bims-tremyl Biomed News
on Therapy resistance biology in myeloid leukemia
Issue of 2023‒02‒26
thirty-one papers selected by
Paolo Gallipoli
Barts Cancer Institute, Queen Mary University of London
  1. Outcome prediction by the 2022 European LeukemiaNet genetic-risk classification for adults with acute myeloid leukemia: an Alliance study.
  2. Dipeptidylpeptidase 4 promotes survival and stemness of acute myeloid leukemia stem cells.
  3. PHF6 mutations in myelodysplastic syndromes, chronic myelomonocytic leukemia and acute myeloid leukemia.
  4. Single-center, observational study of AML/MDS-EB with IDH1/2 mutations: genetic profile, immunophenotypes, mutational kinetics and outcomes.
  5. An Update on FLT3 in Acute Myeloid Leukemia: Pathophysiology and Therapeutic Landscape.
  6. Clinical Implications of the FLT3-ITD Allelic Ratio in Acute Myeloid Leukemia in the Context of an Allogeneic Stem Cell Transplantation.
  7. Nanoparticle-mediated targeting of the fusion gene RUNX1/ETO in t(8;21)-positive acute myeloid leukaemia.
  8. Why do we not have more drugs approved for MDS? A critical viewpoint on novel drug development in MDS.
  9. Synergistic activity and mechanism of cytarabine and MCL-1 inhibitor AZD5991 against acute myeloid leukemia.
  10. Allogeneic stem cell transplantation for patients with acute myeloid leukemia (AML) in second complete remission (CR2) transplanted from unrelated donors with post-transplant cyclophosphamide (PTCy). A study on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.
  11. Survival of TP53-mutated acute myeloid leukemia patients receiving allogeneic stem cell transplantation after first induction or salvage therapy: results from the Consortium on Myeloid Malignancies and Neoplastic Diseases (COMMAND).
  12. Impact of trisomy 19 on outcome according to genetic makeup in patients with acute myeloid leukemia.
  13. Human gene-engineered calreticulin mutant stem cells recapitulate MPN hallmarks and identify targetable vulnerabilities.
  14. TAK-981, a SUMOylation inhibitor, suppresses AML growth immune-independently.
  15. Proteomic characterization of acute myeloid leukemia for precision medicine.
  16. Phenotypic Characterization of Disease-Initiating Stem Cells in JAK2- or CALR-mutated Myeloproliferative Neoplasms.
  17. Comprehensive molecular and clinical characterization of NUP98 fusions in pediatric acute myeloid leukemia.
  18. Efficacy analysis of different FLT3 inhibitors in patients with relapsed/refractory acute myeloid leukemia and high-risk myelodysplastic syndrome.
  19. MDS subclassification-do we still have to count blasts?
  20. Reversal of malignant ADAR1 splice isoform switching with Rebecsinib.
  21. High expression of an intragenic long noncoding RNA misinterpreted as high FTO oncogene expression in NPM1 mutant acute myeloid leukemia.
  22. Sex Disparities in Myelodysplastic Syndromes: Genotype, Phenotype, and Outcomes.
  23. Comparison between azacitidine and decitabine as front-line therapy in elderly acute myeloid leukemia patients not eligible for intensive chemotherapy.
  24. PI3-kinase deletion promotes myelodysplasia by dysregulating autophagy in hematopoietic stem cells.
  25. Stochastic fate decisions of HSCs after transplantation: early contribution, symmetric expansion, and pool formation.
  26. Physioxia improves the selectivity of hematopoietic stem cell expansion cultures.
  27. GSK3 inhibitor enhances gemtuzumab ozogamicin-induced apoptosis in primary human leukemia cells by overcoming multiple mechanisms of resistance.
  28. Human hematopoietic stem cell vulnerability to ferroptosis.
  29. Chemically defined cytokine-free expansion of human haematopoietic stem cells.
  30. CD40 signal rewires fatty acid and glutamine metabolism for stimulating macrophage anti-tumorigenic functions.
  31. Depletion of creatine phosphagen energetics with a covalent creatine kinase inhibitor.
  1. Leukemia. 2023 Feb 23.
    Outcome prediction by the 2022 European LeukemiaNet genetic-risk classification for adults with acute myeloid leukemia: an Alliance study.
    Krzysztof Mrózek, Jessica Kohlschmidt, James S Blachly, Deedra Nicolet, Andrew J Carroll, Kellie J Archer, Alice S Mims, Karilyn T Larkin, Shelley Orwick, Christopher C Oakes, Jonathan E Kolitz, Bayard L Powell, William G Blum, Guido Marcucci, Maria R Baer, Geoffrey L Uy, Wendy Stock, John C Byrd, Ann-Kathrin Eisfeld.
      Recently, the European LeukemiaNet (ELN) revised its genetic-risk classification of acute myeloid leukemia (AML). We categorized 1637 adults with AML treated with cytarabine/anthracycline regimens according to the 2022 and 2017 ELN classifications. Compared with the 2017 ELN classification, 2022 favorable group decreased from 40% to 35% and adverse group increased from 37% to 41% of patients. The 2022 genetic-risk groups seemed to accurately reflect treatment outcomes in all patients and patients aged <60 years, but in patients aged ≥60 years, relapse rates, disease-free (DFS) and overall (OS) survival were not significantly different between intermediate and adverse groups. In younger African-American patients, DFS and OS did not differ between intermediate-risk and adverse-risk patients nor did DFS between favorable and intermediate groups. In Hispanic patients, DFS and OS did not differ between favorable and intermediate groups. Outcome prediction abilities of 2022 and 2017 ELN classifications were similar. Among favorable-risk patients, myelodysplasia-related mutations did not affect patients with CEBPAbZIP mutations or core-binding factor AML, but changed risk assignment of NPM1-mutated/FLT3-ITD-negative patients to intermediate. NPM1-mutated patients with adverse-risk cytogenetic abnormalities were closer prognostically to the intermediate than adverse group. Our analyses both confirm and challenge prognostic significance of some of the newly added markers.
    DOI:  https://doi.org/10.1038/s41375-023-01846-8
  2. Cell Rep. 2023 Feb 17. pii: S2211-1247(23)00116-X. [Epub ahead of print]42(2): 112105
    Dipeptidylpeptidase 4 promotes survival and stemness of acute myeloid leukemia stem cells.
    Chen Wang, Ravi Nistala, Min Cao, Yi Pan, Madelaine Behrens, Donald Doll, Richard D Hammer, Puja Nistala, Hui-Ming Chang, Edward T H Yeh, XunLei Kang.
      Leukemic-stem-cell-specific targeting may improve the survival of patients with acute myeloid leukemia (AML) by avoiding the ablative effects of standard regimens on normal hematopoiesis. Herein, we perform an unbiased screening of compounds targeting cell surface proteins and identify clinically used DPP4 inhibitors as strong suppressors of AML development in both murine AML models and primary human AML cells xenograft model. We find in retrovirus-induced AML mouse models that DPP4-deficient AML cell-transplanted mice exhibit delay and reversal of AML development, whereas deletion of DPP4 has no significant effect on normal hematopoiesis. DPP4 activates and sustains survival of AML stem cells that are critical for AML development in both human and animal models via binding with Src kinase and activation of nuclear factor κB (NF-κB) signaling. Thus, inhibition of DPP4 is a potential therapeutic strategy against AML development through suppression of survival and stemness of AML cells.
    Keywords:  AML; CP: Cancer; DPP4; DPP4 inhibitors; apoptosis; cell surface protein; hematopoietic stem cell; leukemic stem cell; linagliptin; normal hematopoiesis; stemness
    DOI:  https://doi.org/10.1016/j.celrep.2023.112105
  3. Leuk Res. 2023 Feb 15. pii: S0145-2126(23)00029-2. [Epub ahead of print]127 107044
    PHF6 mutations in myelodysplastic syndromes, chronic myelomonocytic leukemia and acute myeloid leukemia.
