bims-tremyl 2023-03-26 papers

bims-tremyl

Biomed News

on Therapy resistance biology in myeloid leukemia

Issue of 2023–03–26
37 papers selected by
Paolo Gallipoli, Barts Cancer Institute, Queen Mary University of London

Characteristics and clinical outcomes of patients with acute myeloid leukemia with inv(3)(q21q26.2) or t(3;3)(q21;q26.2).
Current landscape of translational and clinical research in myelodysplastic syndromes/neoplasms (MDS): Proceedings from the 1st International Workshop on MDS (iwMDS) Of the International Consortium for MDS (icMDS).
Impact of measurable residual disease on outcomes of unrelated donor haematopoietic cell transplantation with post-transplant cyclophosphamide in AML in first complete remission.
Survival outcomes with oral azacitidine maintenance in patients with acute myeloid leukemia in remission by receipt of initial chemotherapy: subgroup analyses from the phase 3 QUAZAR AML-001 trial.
Asciminib monotherapy in patients with CML-CP without BCR::ABL1 T315I mutations treated with at least two prior TKIs: 4-year phase 1 safety and efficacy results.
m6A-driven SF3B1 translation control steers splicing to direct genome integrity and leukemogenesis.
Clinicopathologic Features of IDH2 R172-Mutated Myeloid Neoplasms.
Impact of TP53 on outcome of patients with myelofibrosis undergoing hematopoietic stem cell transplantation.
Myeloid sarcoma with NPM1 mutation may be clinically and genetically distinct from AML with NPM1 mutation: a study from the Bone Marrow Pathology Group.
RNA splicing factor Rbm25 underlies heterogeneous preleukemic clonal expansion in mice.
Structural Variation Cooperates with Permissive Chromatin to Control Enhancer Hijacking-Mediated Oncogenic Transcription.
ALWAYS STRESSED BUT NEVER EXHAUSTED: HOW STEM CELLS IN MYELOID NEOPLASMS AVOID EXTINCTION IN INFLAMMATORY CONDITIONS.
Identifying prognostic gene panels in acute myeloid leukemia.
Utility of Targeted Gene Sequencing to Differentiate Myeloid Malignancies from other Cytopenic Conditions.
The Clinical Picture of the ERCC6L2 Disease - from Bone Marrow Failure to Acute Leukemia.
Redox metabolism maintains the leukemogenic capacity and drug resistance of AML cells.
Temporal multimodal single-cell profiling of native hematopoiesis illuminates altered differentiation trajectories with age.
Cryo-EM analyses of KIT and oncogenic mutants reveal structural oncogenic plasticity and a target for therapeutic intervention.
Type I interferon signaling in malignant blasts contributes to treatment efficacy in AML patients.
Prediction model for drug response of acute myeloid leukemia patients.
Lycorine induces apoptosis of acute myeloid leukemia cells and inhibits triglyceride production via binding and targeting FABP5.
Hematopoietic stem cells preferentially traffic misfolded proteins to aggresomes and depend on aggrephagy to maintain protein homeostasis.
Molecular targeting of the UDP-glucuronosyltransferase enzymes in high-eukaryotic translation initiation factor 4E refractory/relapsed acute myeloid leukemia patients: a randomized phase II trial of vismodegib, ribavirin with or without decitabine.
Prognostic relevance of NPM1, CEBPA, and FLT3 mutations in cytogenetically normal adult AML patients.
TP53-mediated clonal hematopoiesis confers increased risk for incident atherosclerotic disease.
Clinical characteristics and outcomes of children with newly diagnosed acute myeloid leukemia and hyperleukocytosis managed with different cytoreductive methods.
A miRNA signature related to stemness identifies high-risk patients in paediatric acute myeloid leukaemia.
Novel Scheme for Defining the Clinical Implications of TP53 Mutations in Myeloid Neoplasia.
Does leukocytosis remain a predictive factor for survival outcomes in patients with acute promyelocytic leukemia receiving ATRA plus a chemotherapy-based regimen? A prospective multicenter analysis from TALWG.
Clonal hematopoiesis of indeterminate potential and clonal cytopenias of undetermined significance: 2023 update on clinical associations and management recommendations.
An evaluation of fedratinib for adult patients with newly diagnosed and previously treated myelofibrosis.
Sequencing Identifies Relapse-Prone AML Patients.
10-year nationwide trends in incidence, treatment patterns, and mortality of patients with myelodysplastic syndromes in Denmark.
Improved Access to HCT with Reduced Racial Disparities Through Integration with Leukemia Care and Haploidentical Donors.
pH regulates hematopoietic stem cell potential via polyamines.
Multicenter retrospective analysis of clinical outcome of adult patients with mixed-phenotype acute leukemia treated with acute myeloid leukemia-like or acute lymphoblastic leukemia-like chemotherapy and impact of allogeneic stem cell transplantation: a Campus ALL study.
Context is key for FLT3-ITD.

Haematologica. 2023 Mar 23.

Characteristics and clinical outcomes of patients with acute myeloid leukemia with inv(3)(q21q26.2) or t(3;3)(q21;q26.2).

Guillaume Richard-Carpentier, Caitlin R Rausch, Koji Sasaki, Danielle Hammond, Kiyomi Morita, Koichi Takahashi, Guilin Tang, Rashmi Kanagal-Shamanna, Kapil Bhalla, Courtney D Dinardo, Gautam Borthakur, Naveen Pemmaraju, Elizabeth J Shpall, Amin Alousi, Naval G Daver, Guillermo Garcia-Manero, Marina Y Konopleva, Farhad Ravandi, Hagop M Kantarjian, Tapan M Kadia.

