bims-tremyl 2023-03-12 papers

bims-tremyl

Biomed News

on Therapy resistance biology in myeloid leukemia

Issue of 2023–03–12
33 papers selected by
Paolo Gallipoli, Barts Cancer Institute, Queen Mary University of London

Undetectable Measurable Residual Disease is Associated with Improved Outcomes in AML Irrespective of Treatment Intensity.
Combinatorial BCL-2 family expression in Acute Myeloid Leukemia Stem Cells predicts clinical response to Azacitidine/Venetoclax.
Detection and targeting of splicing deregulation in pediatric acute myeloid leukemia stem cells.
Molecularly Targeted Therapy in Acute Myeloid Leukemia: Current Treatment Landscape and Mechanisms of Response and Resistance.
Early mortality in acute myeloid leukemia with KMT2A rearrangement is associated with high risk of bleeding and disseminated intravascular coagulation.
Defining clonal hematopoiesis of indeterminate potential: evolutionary dynamics and detection under aging and inflammation.
The occurrence of thrombosis during intensive chemotherapy treatment for acute myeloid leukemia patients does not impact on long-term survival.
Dual IKZF2 and CK1α degrader targets acute myeloid leukemia cells.
MANIFEST: Pelabresib in Combination With Ruxolitinib for Janus Kinase Inhibitor Treatment-Naïve Myelofibrosis.
DNA Sequencing to Detect Residual Disease in Adults With Acute Myeloid Leukemia Prior to Hematopoietic Cell Transplant.
Longitudinal single-cell profiling of chemotherapy response in acute myeloid leukemia.
Magrolimab in Combination With Azacitidine in Patients With Higher-Risk Myelodysplastic Syndromes: Final Results of a Phase Ib Study.
Association between bariatric surgery and outcomes in chronic myeloid leukemia.
Mitochondrial redox adaptations enable alternative aspartate synthesis in SDH-deficient cells.
RUNX1::ETO translocations must precede CSF3R mutations to promote acute myeloid leukemia development.
The CKS1/CKS2 Proteostasis Axis Is Crucial to Maintain Hematopoietic Stem Cell Function.
Treatment outcomes for newly diagnosed, treatment-naïve TP53-mutated acute myeloid leukemia: a systematic review and meta-analysis.
Primary Cancer Matters in Therapy-related Myeloid Neoplasm Patients Receiving Allogeneic Hematopoietic Cell Transplantation: A Study From the Chronic Malignancies Working Party of the EBMT.
Poor post-induction outcomes in patients with acute myeloid leukemia previously treated with hypomethylating agents.
Spectrum of renal pathological findings in patients with chronic myelomonocytic leukemia and kidney injury.
Targeting HDAC3 to overcome the resistance to ATRA or arsenic in acute promyelocytic leukemia through ubiquitination and degradation of PML-RARα.
Patient-guided dose reduction of tyrosine kinase inhibitors in chronic myeloid leukaemia (RODEO study): study protocol for a prospective, multicentre, single-arm trial.
Real-World Experience of Adults With Acute Myeloid Leukemia on Hypomethylating Agents With or Without Venetoclax at a Comprehensive Cancer Center.
Prospective Validation of the Prognostic Relevance of CD34+CD38- AML Stem Cell frequency in the HOVON-SAKK132 trial.
Feasibility, safety, and efficacy of early prophylactic donor lymphocyte infusion after T cell-depleted allogeneic stem cell transplantation in acute leukemia patients.
The International Consensus Classification of Acute Leukemias of Ambiguous Lineage.
Immune selection determines tumor antigenicity and influences response to checkpoint inhibitors.
Altered DNA repair pathway engagement by engineered CRISPR-Cas9 nucleases.
Fumarate induces vesicular release of mtDNA to drive innate immunity.
Macrophage fumarate hydratase restrains mtRNA-mediated interferon production.
Nucleophosmin plays a role in repairing DNA damage and is a target for cancer treatment.
Plasma cell derived mtDAMPs activate macrophage STING pathway which promotes myeloma progression.
Identification of phenotypically, functionally, and anatomically distinct stromal niche populations in human bone marrow based on single-cell RNA sequencing.

Blood Adv. 2023 Mar 08. pii: bloodadvances.2022009391. [Epub ahead of print]

Undetectable Measurable Residual Disease is Associated with Improved Outcomes in AML Irrespective of Treatment Intensity.

Alexandre Bazinet, Tapan M Kadia, Nicholas J Short, Gautam Borthakur, Sa A Wang, Wei Wang, Sanam Loghavi, Jeffrey L Jorgensen, Keyur P Patel, Courtney D DiNardo, Naval G Daver, Yesid Alvarado, Fadi G Haddad, Sherry R Pierce, Graciela M Nogueras Gonzalez, Abhishek Maiti, Koji Sasaki, Musa Yilmaz, Philip A Thompson, William G Wierda, Guillermo Garcia-Manero, Michael Andreeff, Elias J Jabbour, Marina Y Konopleva, Xuelin Huang, Hagop M Kantarjian, Farhad Ravandi.

Acute myeloid leukemia (AML) can be treated with either high or low-intensity regimens. Highly sensitive assays for measurable residual disease (MRD) now allow for a more precise assessment of response quality. We hypothesized that treatment intensity may not be a key predictor of outcomes assuming an optimal response to therapy is achieved. We performed a single-center retrospective study including 635 patients with newly diagnosed AML responding to either intensive cytarabine/anthracycline-based chemotherapy (IA, n=385) or low-intensity venetoclax-based regimens (LOW + VEN, n=250) and who had adequate flow cytometry-based MRD testing performed at the time of best response. The median overall survival (OS) was 50.2, 18.2, 13.6, and 8.1 months for the IA MRD(-), LOW + VEN MRD(-), IA MRD(+), and LOW + VEN MRD(+) cohorts, respectively. The 2-year cumulative incidence of relapse (CIR) was 41.1%, 33.5%, 64.2%, and 59.9% for the IA MRD(-), LOW + VEN MRD(-), IA MRD(+), and LOW + VEN MRD(+) cohorts, respectively. The CIR was similar between patients within MRD categories irrespective of the treatment regimen received. The IA cohort was enriched for younger patients and more favorable AML cytogenetic/molecular categories. By multivariate analysis (MVA), age, best response (CR/CRi/MLFS), MRD status, and ELN 2017 risk remained significantly associated with OS, whereas best response, MRD status, and ELN 2017 risk were significantly associated with CIR. Treatment intensity was not significantly associated with either OS or CIR. Achievement of MRD-negative complete remission should be the key objective of AML therapy in both high- and low-intensity treatment regimens.

DOI: https://doi.org/10.1182/bloodadvances.2022009391
Cancer Discov. 2023 Mar 09. pii: CD-22-0939. [Epub ahead of print]

Combinatorial BCL-2 family expression in Acute Myeloid Leukemia Stem Cells predicts clinical response to Azacitidine/Venetoclax.

Alexander Waclawiczek, Aino-Maija Leppa, Simon Renders, Karolin Stumpf, Cecilia Reyneri, Barbara Betz, Maike Janssen, Rabia Shahswar, Elisa Donato, Darja Karpova, Vera Thiel, Julia M Unglaub, Susanna Grabowski, Stefanie Gryzik, Lisa Vierbaum, Richard F Schlenk, Christoph Rollig, Michael Hundemer, Caroline Pabst, Michael Heuser, Simon Raffel, Carsten Muller-Tidow, Tim Sauer, Andreas Trumpp.

The BCL-2 inhibitor Venetoclax (VEN) in combination with Azacitidine (5-AZA) is currently transforming Acute Myeloid Leukemia (AML) therapy. However, there is a lack of clinically relevant biomarkers that predict response to 5-AZA/VEN. Here, we integrated transcriptomic, proteomic, functional and clinical data to identify predictors of 5-AZA/VEN response. Although cultured monocytic AML cells displayed upfront resistance, monocytic differentiation was not clinically predictive in our patient cohort. We identified leukemic stem cells (LSC) as primary targets of 5-AZA/VEN whose elimination determined therapy outcome. LSCs of 5-AZA/VEN refractory patients displayed perturbed apoptotic dependencies. We developed and validated a flow cytometry-based "Mediators-of-Apoptosis-Combinatorial-Score" (MAC-Score) linking the ratio of protein expression of BCL-2, BCL-xL, and MCL-1 in LSCs. MAC-Scoring predicts initial response with a positive predictive-value of >97% associated to increased event-free survival. In summary, combinatorial levels of BCL-2-family members in AML-LSCs are a key denominator of response and MAC-Scoring reliably predicts patient response to 5-AZA/VEN.

