ITD mutation in FLT3 tyrosine kinase promotes Warburg effect and renders therapeutic sensitivity to glycolytic inhibition

Tumor-targeted nano-assemblies for energy-blocking cocktail therapy in cancer

Starvation therapy aims to "starve" tumor cells by cutting off their nutritional supply. However, due to the complex and varied energy metabolism of tumors, targeting a single nutrient supply often fails to yield significant therapeutic benefits. This study proposes a tumor energy cocktail therapy that combines metformin, an oxidative phosphorylation inhibitor, with 2-deoxy-d-glucose (2-DG), a glycolysis inhibitor, to target tumor cells. To minimize the dosage of both drugs, we have developed a drug delivery strategy that prepared metformin as a nanoderivative, denoted as MA-dots. These MA-dots not only preserve the antitumor properties of metformin but also serve as a targeted delivery platform for 2-DG, ensuring its direct reach to the tumor site. Upon reaching the acidic tumor environment, the composite disintegrates, releasing 2-DG to inhibit glycolysis by targeting hexokinase 2 (HK2), the key enzyme in glycolysis, while MA-dots inhibit mitochondrial OXPHOS. This dual action significantly reduces ATP production in tumor cells, leading to apoptosis. In human lung tumor cells, the half-maximal inhibitory concentration (IC50) of 2-DG@MA-dots was significantly lower than that of either metformin or 2-DG alone, showing a nearly 100-fold and 30-fold reduction in IC50 values to 11.78 µg mL-1, from 1159 µg mL-1 and 351.20 µg mL-1, respectively. In studies with A549 tumor-bearing mice, the combination of low-dose 2-DG and metformin did not impede tumor growth, whereas 2-DG@MA-dots markedly decreased tumor volume, with the mean final tumor volume in the combination treatment group being approximately 89 times greater than that in the 2-DG@MA-dot group. STATEMENT OF SIGNIFICANCE: Metformin is a promising antitumor agent capable of modulating mitochondrial oxidative phosphorylation to inhibit cancer growth. However, its antitumor efficacy is limited when used alone due to compensatory energy mechanisms. Hence, we introduced glycolysis inhibitor 2-deoxy-d-glucose (2-DG) to inhibit an alternative tumor energy pathway. In our study, we developed a drug delivery strategy using metformin-derived nanomedicine (MA-dots) to load 2-DG. This approach enables the co-delivery of both drugs and their synergistic effect at the tumor site, disrupting both energy pathways and introducing an innovative "energy cocktail therapy".

Key role of glutamine metabolism in persistence of leukemic cells upon exposition to FLT3 tyrosine kinase inhibitors

Acute myeloid leukemias are a group of hematological malignancies characterized by a poor prognosis for survival. The discovery of oncogenic mutations in the FMS-like tyrosine kinase 3 (FLT3) gene has led to the development of tyrosine kinase inhibitors such as quizartinib. However, achieving complete remission in patients remains challenging because these new tyrosine kinase inhibitors (TKIs) are unable to completely eradicate all leukemic cells. Residual leukemic cells persist during quizartinib treatment, leading to the rapid emergence of drug-resistant leukemia. Given that mitochondrial oxidative metabolism promotes the survival of leukemic cells after exposure to multiple anticancer drugs, we characterized the metabolism of leukemic cells that persisted during quizartinib treatment and developed metabolic strategies to eradicate them. In our study, employing biochemical and metabolomics approaches, we confirmed that the survival of leukemic cells treated with FLT3 inhibitors critically depends on maintaining mitochondrial metabolism, specifically through glutamine oxidation. We uncovered a synergistic interaction between the FLT3 inhibitor quizartinib and L-asparaginase, operating through antimetabolic mechanisms. Utilizing various models of persistent leukemia, we demonstrated that leukemic cells resistant to quizartinib are susceptible to L-asparaginase. This combined therapeutic strategy shows promise in reducing the development of resistance to FLT3 inhibitors, offering a potential strategy to enhance treatment outcomes.

Application of omics in the diagnosis, prognosis, and treatment of acute myeloid leukemia

Acute myeloid leukemia (AML) is the most frequent leukemia in adults with a high mortality rate. Current diagnostic criteria and selections of therapeutic strategies are generally based on gene mutations and cytogenetic abnormalities. Chemotherapy, targeted therapies, and hematopoietic stem cell transplantation (HSCT) are the major therapeutic strategies for AML. Two dilemmas in the clinical management of AML are related to its poor prognosis. One is the inaccurate risk stratification at diagnosis, leading to incorrect treatment selections. The other is the frequent resistance to chemotherapy and/or targeted therapies. Genomic features have been the focus of AML studies. However, the DNA-level aberrations do not always predict the expression levels of genes and proteins and the latter is more closely linked to disease phenotypes. With the development of high-throughput sequencing and mass spectrometry technologies, studying downstream effectors including RNA, proteins, and metabolites becomes possible. Transcriptomics can reveal gene expression and regulatory networks, proteomics can discover protein expression and signaling pathways intimately associated with the disease, and metabolomics can reflect precise changes in metabolites during disease progression. Moreover, omics profiling at the single-cell level enables studying cellular components and hierarchies of the AML microenvironment. The abundance of data from different omics layers enables the better risk stratification of AML by identifying prognosis-related biomarkers, and has the prospective application in identifying drug targets, therefore potentially discovering solutions to the two dilemmas. In this review, we summarize the existing AML studies using omics methods, both separately and combined, covering research fields of disease diagnosis, risk stratification, prognosis prediction, chemotherapy, as well as targeted therapy. Finally, we discuss the directions and challenges in the application of multi-omics in precision medicine of AML. Our review may inspire both omics researchers and clinical physicians to study AML from a different angle.

The metabolic fuel of paroxysmal nocturnal haemoglobinuria

Metabolic reprogramming has been investigated in haematological malignancies. To date, a few studies have analysed the metabolic profile of paroxysmal nocturnal haemoglobinuria (PNH). The study by Chen and colleagues sheds light on the involvement of metabolic changes in the proliferation of PNH clones. Commentary on: Chen et al. The histone demethylase JMJD1C regulates CPS1 expression and promotes the proliferation of PNH clones through cell metabolic reprogramming. Br J Haematol 2024;204:2468-2479.

A succinylation switch to maligancy: SUCLG1, mitochondrial transcription and leukemia

Recent work uncovers a role of mutant FLT3-driven Krebs cycle enzyme SUCLG1 in AML, derepressing mitochondrial gene expression and mass.

Metabolic dependencies of acute myeloid leukemia stem cells

Acute myeloid leukemia (AML) is a heterogeneous hematologic malignancy primarily driven by an immature population of AML cells termed leukemia stem cells (LSCs) that are implicated in AML development, chemoresistance, and relapse. An emerging area of research in AML focuses on identifying and targeting the aberrant metabolism in LSCs. Dysregulated metabolism is involved in sustaining functional properties of LSCs, impeding myeloid differentiation, and evading programmed cell death, both in the process of leukemogenesis and in response to chemotherapy. This review discusses recent discoveries regarding the aberrant metabolic processes of AML LSCs that have begun to change the therapeutic landscape of AML.

FLT3-ITD regulation of the endoplasmic reticulum functions in acute myeloid leukemia

The FLT3-ITD mutation represents the most frequent genetic alteration in newly diagnosed acute myeloid leukemia (AML) patient and is associated with poor prognosis. Mutation result in the retention of a constitutively active form of this receptor in the endoplasmic reticulum (ER) and the subsequent modification of its downstream effectors. Here, we assessed the impact of such retention on ER homeostasis and found that mutant cells present lower levels of ER stress due to the overexpression of ERO1α, one of the main proteins of the protein folding machinery at the ER. Overexpression of ERO1α resulted essential for ITD mutant cells survival and chemoresistance and also played a crucial role in shaping the type of glucose metabolism in AML cells, being the mitochondrial pathway the predominant one in those with a higher ER stress (non-mutated cells) and the glycolytic pathway the predominant one in those with lower ER stress (mutated cells). Our data indicate that FLT3 mutational status dictates the route for glucose metabolism in an ERO1α depending on manner and this provides a survival advantage to tumors carrying these ITD mutations.

