bims-tremyl 2024-01-14 papers

bims-tremyl

Biomed News

on Therapy resistance biology in myeloid leukemia

Issue of 2024–01–14
thirty papers selected by
Paolo Gallipoli, Barts Cancer Institute, Queen Mary University of London

Tri-ing to decipher trisomy AML.
Droplet digital PCR for sensitive relapse detection in acute myeloid leukaemia patients transplanted by reduced intensity conditioning.
Allogeneic haematopoietic cell transplantation for therapy-related myeloid neoplasms arising following treatment for lymphoma: a retrospective study on behalf of the Chronic Malignancies Working Party of the EBMT.
Monosomy 7/del(7q) Cause Sensitivity to Inhibitors of Nicotinamide Phosphoribosyltransferase in Acute Myeloid Leukemia.
Linking GATA2 to myeloid dysplasia and complex cytogenetics in adult myelodysplastic neoplasm and acute myeloid leukemia.
KBTBD4-mediated Reduction of MYC Is Critical For Hematopoietic Stem Cell Expansion Upon UM171 Treatment.
IL-1β promotes MPN disease initiation by favoring early clonal expansion of JAK2-mutant hematopoietic stem cells.
The remission status of AML patients post alloSCT is associated with a distinct single-cell bone marrow T cell signature.
Prophylactic maintenance with venetoclax/azacitidine after reduced intensity conditioning allo-transplant for high risk MDS and AML.
Hematopoietic stem cell quiescence and DNA replication dynamics maintained by the resilient β-catenin/Hoxa9/Prmt1 axis.
The nonessential amino acid cysteine is required to prevent ferroptosis in acute myeloid leukemia.
Fludarabine, Cytarabine, Granulocyte Colony-Stimulating Factor, and Idarubicin With Gemtuzumab Ozogamicin Improves Event-Free Survival in Younger Patients With Newly Diagnosed AML and Overall Survival in Patients With NPM1 and FLT3 Mutations.
RNA-binding protein RBM5 plays an essential role in acute myeloid leukemia by activating the oncogenic protein HOXA9.
Evaluation of apoptosis stimulating protein of TP53-1 (ASPP1/PPP1R13B) to predict therapy resistance and overall survival in acute myeloid leukemia (AML).
A time- and single-cell-resolved model of murine bone marrow hematopoiesis.
Deep learning predicts therapy-relevant genetics in acute myeloid leukemia from Pappenheim-stained bone marrow smears.
Synergy and antagonism between azacitidine and FLT3 inhibitors.
First-hit SETBP1 mutations cause a myeloproliferative disorder with bone marrow fibrosis.
Risk Factors for Clonal Hematopoiesis of Indeterminate Potential in People with HIV: a report from the REPRIEVE Trial.
Isocitrate Dehydrogenase Mutations in Cancer: Mechanisms of Transformation and Metabolic Liability.
Matched unrelated donor transplantation versus haploidentical transplantation with post-transplant cyclophosphamide in children with acute myeloid leukemia: a PDWP-EBMT study.
Prevalence, Dynamics, and Prognostic Role of Clonal Hematopoiesis of Indeterminate Potential in Patients With Breast Cancer.
Prophylaxis and management of graft-versus-host disease after stem-cell transplantation for haematological malignancies: updated consensus recommendations of the European Society for Blood and Marrow Transplantation.
Real-world Effectiveness of Azacitidine in Treatment-Naive Patients With Higher-risk Myelodysplastic Syndromes.
ROCK1/2 signaling contributes to corticosteroid-refractory acute graft-versus-host disease.
Acute leukemia of ambiguous lineage with BCL11B rearrangement.
Hypoxia and intra-complex genetic suppressors rescue complex I mutants by a shared mechanism.
A new genomic framework to categorize pediatric acute myeloid leukemia.
Passenger gene co-amplifications create collateral therapeutic vulnerabilities in cancer.
A blastic plasmacytoid dendritic cell neoplasm-like immunophenotype is negatively associated with CEBPA bZIP mutation and predicts unfavorable prognosis in acute myeloid leukemia.

Br J Haematol. 2024 Jan 08.

Tri-ing to decipher trisomy AML.

Shai Shimony, Evan C Chen.

  Lam et al. compared trisomy acute myeloid leukaemia (AML) patients (inclusive of single trisomy, double trisomy or tetrasomy cases) with cytogenetically normal AML to uncover distinguishing molecular and prognostic features of trisomy AML. The study contributes to our understanding of trisomy AML, but the heterogeneity of trisomy subtypes remains a barrier to its study. Commentary on: Lam et al. Distinct karyotypic and mutational landscape in trisomy AML. Br J Haematol 2024 (Online ahead of print). doi: 10.1111/bjh.19249.

Keywords:  cytogenetic abnormalities; myeloid neoplasms; trisomy AML

DOI:  https://doi.org/10.1111/bjh.19294
Eur J Haematol. 2024 Jan 10.

Droplet digital PCR for sensitive relapse detection in acute myeloid leukaemia patients transplanted by reduced intensity conditioning.

Jonas Kassow Gronlund, Christopher Veigaard, Caroline Juhl-Christensen, Anne-Sofie Skou, Dorte Melsvik, Hans Beier Ommen.

   INTRODUCTION: Follow-up after allogeneic transplantation in acute myeloid leukaemia (AML) is guided by measurable residual disease (MRD) testing. Quantitative polymerase chain reaction (qPCR) is the preferred MRD platform but unfortunately, 40%-60% of AML patients have no high-quality qPCR target. This study aimed to improve MRD testing by utilising droplet digital PCR (ddPCR). ddPCR offers patient-specific monitoring but concerns of tracking clonal haematopoiesis rather than malignant cells prompt further validation.
METHODS: Retrospectively, we performed MRD testing on blood and bone marrow samples from AML patients transplanted by reduced-intensity conditioning.
RESULTS: The applicability of ddPCR was 39/42 (92.9%). Forty-five ddPCR assays were validated with a 0.0089% median sensitivity. qPCR targeting NPM1 mutation detected relapse 46 days before ddPCR (p = .03). ddPCR detected relapse 34.5 days before qPCR targeting WT1 overexpression (p = .03). In non-relapsing patients, zero false positive ddPCR MRD relapses were observed even when monitoring targets associated with clonal haematopoiesis such as DNMT3A, TET2, and ASXL1 mutations.
CONCLUSION: These results confirm that qPCR targeting NPM1 mutations or fusion transcripts are superior in MRD testing. In the absence of such targets, ddPCR is a promising alternative demonstrating (a) high applicability, (b) high sensitivity, and (c) zero false positive MRD relapses in non-relapsing patients.

Keywords:  AML; acute myeloid leukaemia; ddPCR; haematopoietic stem cell transplantation; measurable residual disease

DOI:  https://doi.org/10.1111/ejh.14151
Bone Marrow Transplant. 2024 Jan 09.

Allogeneic haematopoietic cell transplantation for therapy-related myeloid neoplasms arising following treatment for lymphoma: a retrospective study on behalf of the Chronic Malignancies Working Party of the EBMT.

Mitja Nabergoj, Diderik-Jan Eikema, Linda Koster, Uwe Platzbecker, Katja Sockel, Jürgen Finke, Nicolaus Kröger, Edouard Forcade, Arnon Nagler, Matthias Eder, Johanna Tischer, Annoek E C Broers, Jürgen Kuball, Keith M O Wilson, Mathilde Hunault-Berger, Matthew Collin, Domenico Russo, Lucía López Corral, Grzegorz Helbig, Alberto Mussetti, Christof Scheid, Carmelo Gurnari, Kavita Raj, Joanna Drozd-Sokolowska, Ibrahim Yakoub-Agha, Marie Robin, Donal P McLornan.

