Downregulation of Glutamine Synthetase, not glutaminolysis, is responsible for glutamine addiction in Notch1-driven acute lymphoblastic leukemia

Notch signaling pathway in cancer: from mechanistic insights to targeted therapies

Notch signaling, renowned for its role in regulating cell fate, organ development, and tissue homeostasis across metazoans, is highly conserved throughout evolution. The Notch receptor and its ligands are transmembrane proteins containing epidermal growth factor-like repeat sequences, typically necessitating receptor-ligand interaction to initiate classical Notch signaling transduction. Accumulating evidence indicates that the Notch signaling pathway serves as both an oncogenic factor and a tumor suppressor in various cancer types. Dysregulation of this pathway promotes epithelial-mesenchymal transition and angiogenesis in malignancies, closely linked to cancer proliferation, invasion, and metastasis. Furthermore, the Notch signaling pathway contributes to maintaining stem-like properties in cancer cells, thereby enhancing cancer invasiveness. The regulatory role of the Notch signaling pathway in cancer metabolic reprogramming and the tumor microenvironment suggests its pivotal involvement in balancing oncogenic and tumor suppressive effects. Moreover, the Notch signaling pathway is implicated in conferring chemoresistance to tumor cells. Therefore, a comprehensive understanding of these biological processes is crucial for developing innovative therapeutic strategies targeting Notch signaling. This review focuses on the research progress of the Notch signaling pathway in cancers, providing in-depth insights into the potential mechanisms of Notch signaling regulation in the occurrence and progression of cancer. Additionally, the review summarizes pharmaceutical clinical trials targeting Notch signaling for cancer therapy, aiming to offer new insights into therapeutic strategies for human malignancies.

Multi-Omics Reveals the Genetic and Metabolomic Architecture of Chirality Directed Stem Cell Lineage Diversification

Chirality-directed stem-cell-fate determination involves coordinated transcriptional and metabolomics programming that is only partially understood. Here, using high-throughput transcriptional-metabolic profiling and pipeline network analysis, the molecular architecture of chirality-guided mesenchymal stem cell lineage diversification is revealed. A total of 4769 genes and 250 metabolites are identified that are significantly biased by the biomimetic chiral extracellular microenvironment (ECM). Chirality-dependent energetic metabolism analysis has revealed that glycolysis is preferred during left-handed ECM-facilitated osteogenic differentiation, whereas oxidative phosphorylation is favored during right-handed ECM-promoted adipogenic differentiation. Stereo-specificity in the global metabolite landscape is also demonstrated, in which amino acids are enriched in left-handed ECM, while ether lipids and nucleotides are enriched in right-handed ECM. Furthermore, chirality-ordered transcriptomic-metabolic regulatory networks are established, which address the role of positive feedback loops between key genes and central metabolites in driving lineage diversification. The highly integrated genotype-phenotype picture of stereochemical selectivity would provide the fundamental principle of regenerative material design.

TIM-3/Galectin-9 interaction and glutamine metabolism in AML cell lines, HL-60 and THP-1

BACKGROUND

T cell immunoglobulin and mucin-domain containing-3 (TIM-3) is a cell surface molecule that was first discovered on T cells. However, recent studies revealed that it is also highly expressed in acute myeloid leukemia (AML) cells and it is related to AML progression. As, Glutamine appears to play a prominent role in malignant tumor progression, especially in their myeloid group, therefore, in this study we aimed to evaluate the relation between TIM-3/Galectin-9 axis and glutamine metabolism in two types of AML cell lines, HL-60 and THP-1.

METHODS

Cell lines were cultured in RPMI 1640 which supplemented with 10% FBS and 1% antibiotics. 24, 48, and 72 h after addition of recombinant Galectin-9 (Gal-9), RT-qPCR analysis, RP-HPLC and gas chromatography techniques were performed to evaluate the expression of glutaminase (GLS), glutamate dehydrogenase (GDH) enzymes, concentration of metabolites; Glutamate (Glu) and alpha-ketoglutarate (α-KG) in glutaminolysis pathway, respectively. Western blotting and MTT assay were used to detect expression of mammalian target of rapamycin complex (mTORC) as signaling factor, GLS protein and cell proliferation rate, respectively.

