Omega-3 Poly-Unsaturated Fatty Acids for the Prevention of Severe Neutropenic Enterocolitis in Patients with Acute Myeloid Leukemia

Background: In Acute Myeloid Leukemia (AML), a complete response to chemotherapy is usually obtained after conventional chemotherapy but overall patient survival is poor due to highly frequent relapses. As opposed to chronic myeloid leukemia, B lymphoma or multiple myeloma, AML is one of the rare malignant hemopathies the therapy of which has not significantly improved during the past 30 years despite intense research efforts. One promising approach is to determine metabolic dependencies in AML cells. Moreover, two key metabolic enzymes, isocitrate dehydrogenases (IDH1/2), are mutated in more than 15% of AML patient, reinforcing the interest in studying metabolic reprogramming, in particular in this subgroup of patients. Methods: Using a multi-omics approach combining proteomics, lipidomics, and isotopic profiling of [U-13C] glucose and [U-13C] glutamine cultures with more classical biochemical analyses, we studied the impact of the IDH1 R132H mutation in AML cells on lipid biosynthesis. Results: Global proteomic and lipidomic approaches showed a dysregulation of lipid metabolism, especially an increase of phosphatidylinositol, sphingolipids (especially few species of ceramide, sphingosine, and sphinganine), free cholesterol and monounsaturated fatty acids in IDH1 mutant cells. Isotopic profiling of fatty acids revealed that higher lipid anabolism in IDH1 mutant cells corroborated with an increase in lipogenesis fluxes. Conclusions: This integrative approach was efficient to gain insight into metabolism and dynamics of lipid species in leukemic cells. Therefore, we have determined that lipid anabolism is strongly reprogrammed in IDH1 mutant AML cells with a crucial dysregulation of fatty acid metabolism and fluxes, both being mediated by 2-HG (2-Hydroxyglutarate) production.

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Mannose Metabolism Is a Metabolic Vulnerability Unveiled By Standard and Novel Therapies in Acute Myeloid Leukemia

Blood ◽

10.1182/blood-2021-148489 ◽

2021 ◽

Vol 138 (Supplement 1) ◽

pp. 508-508

Author(s):

Keith Woodley ◽

Laura S Dillingh ◽

George Giotopoulos ◽

Pedro Madrigal ◽

Konstantinos Tzelepis ◽

...

Keyword(s):

Lipid Peroxidation ◽

Fatty Acids ◽

Cell Death ◽

Acute Myeloid Leukemia ◽

Fatty Acid ◽

Myeloid Leukemia ◽

Novel Therapies ◽

Mannose Metabolism ◽

Acute Myeloid

Abstract Introduction The development of resistance to standard and novel therapies remains the main obstacle to cure in acute myeloid leukemia (AML). Metabolic rewiring has emerged as a therapeutically actionable vulnerability in AML, where specific metabolic adaptations arising as a result of driver mutations or in response to therapy have been reported. Mannose phosphoisomerase (MPI) is the first enzyme in the mannose metabolism (MM) pathway, that leads to the production of GDP-Mannose, a key sugar donor for N-glycosylation reactions. MPI was amongst the top drop-out genes in our published CRISPR-Cas9 screen aiming to identify sensitizers to FLT3 tyrosine kinase inhibitors (TKI) in AML carrying activating FLT3 internal tandem duplication (ITD) mutations (Gallipoli et al., Blood 2018). Moreover, analysis of published genomic datasets indicates that MPI expression levels are higher in AML compared to normal samples, correlate with patient outcome (A) and further increase in paired relapsed to diagnosis samples. We therefore hypothesized that MM and MPI inhibition sensitize AML cells to both FLT3-TKI and standard chemotherapy and tested this in preclinical models. Methods Experiments were performed in human AML cell lines, primary AML mononuclear cells and normal CD34 + stem/progenitor cells. Liquid chromatography coupled to mass spectrometry and oxygen consumption/extracellular acidification rate as measured by a Seahorse analyser were employed to assess metabolic changes. Gene-expression was measured by RNA-sequencing and confirmed by RT-qPCR. Viability, surface protein expression and lipid peroxidation were assessed by flow-cytometry. Protein expression and localisation was measured by western blot and immunofluorescence. Gene silencing was performed using CRISPR-Cas9 gene editing and inducible short hairpin RNA interference. Results We show that genetic and chemical MPI inhibition sensitizes FLT3 WT and FLT3 ITD AML cell lines in vitro to standard cytarabine chemotherapy and FLT3-TKI respectively and these effects are rescued by the addition of MPI downstream product mannose. We validate these findings in vivo using MPI knock-out (KO) cell line xenografts and in vitro using primary AML samples following MPI knock-down (B). We also demonstrate a lack of toxicity to normal CD34 + cells. Surprisingly, global metabolomic analysis show that MPI KO cells accumulate fatty acids and particularly polyunsaturated fatty acids (PUFA) (C), due to both increased uptake and reduced fatty acid oxidation (FAO). MPI KO cells downregulate several FAO metabolism genes and this is corroborated by the strong positive correlation of MPI expression levels with multiple genes involved in FAO across multiple primary AML datasets. Metabolic profiling demonstrates that MPI KO cells have reduced oxidative phosphorylation metabolism and in particular are unable to oxidise palmitate, an effect rescued by mannose or the FAO activator fenofibrate (D). We link this metabolic defect to the specific activation of the ATF6 arm of the unfolded protein response (UPR) due to a reduction in protein glycosylation in MPI KO cells. We validate this by demonstrating that activating or inhibiting ATF6 respectively phenocopies or rescues the effects of MPI KO (E) and show this to be secondary to ATF6 driving FAO inhibition, via transcriptional downregulation of PPARα, a master regulator of lipid catabolism. Finally, we show that accumulation of PUFA in MPI KO cells is accompanied by reduced cysteine levels and increased markers of oxidative stress and lipid peroxidation, such as 4-hydroxynonenal (4-HNE), all features associated with ferroptosis (F). We validate this by showing that combining FLT3-TKI with MPI KO leads to ferroptotic cell death in AML cells, which can be rescued by the radical-trapping antioxidant ferrostatin. Conclusions We provide further evidence to support the role of metabolic rewiring in driving therapy resistance in AML and show for the first time that targeting MPI and MM sensitizes AML cells to cytarabine and FLT3-TKI. Mechanistically we unveil a novel connection between MM and fatty acid metabolism, via activation of the ATF6 arm of the UPR, leading to cellular PUFA accumulation, lipid peroxidation and ferroptotic cell death. Finally, our findings also suggest that triggering ferroptosis can be leveraged as a therapeutically actionable mechanism driving cell death in therapy-resistant AML cells. Figure 1 Figure 1. Disclosures Vassiliou: Kymab Ltd: Divested equity in a private or publicly-traded company in the past 24 months; STRM.BIO: Consultancy; Astrazeneca: Consultancy.