DOI: https://doi.org/10.1158/2159-8290.CD-22-0939
Cell Rep Med. 2023 Mar 02. pii: S2666-3791(23)00054-X. [Epub ahead of print] 100962

Detection and targeting of splicing deregulation in pediatric acute myeloid leukemia stem cells.

Inge van der Werf, Phoebe K Mondala, S Kathleen Steel, Larisa Balaian, Luisa Ladel, Cayla N Mason, Raymond H Diep, Jessica Pham, Jacqueline Cloos, Gertjan J L Kaspers, Warren C Chan, Adam Mark, James J La Clair, Peggy Wentworth, Kathleen M Fisch, Leslie A Crews, Thomas C Whisenant, Michael D Burkart, Mary E Donohoe, Catriona H M Jamieson.

  Pediatric acute myeloid leukemia (pAML) is typified by high relapse rates and a relative paucity of somatic DNA mutations. Although seminal studies show that splicing factor mutations and mis-splicing fuel therapy-resistant leukemia stem cell (LSC) generation in adults, splicing deregulation has not been extensively studied in pAML. Herein, we describe single-cell proteogenomics analyses, transcriptome-wide analyses of FACS-purified hematopoietic stem and progenitor cells followed by differential splicing analyses, dual-fluorescence lentiviral splicing reporter assays, and the potential of a selective splicing modulator, Rebecsinib, in pAML. Using these methods, we discover transcriptomic splicing deregulation typified by differential exon usage. In addition, we discover downregulation of splicing regulator RBFOX2 and CD47 splice isoform upregulation. Importantly, splicing deregulation in pAML induces a therapeutic vulnerability to Rebecsinib in survival, self-renewal, and lentiviral splicing reporter assays. Taken together, the detection and targeting of splicing deregulation represent a potentially clinically tractable strategy for pAML therapy.

Keywords:  CD47; RBFOX2; SF3B1; embryonic stem cells; hematopoietic stem cells; pediatric AML; pre-mRNA splicing; splicing modulation

DOI:  https://doi.org/10.1016/j.xcrm.2023.100962
Cancers (Basel). 2023 Mar 06. pii: 1617. [Epub ahead of print]15(5):

Molecularly Targeted Therapy in Acute Myeloid Leukemia: Current Treatment Landscape and Mechanisms of Response and Resistance.

Curtis A Lachowiez, Courtney D DiNardo, Sanam Loghavi.

  Treatment for acute myeloid leukemia (AML) has evolved rapidly over the last decade as improved understanding of cytogenetic and molecular drivers of leukemogenesis refined survival prognostication and enabled development of targeted therapeutics. Molecularly targeted therapies are now approved for the treatment of FLT3 and IDH1/2-mutated AML and additional molecularly and cellularly targeted therapeutics are in development for defined patient subgroups. Alongside these welcome therapeutic advancements, increased understanding of leukemic biology and treatment resistance has resulted in clinical trials investigating combinations of cytotoxic, cellular, and molecularly targeted therapeutics resulting in improved response and survival outcomes in patients with AML. Herein, we comprehensively review the current landscape of IDH and FLT3 inhibitors in clinical practice for the treatment of AML, highlight known resistance mechanisms, and discuss new cellular or molecularly targeted therapies currently under investigation in ongoing early phase clinical trials.

Keywords:  FLT3 inhibitor; IDH inhibitor; acute myeloid leukemia; targeted therapy

DOI:  https://doi.org/10.3390/cancers15051617
Cancer. 2023 Mar 09.

Early mortality in acute myeloid leukemia with KMT2A rearrangement is associated with high risk of bleeding and disseminated intravascular coagulation.

Daniel Nguyen, Hagop M Kantarjian, Nicholas J Short, Wei Qiao, Jing Ning, Branko Cuglievan, Naval G Daver, Courtney D DiNardo, Elias J Jabbour, Tapan M Kadia, Gautam Borthakur, Guillermo Garcia-Manero, Marina Y Konopleva, Michael Andreeff, Farhad Ravandi-Kashani, Koji Sasaki, Ghayas C Issa.

   BACKGROUND: Acute myeloid leukemia (AML) with rearrangement of lysine methyltransferase 2a gene (KMT2Ar) is characterized by chemotherapy resistance and high rates of relapse. However, additional causes of treatment failure or early mortality have not been well-defined in this entity.
METHODS: In a retrospective analysis, causes and rates of early mortality following induction treatment were compared between a cohort of adults with KMT2Ar AML (N = 172) and an age-matched cohort of patients with normal karyotype AML (N = 522).
RESULTS: The 60-day mortality in patients with KMT2Ar AML was 15% compared with 7% with normal karyotype (p = .04). We found a significantly higher occurrence of major bleeding events (p = .005) and total bleeding events (p = .001) in KMT2Ar AML compared with diploid AML. Among evaluable patients with KMT2Ar AML, 93% exhibited overt disseminated intravascular coagulopathy compared with 54% of patients with a normal karyotype before death (p = .03). In a multivariate analysis, KMT2Ar and a monocytic phenotypic were the only independent predictors of any bleeding event in patients who died within 60 days (odds ratio, 3.5; 95% CI, 1.4-10.4; p = .03; odds ratio, 3.2; 95% CI, 1-1-9.4; p = .04, respectively).
CONCLUSION: In conclusion, early recognition and aggressive management of disseminated intravascular coagulopathy and coagulopathy are important considerations that could mitigate the risk of death during induction treatment in KMT2Ar AML.
PLAIN LANGUAGE SUMMARY: Acute myeloid leukemia (AML) with rearrangement of KMT2A is characterized by chemotherapy resistance and high rates of relapse. However, additional causes of treatment failure or early mortality have not been well-defined in this entity. In this article, that KMT2A-rearranged AML is demonstrably associated with higher early mortality and an increased risk of bleeding and coagulopathy, specifically, disseminated intravascular coagulation, compared with normal karyotype AML. These findings emphasize the importance of monitoring and mitigating coagulopathy in KMT2A-rearranged leukemia similar to what is done in acute promyelocytic leukemia.

Keywords:  AML; APL; DIC; KMT2A; MLL; bleeding; early mortality

DOI:  https://doi.org/10.1002/cncr.34728
Cold Spring Harb Mol Case Stud. 2023 Mar 08. pii: mcs.a006251. [Epub ahead of print]

Defining clonal hematopoiesis of indeterminate potential: evolutionary dynamics and detection under aging and inflammation.

Elisabeth Aline Goldman, Paul T Spellman, Anupriya Agarwal.

  Clonal hematopoiesis (CH), where hematopoietic stem and progenitor cell (HSPC) clones and their progeny expand in the circulating blood cell population, occurs following the acquisition of somatic driver mutations. Individuals diagnosed with clonal hematopoiesis of indeterminate potential (CHIP) carry somatic mutations in hematological malignancy-associated driver genes, historically at or above a variant allele frequency of 2%, but do not exhibit abnormal blood cell counts or any other symptoms of hematologic disease. However, CHIP is associated with moderately increased risk of hematological cancer, and a greater likelihood of cardiovascular and pulmonary disease. Recent advances in the resolution of high-throughput sequencing experiments suggest CHIP is much more prevalent in the population than once thought, particularly among those aged 60 and over. While CHIP does elevate the risk of eventual hematological malignancy, only one in ten individuals with CHIP will receive such a diagnosis; the problem lies in the continued difficulty in accurately separating the 10% of CHIP patients who are most likely to be in a pre-malignant state from those who are not, given the heterogeneity of this condition and the etiology of the associated hematological cancers. Concerns over the risk of eventual malignancies must be balanced with growing recognition of CH as common age-dependent occurrence, and efforts to better characterize and differentiate oncogenic clonal expansion from that which is much more benign. In this review, we discuss evolutionary dynamics of CH and CHIP, the relationship of CH to aging and inflammation, and the role of the epigenome in promoting potentially pathogenic or benign cellular trajectories. We outline molecular mechanisms that may contribute to heterogeneity in the etiology of CHIP and incidence of malignant disease among individuals. Finally, we discuss epigenetic markers and modifications for CHIP detection and monitoring with potential for translational applications and clinical utility in the near future.