Metabolic instruction of the graft-versus-leukemia immunity

Allogeneic hematopoietic cell transplantation (allo-HCT) is frequently performed to cure hematological malignancies, such as acute myeloid leukemia (AML), through the graft-versus-leukemia (GVL) effect. In this immunological process, donor immune cells eliminate residual cancer cells in the patient and exert tumor control through immunosurveillance. However, GVL failure and subsequent leukemia relapse are frequent and associated with a dismal prognosis. A better understanding of the mechanisms underlying AML immune evasion is essential for developing novel therapeutic strategies to boost the GVL effect. Cellular metabolism has emerged as an essential regulator of survival and cell fate for both cancer and immune cells. Leukemia and T cells utilize specific metabolic programs, including the orchestrated use of glucose, amino acids, and fatty acids, to support their growth and function. Besides regulating cell-intrinsic processes, metabolism shapes the extracellular environment and plays an important role in cell-cell communication. This review focuses on recent advances in the understanding of how metabolism might affect the anti-leukemia immune response. First, we provide a general overview of the mechanisms of immune escape after allo-HCT and an introduction to leukemia and T cell metabolism. Further, we discuss how leukemia and myeloid cell metabolism contribute to an altered microenvironment that impairs T cell function. Next, we review the literature linking metabolic processes in AML cells with their inhibitory checkpoint ligand expression. Finally, we focus on recent findings concerning the role of systemic metabolism in sustained GVL efficacy. While the majority of evidence in the field still stems from basic and preclinical studies, we discuss translational findings and propose further avenues for bridging the gap between bench and bedside.

Crosstalk between autophagy and metabolism: implications for cell survival in acute myeloid leukemia

Acute myeloid leukemia (AML), a prevalent form of leukemia in adults, is often characterized by low response rates to chemotherapy, high recurrence rates, and unfavorable prognosis. A critical barrier in managing refractory or recurrent AML is the resistance to chemotherapy. Increasing evidence indicates that tumor cell metabolism plays a crucial role in AML progression, survival, metastasis, and treatment resistance. Autophagy, an essential regulator of cellular energy metabolism, is increasingly recognized for its role in the metabolic reprogramming of AML. Autophagy sustains leukemia cells during chemotherapy by not only providing energy but also facilitating rapid proliferation through the supply of essential components such as amino acids and nucleotides. Conversely, the metabolic state of AML cells can influence the activity of autophagy. Their mutual coordination helps maintain intrinsic cellular homeostasis, which is a significant contributor to chemotherapy resistance in leukemia cells. This review explores the recent advancements in understanding the interaction between autophagy and metabolism in AML cells, emphasizing their roles in cell survival and drug resistance. A comprehensive understanding of the interplay between autophagy and leukemia cell metabolism can shed light on leukemia cell survival strategies, particularly under adverse conditions such as chemotherapy. This insight may also pave the way for innovative targeted treatment strategies.

The Potential Transcriptomic and Metabolomic Mechanisms of ATO and ATRA in Treatment of FLT3-ITD Acute Myeloid Leukemia

BACKGROUND

Acute myeloid leukemia (AML) with Fms-like tyrosine kinase 3 gene internal tandem duplication (FLT3-ITD) mutations has a poor prognosis. The combination of arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) has a synergistic killing effect on leukemia cells with FLT3-ITD mutation. However, the mechanism, especially the changes of gene expression and metabolic activity remain unclear. Here we explore the transcriptome and metabolomics changes of FLT3-ITD AML cells treated with ATO/ATRA.

METHODS

RNA-seq was used to identify differential expressed genes (DEGs), and ultra-high performance liquid chromatography-quadrupole electrostatic field orbital trap mass spectrometry (UHPLC-QE-MS) nontargeted metabolomics method was used to screen out the differential metabolites in FLT3-ITD mutant cell lines treated with ATRA and ATO. KEGG pathway database was utilized for pathway exploration and Seahorse XF24 was used to detect extracellular acidification rate (ECAR). Metabolic polymerase chain reaction (PCR) array and real-time quantitative PCR (RT-qPCR) were used to detect mRNA levels of key metabolic genes of glycolysis and fatty acid after drug treatment.

RESULTS

A total of 3873 DEGs were identified and enriched in 281 Gene Ontology (GO) terms, among which 210 were related to biological processes, 43 were related to cellular components, and 28 were related to molecular functions. Besides, 1794 and 927 differential metabolites were screened in positive and negative ion mode separately, and 59 different metabolic pathways were involved, including alanine-aspartate-glutamate metabolic pathway, arginine, and proline metabolic pathway, glycerophospholipid metabolic pathways, etc. According to KEGG Pathway analysis of transcriptome combined with metabolome, glycolysis/gluconeogenesis pathway and fatty acid metabolism pathway were significantly founded enriched. ATRA + ATO may inhibit the glycolysis of FLT3-ITD AML cells by inhibiting FLT3 and its downstream AKT/HK2-VDAC1 signaling pathway.

CONCLUSIONS

The gene transcription profile and metabolites of FLT3-ITD mutant cells changes significantly after treatment, which might be related to the anti-FLT3-ITD AML effect. The screened DEGs, differential metabolites pathway are helpful in studying the mechanism of anti-leukemia effects and drug targets.

Targeting nucleolin improves sensitivity to chemotherapy in acute lymphoblastic leukemia

PURPOSE

Most patients with acute lymphoblastic leukemia (ALL) are treated with chemotherapy as primary care. Although the treatment response is usually positive, resistance and relapse often occur via unknown mechanisms. The purpose of this study was to identify factors associated with chemotherapy resistance in ALL. Here, we present clinical and experimental evidence that overexpression of nucleolin (NCL), a multifunctional nucleolar protein, is linked to drug resistance in ALL.

METHODS

NCL mRNA and protein levels were compared between cell lines and patient samples using qRT-PCR and immunoblotting. NCL mRNA levels were compared between patients of different disease stages from our clinic patients' specimens and publicly available ALL patient datasets. Cells and patient-derived xenograft mouse experiments were performed to assess the effect of NCL inhibition on ALL chemotherapy effectiveness.

RESULTS

Analysis of patient specimens, and publicly available RNA-sequencing datasets revealed a strong correlation between the abundance of NCL and disease relapse or poor survival in B-ALL. Altering NCL expression results in changes in drug sensitivity in ALL cell lines. High levels of NCL upregulated components of the ATP-binding cassette transporters via activation of the ERK pathway, resulting in a decrease in drug accumulation inside the cells. Targeting NCL with AS1411, an NCL-binding oligonucleotide aptamer, significantly increased the sensitivity of ALL cell lines and cells/patient-derived ALL xenograft mice to chemotherapeutic drugs and prolonged mouse survival.

CONCLUSION

Our results highlight NCL as a prognostic marker in B-ALL and a potential therapeutic target to combat chemotherapy resistance in ALL.

PDP1 is a key metabolic gatekeeper and modulator of drug resistance in FLT3-ITD-positive acute myeloid leukemia

High metabolic flexibility is pivotal for the persistence and therapy resistance of acute myeloid leukemia (AML). In 20-30% of AML patients, activating mutations of FLT3, specifically FLT3-ITD, are key therapeutic targets. Here, we investigated the influence of FLT3-ITD on AML metabolism. Nuclear Magnetic Resonance (NMR) profiling showed enhanced reshuffling of pyruvate towards the tricarboxylic acid (TCA) cycle, suggesting an increased activity of the pyruvate dehydrogenase complex (PDC). Consistently, FLT3-ITD-positive cells expressed high levels of PDP1, an activator of the PDC. Combining endogenous tagging of PDP1 with genome-wide CRISPR screens revealed that FLT3-ITD induces PDP1 expression through the RAS signaling axis. PDP1 knockdown resulted in reduced cellular respiration thereby impairing the proliferation of only FLT3-ITD cells. These cells continued to depend on PDP1, even in hypoxic conditions, and unlike FLT3-ITD-negative cells, they exhibited a rapid, PDP1-dependent revival of their respiratory capacity during reoxygenation. Moreover, we show that PDP1 modifies the response to FLT3 inhibition. Upon incubation with the FLT3 tyrosine kinase inhibitor quizartinib (AC220), PDP1 persisted or was upregulated, resulting in a further shift of glucose/pyruvate metabolism towards the TCA cycle. Overexpression of PDP1 enhanced, while PDP1 depletion diminished AC220 resistance in cell lines and peripheral blasts from an AC220-resistant AML patient in vivo. In conclusion, FLT3-ITD assures the expression of PDP1, a pivotal metabolic regulator that enhances oxidative glucose metabolism and drug resistance. Hence, PDP1 emerges as a potentially targetable vulnerability in the management of AML.