RESULTS

The most mRNA expression of GLS and GDH in HL-60 cells was seen at 72 h after Gal-9 treatment (p = 0.001, p = 0.0001) and in THP-1 cell line was observed at 24 h after Gal-9 addition (p = 0.001, p = 0.0001). The most mTORC and GLS protein expression in HL-60 and THP-1 cells was observed at 72 and 24 h after Gal-9 treatment (p = 0.0001), respectively. MTT assay revealed that Gal-9 could promote cell proliferation rate in both cell lines (p = 0.001). Glu concentration in HL-60 and α-KG concentration in both HL-60 (p = 0.03) and THP-1 (p = 0.0001) cell lines had a decreasing trend. But, Glu concentration had an increasing trend in THP-1 cell line (p = 0.0001).

CONCLUSION

Taken together, this study suggests TIM-3/Gal-9 interaction could promote glutamine metabolism in HL-60 and THP-1 cells and resulting in AML development.

Comprehensive analysis based on glycolytic and glutaminolytic pathways signature for predicting prognosis and immunotherapy in ovarian cancer

Background: Our study attempts to develop and identify an aerobic glycolysis and glutamine-related genes (AGGRGs) signature for estimating prognostic effectively of ovarian cancer (OV) patients. Materials & methods: OV related data were extracted from the multiple public databases, including TCGA-OV, GSE26193, GSE63885, and ICGC-OV. A consistent clustering approach was used to characterize the subtypes associated with AGGRGs. LASSO Cox regressions was utilized to construct the prognosis signatures of AGGRGs. In addition, GSE26193, GSE63885 and ICGC-OV served as independent external cohorts to assess the reliability of the model. In vitro and in vivo experiments were conducted to study the role of AAK1 in the malignant progression and glutamine metabolism of OV, and assessed its therapeutic potential for treating OV patients. Results: OV patients could be separated into four subtypes (quiescent, glycolysis, glutaminolytic, and mixed subtypes). The survival outcome of glutaminolytic subtype was notably worse than the glycolytic subtype. Besides, we identified eight AGGRGs (AAK1, GJB6, HMGN5, LPIN3, INTS6L, PPOX, SPAG4, and ZNF316) to establish a prognostic signature for OV patients. Comprehensive analysis revealed that the signature risk score served as an independent prognostic factor for OV. Additionally, high-risk OV patients were less sensitive to platinum and, conversely, were proved to be more responsive to immunotherapy than low-risk score. In cytological experiments, we found that AAK1 could promote cancer progression and glutamine metabolism via activating the Notch3 pathway in OV cells. Furthermore, knockdown of AAK1 significantly inhibited tumor growth and weight, decreased lung metastases, and ultimately extended the survival time of the nude mice. Conclusions: The prognostic signature of AGGRGs constructed could efficiently estimate the prognosis and immunotherapy effectiveness of OV patients. In addition, AAK1 may represent a promising therapeutic target for OV.

Glutamine synthetase and hepatocellular carcinoma

Glutamine synthetase (GS) is an enzyme that converts ammonia and glutamate to glutamine using adenosine triphosphate. GS is expressed in the brain, kidney, and liver tissues under normal physiological conditions. GS is involved in abnormal lipid metabolism of the liver by catalyzing de novo synthesis of glutamine, thereby inducing liver inflammation. Metabolic dysfunction-associated steatotic liver diseases (MASLD), such as Metabolic Associated Fatty Liver Disease and Metabolic Associated Steato Hepatitis, are considered risk factors for HCC. GS may also be involved in the development and progression of hepatocellular carcinoma (HCC) through other signaling pathways, including the rapamycin (mTOR) and Wnt/β-catenin signaling pathways. Furthermore, the correct combination of HSP70, GPC3, and GS can improve the accuracy and precision of HCC diagnosis. However, the prognostic value of GS in different HCC populations remains controversial. The expression of GS affects the sensitivity of HCC cells to radiotherapy and chemotherapy. In addition, immunotherapy has been approved for the treatment of advanced HCC. This article delves into the development and application of GS in HCC, laying a theoretical foundation for the subsequent exploration of GS as a potential target for treating HCC.