Keywords:  Acute myeloid leukemia; Hematological neoplasm

DOI:  https://doi.org/10.1101/mcs.a006251
Ann Hematol. 2023 Mar 11.

The occurrence of thrombosis during intensive chemotherapy treatment for acute myeloid leukemia patients does not impact on long-term survival.

Tamer Hellou, Omri Cohen, Abraham Avigdor, Irina Amitai, Avichai Shimoni, Mudi Misgav, Jonathan Canaani.

  Venous thromboembolism (VTE) is frequently seen in acute myeloid leukemia (AML) patients and presents a significant clinical challenge. The association of VTE during intensive chemotherapy with risk models such as the Medical Research Council (MRC) cytogenetic-based assessment and the European LeukemiaNet (ELN) 2017 molecular risk model have not been rigorously evaluated. Additionally, there is a paucity of data pertaining to the long-term prognostic impact of VTE in AML patients. We performed an analysis of baseline parameters of AML patients diagnosed with VTE during intensive chemotherapy and compared them with patients without VTE. The analyzed cohort consisted of 335 newly diagnosed AML patients with a median age of 55 years. Thirty-five patients (11%) were classified as MRC favorable risk, 219 (66%) patients as intermediate risk, 58 patients (17%) as adverse risk. Per ELN 2017, 132 patients (40%) had favorable risk disease, 122 patients (36%) intermediate risk, and 80 patients (24%) had adverse risk. VTE was seen in 33 patients (9.9%), occurring mostly during induction (70%), and required catheter removal in 9 patients (28%). Baseline clinical, laboratory, molecular, and ELN 2017 parameters were not significantly different groups. However, MRC intermediate-risk group patients were significantly more likely to experience thrombosis compared to favorable risk and adverse risk patients (12.8% versus 5.7% and 1.7%, respectively; p = 0.049). Median overall survival was not significantly impacted by the diagnosis of thrombosis (3.7 years versus 2.2 years; p = 0.47). VTE is tightly associated with temporal and cytogenetic parameters in AML but does not significantly impact on long-term outcomes.

Keywords:  Acute myeloid leukemia; Chemotherapy; Survival; Venous thromboembolism

DOI:  https://doi.org/10.1007/s00277-023-05158-w
Cancer Cell. 2023 Feb 28. pii: S1535-6108(23)00038-7. [Epub ahead of print]

Dual IKZF2 and CK1α degrader targets acute myeloid leukemia cells.

Sun-Mi Park, David K Miyamoto, Grace Y Q Han, Mandy Chan, Nicole M Curnutt, Nathan L Tran, Anthony Velleca, Jun Hyun Kim, Alexandra Schurer, Kathryn Chang, Wenqing Xu, Michael G Kharas, Christina M Woo.

  Acute myeloid leukemia (AML) is a hematologic malignancy for which several epigenetic regulators have been identified as therapeutic targets. Here we report the development of cereblon-dependent degraders of IKZF2 and casein kinase 1α (CK1α), termed DEG-35 and DEG-77. We utilized a structure-guided approach to develop DEG-35 as a nanomolar degrader of IKZF2, a hematopoietic-specific transcription factor that contributes to myeloid leukemogenesis. DEG-35 possesses additional substrate specificity for the therapeutically relevant target CK1α, which was identified through unbiased proteomics and a PRISM screen assay. Degradation of IKZF2 and CK1α blocks cell growth and induces myeloid differentiation in AML cells through CK1α-p53- and IKZF2-dependent pathways. Target degradation by DEG-35 or a more soluble analog, DEG-77, delays leukemia progression in murine and human AML mouse models. Overall, we provide a strategy for multitargeted degradation of IKZF2 and CK1α to enhance efficacy against AML that may be expanded to additional targets and indications.

Keywords:  IKZF2; acute myeloid leukemia; casein kinase 1 alpha; cereblon; targeted protein degradation

DOI:  https://doi.org/10.1016/j.ccell.2023.02.010
J Clin Oncol. 2023 Mar 07. JCO2201972

MANIFEST: Pelabresib in Combination With Ruxolitinib for Janus Kinase Inhibitor Treatment-Naïve Myelofibrosis.

John Mascarenhas, Marina Kremyanskaya, Andrea Patriarca, Francesca Palandri, Timothy Devos, Francesco Passamonti, Raajit K Rampal, Adam J Mead, Gabriella Hobbs, Joseph M Scandura, Moshe Talpaz, Nikki Granacher, Tim C P Somervaille, Ronald Hoffman, Marielle J Wondergem, Mohamed E Salama, Gozde Colak, Jike Cui, Jean-Jacques Kiladjian, Alessandro M Vannucchi, Srdan Verstovsek, Natalia Curto-García, Claire Harrison, Vikas Gupta.

PURPOSE: Standard therapy for myelofibrosis comprises Janus kinase inhibitors (JAKis), yet spleen response rates of 30%-40%, high discontinuation rates, and a lack of disease modification highlight an unmet need. Pelabresib (CPI-0610) is an investigational, selective oral bromodomain and extraterminal domain inhibitor (BETi).
METHODS: MANIFEST (ClinicalTrails.gov identifier: NCT02158858), a global, open-label, nonrandomized, multicohort, phase II study, includes a cohort of JAKi-naïve patients with myelofibrosis treated with pelabresib and ruxolitinib. The primary end point is a spleen volume reduction of ≥ 35% (SVR35) at 24 weeks.
RESULTS: Eighty-four patients received ≥ 1 dose of pelabresib and ruxolitinib. The median age was 68 (range, 37-85) years; 24% of patients were intermediate-1 risk, 61% were intermediate-2 risk, and 16% were high risk as per the Dynamic International Prognostic Scoring System; 66% (55 of 84) of patients had a hemoglobin level of < 10 g/dL at baseline. At 24 weeks, 68% (57 of 84) achieved SVR35, and 56% (46 of 82) achieved a total symptom score reduction of ≥ 50% (TSS50). Additional benefits at week 24 included 36% (29 of 84) of patients with improved hemoglobin levels (mean, 1.3 g/dL; median, 0.8 g/dL), 28% (16 of 57) with ≥ 1 grade improvement in fibrosis, and 29.5% (13 of 44) with > 25% reduction in JAK2V617F-mutant allele fraction, which was associated with SVR35 response (P = .018, Fisher's exact test). At 48 weeks, 60% (47 of 79) of patients had SVR35 response. Grade 3 or 4 toxicities seen in ≥ 10% patients were thrombocytopenia (12%) and anemia (35%), leading to treatment discontinuation in three patients. 95% (80 of 84) of the study participants continued combination therapy beyond 24 weeks.
CONCLUSION: The rational combination of the BETi pelabresib and ruxolitinib in JAKi-naïve patients with myelofibrosis was well tolerated and showed durable improvements in spleen and symptom burden, with associated biomarker findings of potential disease-modifying activity.

DOI: https://doi.org/10.1200/JCO.22.01972
JAMA. 2023 03 07. 329(9): 745-755

DNA Sequencing to Detect Residual Disease in Adults With Acute Myeloid Leukemia Prior to Hematopoietic Cell Transplant.

Laura W Dillon, Gege Gui, Kristin M Page, Niveditha Ravindra, Zoë C Wong, Georgia Andrew, Devdeep Mukherjee, Scott L Zeger, Firas El Chaer, Stephen Spellman, Alan Howard, Karen Chen, Jeffery Auletta, Steven M Devine, Antonio Martin Jimenez Jimenez, Marcos J G De Lima, Mark R Litzow, Partow Kebriaei, Wael Saber, Daniel J Weisdorf, Christopher S Hourigan.

