bims-glucam 2024-11-17 papers

bims-glucam

Biomed News

on Glutamine cancer metabolism

Issue of 2024–11–17
24 papers selected by
Sreeparna Banerjee, Middle East Technical University

Glioblastoma Sensitization to Therapeutic Effects by Glutamine Deprivation Depends on Cellular Phenotype and Metabolism.
Deciphering the Metabolic Basis and Molecular Circuitry of the Warburg Paradox in Lymphoma.
GlutaR: A High-Performance Fluorescent Protein-Based Sensor for Spatiotemporal Monitoring of Glutamine Dynamics In Vivo.
A glutamine metabolic switch supports erythropoiesis.
ω-Amidase and Its Substrate α-Ketoglutaramate (the α-Keto Acid Analogue of Glutamine) as Biomarkers in Health and Disease.
The Role of Dicer Phosphorylation in Gemcitabine Resistance of Pancreatic Cancer.
Nutritional Glutamine-Modified Iron-Delivery System with Enhanced Endocytosis for Ferroptosis Therapy of Pancreatic Tumors.
DON encapsulated carbon dot-vesicle conjugate in therapeutic intervention of lung adenocarcinoma by dual targeting of CD44 and SLC1A5.
LINC01764 promotes colorectal cancer cells proliferation, metastasis, and 5-fluorouracil resistance by regulating glucose and glutamine metabolism via promoting c-MYC translation.
NRF2 signaling and amino acid metabolism in cancer.
Contribution of glucose and glutamine to hypoxia-induced lipid synthesis decreases, while contribution of acetate increases, during 3T3-L1 differentiation.
Genome-Scale Modeling of CHO Cells Unravel the Critical Role of Asparagine in Cell Culture Feed Media.
Hydroxyacid Oxidase 1, a Glutamine Metabolism-Associated Protein, Predicts Poor Patient Outcome in Luminal Breast Cancer.
Impact of metabolism-related markers on outcomes in ovarian cancer patients: Findings of the MITO16A/MaNGO-OV2 trial.
Prolonged glutamine starvation reactivates mTOR to inhibit autophagy and initiate autophagic lysosome reformation to maintain cell viability.
SLC38A5 suppresses ferroptosis through glutamine-mediated activation of the PI3K/AKT/mTOR signaling in osteosarcoma.
Targeting Cancer Metabolism as a New Strategy to Enhance Treatment Efficacy and Overcome Resistance.
Targeting glutamine synthetase with AS1411-modified exosome-liposome hybrid nanoparticles for inhibition of choroidal neovascularization.
Glutathione and Selenium Supplementation Attenuates Liver Injury in Diethylnitrosamine-Induced Hepatocarcinogenic Mice by Enhancing Glutathione-Related Antioxidant Capacities.
SNF2L maintains glutathione homeostasis by initiating SLC7A11 transcription through chromatin remodeling.
LncRNAs in tumor metabolic reprogramming and tumor microenvironment remodeling.
The Glutamine Synthetases Are Required for Sensory Hair Cell Formation and Auditory Function in Zebrafish.
Measuring 15N and 13C Enrichment Levels in Sparsely Labeled Proteins Using High-Resolution and Tandem Mass Spectrometry.
Dual-locked NIR fluorescent probe for detection of GSH and lipid droplets and its bioimaging application in cancer model.

Biochemistry (Mosc). 2024 Oct;89(10): 1744-1758

Glioblastoma Sensitization to Therapeutic Effects by Glutamine Deprivation Depends on Cellular Phenotype and Metabolism.

Alina A Isakova, Irina N Druzhkova, Artem M Mozherov, Diana V Mazur, Nadezhda V Antipova, Kirill S Krasnov, Roman S Fadeev, Marine E Gasparian, Anne V Yagolovich.

  Glutamine plays an important role in tumor metabolism. It is known that the core region of solid tumors is deprived of glutamine, which affects tumor growth and spread. Here we investigated the effect of glutamine deprivation on cellular metabolism and sensitivity of human glioblastoma cells U87MG and T98G to drugs of various origin: alkylating cytostatic agent temozolomide; cytokine TRAIL DR5-B - agonist of the DR5 receptor; and GMX1778 - a targeted inhibitor of the enzyme nicotinamide phosphoribosyltransferase (NAMPT), limiting NAD biosynthesis. Bioinformatics analysis of the cell transcriptomes showed that U87MG cells have a more differentiated phenotype than T98G, and also differ in the expression profile of the genes associated with glutamine metabolism. Upon glutamine deprivation, growth rate of the U87MG and T98G cells decreased. Analysis of cellular metabolism by FLIM microscopy of NADH as well as assessment of lactate content in the medium showed that glutamine deprivation shifted metabolic status of the U87MG cells towards glycolysis. This was accompanied by the increase in expression of the stemness marker CD133, which collectively could indicate de-differentiation of these cells. At the same time, we observed increase in both expression of the DR5 receptor and sensitivity of the U87MG cells to DR5-B. On the contrary, glutamine deprivation of T98G cells induced metabolic shift towards oxidative phosphorylation, decrease in the DR5 expression and resistance to DR5-B. The effects of NAMPT inhibition also differed between the two cell lines and were opposite to the effects of DR5-B: upon glutamine deprivation, U87MG cells acquired resistance, while T98G cells were sensitized to GMX1778. Thus, phenotypic and metabolic differences between the two human glioblastoma cell lines caused divergent metabolic changes and contrasting responses to different targeted drugs during glutamine deprivation. These data should be considered when developing treatment strategies for glioblastoma via drug-mediated deprivation of amino acids, as well as when exploring novel therapeutic targets.

Keywords:  CD133; DR5; FLIM microscopy; GMX1778; NAD(P)H; NAMPT; TRAIL; cell differentiation; glioblastoma; glutamine deprivation

DOI:  https://doi.org/10.1134/S0006297924100079
Cancers (Basel). 2024 Oct 25. pii: 3606. [Epub ahead of print]16(21):

Deciphering the Metabolic Basis and Molecular Circuitry of the Warburg Paradox in Lymphoma.