Acute myeloid leukemia (AML) with inv(3)(q21q26.2)/t(3;3)(q21;q26.2) has a very poor prognosis. Determinants of clinical outcomes and optimal treatment remain uncertain. We retrospectively reviewed 108 cases of AML with inv(3)/t(3;3) and evaluated clinicopathological characteristics and clinical outcomes: 53 newly diagnosed (ND) AML and 55 relapsed/refractory (R/R) AML. Median age was 55 years. White blood cell (WBC) count ≥ 20 x 109/L and platelet count ≥ 140 x 109/L was observed in 25% and 32% of ND patients, respectively. Anomalies involving chromosome 7 were identified in 56% of patients. The most frequently mutated genes were SF3B1, PTPN11, NRAS, KRAS and ASXL1. In ND patients, the composite complete remission (CRc) rate was 46% overall; 46% with high-intensity treatments and 47% with low-intensity treatments. The 30-day mortality was 14% and 0%, with high- and low-intensity treatment, respectively. In R/R patients, the CRc rate was 14%. Venetoclax based-regimens were associated with a CRc rate of 33%. The 3-year overall survival (OS) was 8.8% and 7.1% in ND and R/R patients, respectively. The 3-year cumulative incidence of relapse was 81.7% overall. Older age, high WBC, high peripheral blast count, secondary AML and KRAS, ASXL1, DNMT3A mutations were associated with worse OS in univariable analyses. The 5-year OS rates were 44% and 6% with or without HSCT in CR1, respectively. AML with inv(3)/t(3;3) is associated with low CR rates, very high risk of relapse and dismal long-term survival. Intensive chemotherapy and HMA provide similar rates of remission and patients achieving CR benefit from HSCT in CR1.

DOI: https://doi.org/10.3324/haematol.2022.282030
Blood Rev. 2023 Mar 11. pii: S0268-960X(23)00033-4. [Epub ahead of print] 101072

Current landscape of translational and clinical research in myelodysplastic syndromes/neoplasms (MDS): Proceedings from the 1st International Workshop on MDS (iwMDS) Of the International Consortium for MDS (icMDS).

Jan Philipp Bewersdorf, Zhuoer Xie, Rafael Bejar, Uma Borate, Jacqueline Boultwood, Andrew M Brunner, Rena Buckstein, Hetty E Carraway, Jane E Churpek, Naval G Daver, Matteo Giovanni Della Porta, Amy E DeZern, Pierre Fenaux, Maria E Figueroa, Steven D Gore, Elizabeth A Griffiths, Stephanie Halene, Robert P Hasserjian, Christopher S Hourigan, Tae Kon Kim, Rami Komrokji, Vijay K Kuchroo, Alan F List, Sanam Loghavi, Ravindra Majeti, Olatoyosi Odenike, Mrinal M Patnaik, Uwe Platzbecker, Gail J Roboz, David A Sallman, Valeria Santini, Guillermo Sanz, Mikkael A Sekeres, Maximilian Stahl, Daniel T Starczynowski, David P Steensma, Justin Taylor, Omar Abdel-Wahab, Mina L Xu, Michael R Savona, Andrew H Wei, Amer M Zeidan.

  Biological events that contribute to the pathogenesis of myelodysplastic syndromes/neoplasms (MDS) are becoming increasingly characterized and are being translated into rationally designed therapeutic strategies. Herein, we provide updates from the first International Workshop on MDS (iwMDS) of the International Consortium for MDS (icMDS) detailing recent advances in understanding the genetic landscape of MDS, including germline predisposition, epigenetic and immune dysregulation, the complexities of clonal hematopoiesis progression to MDS, as well as novel animal models of the disease. Connected to this progress is the development of novel therapies targeting specific molecular alterations, the innate immune system, and immune checkpoint inhibitors. While some of these agents have entered clinical trials (e.g., splicing modulators, IRAK1/4 inhibitors, anti-CD47 and anti-TIM3 antibodies, and cellular therapies), none have been approved for MDS. Additional preclinical and clinical work is needed to develop a truly individualized approach to the care of MDS patients.

Keywords:  Animal models; Genetics; Immunology; MDS; Myelodysplastic syndrome; Novel therapies

DOI:  https://doi.org/10.1016/j.blre.2023.101072
Br J Haematol. 2023 Mar 22.

Impact of measurable residual disease on outcomes of unrelated donor haematopoietic cell transplantation with post-transplant cyclophosphamide in AML in first complete remission.

Arnon Nagler, Myriam Labopin, Bhagirathbhai Dholaria, Didier Blaise, Sergey Bondarenko, Jan Vydra, Goda Choi, Montserrat Rovira, Péter Reményi, Ellen Meijer, Claude Eric Bulabois, J L Diez-Martin, Ibrahim Yakoub-Agha, Eolia Brissot, Alexandros Spyridonidis, Jaime Sanz, Amit Patel, Mutlu Arat, Ali Bazarbachi, Gesine Bug, Bipin N Savani, Sebastian Giebel, Fabio Ciceri, Mohamad Mohty.

  Pre-transplant measurable residual disease (MRD) predicts relapse and outcome of allogeneic haematopoietic cell transplantation (allo-HCT). The impact of MRD on the outcomes of post-transplant cyclophosphamide (PTCy)-based allo-HCT from a matched unrelated donor (UD) is unknown. This study assessed the impact of MRD in acute myeloid leukaemia (AML) in the first complete remission (CR1). A total of 272 patients (MRD negative [MRD-], n = 165; MRD positive [MRD+], n = 107) with a median follow-up of 19 (range: 16-24) months were studied. The incidence of grades II-IV and grades III-IV acute GVHD at day 180 was 25.2% and 25% (p = 0.99), and 10.6% and 6.8% (p = 0.29), respectively, and 2-year chronic GVHD was 35% and 30.4% (p = 0.96) in MRD+ and MRD- cohorts, respectively. In multivariate analysis, MRD+ status was associated with a higher incidence of relapse (RI) (hazard ratio [HR] = 2.56, 95% CI: 1.39-4.72), lower leukaemia-free survival (LFS) (HR = 2.04, 95% CI: 1.23-3.39), overall survival (OS) (HR = 1.83, 95% CI: 1.04-3.25) and GVHD-free, relapse-free survival (GRFS) (HR = 1.69, 95% CI: 1.10-2.58). MRD status did not have a significant impact on non-relapse mortality (NRM), or acute or chronic GVHD risk. Among patients with AML undergoing UD allo-HCT with PTCy, pre-transplant MRD+ status predicted a higher relapse rate, lower LFS, OS and GRFS.