    Alex Bataller, Kelly S Chien, Koji Sasaki, Guillermo Montalban-Bravo, Rashmi Kanagal-Shamanna, Samuel Urrutia, Emmanuel Almanza-Huante, Georgina Gener-Ricos, Farhad Ravandi, Elias Jabbour, Tapan Kadia, Gautam Borthakur, Guillermo Garcia-Manero.
      
    Keywords:  AML; CMML; MDS; PHF6
    DOI:  https://doi.org/10.1016/j.leukres.2023.107044
  4. Hematology. 2023 Dec;28(1): 2180704
    Single-center, observational study of AML/MDS-EB with IDH1/2 mutations: genetic profile, immunophenotypes, mutational kinetics and outcomes.
    Vasiliki Papadopoulou, Jacqueline Schoumans, Valentin Basset, Françoise Solly, Jérôme Pasquier, Sabine Blum, Olivier Spertini.
      OBJECTIVE: IDH1/2 mutations, intervening in epigenetic procedures, are frequently encountered in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). Knowledge of the genetics, immunophenotypes, and mutational kinetics of IDH1/2-mutated AML can contribute to the understanding of AML clonal architecture and inform therapeutics and monitoring.METHODS: We retrospectively analyzed 50 IDH1/2-mutated AML/MDS-EB cases of our institution, to identify recurrent co-mutations, immunophenotypes, patterns of co-variance of IDH1/2 allele burdens with those of recurrent co-mutations, frequency of persistent IDH1/2 mutation as clonal hematopoiesis of indeterminate potential (CHIP) in remission and response to hypomethylating agents.
    RESULTS: Most frequently co-mutated genes were DNMT3A, SRSF2 and NPM1. Most cases with co-existent IDH1/2 and NPM1 mutations (11/13) showed an 'APL-like' immunophenotype (CD34-HLADR-). Allele burdens of mutated IDH1/2 were identical to mutated SRSF2 allele burdens at diagnosis and remission, but not always to mutated NPM1 allele burden in remission. We show persistence of significant mutIDH1/2 allele burden in approximately one-fourth of patients with deep remissions. IDH1/2 mutations were significantly more frequent among responders to first-line HMA-based regimens than among non-responders, in patients treated for myeloid neoplasms with excess blasts.
    CONCLUSIONS: IDH1/2 mutations are most frequently accompanied by DNMT3A, SRSF2 and NPM1 mutations. NPM1-IDH1/2 mutated AML has a mature phenotype possibly amenable to differentiation therapies. IDH1/2 and SRSF2 mutations probably arise at the same developmental stage of the disease, as their allele burdens covariate. IDH1/2 mutation represents CHIP in a substantial proportion of cases and is therefore no reliable residual disease marker. The preferential presence of IDH1/2 mutations among HMA-responders could inform therapeutic decisions if confirmed in larger series.
    Keywords:  Acute myeloid leukemia; CHIP; Double-negative phenotype; IDH1/2
    DOI:  https://doi.org/10.1080/16078454.2023.2180704
  5. Curr Oncol Rep. 2023 Feb 18.
    An Update on FLT3 in Acute Myeloid Leukemia: Pathophysiology and Therapeutic Landscape.
    Rebecca Bystrom, Mark J Levis.
      PURPOSE OF REVIEW: This review aims to summarize the pathophysiology, clinical presentation, and management of acute myeloid leukemia (AML) with FMS-like tyrosine kinase-3 (FLT3) mutations.RECENT FINDINGS: The recent European Leukemia Net (ELN2022) recommendations re-classified AML with FLT3 internal tandem duplications (FLT3-ITD) as intermediate risk regardless of Nucleophosmin 1 (NPM1) co-mutation or the FLT3 allelic ratio. Allogeneic hematopoietic cell transplantation (alloHCT) is now recommended for all eligible patients with FLT3-ITD AML. This review outlines the role of FLT3 inhibitors in induction and consolidation, as well as for post-alloHCT maintenance. It outlines the unique challenges and advantages of assessing FLT3 measurable residual disease (MRD) and discusses the pre-clinical basis for the combination of FLT3 and menin inhibitors. And, for the older or unfit patient ineligible for upfront intensive chemotherapy, it discusses the recent clinical trials incorporating FLT3 inhibitors into azacytidine- and venetoclax-based regimens. Finally, it proposes a rational sequential approach for integrating FLT3 inhibitors into less intensive regimens, with a focus on improved tolerability in the older and unfit patient population. The management of AML with FLT3 mutation remains a challenge in clinical practice. This review provides an update on the pathophysiology and therapeutic landscape of FLT3 AML, as well as a clinical management framework for managing the older or unfit patient ineligible for intensive chemotherapy.
    Keywords:  Acute myelogenous leukemia; Acute myeloid leukemia; Azacitidine; FLT3 mutation; Unfit patient; Venetoclax
    DOI:  https://doi.org/10.1007/s11912-023-01389-2
  6. Cancers (Basel). 2023 Feb 18. pii: 1312. [Epub ahead of print]15(4):
    Clinical Implications of the FLT3-ITD Allelic Ratio in Acute Myeloid Leukemia in the Context of an Allogeneic Stem Cell Transplantation.
    Madlen Jentzsch, Lara Bischof, Dominic Brauer, Donata Backhaus, Jule Ussmann, Georg-Nikolaus Franke, Vladan Vucinic, Uwe Platzbecker, Sebastian Schwind.
      Although the presence of FLT3-ITD, as well as levels of the FLT3-ITD allelic ratio, have been described as prognostic factors in acute myeloid leukemia (AML), little is known about how the FLT3-ITD allelic ratio impacts patients' outcomes when receiving an allogeneic hematopoietic stem cell transplantation (HSCT). We analyzed 118 patients (median age at diagnosis 58.3, range 14.3-82.3 years) harboring FLT3-ITD, of whom 94 patients were consolidated with an allogeneic HSCT and included in outcome analyses. A high FLT3-ITD allelic ratio was associated with a higher white blood cell count, higher blood and bone marrow blasts, and worse ELN2017 risk at diagnosis. Patients with a high FLT3-ITD allelic ratio more often had NPM1 mutations, while patients with a low allelic ratio more often had FLT3-TKD mutations. Patients with a high FLT3-ITD allelic ratio were less likely to achieve a measurable residual disease (MRD)-negative remission prior to allogeneic HSCT and had a trend for a shorter time to relapse. However, there was no distinct cumulative incidence of relapse, non-relapse mortality, or overall survival according to the FLT3-ITD allelic ratio in transplanted patients. While co-mutated FLT3-TKD was associated with better outcomes, the MRD status at HSCT was the most significant factor for outcomes. While our data indicates that an allogeneic HSCT may mitigate the adverse effect of a high FLT3-ITD allelic ratio, comparative studies are needed to evaluate which FLT3-ITD mutated patients benefit from which consolidation strategy.
    Keywords:  FLT3; acute myeloid leukemia; allelic ratio; hematopoietic stem cell transplantation; prognosis
    DOI:  https://doi.org/10.3390/cancers15041312
  7. Leukemia. 2023 Feb 23.
    Nanoparticle-mediated targeting of the fusion gene RUNX1/ETO in t(8;21)-positive acute myeloid leukaemia.
    Hasan Issa, Laura E Swart, Milad Rasouli, Minoo Ashtiani, Sirintra Nakjang, Nidhi Jyotsana, Konstantin Schuschel, Michael Heuser, Helen Blair, Olaf Heidenreich.
