bims-tremyl 2024-06-16 papers

bims-tremyl

Biomed News

on Therapy resistance biology in myeloid leukemia

Issue of 2024–06–16
24 papers selected by
Paolo Gallipoli, Barts Cancer Institute, Queen Mary University of London

Mis-splicing of mitotic regulators sensitizes SF3B1-mutated human HSCs to CHK1 inhibition.
The multi-kinase inhibitor CG-806 exerts anti-cancer activity against acute myeloid leukemia by co-targeting FLT3, BTK, and aurora kinases.
TP53 Y220C mutations in patients with myeloid malignancies.
Multi-target measurable residual disease assessed by error-corrected sequencing in patients with acute myeloid leukemia: An ALFA study.
Comparable relapse incidence after unrelated allogeneic stem cell transplantation with post-transplant cyclophosphamide versus conventional anti-graft versus host disease prophylaxis in patients with acute myeloid leukemia: A study on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.
Cytarabine dose intensification improves survival in older patients with secondary/high-risk acute myeloid leukemia in matched real-world versus clinical trial data.
CLONAL DYNAMICS AND RELAPSE RISK REVEALED BY HIGH SENSITIVITY FLT3-ITD DETECTION IN ACUTE MYELOID LEUKEMIA.
Venetoclax therapy and emerging resistance mechanisms in acute myeloid leukaemia.
Immune control in Acute Myeloid Leukaemia.
Neutrophil-specific expression of JAK2-V617F or CALRmut induces distinct inflammatory profiles in myeloproliferative neoplasia.
Myeloproliferative neoplasms in the adolescent and young adult population: A comprehensive review of the literature.
Charting epimutation dynamics in human hematopoietic differentiation.
Engineering an inducible leukemia-associated fusion protein enables large-scale ex vivo production of functional human phagocytes.
Evaluation of Acute Myeloid Leukemia Genomes using Genomic Proximity Mapping.
Electron transport chain inhibition increases cellular dependence on purine transport and salvage.
Venetoclax resistance leads to broad resistance to standard-of-care anti-MM agents, but not to immunotherapies.
Coenzyme A biosynthesis: mechanisms of regulation, function and disease.
Hairy cell leukemia variant and WHO classification correspondence Re: 5th edition WHO classification haematolymphoid tumors: lymphoid neoplasms.
Mathematical modelling, selection, and hierarchical inference to determine the minimal dose in IFNα therapy against Myeloproliferative Neoplasms.
ASS1 metabolically contributes to the nuclear and cytosolic p53-mediated DNA damage response.
Novel meriolin derivatives potently inhibit cell cycle progression and transcription in leukemia and lymphoma cells via inhibition of cyclin-dependent kinases (CDKs).
Metabolic inflexibility promotes mitochondrial health during liver regeneration.
Efficacy of the Allosteric MEK Inhibitor Trametinib in Relapsed and Refractory Juvenile Myelomonocytic Leukemia: a Report from the Children's Oncology Group.
The Bioenergetic Landscape of Cancer.

Blood Cancer Discov. 2024 Jun 10.

Mis-splicing of mitotic regulators sensitizes SF3B1-mutated human HSCs to CHK1 inhibition.

Martina Sarchi, Courtnee A Clough, Edie I Crosse, Jason Kim, Laura D Baquero Galvis, Nelli Aydinyan, Rachel Wellington, Feini Yang, Anna Galli, J Philip Creamer, Sintra Stewart, Robert K Bradley, Luca Malcovati, Sergei Doulatov.

Splicing factor SF3B1 mutations are frequent somatic lesions in myeloid neoplasms that transform hematopoietic stem cells (HSCs) by inducing mis-splicing of target genes. However, the molecular and functional consequences of SF3B1 mutations in human HSCs remain unclear. Here, we identify the mis-splicing program in human HSCs as a targetable vulnerability by precise gene editing of SF3B1 K700E mutations in primary CD34+ cells. Mutant SF3B1 induced pervasive mis-splicing and reduced expression of genes regulating mitosis and genome maintenance leading to altered differentiation, delayed G2/M progression, and profound sensitivity to CHK1 inhibition (CHK1i). Mis-splicing or reduced expression of mitotic regulators BUBR1 and CDC27 delayed G2/M transit and promoted CHK1i sensitivity. Clinical CHK1i prexasertib selectively targeted SF3B1-mutant HSCs and abrogated engraftment in vivo. These findings identify mis-splicing of mitotic regulators in SF3B1-mutant HSCs as a targetable vulnerability engaged by pharmacological CHK1 inhibition.

DOI: https://doi.org/10.1158/2643-3230.BCD-23-0230
Leuk Lymphoma. 2024 Jun 13. 1-16

The multi-kinase inhibitor CG-806 exerts anti-cancer activity against acute myeloid leukemia by co-targeting FLT3, BTK, and aurora kinases.

Guopan Yu, Weiguo Zhang, Mahesh Basyal, Yuki Nishida, Hideaki Mizumo, Charlie Ly, Hongying Zhang, William G Rice, Michael Andreeff.