Therapy-related myeloid neoplasms (t-MN), either myelodysplastic neoplasms (t-MDS) or acute myeloid leukemias (t-AML), have a poor prognosis and allogeneic haematopoietic cell transplantation (allo-HCT) represents the only curative option. In this multicenter, registry-based study, we analyzed outcomes of 378 patients undergoing first allo-HCT between 2006-2017 for t-MN arising secondary to lymphoma treatment. Median age was 58 years at allo-HCT; 222 (59%) had a diagnosis of t-MDS and 156 (41%) of t-AML, respectively. At the time of allo-HCT, 46% of t-MN cases were reported as in complete remission (CR) and 15% of lymphomas were recorded as not in remission. A reduced intensity conditioning regimen was used in 70% of cases. For the entire cohort, 5-year OS, and t-MN PFS, relapse incidence and NRM were 32%, 28%, 35% and 37%, respectively. In multivariable analysis, undergoing allo-HCT with t-MN not in CR and older age were associated with significantly worse OS, PFS and NRM. At 5 years post allo-HCT, the relapse incidence of lymphoma was low at 3%, while the rate of secondary malignancies was 8%. This analysis shows the curative potential of allo-HCT for patients with t-MN arising secondary to lymphoma treatment in approximately a third of patients.

DOI: https://doi.org/10.1038/s41409-023-02193-z
Blood Adv. 2024 Jan 10. pii: bloodadvances.2023010435. [Epub ahead of print]

Monosomy 7/del(7q) Cause Sensitivity to Inhibitors of Nicotinamide Phosphoribosyltransferase in Acute Myeloid Leukemia.

Samuli Eldfors, Joseph Saad, Nemo Koi Ikonen, Disha Malani, Markus Vähä-Koskela, Bjorn T Gjertsen, Mika Kontro, Kimmo Porkka, Caroline A Heckman.

Monosomy 7 and del(7q) (-7/-7q) are frequent chromosomal abnormalities detected in up to 10% of patients with acute myeloid leukemia (AML). Despite unfavorable treatment outcomes, no approved targeted therapies exist for patients with -7/-7q. Therefore, we aimed to identify novel vulnerabilities. Through an analysis of data from ex vivo drug screens of 114 primary AML samples, we discovered that -7/-7q AML cells are highly sensitive to the inhibition of nicotinamide phosphoribosyltransferase (NAMPT). NAMPT is the rate-limiting enzyme in the NAD+ salvage pathway. Mechanistically, the NAMPT gene is located at 7q22.3, and deletion of one copy due to -7/-7q results in NAMPT haploinsufficiency, leading to reduced expression and a therapeutically targetable vulnerability to the inhibition of NAMPT. Our results show that in -7/-7q AML, differentiated CD34+CD38+ myeloblasts are more sensitive to the inhibition of NAMPT than less differentiated CD34+CD38- myeloblasts. Furthermore, the combination of the BCL2 inhibitor venetoclax and the NAMPT inhibitor KPT-9274 resulted in the death of significantly more leukemic blasts in AML samples with -7/-7q compared to the NAMPT inhibitor alone. In conclusion, our findings demonstrate that AML with -7/-7q are highly sensitive to NAMPT inhibition, suggesting that NAMPT inhibitors have the potential to be an effective targeted therapy for patients with monosomy 7 or del(7q).

DOI: https://doi.org/10.1182/bloodadvances.2023010435
Blood Adv. 2024 Jan 09. 8(1): 80-92

Linking GATA2 to myeloid dysplasia and complex cytogenetics in adult myelodysplastic neoplasm and acute myeloid leukemia.

Daniel J Robbins, Tatiana S Pavletich, Apoorva T Patil, Demetra Pahopos, Michael Lasarev, Usha S Polaki, Zhubin J Gahvari, Emery H Bresnick, Daniel R Matson.

ABSTRACT: GATA binding protein 2 (GATA2) is a conserved zinc finger transcription factor that regulates the emergence and maintenance of complex genetic programs driving development and function of hematopoietic stem and progenitor cells (HSPCs). Patients born with monoallelic GATA2 mutations develop myelodysplastic neoplasm (MDS) and acute myeloid leukemia (AML), whereas acquired GATA2 mutations are reported in 3% to 5% of sporadic AML cases. The mechanisms by which aberrant GATA2 activity promotes MDS and AML are incompletely understood. Efforts to understand GATA2 in basic biology and disease will be facilitated by the development of broadly efficacious antibodies recognizing physiologic levels of GATA2 in diverse tissue types and assays. Here, we purified a polyclonal anti-GATA2 antibody and generated multiple highly specific anti-GATA2 monoclonal antibodies, optimized them for immunohistochemistry on patient bone marrow bioosy samples, and analyzed GATA2 expression in adults with healthy bone marrow, MDS, and acute leukemia. In healthy bone marrow, GATA2 was detected in mast cells, subsets of CD34+ HSPCs, E-cadherin-positive erythroid progenitors, and megakaryocytes. In MDS, GATA2 expression correlates with bone marrow blast percentage, positively correlates with myeloid dysplasia and complex cytogenetics, and is a nonindependent negative predictor of overall survival. In acute leukemia, the percent of GATA2+ blasts closely associates with myeloid lineage, whereas a subset of lymphoblastic and undifferentiated leukemias with myeloid features also express GATA2. However, the percent of GATA2+ blasts in AML is highly variable. Elevated GATA2 expression in AML blasts correlates with peripheral neutropenia and complex AML cytogenetics but, unlike in MDS, does not predict survival.

DOI: https://doi.org/10.1182/bloodadvances.2023011554
Blood. 2024 Jan 11. pii: blood.2023021342. [Epub ahead of print]

KBTBD4-mediated Reduction of MYC Is Critical For Hematopoietic Stem Cell Expansion Upon UM171 Treatment.

Jalila Chagraoui, Simon Girard, Laure Mallinger, Nadine Mayotte, Maria Florencia Tellechea, Guy Sauvageau.

Ex vivo expansion of hematopoietic stem cells (HSCs) is gaining in importance for cell and gene therapy and requires a shift from dormancy state to activation and cycling. However, abnormal or excessive HSC activation results in reduced self-renewal ability and increased propensity for myeloid-biased differentiation. We now report that activation of the E3 ligase complex CRL3KBTBD4 by UM171 not only induces epigenetic changes through CoREST1 degradation but also controls chromatin bound MYC levels to prevent excessive activation and maintain lympho-myeloid potential of expanded populations. Furthermore, reconstitution activity and multipotency of UM171-treated HSC is specifically compromised when MYC levels are experimentally increased despite degradation of CoREST1.

DOI: https://doi.org/10.1182/blood.2023021342
Blood Adv. 2024 Jan 11. pii: bloodadvances.2023011338. [Epub ahead of print]

IL-1β promotes MPN disease initiation by favoring early clonal expansion of JAK2-mutant hematopoietic stem cells.

Shivam Rai, Yang Zhang, Elodie Grockowiak, Quentin Kimmerlin, Nils Hansen, Cedric B Stoll, Marc Usart, Damien Luque Paz, Hui Hao-Shen, Yexuan Zhu, Julien Roux, Michael S Bader, Stefan Dirnhofer, Christopher J Farady, Timm Schroeder, Simón Méndez-Ferrer, Radek C Skoda.

JAK2-V617F is the most frequent somatic mutation causing myeloproliferative neoplasm (MPN). JAK2-V617F can be found in healthy individuals with clonal hematopoiesis of indeterminate potential (CHIP) with a frequency much higher than the prevalence of MPN. The factors controlling the conversion of JAK2-V617F CHIP to MPN are largely unknown. We hypothesized that IL-1β mediated inflammation can favor this progression. We established an experimental system using bone marrow (BM) transplantations from JAK2-V617F and GFP transgenic (VF;GFP) mice, that were further crossed with IL-1β-/- or IL-1R1-/- mice. To study the role of IL-1β and its receptor on monoclonal evolution of MPN, we performed competitive BM transplantations at high dilutions with only 1-3 hematopoietic stem cells (HSCs) per recipient. Loss of IL-1β in JAK2-mutant HSCs reduced engraftment, restricted clonal expansion, lowered the total numbers of functional HSCs, and decreased the rate of conversion to MPN. Loss of IL-1R1 in the recipients also lowered the conversion to MPN, but did not reduce the frequency of engraftment of JAK2-mutant HSCs. WT recipients transplanted with VF;GFP BM that developed MPN had elevated IL-1β levels and reduced frequencies of mesenchymal stromal cells (MSCs). Interestingly, frequencies of MSCs were also reduced in recipients that did not develop MPN, had only marginally elevated IL-1β levels and displayed low GFP-chimerism resembling CHIP. Anti-IL-1β antibody preserved high frequencies of MSCs in VF;GFP recipients and reduced the rate of engraftment and the conversion to MPN. Our results identify IL-1β as a potential therapeutic target for preventing the transition from JAK2-V617F CHIP to MPN.