Dashnamoorthy Ravi, Athena Kritharis, Andrew M Evens.

  Background/Objectives: Warburg's metabolic paradox illustrates that malignant cells require both glucose and oxygen to survive, even after converting glucose into lactate. It remains unclear whether sparing glucose from oxidation intersects with TCA cycle continuity and if this confers any metabolic advantage in proliferating cancers. This study seeks to understand the mechanistic basis of Warburg's paradox and its overall implications for lymphomagenesis. Methods: Using metabolomics, we first examined the metabolomic profiles, glucose, and glutamine carbon labeling patterns in the metabolism during the cell cycle. We then investigated proliferation-specific metabolic features of malignant and nonmalignant cells. Finally, through bioinformatics and the identification of appropriate pharmacological targets, we established malignant-specific proliferative implications for the Warburg paradox associated with metabolic features in this study. Results: Our results indicate that pyruvate, lactate, and alanine levels surge during the S phase and are correlated with nucleotide synthesis. By using 13C1,2-Glucose and 13C6,15N2-Glutamine isotope tracers, we observed that the transamination of pyruvate to alanine is elevated in lymphoma and coincides with the entry of glutamine carbon into the TCA cycle. Finally, by using fludarabine as a strong inhibitor of lymphoma, we demonstrate that disrupting the transamination of pyruvate to alanine correlates with the simultaneous suppression of glucose-derived nucleotide biosynthesis and glutamine carbon entry into the TCA cycle. Conclusions: We conclude that the transamination of pyruvate to alanine intersects with reduced glucose oxidation and maintains the TCA cycle as a critical metabolic feature of Warburg's paradox and lymphomagenesis.

Keywords:  Warburg effect; glucose; glutamine; lactate; lymphoma; nucleotides; targeted inhibitors; transaminase

DOI:  https://doi.org/10.3390/cancers16213606
Angew Chem Int Ed Engl. 2024 Nov 13. e202416608

GlutaR: A High-Performance Fluorescent Protein-Based Sensor for Spatiotemporal Monitoring of Glutamine Dynamics In Vivo.

Bingjie Liu, Zijie Zhao, Pengcheng Wang, Kamiran Aihemaiti, Lixin Zhu, Qingpeng Wei, Wenzhe Li, Xia Yuan, Jing Wu, Changtao Jiang, Min Hao, Jing Wang.

  Glutamine is the most abundant amino acid in human blood and muscle, and is integral to a wide variety of functions in cancer cells. However, the inability to monitor the subcellular distribution of glutamine in real-time has obscured understanding of glutamine metabolism under physiological and pathological conditions. Here, we report the development of a genetically encoded fluorescent sensor and demonstrate how this GlnBP-cpYFP fusion "GlutaR sensor" undergoes glutamine-induced conformational changes reflected in detectable fluorescence responses. Obtained after iterative screening of approximately 1,600 variants, GlutaR exhibits a ratiometric readout, fast response kinetics, and high responsivity, and we demonstrate its selectivity for monitoring glutamine fluctuations in multiple cell types. Additionally, using digitonin permeabilization of GlutaR HeLa cells, we generated a calibration curve and performed in situ titration to quantify free glutamine concentrations in subcellular compartments (cytosol, nucleus, mitochondria). Subsequently, we applied GlutaR to investigate how chemical and genetic inhibition of GS and GLS differentially alter glutamine levels in subcellular compartments. Finally, we demonstrate GlutaR's ability to monitor dynamic glutamine levels in muscle and liver tissues of diabetic mice in vivo. These findings collectively demonstrate GlutaR as a versatile tool for the spatiotemporal characterization of glutamine metabolism in living cells and tissues.

Keywords:  glutamine* biosensor* fluorescence imaging * metabolism* live mice

DOI:  https://doi.org/10.1002/anie.202416608
Science. 2024 Nov 15. 386(6723): eadh9215

A glutamine metabolic switch supports erythropoiesis.

Junhua Lyu, Zhimin Gu, Yuannyu Zhang, Hieu S Vu, Christophe Lechauve, Feng Cai, Hui Cao, Julia Keith, Valentina Brancaleoni, Francesca Granata, Irene Motta, Maria Domenica Cappellini, Lily Jun-Shen Huang, Ralph J DeBerardinis, Mitchell J Weiss, Min Ni, Jian Xu.

Metabolic requirements vary during development, and our understanding of how metabolic activity influences cell specialization is incomplete. Here, we describe a switch from glutamine catabolism to synthesis required for erythroid cell maturation. Glutamine synthetase (GS), one of the oldest functioning genes in evolution, is activated during erythroid maturation to detoxify ammonium generated from heme biosynthesis, which is up-regulated to support hemoglobin production. Loss of GS in mouse erythroid precursors caused ammonium accumulation and oxidative stress, impairing erythroid maturation and recovery from anemia. In β-thalassemia, GS activity is inhibited by protein oxidation, leading to glutamate and ammonium accumulation, whereas enhancing GS activity alleviates the metabolic and pathological defects. Our findings identify an evolutionarily conserved metabolic adaptation that could potentially be leveraged to treat common red blood cell disorders.

DOI: https://doi.org/10.1126/science.adh9215
Biochemistry (Mosc). 2024 Oct;89(10): 1660-1680

ω-Amidase and Its Substrate α-Ketoglutaramate (the α-Keto Acid Analogue of Glutamine) as Biomarkers in Health and Disease.

Arthur J L Cooper, Travis T Denton.