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Discovery of putative tumor suppressors from CRISPR screens reveals rewired lipid metabolism in acute myeloid leukemia cells

Nature Communications ◽

10.1038/s41467-021-26867-8 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

W. Frank Lenoir ◽

Micaela Morgado ◽

Peter C. DeWeirdt ◽

Megan McLaughlin ◽

Audrey L. Griffith ◽

...

Keyword(s):

Fatty Acids ◽

Acute Myeloid Leukemia ◽

Cell Lines ◽

Myeloid Leukemia ◽

Saturated Fatty Acids ◽

Leukemia Cell ◽

Loss Of Function ◽

Suppressor Activity ◽

Acute Myeloid Leukemia Cells ◽

Acute Myeloid

AbstractCRISPR knockout fitness screens in cancer cell lines reveal many genes whose loss of function causes cell death or loss of fitness or, more rarely, the opposite phenotype of faster proliferation. Here we demonstrate a systematic approach to identify these proliferation suppressors, which are highly enriched for tumor suppressor genes, and define a network of 145 such genes in 22 modules. One module contains several elements of the glycerolipid biosynthesis pathway and operates exclusively in a subset of acute myeloid leukemia cell lines. The proliferation suppressor activity of genes involved in the synthesis of saturated fatty acids, coupled with a more severe loss of fitness phenotype for genes in the desaturation pathway, suggests that these cells operate at the limit of their carrying capacity for saturated fatty acids, which we confirm biochemically. Overexpression of this module is associated with a survival advantage in juvenile leukemias, suggesting a clinically relevant subtype.

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Cytomegalovirus-related neutropenic enterocolitis with negative CMV antigenemia as the initial presentation in an acute myeloid leukemia patient

Annals of Hematology ◽

10.1007/s00277-008-0596-3 ◽

2008 ◽

Vol 88 (3) ◽

pp. 279-280 ◽

Cited By ~ 1

Author(s):

Yu-Min Yeh ◽

Ya-Ping Chen ◽

Hung-Chang Wu ◽

Wu-Chou Su ◽

Tsai-Yun Chen

Keyword(s):

Acute Myeloid Leukemia ◽

Myeloid Leukemia ◽

Acute Myeloid Leukemia Patient ◽

Initial Presentation ◽

Neutropenic Enterocolitis ◽

Leukemia Patient ◽

Cmv Antigenemia ◽

Acute Myeloid

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A Role for Lipid Mediators in Acute Myeloid Leukemia

International Journal of Molecular Sciences ◽

10.3390/ijms20102425 ◽

2019 ◽

Vol 20 (10) ◽

pp. 2425 ◽

Cited By ~ 6

Author(s):

Andreas Loew ◽

Thomas Köhnke ◽

Emma Rehbeil ◽

Anne Pietzner ◽

Karsten-H. Weylandt

Keyword(s):