Optimization of L-glutaminase production by Monascus ruber URM 8542 isolated from ice cream industrial effluent

L-glutaminase is a hydrolytic enzyme with wide biotechnological applications. Mostly, these enzymes are employed in the feed industry for flavor enhancement and acrylamide mitigation. Also, L-glutaminase may have antiviral and antineoplastic effects making it a good choice for pharmaceutical applications. In this study, the strain Monascus ruber URM 8542 was identified through classical and molecular taxonomy using partial sequencing of β-tubulin and calmodulin genes. Subsequently, the optimal culture conditions were evaluated by submerged fermentation (L-glutamine 10 g.L- 1) for L-glutaminase excretion. The isolate was identified as M. ruber URM 8542 which showed significant extracellular enzyme production with a yield of 11.4 times in relation to the specific activity of intracellular L-glutaminase. Regarding the optimization experiments, several factors such as L-glutamine concentration, temperature, and pH were compared using a full factorial design (23). The concentrations greater than 1% proved to be significantly better for glutaminase production (R2 = 0.9077). Additionally, the L-glutaminase was optimally active at pH 7.0 and 30 ºC. The L-glutaminase was remarkably stable across an alkaline pH range (7.0-8.0) and had a thermal stability ranging from 30 ºC to 60 ºC for 1 h. Taken together, these findings suggest that the L-glutaminase produced by M. ruber is a promising candidate for pharmacological application, although further studies need to be performed. To the best of our knowledge, this is the first report of L-glutaminase production by Monascus ruber.

In vitro simulation of the acute lymphoblastic leukemia niche: a critical view on the optimal approximation for drug testing

Acute lymphoblastic leukemia with the worst prognosis is related to minimal residual disease. Minimal residual disease not only depends on the individual peculiarities of leukemic clones but also reflects the protective role of the acute lymphoblastic leukemia microenvironment. In this review, we discuss in detail cell-to-cell interactions in the 2 leukemic niches, more explored bone marrow and less studied extramedullary adipose tissue. A special emphasis is given to multiple ways of interactions of acute lymphoblastic leukemia cells with the bone marrow or extramedullary adipose tissue microenvironment, indicating observed differences in B- and T-cell-derived acute lymphoblastic leukemia behavior. This analysis argued for the usage of coculture systems for drug testing. Starting with a review of available sources and characteristics of acute lymphoblastic leukemia cells, mesenchymal stromal cells, endothelial cells, and adipocytes, we have then made an update of the available 2-dimensional and 3-dimensional systems, which bring together cellular elements, components of the extracellular matrix, or its imitation. We discussed the most complex available 3-dimensional systems like "leukemia-on-a-chip," which include either a prefabricated microfluidics platform or, alternatively, the microarchitecture, designed by using the 3-dimensional bioprinting technologies. From our analysis, it follows that for preclinical antileukemic drug testing, in most cases, intermediately complex in vitro cell systems are optimal, such as a "2.5-dimensional" coculture of acute lymphoblastic leukemia cells with niche cells (mesenchymal stromal cells, endothelial cells) plus matrix components or scaffold-free mesenchymal stromal cell organoids, populated by acute lymphoblastic leukemia cells. Due to emerging evidence for the correlation of obesity and poor prognosis, a coculture of adipocytes with acute lymphoblastic leukemia cells as a drug testing system is gaining shape.

