bims-glucam 2024-11-03 papers

bims-glucam

Biomed News

on Glutamine cancer metabolism

Issue of 2024‒11‒03
nineteen papers selected by
Sreeparna Banerjee, Middle East Technical University

Gefitinib Reverses PD-L1-Mediated Immunosuppression Induced by long-term Glutamine blockade in Bladder Cancer.
Glucose and glutamine drive hepatitis E virus replication.
Inhibition of Glutamate-to-Glutathione Flux Promotes Tumor Antigen Presentation in Colorectal Cancer Cells.
Metabolic Reprogramming in Cancer: Implications for Immunosuppressive Microenvironment.
Noncanonical TCA cycle fosters canonical TCA cycle and mitochondrial integrity in acute myeloid leukemia.
Metabolic reprogramming in KRAS-mutant cancers: Proven targetable vulnerabilities and potential therapeutic strategies.
The Research Progress of Metformin Regulation of Metabolic Reprogramming in Malignant Tumors.
How Does Cancer Occur? How Should It Be Treated? Treatment from the Perspective of Alkalization Therapy Based on Science-Based Medicine.
Amino acid is a major carbon source for hepatic lipogenesis.
PRODH Regulates Tamoxifen Resistance through Ferroptosis in Breast Cancer Cells.
Targeting metabolic pathway enhance CAR-T potency for solid tumor.
Insights into Metabolic Reprogramming in Tumor Evolution and Therapy.
Preparation of D-NCCDs and its application in fluorescent/colorimetric dual-mode discrimination of glutamine enantiomers.
Role of Glutamine Synthetase on Vascular Permeability in Gliomas.
Glutamine and serum starvation alters the ATP production, oxidative stress, and abundance of mitochondrial RNAs in extracellular vesicles produced by cancer cells.
Copper drives remodeling of metabolic state and progression of clear cell renal cell carcinoma.
A Hybrid Alloying Nanozyme-Glutathione Inhibitor Co-Delivery System Initiates a Dual-Disruption on Cancer Redox Homeostasis.
Glutamate Transport Proteins and Metabolic Enzymes are Poor Prognostic Factors in Invasive Lobular Carcinoma.
Application of CRISPR/Cas9 Genome Editing to Improve Recombinant Protein Production in CHO Cells.

Cancer Immunol Res. 2024 Oct 29.

Gefitinib Reverses PD-L1-Mediated Immunosuppression Induced by long-term Glutamine blockade in Bladder Cancer.

Guofeng Ma, Huiqing Jia, Zhiqiang Li, Xiangyan Zhang, Liping Wang, Zhilei Zhang, Yujing Xiao, Zhijuan Liang, Dan Li, Yuanbin Chen, Xintao Tian, Yonghua Wang, Ye Liang, Haitao Niu.

Glutamine is a major energy source for tumor cells and blocking glutamine metabolism is being investigated as a promising strategy for cancer therapy. However, the antitumor effect of glutamine blockade in bladder cancer remains unclear, necessitating further investigation. Here, we demonstrated that glutamine metabolism was involved in the malignant progression of bladder cancer. Treatment with the glutamine antagonist 6-Diazo-5-oxo-L-norleucine (DON) inhibited the growth of bladder cancer cells in vitro in several ways. In addition, we observed inhibition of tumor growth in bladder cancer-bearing mice using JHU083, a prodrug that was designed to prevent DON-induced toxicity. However, the antitumor immune effect of T cells changed from activation to inhibition as the administrated time extended. We found that both in vitro treatment with DON and in vivo prolonged administration of JHU083 led to the upregulation of PD-L1 in bladder cancer cells. Mechanistically, glutamine blockade up-regulated PD-L1 expression in bladder cancer cells by accumulating ROS, subsequently activating the EGFR/ERK/C-Jun signaling pathway. Combination treatment of JHU083 and gefitinib reversed the up-regulation of PD-L1 in bladder cancer cells induced by prolonged glutamine blockade, resulting in the alleviation of T-cell immunosuppression and a significant improvement in therapeutic outcome. These preclinical findings show promise for glutamine metabolism targeting as a viable therapeutic strategy for bladder cancer, with the potential for further enhancement through combined treatment with gefitinib.

DOI: https://doi.org/10.1158/2326-6066.CIR-24-0039
Arch Virol. 2024 Oct 30. 169(11): 233

Glucose and glutamine drive hepatitis E virus replication.

Shaheen Khan, Suruchi Aggarwal, Pooja Bhatia, Amit Kumar Yadav, Yashwant Kumar, Naga Suresh Veerapu.