Acute Myeloid Leukemia ◽

Myeloid Leukemia ◽

Immune Therapy ◽

Hematologic Malignancies ◽

Lipid Mediators ◽

Lipid Mediator ◽

Omega 3 ◽

Immune Mechanisms ◽

Acute Myeloid

In spite of therapeutic improvements in the treatment of different hematologic malignancies, the prognosis of acute myeloid leukemia (AML) treated solely with conventional induction and consolidation chemotherapy remains poor, especially in association with high risk chromosomal or molecular aberrations. Recent discoveries describe the complex interaction of immune effector cells, as well as the role of the bone marrow microenvironment in the development, maintenance and progression of AML. Lipids, and in particular omega-3 as well as omega-6 polyunsaturated fatty acids (PUFAs) have been shown to play a vital role as signaling molecules of immune processes in numerous benign and malignant conditions. While the majority of research in cancer has been focused on the role of lipid mediators in solid tumors, some data are showing their involvement also in hematologic malignancies. There is a considerable amount of evidence that AML cells are targetable by innate and adaptive immune mechanisms, paving the way for immune therapy approaches in AML. In this article we review the current data showing the lipid mediator and lipidome patterns in AML and their potential links to immune mechanisms.

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Predictors of Mortality in Neutropenic Enterocolitis Among Children and Young Adults with Acute Myeloid Leukemia

Clinical Lymphoma Myeloma & Leukemia ◽

10.1016/j.clml.2019.07.135 ◽

2019 ◽

Vol 19 ◽

pp. S240

Author(s):

Reham Khedr ◽

Mohamed Abdelwaged ◽

Marwa Fathy ◽

Wael Zekri

Keyword(s):

Acute Myeloid Leukemia ◽

Young Adults ◽

Myeloid Leukemia ◽

Neutropenic Enterocolitis ◽

Predictors Of Mortality ◽

Children And Young Adults ◽

Acute Myeloid

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Autophagy in the Hematopoietic System

Blood ◽

10.1182/blood-2019-121093 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. SCI-44-SCI-44 ◽

Cited By ~ 1

Author(s):

Anna K. Simon ◽

Sandrine Obba ◽

Hanlin Zhang ◽

Thomas Riffelmacher

Keyword(s):

Fatty Acids ◽

Acute Myeloid Leukemia ◽

Free Fatty Acids ◽

Myeloid Leukemia ◽

Building Blocks ◽

Hematopoietic Stem ◽

Hematopoietic System ◽

Neutrophil Differentiation ◽

Acute Myeloid

Autophagy, the major lysosomal degradation pathway in the cell plays a key role in the maintenance of metabolism, healthy mitochondria and limits reactive oxygen species, thus keeping the genome and proteome healthy. We demonstrated that erythroblasts rely on mitophagy as they differentiate into erythrocytes 1 and that hematopoietic stem cells (HSCs) require autophagy to survive and repopulate a new hematopoietic system 2. Genetic ablation of Atg7 in the hematopoietic system, which encodes a component of the autophagy system, resulted in a pre-leukemic phenotype, which predicted low autophagic flux found in blasts from patients with acute myeloid leukemia 3. Most recently, our studies indicate that autophagy provides free fatty acids for neutrophil differentiation by degrading lipid droplets 4. However, it is not clear what is degraded by autophagy in HSCs or whether autophagy is required to provide building blocks to the HSC and what the nature of these building blocks is. We are currently addressing this by using state-of-the-art in vivo techniques, and I will report our findings in my presentation. 1 Mortensen, M., Ferguson, D. J., Edelmann, M., Kessler, B., Morten, K. J., Komatsu, M. & Simon, A. K. Loss of autophagy in erythroid cells leads to defective removal of mitochondria and severe anemia in vivo. Proc Natl Acad Sci U S A 107, 832-837, doi:10.1073/pnas.0913170107 (2010). 2 Mortensen, M., Soilleux, E. J., Djordjevic, G., Tripp, R., Lutteropp, M., Sadighi-Akha, E., Stranks, A. J., Glanville, J., Knight, S., Jacobsen, S. E., Kranc, K. R. & Simon, A. K. The autophagy protein Atg7 is essential for hematopoietic stem cell maintenance. J Exp Med 208, 455-467, doi:10.1084/jem.20101145 (2011). 3 Watson, A. S., Riffelmacher, T., Stranks, A., Williams, O., De Boer, J., Cain, K., MacFarlane, M., McGouran, J., Kessler, B., Khandwala, S., Chowdhury, O., Puleston, D., Phadwal, K., Mortensen, M., Ferguson, D., Soilleux, E., Woll, P., Jacobsen, S. E. & Simon, A. K. Autophagy limits proliferation and glycolytic metabolism in acute myeloid leukemia. Cell Death Discov 1, doi:10.1038/cddiscovery.2015.8 (2015). 4 Riffelmacher, T., Clarke, A., Richter, F. C., Stranks, A., Pandey, S., Danielli, S., Hublitz, P., Yu, Z. R., Johnson, E., Schwerd, T., McCullagh, J., Uhlig, H., Jacobsen, S. E. W. & Simon, A. K. Autophagy-Dependent Generation of Free Fatty Acids Is Critical for Normal Neutrophil Differentiation. Immunity 47, 466-480, doi:10.1016/j.immuni.2017.08.005 (2017). Disclosures No relevant conflicts of interest to declare.

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