  A large literature exists on the biochemistry, chemistry, metabolism, and clinical importance of the α-keto acid analogues of many amino acids. However, although glutamine is the most abundant amino acid in human tissues, and transamination of glutamine to its α-keto acid analogue (α-ketoglutaramate; KGM) was described more than seventy years ago, little information is available on the biological importance of KGM. Herein, we summarize the metabolic importance of KGM as an intermediate in the glutamine transaminase - ω-amidase (GTωA) pathway for the conversion of glutamine to anaplerotic α-ketoglutarate. We describe some properties of KGM, notably its occurrence as a lactam (2-hydroxy-5-oxoproline; 99.7% at pH 7.2), and its presence in normal tissues and body fluids. We note that the concentration of KGM is elevated in the cerebrospinal fluid of liver disease patients and that the urinary KGM/creatinine ratio is elevated in patients with an inborn error of the urea cycle and in patients with citrin deficiency. Recently, of the 607 urinary metabolites measured in a kidney disease study, KGM was noted to be one of five metabolites that was most significantly associated with uromodulin (a potential biomarker for tubular functional mass). Finally, we note that KGM is an intermediate in the breakdown of nicotine in certain organisms and is an important factor in nitrogen homeostasis in some microorganisms and plants. In conclusion, we suggest that biochemists and clinicians should consider KGM as (i) a key intermediate in nitrogen metabolism in all branches of life, and (ii) a biomarker, along with ω-amidase, in several diseases.

Keywords:  2-hydroxy-5-oxoproline; ammonia; anaplerosis; glutaminase 1; glutaminase 2; glutamine; glutamine addiction; glutamine transaminases; hyperammonemia; methionine; methionine salvage pathway; transamination; α-ketoglutaramate; α-ketoglutarate; ω-amidase

DOI:  https://doi.org/10.1134/S000629792410002X
Int J Mol Sci. 2024 Nov 02. pii: 11797. [Epub ahead of print]25(21):

The Role of Dicer Phosphorylation in Gemcitabine Resistance of Pancreatic Cancer.

Ching-Feng Chiu, Hui-Ru Lin, Yen-Hao Su, Hsin-An Chen, Shao-Wen Hung, Shih-Yi Huang.

  Dicer, a cytoplasmic type III RNase, is essential for the maturation of microRNAs (miRNAs) and is implicated in cancer progression and chemoresistance. Our previous research demonstrated that phosphorylation of Dicer at S1016 alters miRNA maturation and glutamine metabolism, contributing to gemcitabine (GEM) resistance in pancreatic ductal adenocarcinoma (PDAC). In this study, we focused on the role of Dicer phosphorylation at S1728/S1852 in GEM-resistant PDAC cells. Using shRNA to knock down Dicer in GEM-resistant PANC-1 (PANC-1 GR) cells, we examined cell viability through MTT and clonogenic assays. We also expressed phosphomimetic Dicer 2E (S1728E/S1852E) and phosphomutant Dicer 2A (S1728A/S1852A) to evaluate their effects on GEM resistance and metabolism. Our results show that phosphorylation at S1728/S1852 promotes GEM resistance by reprogramming glutamine metabolism. Specifically, phosphomimetic Dicer 2E increased intracellular glutamine, driving pyrimidine synthesis and raising dCTP levels, which compete with gemcitabine's metabolites. This metabolic shift enhanced drug resistance. In contrast, phosphomutant Dicer 2A reduced GEM resistance. These findings highlight the importance of Dicer phosphorylation in regulating metabolism and drug sensitivity, offering insights into potential therapeutic strategies for overcoming GEM resistance in pancreatic cancer.

Keywords:  gemcitabine; glutamine; microRNA; pancreatic ductal adenocarcinoma; phosphorylated Dicer

DOI:  https://doi.org/10.3390/ijms252111797
ACS Nano. 2024 Nov 08.

Nutritional Glutamine-Modified Iron-Delivery System with Enhanced Endocytosis for Ferroptosis Therapy of Pancreatic Tumors.

Yang Chen, Wenzhe Xu, Hao Jin, Mengsi Zhang, Shuwei Liu, Yi Liu, Hao Zhang.

  Heterogeneous reprogrammed nutrient metabolic networks formed by oncogenes exhibit the potential for exploring novel druggable targets and developing innovative anticancer therapeutics. Herein, based on the heterogeneous metabolic characteristics of glutamine (Gln) addiction in pancreatic cancer cells, an iron-delivery system (IDS) with enhanced endocytosis is designed for efficient ferroptosis therapy. The IDS is characterized by Gln modification and can be recognized as a source of Gln nutrients for efficient endocytic uptake by pancreatic tumor cells. Because the IDS is flexible to combine with amino acid-like components, the IDS with enhanced endocytosis is further produced by loading the Gln transporter inhibitor of V9302. V9302 is capable of suppressing molecular Gln uptake via transporter ASCT2, which generates Gln deprivation to direct metabolic reprogramming of cancer cells and enhances cellular uptake of Gln-modified IDS via RAS-stimulated macropinocytosis. The enhanced endocytosis and high iron content of IDS facilitate ferroptosis in mice pancreatic tumor models; thus, an amino acid-like ferroptosis inducer of l-buthionine sulfoximine (BSO) is further combined. The enhanced endocytosis resulting from the synergism of Gln and V9302 enables the efficient delivery of iron and BSO for ferroptosis tumor therapy. This work provides an alternative approach for enhancing intracellular drug delivery of the tumors with heterogeneous nutrient metabolism by virtue of combining nutrient-modified nanodrugs with the corresponding nutrient transporter inhibitors.

Keywords:  endocytosis; ferroptosis; glutamine; iron-delivery system; metabolism; nutrient acquisition; pancreatic cancer

DOI:  https://doi.org/10.1021/acsnano.4c08083
Nanoscale. 2024 Nov 08.

DON encapsulated carbon dot-vesicle conjugate in therapeutic intervention of lung adenocarcinoma by dual targeting of CD44 and SLC1A5.

Afreen Zaman, Aparajita Ghosh, Anup Kumar Ghosh, Prasanta Kumar Das.