      A hallmark of acute myeloid leukaemias (AMLs) are chromosomal rearrangements that give rise to novel leukaemia-specific fusion genes. Most of these fusion genes are both initiating and driving events in AML and therefore constitute ideal therapeutic targets but are challenging to target by conventional drug development. siRNAs are frequently used for the specific suppression of fusion gene expression but require special formulations for efficient in vivo delivery. Here we describe the use of siRNA-loaded lipid nanoparticles for the specific therapeutic targeting of the leukaemic fusion gene RUNX1/ETO. Transient knockdown of RUNX1/ETO reduces its binding to its target genes and alters the binding of RUNX1 and its co-factor CBFβ. Transcriptomic changes in vivo were associated with substantially increased median survival of a t(8;21)-AML mouse model. Importantly, transient knockdown in vivo causes long-lasting inhibition of leukaemic proliferation and clonogenicity, induction of myeloid differentiation and a markedly impaired re-engraftment potential in vivo. These data strongly suggest that temporary inhibition of RUNX1/ETO results in long-term restriction of leukaemic self-renewal. Our results provide proof for the feasibility of targeting RUNX1/ETO in a pre-clinical setting and support the further development of siRNA-LNPs for the treatment of fusion gene-driven malignancies.
    DOI:  https://doi.org/10.1038/s41375-023-01854-8
  8. Blood Rev. 2023 Feb 12. pii: S0268-960X(23)00017-6. [Epub ahead of print] 101056
    Why do we not have more drugs approved for MDS? A critical viewpoint on novel drug development in MDS.
    Stacey M Frumm, Shai Shimony, Richard M Stone, Daniel J DeAngelo, Jan Phillipp Bewersdorf, Amer M Zeidan, Maximilian Stahl.
      Approval of new agents to treat higher risk (HR) myelodysplastic syndrome (MDS) has stalled since the approval of DNA methyltransferase inhibitors (DNMTi). In addition, the options for patients with lower risk (LR) MDS who have high transfusion needs and do not harbor ring sideroblasts or 5q- syndrome are limited. Here, we review the current treatment landscape in MDS and identify areas of unmet need, such as treatment after failure of erythropoiesis-stimulating agents or DNMTis, TP53-mutated disease, and MDS with potentially targetable mutations. We discuss how our understanding of MDS pathogenesis can inform therapy development, including treating HR-MDS similarly to AML and pursuing therapies to address splicing factor mutations and dysregulated inflammation. We then bring a critical lens to current methodology of MDS studies and propose solutions to improve the efficiency and yield of these clinical trials, including using the most meaningful response metrics and expanding enrollment.
    Keywords:  Clinical trial design; DNA methyltransferase inhibitor; Myelodysplastic syndrome; Splicing factor mutation; TP53 mutation
    DOI:  https://doi.org/10.1016/j.blre.2023.101056
  9. Neoplasma. 2023 Feb 23. pii: 221217N1185. [Epub ahead of print]
    Synergistic activity and mechanism of cytarabine and MCL-1 inhibitor AZD5991 against acute myeloid leukemia.
    Yue Wang, Deying Wang, Yao Wang, Haotian Yang, Guan Wang, Shuangshuang Wu.
      The 5-year overall survival rate of acute myeloid leukemia (AML) is less than 30%. Improving clinical outcomes is still a clinical challenge for AML treatment. Simultaneous use of chemotherapeutic drugs and targeting of apoptosis pathways has become a first-line clinical treatment for AML. Myeloid cell leukemia 1 (MCL-1) is a candidate target for AML treatment. In this study, we demonstrated that inhibition of the anti-apoptotic protein MCL-1 by AZD5991 synergistic increased chemotherapeutic agent cytarabine (Ara-C)-induced apoptosis in AML cell lines and primary patient samples. Apoptosis induced by a combination of Ara-C and AZD5991 was partially dependent on caspase activity and Bak/Bax. The downregulation of MCL-1 by Ara-C and the enhancement of Ara-C-induced DNA damage through inhibition of MCL-1 are potential mechanisms underlying the synergistic anti-AML activity between Ara-C and AZD5991. Our data support the application of MCL-1 inhibitor in combination with the conventional chemotherapeutic agent for the clinical treatment of AML.
    DOI:  https://doi.org/10.4149/neo_2023_221217N1185
  10. Bone Marrow Transplant. 2023 Feb 23.
    Allogeneic stem cell transplantation for patients with acute myeloid leukemia (AML) in second complete remission (CR2) transplanted from unrelated donors with post-transplant cyclophosphamide (PTCy). A study on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation.
    Arnon Nagler, Myriam Labopin, Ryszard Swoboda, Alexander Kulagin, Hélène Labussière-Wallet, Montserrat Rovira, Didier Blaise, Jan Vydra, Ibrahim Yakoub-Agha, Goda Choi, Péter Reményi, Yener Koc, Jaime Sanz, Fabio Ciceri, Mohamad Mohty.
      Post-transplant cyclophosphamide (PTCy) is being increasingly used as graft-versus-host disease (GVHD) prophylaxis post allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with acute myeloid leukemia (AML) transplanted in first complete remission (CR1). However, results may differ in patients transplanted in CR2. We retrospectively evaluated transplant outcomes of adult AML patients transplanted between 2010-2019 from 9-10/10 human leukocyte antigen (HLA)-matched unrelated donor (UD) in CR2. In total, 127 patients were included (median age 45.5 years, 54% male). Median follow-up was 19.2 months. Conditioning was myeloablative (MAC) in 50.4% and the graft source was peripheral blood in 93.7% of the transplants. Incidence of acute (a)GVHD II-IV and III-IV was 26.2% and 9.2%. Two-year total and extensive chronic (c)GVHD were 34.3% and 13.8 %, respectively. Two-year non-relapse mortality (NRM), relapse incidence (RI), leukemia-free survival (LFS), overall survival (OS), and GVHD-free, relapse-free survival (GRFS) were 17.2%, 21.1%, 61.7, %, 65.2%, and 49.3%, respectively. Time from diagnosis to transplant (>18 months) was a favorable prognostic factor for RI, LFS, OS, and GRFS while favorable risk cytogenetics was a positive prognostic factor for OS. The patient's age was a poor prognostic factor for NRM and cGVHD. Finally, the female-to-male combination and reduced intensity conditioning (RIC) were poor and favorable prognostic factors for cGVHD, respectively. We conclude that PTCy is an effective method for GVHD prophylaxis in AML patients undergoing allo-HCT in CR2 from UD.
    DOI:  https://doi.org/10.1038/s41409-023-01940-6
  11. Leukemia. 2023 Feb 18.
    Survival of TP53-mutated acute myeloid leukemia patients receiving allogeneic stem cell transplantation after first induction or salvage therapy: results from the Consortium on Myeloid Malignancies and Neoplastic Diseases (COMMAND).
    Talha Badar, Ehab Atallah, Rory Shallis, Antoine N Saliba, Anand Patel, Jan P Bewersdorf, Justin Grenet, Maximilian Stahl, Adam Duvall, Madelyn Burkart, Neil Palmisiano, Danielle Bradshaw, Michal Kubiak, Shira Dinner, Aaron D Goldberg, Yasmin Abaza, Guru Subramanian Guru Murthy, Vamsi Kota, Mark R Litzow.