TIM-3/Gal-9 interaction affects glucose and lipid metabolism in acute myeloid leukemia cell lines

Introduction

T-cell immunoglobulin and mucin domain-3 (TIM-3) is a transmembrane molecule first identified as an immunoregulator. This molecule is also expressed on leukemic cells in acute myeloid leukemia and master cell survival and proliferation. In this study, we aimed to explore the effect of TIM-3 interaction with its ligand galectin-9 (Gal-9) on glucose and lipid metabolism in AML cell lines.

Methods

HL-60 and THP-1 cell lines, representing M3 and M5 AML subtypes, respectively, were cultured under appropriate conditions. The expression of TIM-3 on the cell surface was ascertained by flow cytometric assay. We used real-time PCR to examine the mRNA expression of GLUT-1, HK-2, PFKFB-3, G6PD, ACC-1, ATGL, and CPT-1A; colorimetric assays to measure the concentration of glucose, lactate, GSH, and the enzymatic activity of G6PD; MTT assay to determine cellular proliferation; and gas chromatography-mass spectrometry (GC-MS) to designate FFAs.

Results

We observed the significant upregulated expression of GLUT-1, HK-2, PFKFB-3, ACC-1, CPT-1A, and G6PD and the enzymatic activity of G6PD in a time-dependent manner in the presence of Gal-9 compared to the PMA and control groups in both HL-60 and THP-1 cell lines (p > 0.05). Moreover, the elevation of extracellular free fatty acids, glucose consumption, lactate release, the concentration of cellular glutathione (GSH) and cell proliferation were significantly higher in the presence of Gal-9 compared to the PMA and control groups in both cell lines (p < 0.05).

Conclusion

TIM-3/Gal-9 ligation on AML cell lines results in aerobic glycolysis and altered lipid metabolism and also protects cells from oxidative stress, all in favor of leukemic cell survival and proliferation.

The role of bone marrow microenvironment (BMM) cells in acute myeloid leukemia (AML) progression: immune checkpoints, metabolic checkpoints, and signaling pathways

Acute myeloid leukemia (AML) comprises a multifarious and heterogeneous array of illnesses characterized by the anomalous proliferation of myeloid cells in the bone marrow microenvironment (BMM). The BMM plays a pivotal role in promoting AML progression, angiogenesis, and metastasis. The immune checkpoints (ICs) and metabolic processes are the key players in this process. In this review, we delineate the metabolic and immune checkpoint characteristics of the AML BMM, with a focus on the roles of BMM cells e.g. tumor-associated macrophages, natural killer cells, dendritic cells, metabolic profiles and related signaling pathways. We also discuss the signaling pathways stimulated in AML cells by BMM factors that lead to AML progression. We then delve into the roles of immune checkpoints in AML angiogenesis, metastasis, and cell proliferation, including co-stimulatory and inhibitory ICs. Lastly, we discuss the potential therapeutic approaches and future directions for AML treatment, emphasizing the potential of targeting metabolic and immune checkpoints in AML BMM as prognostic and therapeutic targets. In conclusion, the modulation of these processes through the use of directed drugs opens up new promising avenues in combating AML. Thereby, a comprehensive elucidation of the significance of these AML BMM cells' metabolic and immune checkpoints and signaling pathways on leukemic cells can be undertaken in the future investigations. Additionally, these checkpoints and cells should be considered plausible multi-targeted therapies for AML in combination with other conventional treatments in AML. Video Abstract.

Petiveria alliacea Reduces Tumor Burden and Metastasis and Regulates the Peripheral Immune Response in a Murine Myeloid Leukemia Model

The poor response, adverse effects and drug resistance to treatment of acute myeloid leukemia (AML) have led to searching for safer and more effective therapeutic alternatives. We previously demonstrated that the alcoholic extract of Petiveria alliacea (Esperanza) has a significant in vitro antitumor effect on other tumor cells and also the ability to regulate energy metabolism. We evaluated the effect of the Esperanza extract in vitro and in vivo in a murine model of AML with DA-3/ER-GM cells. First, a chemical characterization of the extract was conducted through liquid and gas chromatography coupled with mass spectrometry. In vitro findings showed that the extract modulates tumor metabolism by decreasing glucose uptake and increasing reactive oxygen species, which leads to a reduction in cell proliferation. Then, to evaluate the effect of the extract in vivo, we standardized the mouse model by injecting DA-3/ER-GM cells intravenously. The animals treated with the extract showed a lower percentage of circulating blasts, higher values of hemoglobin, hematocrit, and platelets, less infiltration of blasts in the spleen, and greater production of cytokines compared to the control group. These results suggest that the antitumor activity of this extract on DA-3/ER-GM cells can be attributed to the decrease in glycolytic metabolism, its activity as a mitocan, and the possible immunomodulatory effect by reducing tumor proliferation and metastasis.

C/EBPα Confers Dependence to Fatty Acid Anabolic Pathways and Vulnerability to Lipid Oxidative Stress-Induced Ferroptosis in FLT3-Mutant Leukemia

Although transcription factor CCAAT-enhancer binding protein α (C/EBPα) is critical for normal and leukemic differentiation, its role in cell and metabolic homeostasis is largely unknown in cancer. Here, multiomics analyses uncovered a coordinated activation of C/EBPα and Fms-like tyrosine kinase 3 (FLT3) that increased lipid anabolism in vivo and in patients with FLT3-mutant acute myeloid leukemia (AML). Mechanistically, C/EBPα regulated the fatty acid synthase (FASN)-stearoyl-CoA desaturase (SCD) axis to promote fatty acid (FA) biosynthesis and desaturation. We further demonstrated that FLT3 or C/EBPα inactivation decreased monounsaturated FA incorporation to membrane phospholipids through SCD downregulation. Consequently, SCD inhibition enhanced susceptibility to lipid redox stress that was exploited by combining FLT3 and glutathione peroxidase 4 inhibition to trigger lipid oxidative stress, enhancing ferroptotic death of FLT3-mutant AML cells. Altogether, our study reveals a C/EBPα function in lipid homeostasis and adaptation to redox stress, and a previously unreported vulnerability of FLT3-mutant AML to ferroptosis with promising therapeutic application.

SIGNIFICANCE

FLT3 mutations are found in 30% of AML cases and are actionable by tyrosine kinase inhibitors. Here, we discovered that C/EBPα regulates FA biosynthesis and protection from lipid redox stress downstream mutant-FLT3 signaling, which confers a vulnerability to ferroptosis upon FLT3 inhibition with therapeutic potential in AML. This article is highlighted in the In This Issue feature, p. 1501.

NADPH oxidase mediated oxidative stress signaling in FLT3-ITD acute myeloid leukemia

The internal tandem duplication of the juxtamembrane domain of the FMS-like tyrosine kinase 3 (FLT3-ITD) is the most common genetic change in acute myeloid leukemia (AML), and about 30% of all AMLs harbor a FLT3-ITD mutation. Even though FLT3 inhibitors have displayed encouraging effects in FLT3-ITD-mutated AML, the extent of the clinical response to these compounds is cut short due to the rapid development of drug resistance. Evidence has shown that FLT3-ITD triggered activation of oxidative stress signaling may exert a pivotal role in drug resistance. The downstream pathways of FLT3-ITD, including STAT5, PI3K/AKT, and RAS/MAPK, are considered to be major oxidative stress signaling pathways. These downstream pathways can inhibit apoptosis and promote proliferation and survival by regulating apoptosis-related genes and promoting the generation of reactive oxygen species (ROS) through NADPH oxidase (NOX) or other mechanisms. Appropriate levels of ROS may promote proliferation, but high levels of ROS can lead to oxidative damage to the DNA and increase genomic instability. In addition, post-translational modifications of FLT3-ITD and changes in its subcellular localization can affect downstream signaling which may also be one of the mechanisms leading to drug resistance. In this review, we summarized the research progress on NOX mediated oxidative stress signaling and its relationship with drug resistance in FLT3-ITD AML, and discuss the possible new targets in FLT3-ITD signal blocking to reverse drug resistance in FLT3-ITD-mutated AML.

