bims-glucam 2023-08-27 papers

bims-glucam

Biomed News

on Glutamine cancer metabolism

Issue of 2023–08–27
ten papers selected by
Sreeparna Banerjee, Middle East Technical University

Metabolic reprogramming contributes to radioprotection by protein kinase Cδ.
Metabolic Heterogeneity, Plasticity, and Adaptation to "Glutamine Addiction" in Cancer Cells: The Role of Glutaminase and the GTωA [Glutamine Transaminase-ω-Amidase (Glutaminase II)] Pathway.
SIRT5 Activation and Inorganic Phosphate Binding Reduce Cancer Cell Vitality by Modulating Autophagy/Mitophagy and ROS.
Enhancing the affinity of novel GLS1 allosteric inhibitors by targeting key residue Lys320.
Bioenergetic alteration in gastrointestinal cancers: The good, the bad and the ugly.
Genetics of enzymatic dysfunctions in metabolic disorders and cancer.
Pro-905, a novel purine antimetabolite, combines with glutamine amidotransferase inhibition to suppress growth of malignant peripheral nerve sheath tumor.
Comprehensive isotopomer analysis of glutamate and aspartate in small tissue samples.
Aspartate and Acetate Fuel Gastrointestinal Stromal Tumors Beyond the Warburg Effect.
The pentose phosphate pathway in health and disease.

J Biol Chem. 2023 Aug 21. pii: S0021-9258(23)02214-7. [Epub ahead of print] 105186

Metabolic reprogramming contributes to radioprotection by protein kinase Cδ.

Angela M Ohm, Trisiani Affandi, Julie A Reisz, M Cecilia Caino, Angelo D'Alessandro, Mary E Reyland.

  Loss of protein kinase Cδ (PKCδ) activity renders cells resistant to DNA damaging agents, including irradiation, however the mechanism(s) underlying resistance is poorly understood. Here we have asked if metabolic reprogramming by PKCδ contributes to radioprotection. Analysis of global metabolomics showed that depletion of PKCδ affects metabolic pathways that control energy production, and antioxidant, nucleotide, and amino acid biosynthesis. Increased NADPH and nucleotide production in PKCδ depleted cells is associated with upregulation of the pentose phosphate pathway (PPP) as evidenced by increased activation of G6PD and an increase in the nucleotide precursor, 5-phosphoribosyl-1-pyrophosphate. Stable isotope tracing with U-[13C6] glucose showed reduced utilization of glucose for glycolysis in PKCδ depleted cells, and no increase in U-[13C6] glucose incorporation into purines or pyrimidines. In contrast, isotope tracing with [13C5, 15N2] glutamine showed increased utilization of glutamine for synthesis of nucleotides, glutathione and TCA intermediates, and increased incorporation of labelled glutamine into pyruvate and lactate. Using a glycolytic rate assay, we confirmed that anaerobic glycolysis is increased in PKCδ depleted cells; this was accompanied by a reduction in oxidative phosphorylation, as assayed using a mitochondrial stress assay. Importantly, pretreatment of cells with specific inhibitors of the PPP or glutaminase prior to irradiation reversed radioprotection in PKCδ depleted cells, indicating that these cells have acquired co-dependency on the PPP and glutamine for survival. Our studies demonstrate that metabolic reprogramming to increase utilization of glutamine and nucleotide synthesis contributes to radioprotection in the context of PKCδ inhibition.

Keywords:  apoptosis; metabolism; protein kinase Cδ; radioprotection; salivary gland

DOI:  https://doi.org/10.1016/j.jbc.2023.105186
Biology (Basel). 2023 Aug 14. pii: 1131. [Epub ahead of print]12(8):

Metabolic Heterogeneity, Plasticity, and Adaptation to "Glutamine Addiction" in Cancer Cells: The Role of Glutaminase and the GTωA [Glutamine Transaminase-ω-Amidase (Glutaminase II)] Pathway.

Arthur J L Cooper, Thambi Dorai, John T Pinto, Travis T Denton.