DOI: https://doi.org/10.1182/bloodadvances.2023011338
Blood. 2024 Jan 09. pii: blood.2023021815. [Epub ahead of print]

The remission status of AML patients post alloSCT is associated with a distinct single-cell bone marrow T cell signature.

Anna Mathioudaki, Xizhe Wang, David Nikolov Sedloev, Richard Huth, Aryan Kamal, Michael Hundemer, Yi Liu, Spyridoula Vasileiou, Premal D Lulla, Carsten Müller-Tidow, Peter Dreger, Thomas Luft, Tim Sauer, Michael Schmitt, Judith B Zaugg, Caroline Pabst.

Acute myeloid leukemia (AML) is a hematologic malignancy for which allogeneic stem cell transplantation (alloSCT) often remains the only curative therapeutic approach. However, incapability of T cells to recognize and eliminate residual leukemia stem cells (LSCs) might lead to an insufficient graft-versus-leukemia (GvL) effect and relapse. Here, we performed single-cell RNA-sequencing on bone marrow (BM) T lymphocytes and CD34+ cells of six AML patients 100 days after alloSCT to identify T cell signatures associated with either imminent relapse (REL) or durable complete remission (CR). We observed a higher frequency of cytotoxic CD8+ effector and gamma delta (γδ) T cells in CR versus REL samples. Pseudotime and gene regulatory network analyses revealed that CR CD8+ T cells were more advanced in maturation and had a stronger cytotoxicity signature, while REL samples were characterized by inflammatory TNF/NF-κB signaling and an immunosuppressive milieu. We identified ADGRG1/GPR56 as a surface marker enriched in CR CD8+ T cells and confirmed in a CD33-directed chimeric antigen receptor (CAR)-T/AML co-culture model that GPR56 becomes upregulated on T cells upon antigen encounter and elimination of AML cells. We show that GPR56 continuously increases at the protein level on CD8+ T cells after alloSCT and confirm faster IFNγ secretion upon re-exposure to matched, but not unmatched recipient AML cells in the GPR56+ versus GPR56- CD8+ T cell fraction. Together, our data provide a single-cell reference map of BM-derived T cells post alloSCT and propose GPR56 expression dynamics as a surrogate for antigen encounter post alloSCT.

DOI: https://doi.org/10.1182/blood.2023021815
Blood Adv. 2024 Jan 10. pii: bloodadvances.2023012120. [Epub ahead of print]

Prophylactic maintenance with venetoclax/azacitidine after reduced intensity conditioning allo-transplant for high risk MDS and AML.

Jacqueline S Garcia, Haesook T Kim, H Moses Murdock, Michela Ansuinelli, Jennifer Brock, Corey S Cutler, Mahasweta Gooptu, Vincent T Ho, John Koreth, Sarah Nikiforow, Rizwan Romee, Roman M Shapiro, Daniel J DeAngelo, Richard M Stone, Denbaa Bat-Erdene, Jeremy Adam Ryan, Manuel E Contreras, Geoffrey Fell, Anthony Letai, Jerome Ritz, R Coleman Lindsley, Robert J Soiffer, Joseph H Antin.

We conducted a phase 1 trial assessing safety and efficacy of prophylactic maintenance therapy with venetoclax and azacitidine (Ven/Aza) in patients with high risk myelodysplastic syndromes (MDS)/acute myeloid leukemia (AML) undergoing reduced intensity allogeneic hematopoietic stem cell transplantation following venetoclax and FluBu2-conditioning (Ven/FluBu2 allo-SCT) with tacrolimus and methotrexate as graft-versus-host disease (GVHD) prophylaxis. Among 27 patients who underwent Ven/FluBu2 allo-SCT (55.6% prior venetoclax exposure and 96% molecular measurable residual disease (MRD)-positive), 22 received maintenance therapy with azacitidine 36 mg/m2 intravenously on days 1-5 and venetoclax 400 mg by mouth on days 1-14 on one of two schedules (42-day cycles x 8 or 28-day cycles x 12). During maintenance, the most common grade 3/4 adverse events were leukopenia, neutropenia and thrombocytopenia, which were transient and manageable. Infections were uncommon (n=4, all grade 1-2). The 1-year and 2-year moderate/severe chronic GVHD rates were 4% (95% CI, 0.3-18%) and 22% (95% CI, 9-40%). After a median follow-up of 25-months among survivors, median overall survival (OS) was not reached. In the 22 patients who received Ven/Aza maintenance, the 2-year OS, progression-free survival, non-relapse mortality, and cumulative incidence of relapse rates were 67% (95% CI, 43-83%), 59% (95% CI, 36-76%), 0%, and 41% (95% CI, 20-61%), respectively. Immune monitoring demonstrated no significant impact on T cell expansion, but identified reduced B cell expansion compared to controls. This study demonstrates prophylactic Ven/Aza maintenance can be safely administered in high risk MDS/AML patients, but a randomized study is required to properly assess any potential benefit. (NCT03613532).

DOI: https://doi.org/10.1182/bloodadvances.2023012120
Blood. 2024 Jan 11. pii: blood.2023022082. [Epub ahead of print]

Hematopoietic stem cell quiescence and DNA replication dynamics maintained by the resilient β-catenin/Hoxa9/Prmt1 axis.

Jennifer Lynch, Estelle Troadec, Tsz Kan Fung, Kornelia Gladysz, Clemence Virely, Priscilla Nga Ieng Lau, Ngai Cheung, Bernd Zeisig, Jason Wing Hon Wong, Massimo Lopes, Suming Huang, Chi Wai Eric So.

Maintenance of quiescence and DNA replication dynamics are two paradoxical requirements for the distinct states of dormant and active hematopoietic stem cells (HSCs), which are required to preserve the stem cell reservoir and replenish the blood cell system in response to hematopoietic stress respectively. Here, we show that key self-renewal factors, β-catenin or Hoxa9, largely dispensable for HSC integrity in fact have dual functions in maintaining quiescence and enabling efficient DNA replication fork dynamics to preserve the functionality of hematopoietic stem and progenitor cells (HSPCs). While β-catenin or Hoxa9 single knockout (KO) exhibited mostly normal hematopoiesis, their co-inactivation led to severe hematopoietic defects stemmed from aberrant cell cycle, DNA replication and damage in HSPCs. Mechanistically, β-catenin and Hoxa9 function in a compensatory manner to sustain key transcriptional programs that converge on the pivotal downstream target and epigenetic modifying enzyme, Prmt1, which protects the quiescent state and ensures an adequate supply of DNA replication and repair factors to maintain robust replication fork dynamics. Inactivation of Prmt1 phenocopied both cellular and molecular phenotypes of β-catenin/Hoxa9 combined KO, which at the same time could also be partially rescued by Prmt1 expression. The discovery of the highly resilient β-catenin/Hoxa9/Prmt1 axis in protecting both quiescence and DNA replication dynamics essential for HSCs at different key states provides not only novel mechanistic insights into their intricate regulation but also a potential tractable target for therapeutic intervention.

DOI: https://doi.org/10.1182/blood.2023022082
Blood Adv. 2024 Jan 09. 8(1): 56-69

The nonessential amino acid cysteine is required to prevent ferroptosis in acute myeloid leukemia.

Alan Cunningham, Lieve L Oudejans, Marjan Geugien, Diego Antonio Pereira-Martins, Albertus T J Wierenga, Ayşegül Erdem, Dominique Sternadt, Gerwin Huls, Jan Jacob Schuringa.

