 ◽  
pp. 77-85 ◽  
Author(s):  
Brad Poore ◽  
Nicholas Siegel ◽  
Joshua K. Park ◽  
Benjamin Jung Hwang ◽  
Iman Afif ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Tca Cycle

scholarly journals Remodeling of Cancer-Specific Metabolism under Hypoxia with Lactate Calcium Salt in Human Colorectal Cancer Cells

Cancers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1518
Author(s):  
Keun-Yeong Jeong ◽  
Jae-Jun Sim ◽  
Min Hee Park ◽  
Hwan Mook Kim
Keyword(s):  
Colorectal Cancer ◽  
Intracellular Calcium ◽  
Cancer Cells ◽  
Calcium Salt ◽  
Lactate Production ◽  
Tca Cycle ◽  
Anaerobic Glycolysis ◽  
Human Colorectal Cancer ◽  
Antitumor Effects ◽  
Enzymatic Activation

Hypoxic cancer cells meet their growing energy requirements by upregulating glycolysis, resulting in increased glucose consumption and lactate production. Herein, we used a unique approach to change in anaerobic glycolysis of cancer cells by lactate calcium salt (CaLac). Human colorectal cancer (CRC) cells were used for the study. Intracellular calcium and lactate influx was confirmed following 2.5 mM CaLac treatment. The enzymatic activation of lactate dehydrogenase B (LDHB) and pyruvate dehydrogenase (PDH) through substrate reaction of CaLac was investigated. Changes in the intermediates of the tricarboxylic acid (TCA) cycle were confirmed. The cell viability assay, tube formation, and wound-healing assay were performed as well as the confirmation of the expression of hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF). In vivo antitumor effects were evaluated using heterotopic and metastatic xenograft animal models with 20 mg/kg CaLac administration. Intracellular calcium and lactate levels were increased following CaLac treatment in CRC cells under hypoxia. Then, enzymatic activation of LDHB and PDH were increased. Upon PDH knockdown, α-ketoglutarate levels were similar between CaLac-treated and untreated cells, indicating that TCA cycle restoration was dependent on CaLac-mediated LDHB and PDH reactivation. CaLac-mediated remodeling of cancer-specific anaerobic glycolysis induced destabilization of HIF-1α and a decrease in VEGF expression, leading to the inhibition of the migration of CRC cells. The significant inhibition of CRC growth and liver metastasis by CaLac administration was confirmed. Our study highlights the potential utility of CaLac supplementation in CRC patients who display reduced therapeutic responses to conventional modes owing to the hypoxic tumor microenvironment.

scholarly journals A Critical Role of Glutamine and Asparagine γ-Nitrogen in Nucleotide Biosynthesis in Cancer Cells Hijacked by an Oncogenic Virus

mBio ◽  
2017 ◽  
Vol 8 (4) ◽  
Author(s):  
Ying Zhu ◽  
Tingting Li ◽  
Suzane Ramos da Silva ◽  
Jae-Jin Lee ◽  
Chun Lu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cancer Cells ◽  
Metabolic Pathway ◽  
Tca Cycle ◽  
Glutamine Metabolism ◽  
Transformed Cells ◽  
Oncogenic Virus ◽  
Phosphoribosyl Pyrophosphate ◽  
Rate Limiting