  Many cancers utilize l-glutamine as a major energy source. Often cited in the literature as "l-glutamine addiction", this well-characterized pathway involves hydrolysis of l-glutamine by a glutaminase to l-glutamate, followed by oxidative deamination, or transamination, to α-ketoglutarate, which enters the tricarboxylic acid cycle. However, mammalian tissues/cancers possess a rarely mentioned, alternative pathway (the glutaminase II pathway): l-glutamine is transaminated to α-ketoglutaramate (KGM), followed by ω-amidase (ωA)-catalyzed hydrolysis of KGM to α-ketoglutarate. The name glutaminase II may be confused with the glutaminase 2 (GLS2) isozyme. Thus, we recently renamed the glutaminase II pathway the "glutamine transaminase-ω-amidase (GTωA)" pathway. Herein, we summarize the metabolic importance of the GTωA pathway, including its role in closing the methionine salvage pathway, and as a source of anaplerotic α-ketoglutarate. An advantage of the GTωA pathway is that there is no net change in redox status, permitting α-ketoglutarate production during hypoxia, diminishing cellular energy demands. We suggest that the ability to coordinate control of both pathways bestows a metabolic advantage to cancer cells. Finally, we discuss possible benefits of GTωA pathway inhibitors, not only as aids to studying the normal biological roles of the pathway but also as possible useful anticancer agents.

Keywords:  GLS1; GLS2; GTωA pathway; asparaginase; asparaginase II pathway; glutaminase II; glutamine transaminase; l-glutamate; l-glutamine; l-glutamine addiction; α-ketoglutaramate; α-ketoglutarate; α-ketosuccinamate; ω-amidase

DOI:  https://doi.org/10.3390/biology12081131
Antioxidants (Basel). 2023 Aug 18. pii: 1635. [Epub ahead of print]12(8):

SIRT5 Activation and Inorganic Phosphate Binding Reduce Cancer Cell Vitality by Modulating Autophagy/Mitophagy and ROS.

Federica Barreca, Michele Aventaggiato, Laura Vitiello, Luigi Sansone, Matteo Antonio Russo, Antonello Mai, Sergio Valente, Marco Tafani.

  Cancer cells show increased glutamine consumption. The glutaminase (GLS) enzyme controls a limiting step in glutamine catabolism. Breast tumors, especially the triple-negative subtype, have a high expression of GLS. Our recent study demonstrated that GLS activity and ammonia production are inhibited by sirtuin 5 (SIRT5). We developed MC3138, a selective SIRT5 activator. Treatment with MC3138 mimicked the deacetylation effect mediated by SIRT5 overexpression. Moreover, GLS activity was regulated by inorganic phosphate (Pi). Considering the interconnected roles of GLS, SIRT5 and Pi in cancer growth, our hypothesis is that activation of SIRT5 and reduction in Pi could represent a valid antitumoral strategy. Treating cells with MC3138 and lanthanum acetate, a Pi chelator, decreased cell viability and clonogenicity. We also observed a modulation of MAP1LC3B and ULK1 with MC3138 and lanthanum acetate. Interestingly, inhibition of the mitophagy marker BNIP3 was observed only in the presence of MC3138. Autophagy and mitophagy modulation were accompanied by an increase in cytosolic and mitochondrial reactive oxygen species (ROS). In conclusion, our results show how SIRT5 activation and/or Pi binding can represent a valid strategy to inhibit cell proliferation by reducing glutamine metabolism and mitophagy, leading to a deleterious accumulation of ROS.

Keywords:  ROS; autophagy; glutaminase; glutamine; hypoxia; mitophagy; sirtuins

DOI:  https://doi.org/10.3390/antiox12081635
Future Med Chem. 2023 Aug 23.

Enhancing the affinity of novel GLS1 allosteric inhibitors by targeting key residue Lys320.

Li Zhu, Xiujin Chang, Shengpeng Zhang, Xiumei Bai, Alexander V Finko, Xi Xu, Jinlei Bian, Xiaoping Liu, Huidan Huang.