  Despite the development of several Fms-like tyrosine kinase 3 (FLT3) inhibitors that have improved outcomes in patients with FLT3-mutant acute myeloid leukemia (AML), drug resistance is frequently observed, which may be associated with the activation of additional pro-survival pathways, such as those regulated by BTK, aurora kinases (AuroK), and potentially others, in addition to acquired tyrosine kinase domain (TKD) mutations of FLT3 gene. FLT3 may not always be a driver mutation. We evaluated the anti-leukemia efficacy of the novel multi-kinase inhibitor CG-806, which targets FLT3 and other kinases, to circumvent drug resistance and target FLT3 wild-type (WT) cells. The anti-leukemia activity of CG-806 was investigated by measuring apoptosis induction and analyzing the cell cycle using flow cytometry in vitro. CG-806 demonstrated superior anti-leukemia efficacy compared to commercially available FLT3 inhibitors, both in vitro and in vivo, regardless of FLT3 mutational status. The mechanism of action of CG-806 may involve its broad inhibitory profile against FLT3, BTK, and AuroK. In FLT3 mutant cells, CG-806 induced G1 phase blockage, whereas in FLT3 WT cells, it resulted in G2/M phase arrest. Targeting FLT3 and Bcl-2 and/or Mcl-1 simultaneously results in a synergistic pro-apoptotic effect in FLT3 mutant leukemia cells. The results of this study suggest that CG-806 is a promising multi-kinase inhibitor with anti-leukemic efficacy regardless of FLT3 mutational status. A phase 1 clinical trial of CG-806 for the treatment of AML has been initiated (NCT04477291).Key pointsThe multi-kinase inhibitor CG-806 exerts superior anti-leukemic activity in AML, regardless of its FLT3 status.CG-806 triggered G1 arrest in FLT3 mutated cells and G2/M arrest in FLT3 WT cells through the suppression of FLT3/BTK and aurora kinases.Concomitantly targeting FLT3 and Bcl-2 and/or Mcl-1 exerted synergistic pro-apoptotic effects on both FLT3 WT and mutated AML cells.

Keywords:  CG-806; FLT3; Multi-kinase inhibitor; acute myeloid leukemia

DOI:  https://doi.org/10.1080/10428194.2024.2364839
Leuk Lymphoma. 2024 Jun 10. 1-5

TP53 Y220C mutations in patients with myeloid malignancies.

Georgina Gener-Ricos, Jan P Bewersdorf, Sanam Loghavi, Alex Bataller, Aaron D Goldberg, Christopher Famulare, Koichi Takahashi, Ghayas C Issa, Gautam Borthakur, Tapan M Kadia, Nicholas J Short, Jayastu Senapati, Bing Z Carter, Keyur P Patel, Hagop Kantarjian, Michael Andreeff, Eytan M Stein, Courtney D DiNardo.



Keywords:  CCUS; CHIP; TP53 mutation; acute myeloid leukemia; myelodysplastic syndromes; myeloid neoplasms

DOI:  https://doi.org/10.1080/10428194.2024.2363440
Blood Cancer J. 2024 Jun 13. 14(1): 97

Multi-target measurable residual disease assessed by error-corrected sequencing in patients with acute myeloid leukemia: An ALFA study.

Pierre Hirsch, Jérôme Lambert, Maxime Bucci, Caroline Deswarte, Augustin Boudry, Juliette Lambert, Laurene Fenwarth, Jean-Baptiste Micol, Christine Terré, Karine Celli-Lebras, Xavier Thomas, Hervé Dombret, Nicolas Duployez, Claude Preudhomme, Raphael Itzykson, Francois Delhommeau.

The evaluation of measurable residual disease (MRD) in acute myeloid leukemia (AML) using comprehensive mutation analysis by next-generation sequencing (NGS) has been investigated in several studies. However controversial results exist regarding the detection of persisting mutations in DNMT3A, TET2, and ASXL1 (DTA). Benchmarking of NGS-MRD taking into account other molecular MRD strategies has to be done. Here, we performed error-corrected-NGS-MRD in 189 patients homogeneously treated in the ALFA-0702 study (NCT00932412). Persistence of non-DTA mutations (HR = 2.23 for RFS and 2.26 for OS), and DTA mutations (HR = 2.16 for OS) were associated with poorer prognosis in multivariate analysis. Persistence of at least two mutations in complete remission (CR) was associated with a higher cumulative incidence of relapse (CIR) (HR = 3.71, p < 0.0001), lower RFS (HR = 3.36, p < 0.0001) and OS (HR = 3.81, p = 0.00023) whereas persistence of only one mutation was not. In 100 analyzable patients, WT1-MRD, but not NGS-MRD, was an independent factor for RFS and OS. In the subset of 67 NPM1 mutated patients, both NPM1 mutation detection (p = 0.0059) and NGS-MRD (p = 0.035) status were associated with CIR. We conclude that detectable NGS-MRD including DTA mutations correlates with unfavorable prognosis in AML. Its integration with alternative MRD strategies in AML management warrants further investigations.

DOI: https://doi.org/10.1038/s41408-024-01078-8
Am J Hematol. 2024 Jun 10.

Comparable relapse incidence after unrelated allogeneic stem cell transplantation with post-transplant cyclophosphamide versus conventional anti-graft versus host disease prophylaxis in patients with acute myeloid leukemia: A study on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.

Arnon Nagler, Maud Ngoya, Jacques-Emmanuel Galimard, Myriam Labopin, Igor Wolfgang Blau, Nicolaus Kröger, Tobias Gedde-Dahl, Thomas Schroeder, David Burns, Urpu Salmenniemi, Alessandro Rambaldi, Goda Choi, Régis Peffault de Latour, Jan Vydra, Henrik Sengeloev, Matthias Eder, Stephan Mielke, Edouard Forcade, Alexander Kulagin, Fabio Ciceri, Mohamad Mohty.