      We conducted a multi-center study to analyze factors predicting survival among patients with TP53-mutated (m) AML receiving allogeneic hematopoietic stem cell transplant (allo-HSCT) in the recent era. Out of 370 TP53m AML patients, 68 (18%) patients were bridged to allo-HSCT. The median age of the patients was 63 years (range, 33-75), 82% of patients had complex cytogenetics and 66% of patients had multi-hit TP53m. Forty three percent received myeloablative conditioning and 57% received reduced intensity conditioning. The incidence of acute graft versus host disease (GVHD) was 37% and chronic GVHD was 44%. The median event-free survival (EFS) from the time of allo-HSCT was 12.4 months (95% CI: 6.24-18.55) and median overall survival (OS) was 24.5 months (95% CI: 21.80-27.25). In multivariate analysis utilizing variables that showed significance in univariate analysis, complete remission at day 100 post allo-HSCT retained significance for EFS (HR: 0.24, 95% CI: 0.10-0.57, p = 0.001) and OS (HR: 0.22, 95% CI: 0.10-0.50, p ≤ 0.001). Similarly, occurrence of chronic GVHD retained significance for EFS (HR: 0.21, 95% CI: 0.09-0.46, p ≤ 0.001) and OS (HR: 0.34, 95% CI: 0.15-0.75, p = 0.007). Our report suggests that allo-HSCT offers the best opportunity to improve long-term outcome among patients with TP53m AML.
    DOI:  https://doi.org/10.1038/s41375-023-01847-7
  12. Haematologica. 2023 Feb 23.
    Impact of trisomy 19 on outcome according to genetic makeup in patients with acute myeloid leukemia.
    Sabine Kayser, David Martínez-Cuadrón, Rebeca Rodriguez-Veiga, Mathias Hänel, Mar Tormo, Kerstin Schäfer-Eckart, Carmen Botella, Friedrich Stölzel, Teresa Bernal Del Castillo, Ulrich Keller, Carlos Rodriguez-Medina, Gerhard Held, Maria-Luz Amigo, Christoph Schliemann, Mercedes Colorado, Martin Kaufmann, Manuel Barrios Garcia, Stefan W Krause, Martin Görner, Edgar Jost, Björn Steffen, Sven Zukunft, Uwe Platzbecker, Anthony D Ho, Claudia D Baldus, Hubert Serve, Carsten Müller-Tidow, Christian Thiede, Martin Bornhäuser, Pau Montesinos, Christoph Röllig, Richard F Schlenk.
      We retrospectively studied 97 AML patients with trisomy 19 (tris-19; median age at diagnosis 57 years; range, 17-83 years) treated between 2001 and 2019 within two multicenter study groups. Tris-19 occurred solely in 10 (10.5%), with additional abnormalities in non-complex karyotypes in 8 (8%) and within complex karyotypes in 79 (82%) patients. Altogether, karyotypes characterized by trisomies only were present in 27 (28%) patients. Data on response and outcome of intensively treated patients were available in 92 patients and median follow-up was 6.4 years (95%-CI, 2.9-9.0 years). Complete remission (CR) after induction therapy was achieved in 52% (n=48) and early death rate was 10% (n=9). Notably, patients with tris-19 as sole abnormality had a CR rate of 89%. An allogeneic hematopoietic stem cell transplantation (allo-HCT) was performed in 34 (35%) patients (CR, n=19; active disease, n=15). Five-year relapse-free and overall survival (OS) rates were 26% (95%-CI, 16-43%) and 20% (95%-CI, 13-31%), respectively. OS rates were significantly higher in patients with tris-19 as sole abnormality or within karyotypes characterized by trisomies only (P=0.05). An Andersen-Gill model including allo-HCT as a time dependent covariable on OS revealed tris-19 as sole abnormality or within karyotypes characterized by trisomies only as favorable factors (HR, 0.47; P=0.021); higher age at diagnosis had an adverse impact (10 years difference; HR, 1.29; P=0.002), whereas allo-HCT had no beneficial impact (OR, 1.45; P=0.21). In our cohort, patients with tris-19 as sole abnormality or within karyotypes characterized by trisomies only had a high CR rate and better clinical outcome.
    DOI:  https://doi.org/10.3324/haematol.2022.282127
  13. Leukemia. 2023 Feb 22.
    Human gene-engineered calreticulin mutant stem cells recapitulate MPN hallmarks and identify targetable vulnerabilities.
    Johannes Foßelteder, Gabriel Pabst, Tommaso Sconocchia, Angelika Schlacher, Lisa Auinger, Karl Kashofer, Christine Beham-Schmid, Slave Trajanoski, Claudia Waskow, Wolfgang Schöll, Heinz Sill, Armin Zebisch, Albert Wölfler, Daniel Thomas, Andreas Reinisch.
      Calreticulin (CALR) mutations present the main oncogenic drivers in JAK2 wildtype (WT) myeloproliferative neoplasms (MPN), including essential thrombocythemia and myelofibrosis, where mutant (MUT) CALR is increasingly recognized as a suitable mutation-specific drug target. However, our current understanding of its mechanism-of-action is derived from mouse models or immortalized cell lines, where cross-species differences, ectopic over-expression and lack of disease penetrance are hampering translational research. Here, we describe the first human gene-engineered model of CALR MUT MPN using a CRISPR/Cas9 and adeno-associated viral vector-mediated knock-in strategy in primary human hematopoietic stem and progenitor cells (HSPCs) to establish a reproducible and trackable phenotype in vitro and in xenografted mice. Our humanized model recapitulates many disease hallmarks: thrombopoietin-independent megakaryopoiesis, myeloid-lineage skewing, splenomegaly, bone marrow fibrosis, and expansion of megakaryocyte-primed CD41+ progenitors. Strikingly, introduction of CALR mutations enforced early reprogramming of human HSPCs and the induction of an endoplasmic reticulum stress response. The observed compensatory upregulation of chaperones revealed novel mutation-specific vulnerabilities with preferential sensitivity of CALR mutant cells to inhibition of the BiP chaperone and the proteasome. Overall, our humanized model improves purely murine models and provides a readily usable basis for testing of novel therapeutic strategies in a human setting.
    DOI:  https://doi.org/10.1038/s41375-023-01848-6
  14. Blood Adv. 2023 Feb 21. pii: bloodadvances.2022007956. [Epub ahead of print]
    TAK-981, a SUMOylation inhibitor, suppresses AML growth immune-independently.
    Han Sun Kim, Bo-Reum Kim, Thien T P Dao, Jin-Mo Kim, Yoon-Joo Kim, Hyunsong Son, Sihyang Jo, Doyeon Kim, Jiwoo Kim, Young Ju Suh, Hee Je Kim, Byung-Sik Cho, Sunghyouk Park.
      Acute myeloid leukemia (AML) generally has an unsatisfactory prognosis despite recent introduction of new regimens including targeted agents and antibodies. To find a new druggable pathway, we performed integrated bioinformatic pathway screening on large OHSU and MILE AML databases, discovered the SUMOylation pathway, and validated it independently with an external dataset (totaling 2959 AML and 642 normal sample data). The clinical relevance of SUMOylation in AML was supported by its core gene expression which is correlated with patient survival, ELN2017 risk classification, and AML-relevant mutations. TAK-981, a first-in-class SUMOylation inhibitor currently under clinical trials for solid tumors, showed anti-leukemic effects with apoptosis induction, cell-cycle arrest and induction of differentiation marker expression in leukemic cells. It exhibited potent nanomolar activity, often stronger than that of cytarabine, which is part of the standard-of-care. TAK-981's utility was further demonstrated in in vivo mouse and human leukemia models as well as patient-derived primary AML cells. Our results also indicate direct and cancer-cell-inherent anti-AML effects by TAK-981, different from the IFN1 and immune-dependent mechanism in a previous solid tumor study. Overall, we provide a proof-of-concept for SUMOylation as a new targetable pathway in AML and propose TAK-981 as a promising direct anti-AML agent. Our data should prompt studies on optimal combination strategies and transitions to clinical trials in AML.