Importance: Preventing relapse for adults with acute myeloid leukemia (AML) in first remission is the most common indication for allogeneic hematopoietic cell transplant. The presence of AML measurable residual disease (MRD) has been associated with higher relapse rates, but testing is not standardized.
Objective: To determine whether DNA sequencing to identify residual variants in the blood of adults with AML in first remission before allogeneic hematopoietic cell transplant identifies patients at increased risk of relapse and poorer overall survival compared with those without these DNA variants.
Design, Setting, and Participants: In this retrospective observational study, DNA sequencing was performed on pretransplant blood from patients aged 18 years or older who had undergone their first allogeneic hematopoietic cell transplant during first remission for AML associated with variants in FLT3, NPM1, IDH1, IDH2, or KIT at 1 of 111 treatment sites from 2013 through 2019. Clinical data were collected, through May 2022, by the Center for International Blood and Marrow Transplant Research.
Exposure: Centralized DNA sequencing of banked pretransplant remission blood samples.
Main Outcomes and Measures: The primary outcomes were overall survival and relapse. Day of transplant was considered day 0. Hazard ratios were reported using Cox proportional hazards regression models.
Results: Of 1075 patients tested, 822 had FLT3 internal tandem duplication (FLT3-ITD) and/or NPM1 mutated AML (median age, 57.1 years, 54% female). Among 371 patients in the discovery cohort, the persistence of NPM1 and/or FLT3-ITD variants in the blood of 64 patients (17.3%) in remission before undergoing transplant was associated with worse outcomes after transplant (2013-2017). Similarly, of the 451 patients in the validation cohort who had undergone transplant in 2018-2019, 78 patients (17.3%) with residual NPM1 and/or FLT3-ITD variants had higher rates of relapse at 3 years (68% vs 21%; difference, 47% [95% CI, 26% to 69%]; HR, 4.32 [95% CI, 2.98 to 6.26]; P < .001) and decreased survival at 3 years (39% vs 63%; difference, -24% [2-sided 95% CI, -39% to -9%]; HR, 2.43 [95% CI, 1.71 to 3.45]; P < .001).
Conclusions and Relevance: Among patients with acute myeloid leukemia in first remission prior to allogeneic hematopoietic cell transplant, the persistence of FLT3 internal tandem duplication or NPM1 variants in the blood at an allele fraction of 0.01% or higher was associated with increased relapse and worse survival compared with those without these variants. Further study is needed to determine whether routine DNA-sequencing testing for residual variants can improve outcomes for patients with acute myeloid leukemia.

DOI: https://doi.org/10.1001/jama.2023.1363
Nat Commun. 2023 Mar 08. 14(1): 1285

Longitudinal single-cell profiling of chemotherapy response in acute myeloid leukemia.

Matteo Maria Naldini, Gabriele Casirati, Matteo Barcella, Paola Maria Vittoria Rancoita, Andrea Cosentino, Carolina Caserta, Francesca Pavesi, Erika Zonari, Giacomo Desantis, Diego Gilioli, Matteo Giovanni Carrabba, Luca Vago, Massimo Bernardi, Raffaella Di Micco, Clelia Di Serio, Ivan Merelli, Monica Volpin, Eugenio Montini, Fabio Ciceri, Bernhard Gentner.

Acute myeloid leukemia may be characterized by a fraction of leukemia stem cells (LSCs) that sustain disease propagation eventually leading to relapse. Yet, the contribution of LSCs to early therapy resistance and AML regeneration remains controversial. We prospectively identify LSCs in AML patients and xenografts by single-cell RNA sequencing coupled with functional validation by a microRNA-126 reporter enriching for LSCs. Through nucleophosmin 1 (NPM1) mutation calling or chromosomal monosomy detection in single-cell transcriptomes, we discriminate LSCs from regenerating hematopoiesis, and assess their longitudinal response to chemotherapy. Chemotherapy induced a generalized inflammatory and senescence-associated response. Moreover, we observe heterogeneity within progenitor AML cells, some of which proliferate and differentiate with expression of oxidative-phosphorylation (OxPhos) signatures, while others are OxPhos (low) miR-126 (high) and display enforced stemness and quiescence features. miR-126 (high) LSCs are enriched at diagnosis in chemotherapy-refractory AML and at relapse, and their transcriptional signature robustly stratifies patients for survival in large AML cohorts.

DOI: https://doi.org/10.1038/s41467-023-36969-0
J Clin Oncol. 2023 Mar 08. JCO2201794

Magrolimab in Combination With Azacitidine in Patients With Higher-Risk Myelodysplastic Syndromes: Final Results of a Phase Ib Study.

David A Sallman, Monzr M Al Malki, Adam S Asch, Eunice S Wang, Joseph G Jurcic, Terrence J Bradley, Ian W Flinn, Daniel A Pollyea, Suman Kambhampati, Tiffany N Tanaka, Joshua F Zeidner, Guillermo Garcia-Manero, Deepa Jeyakumar, Rami Komrokji, Jeffrey Lancet, Hagop M Kantarjian, Lin Gu, Yajia Zhang, Anderson Tan, Mark Chao, Carol O'Hear, Giridharan Ramsingh, Indu Lal, Paresh Vyas, Naval G Daver.

PURPOSE: Magrolimab is a monoclonal antibody that blocks cluster of differentiation 47, a don't-eat-me signal overexpressed on cancer cells. Cluster of differentiation 47 blockade by magrolimab promotes macrophage-mediated phagocytosis of tumor cells and is synergistic with azacitidine, which increases expression of eat-me signals. We report final phase Ib data in patients with untreated higher-risk myelodysplastic syndromes (MDS) treated with magrolimab and azacitidine (NCT03248479).
PATIENTS AND METHODS: Patients with previously untreated Revised International Prognostic Scoring System intermediate-/high-/very high-risk MDS received magrolimab intravenously as a priming dose (1 mg/kg) followed by ramp-up to a 30 mg/kg once-weekly or once-every-2-week maintenance dose. Azacitidine 75 mg/m2 was administered intravenously/subcutaneously once daily on days 1-7 of each 28-day cycle. Primary end points were safety/tolerability and complete remission (CR) rate.
RESULTS: Ninety-five patients were treated. Revised International Prognostic Scoring System risk was intermediate/high/very high in 27%, 52%, and 21%, respectively. Fifty-nine (62%) had poor-risk cytogenetics and 25 (26%) had TP53 mutation. The most common treatment-emergent adverse effects included constipation (68%), thrombocytopenia (55%), and anemia (52%). Median hemoglobin change from baseline to first postdose assessment was -0.7 g/dL (range: -3.1 to +2.4). CR rate and overall response rate were 33% and 75%, respectively. Median time to response, duration of CR, duration of overall response, and progression-free survival were 1.9, 11.1, 9.8, and 11.6 months, respectively. Median overall survival (OS) was not reached with 17.1-month follow-up. In TP53-mutant patients, 40% achieved CR with median OS of 16.3 months. Thirty-four patients (36%) had allogeneic stem-cell transplant with 77% 2-year OS.
CONCLUSION: Magrolimab + azacitidine was well tolerated with promising efficacy in patients with untreated higher-risk MDS, including those with TP53 mutations. A phase III trial of magrolimab/placebo + azacitidine is ongoing (ENHANCE: NCT04313881).

DOI: https://doi.org/10.1200/JCO.22.01794
Cancer. 2023 Mar 07.

Association between bariatric surgery and outcomes in chronic myeloid leukemia.

Fadi G Haddad, Hagop M Kantarjian, Aram Bidikian, Elias J Jabbour, Nicholas J Short, Jing Ning, Lianchun Xiao, Naveen Pemmaraju, Courtney D DiNardo, Tapan M Kadia, Kayleigh R Marx, Guillermo Garcia-Manero, Farhad Ravandi, Koji Sasaki, Ghayas C Issa.