ABSTRACT While glutamine is a nonessential amino acid that can be synthesized from glucose, some cancer cells primarily depend on glutamine for their growth, proliferation, and survival. Numerous types of cancer also depend on asparagine for cell proliferation. The underlying mechanisms of the glutamine and asparagine requirement in cancer cells in different contexts remain unclear. In this study, we show that the oncogenic virus Kaposi’s sarcoma-associated herpesvirus (KSHV) accelerates the glutamine metabolism of glucose-independent proliferation of cancer cells by upregulating the expression of numerous critical enzymes, including glutaminase 2 (GLS2), glutamate dehydrogenase 1 (GLUD1), and glutamic-oxaloacetic transaminase 2 (GOT2), to support cell proliferation. Surprisingly, cell crisis is rescued only completely by supplementation with asparagine but minimally by supplementation with α-ketoglutarate, aspartate, or glutamate upon glutamine deprivation, implying an essential role of γ-nitrogen in glutamine and asparagine for cell proliferation. Specifically, glutamine and asparagine provide the critical γ-nitrogen for purine and pyrimidine biosynthesis, as knockdown of four rate-limiting enzymes in the pathways, including carbamoylphosphate synthetase 2 (CAD), phosphoribosyl pyrophosphate amidotransferase (PPAT), and phosphoribosyl pyrophosphate synthetases 1 and 2 (PRPS1 and PRPS2, respectively), suppresses cell proliferation. These findings indicate that glutamine and asparagine are shunted to the biosynthesis of nucleotides and nonessential amino acids from the tricarboxylic acid (TCA) cycle to support the anabolic proliferation of KSHV-transformed cells. Our results illustrate a novel mechanism by which an oncogenic virus hijacks a metabolic pathway for cell proliferation and imply potential therapeutic applications in specific types of cancer that depend on this pathway. IMPORTANCE We have previously found that Kaposi’s sarcoma-associated herpesvirus (KSHV) can efficiently infect and transform primary mesenchymal stem cells; however, the metabolic pathways supporting the anabolic proliferation of KSHV-transformed cells remain unknown. Glutamine and asparagine are essential for supporting the growth, proliferation, and survival of some cancer cells. In this study, we have found that KSHV accelerates glutamine metabolism by upregulating numerous critical metabolic enzymes. Unlike most cancer cells that primarily utilize glutamine and asparagine to replenish the TCA cycle, KSHV-transformed cells depend on glutamine and asparagine for providing γ-nitrogen for purine and pyrimidine biosynthesis. We identified four rate-limiting enzymes in this pathway that are essential for the proliferation of KSHV-transformed cells. Our results demonstrate a novel mechanism by which an oncogenic virus hijacks a metabolic pathway for cell proliferation and imply potential therapeutic applications in specific types of cancer that depend on this pathway.

scholarly journals CBMT-49. OXALOACETATE ALTERS GLUCOSE METABOLISM IN GLIOBLASTOMA: 13C ISOTOPOMER STUDY

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi43-vi44
Author(s):  
Omkar Ijare ◽  
David Conway ◽  
Alan Cash ◽  
David Baskin ◽  
Kumar Pichumani
Keyword(s):  
Glucose Metabolism ◽  
Cancer Cells ◽  
Neuronal Cell ◽  
Tca Cycle ◽  
Positive Effects ◽  
Isotopomer Analysis ◽  
Carboxylation Pathway ◽  
13C Isotopomer Analysis ◽  
Positive Effect

Abstract Anhydrous enol-oxaloacetate (AEO) has demonstrated the ability to enhance neuronal cell bioenergetics and activate brain mitochondrial biogenesis. Since oxaloacetate has demonstrated positive effects on brain bioenergetics in neurodegenerative diseases we have begun to investigate whether AEO may also have a positive effect on the altered cellular metabolism found in cancer cells, particularly Glioblastoma multiforme. The “Warburg effect” describes an abnormal metabolic state in cancer, distinct from normal tissue, in which energy is generated through enhanced conversion of pyruvate to lactate even in the presence of oxygen during glycolysis. Oxaloacetate (OAA) is a key anaplerotic substrate that is required to maintain TCA cycle flux. The role of oxaloacetate supplementation on the energy metabolism is not known in cancer cells. Goal of this study is to investigate the changes in metabolic fluxes in glucose metabolism with and without the presence of OAA in patient-derived GBM cells. We use GC-MS based 13C isotopomer analysis for this study. GBM cells are grown in 15mM glucose containing DMEM medium supplemented with 2mM oxaloacetate for 10 days. 6 hours prior to harvesting, [U-13C]glucose is introduced to the medium. 13C isotopomer analysis of GC-MS data showed that OAA supplementation for 10 days drastically decreased Warburg glycolysis by reducing 13C labeling (M+3) by 19.7% and 48.8% in pyruvate and lactate pools respectively in comparison with cells not treated with OAA. M+3 13C labeled pyruvate entered TCA cycle via acetyl-CoA, where we also observed reduced levels of M+2 13C labeled citrate (20.5%) and glutamate (23.9%) isotopomers. Pyruvate can also enter TCA cycle via pyruvate carboxylation pathway and this activity was also found to be slightly decreased in the OAA treated cells. All the differences were statistically significant. These results indicate that OAA can be used to alter bioenergetics of GBM cells, specifically glucose oxidation.