    DOI:  https://doi.org/10.1182/bloodadvances.2022007956
  15. Mol Cell Proteomics. 2023 Feb 17. pii: S1535-9476(23)00027-0. [Epub ahead of print] 100517
    Proteomic characterization of acute myeloid leukemia for precision medicine.
    Pedro Casado, Pedro R Cutillas.
      Acute myeloid leukemia (AML) is a highly heterogeneous cancer of the hematopoietic system with no cure for most patients. In addition to chemotherapy, treatment options for AML include recently approved therapies that target proteins with roles in AML pathobiology, such as FLT3, BLC2 and IDH1/2. However, due to disease complexity, these therapies produce very diverse responses, and survival rates are still low. Thus, despite considerable advances, there remains a need for therapies that target different aspects of leukemic biology, and for associated biomarkers that define patient populations likely to respond to each available therapy. To meet this need, drugs that target different AML vulnerabilities are currently in advanced stages of clinical development. Here, we review proteomics and phosphoproteomics studies that aimed to provide insights into AML biology and clinical disease heterogeneity not attainable with genomic approaches. To place the discussion in context, we first provide an overview of genetic and clinical aspects of the disease, followed by a summary of proteins targeted by compounds that have been approved or are under clinical trials for AML treatment and, if available, the biomarkers that predict responses. We then discuss proteomics and phosphoproteomics studies that provided insights into AML pathogenesis, from which potential biomarkers and drug targets were identified, and studies that aimed to rationalize the use of synergistic drug combinations. When considered as a whole, the evidence summarized here suggests that proteomics and phosphoproteomics approaches can play a crucial role in the development and implementation of precision medicine for AML patients.
    DOI:  https://doi.org/10.1016/j.mcpro.2023.100517
  16. Am J Hematol. 2023 Feb 22.
    Phenotypic Characterization of Disease-Initiating Stem Cells in JAK2- or CALR-mutated Myeloproliferative Neoplasms.
    Daniel Ivanov, Jelena D Milosevic Feenstra, Irina Sadovnik, Harald Herrmann, Barbara Peter, Michael Willmann, Georg Greiner, Katharina Slavnitsch, Emir Hadzijusufovic, Thomas Rülicke, Maik Dahlhoff, Gregor Hoermann, Sigrid Machherndl-Spandl, Gregor Eisenwort, Michael Fillitz, Thamer Sliwa, Maria-Theresa Krauth, Peter Bettelheim, Wolfgang R Sperr, Elisabeth Koller, Michael Pfeilstöcker, Heinz Gisslinger, Felix Keil, Robert Kralovics, Peter Valent.
      Myeloproliferative neoplasms (MPN) are characterized by uncontrolled expansion of myeloid cells, disease-related mutations in certain driver-genes including JAK2, CALR and MPL, and a substantial risk to progress to secondary acute myeloid leukemia (sAML). Although behaving as stem cell neoplasms, little is known about disease-initiating stem cells in MPN. We established the phenotype of putative CD34+ /CD38- stem cells and CD34+ /CD38+ progenitor cells. A total of 111 patients with MPN suffering from polycythemia vera, essential thrombocythemia, or primary myelofibrosis (PMF) were examined. In almost all patients tested, CD34+ /CD38- stem cells expressed CD33, CD44, CD47, CD52, CD97, CD99, CD105, CD117, CD123, CD133, CD184, CD243, and CD274 (PD-L1). In patients with PMF, MPN stem cells often expressed CD25 and sometimes also CD26 in an aberrant manner. MPN stem cells did not exhibit substantial amounts of CD90, CD273 (PD-L2), CD279 (PD-1), CD366 (TIM-3), CD371 (CLL-1), or IL-1RAP. The phenotype of CD34+ /CD38- stem cells did not change profoundly during progression from MPN to sAML. The disease-initiating capacity of putative MPN stem cells was confirmed in NSGS mice. Whereas CD34+ /CD38- MPN cells engrafted in NSGS mice, no substantial engraftment was produced by CD34+ /CD38+ or CD34- cells. The JAK2-targeting drug fedratinib and the BRD4 degrader dBET6 induced apoptosis and suppressed proliferation in MPN stem cells. Together, MPN stem cells display a unique phenotype, including cytokine receptors, immune checkpoint molecules and other clinically relevant target antigens. Phenotypic characterization of neoplastic stem cells in MPN and sAML should facilitate their enrichment and the development of better, stem cell-eradicating (curative), therapies. This article is protected by copyright. All rights reserved.
    DOI:  https://doi.org/10.1002/ajh.26889
  17. Haematologica. 2023 Feb 23.
    Comprehensive molecular and clinical characterization of NUP98 fusions in pediatric acute myeloid leukemia.
    Eline J M Bertrums, Jenny L Smith, Lauren Harmon, Rhonda E Ries, Yi-Cheng J Wang, Todd A Alonzo, Andrew J Menssen, Karen M Chisholm, Amanda R Leonti, Katherine Tarlock, Fabiana Ostronoff, Era L Pogosova-Agadjanyan, Gertjan J L Kaspers, Henrik Hasle, Michael Dworzak, Christiane Walter, Nora Muhlegger, Cristina Morerio, Laura Pardo, Betsy Hirsch, Susana Raimondi, Todd M Cooper, Richard Aplenc, Alan S Gamis, Edward A Kolb, Jason E Farrar, Derek Stirewalt, Xiaotu Ma, Tim I Shaw, Scott N Furlan, Lisa Eidenschink Brodersen, Michael R Loken, Marry M Van den Heuvel-Eibrink, C Michel Zwaan, Timothy J Triche, Bianca F Goemans, Soheil Meshinchi.
      NUP98 fusions c omprise a family o f rare r ecurrent a lterations i n A ML, associated w ith adverse outcomes. To define the underlying biology and clinical implications of this family of fusions, we performed comprehensive transcriptome, epigenome, and immunophenotypic profiling of 2,235 children and young adults with AML and identified 160 NUP98 rearrangements (7.2%), including 108 NUP98-NSD1 (4.8%), 32 NUP98-KDM5A (1.4%) and 20 NUP98-X cases (0.9%) with 13 different fusion partners. Fusion partners defined disease characteristics and biology; patients with NUP98-NSD1 or NUP98-KDM5A had distinct immunophenotypic, transcriptomic, and epigenomic profiles. Unlike the two most prevalent NUP98 fusions, NUP98-X variants are typically not cryptic. Furthermore, NUP98-X cases are associated with WT1 mutations, and have epigenomic profiles that resemble either NUP98- NSD1 or NUP98-KDM5A. Cooperating FLT3-ITD and WT1 mutations define NUP98-NSD1, and chromosome 13 aberrations are highly enriched in NUP98-KDM5A. Importantly, we demonstrate that NUP98 fusions portend dismal overall survival, with the noteworthy exception of patients bearing abnormal chr13.
    DOI:  https://doi.org/10.3324/haematol.2022.281653
  18. EJHaem. 2023 Feb;4(1): 165-173
    Efficacy analysis of different FLT3 inhibitors in patients with relapsed/refractory acute myeloid leukemia and high-risk myelodysplastic syndrome.
    Mahesh Swaminathan, Mai M Aly, Abdul Moiz Khan, Bayan Al Share, Vikram Dhillon, Enxhi Lalo, Harry Ramos, Katherine G Akers, Seongho Kim, Suresh Balasubramanian.