   BACKGROUND: Bariatric surgery is the most effective weight loss intervention. However, it can also decrease the bioavailability of oral medications. Tyrosine kinase inhibitors, the mainstay treatment for chronic myeloid leukemia (CML), are the most successful example of an oral targeted therapy. The impact of bariatric surgery on CML outcomes is unknown.
METHODS: In a retrospective analysis, we screened 652 patients with CML and identified 22 with prior bariatric surgery, and compared their outcomes to a matched cohort of 44 patients with no prior bariatric surgery.
RESULTS: The rate of early molecular response (3-month BCR::ABL1 < 10% International Scale) was lower in the bariatric surgery group compared with the control group (68% vs. 91%; p = .05), with longer median times to achieve complete cytogenetic (6 vs. 3 months; p = .001) or major molecular responses (12 vs. 6 months; p = .001). Bariatric surgery was associated with inferior event-free survival (5-year, 60% vs. 77%; p = .004) and failure-free survival (5-year, 32% vs. 63%; p < .0001). In a multivariate analysis, bariatric surgery was the only independent predictor for the risk of treatment failure (hazard ratio, 9.40; 95% CI, 2.71-32.55; p = .0004) or event-free survival (hazard ratio, 4.24; 95% CI, 1.67-12.23; p = .008).
CONCLUSIONS: Bariatric surgery is associated with suboptimal responses that require adapted treatment strategies.

Keywords:  bariatric surgery; chronic myeloid leukemia; obesity; response; survival; tyrosine kinase inhibitors

DOI:  https://doi.org/10.1002/cncr.34725
Elife. 2023 Mar 08. pii: e78654. [Epub ahead of print]12

Mitochondrial redox adaptations enable alternative aspartate synthesis in SDH-deficient cells.

Madeleine L Hart, Evan Quon, Anna-Lena B G Vigil, Ian A Engstrom, Oliver J Newsom, Kristian Davidsen, Pia Hoellerbauer, Samantha M Carlisle, Lucas B Sullivan.

  The oxidative tricarboxylic acid (TCA) cycle is a central mitochondrial pathway integrating catabolic conversions of NAD+ to NADH and anabolic production of aspartate, a key amino acid for cell proliferation. Several TCA cycle components are implicated in tumorigenesis, including loss of function mutations in subunits of succinate dehydrogenase (SDH), also known as complex II of the electron transport chain (ETC), but mechanistic understanding of how proliferating cells tolerate the metabolic defects of SDH loss is still lacking. Here, we identify that SDH supports human cell proliferation through aspartate synthesis but, unlike other ETC impairments, the effects of SDH inhibition are not ameliorated by electron acceptor supplementation. Interestingly, we find aspartate production and cell proliferation are restored to SDH-impaired cells by concomitant inhibition of ETC complex I (CI). We determine that the benefits of CI inhibition in this context depend on decreasing mitochondrial NAD+/NADH, which drives SDH-independent aspartate production through pyruvate carboxylation and reductive carboxylation of glutamine. We also find that genetic loss or restoration of SDH selects for cells with concordant CI activity, establishing distinct modalities of mitochondrial metabolism for maintaining aspartate synthesis. These data therefore identify a metabolically beneficial mechanism for CI loss in proliferating cells and reveal how compartmentalized redox changes can impact cellular fitness.

Keywords:  biochemistry; cancer biology; chemical biology; human

DOI:  https://doi.org/10.7554/eLife.78654
Leukemia. 2023 Mar 09.

RUNX1::ETO translocations must precede CSF3R mutations to promote acute myeloid leukemia development.

Sarah A Carratt, Garth L Kong, Cody Coblentz, Zachary Schonrock, Lauren Maloney, Ben Weeder, Will Yashar, Rowan Callahan, Hunter Blaylock, Colin Coleman, Dan Coleman, Theodore P Braun, Julia E Maxson.

DOI: https://doi.org/10.1038/s41375-023-01862-8
Hemasphere. 2023 Mar;7(3): e853

The CKS1/CKS2 Proteostasis Axis Is Crucial to Maintain Hematopoietic Stem Cell Function.

William Grey, Samantha Atkinson, Beatrice Rix, Pedro Casado, Linda Ariza-McNaughton, Cathy Hawley, Miriam L Sopoena, Katherine S Bridge, David Kent, Pedro R Cutillas, Dominique Bonnet.

Long-term hematopoietic stem cells are rare, highly quiescent stem cells of the hematopoietic system with life-long self-renewal potential and the ability to transplant and reconstitute the entire hematopoietic system of conditioned recipients. Most of our understanding of these rare cells has relied on cell surface identification, epigenetic, and transcriptomic analyses. Our knowledge of protein synthesis, folding, modification, and degradation-broadly termed protein homeostasis or "proteostasis"-in these cells is still in its infancy, with very little known about how the functional state of the proteome is maintained in hematopoietic stem cells. We investigated the requirement of the small phospho-binding adaptor proteins, the cyclin-dependent kinase subunits (CKS1 and CKS2), for maintaining ordered hematopoiesis and long-term hematopoietic stem cell reconstitution. CKS1 and CKS2 are best known for their roles in p27 degradation and cell cycle regulation, and by studying the transcriptome and proteome of Cks1 -/- and Cks2 -/- mice, we demonstrate regulation of key signaling pathways that govern hematopoietic stem cell biology including AKT, FOXO1, and NFκB, together balancing protein homeostasis and restraining reactive oxygen species to ensure healthy hematopoietic stem cell function.

DOI: https://doi.org/10.1097/HS9.0000000000000853
J Hematol Oncol. 2023 Mar 06. 16(1): 19

Treatment outcomes for newly diagnosed, treatment-naïve TP53-mutated acute myeloid leukemia: a systematic review and meta-analysis.

Naval G Daver, Shahed Iqbal, Camille Renard, Rebecca J Chan, Ken Hasegawa, Hao Hu, Preston Tse, Jiajun Yan, Michael J Zoratti, Feng Xie, Giridharan Ramsingh.

   BACKGROUND: TP53 mutations, which are present in 5% to 10% of patients with acute myeloid leukemia (AML), are associated with treatment resistance and poor outcomes. First-line therapies for TP53-mutated (TP53m) AML consist of intensive chemotherapy (IC), hypomethylating agents (HMA), or venetoclax combined with HMA (VEN + HMA).
METHODS: We conducted a systematic review and meta-analysis to describe and compare treatment outcomes in newly diagnosed treatment-naïve patients with TP53m AML. Randomized controlled trials, single-arm trials, prospective observational studies, and retrospective studies were included that reported on complete remission (CR), CR with incomplete hematologic recovery (CRi), overall survival (OS), event-free survival (EFS), duration of response (DoR), and overall response rate (ORR) among patients with TP53m AML receiving first-line treatment with IC, HMA, or VEN + HMA.
RESULTS: Searches of EMBASE and MEDLINE identified 3006 abstracts, and 17 publications describing 12 studies met the inclusion criteria. Random-effects models were used to pool response rates, and time-related outcomes were analyzed with the median of medians method. IC was associated with the greatest CR rate of 43%, and CR rates were 33% for VEN + HMA and 13% for HMA. Rates of CR/CRi were comparable for IC (46%) and VEN + HMA (49%) but were lower for HMA (13%). Median OS was uniformly poor across treatments: IC, 6.5 months; VEN + HMA, 6.2 months; and HMA, 6.1 months. For IC, the EFS estimate was 3.7 months; EFS was not reported for VEN + HMA or HMA. The ORR was 41% for IC, 65% for VEN + HMA, and 47% for HMA. DoR was 3.5 months for IC, 5.0 months for VEN + HMA, and was not reported for HMA.
CONCLUSIONS: Despite improved responses seen with IC and VEN + HMA compared to HMA, survival was uniformly poor, and clinical benefits were limited across all treatments for patients with newly diagnosed, treatment-naïve TP53m AML, demonstrating a significant need for improved treatment for this difficult-to-treat population.

Keywords:  Acute myeloid leukemia; Hypomethylating agents; Intensive chemotherapy; TP53 mutations; Venetoclax

DOI:  https://doi.org/10.1186/s13045-023-01417-5
Hemasphere. 2023 Apr;7(4): e851

Primary Cancer Matters in Therapy-related Myeloid Neoplasm Patients Receiving Allogeneic Hematopoietic Cell Transplantation: A Study From the Chronic Malignancies Working Party of the EBMT.