scholarly journals Metabolic Constants and Plasticity of Cancer Cells in a Limiting Glucose and Glutamine Microenvironment—A Pyruvate Perspective

2020 ◽  
Vol 10 ◽  
Author(s):  
Angela M. Otto
Keyword(s):  
Cancer Cells ◽  
Metabolic Network ◽  
Metabolic Pathways ◽  
Cancer Cell Line ◽  
Tca Cycle ◽  
Reaction Rates ◽  
Diagnostic Methods ◽  
Metabolic Reprogramming ◽  
Amino Acid Synthesis ◽  
The Tca Cycle

The metabolism of cancer cells is an issue of dealing with fluctuating and limiting levels of nutrients in a precarious microenvironment to ensure their vitality and propagation. Glucose and glutamine are central metabolites for catabolic and anabolic metabolism, which is in the limelight of numerous diagnostic methods and therapeutic targeting. Understanding tumor metabolism in conditions of nutrient depletion is important for such applications and for interpreting the readouts. To exemplify the metabolic network of tumor cells in a model system, the fate 13C6-glucose was tracked in a breast cancer cell line growing in variable low glucose/low glutamine conditions. 13C-glucose-derived metabolites allowed to deduce the engagement of metabolic pathways, namely glycolysis, the TCA-cycle including glutamine and pyruvate anaplerosis, amino acid synthesis (serine, glycine, aspartate, glutamate), gluconeogenesis, and pyruvate replenishment. While the metabolic program did not change, limiting glucose and glutamine supply reduced cellular metabolite levels and enhanced pyruvate recycling as well as pyruvate carboxylation for entry into the TCA-cycle. Otherwise, the same metabolic pathways, including gluconeogenesis, were similarly engaged with physiologically saturating as with limiting glucose and glutamine. Therefore, the metabolic plasticity in precarious nutritional microenvironment does not require metabolic reprogramming, but is based on dynamic changes in metabolite quantity, reaction rates, and directions of the existing metabolic network.

scholarly journals O-GlcNAcylation of PGK1 coordinates glycolysis and TCA cycle to promote tumor growth

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Hao Nie ◽  
Haixing Ju ◽  
Jiayi Fan ◽  
Xiaoliu Shi ◽  
Yaxian Cheng ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Cancer Cells ◽  
Tumor Development ◽  
Lactate Production ◽  
Phosphoglycerate Kinase ◽  
Tca Cycle ◽  
Human Colon ◽  
Colon Cancers ◽  
The Tca Cycle ◽  
Promote Tumor Growth

AbstractMany cancer cells display enhanced glycolysis and suppressed mitochondrial metabolism. This phenomenon, known as the Warburg effect, is critical for tumor development. However, how cancer cells coordinate glucose metabolism through glycolysis and the mitochondrial tricarboxylic acid (TCA) cycle is largely unknown. We demonstrate here that phosphoglycerate kinase 1 (PGK1), the first ATP-producing enzyme in glycolysis, is reversibly and dynamically modified with O-linked N-acetylglucosamine (O-GlcNAc) at threonine 255 (T255). O-GlcNAcylation activates PGK1 activity to enhance lactate production, and simultaneously induces PGK1 translocation into mitochondria. Inside mitochondria, PGK1 acts as a kinase to inhibit pyruvate dehydrogenase (PDH) complex to reduce oxidative phosphorylation. Blocking T255 O-GlcNAcylation of PGK1 decreases colon cancer cell proliferation, suppresses glycolysis, enhances the TCA cycle, and inhibits tumor growth in xenograft models. Furthermore, PGK1 O-GlcNAcylation levels are elevated in human colon cancers. This study highlights O-GlcNAcylation as an important signal for coordinating glycolysis and the TCA cycle to promote tumorigenesis.