Keywords:  acute myeloid leukaemia; allogeneic haematopoietic cell transplantation; measurable residual disease; post-transplant cyclophosphamide; unrelated donor

DOI:  https://doi.org/10.1111/bjh.18765
Haematologica. 2023 Mar 23.

Survival outcomes with oral azacitidine maintenance in patients with acute myeloid leukemia in remission by receipt of initial chemotherapy: subgroup analyses from the phase 3 QUAZAR AML-001 trial.

Andrew H Wei, Gail J Roboz, Herve Dombret, Hartmut Dohner, Andre C Schuh, Pau Montesinos, Dominik Selleslag, Sergey N Bondarenko, Thomas Prebet, Yinzhi Lai, Barry Skikne, C L Beach, Farhad Ravandi.

Not available.

DOI: https://doi.org/10.3324/haematol.2022.282296
Leukemia. 2023 Mar 22.

Asciminib monotherapy in patients with CML-CP without BCR::ABL1 T315I mutations treated with at least two prior TKIs: 4-year phase 1 safety and efficacy results.

Michael J Mauro, Timothy P Hughes, Dong-Wook Kim, Delphine Rea, Jorge E Cortes, Andreas Hochhaus, Koji Sasaki, Massimo Breccia, Moshe Talpaz, Oliver Ottmann, Hironobu Minami, Yeow Tee Goh, Daniel J DeAngelo, Michael C Heinrich, Valle Gómez-García de Soria, Philipp le Coutre, Francois-Xavier Mahon, Jeroen J W M Janssen, Michael Deininger, Naranie Shanmuganathan, Mark B Geyer, Silvia Cacciatore, Fotis Polydoros, Nithya Agrawal, Matthias Hoch, Fabian Lang.

Asciminib is approved for patients with Philadelphia chromosome-positive chronic-phase chronic myeloid leukemia (CML-CP) who received ≥2 prior tyrosine kinase inhibitors or have the T315I mutation. We report updated results of a phase 1, open-label, nonrandomized trial (NCT02081378) assessing the safety, tolerability, and antileukemic activity of asciminib monotherapy 10-200 mg once or twice daily in 115 patients with CML-CP without T315I (data cutoff: January 6, 2021). After ≈4-year median exposure, 69.6% of patients remained on asciminib. The most common grade ≥3 adverse events (AEs) included increased pancreatic enzymes (22.6%), thrombocytopenia (13.9%), hypertension (13.0%), and neutropenia (12.2%); all-grade AEs (mostly grade 1/2) included musculoskeletal pain (59.1%), upper respiratory tract infection (41.7%), and fatigue (40.9%). Clinical pancreatitis and arterial occlusive events (AOEs) occurred in 7.0% and 8.7%, respectively. Most AEs occurred during year 1; the subsequent likelihood of new events, including AOEs, was low. By data cutoff, among patients without the indicated response at baseline, 61.3% achieved BCR::ABL1 ≤ 1%, 61.6% achieved ≤0.1% (major molecular response [MMR]), and 33.7% achieved ≤0.01% on the International Scale. MMR was maintained in 48/53 patients who achieved it and 19/20 who were in MMR at screening, supporting the long-term safety and efficacy of asciminib in this population.

DOI: https://doi.org/10.1038/s41375-023-01860-w
Mol Cell. 2023 Mar 08. pii: S1097-2765(23)00151-X. [Epub ahead of print]

m6A-driven SF3B1 translation control steers splicing to direct genome integrity and leukemogenesis.

Maciej Cieśla, Phuong Cao Thi Ngoc, Sowndarya Muthukumar, Gabriele Todisco, Magdalena Madej, Helena Fritz, Marios Dimitriou, Danny Incarnato, Eva Hellström-Lindberg, Cristian Bellodi.

  SF3B1 is the most mutated splicing factor (SF) in myelodysplastic syndromes (MDSs), which are clonal hematopoietic disorders with variable risk of leukemic transformation. Although tumorigenic SF3B1 mutations have been extensively characterized, the role of "non-mutated" wild-type SF3B1 in cancer remains largely unresolved. Here, we identify a conserved epitranscriptomic program that steers SF3B1 levels to counteract leukemogenesis. Our analysis of human and murine pre-leukemic MDS cells reveals dynamic regulation of SF3B1 protein abundance, which affects MDS-to-leukemia progression in vivo. Mechanistically, ALKBH5-driven 5' UTR m6A demethylation fine-tunes SF3B1 translation directing splicing of central DNA repair and epigenetic regulators during transformation. This impacts genome stability and leukemia progression in vivo, supporting an integrative analysis in humans that SF3B1 molecular signatures may predict mutational variability and poor prognosis. These findings highlight a post-transcriptional gene expression nexus that unveils unanticipated SF3B1-dependent cancer vulnerabilities.

Keywords:  ALKBH5; MYC; SF3B1; acute myeloid leukemia; alternative splicing; genome integrity; m(6)A; myelodysplastic syndromes; p53; translation

DOI:  https://doi.org/10.1016/j.molcel.2023.02.024
Am J Clin Pathol. 2023 Mar 22. pii: aqad019. [Epub ahead of print]

Clinicopathologic Features of IDH2 R172-Mutated Myeloid Neoplasms.

Adam R Davis, Briana C Canady, Nidhi Aggarwal, Nathanael G Bailey.

   OBJECTIVES: IDH1 and IDH2 are among the most commonly mutated genes in myeloid neoplasms (MNs). It has been proposed that IDH2 R172 mutations (mR172) define a molecular subtype of acute myeloid leukemia (AML), but the clinicopathologic features of AML with mR172 have not been fully described.
METHODS: We retrospectively identified and characterized all mR172 MNs with increased blasts in our archive for comparison to a similar number of MNs with IDH2 R140 (mR140) and IDH1 R132 (mR132) mutations (n = 39).
RESULTS: mR172 cases had lower leukocyte counts and bone marrow cellularity than did non-mR172 cases. mR172 MNs often displayed blasts with highly invaginated, cleaved nuclei and typically expressed CD34, HLA-DR, CD117, and CD13 but often with diminished CD33. mR172 cases often had co-occurring mutations in myelodysplasia-associated genes and/or an adverse karyotype. Despite frequent adverse-risk genetic changes, in our cohort mR172 cases had significantly improved overall survival vs non-mR172 cases (P = .01), and we validated that mR172 was associated with improved survival in an independent large data set.
CONCLUSIONS: We show that MNs with mR172 represent a morphologically and phenotypically distinct subtype, which in our cohort exhibited relatively favorable survival that is not captured in current AML risk assignment.

