bims-glucam Biomed News
on Glutamine cancer metabolism
Issue of 2021‒06‒27
eleven papers selected by
Sreeparna Banerjee
Middle East Technical University

  1. Tissue Cell. 2021 Jun 04. pii: S0040-8166(21)00085-9. [Epub ahead of print]71 101569
      γδ T cell is one of the most important pathogenic immune cells in autoimmunity, especially in mucosal and epithelial diseases. Metabolism is essential for the maintenance of immune homeostasis. However, unlike αβ T cells, the metabolic regulation of γδ T cell activation still remain unclear. Here, we identified glutamine metabolism as a critical regulator for the generation of IL-17-producing γδ T cells. Metabolic screening uncovered that amino acids related to glutamine metabolism increased most obviously during γδ T cell activation. Pharmaceutical blocking of glutamine impaired IL-17 production in γδ T cells both in vitro and in vivo. Mechanism studies further revealed that genes downregulated upon glutamine deprivation enriched in IL-17 and IL-23/STAT3 signaling pathways. Consistent with this, the activation of STAT3 was suppressed after glutamine blocking. More importantly, application of glutamine antagonist in vivo alleviated the progression of IL-23 induced psoriatic mice model. In addition, both the glutamine level and the expression of glutamine related enzymes were found higher in psoriasis patients when compared with healthy controls. Therefore, our work identified an important metabolic regulatory pathway in γδ T cell activation and suggested that glutamine metabolism could be used as a target for the treatment of γδ T cell related diseases.
    Keywords:  Autoimmune disease; Glutamine metabolism; γδ T cell
  2. Cancer Metab. 2021 Jun 25. 9(1): 27
      BACKGROUND: Reprogramming of metabolic pathways is crucial to satisfy the bioenergetic and biosynthetic demands and maintain the redox status of rapidly proliferating cancer cells. In tumors, the tricarboxylic acid (TCA) cycle generates biosynthetic intermediates and must be replenished (anaplerosis), mainly from pyruvate and glutamine. We recently described a novel enolase inhibitor, HEX, and its pro-drug POMHEX. Since glycolysis inhibition would deprive the cell of a key source of pyruvate, we hypothesized that enolase inhibitors might inhibit anaplerosis and synergize with other inhibitors of anaplerosis, such as the glutaminase inhibitor, CB-839.METHODS: We analyzed polar metabolites in sensitive (ENO1-deleted) and resistant (ENO1-WT) glioma cells treated with enolase and glutaminase inhibitors. We investigated whether sensitivity to enolase inhibitors could be attenuated by exogenous anaplerotic metabolites. We also determined the synergy between enolase inhibitors and the glutaminase inhibitor CB-839 in glioma cells in vitro and in vivo in both intracranial and subcutaneous tumor models.
    RESULTS: Metabolomic profiling of ENO1-deleted glioma cells treated with the enolase inhibitor revealed a profound decrease in the TCA cycle metabolites with the toxicity reversible upon exogenous supplementation of supraphysiological levels of anaplerotic substrates, including pyruvate. ENO1-deleted cells also exhibited selective sensitivity to the glutaminase inhibitor CB-839, in a manner rescuable by supplementation of anaplerotic substrates or plasma-like media PlasmaxTM. In vitro, the interaction of these two drugs yielded a strong synergistic interaction but the antineoplastic effects of CB-839 as a single agent in ENO1-deleted xenograft tumors in vivo were modest in both intracranial orthotopic tumors, where the limited efficacy could be attributed to the blood-brain barrier (BBB), and subcutaneous xenografts, where BBB penetration is not an issue. This contrasts with the enolase inhibitor HEX, which, despite its negative charge, achieved antineoplastic effects in both intracranial and subcutaneous tumors.
    CONCLUSION: Together, these data suggest that at least for ENO1-deleted gliomas, tumors in vivo-unlike cells in culture-show limited dependence on glutaminolysis and instead primarily depend on glycolysis for anaplerosis. Our findings reinforce the previously reported metabolic idiosyncrasies of in vitro culture and suggest that cell culture media nutrient composition more faithful to the in vivo environment will more accurately predict in vivo efficacy of metabolism targeting drugs.