  Viruses have undergone evolutionary adaptations to tune their utilization of carbon sources, enabling them to extract specific cellular substrates necessary for their replication. The lack of a reliable cell culture system and a small-animal model has hampered our understanding of the molecular mechanism of replication of hepatitis E virus (HEV) genotype 1. Our recent identification of a replicative ensemble of mutant HEV RNA libraries has allowed us to study the metabolic prerequisites for HEV replication. Initial assessments revealed increased glucose and glutamine utilization during HEV replication. Inhibition of glycolysis and glycolysis + glutaminolysis reduced the levels of HEV replication to similar levels. An integrated analysis of protein-metabolite pathways suggests that HEV replication markedly alters glycolysis, the TCA cycle, and glutamine-associated metabolic pathways. Cells supporting HEV replication showed a requirement for fructose-6-phosphate and glutamine utilization through the hexosamine biosynthetic pathway (HBP), stimulating HSP70 expression to facilitate virus replication. Observations of mannose utilization and glutamine dependence suggest a crucial role of the HBP in supporting HEV replication. Inhibition of glycolysis and HSP70 activity or knockdown of glutamine fructose-6-phosphate amidotransferase expression led to a substantial reduction in HEV RNA and ORF2 expression accompanied by a significant decrease in HSP70 levels. This study demonstrates that glucose and glutamine play critical roles in facilitating HEV replication.

Keywords:  Glutaminolysis; Glycolysis; HSP70; HSP90; Hepatitis E virus; Hexosamine biosynthetic pathway

DOI:  https://doi.org/10.1007/s00705-024-06160-x
Adv Sci (Weinh). 2024 Oct 31. e2310308

Inhibition of Glutamate-to-Glutathione Flux Promotes Tumor Antigen Presentation in Colorectal Cancer Cells.

Tao Yu, Kevin Van der Jeught, Haiqi Zhu, Zhuolong Zhou, Samantha Sharma, Sheng Liu, Haniyeh Eyvani, Ka Man So, Naresh Singh, Jia Wang, George E Sandusky, Yunlong Liu, Mateusz Opyrchal, Sha Cao, Jun Wan, Chi Zhang, Xinna Zhang.

  Colorectal cancer (CRC) cells display remarkable adaptability, orchestrating metabolic changes that confer growth advantages, pro-tumor microenvironment, and therapeutic resistance. One such metabolic change occurs in glutamine metabolism. Colorectal tumors with high glutaminase (GLS) expression exhibited reduced T cell infiltration and cytotoxicity, leading to poor clinical outcomes. However, depletion of GLS in CRC cells has minimal effect on tumor growth in immunocompromised mice. By contrast, remarkable inhibition of tumor growth is observed in immunocompetent mice when GLS is knocked down. It is found that GLS knockdown in CRC cells enhanced the cytotoxicity of tumor-specific T cells. Furthermore, the single-cell flux estimation analysis (scFEA) of glutamine metabolism revealed that glutamate-to-glutathione (Glu-GSH) flux, downstream of GLS, rather than Glu-to-2-oxoglutarate flux plays a key role in regulating the immune response of CRC cells in the tumor. Mechanistically, inhibition of the Glu-GSH flux activated reactive oxygen species (ROS)-related signaling pathways in tumor cells, thereby increasing the tumor immunogenicity by promoting the activity of the immunoproteasome. The combinatorial therapy of Glu-GSH flux inhibitor and anti-PD-1 antibody exhibited a superior tumor growth inhibitory effect compared to either monotherapy. Taken together, the study provides the first evidence pointing to Glu-GSH flux as a potential therapeutic target for CRC immunotherapy.

Keywords:  MHC‐I antigen presentation; colorectal cancer; glutamine metabolism; immune checkpoint blockade; immunoproteasome; single‐cell flux estimation analysis

DOI:  https://doi.org/10.1002/advs.202310308
Immunology. 2024 Oct 27.

Metabolic Reprogramming in Cancer: Implications for Immunosuppressive Microenvironment.

Durre Aden, Niti Sureka, Samreen Zaheer, Jai Kumar Chaurasia, Sufian Zaheer.

  Cancer is a complex and heterogeneous disease characterised by uncontrolled cell growth and proliferation. One hallmark of cancer cells is their ability to undergo metabolic reprogramming, which allows them to sustain their rapid growth and survival. This metabolic reprogramming creates an immunosuppressive microenvironment that facilitates tumour progression and evasion of the immune system. In this article, we review the mechanisms underlying metabolic reprogramming in cancer cells and discuss how these metabolic alterations contribute to the establishment of an immunosuppressive microenvironment. We also explore potential therapeutic strategies targeting metabolic vulnerabilities in cancer cells to enhance immune-mediated anti-tumour responses. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02044861, NCT03163667, NCT04265534, NCT02071927, NCT02903914, NCT03314935, NCT03361228, NCT03048500, NCT03311308, NCT03800602, NCT04414540, NCT02771626, NCT03994744, NCT03229278, NCT04899921.