CD147 Facilitates the Pathogenesis of Psoriasis through Glycolysis and H3K9me3 Modification in Keratinocytes

Psoriasis is a chronic inflammatory skin disease featuring rapid proliferation of epidermal cells. Although elevated glycolysis flux has been reported in psoriasis, the molecular mechanisms underlying its pathogenesis remain unclear. We investigated the role of the integral membrane protein CD147 in psoriasis pathogenesis, observing its high expression in psoriatic skin lesions of humans and imiquimod (IMQ)-induced mouse models. In mouse models, genomic deletion of epidermal CD147 markedly attenuated IMQ-induced psoriatic inflammation. We found that CD147 interacted with glucose transporter 1 (Glut1). Depletion of CD147 in the epidermis blocked glucose uptake and glycolysis in vitro and in vivo. In CD147-knockout mice and keratinocytes, oxidative phosphorylation was increased in the epidermis, indicating CD147's pivotal role in glycolysis reprogramming during pathogenesis of psoriasis. Using non-targeted and targeted metabolic techniques, we found that epidermal deletion of CD147 significantly increased the production of carnitine and α-ketoglutaric acid (α-KG). Depletion of CD147 also increased transcriptional expression and activity of γ-butyrobetaine hydroxylase (γ-BBD/BBOX1), a crucial molecule for carnitine metabolism, by inhibiting histone trimethylations of H3K9. Our findings demonstrate that CD147 is critical in metabolic reprogramming through the α-KG-H3K9me3-BBOX1 axis in the pathogenesis of psoriasis, indicating that epidermal CD147 is a promising target for psoriasis treatment.

Advances in Understanding the Links between Metabolism and Autophagy in Acute Myeloid Leukemia: From Biology to Therapeutic Targeting

Autophagy is a highly conserved cellular degradation process that regulates cellular metabolism and homeostasis under normal and pathophysiological conditions. Autophagy and metabolism are linked in the hematopoietic system, playing a fundamental role in the self-renewal, survival, and differentiation of hematopoietic stem and progenitor cells, and in cell death, particularly affecting the cellular fate of the hematopoietic stem cell pool. In leukemia, autophagy sustains leukemic cell growth, contributes to survival of leukemic stem cells and chemotherapy resistance. The high frequency of disease relapse caused by relapse-initiating leukemic cells resistant to therapy occurs in acute myeloid leukemia (AML), and depends on the AML subtypes and treatments used. Targeting autophagy may represent a promising strategy to overcome therapeutic resistance in AML, for which prognosis remains poor. In this review, we illustrate the role of autophagy and the impact of its deregulation on the metabolism of normal and leukemic hematopoietic cells. We report updates on the contribution of autophagy to AML development and relapse, and the latest evidence indicating autophagy-related genes as potential prognostic predictors and drivers of AML. We review the recent advances in autophagy manipulation, combined with various anti-leukemia therapies, for an effective autophagy-targeted therapy for AML.

How ITD Insertion Sites Orchestrate the Biology and Disease of FLT3-ITD-Mutated Acute Myeloid Leukemia

Mutations of the FLT3 gene are among the most common genetic aberrations detected in AML and occur mainly as internal tandem duplications (FLT3-ITD). However, the specific sites of FLT3-ITD insertion within FLT3 show marked heterogeneity regarding both biological and clinical features. In contrast to the common assumption that ITD insertion sites (IS) are restricted to the juxtamembrane domain (JMD) of FLT3, 30% of FLT3-ITD mutations insert at the non-JMD level, thereby integrating into various segments of the tyrosine kinase subdomain 1 (TKD1). ITDs inserted within TKD1 have been shown to be associated with inferior complete remission rates as well as shorter relapse-free and overall survival. Furthermore, resistance to chemotherapy and tyrosine kinase inhibition (TKI) is linked to non-JMD IS. Although FLT3-ITD mutations in general are already recognized as a negative prognostic marker in currently used risk stratification guidelines, the even worse prognostic impact of non-JMD-inserting FLT3-ITD has not yet been particularly considered. Recently, the molecular and biological assessment of TKI resistance highlighted the pivotal role of activated WEE1 kinase in non-JMD-inserting ITDs. Overcoming therapy resistance in non-JMD FLT3-ITD-mutated AML may lead to more effective genotype- and patient-specific treatment approaches.

DNMT3A R882H mutation promotes acute leukemic cell survival by regulating glycolysis through the NRF2/NQO1 axis

BACKGROUND

Studies have confirmed that acute myeloid leukemia (AML) cells with DNA methyltransferase 3A Arg882His (DNMT3A R882H) mutation show an increased proliferation capability. However, the associated mechanism is still unclear. Glycolysis is involved in regulating malignant proliferation of cancer cell. Hence, we analyzed whether the DNMT3A R882H mutation interferes with glycolysis and thereby influences AML cell proliferation.

METHODS

We generated AML cell line carrying a DNMT3A-R882H mutation and compared it with the wild type (DNMT3A-WT) with regard to glycolysis regulation. Moreover, we analyzed the cell line's proliferation and apoptosis by a CCK-8 assay, western blotting, and flow cytometry. The role of NRF2/NQO1 signaling in regulating glycolysis was investigated by NRF2-knockdown and Brusatol (specific inhibitor of NRF2) treatment.

RESULTS

DNMT3A R882H cells had a higher glucose transport capacity compared to WT cells and their viability could be reduced by glucose deprivation. Moreover, daunorubicin had a slight inhibitory effect on glycolysis while glycolysis inhibition re-sensitized mutant cells to daunorubicin. Obviously, DNMT3A R882H mutation activated the NRF2/NQO1 pathway and enhanced the glycolytic activity in mutant cells.

CONCLUSION

Taken together, these results suggest a novel mechanism by which a DNMT3A R882H mutation promotes glycolysis via activation of NRF2/NQO1 pathway. A parallel glycolysis inhibition adds to the anticancer effects of daunorubicin which might lead to a novel therapeutic approach for the treatment of AML patients carrying a DNMT3A R882H mutation.

Epigenomic machinery regulating pediatric AML: clonal expansion mechanisms, therapies, and future perspectives

Acute myeloid leukemia (AML) is a heterogeneous disease with a genetic, epigenetic, and transcriptional etiology mainly presenting somatic and germline abnormalities. AML incidence rises with age but can also occur during childhood. Pediatric AML (pAML) accounts for 15-20% of all pediatric leukemias and differs considerably from adult AML. Next-generation sequencing technologies have enabled the research community to "paint" the genomic and epigenomic landscape in order to identify pathology-associated mutations and other prognostic biomarkers in pAML. Although current treatments have improved the prognosis for pAML, chemoresistance, recurrence, and refractory disease remain major challenges. In particular, pAML relapse is commonly caused by leukemia stem cells that resist therapy. Marked patient-to-patient heterogeneity is likely the primary reason why the same treatment is successful for some patients but, at best, only partially effective for others. Accumulating evidence indicates that patient-specific clonal composition impinges significantly on cellular processes, such as gene regulation and metabolism. Although our understanding of metabolism in pAML is still in its infancy, greater insights into these processes and their (epigenetic) modulation may pave the way toward novel treatment options. In this review, we summarize current knowledge on the function of genetic and epigenetic (mis)regulation in pAML, including metabolic features observed in the disease. Specifically, we describe how (epi)genetic machinery can affect chromatin status during hematopoiesis, leading to an altered metabolic profile, and focus on the potential value of targeting epigenetic abnormalities in precision and combination therapy for pAML. We also discuss the possibility of using alternative epidrug-based therapeutic approaches that are already in clinical practice, either alone as adjuvant treatments and/or in combination with other drugs.

Pacritinib inhibits glucose consumption in squamous cell lung cancer cells by targeting FLT3

Squamous cell lung cancer maintains its growth through elevated glucose consumption, but selective glucose consumption inhibitors are lacking. Here, we discovered using a high-throughput screen new compounds that block glucose consumption in three squamous cell lung cancer cell lines and identified 79 compounds that block glucose consumption in one or more of these cell lines. Based on its ability to block glucose consumption in all three cell lines, pacritinib, an inhibitor of FMS Related Receptor Tyrosine Kinase 3 (FLT3) and Janus Kinase 2 (JAK2), was further studied. Pacritinib decreased glucose consumption in squamous cell lung cancer cells in cell culture and in vivo without affecting glucose consumption in healthy tissues. Pacritinib blocked hexokinase activity, and Hexokinase 1 and 2 mRNA and protein expression. Overexpression of Hexokinase 1 blocked the ability of pacritinib to inhibit glucose consumption in squamous cell lung cancer cells. Overexpression of FLT3 but not JAK2 significantly increased glucose consumption and blocked the ability of pacritinib to inhibit glucose consumption in squamous cell lung cancer cells. Additional FLT3 inhibitors blocked glucose consumption in squamous cell lung cancer cells. Our study identifies FLT3 inhibitors as a new class of inhibitors that can block glucose consumption in squamous cell lung cancer.