scholarly journals 1,25(OH)2D3 disrupts glucose metabolism in prostate cancer cells leading to a truncation of the TCA cycle and inhibition of TXNIP expression

2017 ◽  
Vol 1864 (10) ◽  
pp. 1618-1630 ◽  
Author(s):  
Mohamed A. Abu el Maaty ◽  
Hamed Alborzinia ◽  
Shehryar J. Khan ◽  
Michael Büttner ◽  
Stefan Wölfl
Keyword(s):  
Prostate Cancer ◽  
Glucose Metabolism ◽  
Cancer Cells ◽  
Tca Cycle ◽  
Prostate Cancer Cells ◽  
The Tca Cycle

scholarly journals Mitochondrial metabolism in TCA cycle mutant cancer cells

Cell Cycle ◽  
2013 ◽  
Vol 13 (3) ◽  
pp. 347-348 ◽  
Author(s):  
Lucas B Sullivan ◽  
Navdeep Chandel
Keyword(s):  
Cancer Cells ◽  
Tca Cycle ◽  
Mitochondrial Metabolism

scholarly journals Repression of LKB1 by miR-17∼92 sensitizes MYC-dependent lymphoma to biguanide treatment

2019 ◽  
Author(s):  
Said Izreig ◽  
Alexandra Gariepy ◽  
Ariel O. Donayo ◽  
Gaëlle Bridon ◽  
Daina Avizonis ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Tumor Cells ◽  
Human Cancer ◽  
Tca Cycle ◽  
Mirna Cluster ◽  
Lymphoma Cells ◽  
Ampk Signaling ◽  
Potential Biomarker

AbstractCancer cells display metabolic plasticity to survive metabolic and energetic stresses in the tumor microenvironment, prompting the need for tools to target tumor metabolism. Cellular adaptation to energetic stress is coordinated in part by signaling through the Liver Kinase B1 (LKB1)-AMP-activated protein kinase (AMPK) pathway. Reducing LKB1-AMPK signaling exposes metabolic vulnerabilities in tumor cells with potential for therapeutic targeting. Here we describe that miRNA-mediated silencing of LKB1 (mediated by the oncogenic miRNA cluster miR-17∼92) confers sensitivity of lymphoma cells to mitochondrial inhibition by biguanides. Using both classic (phenformin) and novel (IM156) biguanides, we demonstrate that Myc+ lymphoma cells with elevated miR-17∼92 expression display increased sensitivity to biguanide treatment both in cell viability assays in vitro and tumor growth assays in vivo. This increased biguanide sensitivity is driven by miR-17-dependent silencing of LKB1, which results in reduced AMPK activation in response to bioenergetic stress. Mechanistically, biguanide treatment inhibits TCA cycle metabolism and mitochondrial respiration in miR-17∼92-expressing tumor cells, targeting their metabolic vulnerability. Finally, we demonstrate a direct correlation between miR-17∼92 expression and biguanide sensitivity in human cancer cells. Our results identify miR-17∼92 expression as a potential biomarker for biguanide sensitivity in hematological malignancies and solid tumors.One Sentence SummarymiR-17∼92 expression in Myc+ tumors sensitizes cancer cells to biguanide treatment by disrupting bioenergetic stability in lymphoma cells.

scholarly journals OTME-9. Comprehensive Metabolic Profiling Of high MYC Medulloblastoma Reveals Key Differences Between In Vitro And In Vivo Glucose And Glutamine Usage