      Several FLT3 inhibitors(i) are available to treat relapsed/refractory (R/R) FLT3-internal tandem duplicated acute myeloid leukemia (AML). This study analyzes the efficacies of various FLT3i (types 1 and 2) tested in clinical trials in treating R/R AML and high-risk myelodysplastic syndromes (HR-MDS). PubMed and EMBASE databases were searched for single/double-arm phase I/II/III R/R AML or HR-MDS clinical trials published between 1/1/2000 and 6/1/2021. The outcomes studied were composite response rate (CRc) and overall response rate (ORR). Toxicities were compared based on the organ system. The 28 studies analyzed had 1927 patients. The pooled ORR and (CRc) for all FLT3i were 53% (95% CI, 43%-63%) and 34% (95% CI, 26%-44%). Pooled ORR and CRc were 37% (95% CI, 25%-51%) and 35% (95% CI, 21%-52%) for type 1 and 58% (95% CI, 43%-71%) and 38% (95% CI, 27%-50%) for type 2, respectively. Gastrointestinal (GI) and hematological toxicity occurred in 22% (95% CI, 19%-25.4%) and 74.6% (95% CI, 70%-79%) with type 1 and 13.9% (95% CI, 12%-16%) and 57.7% (95% CI, 54.6%-60.8%) with type 2 FLT3i. QTc prolongation occurred in 2.06% (95% CI, 1.03%-3.65%) with type 1 and 7% (95% CI, 5.3%-9%) with type 2 FLT3i. Type 2 FLT3i had less GI toxicity but more QTc prolongation. Prospective studies are needed to compare the efficacy of type 1 and 2 FLT3i.
    Keywords:  FLT3 inhibitors; meta‐analysis; relapsed/refractory acute myeloid leukemia; type 1; type 2
    DOI:  https://doi.org/10.1002/jha2.616
  19. Leukemia. 2023 Feb 22.
    MDS subclassification-do we still have to count blasts?
    Sandra Huber, Torsten Haferlach, Heiko Müller, Manja Meggendorfer, Stephan Hutter, Gregor Hoermann, Constance Baer, Wolfgang Kern, Claudia Haferlach.
      
    DOI:  https://doi.org/10.1038/s41375-023-01855-7
  20. Cell Stem Cell. 2023 Feb 14. pii: S1934-5909(23)00008-5. [Epub ahead of print]
    Reversal of malignant ADAR1 splice isoform switching with Rebecsinib.
    Leslie A Crews, Wenxue Ma, Luisa Ladel, Jessica Pham, Larisa Balaian, S Kathleen Steel, Phoebe K Mondala, Raymond H Diep, Christina N Wu, Cayla N Mason, Inge van der Werf, Isabelle Oliver, Eduardo Reynoso, Gabriel Pineda, Thomas C Whisenant, Peggy Wentworth, James J La Clair, Qingfei Jiang, Michael D Burkart, Catriona H M Jamieson.
      Adenosine deaminase acting on RNA1 (ADAR1) preserves genomic integrity by preventing retroviral integration and retrotransposition during stress responses. However, inflammatory-microenvironment-induced ADAR1p110 to p150 splice isoform switching drives cancer stem cell (CSC) generation and therapeutic resistance in 20 malignancies. Previously, predicting and preventing ADAR1p150-mediated malignant RNA editing represented a significant challenge. Thus, we developed lentiviral ADAR1 and splicing reporters for non-invasive detection of splicing-mediated ADAR1 adenosine-to-inosine (A-to-I) RNA editing activation; a quantitative ADAR1p150 intracellular flow cytometric assay; a selective small-molecule inhibitor of splicing-mediated ADAR1 activation, Rebecsinib, which inhibits leukemia stem cell (LSC) self-renewal and prolongs humanized LSC mouse model survival at doses that spare normal hematopoietic stem and progenitor cells (HSPCs); and pre-IND studies showing favorable Rebecsinib toxicokinetic and pharmacodynamic (TK/PD) properties. Together, these results lay the foundation for developing Rebecsinib as a clinical ADAR1p150 antagonist aimed at obviating malignant microenvironment-driven LSC generation.
    Keywords:  ADAR1; RNA editing; cancer stem cells; cancer therapy; hematopoiesis; leukemia stem cells; myelofibrosis; myeloproliferative neoplasms; secondary AML; splicing
    DOI:  https://doi.org/10.1016/j.stem.2023.01.008
  21. Leukemia. 2023 Feb 18.
    High expression of an intragenic long noncoding RNA misinterpreted as high FTO oncogene expression in NPM1 mutant acute myeloid leukemia.
    Saioa Arza-Apalategi, Branco M H Heuts, Meike T M Dooijes, Daan Gilissen, Adrian J P van der Heijden, Joop H Jansen, Joost H A Martens, Bert A van der Reijden.
      
    DOI:  https://doi.org/10.1038/s41375-023-01844-w
  22. Clin Lymphoma Myeloma Leuk. 2023 Jan 16. pii: S2152-2650(23)00020-4. [Epub ahead of print]
    Sex Disparities in Myelodysplastic Syndromes: Genotype, Phenotype, and Outcomes.
    Sara M Tinsley-Vance, Najla Al Ali, Somedeb Ball, Luis E Aguirre, Akriti G Jain, Mohammad Omar Hussaini, Onyee Chan, Andrew Kuykendall, Kendra Sweet, Jeffrey Lancet, Eric Padron, David A Sallman, Rami S Komrokji.
      Introduction/Background The impact of biological sex on the clinical phenotype, genotype, and outcomes among patients with MDS is not well characterized. Materials and Methods We retrospectively reviewed the clinical and genomic data from male and female patients included in our institutional MDS database at Moffitt Cancer Center. Results Among 4580 patients with MDS, 2922 (66%) were men and 1658 (34%) were women. Women were younger (mean age 66.5 vs. 69 years for men, P < .001) at diagnosis. There were more Hispanic/black women than men (9% vs. 5%, P =<.001). Women had lower hemoglobin and higher platelet counts than men. More women had del 5q/monosomy 5 abnormalities compared to men (P =<.001). Therapy related MDS were more common in women than men (25% vs.17%, P=<.001). On assessment of molecular profile, SRSF2, U2AF1, ASXL1, and RUNX1 mutations were more frequent in men. The median overall survival (mOS) was 37.5 months (mo) for females compared to 35 monthsfor males, (P = .002). The mOS was significantly prolonged for women in lower-risk MDS, but not in higher-risk MDS. Women were more likely to respond to immunosuppression with ATG/CSA than men (38% vs. 19%, P= 0.04).Conclusion Ongoing research is needed for understanding the impact of sex on phenotype, genotype, and outcomes in patients diagnosed with MDS.
    Keywords:  sex differences, genomic data, splicing machinery mutations; somatic mutations
    DOI:  https://doi.org/10.1016/j.clml.2023.01.007
  23. Leuk Res. 2023 Feb 14. pii: S0145-2126(23)00025-5. [Epub ahead of print]127 107040
    Comparison between azacitidine and decitabine as front-line therapy in elderly acute myeloid leukemia patients not eligible for intensive chemotherapy.
    L Maurillo, A Spagnoli, A Candoni, C Papayannidis, E Borlenghi, D Lazzarotto, L Fianchi, M Sciumè, M E Zannier, F Buccisano, M I Del Principe, V Mancini, M Breccia, R Fanin, E Todisco, M Lunghi, R Palmieri, N Fracchiolla, P Musto, G Rossi, A Venditti.