ABSTRACT: Cysteine is a nonessential amino acid required for protein synthesis, the generation of the antioxidant glutathione, and for synthesizing the nonproteinogenic amino acid taurine. Here, we highlight the broad sensitivity of leukemic stem and progenitor cells to cysteine depletion. By CRISPR/CRISPR-associated protein 9-mediated knockout of cystathionine-γ-lyase, the cystathionine-to-cysteine converting enzyme, and by metabolite supplementation studies upstream of cysteine, we functionally prove that cysteine is not synthesized from methionine in acute myeloid leukemia (AML) cells. Therefore, although perhaps nutritionally nonessential, cysteine must be imported for survival of these specific cell types. Depletion of cyst(e)ine increased reactive oxygen species (ROS) levels, and cell death was induced predominantly as a consequence of glutathione deprivation. nicotinamide adenine dinucleotide phosphate hydrogen oxidase inhibition strongly rescued viability after cysteine depletion, highlighting this as an important source of ROS in AML. ROS-induced cell death was mediated via ferroptosis, and inhibition of glutathione peroxidase 4 (GPX4), which functions in reducing lipid peroxides, was also highly toxic. We therefore propose that GPX4 is likely key in mediating the antioxidant activity of glutathione. In line, inhibition of the ROS scavenger thioredoxin reductase with auranofin also impaired cell viability, whereby we find that oxidative phosphorylation-driven AML subtypes, in particular, are highly dependent on thioredoxin-mediated protection against ferroptosis. Although inhibition of the cystine-glutamine antiporter by sulfasalazine was ineffective as a monotherapy, its combination with L-buthionine-sulfoximine (BSO) further improved AML ferroptosis induction. We propose the combination of either sulfasalazine or antioxidant machinery inhibitors along with ROS inducers such as BSO or chemotherapy for further preclinical testing.

DOI: https://doi.org/10.1182/bloodadvances.2023010786
J Clin Oncol. 2024 Jan 12. JCO2300943

Fludarabine, Cytarabine, Granulocyte Colony-Stimulating Factor, and Idarubicin With Gemtuzumab Ozogamicin Improves Event-Free Survival in Younger Patients With Newly Diagnosed AML and Overall Survival in Patients With NPM1 and FLT3 Mutations.

PORTEC Study Group

PURPOSE: To determine the optimal induction chemotherapy regimen for younger adults with newly diagnosed AML without known adverse risk cytogenetics.
PATIENTS AND METHODS: One thousand thirty-three patients were randomly assigned to intensified (fludarabine, cytarabine, granulocyte colony-stimulating factor, and idarubicin [FLAG-Ida]) or standard (daunorubicin and Ara-C [DA]) induction chemotherapy, with one or two doses of gemtuzumab ozogamicin (GO). The primary end point was overall survival (OS).
RESULTS: There was no difference in remission rate after two courses between FLAG-Ida + GO and DA + GO (complete remission [CR] + CR with incomplete hematologic recovery 93% v 91%) or in day 60 mortality (4.3% v 4.6%). There was no difference in OS (66% v 63%; P = .41); however, the risk of relapse was lower with FLAG-Ida + GO (24% v 41%; P < .001) and 3-year event-free survival was higher (57% v 45%; P < .001). In patients with an NPM1 mutation (30%), 3-year OS was significantly higher with FLAG-Ida + GO (82% v 64%; P = .005). NPM1 measurable residual disease (MRD) clearance was also greater, with 88% versus 77% becoming MRD-negative in peripheral blood after cycle 2 (P = .02). Three-year OS was also higher in patients with a FLT3 mutation (64% v 54%; P = .047). Fewer transplants were performed in patients receiving FLAG-Ida + GO (238 v 278; P = .02). There was no difference in outcome according to the number of GO doses, although NPM1 MRD clearance was higher with two doses in the DA arm. Patients with core binding factor AML treated with DA and one dose of GO had a 3-year OS of 96% with no survival benefit from FLAG-Ida + GO.
CONCLUSION: Overall, FLAG-Ida + GO significantly reduced relapse without improving OS. However, exploratory analyses show that patients with NPM1 and FLT3 mutations had substantial improvements in OS. By contrast, in patients with core binding factor AML, outcomes were excellent with DA + GO with no FLAG-Ida benefit.

DOI: https://doi.org/10.1200/JCO.23.00943
Genome Biol. 2024 Jan 12. 25(1): 16

RNA-binding protein RBM5 plays an essential role in acute myeloid leukemia by activating the oncogenic protein HOXA9.

Mengli Zhang, Judith Hyle, Xiaowen Chen, Ye Xin, Yingcai Jin, Jianxiang Zhang, Xue Yang, Xinfeng Chen, Shaela Wright, Zhenling Liu, Wojciech Rosikiewicz, Beisi Xu, Liusheng He, Hong Liu, Nana Ping, Depei Wu, Feiqiu Wen, Chunliang Li, Peng Xu.

   BACKGROUND: The oncogenic protein HOXA9 plays a critical role in leukemia transformation and maintenance, and its aberrant expression is a hallmark of most aggressive acute leukemia. Although inhibiting the upstream regulators of HOXA9 has been proven as a significant therapeutic intervention, the comprehensive regulation network controlling HOXA9 expression in leukemia has not been systematically investigated.
RESULTS: Here, we perform genome-wide CRISPR/Cas9 screening in the HOXA9-driven reporter acute leukemia cells. We identify a poorly characterized RNA-binding protein, RBM5, as the top candidate gene required to maintain leukemia cell fitness. RBM5 is highly overexpressed in acute myeloid leukemia (AML) patients compared to healthy individuals. RBM5 loss triggered by CRISPR knockout and shRNA knockdown significantly impairs leukemia maintenance in vitro and in vivo. Through domain CRISPR screening, we reveal that RBM5 functions through a noncanonical transcriptional regulation circuitry rather than RNA splicing, such an effect depending on DNA-binding domains. By integrative analysis and functional assays, we identify HOXA9 as the downstream target of RBM5. Ectopic expression of HOXA9 rescues impaired leukemia cell proliferation upon RBM5 loss. Importantly, acute protein degradation of RBM5 through auxin-inducible degron system immediately reduces HOXA9 transcription.
CONCLUSIONS: We identify RBM5 as a new upstream regulator of HOXA9 and reveal its essential role in controlling the survival of AML. These functional and molecular mechanisms further support RBM5 as a promising therapeutic target for myeloid leukemia treatment.

Keywords:  Acute myeloid leukemia; CRISPR screen; Genome editing; HOXA9; RBM5

DOI:  https://doi.org/10.1186/s13059-023-03149-8
Cell Death Dis. 2024 Jan 10. 15(1): 25

Evaluation of apoptosis stimulating protein of TP53-1 (ASPP1/PPP1R13B) to predict therapy resistance and overall survival in acute myeloid leukemia (AML).

Marcus M Schittenhelm, Max Kaiser, Balázs Győrffy, Kerstin M Kampa-Schittenhelm.

ASPP1 (PPP1R13B) belongs to a family of p53-binding proteins and enhances apoptosis by stimulation of p53-transactivation of selected proapoptotic target genes. It is preferentially expressed in hematopoietic stem cells (HSC) and together with p53 preserves the genomic integrity of the HSC pool. Consequently, dysfunction of ASPP1 has been associated with malignant transformation and development of acute lymphoblastic leukemias and lymphomas - whereas methylation of the promoter region is linked to reduced transcription and ultimately attenuated expression of ASPP1. The role of ASPP1 in AML is not known. We now show that impaired regulation of PPP1R13B contributes to the biology of leukemogenesis and primary therapy resistance in AML. PPP1R13B mRNA expression patterns thereby define a distinct prognostic profile - which is not reflected by the European leukemia net (ELN) risk score. These findings have direct therapeutic implications and we provide a strategy to restore ASPP1 protein levels using hypomethylating agents to sensitize cells towards proapoptotic drugs. Prospective clinical trials are warranted to investigate the role of ASPP1 (PPP1R13B) as a biomarker for risk stratification and as a potential therapeutic target to restore susceptibility to chemotherapy.