Keywords:  cancer; immunosuppressive microenvironment; metabolic reprogramming

DOI:  https://doi.org/10.1111/imm.13871
Cancer Sci. 2024 Oct 31.

Noncanonical TCA cycle fosters canonical TCA cycle and mitochondrial integrity in acute myeloid leukemia.

Atsushi Watanabe, Chartsiam Tipgomut, Haruhito Totani, Kentaro Yoshimura, Tomohiko Iwano, Hamed Bashiri, Lee Hui Chua, Chong Yang, Toshio Suda.

  Cancer cells rely on mitochondrial oxidative phosphorylation (OXPHOS) and the noncanonical tricarboxylic acid (TCA) cycle. In this paper, we shed light on the vital role played by the noncanonical TCA cycle in a host-side concession to mitochondria, especially in highly energy-demanding malignant tumor cells. Inhibition of ATP-citrate lyase (ACLY), a key enzyme in the noncanonical TCA cycle, induced apoptosis by increasing reactive oxygen species levels and DNA damage while reducing mitochondrial membrane potential. The mitochondrial membrane citrate transporter inhibitor, CTPI2, synergistically enhanced these effects. ACLY inhibition reduced cytosolic citrate levels and CTPI2 lowered ACLY activity, suggesting that the noncanonical TCA cycle is sustained by a positive feedback mechanism. These inhibitions impaired ATP production, particularly through OXPHOS. Metabolomic analysis of mitochondrial and cytosolic fractions revealed reduced levels of glutathione pathway-related and TCA cycle-related metabolite, except fumarate, in mitochondria following noncanonical TCA cycle inhibition. Despite the efficient energy supply to the cell by mitochondria, this symbiosis poses challenges related to reactive oxygen species and mitochondrial maintenance. In conclusion, the noncanonical TCA cycle is indispensable for the canonical TCA cycle and mitochondrial integrity, contributing to mitochondrial domestication.

Keywords:  ATP‐citrate lyase; antimetabolites; apoptosis; cancer metabolism; cell lines; hematopoietic organ; mitochondria; noncanonical TCA cycle; others; reactive oxygen species

DOI:  https://doi.org/10.1111/cas.16347
Drug Discov Today. 2024 Oct 29. pii: S1359-6446(24)00345-3. [Epub ahead of print] 104220

Metabolic reprogramming in KRAS-mutant cancers: Proven targetable vulnerabilities and potential therapeutic strategies.

Ruilin Wu, Hong Zhu, Qiaojun He, Tao Yuan, Bo Yang.

  Kras (Ki-ras2 Kirsten rat sarcoma viral oncogene homolog), one of the most frequently mutated oncogenes in the human genome, is considered 'untargetable'. Although specific KRASG12C inhibitors have been developed, their overall impact is limited, highlighting the need for further research on targeting KRAS-mutant cancers. Metabolic abnormalities are key hallmarks of cancer, with KRAS-driven tumors exhibiting traits like glycolysis upregulation, glutamine addiction, lipid droplet accumulation, highly active macropinocytosis, and metabolic reprogramming-associated tumor microenvironment remodeling. Targeting these unique metabolic characteristics offers a promising strategy for new cancer treatments. This review summarizes recent advances in our understanding of the metabolic network in KRAS-mutated tumor cells, discusses potential targetable vulnerabilities, and outlines clinical developments in relevant therapies, while also addressing challenges to improve strategies against these aggressive cancers.

Keywords:  KRAS-mutant cancers; clinical practice; metabolic reprogramming; therapeutic strategies

DOI:  https://doi.org/10.1016/j.drudis.2024.104220
Pharm Res. 2024 Oct 25.

The Research Progress of Metformin Regulation of Metabolic Reprogramming in Malignant Tumors.

Qihai Sui, Huiqiang Yang, Zhengyang Hu, Xing Jin, Zhencong Chen, Wei Jiang, Fenghao Sun.