      We compared the efficacy of azacitidine (AZA) and decitabine (DEC) in elderly patients with untreated AML, diagnosed according to WHO criteria. In the two groups, we evaluated complete remission (CR), overall survival (OS) and disease free survival (DFS). The AZA and DEC groups included 139 and 186 patients, respectively. To minimize the effects of treatment selection bias, adjustments were made using the propensity-score matching method, which yielded 136 patient pairs. In the AZA and DEC cohort, median age was 75 years in both, (IQR, 71-78 and 71-77), median WBCc at treatment onset 2.5 × 109/L (IQR, 1.6-5.8) and 2.9 × 109/L (IQR, 1.5-8.1), median bone marrow (BM) blast count 30% (IQR, 24-41%) and 49% (IQR, 30-67%), 59 (43%) and 63 (46%) patients had a secondary AML, respectively. Karyotype was evaluable in 115 and 120 patients: 80 (59%) and 87 (64%) had intermediate-risk, 35 (26%) and 33 (24%) an adverse risk karyotype, respectively. Median number of cycles delivered was 6 (IQR, 3.0-11.0) and 4 (IQR, 2.0-9.0), CR rate was 24% vs 29%, median OS and 2-year OS rates 11.3 (95% CI 9.5-13.8) vs 12.0 (95% CI 7.1-16.5) months and 20% vs 24%, respectively. No differences in CR and OS were found within the following subgroup: intermediate- and adverse-risk cytogenetic, frequency of WBCc at treatment ≥ 5 × 10^9 L and < 5 × 10^9/L, de novo and secondary AML, BM blast count < and ≥ 30%. Median DFS for AZA and DEC treated patients was 9.2 vs 12 months, respectively. Our analysis indicates similar outcomes with AZA compared to DEC.
    Keywords:  Acute myeloid leukemia; Azacitidine; Decitabine; Elderly; Unfit
    DOI:  https://doi.org/10.1016/j.leukres.2023.107040
  24. Sci Adv. 2023 Feb 22. 9(8): eade8222
    PI3-kinase deletion promotes myelodysplasia by dysregulating autophagy in hematopoietic stem cells.
    Kristina Ames, Imit Kaur, Yang Shi, Meng M Tong, Taneisha Sinclair, Shayda Hemmati, Shira G Glushakow-Smith, Ellen Tein, Lindsay Gurska, Ulrich Steidl, Robert Dubin, Jidong Shan, Cristina Montagna, Kith Pradhan, Amit Verma, Kira Gritsman.
      Myelodysplastic syndrome (MDS) is a clonal malignancy arising in hematopoietic stem cells (HSCs). The mechanisms of MDS initiation in HSCs are still poorly understood. The phosphatidylinositol 3-kinase (PI3K)/AKT pathway is frequently activated in acute myeloid leukemia, but in MDS, PI3K/AKT is often down-regulated. To determine whether PI3K down-regulation can perturb HSC function, we generated a triple knockout (TKO) mouse model with Pik3ca, Pik3cb, and Pik3cd deletion in hematopoietic cells. Unexpectedly, PI3K deficiency caused cytopenias, decreased survival, and multilineage dysplasia with chromosomal abnormalities, consistent with MDS initiation. TKO HSCs exhibit impaired autophagy, and pharmacologic autophagy induction improved HSC differentiation. Using intracellular LC3 and P62 flow cytometry and transmission electron microscopy, we also observed abnormal autophagic degradation in patient MDS HSCs. Therefore, we have uncovered an important protective role for PI3K in maintaining autophagic flux in HSCs to preserve the balance between self-renewal and differentiation and to prevent MDS initiation.
    DOI:  https://doi.org/10.1126/sciadv.ade8222
  25. Blood. 2023 Feb 23. pii: blood.2022018564. [Epub ahead of print]
    Stochastic fate decisions of HSCs after transplantation: early contribution, symmetric expansion, and pool formation.
    Stefan Radtke, Mark R Enstrom, Dnyanada Pande, Elizabeth R Duke, Erwing Fabian Cardozo Ojeda, Ravishankar Madhu, Staci Owen, Greta Kanestrom, Margaret Lee Cui, Anai M Perez, Joshua T Schiffer, Hans-Peter Kiem.
      Hematopoietic stem cells (HSCs) are assumed to be rare, infrequently dividing, long-lived, and not involved in immediate recovery after transplantation. Here we performed unprecedented high-density clonal tracking in nonhuman primates and found long-term persisting HSC clones to actively contribute during early neutrophil recovery and be the main source of blood production as early as 50 days post-transplant. Most surprisingly, we observed a rapid decline in the number of unique HSC clones, while persisting HSCs expanded undergoing symmetric divisions to create identical siblings and formed clonal pools ex vivo as well as in vivo. In contrast to the currently assumed model of hematopoietic reconstitution, we provide evidence for contribution of HSCs in short-term recovery as well as symmetric expansion of individual clones into pools. These findings provide novel insights into HSC biology informing the design of HSC transplantation and gene therapy studies.
    DOI:  https://doi.org/10.1182/blood.2022018564
  26. Blood Adv. 2023 Feb 21. pii: bloodadvances.2023009668. [Epub ahead of print]
    Physioxia improves the selectivity of hematopoietic stem cell expansion cultures.
    Kyomi J Igarashi, Iwo Kucinski, Yan Yi Chan, Tze-Kai Tan, Hwei Minn Khoo, David Kealy, Joydeep Bhadury, Ian Hsu, Pui Yan Ho, Kouta Niizuma, John W Hickey, Garry Nolan, Katherine S Bridge, Agnieszka Czechowicz, Berthold Gottgens, Hiromitsu Nakauchi, Adam C Wilkinson.
      Hematopoietic stem cells (HSCs) are a rare hematopoietic cell type that can entirely reconstitute the blood and immune systems following transplantation. Allogeneic HSC transplantation (HSCT) is used clinically as a curative therapy for a range of hematolymphoid diseases, but remains a high-risk therapy due to potential side effects including poor graft function and graft-vs-host disease (GvHD). Ex vivo HSC expansion has been suggested as an approach to improve hematopoietic reconstitution from low-cell dose grafts. Here, we demonstrate that we can improve the selectivity of polyvinyl alcohol (PVA)-based mouse HSC cultures through the use of physioxic culture conditions. Single-cell transcriptomic analysis confirmed inhibition of lineage-committed progenitor cells in physioxic cultures. Long-term physioxic expansion also afforded culture-based ex vivo HSC selection from whole bone marrow, spleen, and embryonic tissues. Furthermore, we provide evidence that HSC-selective ex vivo cultures deplete GvHD-causing T cells and that this approach can be combined with genotoxic-free antibody-based conditioning HSCT approaches. Our results offer a simple approach to improve PVA-based HSC cultures and the underlying molecular phenotype, as well as highlight the potential translational implications of selective HSC expansion systems for allogeneic HSCT.
    DOI:  https://doi.org/10.1182/bloodadvances.2023009668
  27. EJHaem. 2023 Feb;4(1): 153-164
    GSK3 inhibitor enhances gemtuzumab ozogamicin-induced apoptosis in primary human leukemia cells by overcoming multiple mechanisms of resistance.
    Aki Inase, Yimamu Maimaitili, Shiro Kimbara, Yu Mizutani, Yoshiharu Miyata, Shinya Ohata, Hisayuki Matsumoto, Akihito Kitao, Rina Sakai, Koji Kawaguchi, Ako Higashime, Shigeki Nagao, Keiji Kurata, Hideaki Goto, Shinichiro Kawamoto, Kimikazu Yakushijin, Hironobu Minami, Hiroshi Matsuoka.