DOI: https://doi.org/10.1038/s41419-023-06372-0
Cell Stem Cell. 2023 Dec 29. pii: S1934-5909(23)00431-9. [Epub ahead of print]

A time- and single-cell-resolved model of murine bone marrow hematopoiesis.

Iwo Kucinski, Joana Campos, Melania Barile, Francesco Severi, Natacha Bohin, Pedro N Moreira, Lewis Allen, Hannah Lawson, Myriam L R Haltalli, Sarah J Kinston, Dónal O'Carroll, Kamil R Kranc, Berthold Göttgens.

  The paradigmatic hematopoietic tree model is increasingly recognized to be limited, as it is based on heterogeneous populations largely defined by non-homeostatic assays testing cell fate potentials. Here, we combine persistent labeling with time-series single-cell RNA sequencing to build a real-time, quantitative model of in vivo tissue dynamics for murine bone marrow hematopoiesis. We couple cascading single-cell expression patterns with dynamic changes in differentiation and growth speeds. The resulting explicit linkage between molecular states and cellular behavior reveals widely varying self-renewal and differentiation properties across distinct lineages. Transplanted stem cells show strong acceleration of differentiation at specific stages of erythroid and neutrophil production, illustrating how the model can quantify the impact of perturbations. Our reconstruction of dynamic behavior from snapshot measurements is akin to how a kinetoscope allows sequential images to merge into a movie. We posit that this approach is generally applicable to understanding tissue-scale dynamics at high resolution.

Keywords:  Hoxb5; differentiation rate; dynamics; hematopoiesis; modeling; progenitors; scRNA-seq; self-renewal; stem cells

DOI:  https://doi.org/10.1016/j.stem.2023.12.001
Blood Adv. 2024 Jan 09. 8(1): 70-79

Deep learning predicts therapy-relevant genetics in acute myeloid leukemia from Pappenheim-stained bone marrow smears.

Jacqueline Kockwelp, Sebastian Thiele, Jannis Bartsch, Lars Haalck, Jörg Gromoll, Stefan Schlatt, Rita Exeler, Annalen Bleckmann, Georg Lenz, Sebastian Wolf, Björn Steffen, Wolfgang E Berdel, Christoph Schliemann, Benjamin Risse, Linus Angenendt.

ABSTRACT: The detection of genetic aberrations is crucial for early therapy decisions in acute myeloid leukemia (AML) and recommended for all patients. Because genetic testing is expensive and time consuming, a need remains for cost-effective, fast, and broadly accessible tests to predict these aberrations in this aggressive malignancy. Here, we developed a novel fully automated end-to-end deep learning pipeline to predict genetic aberrations directly from single-cell images from scans of conventionally stained bone marrow smears already on the day of diagnosis. We used this pipeline to compile a multiterabyte data set of >2 000 000 single-cell images from diagnostic samples of 408 patients with AML. These images were then used to train convolutional neural networks for the prediction of various therapy-relevant genetic alterations. Moreover, we created a temporal test cohort data set of >444 000 single-cell images from further 71 patients with AML. We show that the models from our pipeline can significantly predict these subgroups with high areas under the curve of the receiver operating characteristic. Potential genotype-phenotype links were visualized with 2 different strategies. Our pipeline holds the potential to be used as a fast and inexpensive automated tool to screen patients with AML for therapy-relevant genetic aberrations directly from routine, conventionally stained bone marrow smears already on the day of diagnosis. It also creates a foundation to develop similar approaches for other bone marrow disorders in the future.

DOI: https://doi.org/10.1182/bloodadvances.2023011076
Comput Biol Med. 2023 Dec 21. pii: S0010-4825(23)01354-9. [Epub ahead of print]169 107889

Synergy and antagonism between azacitidine and FLT3 inhibitors.

Jingmei Yang, Ran Friedman.

  Synergetic interactions between drugs can make a drug combination more effective. Alternatively, they may allow to use lower concentrations and thus avoid toxicities or side effects that not only cause discomfort but might also reduce the overall survival. Here, we studied whether synergy exists between agents that are used for treatment of acute myeloid leukaemia (AML). Azacitidine is a demethylation agent that is used in the treatment of AML patients that are unfit for aggressive chemotherapy. An activating mutation in the FLT3 gene is common in AML patients and in the absence of specific treatment makes prognosis worse. FLT3 inhibitors may be used in such cases. We sought to determine whether combination of azacitidine with a FLT3 inhibitor (gilteritinib, quizartinib, LT-850-166, FN-1501 or FF-10101) displayed synergy or antagonism. To this end, we calculated dose-response matrices of these drug combinations from experiments in human AML cells and subsequently analysed the data using a novel consensus scoring algorithm. The results show that combinations that involved non-covalent FLT3 inhibitors, including the two clinically approved drugs gilteritinib and quizartinib were antagonistic. On the other hand combinations with the covalent inhibitor FF-10101 had some range of concentrations where synergy was observed.

Keywords:  Cancer treatment; Combination therapy; FF-10101; Kinase inhibitors

DOI:  https://doi.org/10.1016/j.compbiomed.2023.107889
Blood. 2024 Jan 09. pii: blood.2023021349. [Epub ahead of print]

First-hit SETBP1 mutations cause a myeloproliferative disorder with bone marrow fibrosis.

Ilaria Crespiatico, Mattia Zaghi, Cristina Mastini, Deborah D'Aliberti, Mario Mauri, Carl Mirko Mercado, Diletta Fontana, Silvia Spinelli, Valentina Crippa, Elena Inzoli, Beatrice Manghisi, Ivan Civettini, Daniele Ramazzotti, Valentina Sangiorgio, Michele Gengotti, Virginia Brambilla, Andrea Aroldi, Federica Banfi, Cristiana Barone, Roberto Orsenigo, Ludovica Riera, Mara Riminucci, Alessandro Corsi, Massimo Breccia, Alessandro Morotti, Daniela Cilloni, Aldo M Roccaro, Antonio Sacco, Fabio Stagno, Marta Serafini, Federica Mottadelli, Giovanni Cazzaniga, Fabio Pagni, Roberto Chiarle, Emanuele Azzoni, Alessandro Sessa, Carlo B Gambacorti-Passerini, Elena Maria Elli, Luca Mologni, Rocco Piazza.

SETBP1 mutations are found in various clonal myeloid disorders. However, it is unclear whether they can initiate leukemia, as SETBP1 mutations typically appear as later events during oncogenesis. To answer this question, we generated a mouse model expressing mutated SETBP1 in hematopoietic tissue: this model showed profound alterations in the differentiation program of hematopoietic progenitors and developed a myeloid neoplasm with megakaryocytic dysplasia, splenomegaly, and bone marrow fibrosis, prompting us to investigate SETBP1 mutations in a cohort of 36 triple-negative primary myelofibrosis (TN-PMF) cases. We identified two distinct subgroups, one carrying SETBP1 mutations and the other completely devoid of somatic variants. Clinically, a striking difference in disease aggressiveness was noted, with SETBP1-mutated patients showing a much worse clinical course. As opposite to myelodysplastic/myeloproliferative neoplasms, where SETBP1 mutations are mostly found as a late clonal event, single-cell clonal hierarchy reconstruction in three TN-PMF patients from our cohort revealed SETBP1 to be a very early event, suggesting that the phenotype of the different SETBP1+ disorders may be shaped by the opposite hierarchy of the same clonal SETBP1 variants.

DOI: https://doi.org/10.1182/blood.2023021349
Blood Adv. 2024 Jan 10. pii: bloodadvances.2023011324. [Epub ahead of print]

Risk Factors for Clonal Hematopoiesis of Indeterminate Potential in People with HIV: a report from the REPRIEVE Trial.

Romit Bhattacharya, Md Mesbah Uddin, Aniruddh P Patel, Abhishek Niroula, Phoebe Finneran, Rachel Bernardo, Kathleen V Fitch, Michael T Lu, Gerald S Bloomfield, Carlos Malvestutto, Judith A Aberg, Carl J Fichtenbaum, Whitney Hornsby, Heather Ribaudo, Peter Libby, Benjamin L Ebert, Markella Zanni, Pamela Douglas, Steven Grinspoon, Pradeep Natarajan.