    Keywords:  Anaplerosis; CB-839; Cancer metabolism; Collateral lethality; Enolase inhibitor; Glutaminolysis; Glycolysis; POMHEX
  3. FASEB J. 2021 Jul;35(7): e21588
      Ammonia is considered the main pathogenic toxin in hepatic encephalopathy (HE). However, the molecular mechanisms involved have been disputed. As altered glutamatergic and GABAergic neurotransmission has been reported in HE, we investigated whether four members of the solute carrier 38 (Slc38) family of amino acid transporters-involved in the replenishment of glutamate and GABA-contribute to ammonia neurotoxicity in HE. We show that ammonium ion exerts multiple actions on the Slc38 transporters: It competes with glutamine for the binding to the system N transporters Slc38a3 and Slc38a5, consequently inhibiting bidirectional astroglial glutamine transport. It also competes with H+ , Na+ , and K+ for uncoupled permeation through the same transporters, which may perturb astroglial intracellular pH, membrane potential, and K+ -buffering. Knockdown of Slc38a3 in mice results in cerebral cortical edema and disrupted neurotransmitter synthesis mimicking events contributing to HE development. Finally, in a mouse model of acute liver failure (ALF), we demonstrate the downregulation of Slc38a3 protein, impeded astroglial glutamine release, and cytotoxic edema. Altogether, we demonstrate contribution of Slc38 transporters to the ammonia-induced impairment of glutamine recycling between astrocytes and neurons, a phenomenon underlying acute ammonia neurotoxicity in the setting of ALF.
    Keywords:  NH4 + ; SNAT3; Slc38; Slc38a3; hepatic encephalopathy
  4. Dig Dis Sci. 2021 Jun 25.
      BACKGROUND: Glutamine (Gln) is essential for cancer progression, however, few studies have been conducted to investigate the roles of Gln transporters in gastric cancer stem cells (CSCs).AIMS: This work aims to explore the roles of Gln transporters in gastric cancer cell stemness.
    METHODS: We collected spheres formed by gastric cancer (GC) cells through a 3-dimensional (3D) semisolid culture system which has been shown to hold CSC-like traits. Lentivirus package was used to construct GC cells with SNAT2 overexpression. Analysis of sphere-formation, stemness marker expression, ALDH activity were used to detect the effects of Gln transporters on GC cell stemness. Determination of reactive oxygen species (ROS) and Gln consumption combined with the methods analyzing cell stemness were performed to explore the underlying mechanisms.
    RESULTS: Gln consumption was upregulated in GC spheres compared to the parental GC cells. The Gln transporter SNAT2 was highly expressed in GC spheres compared to that in the parental GC cells. SNAT2 overexpression significantly increased the Gln consumption in GC cells and increased the expression of stemness markers, sphere-formation ability and ALDH activity. Notably, SNAT2-mediated promoting effects on GC cell stemness were rescued by Gln deprivation. What's more, high expression of SNAT2 was associated with a poor GC patient survival through different online datasets.
    CONCLUSIONS: SNAT2 can promote the stemness of GC cells in a Gln-dependent manner.
    Keywords:  Cancer stem cell; Gastric cancer; Glutamine; SNAT2; Stemness
  5. iScience. 2021 Jun 25. 24(6): 102649
      Metabolic reprogramming in cancer cells can create metabolic liabilities. KEAP1-mutant lung cancer is refractory to most current therapies. Here we show that KEAP1 deficiency promotes glucose dependency in lung cancer cells, and KEAP1-mutant/deficient lung cancer cells are more vulnerable to glucose deprivation than their WT counterparts. Mechanistically, KEAP1 inactivation in lung cancer cells induces constitutive activation of NRF2 transcription factor and aberrant expression of NRF2 target cystine transporter SLC7A11; under glucose limitation, high cystine uptake in KEAP1-inactivated lung cancer cells stimulates toxic intracellular disulfide buildup, NADPH depletion, and cell death, which can be rescued by genetic ablation of NRF2-SLC7A11 axis or treatments inhibiting disulfide accumulation. Finally, we show that KEAP1-inactivated lung cancer cells or xenograft tumors are sensitive to glucose transporter inhibitor. Together, our results reveal that KEAP1 deficiency induces glucose dependency in lung cancer cells and uncover a therapeutically relevant metabolic liability.