2021 ◽  
Vol 3 (Supplement_2) ◽  
pp. ii15-ii15
Author(s):  
Khoa Pham ◽  
Brad Poore ◽  
Allison Hanaford ◽  
Micah J Maxwell ◽  
Heather Sweeney ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Tca Cycle ◽  
Genetic Mutations ◽  
Metabolic Profiles ◽  
Normal Brain ◽  
Genomic Amplification ◽  
Cells In Culture ◽  
Orthotopic Xenograft

Abstract Reprograming of cellular metabolism is a hallmark of cancer. The metabolic alterations in cancer cells is not only defined by series of genetic mutations, but also reflecting the crosstalk between cancer cells and other factors in the microenvironment. Altering metabolism allows cancer cells to overcome unfavorable conditions, to proliferate and invade. Medulloblastoma is the most common malignant brain tumor of children. Genomic amplification of MYC is a hallmark of a subset of poor-prognosis medulloblastoma. However, the metabolism of high MYC amplified medulloblastoma subgroup remains underexplored. We performed comprehensive metabolic studies of human MYC-amplified medulloblastoma by comparing the metabolic profiles of tumor cells in different environments – in vitro, in flank xenografts and in orthotopic xenografts. Principal component analysis showed that the metabolic profiles of brain and flank high-MYC medulloblastoma tumors clustered closely together and separated away from normal brain and the high-MYC medulloblastoma cells in culture. Compared to normal brain, MYC-amplified medulloblastoma orthotopic xenograft tumors showed upregulation of nucleotide, hexosamine biosynthetic pathway (HBP), TCA cycle, and amino acid and glutathione pathways. There was significantly higher glucose up taking and usage in orthotopic xenograft tumor compared to flank xenograft and cells in culture. The data demonstrated that glucose was the main carbon source for the glutamate, glutamine and glutathione synthesis through the TCA cycle. The glutaminase ii pathway was the main pathway utilizing glutamine in MYC-amplified medulloblastoma in vivo. Glutathione was found as the most abundant upregulated metabolite. Glutamine derived glutathione was mainly synthesized through glutamine transaminase K (GTK) enzyme in vivo. In conclusion, we demonstrated that high MYC medulloblastoma adapt to different environments by altering its metabolic pathways despite carrying the same genetic mutations. Glutamine antagonists may have therapeutic applications in human patients.

scholarly journals Reactive Oxygen Species, Metabolic Plasticity, and Drug Resistance in Cancer

2020 ◽  
Vol 21 (10) ◽  
pp. 3412 ◽  
Author(s):  
Vikas Bhardwaj ◽  
Jun He
Keyword(s):  
Reactive Oxygen Species ◽  
Cancer Cells ◽  
Reactive Oxygen ◽  
Tca Cycle ◽  
Metabolic Adaptation ◽  
Oxygen Species ◽  
Metabolic Plasticity ◽  
The Tca Cycle ◽  
Clinical Benefits ◽  
High Level

The metabolic abnormality observed in tumors is characterized by the dependence of cancer cells on glycolysis for their energy requirements. Cancer cells also exhibit a high level of reactive oxygen species (ROS), largely due to the alteration of cellular bioenergetics. A highly coordinated interplay between tumor energetics and ROS generates a powerful phenotype that provides the tumor cells with proliferative, antiapoptotic, and overall aggressive characteristics. In this review article, we summarize the literature on how ROS impacts energy metabolism by regulating key metabolic enzymes and how metabolic pathways e.g., glycolysis, PPP, and the TCA cycle reciprocally affect the generation and maintenance of ROS homeostasis. Lastly, we discuss how metabolic adaptation in cancer influences the tumor’s response to chemotherapeutic drugs. Though attempts of targeting tumor energetics have shown promising preclinical outcomes, the clinical benefits are yet to be fully achieved. A better understanding of the interaction between metabolic abnormalities and involvement of ROS under the chemo-induced stress will help develop new strategies and personalized approaches to improve the therapeutic efficiency in cancer patients.

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