  Aim: A series of novel GLS1 irreversible allosteric inhibitors targeting Lys320 might have robust enzyme inhibitory activity and potent antitumor activity. Materials & methods: Novel GLS1 allosteric inhibitors targeting Lys320 were synthesized and their anticancer activity was assessed. Moreover, GLS1 protein was used as a model system to analyze the reactivity of these electrophilic groups in GLS1 irreversible allosteric inhibitors with other amino acids, including tyrosine, histidine, serine and threonine, using biochemical and biophysical assays. Results: AC16 exhibited robust GLS1 inhibitory activity, antiproliferative effect in vitro, good plasma stability and potential covalent addition with GLS1 K320. Conclusion: This study opens a novel avenue for the design of robust irreversible GLS1 inhibitors targeting the allosteric site K320.

Keywords:  GLS1; allosteric; glutamine metabolism; irreversible; lysine

DOI:  https://doi.org/10.4155/fmc-2023-0114
World J Gastroenterol. 2023 Aug 07. 29(29): 4499-4527

Bioenergetic alteration in gastrointestinal cancers: The good, the bad and the ugly.

Yu-De Chu, Chun-Wei Chen, Ming-Wei Lai, Siew-Na Lim, Wey-Ran Lin.

  Cancer cells exhibit metabolic reprogramming and bioenergetic alteration, utilizing glucose fermentation for energy production, known as the Warburg effect. However, there are a lack of comprehensive reviews summarizing the metabolic reprogramming, bioenergetic alteration, and their oncogenetic links in gastrointestinal (GI) cancers. Furthermore, the efficacy and treatment potential of emerging anticancer drugs targeting these alterations in GI cancers require further evaluation. This review highlights the interplay between aerobic glycolysis, the tricarboxylic acid (TCA) cycle, and oxidative phosphorylation (OXPHOS) in cancer cells, as well as hypotheses on the molecular mechanisms that trigger this alteration. The role of hypoxia-inducible transcription factors, tumor suppressors, and the oncogenetic link between hypoxia-related enzymes, bioenergetic changes, and GI cancer are also discussed. This review emphasizes the potential of targeting bioenergetic regulators for anti-cancer therapy, particularly for GI cancers. Emphasizing the potential of targeting bioenergetic regulators for GI cancer therapy, the review categorizes these regulators into aerobic glycolysis/ lactate biosynthesis/transportation and TCA cycle/coupled OXPHOS. We also detail various anti-cancer drugs and strategies that have produced pre-clinical and/or clinical evidence in treating GI cancers, as well as the challenges posed by these drugs. Here we highlight that understanding dysregulated cancer cell bioenergetics is critical for effective treatments, although the diverse metabolic patterns present challenges for targeted therapies. Further research is needed to comprehend the specific mechanisms of inhibiting bioenergetic enzymes, address side effects, and leverage high-throughput multi-omics and spatial omics to gain insights into cancer cell heterogeneity for targeted bioenergetic therapies.

Keywords:  Energy metabolism; Gastrointestinal neoplasms; Glycolysis; Hypoxia; Mitochondria; Oxidative phosphorylation

DOI:  https://doi.org/10.3748/wjg.v29.i29.4499
Front Oncol. 2023 ;13 1230934

Genetics of enzymatic dysfunctions in metabolic disorders and cancer.

Mélanie Mahé, Tiffany J Rios-Fuller, Andrea Karolin, Robert J Schneider.

  Inherited metabolic disorders arise from mutations in genes involved in the biogenesis, assembly, or activity of metabolic enzymes, leading to enzymatic deficiency and severe metabolic impairments. Metabolic enzymes are essential for the normal functioning of cells and are involved in the production of amino acids, fatty acids and nucleotides, which are essential for cell growth, division and survival. When the activity of metabolic enzymes is disrupted due to mutations or changes in expression levels, it can result in various metabolic disorders that have also been linked to cancer development. However, there remains much to learn regarding the relationship between the dysregulation of metabolic enzymes and metabolic adaptations in cancer cells. In this review, we explore how dysregulated metabolism due to the alteration or change of metabolic enzymes in cancer cells plays a crucial role in tumor development, progression, metastasis and drug resistance. In addition, these changes in metabolism provide cancer cells with a number of advantages, including increased proliferation, resistance to apoptosis and the ability to evade the immune system. The tumor microenvironment, genetic context, and different signaling pathways further influence this interplay between cancer and metabolism. This review aims to explore how the dysregulation of metabolic enzymes in specific pathways, including the urea cycle, glycogen storage, lysosome storage, fatty acid oxidation, and mitochondrial respiration, contributes to the development of metabolic disorders and cancer. Additionally, the review seeks to shed light on why these enzymes represent crucial potential therapeutic targets and biomarkers in various cancer types.