    Keywords:  cancer; cell biology; physiology
  6. Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2021 May 28. pii: 1672-7347(2021)05-0545-07. [Epub ahead of print]46(5): 545-551
      Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) can effectively inhibit the growth of EGFR-dependent mutant non-small cell lung cancer (NSCLC). Unfortunately, NSCLC patients often develop severe drug resistance after long-term EGFR-TKI treatment. Studies have shown that the disorder of energy metabolism in tumor cells can induce EGFR-TKI resistance. Due to the drug action, gene mutation and other factors, tumor cells undergo metabolic reprogramming, which increases the metabolic rate and intensity of tumor cells, promotes the intake and synthesis of nutrients (such as sugar, fat and glutamine), forms a microenvironment conducive to tumor growth, enhances the bypass activation, phenotype transformation and abnormal proliferation of tumor cells, and inhibits the activity of immune cells and apoptosis of tumor cells, ultimately leading to drug resistance of tumor cells to EGFR-TKI. Therefore, targeting energy metabolism of NSCLC may be a potential way to alleviate TKI resistance.
    Keywords:  drug resistance; epiderinal growth factor receptor tyrosine kinase inhibitor; non-small cell lung cancer; tumor metabolism reprogramming
  7. Chem Sci. 2021 Apr 28. 12(22): 7763-7769
      The extraordinarily rapid growth of malignant tumors depends heavily on the glucose metabolism by the pathways of glycolysis and mitochondrial oxidative phosphorylation to generate adenosine 5'-triphosphate (ATP) for maintaining cell proliferation and tumor growth. This study reports a tumor chemical suffocation therapeutic strategy by concurrently suppressing both glycolysis and mitochondrial oxidative phosphorylation (OXPHOS) via the co-deliveries of EDTA and rotenone into a glutathione (GSH)-overexpressed tumor microenvironment. EDTA is to block the glycolytic pathway through inhibiting the activity of glycolytic enzymes via the chelation of magnesium ion, a co-worker of glycolytic enzymes, despite the presence of Ca2+. Meanwhile rotenone is to inhibit the mitochondrial OXPHOS. This work provides a novel tumor suffocation strategy by the co-deliveries of glucose metabolism inhibitors, especially by de-functioning glycolytic enzymes via eliminating their co-worker magnesium.
  8. Commun Biol. 2021 Jun 24. 4(1): 782
      Epithelial-mesenchymal transition (EMT)-a fundamental process in embryogenesis and wound healing-promotes tumor metastasis and resistance to chemotherapy. While studies have identified signaling components and transcriptional factors responsible in the TGF-β-dependent EMT, whether and how intracellular metabolism is integrated with EMT remains to be fully elucidated. Here, we showed that TGF-β induces reprogramming of intracellular amino acid metabolism, which is necessary to promote EMT in non-small cell lung cancer cells. Combined metabolome and transcriptome analysis identified prolyl 4-hydroxylase α3 (P4HA3), an enzyme implicated in cancer metabolism, to be upregulated during TGF-β stimulation. Further, knockdown of P4HA3 diminished TGF-β-dependent changes in amino acids, EMT, and tumor metastasis. Conversely, manipulation of extracellular amino acids induced EMT-like responses without TGF-β stimulation. These results suggest a previously unappreciated requirement for the reprogramming of amino acid metabolism via P4HA3 for TGF-β-dependent EMT and implicate a P4HA3 inhibitor as a potential therapeutic agent for cancer.