Lung adenocarcinoma, recognized as one of the most formidable malignancies with a dismal prognosis and low survival rates, poses a significant challenge in its treatment. This article delineates the design and development of a carbon dot-vesicle conjugate (HACD-TMAV) for efficient cytotoxicity towards lung cancer cells by target selective delivery of the glutamine inhibitor 6-diazo-5-oxo-L-norleucine (DON) within CD44-enriched A549 cancer cells. HACD-TMAV is composed of hyaluronic acid-based carbon dots (HACDs) and trimesic acid-based vesicles (TMAV), which are bound via electrostatic interactions. TMAVs are formed by positively charged trimesic acid-based amphiphiles through H-type aggregation in water. HACDs were synthesized through a one-step hydrothermal route. The blue-emitting HACD-TMAV conjugate demonstrated selective bioimaging in CD44-overexpressed A549 lung cancer cells due to specific ligand-receptor interactions between HA and CD44. HACD-TMAV exhibited notably improved DON loading efficiency compared to individual nano-vehicles. HACD-TMAV-DON exhibited remarkable (∼6.0-fold higher) cytotoxicity against CD44-overexpressing A549 cells compared to CD44- HepG2 cells and HEK 293 normal cells. Also, DON-loaded HACD-TMAV showed ∼2.0-fold higher cytotoxicity against A549 cells compared to individual carriers and ∼4.5-fold higher cytotoxicity than by DON. Furthermore, HACD-TMAV-DON induced a ∼3.5-fold reduction in the size of 3D tumor spheroids of A549 cells. The enhanced anticancer effectiveness was attributed to starvation of the A549 cells of glutamine by dual targeting of glutamine metabolism and solute linked carrier family 1 member A5 (SLC1A5) through HA-linked CD44-mediated targeted delivery of DON. This led to over-production of reactive oxygen species (ROS) that induced apoptosis of cancer cells through downregulation of the PI3K/AKT/mTOR signaling cascade.

DOI: https://doi.org/10.1039/d4nr00426d
MedComm (2020). 2024 Nov;5(11): e70003

LINC01764 promotes colorectal cancer cells proliferation, metastasis, and 5-fluorouracil resistance by regulating glucose and glutamine metabolism via promoting c-MYC translation.

Ran Duan, Yujia Zhai, Qiushuang Wang, Liqin Zhao, Yixuan Wang, Nuoya Yu, Jieyun Zhang, Weijian Guo.

  Few biomarkers are available for predicting chemotherapeutic response and prognosis in colorectal cancer (CRC). Long-noncoding RNAs (lncRNAs) are essential for CRC development and growth. Therefore, studying lncRNAs may reveal potential predictors of chemotherapy response and prognosis in CRC. LINC01764 was analyzed using datasets from Fudan University Shanghai Cancer Center's advanced CRC patients' RNA-seq and The Cancer Genome Atlas datasets. Gene set enrichment analysis was employed to detect related pathways. Cotransfection experiments, RNA pulldown assays, RNA-binding protein immunoprecipitation, protein synthesis activity, and dual-luciferase reporter assays were performed to determine interactions among LINC01764, hnRNPK, and c-MYC. High LINC01764 expression correlates with metastasis, a poor response to FOLFOX/XELOX chemotherapy, and a poor prognosis in CRC. LINC01764 enhance glycolysis and glutamine metabolism to promote CRC cells proliferation, metastasis, and 5-fluorouracil (5-FU) resistance. LINC01764 specifically binds to hnRNPK, facilitating its interaction with c-MYC mRNA and promoting internal ribosome entry site (IRES)-dependent translation of c-MYC, thereby exerting oncogenic effects. LINC01764 induced 5-FU chemoresistance by upregulating the c-MYC, glucose, and glutamine metabolism pathways, which downregulated UPP1, crucial for activating 5-FU. Conclusively, LINC01764 promotes CRC progression and 5-FU resistance through hnRNPK-mediated-c-MYC IRES-dependent translational regulation, which suggests its potential as a predictor of CRC chemotherapy response and prognosis.

Keywords:  5‐FU resistance; CRC; lncRNA; metastasis; proliferation

DOI:  https://doi.org/10.1002/mco2.70003
Free Radic Res. 2024 Nov 14. 1-14

NRF2 signaling and amino acid metabolism in cancer.

Suji Ham, Bo-Hyun Choi, Mi-Kyoung Kwak.

  Alterations in amino acid metabolism have emerged as a critical component in cancer biology, influencing various aspects of tumor initiation, progression, and metastasis. This review explores how amino acids, beyond their role as protein building blocks, are essential for redox balance, cell proliferation, metastasis, signaling/epigenetic regulation, and tumor microenvironment modulation in cancer. We particularly focus on the intricate relationship between amino acid metabolism and nuclear factor erythroid 2-related factor 2 (NRF2) signaling, a master regulator of oxidative stress response that frequently hyperactivated in cancer. Increasing evidence indicates that NRF2 is a key player in amino acid metabolism, orchestrating metabolism of cysteine, glutamine, and serine/glycine to promote cancer cell survival and growth. This comprehensive analysis provides insights into potential therapeutic strategies targeting the NRF2-amino acid metabolism axis, offering new avenues for cancer treatment that address multiple aspects of tumor biology.

Keywords:  NRF2; amino acid metabolism; cancer; cysteine; serine

DOI:  https://doi.org/10.1080/10715762.2024.2423690
Sci Rep. 2024 Nov 15. 14(1): 28193

Contribution of glucose and glutamine to hypoxia-induced lipid synthesis decreases, while contribution of acetate increases, during 3T3-L1 differentiation.

Lucie Ryskova, Katerina Pospisilova, Jiri Vavra, Tomas Wolf, Ales Dvorak, Libor Vitek, Jan Polak.

The molecular mechanisms linking obstructive sleep apnea syndrome (OSA) to obesity and the development of metabolic diseases are still poorly understood. The role of hypoxia (a characteristic feature of OSA) in excessive fat accumulation has been proposed. The present study investigated the possible effects of hypoxia (4% oxygen) on de novo lipogenesis by tracking the major carbon sources in differentiating 3T3-L1 adipocytes. Gas-permeable cultuware was employed to cultivate 3T3-L1 adipocytes in hypoxia (4%) for 7 or 14 days of differentiation. We investigated the contribution of glutamine, glucose or acetate using 13C or 14C labelled carbons to the newly synthesized lipid pool, changes in intracellular lipid content after inhibiting citrate- or acetate-dependent pathways and gene expression of involved key enzymes. The results demonstrate that, in differentiating adipocytes, hypoxia decreased the synthesis of lipids from glucose (44.1 ± 8.8 to 27.5 ± 3.0 pmol/mg of protein, p < 0.01) and partially decreased the contribution of glutamine metabolized through the reverse tricarboxylic acid cycle (4.6% ± 0.2-4.2% ± 0.1%, p < 0.01). Conversely, the contribution of acetate, a citrate- and mitochondria-independent source of carbons, increased upon hypoxia (356.5 ± 71.4 to 649.8 ± 117.5 pmol/mg of protein, p < 0.01). Further, inhibiting the citrate- or acetate-dependent pathways decreased the intracellular lipid content by 58% and 73%, respectively (p < 0.01) showing the importance of de novo lipogenesis in hypoxia-exposed adipocytes. Altogether, hypoxia modified the utilization of carbon sources, leading to alterations in de novo lipogenesis in differentiating adipocytes and increased intracellular lipid content.