GSK3 inhibitor suppresses cell growth and metabolic process in FLT3-ITD leukemia cells

Glycogen Synthase Kinase-3 (GSK-3) was recently implicated in the dysregulated biology of acute myeloid leukemia (AML). Low concentrations of GSK-3 inhibitors, SB216763 and BIO, suppressed the proliferation of AML cells with FLT3-ITD as early as 24 h after treatment. BIO was used in subsequent assays since it exhibited higher inhibitory effects than SB216763. BIO-induced G1 cell cycle arrest by regulating the expression of cyclin D2 and p21 in MV4-11 cells, and promoted apoptosis by regulating the cleaved-caspase3 signaling pathways. In vivo assays demonstrated that BIO suppressed tumor growth, while metabolomics assay showed that BIO reduced the levels of ATP and pyruvate in MV4-11 cells suggesting that it inhibited glycolysis. BIO markedly suppressed cell growth and induced apoptosis of AML cells with FLT3-ITD by partially inhibiting glycolysis, suggesting that BIO may be a promising therapeutic candidate for AML.

Metabolism in Hematopoiesis and Its Malignancy

Hematopoietic stem cells (HSCs) are multipotent stem cells that can self-renew and generate all blood cells of different lineages. The system is under tight control in order to maintain a precise equilibrium of the HSC pool and the effective production of mature blood cells to support various biological activities. Cell metabolism can regulate different molecular activities, such as epigenetic modification and cell cycle regulation, and subsequently affects the function and maintenance of HSC. Upon malignant transformation, oncogenic drivers in malignant hematopoietic cells can remodel the metabolic pathways for supporting the oncogenic growth. The dysregulation of metabolism results in oncogene addiction, implying the development of malignancy-specific metabolism-targeted therapy. In this chapter, we will discuss the significance of different metabolic pathways in hematopoiesis, specifically, the distinctive metabolic dependency in hematopoietic malignancies and potential metabolic therapy.

Circular RNAs: Emerging regulators of glucose metabolism in cancer

Aberrant glucose metabolism is one of the most striking characteristics of metabolic reprogramming in cancer. Thus, clarifying the regulatory mechanism of glucose metabolism is crucial to understanding tumor progression and developing novel therapeutic strategies for cancer patients. Recent developments in circular RNAs have explained the regulatory mechanism of glucose metabolism from a new dimension. In this review, we briefly summarize the recent advances in circRNA research on cancer glucose metabolism and emphasize the different regulatory mechanisms, including acting as miRNA sponges, interacting with proteins and being translated into proteins. Additionally, we discuss the future research directions of circular RNAs in the field of glucose metabolism.

Targeting OXPHOS de novo purine synthesis as the nexus of FLT3 inhibitor-mediated synergistic antileukemic actions

Using a genome-wide CRISPR screen, we identified CDK9, DHODH, and PRMT5 as synthetic lethal partners with gilteritinib treatment in fms-like tyrosine kinase 3 (FLT3)-internal tandem duplication (ITD) acute myeloid leukemia (AML) and genetically and pharmacologically validated their roles in gilteritinib sensitivity. The presence of FLT3-ITD is associated with an increase in anaerobic glycolysis, rendering leukemia cells highly sensitive to inhibition of glycolysis. Supportive of this, our data show the enrichment of single guide RNAs targeting 28 glycolysis-related genes upon gilteritinib treatment, suggesting that switching from glycolysis to oxidative phosphorylation (OXPHOS) may represent a metabolic adaption of AML in gilteritinib resistance. CDK9i/FLT3i, DHODHi/FLT3i, and PRMT5i/FLT3i pairs mechanistically converge on OXPHOS and purine biosynthesis blockade, implying that targeting the metabolic functions of these three genes and/or proteins may represent attractive strategies to sensitize AML to gilteritinib treatment. Our findings provide the basis for maximizing therapeutic impact of FLT3-ITD inhibitors and a rationale for a clinical trial of these novel combinations.

A novel organic arsenic derivative MZ2 remodels metabolism and triggers mtROS-mediated apoptosis in acute myeloid leukemia

PURPOSE

Acute myeloid leukemia (AML) is one of the most common neoplasms in adults, and it is difficult to achieve satisfactory results with conventional drugs. Here, we synthesized a novel organic arsenic derivative MZ2 and evaluated its ability to remodel energy metabolism to achieve anti-leukemia.

METHODS

MZ2 was characterized by the average 1-min full mass spectra analysis. Biological methods such as Western blot, qPCR, flow cytometry and confocal microscopy were used to assess the mode and mechanism of MZ2-induced death. The in vivo efficacy of MZ2 was assessed by constructing a patient-derived xenograft (PDX) AML model.

RESULTS

Unlike the precursor organic arsenical Z2, MZ2 can effectively reduce the level of aerobic glycolysis. Our in-depth found that MZ2 inhibited the expression of PDK2 in a dose-dependent manner and did not affect the expression of LDHA, another key enzyme of the glycolytic pathway. MZ2 reconstituted energy metabolism to induce the generation of mitochondrial ROS (mtROS) and then triggerd intrinsic apoptosis pathway. We also assessed whether MZ2 generates autophagy and results showed that MZ2 can induce autophagy of AML cells, which may be associated with the precursor organic arsenic drug. In vivo, MZ2 effectively attenuated leukemia progression in mice, and immunohistochemical results suggested its PDK2 inhibitory effect.

CONCLUSION

In summary, the novel organic arsine derivative MZ2 exhibited excellent anti-tumor effects in acute myeloid leukemia, which may provide a potential strategy for the treatment of acute myeloid leukemia.

m6A regulator-based methylation modification patterns and characterization of tumor microenvironment in acute myeloid leukemia

RNA N6-methyladenosine (m6A) is the most common and intensively studied RNA modification that critically regulates RNA metabolism, cell signaling, cell survival, and differentiation. However, the overall role of multiple m6A regulators in the tumor microenvironment (TME) has not yet been fully elucidated in acute myeloid leukemia (AML). In our study, we explored the genetic and transcriptional alterations of 23 m6A regulators in AML patients. Three distinct molecular subtypes were identified and associated with prognosis, patient clinicopathological features, as well as TME characteristics. The TME characterization revealed that m6A patterns were highly connected with metabolic pathways such as biosynthesis of unsaturated fatty acids, cysteine and methionine metabolism, and citrate cycle TCA cycle. Then, based on the differentially expressed genes (DEGs) related to m6A molecular subtypes, our study categorized the entire cohort into three m6A gene clusters. Furthermore, we constructed the m6Ascore for quantification of the m6A modification pattern of individual AML patients. It was found that the tumor-infiltrating lymphocyte cells (TILs) closely correlated with the three m6A clusters, three m6A gene clusters, and m6Ascore. And many biological processes were involved, including glycogen degradation, drug metabolism by cytochrome P450, pyruvate metabolism, and so on. Our comprehensive analysis of m6A regulators in AML demonstrated their potential roles in the clinicopathological features, prognosis, tumor microenvironment, and particularly metabolic pathways. These findings may improve our understanding of m6A regulators in AML and offer new perspectives on the assessment of prognosis and the development of anticancer strategy.

Single-Cell Metabolomics in Hematopoiesis and Hematological Malignancies

Aberrant metabolism contributes to tumor initiation, progression, metastasis, and drug resistance. Metabolic dysregulation has emerged as a hallmark of several hematologic malignancies. Decoding the molecular mechanism underlying metabolic rewiring in hematological malignancies would provide promising avenues for novel therapeutic interventions. Single-cell metabolic analysis can directly offer a meaningful readout of the cellular phenotype, allowing us to comprehensively dissect cellular states and access biological information unobtainable from bulk analysis. In this review, we first highlight the unique metabolic properties of hematologic malignancies and underscore potential metabolic vulnerabilities. We then emphasize the emerging single-cell metabolomics techniques, aiming to provide a guide to interrogating metabolism at single-cell resolution. Furthermore, we summarize recent studies demonstrating the power of single-cell metabolomics to uncover the roles of metabolic rewiring in tumor biology, cellular heterogeneity, immunometabolism, and therapeutic resistance. Meanwhile, we describe a practical view of the potential applications of single-cell metabolomics in hematopoiesis and hematological malignancies. Finally, we present the challenges and perspectives of single-cell metabolomics development.