We compared relapse incidence (RI) post-unrelated transplantation with post-transplant cyclophosphamide (PTCy) versus no PTCy graft-versus-host disease (GVHD) prophylaxis, in 7049 acute myeloid leukemia (AML) patients in remission, 707 with PTCy, and 6342 without (No PTCy). The patients in the PTCy group were younger, 52.7 versus 56.6 years (p < .001). There were more 9/10 donors in the PTCy group, 33.8% versus 16.4% (p < .001), and more received myeloablative conditioning, 61.7% versus 50.2% (p < .001). In the No PTCy group, 87.7% of patients received in vivo T-cell depletion. Neutrophil and platelet engraftment were lower in the PTCy versus No PTCy group, 93.8% and 80.9% versus 97.6% and 92.6% (p < .001). RI was not significantly different in the PTCy versus the No PTCy group, hazard ratio (HR) of 1.11 (95% confidence interval [CI] 0.9-1.37) (p = .31). Acute GVHD grades II-IV and III-IV, were significantly lower in the PTCy versus the No PTCy group, HR of 0.74 (95% CI 0.59-0.92, p = .007) and HR = 0.56 (95% CI 0.38-0.83, p = .004), as were total and extensive chronic GVHD, HRs of 0.5 (95% CI 0.41-0.62, p < .001) and HR = 0.31 (95% CI 0.22-0.42, p < .001). Non-relapse mortality (NRM) was significantly lower with PTCy versus the No PTCy group, HR of 0.67 (95% CI 0.5-0.91, p = .007). GVHD-free, relapse-free survival (GRFS) was higher in the PTCy versus the No PTCy group, HR of 0.69 (95% CI 0.59-0.81, p = .001). Leukemia-free survival (LFS) and overall survival (OS) did not differ between the groups. In summary, we observed comparable RI, OS, and LFS, significantly lower incidences of GVHD and NRM, and significantly higher GRFS in AML patients undergoing unrelated donor-hematopoietic stem cell transplantation with PTCy versus No PTCy GVHD prophylaxis.

DOI: https://doi.org/10.1002/ajh.27383
Leuk Lymphoma. 2024 Jun 11. 1-9

Cytarabine dose intensification improves survival in older patients with secondary/high-risk acute myeloid leukemia in matched real-world versus clinical trial data.

Christoph Abé, Jaana Keto, Mathias Lilja, Mie Konradsen, Johan Mesterton, Martin Höglund, Vladimir Lazarevic, Sören Lehmann, Gunnar Juliusson.

  Since 1980's, the established/standard treatment of acute myeloid leukemia (AML) is cytarabine infusion with anthracycline (7 + 3 regimen). We compared the 7 + 3 regimen in older secondary/high-risk AML patientsfrom a clinical trial with a matched population from the Swedish AML Registrytreated withan increased cytarabine dose in induction and consolidation as recommended in the Swedish National Guidelines since 2005. After successfulpropensity score matching, 104 patients per group were included. The primary outcome was overall survival (OS), and standard dosed patients had a median OS of 6.4 versus 10.7 months with increased dose intensity (hazard ratio:0.69, p = 0.012), with 5-year OS of 8.7% and 18.1%, andremission rates of 36% and 60%, respectively (p < 0.001). Median OS after allogeneic hematopoietic cell transplantation (in 27.9% per group) was 10.4 and 20.7 months, respectively. We conclude that the more intensive cytarabine schedule seems to provide improved outcomes inthe investigated AML patient group.

Keywords:  Conventional 7 + 3 regimen; external control arm; hematopoietic cell transplantation; overall survival; real-world data; standard of care

DOI:  https://doi.org/10.1080/10428194.2024.2363430
Mod Pathol. 2024 Jun 07. pii: S0893-3952(24)00114-5. [Epub ahead of print] 100534

CLONAL DYNAMICS AND RELAPSE RISK REVEALED BY HIGH SENSITIVITY FLT3-ITD DETECTION IN ACUTE MYELOID LEUKEMIA.

Kwadwo Asare Oduro, Theresa Spivey, Erika M Moore, Howard Meyerson, Jennifer Yoest, Benjamin Tomlinson, Rose Beck, David Alouani, Navid Sadri.

The ability to detect low level disease is key to our understanding of clonal heterogeneity in acute myeloid leukemia (AML) and residual disease that elude conventional assays and seed relapse. We have developed a high sensitivity next generation sequencing (HS-NGS) clinical assay, able to reliably detect low levels (1x10-5) of FLT3-ITD, a frequent, therapeutically targetable and prognostically relevant mutation in AML. By applying this assay to 289 longitudinal samples from 62 patients at initial diagnosis and/or clinical follow up (mean follow-up of 22 months) we reveal the frequent occurrence of FLT3-ITD subclones at diagnosis and demonstrate a significantly decreased relapse risk when FLT3-ITD is cleared after induction or thereafter. We perform pairwise sequencing of diagnosis and relapse samples from 23 patients to uncover more detailed patterns of FLT3-ITD clonal evolution at relapse than is detectable by less sensitive assays. Lastly, we show that rising ITD level during consecutive biopsies is a harbinger of impending relapse. Our findings corroborate the emerging clinical utility of high sensitivity FLT3-ITD testing and expands our understanding of clonal dynamics in FLT3-ITD positive AML.

DOI: https://doi.org/10.1016/j.modpat.2024.100534
Cell Death Dis. 2024 Jun 12. 15(6): 413

Venetoclax therapy and emerging resistance mechanisms in acute myeloid leukaemia.

Gus O Nwosu, David M Ross, Jason A Powell, Stuart M Pitson.

Acute myeloid leukaemia (AML) is a highly aggressive and devastating malignancy of the bone marrow and blood. For decades, intensive chemotherapy has been the frontline treatment for AML but has yielded only poor patient outcomes as exemplified by a 5-year survival rate of < 30%, even in younger adults. As knowledge of the molecular underpinnings of AML has advanced, so too has the development new strategies with potential to improve the treatment of AML patients. To date the most promising of these targeted agents is the BH3-mimetic venetoclax which in combination with standard of care therapies, has manageable non-haematological toxicity and exhibits impressive efficacy. However, approximately 30% of AML patients fail to respond to venetoclax-based regimens and almost all treatment responders eventually relapse. Here, we review the emerging mechanisms of intrinsic and acquired venetoclax resistance in AML and highlight recent efforts to identify novel strategies to overcome resistance to venetoclax.