Dietary Manipulation of Amino Acids for Cancer Therapy

Cancer cells cannot proliferate and survive unless they obtain sufficient levels of the 20 proteinogenic amino acids (AAs). Unlike normal cells, cancer cells have genetic and metabolic alterations that may limit their capacity to obtain adequate levels of the 20 AAs in challenging metabolic environments. However, since normal diets provide all AAs at relatively constant levels and ratios, these potentially lethal genetic and metabolic defects are eventually harmless to cancer cells. If we temporarily replace the normal diet of cancer patients with artificial diets in which the levels of specific AAs are manipulated, cancer cells may be unable to proliferate and survive. This article reviews in vivo studies that have evaluated the antitumor activity of diets restricted in or supplemented with the 20 proteinogenic AAs, individually and in combination. It also reviews our recent studies that show that manipulating the levels of several AAs simultaneously can lead to marked survival improvements in mice with metastatic cancers.

Targeting Glutaminolysis Shows Efficacy in Both Prednisolone-Sensitive and in Metabolically Rewired Prednisolone-Resistant B-Cell Childhood Acute Lymphoblastic Leukaemia Cells

The prognosis for patients with relapsed childhood acute lymphoblastic leukaemia (cALL) remains poor. The main reason for treatment failure is drug resistance, most commonly to glucocorticoids (GCs). The molecular differences between prednisolone-sensitive and -resistant lymphoblasts are not well-studied, thereby precluding the development of novel and targeted therapies. Therefore, the aim of this work was to elucidate at least some aspects of the molecular differences between matched pairs of GC-sensitive and -resistant cell lines. To address this, we carried out an integrated transcriptomic and metabolomic analysis, which revealed that lack of response to prednisolone may be underpinned by alterations in oxidative phosphorylation, glycolysis, amino acid, pyruvate and nucleotide biosynthesis, as well as activation of mTORC1 and MYC signalling, which are also known to control cell metabolism. In an attempt to explore the potential therapeutic effect of inhibiting one of the hits from our analysis, we targeted the glutamine-glutamate-α-ketoglutarate axis by three different strategies, all of which impaired mitochondrial respiration and ATP production and induced apoptosis. Thereby, we report that prednisolone resistance may be accompanied by considerable rewiring of transcriptional and biosynthesis programs. Among other druggable targets that were identified in this study, inhibition of glutamine metabolism presents a potential therapeutic approach in GC-sensitive, but more importantly, in GC-resistant cALL cells. Lastly, these findings may be clinically relevant in the context of relapse-in publicly available datasets, we found gene expression patterns suggesting that in vivo drug resistance is characterised by similar metabolic dysregulation to what we found in our in vitro model.

Glutamine synthetase expression rescues human dendritic cell survival in a glutamine-deprived environment

Introduction

Glutamine deficiency is a well-known feature of the tumor environment. Here we analyzed the impact of glutamine deprivation on human myeloid cell survival and function.

Methods

Different types of myeloid cells were cultured in the absence or presence of glutamine and/or with L-methionine-S-sulfoximine (MSO), an irreversible glutamine synthetase (GS) inhibitor. GS expression was analyzed on mRNA and protein level. GS activity and the conversion of glutamate to glutamine by myeloid cells was followed by 13C tracing analyses.

Results

The absence of extracellular glutamine only slightly affected postmitotic human monocyte to dendritic cell (DC) differentiation, function and survival. Similar results were obtained for monocyte-derived macrophages. In contrast, proliferation of the monocytic leukemia cell line THP-1 was significantly suppressed. While macrophages exhibited high constitutive GS expression, glutamine deprivation induced GS in DC and THP-1. Accordingly, proliferation of THP-1 was rescued by addition of the GS substrate glutamate and 13C tracing analyses revealed conversion of glutamate to glutamine. Supplementation with the GS inhibitor MSO reduced the survival of DC and macrophages and counteracted the proliferation rescue of THP-1 by glutamate.

Discussion

Our results show that GS supports myeloid cell survival in a glutamine poor environment. Notably, in addition to suppressing proliferation and survival of tumor cells, the blockade of GS also targets immune cells such as DCs and macrophages.