Reactive Oxygen Species and Metabolism in Leukemia: A Dangerous Liaison

Reactive oxygen species (ROS), previously considered toxic by-products of aerobic metabolism, are increasingly recognized as regulators of cellular signaling. Keeping ROS levels low is essential to safeguard the self-renewal capacity of hematopoietic stem cells (HSC). HSC reside in a hypoxic environment and have been shown to be highly dependent on the glycolytic pathway to meet their energy requirements. However, when the differentiation machinery is activated, there is an essential enhancement of ROS together with a metabolic shift toward oxidative metabolism. Initiating and sustaining leukemia depend on the activity of leukemic stem cells (LSC). LSC also show low ROS levels, but unlike HSC, LSC rely on oxygen to meet their metabolic energetic requirements through mitochondrial respiration. In contrast, leukemic blasts show high ROS levels and great metabolic plasticity, both of which seem to sustain their invasiveness. Oxidative stress and metabolism rewiring are recognized as hallmarks of cancer that are intimately intermingled. Here we present a detailed overview of these two features, sustained at different levels, that support a two-way relationship in leukemia. Modifying ROS levels and targeting metabolism are interesting therapeutic approaches. Therefore, we provide the most recent evidence on the modulation of oxidative stress and metabolism as a suitable anti-leukemic approach.

A Resource to Infer Molecular Paths Linking Cancer Mutations to Perturbation of Cell Metabolism

Some inherited or somatically-acquired gene variants are observed significantly more frequently in the genome of cancer cells. Although many of these cannot be confidently classified as driver mutations, they may contribute to shaping a cell environment that favours cancer onset and development. Understanding how these gene variants causally affect cancer phenotypes may help developing strategies for reverting the disease phenotype. Here we focus on variants of genes whose products have the potential to modulate metabolism to support uncontrolled cell growth. Over recent months our team of expert curators has undertaken an effort to annotate in the database SIGNOR 1) metabolic pathways that are deregulated in cancer and 2) interactions connecting oncogenes and tumour suppressors to metabolic enzymes. In addition, we refined a recently developed graph analysis tool that permits users to infer causal paths leading from any human gene to modulation of metabolic pathways. The tool grounds on a human signed and directed network that connects ∼8400 biological entities such as proteins and protein complexes via causal relationships. The network, which is based on more than 30,000 published causal links, can be downloaded from the SIGNOR website. In addition, as SIGNOR stores information on drugs or other chemicals targeting the activity of many of the genes in the network, the identification of likely functional paths offers a rational framework for exploring new therapeutic strategies that revert the disease phenotype.

Modulation of energy metabolism to overcome drug resistance in chronic myeloid leukemia cells through induction of autophagy

Tyrosine kinase inhibitors (TKIs) such as imatinib (IM) are key drugs for treatment of chronic myeloid leukemia (CML). Development of drug resistance to TKIs due to BCR-ABL mutation, especially T315I mutation, poses a major challenge in the clinical treatment of CML. The purpose of this study was to test metabolic modulation as a potential strategy to overcome imatinib resistance based on the possible crosstalk between BCR-ABL signaling and metabolic changes in CML. 2-deoxy-d-glucose (2-DG) was used to modulate the glucose metabolism in CML cells sensitive to IM (KBM5 cell line) and resistant to imatinib with BCR-ABL T315I mutation (KBM5-T315I cell line). Seahorse XFe24 extracellular flux analyzer to quantify oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) was used to measure cellular energy metabolism. Cell proliferation was analyzed by CCK-8 assay and MTS assay. Annexin V/PI staining was used to evaluate cell apoptosis. Autophagy-related proteins and enzyme/proteins were detected by Western blotting. Cellular ATP concentration was detected using an ATP-based Cell Titer Kit. The combined action of 2-DG and IM was evaluated by calculating the drug combination index. Our results found that inhibition of glucose metabolism by 2-DG significantly impaired the viability of CML cells and co-treatment with 2-DG and imatinib induced a synergistic inhibition of KBM5 and KBM5-T315I cells. 2-DG induced cell death by autophagy, not by apoptosis, as evidenced by increased expression of Beclin1 and LC3AII and lack of annexin V/PI-positive cells. At the biochemical level, 2-DG inhibited glycolysis and mitochondrial oxygen consumption manifested by a significant decrease in ECAR and OCR, and a depletion of ATP. The severe metabolic stress induced by 2-DG in CML cells led to autophagic cell death. Our results suggested a metabolic vulnerability of CML cells that could be targeted by a combination of 2-DG and imatinib as an alternative treatment for imatinib-resistant CML.

Mechanisms of Resistance to Targeted Therapies for Relapsed or Refractory Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is an aggressive disease of clonal hematopoiesis with a high rate of relapse and refractory disease despite intensive therapy. Traditionally, relapsed or refractory AML has increased therapeutic resistance and poor long-term survival. In recent years, advancements in the mechanistic understanding of leukemogenesis have allowed for the development of targeted therapies. These therapies offer novel alternatives to intensive chemotherapy and have prolonged survival in relapsed or refractory AML. Unfortunately, a significant portion of patients do not respond to these therapies and relapse occurs in most patients who initially responded. This review focuses on the mechanisms of resistance to targeted therapies in relapsed or refractory AML.

Pharmacologic Reduction of Mitochondrial Iron Triggers a Noncanonical BAX/BAK-Dependent Cell Death

Cancer cell metabolism is increasingly recognized as providing an exciting therapeutic opportunity. However, a drug that directly couples targeting of a metabolic dependency with the induction of cell death in cancer cells has largely remained elusive. Here we report that the drug-like small-molecule ironomycin reduces the mitochondrial iron load, resulting in the potent disruption of mitochondrial metabolism. Ironomycin promotes the recruitment and activation of BAX/BAK, but the resulting mitochondrial outer membrane permeabilization (MOMP) does not lead to potent activation of the apoptotic caspases, nor is the ensuing cell death prevented by inhibiting the previously established pathways of programmed cell death. Consistent with the fact that ironomycin and BH3 mimetics induce MOMP through independent nonredundant pathways, we find that ironomycin exhibits marked in vitro and in vivo synergy with venetoclax and overcomes venetoclax resistance in primary patient samples.

SIGNIFICANCE

Ironomycin couples targeting of cellular metabolism with cell death by reducing mitochondrial iron, resulting in the alteration of mitochondrial metabolism and the activation of BAX/BAK. Ironomycin induces MOMP through a different mechanism to BH3 mimetics, and consequently combination therapy has marked synergy in cancers such as acute myeloid leukemia. This article is highlighted in the In This Issue feature, p. 587.

Identification of the Benzoimidazole Compound as a Selective FLT3 Inhibitor by Cell-Based High-Throughput Screening of a Diversity Library

Internal tandem duplication in the FLT3 receptor tyrosine kinase (FLT3/ITD mutation) occurs in approximately 25% of acute myeloid leukemia (AML) patients. To specifically target this driver mutation in AML, we assessed and compared the cell-based cytotoxicity of a diversity library (10,000 compounds) against the normal cell line BaF3 and the isogenic leukemic cell line BaF3/ITD. A benzoimidazole scaffold-based compound (HP1142) was identified as the most selective compound against a series of murine and human leukemia cells with FLT3/ITD. Novel benzoimidazole compounds were further designed to improve the aqueous solubility of HP1142. The most potent compound, HP1328, demonstrated desirable pharmaceutical and pharmacokinetic properties. Treatment with HP1328 significantly reduced the leukemia burden and prolonged the survival of mice with FLT3/ITD leukemia. Our findings establish the specific activity of the benzoimidazole compound against FLT3/ITD leukemia and warrant further investigation in this subset of leukemia patients with poor prognosis.