DOI: https://doi.org/10.1038/s41598-024-79458-0
Biotechnol J. 2024 Nov;19(11): e202400072

Genome-Scale Modeling of CHO Cells Unravel the Critical Role of Asparagine in Cell Culture Feed Media.

Kuin Tian Pang, Yi Fan Hong, Fumi Shozui, Shunpei Furomitsu, Matthew Myint, Ying Swan Ho, Yaron R Silberberg, Ian Walsh, Meiyappan Lakshmanan.

  Amino acids, including asparagine, aspartate, glutamine, and glutamate, play important roles in purine and pyrimidine biosynthesis as well as serve as anaplerotic sources fueling the tricarboxylic acid (TCA) cycle for mitochondrial energy generation. Despite extensive studies on glutamine and glutamate in CHO cell cultures, the roles of asparagine and aspartate, especially in feed media, remain underexplored. In this study, we utilized a CHO genome scale model to first deeply characterize the intracellular metabolic states of CHO cells cultured in different combinations of basal and feed media to understand the traits of asparagine/aspartate-dependent and glutamate-dependent feeds. Subsequently, we identified the critical role of asparagine and aspartate in the feed media as anaplerotic sources and conducted in silico simulations to ascertain their optimal ratios to improve cell culture performance. Finally, based on the model simulations, we reformulated the feed media by tailoring the concentrations of asparagine and aspartate. Our experimental data reveal a CHO cell preference for asparagine compared with aspartate, and thus maintaining an optimal ratio of these amino acids is a key factor for achieving optimal CHO cell culture performance in biopharmaceutical production.

Keywords:  Chinese hamster ovary (CHO) cells; enzyme capacity constrained flux balance analysis (ecFBA); genome‐scale model (GEM); mammalian systems biotechnology

DOI:  https://doi.org/10.1002/biot.202400072
Int J Mol Sci. 2024 Oct 28. pii: 11572. [Epub ahead of print]25(21):

Hydroxyacid Oxidase 1, a Glutamine Metabolism-Associated Protein, Predicts Poor Patient Outcome in Luminal Breast Cancer.

Busra Erkan, Skye MacIntyre, Charlotte Brown, Ali Fakroun, Ayat G Lashen, Nigel P Mongan, Ian O Ellis, Emad A Rakha, Andrew R Green.

  Breast cancer (BC), which remains the most prevalent malignancy among women, is characterised by significant heterogeneity across its molecular subtypes. Oestrogen receptor-positive (ER+) (luminal) BC represents approximately 75% of cases, and despite advancements in treatment there remains around a 40% recurrence rate. Cellular uptake of glutamine is conducted by solute carriers (SLCs), which are significantly associated with outcome in luminal BC. In this study, differential gene expression analysis was carried out using The Cancer Genome Atlas BC dataset. This identified hydroxyacid oxidase 1 (HAO1) as significantly overexpressed in luminal BC with a high expression of SLCs. Extended analysis in the METABRIC (n = 1980) and Breast Cancer Gene-Expression Miner (n = 4421) transcriptomic databases and the Nottingham (n = 952) BC tissue cohort showed a varied survival outcome for HAO1 expression at the genomic, transcriptomic, and proteomic levels. HAO1 copy number (CN) gain (p = 0.002) and high HAO1 protein expression (p = 0.019) were associated with poor prognosis in luminal BC, whereas high HAO1 mRNA expression correlated with better survival outcomes (p = 0.023) suggesting a complex regulatory mechanism affecting HAO1 at different biological levels. Importantly, in luminal BC patients treated with endocrine therapy, high protein expression of HAO1 predicted shorter distant-metastasis free survival (p = 0.042). The knockdown of SLC1A5 and SLC7A5 significantly reduced HAO1 expression in MCF-7 and ZR-751 BC cell lines. Protein analysis confirmed significant associations between HAO1 and SLC7A5 and SLC1A5, emphasising a potential role for the enzyme in glutamine metabolism and its potential as a therapeutic target. This study underscores the prognostic significance of HAO1 in luminal BC and its relationship with patient outcomes.

Keywords:  hydroxyacid oxidase 1; luminal breast cancer; oestrogen receptor; prognostic significance; solute carriers

DOI:  https://doi.org/10.3390/ijms252111572
Int J Biol Markers. 2024 Nov 08. 3936155241296164

Impact of metabolism-related markers on outcomes in ovarian cancer patients: Findings of the MITO16A/MaNGO-OV2 trial.

Stefano Indraccolo, Simona Signoriello, Ilaria Piga, Giovanni Esposito, Federica Ferrarini, Andrea Boscolo Bragadin, Vanda Salutari, Carmela Pisano, Daniela Califano, Eliana Bignotti, Germana Tognon, Vittorio Simeon, Grazia Artioli, Annamaria Ferrero, Saverio Cinieri, Alessandra Bologna, Paolo Chiodini, Giosuè Scognamiglio, Carolina Bottoni, Anna Spina, Daniela Russo, Laura Arenare, Francesco Perrone, Sandro Pignata.