Marie Robin, Liesbeth C de Wreede, Thomas Schroeder, Friedrich Stölzel, Nicolaus Kröger, Linda Koster, Uwe Platzbecker, Jürgen Finke, Arnold Ganser, Didier Blaise, Fabio Ciceri, Johan Maertens, Hélène Labussière Wallet, Junfeng Wang, Patrice Chevallier, Jakob Passweg, Jan J Cornelissen, Stéphanie Nguyen, Edouard Forcade, Amandine Charbonnier, Francesca Bonifazi, Patrick Hayden, Donal P McLornan, Ibrahim Yakoub-Agha.

DOI: https://doi.org/10.1097/HS9.0000000000000851
Leuk Lymphoma. 2023 Mar 08. 1-7

Poor post-induction outcomes in patients with acute myeloid leukemia previously treated with hypomethylating agents.

Michelle Y Zhang, Megan Othus, Carole Shaw, Kelda G Schonhoff, Anna B Halpern, Jacob Appelbaum, Paul C Hendrie, Roland B Walter, Elihu H Estey, Mary-Elizabeth M Percival.

  Patients with acute myeloid leukemia (AML) who have failed hypomethylating agents (HMA) have a poor prognosis. We examined whether high intensity induction chemotherapy could abrogate negative outcomes in 270 patients with AML or other high-grade myeloid neoplasms. Prior HMA therapy was significantly associated with a lower overall survival (OS) as compared to a reference group of patients with secondary disease without prior HMA therapy (median 7.2 vs 13.1 months). In patients with prior HMA therapy, high intensity induction was associated with a non-significant trend toward longer OS (median 8.2 vs 4.8 months) and decreased rates of treatment failure (39% vs 64%). These results redemonstrate poor outcomes in patients with prior HMA and suggest possible benefit of high intensity induction that should be evaluated in future studies.

Keywords:  Hypomethylating agent; acute myeloid leukemia; high intensity induction; outcomes

DOI:  https://doi.org/10.1080/10428194.2023.2186732
Am J Hematol. 2023 Mar 07.

Spectrum of renal pathological findings in patients with chronic myelomonocytic leukemia and kidney injury.

Nate Gipe, Nelson Leung, Terra Lasho, Abhishek Mangaonkar, Hassan Alkhateeb, Aref Al-Kali, Naseema Gangat, William Hogan, Kristen McCullough, Ayalew Tefferi, Mariam Priya Alexander, Mrinal M Patnaik.

DOI: https://doi.org/10.1002/ajh.26902
Cell Death Differ. 2023 Mar 09.

Targeting HDAC3 to overcome the resistance to ATRA or arsenic in acute promyelocytic leukemia through ubiquitination and degradation of PML-RARα.

Bo Dai, Feng Wang, Ying Wang, Jiayan Zhu, Yunxuan Li, Tingting Zhang, Luyao Zhao, Lining Wang, Wenhui Gao, Junmin Li, Honghu Zhu, Ke Li, Jiong Hu.

Acute promyelocytic leukemia (APL) is driven by the oncoprotein PML-RARα, which recruits corepressor complexes, including histone deacetylases (HDACs), to suppress cell differentiation and promote APL initiation. All-trans retinoic acid (ATRA) combined with arsenic trioxide (ATO) or chemotherapy highly improves the prognosis of APL patients. However, refractoriness to ATRA and ATO may occur, which leads to relapsed disease in a group of patients. Here, we report that HDAC3 was highly expressed in the APL subtype of AML, and the protein level of HDAC3 was positively associated with PML-RARα. Mechanistically, we found that HDAC3 deacetylated PML-RARα at lysine 394, which reduced PIAS1-mediated PML-RARα SUMOylation and subsequent RNF4-induced ubiquitylation. HDAC3 inhibition promoted PML-RARα ubiquitylation and degradation and reduced the expression of PML-RARα in both wild-type and ATRA- or ATO-resistant APL cells. Furthermore, genetic or pharmacological inhibition of HDAC3 induced differentiation, apoptosis, and decreased cellular self-renewal of APL cells, including primary leukemia cells from patients with resistant APL. Using both cell line- and patient-derived xenograft models, we demonstrated that treatment with an HDAC3 inhibitor or combination of ATRA/ATO reduced APL progression. In conclusion, our study identifies the role of HDAC3 as a positive regulator of the PML-RARα oncoprotein by deacetylating PML-RARα and suggests that targeting HDAC3 could be a promising strategy to treat relapsed/refractory APL.

DOI: https://doi.org/10.1038/s41418-023-01139-8
BMC Cancer. 2023 Mar 10. 23(1): 231

Patient-guided dose reduction of tyrosine kinase inhibitors in chronic myeloid leukaemia (RODEO study): study protocol for a prospective, multicentre, single-arm trial.

Melissa F Djodikromo, Rosella Pmg Hermens, Bart Jf van den Bemt, Yolba Smit, Tim M Govers, Charlotte L Bekker, Nicole Ma Blijlevens.

   BACKGROUND: Dose reduction of tyrosine kinase inhibitors (TKI) in patients with chronic myeloid leukaemia (CML) with an optimal response to TKIs may support cost-effective medication use by maintaining therapeutic effectiveness while reducing adverse events and medication costs. As the choice for dose reduction depends on patients' individual needs and preferences, a patient-centred approach is warranted. Therefore, a study to evaluate the effectiveness of patient-guided dose reduction in patients with CML who are in a major or deep molecular response is designed.
METHODS: This study is a prospective, multicentre, single-arm study. 147 patients with CML (aged ≥ 18 years) in chronic phase, who are treated with imatinib, bosutinib, dasatinib, nilotinib or ponatinib, and have reached at least major molecular response (defined as having BCR-ABL levels < 0.1% for an uninterrupted period of 6 months) are eligible. Patients will use an online patient decision aid and a shared decision making consultation will be held, after which patients who choose to will receive a personalised, lower TKI dose. Primary outcome is the proportion of patients with intervention failure at 12 months after dose reduction, defined as patients who have restarted their initial dose due to (expected) loss of major molecular response. For this, BCR-ABL1 levels will be analysed from blood samples drawn at baseline, 6 weeks after dose reduction and 3-monthly thereafter. Secondary outcomes include the proportion of patients with intervention failure at 6 and 18 months after dose reduction. Other outcomes include differences before and after dose reduction regarding the number and severity of patient-reported side effects; quality of life; beliefs about medicines; and medication adherence. Patients' level of decisional conflict and regret after choosing dose reduction will be assessed, as will the decisional process experienced by patients and healthcare providers.
DISCUSSION: Outcomes of this trial using a personalised approach will provide clinical and patient-reported data to guide future dose reduction of TKIs in CML. If the strategy appears to be effective, it may be implemented as another valid option to offer next to standard of care to prevent potential unnecessary exposure to higher TKI doses in this selected group of patients.
TRIAL REGISTRATION: EudraCT number 2021-006581-20.

Keywords:  Chronic myeloid leukaemia; Dose reduction; Patient-centred care; Shared decision making; Tyrosine kinase inhibitors

DOI:  https://doi.org/10.1186/s12885-023-10697-6
World J Oncol. 2023 Feb;14(1): 40-50

Real-World Experience of Adults With Acute Myeloid Leukemia on Hypomethylating Agents With or Without Venetoclax at a Comprehensive Cancer Center.

Tracelyn Freeman, Kiersten Williams, Marcin Puto, Allyson Waller, Eric M McLaughlin, James S Blachly, Julianna Roddy.

   Background: Venetoclax (VEN) in combination with hypomethylating agent (HMA) therapy is a standard treatment option for patients with newly diagnosed acute myeloid leukemia (AML); however, data are limited in the relapsed or refractory (R/R) populations and in those with poor-risk disease. A retrospective review was conducted involving patients with AML who received HMA alone or in combination with VEN (VEN + HMA).
Methods: VEN + HMA was compared to HMA alone in first-line and R/R settings. Patients were stratified by specific HMA and line of therapy. The primary endpoint was overall response rate (ORR) up to 6 months from start of treatment.
Results: Fifty-two patients were evaluated for efficacy and 78 patients for safety. ORR was 67% (VEN + HMA) versus 80% (HMA) in the first line and 50% versus 22% in R/R setting. A greater clinical benefit was seen with VEN + HMA compared to HMA in both lines of therapy (first-line: 87% vs. 80%; R/R: 75% vs. 67%). The median duration of response was longer with VEN + HMA first-line, but shorter in the R/R setting compared to HMA (8.3 vs. 7.2 months and 2.5 vs. 3.7 months, respectively). Of the 32 patients who responded to therapy, 63% had a complex karyotype. Survival benefits were greater with VEN + HMA in both lines of therapy, although not statistically significant. Grade 3/4 neutropenia was reported in all patients receiving VEN, and 95% of these patients also experienced grade 3/4 thrombocytopenia. There were three cases of tumor lysis syndrome.
Conclusion: The addition of VEN to HMA has consistently shown benefit as first-line treatment and may have some benefit in R/R settings as well. Further studies are needed to compare across various lines of treatment and unfavorable disease. Dynamic strategies that improve toxicity management should be considered.