DOI: https://doi.org/10.1038/s41419-024-06810-7
Exp Hematol. 2024 Jun 12. pii: S0301-472X(24)00115-2. [Epub ahead of print] 104256

Immune control in Acute Myeloid Leukaemia.

Jasmin Straube, Yashaswini Janardhanan, Rohit Haldar, Megan J Bywater.

Acute myeloid Leukaemia is a genetically heterogeneous disease, in that a multitude of oncogenic drivers and chromosomal abnormalities have been identified and associated with leukaemic transformation of myeloid blasts. However, little is known as to how individual mutations influence the interaction between the immune system and AML cells and the efficacy of the immune system in AML disease control. In this review we will discuss how AML cells potentially activate the immune system and what evidence there is to support a role of the immune system in controlling this disease. We will specifically examine the importance of antigen presentation in fostering an effective anti-AML immune response, explore the disruption of immune responses during AML disease progression and discuss the emerging role of the oncoprotein MYC in driving immune suppression in AML.

DOI: https://doi.org/10.1016/j.exphem.2024.104256
J Hematol Oncol. 2024 Jun 09. 17(1): 43

Neutrophil-specific expression of JAK2-V617F or CALRmut induces distinct inflammatory profiles in myeloproliferative neoplasia.

Tobias Ronny Haage, Emmanouil Charakopoulos, Vikas Bhuria, Conny K Baldauf, Mark Korthals, Juliane Handschuh, Peter Müller, Juan Li, Kunjan Harit, Gopala Nishanth, Stephanie Frey, Martin Böttcher, Klaus-Dieter Fischer, Jan Dudeck, Anne Dudeck, Daniel B Lipka, Burkhart Schraven, Anthony R Green, Andreas J Müller, Dimitrios Mougiakakos, Thomas Fischer.

   BACKGROUND: Neutrophils play a crucial role in inflammation and in the increased thrombotic risk in myeloproliferative neoplasms (MPNs). We have investigated how neutrophil-specific expression of JAK2-V617F or CALRdel re-programs the functions of neutrophils.
METHODS: Ly6G-Cre JAK2-V617F and Ly6G-Cre CALRdel mice were generated. MPN parameters as blood counts, splenomegaly and bone marrow histology were compared to wild-type mice. Megakaryocyte differentiation was investigated using lineage-negative bone marrow cells upon in vitro incubation with TPO/IL-1β. Cytokine concentrations in serum of mice were determined by Mouse Cytokine Array. IL-1α expression in various hematopoietic cell populations was determined by intracellular FACS analysis. RNA-seq to analyse gene expression of inflammatory cytokines was performed in isolated neutrophils from JAK2-V617F and CALR-mutated mice and patients. Bioenergetics of neutrophils were recorded on a Seahorse extracellular flux analyzer. Cell motility of neutrophils was monitored in vitro (time lapse microscopy), and in vivo (two-photon microscopy) upon creating an inflammatory environment. Cell adhesion to integrins, E-selectin and P-selection was investigated in-vitro. Statistical analysis was carried out using GraphPad Prism. Data are shown as mean ± SEM. Unpaired, two-tailed t-tests were applied.
RESULTS: Strikingly, neutrophil-specific expression of JAK2-V617F, but not CALRdel, was sufficient to induce pro-inflammatory cytokines including IL-1 in serum of mice. RNA-seq analysis in neutrophils from JAK2-V617F mice and patients revealed a distinct inflammatory chemokine signature which was not expressed in CALR-mutant neutrophils. In addition, IL-1 response genes were significantly enriched in neutrophils of JAK2-V617F patients as compared to CALR-mutant patients. Thus, JAK2-V617F positive neutrophils, but not CALR-mutant neutrophils, are pathogenic drivers of inflammation in MPN. In line with this, expression of JAK2-V617F or CALRdel elicited a significant difference in the metabolic phenotype of neutrophils, suggesting a stronger inflammatory activity of JAK2-V617F cells. Furthermore, JAK2-V617F, but not CALRdel, induced a VLA4 integrin-mediated adhesive phenotype in neutrophils. This resulted in reduced neutrophil migration in vitro and in an inflamed vessel. This mechanism may contribute to the increased thrombotic risk of JAK2-V617F patients compared to CALR-mutant individuals.
CONCLUSIONS: Taken together, our findings highlight genotype-specific differences in MPN-neutrophils that have implications for the differential pathophysiology of JAK2-V617F versus CALR-mutant disease.

Keywords:  CALR mutations; Inflammation; JAK2-V617F; MPN; Neutrophils

DOI:  https://doi.org/10.1186/s13045-024-01562-5
Br J Haematol. 2024 Jun 10.

Myeloproliferative neoplasms in the adolescent and young adult population: A comprehensive review of the literature.

Hannah Goulart, Lucia Masarova, Ruben Mesa, Claire Harrison, Jean-Jacques Kiladjian, Naveen Pemmaraju.

  Myeloproliferative neoplasms (MPN) are characterized by a clonal proliferation of myeloid lineage cells within the bone marrow. The classical BCR-ABL negative MPNs are comprised of polycythaemia vera, essential thrombocythaemia and primary myelofibrosis. Historically, the majority of MPNs are diagnosed in adults older than 60 years of age; however, in recent years, there has been recognition of MPNs in the adolescent and young adult (AYA) population. AYAs with MPN, typically defined as between the ages of 15 and 39 years old, may comprise up to 20% of patients diagnosed with MPN. They demonstrate unique patterns of driver mutations and thrombotic events and remain at risk for progression to more aggressive disease states. Given the likely long length of time they will live with their disease, there is a significant unmet need in identifying well-tolerated and effective treatment options for these patients, particularly with the advent of disease modification. In this review, we provide a comprehensive overview of the clinical features, disease course and management of AYA patients with MPN and, in doing so, highlight key characteristics that distinguish them from their older counterparts.