  BACKGROUND: Metabolism reprogramming is a crucial hallmark of malignant tumors. Tumor cells demonstrate enhanced metabolic efficiency, converting nutrient inputs into glucose, amino acids, and lipids essential for their malignant proliferation and progression. Metformin, a commonly prescribed medication for type 2 diabetes mellitus, has garnered attention for its potential anticancer effects beyond its established hypoglycemic benefits.METHODS: This review adopts a comprehensive approach to delineate the mechanisms underlying metabolite abnormalities within the primary metabolic processes of malignant tumors.
RESULTS: This review examines the abnormal activation of G protein-coupled receptors (GPCRs) in these metabolic pathways, encompassing aerobic glycolysis with increased lactate production in glucose metabolism, heightened lipid synthesis and cholesterol accumulation in lipid metabolism, and glutamine activation alongside abnormal protein post-translational modifications in amino acid and protein metabolism. Furthermore, the intricate metabolic pathways and molecular mechanisms through which metformin exerts its anticancer effects are synthesized and analyzed, particularly its impacts on AMP-activated protein kinase activation and the mTOR pathway. The analysis reveals a multifaceted understanding of how metformin can modulate tumor metabolism, targeting key nodes in metabolic reprogramming essential for tumor growth and progression. The review compiles evidence that supports metformin's potential as an adjuvant therapy for malignant tumors, highlighting its capacity to interfere with critical metabolic pathways.
CONCLUSION: In conclusion, this review offers a comprehensive overview of the plausible mechanisms mediating metformin's influence on tumor metabolism, fostering a deeper comprehension of its anticancer mechanisms. By expanding the clinical horizons of metformin and providing insight into metabolism-targeted tumor therapies, this review lays the groundwork for future research endeavors aimed at refining and advancing metabolic intervention strategies for cancer treatment.

Keywords:  Combination therapy; Malignant tumor; Metabolic reprogramming; Metformin; Tumor metabolism

DOI:  https://doi.org/10.1007/s11095-024-03783-2
Biomedicines. 2024 Sep 26. pii: 2197. [Epub ahead of print]12(10):

How Does Cancer Occur? How Should It Be Treated? Treatment from the Perspective of Alkalization Therapy Based on Science-Based Medicine.

Reo Hamaguchi, Masahide Isowa, Ryoko Narui, Hiromasa Morikawa, Toshihiro Okamoto, Hiromi Wada.

  This review article investigates the relationship between mitochondrial dysfunction and cancer progression, emphasizing the metabolic shifts that promote tumor growth. Mitochondria are crucial for cellular energy production, but they also play a significant role in cancer progression by promoting glycolysis even under oxygen-rich conditions, a phenomenon known as the Warburg effect. This metabolic reprogramming enables cancer cells to maintain an alkaline internal pH and an acidic external environment, which are critical for their proliferation and survival in hypoxic conditions. The article also explores the acidic tumor microenvironment (TME), a consequence of intensive glycolytic activity and proton production by cancer cells. This acidic milieu enhances the invasiveness and metastatic potential of cancer cells and contributes to increased resistance to chemotherapy. Alkalization therapy, which involves neutralizing this acidity through dietary modifications and the administration of alkalizing agents such as sodium bicarbonate, is highlighted as an effective strategy to counteract these adverse conditions and impede cancer progression. Integrating insights from science-based medicine, the review evaluates the effectiveness of alkalization therapy across various cancer types through clinical assessments. Science-based medicine, which utilizes inductive reasoning from observed clinical outcomes, lends support to the hypothesis of metabolic reprogramming in cancer treatment. By addressing both metabolic and environmental disruptions, this review suggests that considering cancer as primarily a metabolic disorder could lead to more targeted and effective treatment strategies, potentially improving outcomes for patients with advanced-stage cancers.

Keywords:  Warburg effect; alkalization therapy; cancer metabolism; glycolysis; mitochondrial dysfunction; oxidative phosphorylation; pH regulation; tumor microenvironment

DOI:  https://doi.org/10.3390/biomedicines12102197
Cell Metab. 2024 Oct 22. pii: S1550-4131(24)00397-8. [Epub ahead of print]

Amino acid is a major carbon source for hepatic lipogenesis.

Yilie Liao, Qishan Chen, Lei Liu, Haipeng Huang, Jingyun Sun, Xiaojie Bai, Chenchen Jin, Honghao Li, Fangfang Sun, Xia Xiao, Yahong Zhang, Jia Li, Weiping Han, Suneng Fu.

  Increased de novo lipogenesis is a hallmark of metabolic dysfunction-associated steatotic liver disease (MASLD) in obesity, but the macronutrient carbon source for over half of hepatic fatty acid synthesis remains undetermined. Here, we discover that dietary protein, rather than carbohydrates or fat, is the primary nutritional risk factor for MASLD in humans. Consistently, ex vivo tracing studies identify amino acids as a major carbon supplier for the tricarboxylic acid (TCA) cycle and lipogenesis in isolated mouse hepatocytes. In vivo, dietary amino acids are twice as efficient as glucose in fueling hepatic fatty acid synthesis. The onset of obesity further drives amino acids into fatty acid synthesis through reductive carboxylation, while genetic and chemical interventions that divert amino acid carbon away from lipogenesis alleviate hepatic steatosis. Finally, low-protein diets (LPDs) not only prevent body weight gain in obese mice but also reduce hepatic lipid accumulation and liver damage. Together, this study uncovers the significant role of amino acids in hepatic lipogenesis and suggests a previously unappreciated nutritional intervention target for MASLD.