Keywords:  Acute myeloid leukemia; Isocitrate dehydrogenase; Myeloid neoplasia

DOI:  https://doi.org/10.1093/ajcp/aqad019
Blood. 2023 Mar 20. pii: blood.2023019630. [Epub ahead of print]

Impact of TP53 on outcome of patients with myelofibrosis undergoing hematopoietic stem cell transplantation.

Nico Gagelmann, Anita Badbaran, Rachel B Salit, Thomas Schroeder, Carmelo Gurnari, Simona Pagliuca, Victoria Panagiota, Christina Rautenberg, Bruno Cassinat, Felicitas R Thol, Christine Wolschke, Marie Robin, Michael Heuser, Marie-Thérèse Rubio, Jaroslaw P Maciejewski, Hans Christian Reinhardt, Bart L Scott, Nicolaus Kröger.

TP53 mutations (TP53MT) have been associated with poor outcomes in various hematologic malignancies, but no data exist on its role in patients with myelofibrosis undergoing hematopoietic stem cell transplantation (HSCT). Here, we took advantage of a large international multicenter cohort to evaluate the role of TP53MTin this setting. Among 349 included patients, 49 (13%) had detectable TP53MT, of whom 30 showed a multi-hit configuration. Median variant allele frequency was 20.3%. Cytogenetic risk was favorable (71%), unfavorable (23%), and very high (6%), with complex karyotype present in 36 patients (10%). Median survival of TP53MT patients was 1.5 years vs 13.5 years for the TP53WT group (P<0.001). Outcome was driven by multi-hit TP53MT constellation (P<0.001), showing 6-year survival of 56% for single-hit vs 25% for multi-hit TP53MT carriers vs 64% for TP53WT. Outcome was independent of current transplant-specific risk factors and conditioning intensity. Similarly, cumulative incidence of relapse was 17% for single-hit vs 52% for multi-hit vs 21% for TP53WT. Ten patients with TP53MT (20%) presented as leukemic transformation vs only 7 (2%) in the TP53WT group (P<0.001). Out of the 10 patients with TP53MT, 8 showed multi-hit constellation. Median time to leukemic transformation was shorter for multi-and single-hit TP53MT (0.7 and 0.5 years, respectively) vs 2.5 years for TP53WT. In summary, multi-hit TP53MT represents a very high-risk group in myelofibrosis patients undergoing HSCT, whereas single-hit TP53MTalone showed similar outcome to non-mutated patients, informing prognostication for survival and relapse together with current transplant-specific tools.

DOI: https://doi.org/10.1182/blood.2023019630
Leuk Lymphoma. 2023 Mar 24. 1-9

Myeloid sarcoma with NPM1 mutation may be clinically and genetically distinct from AML with NPM1 mutation: a study from the Bone Marrow Pathology Group.

Bone Marrow Pathology Group

  Myeloid sarcoma (MS) is currently considered equivalent to de novo acute myeloid leukemia (AML); however, the relationship between these entities is poorly understood. This retrospective multi-institutional cohort study compared 43 MS with NPM1 mutation to 106 AML with NPM1 mutation. Compared to AML, MS had more frequent cytogenetic abnormalities including complex karyotype (p = .009 and p = .007, respectively) and was enriched in mutations of genes involved in histone modification, including ASXL1 (p = .007 and p = .008, respectively). AML harbored a higher average number of gene mutations (p = .002) including more frequent PTPN11 mutations (p < .001) and mutations of DNA-methylating genes including DNMT3A and IDH1 (both p < .001). MS had significantly shorter overall survival (OS) than AML (median OS: 44.9 vs. 93.2 months, respectively, p = .037). MS with NPM1 mutation has a unique genetic landscape, and poorer OS, compared to AML with NPM1 mutation.

Keywords:  Hematopoiesis; genetic and other predisposing conditions; leukemic progenitor cells; myeloid leukemias and dysplasias; neoplasia

DOI:  https://doi.org/10.1080/10428194.2023.2185091
Blood. 2023 Mar 22. pii: blood.2023019620. [Epub ahead of print]

RNA splicing factor Rbm25 underlies heterogeneous preleukemic clonal expansion in mice.

Charles Bramlett, Jiya Eerdeng, Du Jiang, Yeachan Lee, Ivon Garcia, Mary C Vergel-Rodriguez, Patrick Condie, Anna Nogalska, Rong Lu.

Clonal expansion sets the stage for cancer genesis by allowing for the accumulation of molecular alterations. While genetic mutations that induce clonal expansion and malignancy, such as Tet2, have been identified, these mutations are also frequently found in healthy individuals. Here, we tracked preleukemic clonal expansion using genetic barcoding in an inducible Tet2 knockout mouse model and found that only a small fraction of hematopoietic stem cells (HSCs) expanded excessively upon Tet2 knockout. These overexpanded HSCs expressed significantly lower levels of genes associated with leukemia and RNA splicing compared to non-overexpanded Tet2 knockout HSCs. Knocking down Rbm25, an identified RNA splicing factor, accelerated the expansion of Tet2-knockout hematopoietic cells in vitro and in vivo. Our data suggest that mutations of an epigenetic factor Tet2 induces variability in the expression of an RNA splicing factor Rbm25, which subsequently drives heterogeneous preleukemic clonal expansion. This heterogeneous clonal expansion could contribute to the variable disease risks across individuals.

DOI: https://doi.org/10.1182/blood.2023019620
Blood. 2023 Mar 22. pii: blood.2022017555. [Epub ahead of print]

Structural Variation Cooperates with Permissive Chromatin to Control Enhancer Hijacking-Mediated Oncogenic Transcription.