Clonal hematopoiesis of Indeterminate Potential (CHIP), the clonal expansion of myeloid cells with leukemogenic mutations, results in increased coronary artery disease (CAD) risk. CHIP is more prevalent among people with HIV (PWH) but the risk factors are unknown. CHIP was identified among PWH in REPRIEVE (Randomized Trial to Prevent Vascular Events in HIV) using whole exome sequencing (WES). Logistic regression was used to associate sociodemographic factors and HIV-specific factors with CHIP adjusting for age, sex, and smoking status. In the studied global cohort of 4,486 PWH, mean (SD) age was 49.9 (6.4) years, 1650 (36.8%) were female, and 3418 (76.2%) were non-White. CHIP was identified in 223/4486 (4.97%), and in 38/373 (10.2%) among those 60 years of age or older. Age (OR 1.07, 95%CI 1.05-1.09, p<0.0001) and smoking (OR 1.37, 95%CI 1.14-1.66, p<0.001) associated with increased odds of CHIP. Globally, participants outside of North America had lower odds of CHIP including Sub-Saharan Africa (OR 0.57, 95%CI 0.4-0.81, p=0.0019), South Asia (OR 0.45, 95%CI 0.23-0.80, p=0.01), and Latin America/Caribbean (OR 0.56, 95%CI 0.34-0.87, p=0.014). Hispanic/Latino ethnicity (OR 0.38, 95%CI 0.23-0.54, p=0.002) associated with significantly lower odds of CHIP. Among HIV-specific factors, CD4 nadir <50 cells/mm3 associated with a 1.9-fold (95%CI 1.21-3.05, p=0.006) increased odds of CHIP, with the effect being significantly stronger among individuals with short duration of antiretroviral therapy (ART) (OR 4.15, 95%CI 1.51-11.1, p=0.005) (pinteraction=0.0492). Among PWH at low-to-moderate CAD risk on stable ART, smoking, CD4 nadir, North American origin, and non-Hispanic ethnicity associated with increased odds of CHIP. Clinical Trials Registration: NCT02344290.

DOI: https://doi.org/10.1182/bloodadvances.2023011324
Cold Spring Harb Perspect Med. 2024 Jan 08. pii: a041537. [Epub ahead of print]

Isocitrate Dehydrogenase Mutations in Cancer: Mechanisms of Transformation and Metabolic Liability.

Kathryn Gunn, Julie-Aurore Losman.

Isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) are metabolic enzymes that interconvert isocitrate and 2-oxoglutarate (2OG). Gain-of-function mutations in IDH1 and IDH2 occur in a number of cancers, including acute myeloid leukemia, glioma, cholangiocarcinoma, and chondrosarcoma. These mutations cripple the wild-type activity of IDH and cause the enzymes to catalyze a partial reverse reaction in which 2OG is reduced but not carboxylated, resulting in production of the (R)-enantiomer of 2-hydroxyglutarate ((R)-2HG). (R)-2HG accumulation in IDH-mutant tumors results in profound dysregulation of cellular metabolism. The most well-characterized oncogenic effects of (R)-2HG involve the dysregulation of 2OG-dependent epigenetic tumor-suppressor enzymes. However, (R)-2HG has many other effects in IDH-mutant cells, some that promote transformation and others that induce metabolic dependencies. Herein, we review how cancer-associated IDH mutations impact epigenetic regulation and cellular metabolism and discuss how these effects can potentially be leveraged to therapeutically target IDH-mutant tumors.

DOI: https://doi.org/10.1101/cshperspect.a041537
Haematologica. 2024 Jan 04.

Matched unrelated donor transplantation versus haploidentical transplantation with post-transplant cyclophosphamide in children with acute myeloid leukemia: a PDWP-EBMT study.

Annalisa Ruggeri, Nicole Santoro, Jacques-Emmanuel Galimard, Krzysztof Kalwak, Mattia Algeri, Ludmila Zubarovskaya, Krzysztof Czyzewski, Elena Skorobogatova, Petr Sedlacek, Caroline Besley, Adriana Balduzzi, Yves Bertrand, Julia Peristeri, Franca Fagioli, Mariane Ifversen, Jolanta Gozdzik, Christina Peters, Birgitta Versluijs, Alessandra Biffi, Arcangelo Prete, Maura Faraci, Ibrahim Ghemlas, Ivana Bodova, Olga Aleinikova, Arnaud Dalissier, Vanderson Rocha, Selim Corbacioglu.

In children with acute myeloid leukemia (AML) who lack an HLA identical sibling, the donor can be replaced with an HLA matched unrelated donor (MUD) or a haploidentical donor (haplo). We compared outcomes of patients <18 years with AML in first and second complete remission (CR1 and CR2) undergoing a hematopoietic stem cell transplantation (HCT) either with a MUD with anti-thymocyte globuline (ATG) (n=420) or a haplo HCT with PT-CY (n=96) after a myeloablative conditioning regimen (MAC) between 2011 and 2021, reported to EBMT. A matched pair analysis was performed to adjust for differences among groups. The final analysis was performed on 253 MUD and 95 haplo-HCTs. In the matched cohort, median age at HCT was 11.2 and 10 years and median year of HCT was 2017 and 2018, in MUD and haplo- HCT recipients, respectively. The risk of grade III-IV aGvHD was significantly higher in the haplo group (HR=2.33, 95%CI1.18-4.58, p=0.03). No significant differences were found in 2 years overall survival (OS; 78.4%vs71.5%; HR 1.39, 0.84-2.31, p=0.19), leukemia-free-survival (LFS; 72.7%vs69.5%; HR1.22, 0.76-1.95, p=0.41), CI of relapse (RI; 19.3%vs19.5%; HR=1.14, 0.62-2.08, p=0.68) non-relapse-mortality (NRM; 8%vs11%; HR=1.39, 0.66-2.93, p=0.39) and graft versus host free-relapse free survival (GRFS; 60.7%vs54.5%, HR=1.38, 0.95-2.02, p=0.09) after MUD and haplo-HCT respectively. Our study suggests that haplo-HCT with PT-CY is a suitable option to transplant children with AML lacking a matched related donor.

DOI: https://doi.org/10.3324/haematol.2023.284445
J Clin Oncol. 2024 Jan 08. JCO2301071

Prevalence, Dynamics, and Prognostic Role of Clonal Hematopoiesis of Indeterminate Potential in Patients With Breast Cancer.

Stefania Morganti, Christopher J Gibson, Qingchun Jin, Katheryn Santos, Ashka Patel, Alex Wilson, Margaret Merrill, Julie Vincuilla, Samantha Stokes, Marla Lipsyc-Sharf, Tonia Parker, Tari A King, Elizabeth A Mittendorf, Giuseppe Curigliano, Melissa E Hughes, Daniel G Stover, Sara M Tolaney, Lachelle D Weeks, Nabihah Tayob, Nancy U Lin, Judy E Garber, Peter G Miller, Heather A Parsons.

PURPOSE: Clonal hematopoiesis of indeterminate potential (CHIP) is frequent in patients with solid tumors. Prospective data about CHIP prevalence at breast cancer diagnosis and its dynamic evolution under treatment selective pressure are limited.
PATIENTS AND METHODS: We performed targeted error-corrected sequencing on 614 samples from 380 patients with breast cancer. We investigated the dynamics of CHIP on prospectively collected paired samples from patients with early breast cancer (eBC) receiving chemotherapy (CT) or endocrine therapy (ET). We assessed the correlation of CHIP with survival in patients with metastatic triple-negative breast cancer (mTNBC). We estimated the risk of progression to treatment-related myeloid neoplasms (t-MN) according to the clonal hematopoiesis risk score (CHRS). In exploratory analyses, we considered clonal hematopoiesis (CH) with variant allele fraction (VAF) ≥0.005.
RESULTS: CHIP was identified in 15% of patients before treatment. Few CHIP emerged after treatment, and the risk of developing new mutations was similar for patients receiving CT versus ET (odds ratio [OR], 1.16; P = .820). However, CT increased the risk of developing new CH with VAF ≥0.005 (OR, 3.45; P = .002). Five TP53-mutant CH with VAF ≥0.005 emerged among patients receiving CT. Most patients had low risk of t-MN according to the CHRS score. CHIP did not correlate with survival in mTNBC.
CONCLUSION: CHIP is frequent in patients with breast cancer. In this study, CT did not lead to emergence of new CHIP, and most patients had low risk of developing t-MN. This finding is reassuring, given long life expectancy of patients with eBC and the association of CHIP with morbidity and mortality. However, TP53-mutant CH with VAF ≥0.005 emerged with CT, which carries high risk of t-MN. Evolution of these small clones and their clinical significance warrant further investigation.