Keywords:  cancer; enzymatic dysregulation; fatty acid oxidation; glycogen storage; inherited metabolic disorders; lysosome storage; mitochondrial respiration; urea cycle

DOI:  https://doi.org/10.3389/fonc.2023.1230934
Mol Cancer Ther. 2023 Aug 24. pii: MCT-23-0258. [Epub ahead of print]

Pro-905, a novel purine antimetabolite, combines with glutamine amidotransferase inhibition to suppress growth of malignant peripheral nerve sheath tumor.

Kathryn M Lemberg, Eunus S Ali, Marcela Krecmerova, Joanna Marie H Aguilar, Jesse Alt, Diane E Peters, Liang Zhao, Ying Wu, Naziba Nuha, John M Asara, Verena Staedtke, Christine A Pratilas, Pavel Majer, Rana Rais, Issam Ben-Sahra, Barbara S Slusher.

Malignant peripheral nerve sheath tumors (MPNST) are highly aggressive soft tissue sarcomas that arise from neural tissues and carry a poor prognosis. Previously, we found that the glutamine amidotransferase (GA) inhibitor JHU395 partially impeded tumor growth in preclinical models of MPNST. JHU395 inhibits de novo purine synthesis in human MPNST cells and murine tumors with partial decreases in purine monophosphates. Based on prior studies showing enhanced efficacy when GA inhibition was combined with the antimetabolite 6-mercaptopurine (6-MP), we hypothesized that such a combination would be efficacious in MPNST. Given the known toxicity associated with 6-MP, we set out to develop a more efficient and well-tolerated drug that targets the purine salvage pathway. Here, we report the discovery of Pro-905, a phosphoramidate protide that delivered the active nucleotide antimetabolite thioguanosine monophosphate (TGMP) to tumors over 2.5 times better than equimolar 6-MP. Pro-905 effectively prevented the incorporation of purine salvage substrates into nucleic acids and inhibited colony formation of human MPNST cells in a dose-dependent manner. Additionally, Pro-905 inhibited MPNST growth and was well-tolerated in both human patient-derived xenograft and murine flank MPNST models. When combined with JHU395, Pro-905 enhanced the colony formation inhibitory potency of JHU395 in human MPNST cells and augmented the antitumor efficacy of JHU395 in mice. In summary, the dual inhibition of the de novo and purine salvage pathways in preclinical models may safely be used to enhance therapeutic efficacy against MPNST.

DOI: https://doi.org/10.1158/1535-7163.MCT-23-0258
Cell Metab. 2023 Aug 15. pii: S1550-4131(23)00272-3. [Epub ahead of print]

Comprehensive isotopomer analysis of glutamate and aspartate in small tissue samples.

Feng Cai, Divya Bezwada, Ling Cai, Rohit Mahar, Zheng Wu, Mario C Chang, Panayotis Pachnis, Chendong Yang, Sherwin Kelekar, Wen Gu, Bailey Brooks, Bookyung Ko, Hieu S Vu, Thomas P Mathews, Lauren G Zacharias, Misty Martin-Sandoval, Duyen Do, K Celeste Oaxaca, Eunsook S Jin, Vitaly Margulis, Craig R Malloy, Matthew E Merritt, Ralph J DeBerardinis.

  Stable isotopes are powerful tools to assess metabolism. 13C labeling is detected using nuclear magnetic resonance (NMR) spectroscopy or mass spectrometry (MS). MS has excellent sensitivity but generally cannot discriminate among different 13C positions (isotopomers), whereas NMR is less sensitive but reports some isotopomers. Here, we develop an MS method that reports all 16 aspartate and 32 glutamate isotopomers while requiring less than 1% of the sample used for NMR. This method discriminates between pathways that result in the same number of 13C labels in aspartate and glutamate, providing enhanced specificity over conventional MS. We demonstrate regional metabolic heterogeneity within human tumors, document the impact of fumarate hydratase (FH) deficiency in human renal cancers, and investigate the contributions of tricarboxylic acid (TCA) cycle turnover and CO2 recycling to isotope labeling in vivo. This method can accompany NMR or standard MS to provide outstanding sensitivity in isotope-labeling experiments, particularly in vivo.