Giovanni Botten, Yuannyu Zhang, Kseniia Dudnyk, Yoon Jung Kim, Xin Liu, Jacob T Sanders, Aygun Imanci, Nathalie M Droin, Hui Cao, Pranita Kaphle, Kathryn E Dickerson, Kirthi R Kumar, Mingyi Chen, Weina Chen, Eric Solary, Peter Ly, Jian Zhou, Jian Xu.

Structural variants (SVs) involving enhancer hijacking can rewire chromatin topologies to cause oncogene activation in human cancers including hematologic malignancies; however, due to the lack of tools to assess their effects on gene regulation and chromatin organization, the molecular determinants for the functional output of enhancer hijacking remain poorly understood. Here, we developed a multimodal approach to integrate genome sequencing, chromosome conformation, chromatin state, and transcriptomic alteration for quantitative analysis of transcriptional effects and structural reorganization imposed by SVs in leukemic genomes. We identified known and new pathogenic SVs including recurrent t(5;14) translocations that cause the hijacking of BCL11B enhancers for the allele-specific activation of TLX3 in a subtype of pediatric leukemia. Epigenetic perturbation of SV-hijacked BCL11B enhancers impairs TLX3 transcription required for the growth of t(5;14) leukemia cells. By CRISPR engineering of patient-derived t(5;14) in isogenic leukemia cells, we uncovered a new mechanism whereby the transcriptional output of SV-induced BCL11B enhancer hijacking is dependent on the loss of DNA hypermethylation at the TLX3 promoter. Our results highlight the importance of the cooperation between genetic alteration and permissive chromatin as a critical determinant of SV-mediated oncogene activation, with implications for understanding aberrant gene transcription following epigenetic therapies in leukemia patients. Hence, leveraging the interdependency of genetic alteration on chromatin variation may provide new opportunities to reprogram gene regulation as targeted interventions in human disease.

DOI: https://doi.org/10.1182/blood.2022017555
Blood. 2023 Mar 22. pii: blood.2022017152. [Epub ahead of print]

ALWAYS STRESSED BUT NEVER EXHAUSTED: HOW STEM CELLS IN MYELOID NEOPLASMS AVOID EXTINCTION IN INFLAMMATORY CONDITIONS.

Helong Gary Zhao, Michael W Deininger.

Chronic or recurrent episodes of acute inflammation cause attrition of normal hematopoietic stem cells (HSCs) that can lead to hematopoietic failure, but they drive progression in myeloid malignancies and their precursor clonal hematopoiesis (CH). Mechanistic parallels exist between hematopoiesis in chronic inflammation and the continuously increased proliferation of myeloid malignancies, particularly myeloproliferative neoplasms (MPNs). The ability to enter dormancy, a state of deep quiescence characterized by low oxidative phosphorylation, low glycolysis, reduced protein synthesis, and increased autophagy is central to the preservation of long term HSCs and likely MPN SCs. The metabolic features of dormancy resemble those of diapause, a state of arrested embryonic development triggered by adverse environmental conditions. To outcompete their normal counterparts in the inflammatory MPN environment, MPN SCs co-opt mechanisms used by HSCs to avoid exhaustion, including signal attenuation by negative regulators, insulation from activating cytokine signals, anti-inflammatory signaling, and epigenetic reprogramming. We propose that new therapeutic strategies may be derived from conceptualizing myeloid malignancies as an ecosystem out of balance, where residual normal and malignant hematopoietic cells interact in multiple ways, only few of which have been characterized in detail. Disrupting MPN SC insulation to overcome dormancy, interfering with aberrant cytokines circuits that favor MPN cells and directly boosting residual normal HSCs are potential strategies to tip the balance in favor of normal hematopoiesis. While eradicating the malignant cell clones remains the goal of therapy, this may be a more attainable objective in the short term.

DOI: https://doi.org/10.1182/blood.2022017152
Expert Rev Hematol. 2023 Mar 23.

Identifying prognostic gene panels in acute myeloid leukemia.

Joaquin Sanchez-Garcia, Josefina Serrano, Esther Prados de La Torre, Juana Serrano-López, Clara Aparicio-Perez, E Barragán, Pau Montesinos.

   INTRODUCTION: Acute myeloid leukemia (AML) is a heterogeneous disease currently including 12 entities defined by genetic findings with remarkable differences in prognosis and targeted therapies availability. Therefore, identification of genetic abnormalities by efficient techniques have become a necessary tool in routine clinical practice for AML patients.
AREAS COVERED: In the present review we will focus on our current knowledge of relevant prognosis gene mutations in AML, as recently updated by European Leukemia Net Leukemia risk classification.
EXPERT OPINION: About 25% of newly diagnosed younger AML patients will be promptly classified as favorable prognosis by demonstrating the presence of NPM1 mutations or CBF rearrangements by qRT-PCR, allowing for implementing molecular measurable residual disease guided chemotherapy-based protocols. In fit AML patients rapid detection of FLT3-ITD is mandatory to associate midostaurin or quizartinib to treatment and assignment to intermediate prognosis. Conventional cytogenetics and FISH still have a role for detection adverse prognosis karyotypes and KMT2A, MECOM or NUP98 gene rearrangements. Further genetic characterization is done with NGS panels including favorable prognosis gene CEBPA bZIP and adverse prognosis genes, such as TP53 and myelodysplasia associated genes. Novel affordable and rapid NGS strategies are needed to satisfy the increasing complexity of prognosis characterization of AML.

Keywords:  AML; FLT3; NPM1; TP53; prognosis; splicesosome; targeted therapy

DOI:  https://doi.org/10.1080/17474086.2023.2193322
Blood Adv. 2023 Mar 22. pii: bloodadvances.2022008578. [Epub ahead of print]

Utility of Targeted Gene Sequencing to Differentiate Myeloid Malignancies from other Cytopenic Conditions.