Translatome changes in acute myeloid leukemia cells post-exposure to pegcrisantaspase and venetoclax

The clinical outcomes of patients with AML treated with available therapy remains unsatisfactory. We recently reported that the BCL-2 inhibitor, venetoclax, synergized with pegcrisantaspase (PegC) and demonstrated remarkable in vivo efficacy in a preclinical model of AML with complex karyotype. Ven-PegC combination blocks synthesis of proteins in AML cells by inhibiting cap-dependent translation of mRNA. To further explore the impact of Ven-PegC on protein translation, we used polysome profiling and high-throughput RNA-seq to characterize Ven-PegC dependent changes to the translatome. Here we report that the translation of five mRNAs, including two microRNAs, one rRNA, and two mitochondrial genes was altered after exposure to all three treatments (Ven, PegC and Ven-PegC). We focused our translatome validation studies on six additional genes related to translational efficiency that were modified by Ven-PegC. Notably, Ven-PegC treatment increased the RNA translation and protein level of Tribbles homolog 3 (TRIB3), eukaryotic translation initiation factor 3 subunit C (eIF3C), doublesex and mab-3 related transcription factor 1 (DMRT1), salt inducible kinase 1 (SIK1). We validated the observed changes in gene/protein expression in vitro and confirmed our cell line-based studies in the bone marrow of an AML PDX model after Ven-PegC treatment. These results support examining alterations in the translatome post-chemotherapy to offer insight into drug mechanism of action and to inform future therapeutic decisions.

The Importance of Cellular Metabolic Pathways in Pathogenesis and Selective Treatments of Hematological Malignancies

Despite recent advancements in the treatment of hematologic malignancies and the emergence of newer and more sophisticated therapeutic approaches such as immunotherapy, long-term overall survival remains unsatisfactory. Metabolic alteration, as an important hallmark of cancer cells, not only contributes to the malignant transformation of cells, but also promotes tumor progression and metastasis. As an immune-escape mechanism, the metabolic adaptation of the bone marrow microenvironment and leukemic cells is a major player in the suppression of anti-leukemia immune responses. Therefore, metabolic rewiring in leukemia would provide promising opportunities for newer therapeutic interventions. Several therapeutic agents which affect essential bioenergetic pathways in cancer cells including glycolysis, β-oxidation of fatty acids and Krebs cycle, or anabolic pathways such as lipid biosynthesis and pentose phosphate pathway, are being tested in various types of cancers. So far, numerous preclinical or clinical trial studies using such metabolic agents alone or in combination with other remedies such as immunotherapy are in progress and have demonstrated promising outcomes. In this review, we aim to argue the importance of metabolic alterations and bioenergetic pathways in different types of leukemia and their vital roles in disease development. Designing treatments based on targeting leukemic cells vulnerabilities, particularly in nonresponsive leukemia patients, should be warranted.

The glutaminase inhibitor telaglenastat enhances the antitumor activity of signal transduction inhibitors everolimus and cabozantinib in models of renal cell carcinoma

Dysregulated metabolism is a hallmark of cancer that manifests through alterations in bioenergetic and biosynthetic pathways to enable tumor cell proliferation and survival. Tumor cells exhibit high rates of glycolysis, a phenomenon known as the Warburg effect, and an increase in glutamine consumption to support the tricarboxylic acid (TCA) cycle. Renal cell carcinoma (RCC) tumors express high levels of glutaminase (GLS), the enzyme required for the first step in metabolic conversion of glutamine to glutamate and the entry of glutamine into the TCA cycle. We found that RCC cells are highly dependent on glutamine for proliferation, and this dependence strongly correlated with sensitivity to telaglenstat (CB-839), an investigational, first-in-class, selective, orally bioavailable GLS inhibitor. Metabolic profiling of RCC cell lines treated with telaglenastat revealed a decrease in glutamine consumption, which was concomitant with a decrease in the production of glutamate and other glutamine-derived metabolites, consistent with GLS inhibition. Treatment of RCC cells with signal transduction inhibitors everolimus (mTOR inhibitor) or cabozantinib (VEGFR/MET/AXL inhibitor) in combination with telaglenastat resulted in decreased consumption of both glucose and glutamine and synergistic anti-proliferative effects. Treatment of mice bearing Caki-1 RCC xenograft tumors with cabozantinib plus telaglenastat resulted in reduced tumor growth compared to either agent alone. Enhanced anti-tumor activity was also observed with the combination of everolimus plus telaglenastat. Collectively, our results demonstrate potent, synergistic, anti-tumor activity of telaglenastat plus signal transduction inhibitors cabozantinib or everolimus via a mechanism involving dual inhibition of glucose and glutamine consumption.

One Omics Approach Does Not Rule Them All: The Metabolome and the Epigenome Join Forces in Haematological Malignancies

Aberrant DNA methylation, dysregulation of chromatin-modifying enzymes, and microRNAs (miRNAs) play a crucial role in haematological malignancies. These epimutations, with an impact on chromatin accessibility and transcriptional output, are often associated with genomic instability and the emergence of drug resistance, disease progression, and poor survival. In order to exert their functions, epigenetic enzymes utilize cellular metabolites as co-factors and are highly dependent on their availability. By affecting the expression of metabolic enzymes, epigenetic modifiers may aid the generation of metabolite signatures that could be utilized as targets and biomarkers in cancer. This interdependency remains often neglected and poorly represented in studies, despite well-established methods to study the cellular metabolome. This review critically summarizes the current knowledge in the field to provide an integral picture of the interplay between epigenomic alterations and the cellular metabolome in haematological malignancies. Our recent findings defining a distinct metabolic signature upon response to enhancer of zeste homolog 2 (EZH2) inhibition in multiple myeloma (MM) highlight how a shift of preferred metabolic pathways may potentiate novel treatments. The suggested link between the epigenome and the metabolome in haematopoietic tumours holds promise for the use of metabolic signatures as possible biomarkers of response to treatment.

Integrated genomic-metabolic classification of acute myeloid leukemia defines a subgroup with NPM1 and cohesin/DNA damage mutations

Although targeting of cell metabolism is a promising therapeutic strategy in acute myeloid leukemia (AML), metabolic dependencies are largely unexplored. We aimed to classify AML patients based on their metabolic landscape and map connections between metabolic and genomic profiles. Combined serum and urine metabolomics improved AML characterization compared with individual biofluid analysis. At intracellular level, AML displayed dysregulated amino acid, nucleotide, lipid, and bioenergetic metabolism. The integration of intracellular and biofluid metabolomics provided a map of alterations in the metabolism of polyamine, purine, keton bodies and polyunsaturated fatty acids and tricarboxylic acid cycle. The intracellular metabolome distinguished three AML clusters, correlating with distinct genomic profiles: NPM1-mutated(mut), chromatin/spliceosome-mut and TP53-mut/aneuploid AML that were confirmed by biofluid analysis. Interestingly, integrated genomic-metabolic profiles defined two subgroups of NPM1-mut AML. One was enriched for mutations in cohesin/DNA damage-related genes (NPM1/cohesin-mut AML) and showed increased serum choline + trimethylamine-N-oxide and leucine, higher mutation load, transcriptomic signatures of reduced inflammatory status and better ex-vivo response to EGFR and MET inhibition. The transcriptional differences of enzyme-encoding genes between NPM1/cohesin-mut and NPM1-mut allowed in silico modeling of intracellular metabolic perturbations. This approach predicted alterations in NAD and purine metabolism in NPM1/cohesin-mut AML that suggest potential vulnerabilities, worthy of being therapeutically explored.

Insights into the molecular profiles of adult and paediatric acute myeloid leukaemia

Acute myeloid leukaemia (AML) is a clinically and molecularly heterogeneous disease characterised by uncontrolled proliferation, block in differentiation and acquired self-renewal of hematopoietic stem and myeloid progenitor cells. This results in the clonal expansion of myeloid blasts within the bone marrow and peripheral blood. The incidence of AML increases with age, and in childhood, AML accounts for 20% of all leukaemias. Whilst there are many clinical and biological similarities between paediatric and adult AML with continuum across the age range, many characteristics of AML are associated with age of disease onset. These include chromosomal aberrations, gene mutations and differentiation lineage. Following chemotherapy, AML cells that survive and result in disease relapse exist in an altered chemoresistant state. Molecular profiling currently represents a powerful avenue of experimentation to study AML cells from adults and children pre- and postchemotherapy as a means of identifying prognostic biomarkers and targetable molecular vulnerabilities that may be age-specific. This review highlights recent advances in our knowledge of the molecular profiles with a focus on transcriptomes and metabolomes, leukaemia stem cells and chemoresistant cells in adult and paediatric AML and focus on areas that hold promise for future therapies.