   INTRODUCTION: In ovarian cancer, expression of metabolism-related markers has been investigated in several studies focusing on individual markers; however, a parallel quantitative evaluation of markers mapping to distinct metabolic processes and their prognostic value in large patient cohorts is still lacking.
METHODS: Here, by using immunohistochemistry followed by digital pathology, we investigated the expression of several markers related to glycolysis including monocarboxylate transporter 1 and 4 (MCT1, MCT4), glutamine metabolism (glutaminase, GLS) and hypoxia/acidosis (carbonic anhydrase 9, CA IX) in tissue microarrays of > 300 patients recruited in the MITO16A clinical trial, which involved treatment of ovarian cancer patients with carboplatin/taxol plus bevacizumab.
RESULTS: Regarding the prognostic impact of these markers, results indicate that GLS expression correlated with progression-free survival, but this effect disappeared when data were corrected for multiple testing. All other markers showed no correlation with clinical outcome.
CONCLUSION: These results indicate marked heterogeneity of expression of metabolism-associated markers in ovarian cancer; however, there was a lack of association with clinical benefit after chemotherapy/anti-vascular endothelial growth factor treatment. Notwithstanding the lack of prognostic value, knowledge of the pattern of expression of these biomarkers in tumors can be useful for patient stratification purposes when new drugs targeting these metabolic pathways will be tested.

Keywords:  Ovarian cancer; angiogenesis; bevacizumab; glycolysis; metabolism

DOI:  https://doi.org/10.1177/03936155241296164
Int J Biochem Cell Biol. 2024 Nov 13. pii: S1357-2725(24)00187-0. [Epub ahead of print] 106694

Prolonged glutamine starvation reactivates mTOR to inhibit autophagy and initiate autophagic lysosome reformation to maintain cell viability.

Amruta Singh, Kewal Kumar Mahapatra, Prakash Priyadarshi Praharaj, Srimanta Patra, Soumya Ranjan Mishra, Sankargouda Patil, Sujit Kumar Bhutia.

  Autophagy, a cellular recycling mechanism, utilizes lysosomes for cellular degradation. Prolonged autophagy reduces the pool of functional lysosomes in the cell. However, lysosomal homeostasis is maintained through the regeneration of functional lysosomes during the terminal stage of autophagy, i.e. Autophagic lysosome reformation (ALR). Through confocal microscopy during glutamine starvation, we unravel the regeneration of tubules from autolysosomes by undertaking significant membrane remodeling, which majorly depends on mTOR reactivation, RAB7 dissociation, phosphatidyl inositol 3 phosphate (PI3P) dependent dynamin 2 and clathrin recruitment. In glutamine-starved cells, we found mTOR is the central modulator in regulating ALR initiation, and its pharmacological inhibition with rapamycin leads to a decrease in lysosomal tubulation. Moreover, RAB7 and Clathrin are essential for tubule elongation and it showed that siRNA targeting RAB7 and Clathrin restricts tubule initiation under glutamine starvation. In this setting, we examined the physiological relevance of ALR during prolonged glutamine deprivation and found that genetic and pharmacological inhibition of critical proteins involved in ALR promotes cell death in oral cancer cells, establishing ALR is essential for maintaining cell survival during stress.

Keywords:  Autolysosome; Autophagic lysosome reformation; Autophagy; Mammalian target of Rapamycin; Proto-lysosome

DOI:  https://doi.org/10.1016/j.biocel.2024.106694
J Transl Med. 2024 Nov 07. 22(1): 1004

SLC38A5 suppresses ferroptosis through glutamine-mediated activation of the PI3K/AKT/mTOR signaling in osteosarcoma.

Xinghan Huang, Kezhou Xia, Zhun Wei, Wenda Liu, Zicheng Wei, Weichun Guo.

   BACKGROUND: Solute carrier family 38 member 5 (SLC38A5) is an amino acid transporter that plays a significant role in various cellular biological processes and may be involved in regulating the progression of tumors However, its function and underlying mechanism in osteosarcoma remain unexplored.
METHODS: Utilizing various database analyses and experiments, we have explored the dysregulation of SLC38A5 in osteosarcoma and its prognostic value. A series of in vitro functional experiments, including CCK-8, colony formation, wound healing, and transwell invasion assays, were conducted to evaluate the effects of SLC38A5 on the proliferation, migration, and invasion of osteosarcoma cells. Downstream pathways of SLC38A5 were explored through methods such as western blot and metabolic assays, followed by a series of validations. Finally, we constructed a subcutaneous xenograft tumor model in nude mice to explore SLC38A5 function in vivo.
RESULTS: SLC38A5 is upregulated in osteosarcoma and is associated with poor prognosis in patients. Upregulation of SLC38A5 promotes proliferation, migration, and invasion of osteosarcoma cells, while the PI3K inhibitor BKM120 can counteract these effects. Additionally, silencing of SLC38A5 inhibits tumor growth in vivo. Mechanistically, SLC38A5 mediates the activation of the PI3K/AKT/mTOR signaling pathway by transporting glutamine, which subsequently enhances the SREBP1/SCD-1 signaling pathway, thereby suppressing ferroptosis in osteosarcoma cells.
CONCLUSION: SLC38A5 promotes osteosarcoma cell proliferation, migration, and invasion via the glutamine-mediated PI3K/AKT/mTOR signaling pathway and inhibits ferroptosis. Targeting SLC38A5 and the PI3K/AKT signaling axis may provide a meaningful therapeutic strategy for the future treatment of osteosarcoma.

Keywords:  Osteosarcoma; PI3K/AKT/mTOR pathway; SLC38A5; ferroptosis; glutamine

DOI:  https://doi.org/10.1186/s12967-024-05803-6
Cancers (Basel). 2024 Oct 28. pii: 3629. [Epub ahead of print]16(21):

Targeting Cancer Metabolism as a New Strategy to Enhance Treatment Efficacy and Overcome Resistance.

Paola Tucci.

The intricate relationship between metabolism and cancer has been a subject of growing interest in recent years, as metabolic reprogramming is recognized as one of the hallmarks of cancer [...].

DOI: https://doi.org/10.3390/cancers16213629
J Nanobiotechnology. 2024 Nov 13. 22(1): 703

Targeting glutamine synthetase with AS1411-modified exosome-liposome hybrid nanoparticles for inhibition of choroidal neovascularization.