Keywords:  essential thrombocythaemia; myelofibrosis; myeloproliferative disease; myeloproliferative disorder; polycythaemia vera

DOI:  https://doi.org/10.1111/bjh.19557
Blood Sci. 2024 Jul;6(3): e00197

Charting epimutation dynamics in human hematopoietic differentiation.

Xiaohuan Qin, Jiayi Lu, Peng Wu, Chunyong Zhang, Lei Shi, Ping Zhu.

  DNA methylation plays a critical role in hematopoietic differentiation. Epimutation is a stochastic variation in DNA methylation that induces epigenetic heterogeneity. However, the effects of epimutations on normal hematopoiesis and hematopoietic diseases remain unclear. In this study, we developed a Julia package called EpiMut that enabled rapid and accurate quantification of epimutations. EpiMut was used to evaluate and provide an epimutation landscape in steady-state hematopoietic differentiation involving 13 types of blood cells ranging from hematopoietic stem/progenitor cells to mature cells. We showed that substantial genomic regions exhibited epigenetic variations rather than significant differences in DNA methylation levels between the myeloid and lymphoid lineages. Stepwise dynamics of epimutations were observed during the differentiation of each lineage. Importantly, we found that epimutation significantly enriched signals associated with lineage differentiation. Furthermore, epimutations in hematopoietic stem cells (HSCs) derived from various sources and acute myeloid leukemia were related to the function of HSCs and malignant cell disorders. Taken together, our study comprehensively documented an epimutation map and uncovered its important roles in human hematopoiesis, thereby offering insights into hematopoietic regulation.

Keywords:  DNA methylation; Epimutation; Hematopoietic differentiation; Hematopoietic stem cell

DOI:  https://doi.org/10.1097/BS9.0000000000000197
Proc Natl Acad Sci U S A. 2024 Jun 18. 121(25): e2312499121

Engineering an inducible leukemia-associated fusion protein enables large-scale ex vivo production of functional human phagocytes.

Roland Windisch, Sarah Soliman, Adrian Hoffmann, Linping Chen-Wichmann, Anna Danese, Sebastian Vosberg, Jimena Bravo, Sebastian Lutz, Christian Kellner, Alexander Fischer, Claudia Gebhard, Enric Redondo Monte, Luise Hartmann, Stephanie Schneider, Fabian Beier, Carolin Dorothea Strobl, Oliver Weigert, Matthias Peipp, Michael Schündeln, Stefan H Stricker, Michael Rehli, Jürgen Bernhagen, Andreas Humpe, Hannes Klump, Christian Brendel, Daniela S Krause, Philipp A Greif, Christian Wichmann.

  Ex vivo expansion of human CD34+ hematopoietic stem and progenitor cells remains a challenge due to rapid differentiation after detachment from the bone marrow niche. In this study, we assessed the capacity of an inducible fusion protein to enable sustained ex vivo proliferation of hematopoietic precursors and their capacity to differentiate into functional phagocytes. We fused the coding sequences of an FK506-Binding Protein 12 (FKBP12)-derived destabilization domain (DD) to the myeloid/lymphoid lineage leukemia/eleven nineteen leukemia (MLL-ENL) fusion gene to generate the fusion protein DD-MLL-ENL and retrovirally expressed the protein switch in human CD34+ progenitors. Using Shield1, a chemical inhibitor of DD fusion protein degradation, we established large-scale and long-term expansion of late monocytic precursors. Upon Shield1 removal, the cells lost self-renewal capacity and spontaneously differentiated, even after 2.5 y of continuous ex vivo expansion. In the absence of Shield1, stimulation with IFN-γ, LPS, and GM-CSF triggered terminal differentiation. Gene expression analysis of the obtained phagocytes revealed marked similarity with naïve monocytes. In functional assays, the novel phagocytes migrated toward CCL2, attached to VCAM-1 under shear stress, produced reactive oxygen species, and engulfed bacterial particles, cellular particles, and apoptotic cells. Finally, we demonstrated Fcγ receptor recognition and phagocytosis of opsonized lymphoma cells in an antibody-dependent manner. Overall, we have established an engineered protein that, as a single factor, is useful for large-scale ex vivo production of human phagocytes. Such adjustable proteins have the potential to be applied as molecular tools to produce functional immune cells for experimental cell-based approaches.

Keywords:  CD34+; MLL1; cellular differentiation; human blood progenitors; macrophages

DOI:  https://doi.org/10.1073/pnas.2312499121
medRxiv. 2024 Jun 01. pii: 2024.05.31.24308228. [Epub ahead of print]

Evaluation of Acute Myeloid Leukemia Genomes using Genomic Proximity Mapping.

Cecilia Cs Yeung, Stephen M Eacker, Olga Sala-Torra, Lan Beppu, David W Woolston, Ivan Liachko, Maika Malig, Derek Stirewalt, Min Fang, Jerald Radich.

   Background: Cytogenetic analysis encompasses a suite of standard-of-care diagnostic testing methods that is routinely applied in cases of acute myeloid leukemia (AML) to assess chromosomal changes that are clinically relevant for risk classification and treatment decisions.
Objective: In this study, we assess the use of Genomic Proximity Mapping (GPM) for cytogenomic analysis of AML diagnostic specimens for detection of cytogenetic risk variants included in the European Leukemia Network (ELN) risk stratification guidelines.
Methods: Archival patient samples (N=48) from the Fred Hutchinson Cancer Center leukemia bank with historical clinical cytogenetic data were processed for GPM and analyzed with the CytoTerra® cloud-based analysis platform.
Results: GPM showed 100% concordance for all specific variants that have associated impacts on risk stratification as defined by ELN 2022 criteria, and a 72% concordance rate when considering all variants reported by the FH cytogenetic lab. GPM identified 39 additional variants, including variants of known clinical impact, not observed by cytogenetics.
Conclusions: GPM is an effective solution for the evaluation of known AML-associated risk variants and a source for biomarker discovery.