Amy E DeZern, Johannes B Goll, R Coleman Lindsley, Rafael Bejar, Steffanie H Wilson, Donnie Hebert, H Joachim Deeg, Ling Zhang, Steven D Gore, Tareq Al Baghdadi, Jaroslaw P Maciejewski, Jane Jijun Liu, Eric Padron, Rami S Komrokji, Wael Saber, Gregory A Abel, Steven H Kroft, Alexandra M Harrington, Tyler Grimes, Harrison H Vaughn Reed, Robert S Fulton, Nancy L DiFronzo, Nancy Gillis, Mikkael A Sekeres, Matthew J Walter.

The National Heart, Lung, and Blood Institute National MDS Natural History Study (NCT02775383) is a prospective cohort study enrolling cytopenic patients with suspected myelodysplastic syndromes (MDS) to evaluate factors associated with disease. Here, we sequenced 53 genes in bone marrow samples harvested from 1,298 patients diagnosed with myeloid malignancy, including MDS and non-MDS myeloid malignancy, or alternative marrow conditions with cytopenia based on concordance between independent histopathologic reviews (local, centralized, and tertiary to adjudicate disagreements when needed). We developed a novel two-stage diagnostic classifier based on mutational profiles in 18 of 53 sequenced genes that were sufficient to best (1) predict a diagnosis of myeloid malignancy and (2) within those with a predicted myeloid malignancy, predict whether they had MDS. The classifier achieved a PPV of 0.84 and NPV of 0.8 with an AUROC of 0.85 when classifying patients as myeloid vs. no myeloid malignancy based on VAFs in 17 genes and a PPV of 0.71 and NPV of 0.64 with an AUROC of 0.73 when classifying patients as MDS vs. non-MDS malignancy based on VAFs in 10 genes. We next assessed how this approach could complement histopathology to improve diagnostic accuracy. For 99 of 139 (71%) patients (PPV of 0.83 and NPV of 0.65) with local and centralized histopathologic disagreement in myeloid vs. no myeloid malignancy, the classifier-predicted diagnosis agreed with the tertiary pathology review (considered the internal gold standard). An online version of the classifier that can be used with either VAFs or binary mutation profiles is available at https://thenationalmdsstudy.net.

DOI: https://doi.org/10.1182/bloodadvances.2022008578
Blood. 2023 Mar 23. pii: blood.2022019425. [Epub ahead of print]

The Clinical Picture of the ERCC6L2 Disease - from Bone Marrow Failure to Acute Leukemia.

Marja Hakkarainen, Ilse Kaaja, Suvi P M Douglas, Thomas J Vulliamy, Inderjeet Dokal, Jean Soulier, Lise Larcher, Régis Peffault de Latour, Thierry M Leblanc, Flore Sicre de Fontbrune, Timo Siitonen, Olli Lohi, Eva Hellström-Lindberg, Gisela Barbany, Bianca Tesi, Akiko Shimamura, Fabian Beier, Sharon Rosalie Jackson, Amir Kuperman, Tzipora C Falik Zaccai, Hannah Tamary, Cristina Mecucci, Ilaria Capolsini, Kirsi Jahnukainen, Urpu Salmenniemi, Riitta Niinimäki, Teppo Varilo, Outi Kilpivaara, Ulla Wartiovaara-Kautto.

Biallelic germline ERCC6L2 variants strongly predispose to bone marrow failure (BMF) and myeloid malignancies characterized by somatic TP53-mutated clones and erythroid predominance. We present a series of 52 subjects (35 families) with ERCC6L2 biallelic germline variants collected retrospectively in 11 centers globally, including follow-up of 1165 person-years. At initial investigations, 32 individuals were diagnosed with BMF and 15 with a hematological malignancy (HM). Subjects presented with 19 different variants across ERCC6L2, and we identified a founder mutation c.1424delT in the Finnish patients. The median age of subjects at baseline was 18 years (range 2-65). Changes in complete blood count (CBC) were mild despite severe bone marrow hypoplasia and somatic TP53 mutations, with no significant difference between subjects with or without (HM). Signs of a progressive disease were increasing TP53 variant allele frequency, dysplasia in megakaryocytes and/or erythroid lineage, and erythroid predominance in bone marrow morphology. The median age at onset of HM was 37.0 years (95% CI: 31.5-42.5; range 12-65). Overall survival (OS) at 3 years was 95% (95% CI: 85-100) and 19% (95% CI: 0-39) for patients with BMF and HM, respectively. Patients with myelodysplastic syndrome or acute myeloid leukemia with mutated TP53 undergoing hematopoietic stem cell transplantation had a poor outcome: 3-year OS is 28% (95% CI: 0-61). Our results demonstrate the importance of early recognition and active surveillance of patients with biallelic germline ERCC6L2 variants.

DOI: https://doi.org/10.1182/blood.2022019425
Proc Natl Acad Sci U S A. 2023 Mar 28. 120(13): e2210796120

Redox metabolism maintains the leukemogenic capacity and drug resistance of AML cells.

Dan Huang, Changcheng Zhang, Ming Xiao, Xie Li, Weicai Chen, Yu Jiang, Yamin Yuan, Yaping Zhang, Yejun Zou, Lei Deng, Yang Wang, Yuying Sun, Wenping Dong, Zhuo Zhang, Li Xie, Zhuo Yu, Chiqi Chen, Ligen Liu, Jing Wang, Yi Yang, Jie Yang, Yuzheng Zhao, Junke Zheng.

  Rewiring of redox metabolism has a profound impact on tumor development, but how the cellular heterogeneity of redox balance affects leukemogenesis remains unknown. To precisely characterize the dynamic change in redox metabolism in vivo, we developed a bright genetically encoded biosensor for H2O2 (named HyPerion) and tracked the redox state of leukemic cells in situ in a transgenic sensor mouse. A H2O2-low (HyPerion-low) subset of acute myeloid leukemia (AML) cells was enriched with leukemia-initiating cells, which were endowed with high colony-forming ability, potent drug resistance, endosteal rather than vascular localization, and short survival. Significantly high expression of malic enzymes, including ME1/3, accounted for nicotinamide adenine dinucleotide phosphate (NADPH) production and the subsequent low abundance of H2O2. Deletion of malic enzymes decreased the population size of leukemia-initiating cells and impaired their leukemogenic capacity and drug resistance. In summary, by establishing an in vivo redox monitoring tool at single-cell resolution, this work reveals a critical role of redox metabolism in leukemogenesis and a potential therapeutic target.