Keywords:  DNL; MASH; MASLD; NAFLD; amino acids; dietary protein; glucose; glutamine; lipogenesis

DOI:  https://doi.org/10.1016/j.cmet.2024.10.001
Genes (Basel). 2024 Oct 14. pii: 1316. [Epub ahead of print]15(10):

PRODH Regulates Tamoxifen Resistance through Ferroptosis in Breast Cancer Cells.

Ping Zhang, Na Qian, Haigen Lai, Shu Chen, Kuaiying Wu, Xiaofeng Luo, Bo Lei, Mengqi Liu, Jiajun Cui.

  BACKGROUND: Estrogen receptor-positive breast cancer accounts for around 70% of all cases. Tamoxifen, an anti-estrogenic inhibitor, is the primary drug used for this type of breast cancer treatment. However, tamoxifen resistance is a major challenge in clinics. Metabolic reprogramming, an emerging hallmark of cancer, plays a key role in cancer initiation, progression, and therapy resistance. The metabolism of non-essential amino acids such as serine, proline, and glutamine is involved in tumor metabolism reprogramming. Although the association of glutamine metabolism with tamoxifen resistance has been well established, the role of proline metabolism and its critical enzyme PRODH is unknown.OBJECTIVE: The aim of this study is to explore the role and mechanism of PRODH in tamoxifen resistance in breast cancer cells.
METHODS: PRODH and GPX4 expressions in tamoxifen-resistant cells were detected using real-time PCR and Western blot analysis. The breast cells' response to tamoxifen was measured using MTT assays. Trans-well assays were used to detect cell migration and invasion. A Xenograft tumor assay was used to detect the role of PRODH in tumor growth. Reactive oxygen species were measured using flow cytometry.
RESULTS: PRODH expression is reduced in tamoxifen-resistant cells, and its overexpression enhances tamoxifen response in vitro and in vivo. Conversely, PRODH knockdown confers tamoxifen resistance in tamoxifen-sensitive cells. Mechanistic studies show that ferroptosis is inhibited in tamoxifen-resistant cells and overexpression of PRODH restores the ferroptosis in tamoxifen-resistant cells. Moreover, Ferrostatin-1 (Fer-1), the ferroptosis inhibitor, reversed the effect of PRODH on tamoxifen resistance.
CONCLUSIONS: These findings suggest that PRODH regulates tamoxifen resistance by regulating ferroptosis in tamoxifen-resistant cells.

Keywords:  PRODH; ferroptosis; proline; tamoxifen resistance

DOI:  https://doi.org/10.3390/genes15101316
Int Immunopharmacol. 2024 Oct 24. pii: S1567-5769(24)01934-9. [Epub ahead of print]143(Pt 2): 113412

Targeting metabolic pathway enhance CAR-T potency for solid tumor.

Wenying Li, Jiannan Chen, Zhigang Guo.

  Chimeric antigen receptor (CAR) T cells have great potential in cancer therapy, particularly in treating hematologic malignancies. However, their efficacy in solid tumors remains limited, with a significant proportion of patients failing to achieve long-term complete remission. One major challenge is the premature exhaustion of CAR-T cells, often due to insufficient metabolic energy. The survival, function and metabolic adaptation of CAR-T cells are key determinants of their therapeutic efficacy. We explore how targeting metabolic pathways in the tumor microenvironment can enhance CAR-T cell therapy by addressing metabolic competition and immunosuppression that impair CAR-T cell function. Tumors undergo metabolically reprogrammed to meet their rapid proliferation, thereby modulating metabolic pathways in immune cells to promote immunosuppression. The distinct metabolic requirements of tumors and T cells create a competitive environment, affecting the efficacy of CAR-T cell therapy. Recent research on glucose, lipid and amino acid metabolism, along with the interactions between tumor and immune cell metabolism, has revealed that targeting these metabolic processes can enhance antitumor immune responses. Combining metabolic interventions with existing antitumor therapies can fulfill the metabolic demands of immune cells, providing new ideas for tumor immunometabolic therapies. This review discusses the latest advances in the immunometabolic mechanisms underlying tumor immunosuppression, their implications for immunotherapy, and summarizes potential metabolic targets to improve the efficacy of CAR-T therapy.

Keywords:  CAR-T cell therapy; Immunotherapy; Metabolism reprogramming; Tumor microenvironment

DOI:  https://doi.org/10.1016/j.intimp.2024.113412
Cancers (Basel). 2024 Oct 17. pii: 3513. [Epub ahead of print]16(20):

Insights into Metabolic Reprogramming in Tumor Evolution and Therapy.

Ching-Feng Chiu, Jonathan Jaime G Guerrero, Ric Ryan H Regalado, Ma Joy B Zamora, Jiayan Zhou, Kin Israel Notarte, Yu-Wei Lu, Paolo C Encarnacion, Cidne Danielle D Carles, Edrian M Octavo, Dan Christopher I Limbaroc, Charupong Saengboonmee, Shih-Yi Huang.