Formyl-Peptide Receptor 2 Signaling Redirects Glucose and Glutamine into Anabolic Pathways in Metabolic Reprogramming of Lung Cancer Cells

Glucose and glutamine play a crucial role in the metabolic reprogramming of cancer cells. Proliferating cells metabolize glucose in the aerobic glycolysis for energy supply, and glucose and glutamine represent the primary sources of carbon atoms for the biosynthesis of nucleotides, amino acids, and lipids. Glutamine is also an important nitrogen donor for the production of nucleotides, amino acids, and nicotinamide. Several membrane receptors strictly control metabolic reprogramming in cancer cells and are considered new potential therapeutic targets. Formyl-peptide receptor 2 (FPR2) belongs to a small family of GPCRs and is implicated in many physiopathological processes. Its stimulation induces, among other things, NADPH oxidase-dependent ROS generation that, in turn, contributes to intracellular signaling. Previously, by phosphoproteomic analysis, we observed that numerous proteins involved in energetic metabolism are uniquely phosphorylated upon FPR2 stimulation. Herein, we investigated the role of FPR2 in cell metabolism, and we observed that the concentrations of several metabolites associated with the pentose phosphate pathway (PPP), tricarboxylic acid cycle, nucleotide synthesis, and glutamine metabolism, were significantly enhanced in FPR2-stimulated cells. In particular, we found that the binding of specific FPR2 agonists: (i) promotes NADPH production; (ii) activates the non-oxidative phase of PPP; (iii) induces the expression of the ASCT2 glutamine transporter; (iv) regulates oxidative phosphorylation; and (v) induces the de novo synthesis of pyrimidine nucleotides, which requires FPR2-dependent ROS generation.

Amino acid metabolism: challenges and opportunities for the therapeutic treatment of leukemia and lymphoma

Leukemia and lymphoma-the most common hematological malignant diseases-are often accompanied by complications such as drug resistance, refractory diseases and relapse. Amino acids (AAs) are important energy sources for malignant cells. Tumor-mediated AA metabolism is associated with the immunosuppressive properties of the tumor microenvironment, thereby assisting malignant cells to evade immune surveillance. Targeting abnormal AA metabolism in the tumor microenvironment may be an effective therapeutic approach to address the therapeutic challenges of leukemia and lymphoma. Here, we review the effects of glutamine, arginine and tryptophan metabolism on tumorigenesis and immunomodulation, and define the differences between tumor cells and immune effector cells. We also comment on treatments targeting these AA metabolism pathways in lymphoma and leukemia and discuss how these treatments have profound adverse effects on tumor cells, but leave the immune cells unaffected or mildly affected.

Deciphering Metabolic Adaptability of Leukemic Stem Cells

Therapeutic targeting of leukemic stem cells is widely studied to control leukemia. An emerging approach gaining popularity is altering metabolism as a potential therapeutic opportunity. Studies have been carried out on hematopoietic and leukemic stem cells to identify vulnerable pathways without impacting the non-transformed, healthy counterparts. While many metabolic studies have been conducted using stem cells, most have been carried out in vitro or on a larger population of progenitor cells due to challenges imposed by the low frequency of stem cells found in vivo. This creates artifacts in the studies carried out, making it difficult to interpret and correlate the findings to stem cells directly. This review discusses the metabolic difference seen between hematopoietic stem cells and leukemic stem cells across different leukemic models. Moreover, we also shed light on the advancements of metabolic techniques and current limitations and areas for additional research of the field to study stem cell metabolism.

Inhibition of mitochondrial complex I reverses NOTCH1-driven metabolic reprogramming in T-cell acute lymphoblastic leukemia

T-cell acute lymphoblastic leukemia (T-ALL) is commonly driven by activating mutations in NOTCH1 that facilitate glutamine oxidation. Here we identify oxidative phosphorylation (OxPhos) as a critical pathway for leukemia cell survival and demonstrate a direct relationship between NOTCH1, elevated OxPhos gene expression, and acquired chemoresistance in pre-leukemic and leukemic models. Disrupting OxPhos with IACS-010759, an inhibitor of mitochondrial complex I, causes potent growth inhibition through induction of metabolic shut-down and redox imbalance in NOTCH1-mutated and less so in NOTCH1-wt T-ALL cells. Mechanistically, inhibition of OxPhos induces a metabolic reprogramming into glutaminolysis. We show that pharmacological blockade of OxPhos combined with inducible knock-down of glutaminase, the key glutamine enzyme, confers synthetic lethality in mice harboring NOTCH1-mutated T-ALL. We leverage on this synthetic lethal interaction to demonstrate that IACS-010759 in combination with chemotherapy containing L-asparaginase, an enzyme that uncovers the glutamine dependency of leukemic cells, causes reduced glutaminolysis and profound tumor reduction in pre-clinical models of human T-ALL. In summary, this metabolic dependency of T-ALL on OxPhos provides a rational therapeutic target.