Miaomiao Zhang, Xinyue Lu, Lifu Luo, Jinqiu Dou, Jingbo Zhang, Ge Li, Li Zhao, Fengying Sun.

  Choroidal neovascularization (CNV) is a leading cause of visual impairment in wet age-related macular degeneration (wAMD). Recent investigations have validated the potential of reducing glutamine synthetase (GS) to inhibit neovascularization formation, offering prospects for treating various neovascularization-related diseases. In this study, we devised a CRISPR/Cas9 delivery system employing the nucleic acid aptamer AS1411 as a targeting moiety and exosome-liposome hybrid nanoparticles as carriers (CAELN). Exploiting the binding affinity between AS1411 and nucleolin on endothelial cell surfaces, the delivery system was engineered to specifically target the glutamine synthetase gene (GLUL), thereby attenuating GS levels and continuously suppressing CNV. CAELN exhibited spherical and uniform dispersion. In vitro cellular investigations demonstrated gene editing efficiencies of CAELN ranging from 42.05 to 55.02% and its capacity to inhibit neovascularization in HUVEC cells. Moreover, in vivo pharmacodynamic studies conducted in CNV rabbits revealed efficacy of CAELN in restoring the thickness of intra- and extranuclear tissues. The findings suggest that GS is a novel target for the inhibition of pathological CNV, while the development of AS1411-modified exosome-liposome hybrid nanoparticles represents a novel delivery method for the treatment of neovascular-related diseases.

Keywords:  Age-related macular degeneration; CRISPR/Cas9; Choroidal neovascularization; Exosome; Glutamine synthetase; Liposome; Nucleic acid aptamer; Vascular endothelial growth factor

DOI:  https://doi.org/10.1186/s12951-024-02943-1
Int J Mol Sci. 2024 Oct 22. pii: 11339. [Epub ahead of print]25(21):

Glutathione and Selenium Supplementation Attenuates Liver Injury in Diethylnitrosamine-Induced Hepatocarcinogenic Mice by Enhancing Glutathione-Related Antioxidant Capacities.

Yung-Fang Hsiao, Shih-Chien Huang, Shao-Bin Cheng, Cheng-Chin Hsu, Yi-Chia Huang.

  Excess oxidative stress and inadequate antioxidant capacities are critical features in the development of hepatocellular carcinoma. This study aimed to determine whether supplementation with glutathione (GSH) and/or selenium (Se), as antioxidants, attenuates diethylnitrosamine (DEN)-induced hepatocarcinogenesis in mice. C57BL/6J male mice were randomly assigned to control, DEN, DEN + GSH, DEN + Se, and DEN + GSH + Se groups for 20 weeks. Daily supplementation with GSH and/or Se commenced in the first experimental week and continued throughout the study. DEN was administered in weeks 2-9 and 16-19 of the experimental period. DEN administration induced significant pathological alterations of hepatic foci, evidenced by elevated levels of liver function, accompanied by high malondialdehyde (MDA) levels; low GSH levels; and glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione S-transferase (GST) activities. Supplementation with GSH and Se significantly ameliorated liver pathological changes, reducing liver function and MDA levels while increasing GSH levels and GPx, GR, and GST activities. Notably, combined supplementation with GSH and Se more effectively increased the GSH/glutathione disulfide ratio and GPx activity than individual supplementation. Supplementation with GSH and Se attenuated liver injury in DEN-induced hepatocarcinogenic mice by enhancing GSH and its related antioxidant capacities, thereby mitigating oxidative damage.

Keywords:  glutathione; glutathione peroxidase; hepatocarcinogenesis; oxidative stress; selenium

DOI:  https://doi.org/10.3390/ijms252111339
Cell Death Dis. 2024 Nov 12. 15(11): 820

SNF2L maintains glutathione homeostasis by initiating SLC7A11 transcription through chromatin remodeling.

Jiaguan Zhang, Zeshou Gao, Yi Yang, Zhenhao Li, Binjie Wu, Chunxin Fan, Yuyan Zheng, Ruohan Yang, Fangrong Zhang, Xiaohuang Lin, Daoshan Zheng.

SNF2L encodes an ISWI chromatin remodeling factor that promotes gene transcription and is consistently elevated in cancers. Previous studies have shown that inhibiting SNF2L expression in cancer cells leads to significant growth suppression, DNA damage, and cell death. However, the underlying mechanisms remain poorly understood. In this study, we demonstrated that cancer cells lacking SNF2L show significantly decreased glutathione (GSH) levels, leading to elevated reactive oxygen species (ROS) and increased oxidative stress. SNF2L deficiency also heightened the sensitivity of cancer cells to APR-246, a drug that depletes GSH and induces oxidative stress, consequently decreasing cell viability and increasing ROS levels, regardless of p53 status. Mechanistically, we found that NRF2 recruits SNF2L to the SLC7A11 promoter, leading to increased chromatin accessibility and facilitating SLC7A11 transcription. This results in decreased cystine uptake and impaired GSH biosynthesis. These findings suggest that targeting the SNF2L/SLC7A11 axis could enhance the effectiveness of APR-246 by depleting GSH and increasing ROS level in cancer cells, highlighting SNF2L as a promising therapeutic target.

DOI: https://doi.org/10.1038/s41419-024-07221-4
Front Immunol. 2024 ;15 1467151

LncRNAs in tumor metabolic reprogramming and tumor microenvironment remodeling.

Jianhang Jiao, Yangzhi Zhao, Qimei Li, Shunzi Jin, Zhongshan Liu.