  Background: Cancer remains a global health challenge, characterized not just by uncontrolled cell proliferation but also by the complex metabolic reprogramming that underlies its development and progression. Objectives: This review delves into the intricate relationship between cancer and its metabolic alterations, drawing an innovative comparison with the cosmological concepts of dark matter and dark energy to highlight the pivotal yet often overlooked role of metabolic reprogramming in tumor evolution. Methods: It scrutinizes the Warburg effect and other metabolic adaptations, such as shifts in lipid synthesis, amino acid turnover, and mitochondrial function, driven by mutations in key regulatory genes. Results: This review emphasizes the significance of targeting these metabolic pathways for therapeutic intervention, outlining the potential to disrupt cancer's energy supply and signaling mechanisms. It calls for an interdisciplinary research approach to fully understand and exploit the intricacies of cancer metabolism, pointing toward metabolic reprogramming as a promising frontier for developing more effective cancer treatments. Conclusion: By equating cancer's metabolic complexity with the enigmatic nature of dark matter and energy, this review underscores the critical need for innovative strategies in oncology, highlighting the importance of unveiling and targeting the "dark energy" within cancer cells to revolutionize future therapy and research.

Keywords:  Warburg effect; cancer; metabolic reprogramming

DOI:  https://doi.org/10.3390/cancers16203513
Mikrochim Acta. 2024 10 28. 191(11): 704

Preparation of D-NCCDs and its application in fluorescent/colorimetric dual-mode discrimination of glutamine enantiomers.

Xuan Liao, Cancan Lu, Yaning Duan, Cuiling Ren, Hongli Chen.

  A new type of carbon dots (D-NCCDs) was synthesized by 3, 5-diaminobenzoic acid, N,N-dimethyl-o-phenylenediamine, and D-cysteine. The morphology and structure of D-NCCDs were investigated by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and FT-IR spectra, and the chirality was characterized by circular dichroism. In the presence of hydrogen peroxide, the fluorescence of D-NCCDs at 487 nm (λex = 410 nm) showed great discrimination ability towards glutamine enantiomers. The ratio of fluorescence intensity (F/F0) to the concentration of D-Gln showed good linearity in the range 0.5-10 mM, with a detection limits of 0.11 mM. Meanwhile, the color of the solution gradually changed from light yellow to yellow-brown. The UV-Vis absorption ratio (A/A0) at 410 nm showed good linearity with the concentration of D-Gln in the range 0.5 to 20 mM; the detection limit is 7.7 μM. But the fluorescence and absorbance of D-NCCDs showed no significant change after the addition of L-glutamine. Thus, fluorescence and colorimetry dual-mode discrimination of glutamine enantiomers was achieved. The fluorescence enantioselectivity of Gln (FL-Gln/FD-Gln) is 1.62, and the colorimetric enantioselectivity of Gln (AD-Gln/AL-Gln) is 2.14. The chiral discrimination mechanism of D-NCCDs to Gln enantiomers was also investigated systematically. This work not only can discriminate glutamine enantiomers with high sensitivity and convenience, but also offers a new strategy for preparing new dual mode chiral nanoprobes.

Keywords:  Carbon dots; Chiral discrimination; Fluorescent/colorimetric dual-mode; Gln enantiomers

DOI:  https://doi.org/10.1007/s00604-024-06788-1
Anticancer Res. 2024 Nov;44(11): 4869-4875

Role of Glutamine Synthetase on Vascular Permeability in Gliomas.

Dandan Wang, Tianwei Song, Zongtao Hu, Hongzhi Wang, Junchao Qian.

  BACKGROUND/AIM: This study aimed to investigate the effect and underlying mechanism of inhibiting glutamine synthetase (GS) on the vascular permeability of gliomas.MATERIALS AND METHODS: C6 glioma rat models were randomly divided into control and L-methionine sulfoximine (MSO) treatment groups. MSO was intraperitoneally injected once every other day for a total of three injections in the MSO group. We assessed the effect of MSO on tumor vascular permeability by tail vein injection of Evans blue dye. GS activity, glutamate (Glu) concentration, glutamine (Gln) concentration, and arginine concentration in tumor tissues were measured using the corresponding kits. qPCR experiments were then conducted to examine the effect of glutamate concentration on N-methyl-D-aspartate (NMDA) receptor expression. Finally, the nitric oxide synthase (NOS) assay kit and the nitric oxide (NO) assay kit were employed to detect NOS activity and NO concentration changes, respectively.
RESULTS: Increased glioma tumor vascular permeability was observed after intraperitoneal injection of MSO; MSO acted as an inhibitor of GS, leading to a decrease in GS activity; increased glutamate levels caused activation of NMDA receptors and further activation of NOS; additionally, elevated NO levels were detected in association with an increase in arginine and NOS.
CONCLUSION: Inhibiting GS results in increased vascular permeability in gliomas, which is associated with elevated NO levels and the vasodilatory effects of NO.