Keywords:  AML; Acute myeloid leukemia; genomic profiling; genomic proximity mapping; molecular genetics pathology

DOI:  https://doi.org/10.1101/2024.05.31.24308228
Cell Metab. 2024 Jun 07. pii: S1550-4131(24)00190-6. [Epub ahead of print]

Electron transport chain inhibition increases cellular dependence on purine transport and salvage.

Zheng Wu, Divya Bezwada, Feng Cai, Robert C Harris, Bookyung Ko, Varun Sondhi, Chunxiao Pan, Hieu S Vu, Phong T Nguyen, Brandon Faubert, Ling Cai, Hongli Chen, Misty Martin-Sandoval, Duyen Do, Wen Gu, Yuanyuan Zhang, Yuannyu Zhang, Bailey Brooks, Sherwin Kelekar, Lauren G Zacharias, K Celeste Oaxaca, Joao S Patricio, Thomas P Mathews, Javier Garcia-Bermudez, Min Ni, Ralph J DeBerardinis.

  Mitochondria house many metabolic pathways required for homeostasis and growth. To explore how human cells respond to mitochondrial dysfunction, we performed metabolomics in fibroblasts from patients with various mitochondrial disorders and cancer cells with electron transport chain (ETC) blockade. These analyses revealed extensive perturbations in purine metabolism, and stable isotope tracing demonstrated that ETC defects suppress de novo purine synthesis while enhancing purine salvage. In human lung cancer, tumors with markers of low oxidative mitochondrial metabolism exhibit enhanced expression of the salvage enzyme hypoxanthine phosphoribosyl transferase 1 (HPRT1) and high levels of the HPRT1 product inosine monophosphate. Mechanistically, ETC blockade activates the pentose phosphate pathway, providing phosphoribosyl diphosphate to drive purine salvage supplied by uptake of extracellular bases. Blocking HPRT1 sensitizes cancer cells to ETC inhibition. These findings demonstrate how cells remodel purine metabolism upon ETC blockade and uncover a new metabolic vulnerability in tumors with low respiration.

Keywords:  HPRT1; NAD(+):NADH ratio; electron transport chain; metabolomics; purine metabolism; stable isotopes

DOI:  https://doi.org/10.1016/j.cmet.2024.05.014
Blood Adv. 2024 Jun 11. pii: bloodadvances.2023012298. [Epub ahead of print]

Venetoclax resistance leads to broad resistance to standard-of-care anti-MM agents, but not to immunotherapies.

Shuhui Deng, Sanika Derebail, Vera Joy Weiler, Jessica Fong Ng, Elena Maroto-Martin, Madhumouli Chatterjee, Giulia Giorgetti, Chandraditya Chakraborty, Poonam Kalhotra, Ting Du, Yao Yao, Rao H Prabhala, Masood A Shammas, Annamaria Gulla, Anil Aktas Samur, Mehmet K Samur, Lugui Qiu, Kenneth C Anderson, Mariateresa Fulciniti, Nikhil C Munshi.

Venetoclax is the first example of personalized medicine for multiple myeloma (MM), with meaningful clinical activity as a monotherapy and in combination in myeloma patients harboring the t(11:14) translocation. However, despite the high response rates and prolonged PFS, a significant proportion of patients eventually relapse. Here, we aimed to study adaptive molecular responses after the acquisition of venetoclax resistance in sensitive t(11:14) MM cell models. We therefore generated single-cell venetoclax-resistant t(11:14) MM cell lines and investigated the mechanisms contributing to resistance as well as the cells' sensitivity to other treatments. Our data suggests that acquired resistance to venetoclax is characterized by reduced mitochondrial priming and changes in BCL-2 family proteins' expression in MM cells, conferring broad resistance to standard-of-care anti-myeloma drugs. However, our results show that the resistant cells are still sensitive to immunotherapeutic treatments, highlighting the need to consider appropriate sequencing of these treatments following venetoclax-based regimens.

DOI: https://doi.org/10.1182/bloodadvances.2023012298
Nat Metab. 2024 Jun 13.

Coenzyme A biosynthesis: mechanisms of regulation, function and disease.

Samuel A Barritt, Sarah E DuBois-Coyne, Christian C Dibble.

The tricarboxylic acid cycle, nutrient oxidation, histone acetylation and synthesis of lipids, glycans and haem all require the cofactor coenzyme A (CoA). Although the sources and regulation of the acyl groups carried by CoA for these processes are heavily studied, a key underlying question is less often considered: how is production of CoA itself controlled? Here, we discuss the many cellular roles of CoA and the regulatory mechanisms that govern its biosynthesis from cysteine, ATP and the essential nutrient pantothenate (vitamin B5), or from salvaged precursors in mammals. Metabolite feedback and signalling mechanisms involving acetyl-CoA, other acyl-CoAs, acyl-carnitines, MYC, p53, PPARα, PINK1 and insulin- and growth factor-stimulated PI3K-AKT signalling regulate the vitamin B5 transporter SLC5A6/SMVT and CoA biosynthesis enzymes PANK1, PANK2, PANK3, PANK4 and COASY. We also discuss methods for measuring CoA-related metabolites, compounds that target CoA biosynthesis and diseases caused by mutations in pathway enzymes including types of cataracts, cardiomyopathy and neurodegeneration (PKAN and COPAN).