  9. Nutr Diabetes. 2021 Jun 23. 11(1): 20
      Defences to pathogens such as SarCoV2 in mammals involves interactions between immune functions and metabolic pathways to eradicate infection while preventing hyperinflammation. Amino acid metabolic pathways represent with other antimicrobial agent potential targets for therapeutic strategies. iNOS-mediated production of NO from Arg is involved in the innate inflammatory response to pathogens and NO overproduction can induce hyperinflammation. The two Arg-catabolising enzymes Arg1 and IDO1 reduce the hyperinflammation by an immunosuppressive effect via either Arg starvation (for Arg1) or via the immunoregulatory activity of the Arg-derived metabolites Kyn (for IDO1). In response to amino acid abundance mTOR activates the host protein translation and Coronaviruses use this machinery for their own protein synthesis and replication. In contrast GCN2, the sensor of amino acid starvation, activates pathways that restrict inflammation and viral replication. Gln depletion alters the immune response that become more suppressive, by favouring a regulatory T phenotype rather than a Th1 phenotype. Proliferating activated immune cells are highly dependent on Ser, activation and differentiation of T cells need enough Ser and dietary Ser restriction can inhibit their proliferation. Cys is strictly required for T-cell proliferation because they cannot convert Met to Cys. Restricting Met inhibits both viral RNA cap methylation and replication, and the proliferation of infected cells with an increased requirement for Met. Phe catabolism produces antimicrobial metabolites resulting in the inhibition of microbial growth and an immunosuppressive activity towards T lymphocytes.
  10. Front Oncol. 2021 ;11 656851
      Metastasis is a major hurdle to the efficient treatment of cancer, accounting for the great majority of cancer-related deaths. Although several studies have disclosed the detailed mechanisms underlying primary tumor formation, the emergence of metastatic disease remains poorly understood. This multistep process encompasses the dissemination of cancer cells to distant organs, followed by their adaptation to foreign microenvironments and establishment in secondary tumors. During the last decades, it was discovered that these events may be favored by particular metabolic patterns, which are dependent on reprogrammed signaling pathways in cancer cells while they acquire metastatic traits. In this review, we present current knowledge of molecular mechanisms that coordinate the crosstalk between metastatic signaling and cellular metabolism. The recent findings involving the contribution of crucial metabolic pathways involved in the bioenergetics and biosynthesis control in metastatic cells are summarized. Finally, we highlight new promising metabolism-based therapeutic strategies as a putative way of impairing metastasis.
    Keywords:  metabolic reprogramming; metastasis; metastatic cascade; new therapies; tumor microenvironment
  11. Ann Transl Med. 2021 May;9(10): 886
      Background: Colorectal cancer (CRC), one of the most common malignancies worldwide, is associated with poor survival and has a high mortality rate. Taxol is a chemotherapeutic agent that has been clinically applied as a first-line drug against diverse cancers. Yet, development of drug resistance has become the major challenge for anti-cancer treatments. F-box and WD40 domain protein 7 (Fbxw7) is a known tumor suppressor which is frequently downregulated in cancers. However, the biological roles and mechanisms of Fbxw7 in Taxol resistance are still under investigation.Methods: We report that Fbxw7 is significantly inactivated in CRC tumors and cell lines compared with normal tissues and colon cells. Expressions of Fbxw7 and Nox1 were detected from human colon tumors and cells by qRT-PCR and Western blot. Glycolysis rate was assessed by glucose uptake and lactate product assay. Interactions between Fbxw7 and Nox1 were determined by co-immunoprecipitation (Co-IP). Chemosensitivity and resistance of colon cancer cells were determined by MTT assay and Annexin V-FITC assay.
    Results: Overexpression of Fbxw7 sensitized colon cancer cells to Taxol. Moreover, we observed a negative correlation between Fbxw7 and glucose metabolism. From the established Taxol-resistant (TR) cell line from HCT-116, Fbxw7 was found to be markedly downregulated in HCT-116 TR cells. We detected that NADPH oxidase 1 (Nox1), a superoxide-generating NADPH oxidase, is negatively regulated by Fbxw7. The Co-IP assay showed that Fbxw7 interacted with Nox1, which was observed to be significantly upregulated in CRC tissues. Nox1 therefore promotes the Taxol resistance and glucose metabolism of colon cancer cells. Finally, rescue experiments demonstrated that the Fbxw7-promoted Taxol sensitivity was partially through the Nox1-glycolysis axis. Restoration of Nox1 in Fbxw7-overexpressed TR colon cancer cells significantly recovered the Taxol resistance, which could be further overridden by glycolysis inhibition.
    Conclusions: Collectively, this study uncovered that targeting the Fbxw7-Nox1-glucose metabolism axis could be an effective strategy against chemoresistant colon cancer.
    Keywords:  Colorectal cancer (CRC); F-box and WD40 domain protein 7 (Fbxw7); NADPH oxidase 1 (Nox1); Taxol sensitivity