Keywords:  C6; Glutamine synthetase; glioma; vascular permeability

DOI:  https://doi.org/10.21873/anticanres.17312
Sci Rep. 2024 10 28. 14(1): 25815

Glutamine and serum starvation alters the ATP production, oxidative stress, and abundance of mitochondrial RNAs in extracellular vesicles produced by cancer cells.

Maria Bugajova, Martina Raudenska, Klara Hanelova, Jiri Navratil, Jaromir Gumulec, Frantisek Petrlak, Tomas Vicar, Sarka Hrachovinova, Michal Masarik, David Kalfert, Marek Grega, Jan Plzak, Jan Betka, Jan Balvan.

Induction of autophagy represents an effective survival strategy for nutrient-deprived or stressed cancer cells. Autophagy contributes to the modulation of communication within the tumor microenvironment. Here, we conducted a study of the metabolic and signaling implications associated with autophagy induced by glutamine (Gln) and serum starvation and PI3K/mTOR inhibitor and autophagy inducer NVP-BEZ235 (BEZ) in the head and neck squamous cell carcinoma (HNSCC) cell line FaDu. We compared the effect of these different types of autophagy induction on ATP production, lipid peroxidation, mitophagy, RNA cargo of extracellular vesicles (EVs), and EVs-associated cytokine secretome of cancer cells. Both BEZ and starvation resulted in a decline in ATP production. Simultaneously, Gln starvation enhanced oxidative damage of cancer cells by lipid peroxidation. In starved cells, there was a discernible fragmentation of the mitochondrial network coupled with an increase in the presence of tumor susceptibility gene 101 (TSG101) on the mitochondrial membrane, indicative of the sorting of mitochondrial cargo into EVs. Consequently, the abundance of mitochondrial RNAs (mtRNAs) in EVs released by FaDu cells was enhanced. Notably, mtRNAs were also detectable in EVs isolated from the serum of both HNSCC patients and healthy controls. Starvation and BEZ reduced the production of EVs by cancer cells, yet the characteristic molecular profile of these EVs remained unchanged. We also found that alterations in the release of inflammatory cytokines constitute a principal response to autophagy induction. Importantly, the specific mechanism driving autophagy induction significantly influenced the composition of the EVs-associated cytokine secretome.

DOI: https://doi.org/10.1038/s41598-024-73943-2
Cancer Discov. 2024 Oct 31.

Copper drives remodeling of metabolic state and progression of clear cell renal cell carcinoma.

Megan E Bischoff, Behrouz Shamsaei, Juechen Yang, Dina Secic, Bhargav Vemuri, Julie A Reisz, Angelo D'Alessandro, Caterina Bartolacci, Rafal Adamczak, Lucas Schmidt, Jiang Wang, Amelia Martines, Jahnavi Venkat, Vanina Toffessi Tcheuyap, Jacek Biesiada, Catherine A Behrmann, Katherine E Vest, James Brugarolas, Pier Paolo Scaglioni, David R Plas, Krushna C Patra, Shuchi Gulati, Julio A Landero Figueroa, Jarek Meller, John T Cunningham, Maria F Czyzyk-Krzeska.

Copper (Cu) is a cofactor of cytochrome c oxidase (CuCOX), indispensable for aerobic mitochondrial respiration. This study reveals that advanced clear cell renal cell carcinomas (ccRCCs) accumulate Cu, allocating it to CuCOX. Using a range of orthogonal approaches, including metabolomics, lipidomics, isotope-labeled glucose and glutamine flux analysis, and transcriptomics across tumor samples, cell lines, xenografts, and PDX models, combined with genetic and pharmacological interventions, we explored Cu's role in ccRCC. Elevated Cu levels stimulate CuCOX biogenesis, providing bioenergetic and biosynthetic benefits that promote tumor growth. This effect is complemented by glucose-dependent glutathione production, which facilitates detoxification and mitigates Cu-H2O2 toxicity. Single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics reveal increased oxidative metabolism, altered glutathione and Cu metabolism, and diminished HIF activity during ccRCC progression. Thus, Cu drives an integrated oncogenic remodeling of bioenergetics, biosynthesis, and redox homeostasis, fueling ccRCC growth, which can be targeted for new therapeutic approaches.

DOI: https://doi.org/10.1158/2159-8290.CD-24-0187
Small. 2024 Oct 29. e2407555

A Hybrid Alloying Nanozyme-Glutathione Inhibitor Co-Delivery System Initiates a Dual-Disruption on Cancer Redox Homeostasis.