DOI: https://doi.org/10.1038/s42255-024-01059-y
Leukemia. 2024 Jun 08.

Hairy cell leukemia variant and WHO classification correspondence Re: 5th edition WHO classification haematolymphoid tumors: lymphoid neoplasms.

Michael Grever, Leslie Andritsos, Mirela Anghelina, Evgeny Arons, Versha Banerji, Jacqueline Barrientos, Seema A Bhat, James Blachly, Alessandro Broccoli, Timothy Call, Claire Dearden, Sascha Dietrich, Monica Else, Narendranath Epperla, Andrei Fagarasanu, Brunangelo Falini, Francesco Forconi, Alessandro Gozzetti, Paul Hampel, David J Hermel, Sunil Iyengar, James B Johnston, Gunnar Juliusson, Robert J Kreitman, Francesco Lauria, Gerard Lozanski, Christopher C Oakes, Sameer A Parikh, Jae Park, Graeme Quest, Kanti Rai, Farhad Ravandi, Tadeusz Robak, Kerry A Rogers, Alan Saven, John F Seymour, Tamar Tadmor, Martin S Tallman, Constantine S Tam, Enrico Tiacci, Xavier Troussard, Bernhard Wörmann, Clive S Zent, Thorsten Zenz, Pier Luigi Zinzani.

DOI: https://doi.org/10.1038/s41375-024-02280-0
Math Med Biol. 2024 Jun 14. pii: dqae006. [Epub ahead of print]

Mathematical modelling, selection, and hierarchical inference to determine the minimal dose in IFNα therapy against Myeloproliferative Neoplasms.

Gurvan Hermange, William Vainchenker, Isabelle Plo, Paul-Henry Cournède.

Myeloproliferative Neoplasms (MPN) are blood cancers that appear after acquiring a driver mutation in a hematopoietic stem cell. These hematological malignancies result in the overproduction of mature blood cells and, if not treated, induce a risk of cardiovascular events and thrombosis. Pegylated IFNα is commonly used to treat MPN, but no clear guidelines exist concerning the dose prescribed to patients. We applied a model selection procedure and ran a hierarchical Bayesian inference method to decipher how dose variations impact the response to the therapy. We inferred that IFNα acts on mutated stem cells by inducing their differentiation into progenitor cells; the higher the dose, the higher the effect. We found that the treatment can induce long-term remission when a sufficient (patient-dependent) dose is reached. We determined this minimal dose for individuals in a cohort of patients and estimated the most suitable starting dose to give to a new patient to increase the chances of being cured.

DOI: https://doi.org/10.1093/imammb/dqae006
Nat Metab. 2024 Jun 10.

ASS1 metabolically contributes to the nuclear and cytosolic p53-mediated DNA damage response.

Lisha Qiu Jin Lim, Lital Adler, Emma Hajaj, Leandro R Soria, Rotem Ben-Tov Perry, Naama Darzi, Ruchama Brody, Noa Furth, Michal Lichtenstein, Elizabeta Bab-Dinitz, Ziv Porat, Tevie Melman, Alexander Brandis, Yael Aylon, Shifra Ben-Dor, Irit Orr, Amir Pri-Or, Rony Seger, Yoav Shaul, Eytan Ruppin, Moshe Oren, Minervo Perez, Jordan Meier, Nicola Brunetti-Pierri, Efrat Shema, Igor Ulitsky, Ayelet Erez, Sergey Malitsky, Maxim Itkin.

Downregulation of the urea cycle enzyme argininosuccinate synthase (ASS1) in multiple tumors is associated with a poor prognosis partly because of the metabolic diversion of cytosolic aspartate for pyrimidine synthesis, supporting proliferation and mutagenesis owing to nucleotide imbalance. Here, we find that prolonged loss of ASS1 promotes DNA damage in colon cancer cells and fibroblasts from subjects with citrullinemia type I. Following acute induction of DNA damage with doxorubicin, ASS1 expression is elevated in the cytosol and the nucleus with at least a partial dependency on p53; ASS1 metabolically restrains cell cycle progression in the cytosol by restricting nucleotide synthesis. In the nucleus, ASS1 and ASL generate fumarate for the succination of SMARCC1, destabilizing the chromatin-remodeling complex SMARCC1-SNF5 to decrease gene transcription, specifically in a subset of the p53-regulated cell cycle genes. Thus, following DNA damage, ASS1 is part of the p53 network that pauses cell cycle progression, enabling genome maintenance and survival. Loss of ASS1 contributes to DNA damage and promotes cell cycle progression, likely contributing to cancer mutagenesis and, hence, adaptability potential.

DOI: https://doi.org/10.1038/s42255-024-01060-5
Cell Death Discov. 2024 Jun 11. 10(1): 279

Novel meriolin derivatives potently inhibit cell cycle progression and transcription in leukemia and lymphoma cells via inhibition of cyclin-dependent kinases (CDKs).

Laura Schmitt, Julia Hoppe, Pablo Cea-Medina, Peter-Martin Bruch, Karina S Krings, Ilka Lechtenberg, Daniel Drießen, Christoph Peter, Sanil Bhatia, Sascha Dietrich, Björn Stork, Gerhard Fritz, Holger Gohlke, Thomas J J Müller, Sebastian Wesselborg.