  The tumor microenvironment (TME) is a complex and dynamic ecosystem composed of tumor cells, immune cells, supporting cells, and the extracellular matrix. Typically, the TME is characterized by an immunosuppressive state. To meet the demands of rapid proliferation, cancer cells undergo metabolic reprogramming, which enhances their biosynthesis and bioenergy supply. Immune cells require similar nutrients for activation and proliferation, leading to competition and immunosuppression within the TME. Additionally, tumor metabolites inhibit immune cell activation and function. Consequently, an immunosuppressed and immune-tolerant TME promotes cancer cell proliferation and metastasis. Long non-coding RNAs (lncRNAs), a category of non-coding RNA longer than 200 nucleotides, regulate tumor metabolic reprogramming by interacting with key enzymes, transporters, and related signaling pathways involved in tumor metabolism. Furthermore, lncRNAs can interact with both cellular and non-cellular components in the TME, thereby facilitating tumor growth, metastasis, drug resistance, and inducing immunosuppression. Recent studies have demonstrated that lncRNAs play a crucial role in reshaping the TME by regulating tumor metabolic reprogramming. In this discussion, we explore the potential mechanisms through which lncRNAs regulate tumor metabolic reprogramming to remodel the TME. Additionally, we examine the prospects of lncRNAs as targets for anti-tumor therapy and as biomarkers for tumor prognosis.

Keywords:  lncRNAs; metabolic reprogramming; tumor immunity; tumor immunotherapy; tumor microenvironment remodeling

DOI:  https://doi.org/10.3389/fimmu.2024.1467151
Int J Mol Sci. 2024 Oct 28. pii: 11561. [Epub ahead of print]25(21):

The Glutamine Synthetases Are Required for Sensory Hair Cell Formation and Auditory Function in Zebrafish.

Yuanrong Zhao, Ziyang Wang, Mengting Xu, Fuping Qian, Guanyun Wei, Dong Liu.

  The development of sensory hair cells (HCs) is closely linked to hearing loss. There are still many unidentified genes that may play a crucial role in HC development and function. Glutamine synthetase, Glul, is expressed in sensory hair cells and auditory organs. However, the role of the Glul gene family in the auditory system remains largely unexplored. This study aims to investigate the function of the Glul gene family in the auditory system. The expression patterns of the glul gene family were examined via in situ hybridization in zebrafish embryos. It was revealed that the expression of glula occurred in the otic vesicle, while glulb was expressed in the neuromast. In contrast, glulc did not exhibit any discernible signal. glula loss of function caused abnormal otolith formation and reduced hair cell number in otic vesicles, while glulb knockdown caused a decrease in HC number in both neuromasts and otic vesicles and impaired auditory function. Furthermore, we found that the knockdown of glulb induces apoptosis of hair cells. Transcriptomic analysis of zebrafish with glula and glulb knockdown revealed significant alterations in the expression of many genes associated with auditory organs. The current study sheds light on the requirement of glula and glulb in zebrafish hair cell formation and auditory function.

Keywords:  apoptosis; glutamine synthetases; hair cells; hearing; zebrafish

DOI:  https://doi.org/10.3390/ijms252111561
J Am Soc Mass Spectrom. 2024 Nov 12.

Measuring 15N and 13C Enrichment Levels in Sparsely Labeled Proteins Using High-Resolution and Tandem Mass Spectrometry.

Elijah T Roberts, Jonathan Choi, Jeremy Risher, Paul G Kremer, Adam W Barb, I Jonathan Amster.

Isotope labeling of both 15N and 13C in selected amino acids in a protein, known as sparse labeling, is an alternative to uniform labeling and is particularly useful for proteins that must be expressed using mammalian cells, including glycoproteins. High levels of enrichment in the selected amino acids enable multidimensional heteronuclear NMR measurements of glycoprotein three-dimensional structure. Mass spectrometry provides a means to quantify the degree of enrichment. Mass spectrometric measurements of tryptic peptides of a selectively labeled glycoprotein expressed in HEK293 cells revealed complicated isotope patterns which consisted of many overlapping isotope patterns from intermediately labeled peptides, which complicates the determination of the label incorporation. Two challenges are uncovered by these measurements. Metabolic scrambling of amino groups can reduce the 15N content of enriched amino acids or increase the 15N in nontarget amino acids. Also, undefined, unlabeled medium components may dilute the enrichment level of labeled amino acids. The impact of this unexpected metabolic scrambling was overcome by simulating isotope patterns for all isotope-labeled peptide states and generating linear combinations to fit to the data. This method has been used to determine the percent incorporation of 15N and 13C labels and has identified several metabolic scrambling effects that were previously undetected in NMR experiments. Ultrahigh mass resolution is also utilized to obtain isotopic fine structure, from which enrichment levels of 15N and 13C can be assigned unequivocally. Finally, tandem mass spectrometry can be used to confirm the location of heavy isotope labels in the peptides.

DOI: https://doi.org/10.1021/jasms.4c00237
Spectrochim Acta A Mol Biomol Spectrosc. 2024 Nov 10. pii: S1386-1425(24)01561-0. [Epub ahead of print]327 125395

Dual-locked NIR fluorescent probe for detection of GSH and lipid droplets and its bioimaging application in cancer model.

Jingcan Qin, Fei Kong, Dachuan Zhang, Xiao Han Yuan, Yun Bian, Chengwei Shao.

  Fluorescence probes with outstanding merits have wide applications in tumor diagnosis. However, most of these probes can only detect single tumor biomarker, potentially generating "false positive" signals within intricate biological systems. In contrast, the dual-locked fluorescent probes triggered by two response factors can effectively address the aforementioned limitations. In this work, we fabricated a novel coumarin-based NIR fluorescent probe (CP-GSH), demonstrating dual-responsiveness to high glutathione (GSH) concentrations and high viscosity. Specifically, the probe showed strong fluorescence enhancement at 675 nm ∼ 725 nm in the simultaneous presence of GSH and high viscosity, whereas the presence of either GSH or high viscosity alone could not induce a noticeable change in fluorescence intensity of CP-GSH. More importantly, the bioimaging experiments further validated CP-GSH triggered by endogenous GSH possessed excellent targeting capability towards lipid droplets (LDs), which could be utilized to effective discriminate between cancer cells and normal cells. This work proposes a promising strategy for the design of dual-locked probe for tumor imaging.

Keywords:  Dual-lock NIR fluorescent probe; GSH; Tumor imaging; Viscosity/ lipid droplets

DOI:  https://doi.org/10.1016/j.saa.2024.125395