Keywords:  AML; H2O2 biosensor; drug resistance; leukemia-initiating cells; redox metabolism

DOI:  https://doi.org/10.1073/pnas.2210796120
Cell Rep. 2023 Mar 23. pii: S2211-1247(23)00315-7. [Epub ahead of print]42(4): 112304

Temporal multimodal single-cell profiling of native hematopoiesis illuminates altered differentiation trajectories with age.

Anna Konturek-Ciesla, Parashar Dhapola, Qinyu Zhang, Petter Säwén, Haixia Wan, Göran Karlsson, David Bryder.

  Aging negatively affects hematopoiesis, with consequences for immunity and acquired blood cell disorders. Although impairments in hematopoietic stem cell (HSC) function contribute to this, the in vivo dynamics of such changes remain obscure. Here, we integrate extensive longitudinal functional assessments of HSC-specific lineage tracing with single-cell transcriptome and epitope profiling. In contrast to recent suggestions from single-cell RNA sequencing alone, our data favor a defined structure of HSC/progenitor differentiation that deviates substantially from HSC-derived hematopoiesis following transplantation. Native age-dependent attrition in HSC differentiation manifests as drastically reduced lymphoid output through an early lymphoid-primed progenitor (MPP Ly-I). While in vitro activation fails to rescue lymphoid differentiation from most aged HSCs, robust lymphopoiesis can be achieved by culturing elevated numbers of candidate HSCs. Therefore, our data position rare chronologically aged HSC clones, fully competent at producing lymphoid offspring, as a prime target for approaches aimed to improve lymphopoiesis in the elderly.

Keywords:  CITE-seq; CP: Cell biology; aging; hematopoietic progenitors; hematopoietic stem cells; in vitro culture; lineage tracing; scRNA-seq

DOI:  https://doi.org/10.1016/j.celrep.2023.112304
Proc Natl Acad Sci U S A. 2023 Mar 28. 120(13): e2300054120

Cryo-EM analyses of KIT and oncogenic mutants reveal structural oncogenic plasticity and a target for therapeutic intervention.

Stefan G Krimmer, Nicole Bertoletti, Yoshihisa Suzuki, Luka Katic, Jyotidarsini Mohanty, Sheng Shu, Sangwon Lee, Irit Lax, Wei Mi, Joseph Schlessinger.

  The receptor tyrosine kinase KIT and its ligand stem cell factor (SCF) are required for the development of hematopoietic stem cells, germ cells, and other cells. A variety of human cancers, such as acute myeloid leukemia, gastrointestinal stromal tumor, and mast cell leukemia, are driven by somatic gain-of-function KIT mutations. Here, we report cryo electron microscopy (cryo-EM) structural analyses of full-length wild-type and two oncogenic KIT mutants, which show that the overall symmetric arrangement of the extracellular domain of ligand-occupied KIT dimers contains asymmetric D5 homotypic contacts juxtaposing the plasma membrane. Mutational analysis of KIT reveals in D5 region an "Achilles heel" for therapeutic intervention. A ligand-sensitized oncogenic KIT mutant exhibits a more comprehensive and stable D5 asymmetric conformation. A constitutively active ligand-independent oncogenic KIT mutant adopts a V-shaped conformation solely held by D5-mediated contacts. Binding of SCF to this mutant fully restores the conformation of wild-type KIT dimers, including the formation of salt bridges responsible for D4 homotypic contacts and other hallmarks of SCF-induced KIT dimerization. These experiments reveal an unexpected structural plasticity of oncogenic KIT mutants and a therapeutic target in D5.

Keywords:  cell signaling; cryo-EM; mechanism of activation; oncogenic mutant; receptor tyrosine kinase

DOI:  https://doi.org/10.1073/pnas.2300054120
Cell Death Dis. 2023 Mar 24. 14(3): 209

Type I interferon signaling in malignant blasts contributes to treatment efficacy in AML patients.

Peter Holicek, Iva Truxova, Jana Rakova, Cyril Salek, Michal Hensler, Marek Kovar, Milan Reinis, Romana Mikyskova, Josef Pasulka, Sarka Vosahlikova, Hana Remesova, Iva Valentova, Daniel Lysak, Monika Holubova, Petr Kaspar, Jan Prochazka, Lenka Kasikova, Radek Spisek, Lorenzo Galluzzi, Jitka Fucikova.

While type I interferon (IFN) is best known for its key role against viral infection, accumulating preclinical and clinical data indicate that robust type I IFN production in the tumor microenvironment promotes cancer immunosurveillance and contributes to the efficacy of various antineoplastic agents, notably immunogenic cell death inducers. Here, we report that malignant blasts from patients with acute myeloid leukemia (AML) release type I IFN via a Toll-like receptor 3 (TLR3)-dependent mechanism that is not driven by treatment. While in these patients the ability of type I IFN to stimulate anticancer immune responses was abolished by immunosuppressive mechanisms elicited by malignant blasts, type I IFN turned out to exert direct cytostatic, cytotoxic and chemosensitizing activity in primary AML blasts, leukemic stem cells from AML patients and AML xenograft models. Finally, a genetic signature of type I IFN signaling was found to have independent prognostic value on relapse-free survival and overall survival in a cohort of 132 AML patients. These findings delineate a clinically relevant, therapeutically actionable and prognostically informative mechanism through which type I IFN mediates beneficial effects in patients with AML.

DOI: https://doi.org/10.1038/s41419-023-05728-w
NPJ Precis Oncol. 2023 Mar 24. 7(1): 32

Prediction model for drug response of acute myeloid leukemia patients.

Quang Thinh Trac, Yudi Pawitan, Tian Mou, Tom Erkers, Päivi Östling, Anna Bohlin, Albin Österroos, Mattias Vesterlund, Rozbeh Jafari, Ioannis Siavelis, Helena Bäckvall, Santeri Kiviluoto, Lukas M Orre, Mattias Rantalainen, Janne Lehtiö, Sören Lehmann, Olli Kallioniemi, Trung Nghia Vu.