      In acute myeloid leukemia (AML), the heterogeneity of genetic and epigenetic characteristics makes treatment difficult. The prognosis for AML is therefore poor, and there is an urgent need for new treatments for this condition. Gemtuzumab ozogamicin (GO), the first antibody-drug conjugate (ADC), targets the CD33 antigen expressed in over 90% of AML cases. GO therefore has the potential to counter the heterogeneity of AML patients. However, a major clinical problem is that drug resistance to GO diminishes its effect over time. Here, we report that the inhibition of glycogen synthase kinase 3 (GSK3) alone overcomes several forms of GO resistance at concentrations without antileukemic effects. The GSK3 inhibitors tested significantly enhanced the cytotoxic effect of GO in AML cell lines. We elucidated four mechanisms of enhancement: (1) increased expression of CD33, the target antigen of GO; (2) activation of a lysosomal function essential for hydrolysis of the GO linker; (3) reduced expression of MDR1 that eliminates calicheamicin, the payload of GO; and (4) reduced expression of the anti-apoptotic factor Bcl-2. A similar combination effect was observed against patient-derived primary AML cells. Combining GO with GSK3 inhibitors may be efficacious in treating heterogeneous AML.
    Keywords:  AML; GSK3 inhibitor; gemtuzumab ozogamicin; overcome resistance
    DOI:  https://doi.org/10.1002/jha2.600
  28. Cell. 2023 Feb 16. pii: S0092-8674(23)00050-8. [Epub ahead of print]186(4): 732-747.e16
    Human hematopoietic stem cell vulnerability to ferroptosis.
    Jiawei Zhao, Yuemeng Jia, Dilnar Mahmut, Amy A Deik, Sarah Jeanfavre, Clary B Clish, Vijay G Sankaran.
      Hematopoietic stem cells (HSCs) have a number of unique physiologic adaptations that enable lifelong maintenance of blood cell production, including a highly regulated rate of protein synthesis. Yet, the precise vulnerabilities that arise from such adaptations have not been fully characterized. Here, inspired by a bone marrow failure disorder due to the loss of the histone deubiquitinase MYSM1, characterized by selectively disadvantaged HSCs, we show how reduced protein synthesis in HSCs results in increased ferroptosis. HSC maintenance can be fully rescued by blocking ferroptosis, despite no alteration in protein synthesis rates. Importantly, this selective vulnerability to ferroptosis not only underlies HSC loss in MYSM1 deficiency but also characterizes a broader liability of human HSCs. Increasing protein synthesis rates via MYSM1 overexpression makes HSCs less susceptible to ferroptosis, more broadly illustrating the selective vulnerabilities that arise in somatic stem cell populations as a result of physiologic adaptations.
    Keywords:  ferroptosis; genetic disorder; hematopoiesis; hematopoietic stem cell; ribosome profiling; translation
    DOI:  https://doi.org/10.1016/j.cell.2023.01.020
  29. Nature. 2023 Feb 22.
    Chemically defined cytokine-free expansion of human haematopoietic stem cells.
    Masatoshi Sakurai, Kantaro Ishitsuka, Ryoji Ito, Adam C Wilkinson, Takaharu Kimura, Eiji Mizutani, Hidekazu Nishikii, Kazuhiro Sudo, Hans Jiro Becker, Hiroshi Takemoto, Tsubasa Sano, Keisuke Kataoka, Satoshi Takahashi, Yukio Nakamura, David G Kent, Atsushi Iwama, Shigeru Chiba, Shinichiro Okamoto, Hiromitsu Nakauchi, Satoshi Yamazaki.
      Haematopoietic stem cells (HSCs) are a rare cell type that reconstitute the entire blood and immune systems after transplantation and can be used as a curative cell therapy for a variety of haematological diseases1,2. However, the low number of HSCs in the body makes both biological analyses and clinical application difficult, and the limited extent to which human HSCs can be expanded ex vivo remains a substantial barrier to the wider and safer therapeutic use of HSC transplantation3. Although various reagents have been tested in attempts to stimulate the expansion of human HSCs, cytokines have long been thought to be essential for supporting HSCs ex vivo4. Here we report the establishment of a culture system that allows the long-term ex vivo expansion of human HSCs, achieved through the complete replacement of exogenous cytokines and albumin with chemical agonists and a caprolactam-based polymer. A phosphoinositide 3-kinase activator, in combination with a thrombopoietin-receptor agonist and the pyrimidoindole derivative UM171, were sufficient to stimulate the expansion of umbilical cord blood HSCs that are capable of serial engraftment in xenotransplantation assays. Ex vivo HSC expansion was further supported by split-clone transplantation assays and single-cell RNA-sequencing analysis. Our chemically defined expansion culture system will help to advance clinical HSC therapies.
    DOI:  https://doi.org/10.1038/s41586-023-05739-9
  30. Nat Immunol. 2023 Feb 23.
    CD40 signal rewires fatty acid and glutamine metabolism for stimulating macrophage anti-tumorigenic functions.
    Pu-Ste Liu, Yi-Ting Chen, Xiaoyun Li, Pei-Chun Hsueh, Sheue-Fen Tzeng, Hsi Chen, Pei-Zhu Shi, Xin Xie, Sweta Parik, Mélanie Planque, Sarah-Maria Fendt, Ping-Chih Ho.
      Exposure of lipopolysaccharide triggers macrophage pro-inflammatory polarization accompanied by metabolic reprogramming, characterized by elevated aerobic glycolysis and a broken tricarboxylic acid cycle. However, in contrast to lipopolysaccharide, CD40 signal is able to drive pro-inflammatory and anti-tumorigenic polarization by some yet undefined metabolic programming. Here we show that CD40 activation triggers fatty acid oxidation (FAO) and glutamine metabolism to promote ATP citrate lyase-dependent epigenetic reprogramming of pro-inflammatory genes and anti-tumorigenic phenotypes in macrophages. Mechanistically, glutamine usage reinforces FAO-induced pro-inflammatory and anti-tumorigenic activation by fine-tuning the NAD+/NADH ratio via glutamine-to-lactate conversion. Genetic ablation of important metabolic enzymes involved in CD40-mediated metabolic reprogramming abolishes agonistic anti-CD40-induced antitumor responses and reeducation of tumor-associated macrophages. Together these data show that metabolic reprogramming, which includes FAO and glutamine metabolism, controls the activation of pro-inflammatory and anti-tumorigenic polarization, and highlight a therapeutic potential of metabolic preconditioning of tumor-associated macrophages before agonistic anti-CD40 treatments.
    DOI:  https://doi.org/10.1038/s41590-023-01430-3
  31. Nat Chem Biol. 2023 Feb 23.
    Depletion of creatine phosphagen energetics with a covalent creatine kinase inhibitor.
    Narek Darabedian, Wenzhi Ji, Mengyang Fan, Shan Lin, Hyuk-Soo Seo, Ekaterina V Vinogradova, Tomer M Yaron, Evanna L Mills, Haopeng Xiao, Kristine Senkane, Emily M Huntsman, Jared L Johnson, Jianwei Che, Lewis C Cantley, Benjamin F Cravatt, Sirano Dhe-Paganon, Kimberly Stegmaier, Tinghu Zhang, Nathanael S Gray, Edward T Chouchani.
      Creatine kinases (CKs) provide local ATP production in periods of elevated energetic demand, such as during rapid anabolism and growth. Thus, creatine energetics has emerged as a major metabolic liability in many rapidly proliferating cancers. Whether CKs can be targeted therapeutically is unknown because no potent or selective CK inhibitors have been developed. Here we leverage an active site cysteine present in all CK isoforms to develop a selective covalent inhibitor of creatine phosphagen energetics, CKi. Using deep chemoproteomics, we discover that CKi selectively engages the active site cysteine of CKs in cells. A co-crystal structure of CKi with creatine kinase B indicates active site inhibition that prevents bidirectional phosphotransfer. In cells, CKi and its analogs rapidly and selectively deplete creatine phosphate, and drive toxicity selectively in CK-dependent acute myeloid leukemia. Finally, we use CKi to uncover an essential role for CKs in the regulation of proinflammatory cytokine production in macrophages.
    DOI:  https://doi.org/10.1038/s41589-023-01273-x
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