DOI: https://doi.org/10.1200/JCO.23.01071
Lancet Haematol. 2024 Jan 03. pii: S2352-3026(23)00342-3. [Epub ahead of print]

Prophylaxis and management of graft-versus-host disease after stem-cell transplantation for haematological malignancies: updated consensus recommendations of the European Society for Blood and Marrow Transplantation.

Olaf Penack, Monia Marchetti, Mahmoud Aljurf, Mutlu Arat, Francesca Bonifazi, Rafael F Duarte, Sebastian Giebel, Hildegard Greinix, Mette D Hazenberg, Nicolaus Kröger, Stephan Mielke, Mohamad Mohty, Arnon Nagler, Jakob Passweg, Francesca Patriarca, Tapani Ruutu, Hélène Schoemans, Carlos Solano, Radovan Vrhovac, Daniel Wolff, Robert Zeiser, Anna Sureda, Zinaida Peric.

Graft-versus-host disease (GVHD) is a major factor contributing to mortality and morbidity after allogeneic haematopoietic stem-cell transplantation (HSCT). In the last 3 years, there has been regulatory approval of new drugs and considerable change in clinical approaches to prophylaxis and management of GVHD. To standardise treatment approaches, the European Society for Blood and Marrow Transplantation (EBMT) has updated its clinical practice recommendations. We formed a panel of one methodologist and 22 experts in the field of GVHD management. The selection was made on the basis of their role in GVHD management in Europe and their contributions to the field, such as publications, presentations at conferences, and other research. We applied the GRADE process to ten PICO (patient, intervention, comparator, and outcome) questions: evidence was searched for by the panel and graded for each crucial outcome. In two consensus meetings, we discussed the evidence and voted on the wording and strengths of recommendations. Key updates to the recommendations include: (1) primary use of ruxolitinib in steroid-refractory acute GVHD and steroid-refractory chronic GVHD as the new standard of care, (2) use of rabbit anti-T-cell (thymocyte) globulin or post-transplantation cyclophosphamide as standard GVHD prophylaxis in peripheral blood stem-cell transplantations from unrelated donors, and (3) the addition of belumosudil to the available treatment options for steroid-refractory chronic GVHD. The EBMT proposes to use these recommendations as the basis for routine management of GVHD during allogenic HSCT. The current recommendations favour European practice and do not necessarily represent global preferences.

DOI: https://doi.org/10.1016/S2352-3026(23)00342-3
Clin Lymphoma Myeloma Leuk. 2023 Dec 20. pii: S2152-2650(23)02197-3. [Epub ahead of print]

Real-world Effectiveness of Azacitidine in Treatment-Naive Patients With Higher-risk Myelodysplastic Syndromes.

Nishanthan Rajakumaraswamy, Mitul Gandhi, Andrew H Wei, David A Sallman, Naval G Daver, Shuyuan Mo, Shahed Iqbal, Roshan Karalliyadda, Manli Chen, Yunfei Wang, Paresh Vyas.

   INTRODUCTION: Azacitidine (AZA) is an approved frontline therapy for higher-risk myelodysplastic syndromes (HR-MDS); however, poor survival denotes unmet needs to increase depth/duration of response (DOR).
METHODS: This retrospective study with patient chart review evaluated AZA effectiveness in 382 treatment-naive patients with HR-MDS from a US electronic health record (EHR)-derived database. Responses were assessed using International Working Group (IWG) 2006 criteria; real-world equivalents were derived from EHRs. Primary endpoint was IWG 2006-based complete remission rate (CRR). Secondary endpoints were EHR-based CRR, IWG 2006- and EHR-based objective response rates (ORRs), duration of CR, DOR, progression-free survival, time-to-next-treatment, and overall survival (OS).
RESULTS: Using IWG 2006 criteria, the CRR was 7.9% (n = 30); median duration of CR was 12.0 months (95% CI, 7.7-15.6). In poor cytogenetic risk (n = 101) and TP53 mutation (n = 46) subgroups, CRRs were 7.9% (n = 8) and 8.7% (n = 4), respectively. ORR was 62.8% (n = 240), including a hematologic improvement rate (HIR) of 46.9% (n = 179). Using EHR-based data, CRR was 3.7% (n = 14); median duration of CR was 13.5 months (95% CI, 4.5-21.5). ORR was 67.8% (n = 259), including an HIR of 29.3% (n = 112). Median follow-up was 12.9 months; median OS was 17.9 months (95% CI, 15.5-21.7).
CONCLUSIONS: Consistent with other studies, CRRs and median OS with AZA in treatment-naive patients with HR-MDS were low in this large, real-world cohort. Novel agents/combinations are urgently needed to improve these outcomes in HR-MDS.

Keywords:  HR-MDS; MDS; Real-world data

DOI:  https://doi.org/10.1016/j.clml.2023.12.008
Nat Commun. 2024 Jan 10. 15(1): 446

ROCK1/2 signaling contributes to corticosteroid-refractory acute graft-versus-host disease.

Kristina Maas-Bauer, Anna-Verena Stell, Kai-Li Yan, Enrique de Vega, Janaki Manoja Vinnakota, Susanne Unger, Nicolas Núñez, Johana Norona, Nana Talvard-Balland, Stefanie Koßmann, Carsten Schwan, Cornelius Miething, Uta S Martens, Khalid Shoumariyeh, Rosa P Nestor, Sandra Duquesne, Kathrin Hanke, Michal Rackiewicz, Zehan Hu, Nadia El Khawanky, Sanaz Taromi, Hana Andrlova, Hemin Faraidun, Stefanie Walter, Dietmar Pfeifer, Marie Follo, Johannes Waldschmidt, Wolfgang Melchinger, Michael Rassner, Claudia Wehr, Annette Schmitt-Graeff, Sebastian Halbach, James Liao, Georg Häcker, Tilman Brummer, Joern Dengjel, Geoffroy Andrieux, Robert Grosse, Sonia Tugues, Bruce R Blazar, Burkhard Becher, Melanie Boerries, Robert Zeiser.

Patients with corticosteroid-refractory acute graft-versus-host disease (aGVHD) have a low one-year survival rate. Identification and validation of novel targetable kinases in patients who experience corticosteroid-refractory-aGVHD may help improve outcomes. Kinase-specific proteomics of leukocytes from patients with corticosteroid-refractory-GVHD identified rho kinase type 1 (ROCK1) as the most significantly upregulated kinase. ROCK1/2 inhibition improved survival and histological GVHD severity in mice and was synergistic with JAK1/2 inhibition, without compromising graft-versus-leukemia-effects. ROCK1/2-inhibition in macrophages or dendritic cells prior to transfer reduced GVHD severity. Mechanistically, ROCK1/2 inhibition or ROCK1 knockdown interfered with CD80, CD86, MHC-II expression and IL-6, IL-1β, iNOS and TNF production in myeloid cells. This was accompanied by impaired T cell activation by dendritic cells and inhibition of cytoskeletal rearrangements, thereby reducing macrophage and DC migration. NF-κB signaling was reduced in myeloid cells following ROCK1/2 inhibition. In conclusion, ROCK1/2 inhibition interferes with immune activation at multiple levels and reduces acute GVHD while maintaining GVL-effects, including in corticosteroid-refractory settings.