Sorafenib for hepatocellular carcinoma: potential molecular targets and resistance mechanisms

Hepatocellular carcinoma (HCC) is the most widespread typical therapy-resistant, unresectable type of malignant solid tumour with a high death rate constituting huge medical concern. Sorafenib is a small molecule oral multi-target kinase potent inhibitor that acts by suppressing/blocking the multiplication of the tumour cells, angiogenesis, and encouraging apoptosis of the tumour cells. Though, the precise mechanism of tumour cell death induction by sorafenib is yet under exploration. Furthermore, genetic heterogeneity plays a critical role in developing sorafenib resistance, which leads the way to identify the need for predictive biomarkers responsible for drug resistance. Therefore, it is essential to find out the fundamental resistance mechanisms to expand therapeutic plans. The authors summarize the molecular concepts of resistance, progression, potential molecular targets, HCC management therapies, and discussion on the advancements expected in the coming future, inclusive of biomarker-driven treatment strategies, which may provide the prospects to design innovative therapeutically targeted strategies for the HCC treatment and the clinical implementation of emerging targeted agents.

A dual inhibitor overcomes drug-resistant FLT3-ITD acute myeloid leukemia

FLT3 mutations are the most frequently identified genetic alterations in acute myeloid leukemia (AML) and are associated with poor prognosis. Multiple FLT3 inhibitors are in various stages of clinical evaluation. However, resistance to FLT3 inhibitors resulting from acquired point mutations in tyrosine kinase domain (TKD) have limited the sustained efficacy of treatments, and a "gatekeeper" mutation (F691L) is resistant to most available FLT3 inhibitors. Thus, new FLT3 inhibitors against both FLT3 internal tandem duplication (FLT3-ITD) and FLT3-TKD mutations (including F691L) are urgently sought. Herein, we identified KX2-391 as a dual FLT3 and tubulin inhibitor and investigated its efficacy and mechanisms in overcoming drug-resistant FLT3-ITD-TKD mutations in AML. KX2-391 exhibited potent growth inhibitory and apoptosis promoting effects on diverse AML cell lines harboring FLT3-ITD mutations and AC220-resistant mutations at the D835 and F691 residues in TKD and inhibited FLT3 phosphorylation and its downstream signaling targets. Orally administered KX2-391 significantly prolonged the survival of a murine leukemia model induced by FLT3-ITD-F691L. KX2-391 also significantly inhibited the growth of 4 primary AML cells expressing FLT3-ITD and 2 primary AML cells expressing FLT3-ITD-D835Y. Our preclinical data highlight KX2-391 as a promising FLT3 inhibitor for the treatment of AML patients harboring FLT3 mutations, especially refractory/relapsed patients with F691L and other FLT3-TKD mutations.

Anti-Tumor Effects of BDH1 in Acute Myeloid Leukemia

Dysregulation of ketone metabolism has been reported in various types of cancer. In order to find out its role in acute myeloid leukemia (AML) pathogenesis, we first analyzed the expression levels of 10 key genes involved in ketone metabolism in AML blasts and CD34⁺ hematopoietic stem cells (HSCs) from healthy donors. We found that the expression level of BDH1 was significantly lower in AML than in normal HSCs. The downregulation of BDH1 gene expression in AML cell lines as compared with normal HSCs was further confirmed with real-time RT-PCR. Analysis of TCGA and other database revealed that the downregulation of BDH1 was associated with worse prognosis in AML patients. In addition, we showed that overexpression of BDH1 inhibited the viability and proliferation of AML cells. In contrast, BDH1 knock-down promoted AML cell growth. Collectively, our results suggest the previously unappreciated anti-tumor role of BDH1 in AML, and low BDH1 expression predicts poor survival.

Mitochondrial metabolism: powering new directions in acute myeloid leukemia

There has been an explosion of knowledge about the role of metabolism and the mitochondria in acute myeloid leukemia (AML). We have also recently seen several waves of novel therapies change the treatment landscape for AML, such as the selective B-cell lymphoma 2 (BCL-2) inhibitor venetoclax. In this new context, we review the rapidly advancing literature on the role of metabolism and the mitochondria in AML pathogenesis, and how these are interwoven with the mechanisms of action for novel therapeutics in AML. We also review the role of oxidative phosphorylation (OxPhos) in maintaining leukemia stem cells (LSCs), how recurrent genomic alterations in AML alter downstream metabolism, and focus on how the BCL-2 pathway and the mitochondria are inextricably linked in AML. Thus, we provide an overview of the mitochondria and metabolism in the context of our new therapeutic world for AML and outline how targeting these vulnerabilities may produce novel therapeutic strategies.

LSD1 defines erythroleukemia metabolism by controlling the lineage-specific transcription factors GATA1 and C/EBPα

Acute myeloid leukemia (AML) is a heterogenous malignancy characterized by distinct lineage subtypes and various genetic/epigenetic alterations. As with other neoplasms, AML cells have well-known aerobic glycolysis, but metabolic variations depending on cellular lineages also exist. Lysine-specific demethylase-1 (LSD1) has been reported to be crucial for human leukemogenesis, which is currently one of the emerging therapeutic targets. However, metabolic roles of LSD1 and lineage-dependent factors remain to be elucidated in AML cells. Here, we show that LSD1 directs a hematopoietic lineage-specific metabolic program in AML subtypes. Erythroid leukemia (EL) cells particularly showed activated glycolysis and high expression of LSD1 in both AML cell lines and clinical samples. Transcriptome, chromatin immunoprecipitation-sequencing, and metabolomic analyses revealed that LSD1 was essential not only for glycolysis but also for heme synthesis, the most characteristic metabolic pathway of erythroid origin. Notably, LSD1 stabilized the erythroid transcription factor GATA1, which directly enhanced the expression of glycolysis and heme synthesis genes. In contrast, LSD1 epigenetically downregulated the granulo-monocytic transcription factor C/EBPα. Thus, the use of LSD1 knockdown or chemical inhibitor dominated C/EBPα instead of GATA1 in EL cells, resulting in metabolic shifts and growth arrest. Furthermore, GATA1 suppressed the gene encoding C/EBPα that then acted as a repressor of GATA1 target genes. Collectively, we conclude that LSD1 shapes metabolic phenotypes in EL cells by balancing these lineage-specific transcription factors and that LSD1 inhibitors pharmacologically cause lineage-dependent metabolic remodeling.

The Role of Metabolism in the Development of Personalized Therapies in Acute Myeloid Leukemia

Despite significant recent advances in our understanding of the biology and genetics of acute myeloid leukemia (AML), current AML therapies are mostly based on a backbone of standard chemotherapy which has remained mostly unchanged for over 20 years. Several novel therapies, mostly targeting neomorphic/activating recurrent mutations found in AML patients, have only recently been approved following encouraging results, thus providing the first evidence of a more precise and personalized approach to AML therapy. Rewired metabolism has been described as a hallmark of cancer and substantial evidence of its role in AML establishment and maintenance has been recently accrued in preclinical models. Interestingly, unique metabolic changes are generated by specific AML recurrent mutations or in response to diverse AML therapies, thus creating actionable metabolic vulnerabilities in specific patient groups. In this review we will discuss the current evidence supporting a role for rewired metabolism in AML pathogenesis and how these metabolic changes can be leveraged to develop novel personalized therapies.

Mitochondrial metabolism as a target for acute myeloid leukemia treatment

Acute myeloid leukemias (AML) are a group of aggressive hematologic malignancies resulting from acquired genetic mutations in hematopoietic stem cells that affect patients of all ages. Despite decades of research, standard chemotherapy still remains ineffective for some AML subtypes and is often inappropriate for older patients or those with comorbidities. Recently, a number of studies have identified unique mitochondrial alterations that lead to metabolic vulnerabilities in AML cells that may present viable treatment targets. These include mtDNA, dependency on oxidative phosphorylation, mitochondrial metabolism, and pro-survival signaling, as well as reactive oxygen species generation and mitochondrial dynamics. Moreover, some mitochondria-targeting chemotherapeutics and their combinations with other compounds have been FDA-approved for AML treatment. Here, we review recent studies that illuminate the effects of drugs and synergistic drug combinations that target diverse biomolecules and metabolic pathways related to mitochondria and their promise in experimental studies, clinical trials, and existing chemotherapeutic regimens.