The Role of Amino Acids in the Crosstalk Between Mesenchymal Stromal Cells and Neoplastic Cells in the Hematopoietic Niche

Within the bone marrow hematopoietic cells are in close connection with mesenchymal stromal cells (MSCs), which influence the behavior and differentiation of normal or malignant lymphoid and myeloid cells. Altered cell metabolism is a hallmark of cancer, and changes in nutrient pools and fluxes are important components of the bidirectional communication between MSCs and hematological cancer cells. Among nutrients, amino acids play a significant role in cancer progression and chemo-resistance. Moreover, selected types of cancer cells are extremely greedy for glutamine, and significantly deplete the extracellular pool of the amino acid. As a consequence, this influences the behavior of MSCs in terms of either cytokine/chemokine secretion or differentiation potential. Additionally, a direct nutritional interaction exists between MSCs and immune cells. In particular, selected subpopulations of lymphocytes are dependent upon selected amino acids, such as arginine and tryptophan, for full differentiation and competence. This review describes and discusses the nutritional interactions existing in the neoplastic bone marrow niche between MSCs and other cell types, with a particular emphasis on cancer cells and immune cells. These relationships are discussed in the perspective of potential novel therapeutic strategies based on the interference on amino acid metabolism or intercellular fluxes.

Overcoming Glucocorticoid Resistance in Acute Lymphoblastic Leukemia: Repurposed Drugs Can Improve the Protocol

Glucocorticoids (GCs) are a central component of multi-drug treatment protocols against T and B acute lymphoblastic leukemia (ALL), which are used intensively during the remission induction to rapidly eliminate the leukemic blasts. The primary response to GCs predicts the overall response to treatment and clinical outcome. In this review, we have critically analyzed the available data on the effects of GCs on sensitive and resistant leukemic cells, in order to reveal the mechanisms of GC resistance and how these mechanisms may determine a poor outcome in ALL. Apart of the GC resistance, associated with a decreased expression of receptors to GCs, there are several additional mechanisms, triggered by alterations of different signaling pathways, which cause the metabolic reprogramming, with an enhanced level of glycolysis and oxidative phosphorylation, apoptosis resistance, and multidrug resistance. Due to all this, the GC-resistant ALL show a poor sensitivity to conventional chemotherapeutic protocols. We propose pharmacological strategies that can trigger alternative intracellular pathways to revert or overcome GC resistance. Specifically, we focused our search on drugs, which are already approved for treatment of other diseases and demonstrated anti-ALL effects in experimental pre-clinical models. Among them are some “truly” re-purposed drugs, which have different targets in ALL as compared to other diseases: cannabidiol, which targets mitochondria and causes the mitochondrial permeability transition-driven necrosis, tamoxifen, which induces autophagy and cell death, and reverts GC resistance through the mechanisms independent of nuclear estrogen receptors (“off-target effects”), antibiotic tigecycline, which inhibits mitochondrial respiration, causing energy crisis and cell death, and some anthelmintic drugs. Additionally, we have listed compounds that show a classical mechanism of action in ALL but are not used still in treatment protocols: the BH3 mimetic venetoclax, which inhibits the anti-apoptotic protein Bcl-2, the hypomethylating agent 5-azacytidine, which restores the expression of the pro-apoptotic BIM, and compounds targeting the PI3K-Akt-mTOR axis. Accordingly, these drugs may be considered for the inclusion into chemotherapeutic protocols for GC-resistant ALL treatments.