Keywords:  aspartate; cancer; glutamate; isotopomer; mass spectrometry; nuclear magnetic resonance; pyruvate carboxylase; stable isotope; tricarboxylic acid cycle

DOI:  https://doi.org/10.1016/j.cmet.2023.07.013
Ann Surg Open. 2022 Dec;3(4): e224

Aspartate and Acetate Fuel Gastrointestinal Stromal Tumors Beyond the Warburg Effect.

Ying-Chieh Lai, Gigin Lin, Kung-Chu Ho, Kuan-Ying Lu, Cheng-Kun Tsai, Cheng-Yu Hung, Ta-Sen Yeh.

  Metabolic reprogramming is closely linked to the tumorigenesis and drug resistance of gastrointestinal stromal tumors (GISTs). Mapping the metabolic orbit of GISTs is a prerequisite if intervention against the metabolic vulnerability of refractory GISTs is desirable.
Methods: A total of 43 patients with treatment-naïve GISTs who had undergone surgical resections were enrolled, on whom a metabolomics profile detected from surgical specimens was constructed based on the 1H-nuclear magnetic resonance (NMR) platform. The mRNA and protein levels of GLUT1, HK2, ACSS2, and FASN were assayed. Dual-tracer 18F-FDG/11C-acetate PET imaging was introduced before surgery in 15 patients.
Results: 1H-NMR-based metabolomics revealed that GISTs were characterized by upregulation of glutamate, ascorbate, aspartate and glycine and downregulation of choline, creatine, glucose and glycerol. Bioinformatics analysis showed that the TCA cycle and alanine, aspartate, and glutamate metabolism were the two leading pathways. High- and nonhigh-risk (including intermediate-, low-, and very low-risk) GISTs preferentially displayed upregulation of HK2 and ACSS2, respectively, echoed by in vivo imaging that high- and nonhigh-risk GISTs preferentially exhibited higher uptake of 18F-FDG and 11C-acetate, respectively, while 18F-FDG and 11C-acetate were complementary to each other. Nuclear ACSS2 was exclusively identified in high-risk GISTs.
Conclusion: We describe a metabolic landscape of GISTs that read aspartate as a de facto "oncometabolite," which was replenished via the TCA cycle and alanine, aspartate, and glutamate metabolism. Glycolysis and ACSS2-mediated acetate metabolism competed and complemented fatty acid synthesis, although glycolysis remained an aggressive phenotype.

Keywords:  TCA cycle; Warburg effect; acetate; aspartate; gastrointestinal stromal tumor; metabolomics

DOI:  https://doi.org/10.1097/AS9.0000000000000224
Nat Metab. 2023 Aug;5(8): 1275-1289

The pentose phosphate pathway in health and disease.

Tara TeSlaa, Markus Ralser, Jing Fan, Joshua D Rabinowitz.

The pentose phosphate pathway (PPP) is a glucose-oxidizing pathway that runs in parallel to upper glycolysis to produce ribose 5-phosphate and nicotinamide adenine dinucleotide phosphate (NADPH). Ribose 5-phosphate is used for nucleotide synthesis, while NADPH is involved in redox homoeostasis as well as in promoting biosynthetic processes, such as the synthesis of tetrahydrofolate, deoxyribonucleotides, proline, fatty acids and cholesterol. Through NADPH, the PPP plays a critical role in suppressing oxidative stress, including in certain cancers, in which PPP inhibition may be therapeutically useful. Conversely, PPP-derived NADPH also supports purposeful cellular generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) for signalling and pathogen killing. Genetic deficiencies in the PPP occur relatively commonly in the committed pathway enzyme glucose-6-phosphate dehydrogenase (G6PD). G6PD deficiency typically manifests as haemolytic anaemia due to red cell oxidative damage but, in severe cases, also results in infections due to lack of leucocyte oxidative burst, highlighting the dual redox roles of the pathway in free radical production and detoxification. This Review discusses the PPP in mammals, covering its roles in biochemistry, physiology and disease.

DOI: https://doi.org/10.1038/s42255-023-00863-2