Keywords:  Acute myeloid leukemia; Hypomethylating agents; Less intensive; Relapsed; Unfavorable; Venetoclax

DOI:  https://doi.org/10.14740/wjon1557
Blood. 2023 Mar 10. pii: blood.2022019160. [Epub ahead of print]

Prospective Validation of the Prognostic Relevance of CD34+CD38- AML Stem Cell frequency in the HOVON-SAKK132 trial.

Lok Lam Ngai, Diana Hanekamp, Fleur Janssen, Jannemieke Carbaat-Ham, Maaike A M Hofland, Mona M H E Fayed, Angèle Kelder, Laura Oudshoorn-van Marsbergen, Willemijn J Scholten, Alexander N Snel, Costa Bachas, Jesse M Tettero, Dimitri A Breems, Thomas Fischer, Bjorn T Gjertsen, Laimonas Griskevicius, Gunnar Juliusson, Arjan A van de Loosdrecht, Johan A Maertens, Markus G Manz, Thomas Pabst, Jakob R Passweg, Kimmo Porkka, Peter J M Valk, Patrycja Gradowska, Bob Löwenberg, David C de Leeuw, Jeroen J W M Janssen, Gert J Ossenkoppele, Jacqueline Cloos.

DOI: https://doi.org/10.1182/blood.2022019160
Ann Hematol. 2023 Mar 07.

Feasibility, safety, and efficacy of early prophylactic donor lymphocyte infusion after T cell-depleted allogeneic stem cell transplantation in acute leukemia patients.

Boris van der Zouwen, E A S Koster, P A von dem Borne, L E M Oosten, M W I Roza-Scholten, T J F Snijders, D van Lammeren, P van Balen, W A F Marijt, H Veelken, J H F Falkenburg, L C de Wreede, C J M Halkes.

  Prophylactic donor lymphocyte infusion (DLI) starting at 6 months after T cell-depleted allogeneic stem cell transplantation (TCD-alloSCT) can introduce a graft-versus-leukemia (GvL) effects with low risk of severe graft-versus-host-disease (GvHD). We established a policy to apply low-dose early DLI at 3 months after alloSCT to prevent early relapse. This study analyzes this strategy retrospectively. Of 220 consecutive acute leukemia patients undergoing TCD-alloSCT, 83 were prospectively classified to have a high relapse risk and 43 were scheduled for early DLI. 95% of these patients received freshly harvested DLI within 2 weeks of the planned date. In patients transplanted with reduced intensity conditioning and an unrelated donor, we found an increased cumulative incidence of GvHD between 3 and 6 months after TCD-alloSCT for patients receiving DLI at 3 months compared to patients who did not receive this DLI (0.42 (95%Confidence Interval (95% CI): 0.14-0.70) vs 0). Treatment success was defined as being alive without relapse or need for systemic immunosuppressive GvHD treatment. The five-year treatment success in patients with acute lymphatic leukemia was comparable between high- and non-high-risk disease (0.55 (95% CI: 0.42-0.74) and 0.59 (95% CI: 0.42-0.84)). It remained lower in high-risk acute myeloid leukemia (AML) (0.29 (95% CI: 0.18-0.46)) than in non-high-risk AML (0.47 (95% CI: 0.42-0.84)) due to an increased relapse rate despite early DLI.

Keywords:  Allogeneic stem cell transplantation; Graft-versus-host-disease; Prophylactic donor lymphocyte infusion; Treatment success

DOI:  https://doi.org/10.1007/s00277-023-05145-1
Blood. 2023 Mar 06. pii: blood.2022019493. [Epub ahead of print]

The International Consensus Classification of Acute Leukemias of Ambiguous Lineage.

Olga K Weinberg, Daniel A Arber, Hartmut Döhner, Charles G Mullighan, Etan Orgel, Anna Porwit, Richard M Stone, Michael J Borowitz.

DOI: https://doi.org/10.1182/blood.2022019493
Nat Genet. 2023 Mar 09.

Immune selection determines tumor antigenicity and influences response to checkpoint inhibitors.

Luis Zapata, Giulio Caravagna, Marc J Williams, Eszter Lakatos, Khalid AbdulJabbar, Benjamin Werner, Diego Chowell, Chela James, Lucie Gourmet, Salvatore Milite, Ahmet Acar, Nadeem Riaz, Timothy A Chan, Trevor A Graham, Andrea Sottoriva.

In cancer, evolutionary forces select for clones that evade the immune system. Here we analyzed >10,000 primary tumors and 356 immune-checkpoint-treated metastases using immune dN/dS, the ratio of nonsynonymous to synonymous mutations in the immunopeptidome, to measure immune selection in cohorts and individuals. We classified tumors as immune edited when antigenic mutations were removed by negative selection and immune escaped when antigenicity was covered up by aberrant immune modulation. Only in immune-edited tumors was immune predation linked to CD8 T cell infiltration. Immune-escaped metastases experienced the best response to immunotherapy, whereas immune-edited patients did not benefit, suggesting a preexisting resistance mechanism. Similarly, in a longitudinal cohort, nivolumab treatment removes neoantigens exclusively in the immunopeptidome of nonimmune-edited patients, the group with the best overall survival response. Our work uses dN/dS to differentiate between immune-edited and immune-escaped tumors, measuring potential antigenicity and ultimately helping predict response to treatment.

DOI: https://doi.org/10.1038/s41588-023-01313-1
Proc Natl Acad Sci U S A. 2023 Mar 14. 120(11): e2300605120

Altered DNA repair pathway engagement by engineered CRISPR-Cas9 nucleases.

Vikash P Chauhan, Phillip A Sharp, Robert Langer.

  CRISPR-Cas9 introduces targeted DNA breaks that engage competing DNA repair pathways, producing a spectrum of imprecise insertion/deletion mutations (indels) and precise templated mutations (precise edits). The relative frequencies of these pathways are thought to primarily depend on genomic sequence and cell state contexts, limiting control over mutational outcomes. Here, we report that engineered Cas9 nucleases that create different DNA break structures engage competing repair pathways at dramatically altered frequencies. We accordingly designed a Cas9 variant (vCas9) that produces breaks which suppress otherwise dominant nonhomologous end-joining (NHEJ) repair. Instead, breaks created by vCas9 are predominantly repaired by pathways utilizing homologous sequences, specifically microhomology-mediated end-joining (MMEJ) and homology-directed repair (HDR). Consequently, vCas9 enables efficient precise editing through HDR or MMEJ while suppressing indels caused by NHEJ in dividing and nondividing cells. These findings establish a paradigm of targeted nucleases custom-designed for specific mutational applications.

Keywords:  CRISPR; DNA repair; genome editing; molecular engineering; precise editing

DOI:  https://doi.org/10.1073/pnas.2300605120
Nature. 2023 Mar 08.

Fumarate induces vesicular release of mtDNA to drive innate immunity.

Vincent Zecchini, Vincent Paupe, Irene Herranz-Montoya, Joëlle Janssen, Inge M N Wortel, Jordan L Morris, Ashley Ferguson, Suvagata Roy Chowdury, Marc Segarra-Mondejar, Ana S H Costa, Gonçalo C Pereira, Laura Tronci, Timothy Young, Efterpi Nikitopoulou, Ming Yang, Dóra Bihary, Federico Caicci, Shun Nagashima, Alyson Speed, Kalliopi Bokea, Zara Baig, Shamith Samarajiwa, Maxine Tran, Thomas Mitchell, Mark Johnson, Julien Prudent, Christian Frezza.