DOI: https://doi.org/10.1038/s41467-024-44703-7
Blood. 2024 Jan 11. 143(2): 183

Acute leukemia of ambiguous lineage with BCL11B rearrangement.

Yiannis Petros Dimopoulos, Sanam Loghavi.

DOI: https://doi.org/10.1182/blood.2023022709
Cell. 2024 Jan 05. pii: S0092-8674(23)01342-9. [Epub ahead of print]

Hypoxia and intra-complex genetic suppressors rescue complex I mutants by a shared mechanism.

Joshua D Meisel, Maria Miranda, Owen S Skinner, Presli P Wiesenthal, Sandra M Wellner, Alexis A Jourdain, Gary Ruvkun, Vamsi K Mootha.

  The electron transport chain (ETC) of mitochondria, bacteria, and archaea couples electron flow to proton pumping and is adapted to diverse oxygen environments. Remarkably, in mice, neurological disease due to ETC complex I dysfunction is rescued by hypoxia through unknown mechanisms. Here, we show that hypoxia rescue and hyperoxia sensitivity of complex I deficiency are evolutionarily conserved to C. elegans and are specific to mutants that compromise the electron-conducting matrix arm. We show that hypoxia rescue does not involve the hypoxia-inducible factor pathway or attenuation of reactive oxygen species. To discover the mechanism, we use C. elegans genetic screens to identify suppressor mutations in the complex I accessory subunit NDUFA6/nuo-3 that phenocopy hypoxia rescue. We show that NDUFA6/nuo-3(G60D) or hypoxia directly restores complex I forward activity, with downstream rescue of ETC flux and, in some cases, complex I levels. Additional screens identify residues within the ubiquinone binding pocket as being required for the rescue by NDUFA6/nuo-3(G60D) or hypoxia. This reveals oxygen-sensitive coupling between an accessory subunit and the quinone binding pocket of complex I that can restore forward activity in the same manner as hypoxia.

Keywords:  C. elegans; NADH:ubiquinone oxidoreductase; NDUFA6; NDUFS4; complex I; electron transport chain; hyperoxia; hypoxia; mitochondria; oxygen

DOI:  https://doi.org/10.1016/j.cell.2023.12.010
Nat Genet. 2024 Jan 11.

A new genomic framework to categorize pediatric acute myeloid leukemia.

Masayuki Umeda, Jing Ma, Tamara Westover, Yonghui Ni, Guangchun Song, Jamie L Maciaszek, Michael Rusch, Delaram Rahbarinia, Scott Foy, Benjamin J Huang, Michael P Walsh, Priyadarshini Kumar, Yanling Liu, Wenjian Yang, Yiping Fan, Gang Wu, Sharyn D Baker, Xiaotu Ma, Lu Wang, Todd A Alonzo, Jeffrey E Rubnitz, Stanley Pounds, Jeffery M Klco.

Recent studies on pediatric acute myeloid leukemia (pAML) have revealed pediatric-specific driver alterations, many of which are underrepresented in the current classification schemas. To comprehensively define the genomic landscape of pAML, we systematically categorized 887 pAML into 23 mutually distinct molecular categories, including new major entities such as UBTF or BCL11B, covering 91.4% of the cohort. These molecular categories were associated with unique expression profiles and mutational patterns. For instance, molecular categories characterized by specific HOXA or HOXB expression signatures showed distinct mutation patterns of RAS pathway genes, FLT3 or WT1, suggesting shared biological mechanisms. We show that molecular categories were strongly associated with clinical outcomes using two independent cohorts, leading to the establishment of a new prognostic framework for pAML based on these updated molecular categories and minimal residual disease. Together, this comprehensive diagnostic and prognostic framework forms the basis for future classification of pAML and treatment strategies.

DOI: https://doi.org/10.1038/s41588-023-01640-3
Cancer Discov. 2024 Jan 10.

Passenger gene co-amplifications create collateral therapeutic vulnerabilities in cancer.

Yi Bei, Luca Brame, Marieluise Kirchner, Raphaela Fritsche-Guenther, Severine Kunz, Animesh Bhattacharya, Mara-Camelia Rusu, Dennis Gurgen, Frank P B Dubois, Julia K C Koppke, Jutta Proba, Nadine Wittstruck, Olga Alexandra Sidorova, Rocío Chamorro Gonzalez, Heathcliff Dorado Garcia, Lotte Bruckner, Robin Xu, Madalina Giurgiu, Elias Rodriguez-Fos, Qinghao Yu, Bastiaan Spanjaard, Richard P Koche, Clemens A Schmitt, Johannes H Schulte, Angelika Eggert, Kerstin Haase, Jennifer Kirwan, Anja Ih Hagemann, Philipp Mertins, Jan R Dorr, Anton G Henssen.

DNA amplifications in cancer do not only harbor oncogenes. We sought to determine whether passenger co-amplifications could create collateral therapeutic vulnerabilities. Through an analysis of >3,000 cancer genomes followed by the interrogation of CRISPR-Cas9 loss-of-function screens across >700 cancer cell lines, we determined that passenger co-amplifications are accompanied by distinct dependency profiles. In a proof-of-principle study, we demonstrate that co-amplification of the bona fide passenger gene DEAD-Box Helicase 1 (DDX1) creates an increased dependency to the mTOR pathway. Interaction proteomics identified tricarboxylic acid (TCA) cycle components as previously unrecognized DDX1 interaction partners. Live-cell metabolomics highlighted that this interaction could impair TCA activity, which in turn resulted in enhanced mTORC1 activity. Consequently, genetic and pharmacologic disruption of mTORC1 resulted in pronounced cell death in vitro and in vivo. Thus, structurally linked co-amplification of a passenger gene and an oncogene can result in collateral vulnerabilities.

DOI: https://doi.org/10.1158/2159-8290.CD-23-1189
Ann Hematol. 2024 Jan 06.

A blastic plasmacytoid dendritic cell neoplasm-like immunophenotype is negatively associated with CEBPA bZIP mutation and predicts unfavorable prognosis in acute myeloid leukemia.

Juanjuan Song, Weiya Li, Yanliang Bai, Pan Zhou, Junwei Niu, Xiaona Niu, Ying Liu, Xiaobo Liu, Emmanuel Kwateng Drokow, Kai Sun, Hu Zhou.

  Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive myeloid malignancy which characteristically expresses an atypical phenotype including CD123+, CD56+, and CD4+. We are aimed to investigate the clinical and prognostic characteristics of AML patients exhibiting BPDCN-like immunophenotype and provide additional insights for risk stratification of AML. A total of 241 newly diagnosed AML patients were enrolled in this retrospective study and categorized into BPDCN-like positive (n = 125)/negative (n = 116) groups, determined by the present with CD123+ along with either CD56+ or CD4+, or both. Subsequently, an analysis was conducted to examine the general clinical characteristics, genetic profiles, and prognosis of the two respective groups. Patients with BPDCN-like immunophenotype manifested higher frequencies of acute myelomonocytic leukemia and acute monoblastic leukemia. Surprisingly, the presence of the BPDCN-like immunophenotype exhibited an inverse relationship with CEBPA bZIP mutation. Notably, patients with BPDCN-like phenotype had both worse OS and EFS compared to those without BPDCN-like phenotype. In the CN-AML subgroups, the BPDCN-like phenotype was associated with worse EFS. Similarly, a statistically significant disparity was observed in both OS and EFS within the favorable-risk subgroup, while only OS was significant within the adverse-risk subgrouMoreover, patients possessing favorable-risk genetics without BPDCN-like phenotype had the longest survival, whereas those who had both adverse-risk genetics and BPDCN-like phenotype exhibited the worst survival. Our study indicated that BPDCN-like phenotype negatively associated with CEBPA bZIP mutation and revealed a significantly poor prognosis in AML. Moreover, the 2022 ELN classification, in combination with the BPDCN-like phenotype, may better distinguish between different risk groups.

Keywords:  Acute myeloid leukemia; Blastic plasmacytoid dendritic cell neoplasm-like immunophenotype; CEBPA mutation; Prognosis; Risk classification

DOI:  https://doi.org/10.1007/s00277-023-05594-8