A key feature of cancer is the disruption of cell cycle regulation, which is characterized by the selective and abnormal activation of cyclin-dependent kinases (CDKs). Consequently, targeting CDKs via meriolins represents an attractive therapeutic approach for cancer therapy. Meriolins represent a semisynthetic compound class derived from meridianins and variolins with a known CDK inhibitory potential. Here, we analyzed the two novel derivatives meriolin 16 and meriolin 36 in comparison to other potent CDK inhibitors and could show that they displayed a high cytotoxic potential in different lymphoma and leukemia cell lines as well as in primary patient-derived lymphoma and leukemia cells. In a kinome screen, we showed that meriolin 16 and 36 prevalently inhibited most of the CDKs (such as CDK1, 2, 3, 5, 7, 8, 9, 12, 13, 16, 17, 18, 19, 20). In drug-to-target modeling studies, we predicted a common binding mode of meriolin 16 and 36 to the ATP-pocket of CDK2 and an additional flipped binding for meriolin 36. We could show that cell cycle progression and proliferation were blocked by abolishing phosphorylation of retinoblastoma protein (a major target of CDK2) at Ser612 and Thr82. Moreover, meriolin 16 prevented the CDK9-mediated phosphorylation of RNA polymerase II at Ser2 which is crucial for transcription initiation. This renders both meriolin derivatives as valuable anticancer drugs as they target three different Achilles' heels of the tumor: (1) inhibition of cell cycle progression and proliferation, (2) prevention of transcription, and (3) induction of cell death.

DOI: https://doi.org/10.1038/s41420-024-02056-6
Science. 2024 Jun 14. 384(6701): eadj4301

Metabolic inflexibility promotes mitochondrial health during liver regeneration.

Xun Wang, Cameron J Menezes, Yuemeng Jia, Yi Xiao, Siva Sai Krishna Venigalla, Feng Cai, Meng-Hsiung Hsieh, Wen Gu, Liming Du, Jessica Sudderth, Dohun Kim, Spencer D Shelton, Claire B Llamas, Yu-Hsuan Lin, Min Zhu, Salma Merchant, Divya Bezwada, Sherwin Kelekar, Lauren G Zacharias, Thomas P Mathews, Gerta Hoxhaj, R Max Wynn, Uttam K Tambar, Ralph J DeBerardinis, Hao Zhu, Prashant Mishra.

Mitochondria are critical for proper organ function and mechanisms to promote mitochondrial health during regeneration would benefit tissue homeostasis. We report that during liver regeneration, proliferation is suppressed in electron transport chain (ETC)-dysfunctional hepatocytes due to an inability to generate acetyl-CoA from peripheral fatty acids through mitochondrial β-oxidation. Alternative modes for acetyl-CoA production from pyruvate or acetate are suppressed in the setting of ETC dysfunction. This metabolic inflexibility forces a dependence on ETC-functional mitochondria and restoring acetyl-CoA production from pyruvate is sufficient to allow ETC-dysfunctional hepatocytes to proliferate. We propose that metabolic inflexibility within hepatocytes can be advantageous by limiting the expansion of ETC-dysfunctional cells.

DOI: https://doi.org/10.1126/science.adj4301
Cancer Discov. 2024 Jun 11. OF1-OF9

Efficacy of the Allosteric MEK Inhibitor Trametinib in Relapsed and Refractory Juvenile Myelomonocytic Leukemia: a Report from the Children's Oncology Group.

Elliot Stieglitz, Alex G Lee, Steven P Angus, Christopher Davis, Donald A Barkauskas, David Hall, Scott C Kogan, Julia Meyer, Steven D Rhodes, Sarah K Tasian, Xiaoling Xuei, Kevin Shannon, Mignon L Loh, Elizabeth Fox, Brenda J Weigel.

Juvenile myelomonocytic leukemia (JMML) is a hematologic malignancy of young children caused by mutations that increase Ras signaling output. Hematopoietic stem cell transplantation (HSCT) is a potentially curative treatment, but patients with relapsed or refractory (advanced) disease have dismal outcomes. This phase II trial evaluated the safety and efficacy of trametinib, an oral MEK1/2 inhibitor, in patients with advanced JMML. Ten infants and children were enrolled, and the objective response rate was 50%. Four patients with refractory disease proceeded to HSCT after receiving trametinib. Three additional patients completed all 12 cycles permitted on study and continue to receive off-protocol trametinib without HSCT. The remaining three patients had progressive disease with two demonstrating molecular evolution by the end of cycle 2. Transcriptomic and proteomic analyses provided novel insights into the mechanisms of response and resistance to trametinib in JMML. ClinicalTrials.gov Identifier: NCT03190915. Significance: Trametinib was safe and effective in young children with relapsed or refractory JMML, a lethal disease with poor survival rates. Seven of 10 patients completed the maximum 12 cycles of therapy or used trametinib as a bridge to HSCT and are alive with a median follow-up of 24 months.

DOI: https://doi.org/10.1158/2159-8290.CD-23-1376
Mol Metab. 2024 Jun 12. pii: S2212-8778(24)00097-8. [Epub ahead of print] 101966

The Bioenergetic Landscape of Cancer.

Elizabeth R M Zunica, Christopher L Axelrod, L Anne Gilmore, Erich Gnaiger, John P Kirwan.

  Bioenergetic remodeling of core energy metabolism is essential to the initiation, survival, and progression of cancer cells through exergonic supply of adenosine triphosphate (ATP) and metabolic intermediates, as well as control of redox homeostasis. Mitochondria are evolutionarily conserved organelles that mediate cell survival by conferring energetic plasticity and adaptive potential. Mitochondrial ATP synthesis is coupled to the oxidation of a variety of substrates generated through diverse metabolic pathways. As such, inhibition of the mitochondrial bioenergetic system by restricting metabolite availability, direct inhibition of the respiratory Complexes, altering organelle structure, or coupling efficiency may restrict carcinogenic potential and cancer progression. Here, we review the role of bioenergetics as the principal conductor of energetic functions and carcinogenesis while highlighting the therapeutic potential of targeting mitochondrial functions.

Keywords:  Bioenergetics; Cancer; Cell Survival; Energy Transformation; Mitochondria

DOI:  https://doi.org/10.1016/j.molmet.2024.101966