Jue Hou, Hanxiao Bao, Yu Wang, Qiaomei Zhou, Jiayi Chen, Guohua Pan, Guoqiao Xu, Jinguo Zhang, Guping Tang, Hongzhen Bai.

  Altered redox homeostasis has long been observed in cancer cells, which can be exploited for therapeutic benefits. However, reactive oxygen species (ROS) pleiotropy coupling with reductive adaptation in cancer cells poses a formidable challenge for redox dyshomeostasis-based cancer therapy. Herein, a AuPd alloying nanozyme-glutathione (GSH) biosynthesis inhibitor co-delivery system (B-BMES) is developed using dendritic SiO2 as a matrix to target cancer redox homeostasis. By optimizing element composition, the alloying nanozyme in B-BMES exhibits a potent peroxidase (POD)-like activity to trigger ROS insults-mediated redox dyshomeostasis. Such a POD functionality is attributed to the optimized electronic structure and catalytic activity. Simultaneously, the B-BMES abrogates the reductive adaptation by exerting its molecule-targeted GSH suppression, thereby achieving a dual-disruption on cancer redox homeostasis. Camouflaging B-BMES with tumor-homologous cytomembrane, a hybrid nanosystem with biological stability and tumor-targeting ability is further fabricated, which initiates a safe, precise redox disruption-based cancer therapy and sensibilizes standard chemotherapy.

Keywords:  cell membrane; drug delivery; nanocatalytic medicine; peroxidase‐like nanozyme

DOI:  https://doi.org/10.1002/smll.202407555
bioRxiv. 2024 Sep 29. pii: 2024.09.29.615681. [Epub ahead of print]

Glutamate Transport Proteins and Metabolic Enzymes are Poor Prognostic Factors in Invasive Lobular Carcinoma.

Todd A Young, Shaymaa Bahnassy, Theresa C Abalum, Eden A Pope, Amanda Torres Rivera, Aileen I Fernandez, Ayodeji O Olukoya, Dua Mobin, Suman Ranjit, Nicole E Libbey, Sonali Persaud, Aaron M Rozeboom, Krysta Chaldekas, Brent T Harris, Zeynep Madak-Erdogan, Joseph L Sottnik, Matthew J Sikora, Rebecca B Riggins.

  Invasive Lobular Carcinoma (ILC) is a subtype of breast cancer characterized by distinct biological features, and limited glucose uptake coupled with increased reliance on amino acid and lipid metabolism. Our prior studies highlight the importance of glutamate as a key regulator of ILC tumor growth and therapeutic response. Here we examine the expression of four key proteins involved in glutamate transport and metabolism - SLC3A2, SLC7A11, GPX4, and GLUD1/2 - in a racially diverse cohort of 72 estrogen receptor-positive (ER+) ILC and 50 ER+ invasive ductal carcinoma, no special type (IDC/NST) patients with primary disease. All four proteins are associated with increased tumor size in ILC, but not IDC/NST, with SLC3A2 also specifically linked to shorter overall survival and the presence of comorbidities in ILC. Notably, GLUD1/2 expression is associated with ER expression in ILC, and is most strongly associated with increased tumor size and stage in Black women with ILC from our cohort and TCGA. We further explore the effects of GLUD1 inhibition in endocrine therapy-resistant ILC cells using the small-molecule inhibitor R162, which reduces ER protein levels, increases reactive oxygen species, and inhibits oxidative phosphorylation. These findings highlight a potentially important role for glutamate metabolism in ILC, particularly for Black women, and position several of these glutamate-handling proteins as potential targets for therapeutic intervention in ILC.

Keywords:  GLUD1; GPX4; Invasive lobular carcinoma; disparities; glutamate metabolism

DOI:  https://doi.org/10.1101/2024.09.29.615681
Methods Mol Biol. 2025 ;2853 49-69

Application of CRISPR/Cas9 Genome Editing to Improve Recombinant Protein Production in CHO Cells.

Lise Marie Grav, Johan Blatt Rojek, Karen Julie la Cour Karottki, Jae Seong Lee, Helene Faustrup Kildegaard.

  Genome editing has become an important aspect of Chinese hamster ovary (CHO) cell line engineering for improving the production of recombinant protein therapeutics. Currently, the engineering focus is directed toward expanding product diversity while controlling and improving product quality and yields. In this chapter, we present our protocol for using the genome editing tool Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) to knock out engineering target genes in CHO cells. As an example, we describe how to knock out the glutamine synthetase (GS) gene, which increases the selection efficiency of the GS-mediated gene amplification system.

Keywords:  CRISPR; Cas9; Chinese hamster ovary (CHO) cells; Genome editing; Glutamine synthetase; Knockout; Recombinant protein production

DOI:  https://doi.org/10.1007/978-1-0716-4104-0_5