Mutations in fumarate hydratase (FH) cause hereditary leiomyomatosis and renal cell carcinoma1. Loss of FH in the kidney elicits several oncogenic signalling cascades through the accumulation of the oncometabolite fumarate2. However, although the long-term consequences of FH loss have been described, the acute response has not so far been investigated. Here we generated an inducible mouse model to study the chronology of FH loss in the kidney. We show that loss of FH leads to early alterations of mitochondrial morphology and the release of mitochondrial DNA (mtDNA) into the cytosol, where it triggers the activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING)-TANK-binding kinase 1 (TBK1) pathway and stimulates an inflammatory response that is also partially dependent on retinoic-acid-inducible gene I (RIG-I). Mechanistically, we show that this phenotype is mediated by fumarate and occurs selectively through mitochondrial-derived vesicles in a manner that depends on sorting nexin 9 (SNX9). These results reveal that increased levels of intracellular fumarate induce a remodelling of the mitochondrial network and the generation of mitochondrial-derived vesicles, which allows the release of mtDNAin the cytosol and subsequent activation of the innate immune response.

DOI: https://doi.org/10.1038/s41586-023-05770-w
Nature. 2023 Mar 08.

Macrophage fumarate hydratase restrains mtRNA-mediated interferon production.

Alexander Hooftman, Christian G Peace, Dylan G Ryan, Emily A Day, Ming Yang, Anne F McGettrick, Maureen Yin, Erica N Montano, Lihong Huo, Juliana E Toller-Kawahisa, Vincent Zecchini, Tristram A J Ryan, Alfonso Bolado-Carrancio, Alva M Casey, Hiran A Prag, Ana S H Costa, Gabriela De Los Santos, Mariko Ishimori, Daniel J Wallace, Swamy Venuturupalli, Efterpi Nikitopoulou, Norma Frizzell, Cecilia Johansson, Alexander Von Kriegsheim, Michael P Murphy, Caroline Jefferies, Christian Frezza, Luke A J O'Neill.

Metabolic rewiring underlies the effector functions of macrophages1-3, but the mechanisms involved remain incompletely defined. Here, using unbiased metabolomics and stable isotope-assisted tracing, we show that an inflammatory aspartate-argininosuccinate shunt is induced following lipopolysaccharide stimulation. The shunt, supported by increased argininosuccinate synthase (ASS1) expression, also leads to increased cytosolic fumarate levels and fumarate-mediated protein succination. Pharmacological inhibition and genetic ablation of the tricarboxylic acid cycle enzyme fumarate hydratase (FH) further increases intracellular fumarate levels. Mitochondrial respiration is also suppressed and mitochondrial membrane potential increased. RNA sequencing and proteomics analyses demonstrate that there are strong inflammatory effects resulting from FH inhibition. Notably, acute FH inhibition suppresses interleukin-10 expression, which leads to increased tumour necrosis factor secretion, an effect recapitulated by fumarate esters. Moreover, FH inhibition, but not fumarate esters, increases interferon-β production through mechanisms that are driven by mitochondrial RNA (mtRNA) release and activation of the RNA sensors TLR7, RIG-I and MDA5. This effect is recapitulated endogenously when FH is suppressed following prolonged lipopolysaccharide stimulation. Furthermore, cells from patients with systemic lupus erythematosus also exhibit FH suppression, which indicates a potential pathogenic role for this process in human disease. We therefore identify a protective role for FH in maintaining appropriate macrophage cytokine and interferon responses.

DOI: https://doi.org/10.1038/s41586-023-05720-6
Cancer Res. 2023 Mar 06. pii: CAN-22-3631. [Epub ahead of print]

Nucleophosmin plays a role in repairing DNA damage and is a target for cancer treatment.

Konjeti R Sekhar, Michael L Freeman.

Nucleophosmin (NPM1) is frequently mutated in acute myeloid leukemia, and NPM1 expression is elevated in several cancer types. NPM1 is a multifunctional oligomeric protein involved in numerous cellular functions that include participating in liquid-liquid phase separation, ribosome biogenesis, chaperoning of histones, and modulation of transcription. In this review, we discuss the underappreciated role of NPM1 in DNA damage repair, specifically Polη-mediated translesion synthesis, base excision, and homologous recombination and highlight the therapeutic potential of NPM1 targeting in cancer treatment.

DOI: https://doi.org/10.1158/0008-5472.CAN-22-3631
Blood. 2023 Mar 08. pii: blood.2022018711. [Epub ahead of print]

Plasma cell derived mtDAMPs activate macrophage STING pathway which promotes myeloma progression.

Aisha Jibril, Charlotte Hellmich, Edyta Wojtowicz, Katherine Hampton, Rebecca S Maynard, Ravindu De Silva, Dominic J Fowler-Shorten, Jayna J Mistry, Jamie A Moore, Kristian M Bowles, Stuart A Rushworth.

Mitochondrial damage-associated molecular patterns (mtDAMPs) include proteins, lipids, metabolites and DNA and have various context specific immunoregulatory functions. Cell-free mitochondrial DNA (mtDNA) is recognised via pattern recognition receptors and is a potent activator of the innate immune system. Cell-free mtDNA is elevated in the circulation of trauma and cancer patients, however the functional consequences of elevated mtDNA are largely undefined. Multiple myeloma (MM) relies upon cellular interactions within the bone marrow (BM) microenvironment for survival and progression. Here, using in-vivo models, we describe the role of MM cell derived mtDAMPs in the pro-tumoral BM microenvironment, and the mechanism and functional consequence of mtDAMPs in myeloma disease progression. Initially, we identified elevated levels of mtDNA in the peripheral blood serum of MM patients compared to healthy controls. Using the MM1S cells engrafted into NSG mice we established that elevated mtDNA was derived from MM cells. We further show that BM macrophages sense and respond to mtDAMPs through the STING pathway and inhibition of this pathway reduces MM tumor-burden in the KaLwRij-5TGM1 mouse model. Moreover, we found that MM derived mtDAMPs induced upregulation of chemokine signatures in BM macrophages and inhibition of this signature resulted in egress of MM cells from the BM. Here, we demonstrate that malignant plasma cells release mtDNA, a form of mtDAMPs, into the myeloma BM microenvironment, which in turn activates macrophages via STING signalling. We establish the functional role of these mtDAMP-activated macrophages in promoting disease progression and retaining MM cells in the pro-tumoral BM microenvironment.

DOI: https://doi.org/10.1182/blood.2022018711
Elife. 2023 Mar 06. pii: e81656. [Epub ahead of print]12

Identification of phenotypically, functionally, and anatomically distinct stromal niche populations in human bone marrow based on single-cell RNA sequencing.

Hongzhe Li, Sandro Bräunig, Parashar Dhapolar, Göran Karlsson, Stefan Lang, Stefan Scheding.

  Hematopoiesis is regulated by the bone marrow (BM) stroma. However, cellular identities and functions of the different BM stromal elements in humans remain poorly defined. Based on single-cell RNA sequencing (scRNAseq), we systematically characterized the human non-hematopoietic BM stromal compartment and we investigated stromal cell regulation principles based on the RNA velocity analysis using scVelo and studied the interactions between the human BM stromal cells and hematopoietic cells based on ligand-receptor (LR) expression using CellPhoneDB. scRNAseq led to the identification of six transcriptionally and functionally distinct stromal cell populations. Stromal cell differentiation hierarchy was recapitulated based on RNA velocity analysis and in vitro proliferation capacities and differentiation potentials. Potential key factors that might govern the transition from stem and progenitor cells to fate-committed cells were identified. In situ localization analysis demonstrated that different stromal cells were localized in different niches in the bone marrow. In silico cell-cell communication analysis further predicted that different stromal cell types might regulate hematopoiesis through distinct mechanisms. These findings provide the basis for a comprehensive understanding of the cellular complexity of the human BM microenvironment and the intricate stroma-hematopoiesis crosstalk mechanisms, thus refining our current view on human hematopoietic niche organization.

Keywords:  human; regenerative medicine; stem cells

DOI:  https://doi.org/10.7554/eLife.81656