Despite some encouraging successes, predicting the therapy response of acute myeloid leukemia (AML) patients remains highly challenging due to tumor heterogeneity. Here we aim to develop and validate MDREAM, a robust ensemble-based prediction model for drug response in AML based on an integration of omics data, including mutations and gene expression, and large-scale drug testing. Briefly, MDREAM is first trained in the BeatAML cohort (n = 278), and then validated in the BeatAML (n = 183) and two external cohorts, including a Swedish AML cohort (n = 45) and a relapsed/refractory acute leukemia cohort (n = 12). The final prediction is based on 122 ensemble models, each corresponding to a drug. A confidence score metric is used to convey the uncertainty of predictions; among predictions with a confidence score >0.75, the validated proportion of good responders is 77%. The Spearman correlations between the predicted and the observed drug response are 0.68 (95% CI: [0.64, 0.68]) in the BeatAML validation set, -0.49 (95% CI: [-0.53, -0.44]) in the Swedish cohort and 0.59 (95% CI: [0.51, 0.67]) in the relapsed/refractory cohort. A web-based implementation of MDREAM is publicly available at https://www.meb.ki.se/shiny/truvu/MDREAM/ .

DOI: https://doi.org/10.1038/s41698-023-00374-z
Ann Hematol. 2023 Mar 21.

Lycorine induces apoptosis of acute myeloid leukemia cells and inhibits triglyceride production via binding and targeting FABP5.

Xinming Liang, Wenli Fu, YuHui Peng, Juanjuan Duan, Ting Zhang, Daogui Fan, Wei Hong, Xiaolan Qi, ChangXue Wu, Yan He, Wenfeng Yu, Jing Zhou, Pengxiang Guo, Hua Bai, Qifang Zhang.

  Acute myeloid leukemia (AML) is the most common hematopoietic malignancy with abnormal lipid metabolism. However, currently available information on the involvement of the alterations in lipid metabolism in AML development is limited. In this study, we demonstrate that FABP5 expression facilitates AML cell viability, protects AML cells from apoptosis, and maintains triglyceride production. Our bioinformatics analysis revealed that FABP5 expression was upregulated and correlated with unfavorable overall survival of AML patients. FABP5 expression may be used to distinguish normal and AML with high accuracy. FABP5-based risk score was an independent risk factor for AML patients. AML patients with highly expressed FABP5 predicted resistance to drugs. In vitro study showed that FABP5 expression was remarkably elevated in primary AML blasts and an AML cell line. Silencing FABP5 expression attenuated AML cell viability, reduced triglyceride production and lipid droplet accumulation, and induced apoptosis. We utilized AutoDock online tool to identify lycorine as an FABP5 inhibitor by binding FABP5 at amino acid residues Ile54, Thr56, Thr63, and Arg109. Lycorine treatment downregulated the expression levels of FABP5 and its target PPARγ, impaired AML cell viability, triggered apoptosis, and reduced triglyceride production in AML cells. These results demonstrate that FABP5 is critical for AML cell survival and highlight a novel metabolic vulnerability for AML.

Keywords:  Acute myeloid leukemia; Apoptosis; Cell viability; FABP5; Lycorine; Triglyceride

DOI:  https://doi.org/10.1007/s00277-023-05169-7
Cell Stem Cell. 2023 Mar 16. pii: S1934-5909(23)00071-1. [Epub ahead of print]

Hematopoietic stem cells preferentially traffic misfolded proteins to aggresomes and depend on aggrephagy to maintain protein homeostasis.

Bernadette A Chua, Connor J Lennan, Mary Jean Sunshine, Daniela Dreifke, Ashu Chawla, Eric J Bennett, Robert A J Signer.

  Hematopoietic stem cells (HSCs) regenerate blood cells throughout life. To preserve their fitness, HSCs are particularly dependent on maintaining protein homeostasis (proteostasis). However, how HSCs purge misfolded proteins is unknown. Here, we show that in contrast to most cells that primarily utilize the proteasome to degrade misfolded proteins, HSCs preferentially traffic misfolded proteins to aggresomes in a Bag3-dependent manner and depend on aggrephagy, a selective form of autophagy, to maintain proteostasis in vivo. When autophagy is disabled, HSCs compensate by increasing proteasome activity, but proteostasis is ultimately disrupted as protein aggregates accumulate and HSC function is impaired. Bag3-deficiency blunts aggresome formation in HSCs, resulting in protein aggregate accumulation, myeloid-biased differentiation, and diminished self-renewal activity. Furthermore, HSC aging is associated with a severe loss of aggresomes and reduced autophagic flux. Protein degradation pathways are thus specifically configured in young adult HSCs to preserve proteostasis and fitness but become dysregulated during aging.

Keywords:  Bag3; aggrephagy; aggresome; aging; autophagy; hematopoietic stem cell; proteasome; protein degradation; proteostasis; stem cell

DOI:  https://doi.org/10.1016/j.stem.2023.02.010
Haematologica. 2023 Mar 23.

Molecular targeting of the UDP-glucuronosyltransferase enzymes in high-eukaryotic translation initiation factor 4E refractory/relapsed acute myeloid leukemia patients: a randomized phase II trial of vismodegib, ribavirin with or without decitabine.

Sarit Assouline, Jadwiga Gasiorek, Julie Bergeron, Caroline Lambert, Biljana Culjkovic-Kraljacic, Eftihia Cocolakis, Chadi Zakaria, David Szlachtycz, Karen Yee, Katherine L B Borden.

Drug resistance underpins poor outcomes in many malignancies including refractory and relapsed acute myeloid leukemia (R/R AML). Glucuronidation is a common mechanism of drug inactivation impacting many AML therapies e.g. cytarabine, decitabine, azacytidine and venetoclax. In AML cells, the capacity for glucuronidation arises from increased production of the UDP-glucuronosyltransferase 1A (UGT1A) enzymes. UGT1A elevation was first observed in AML patients who relapsed after response to ribavirin, a drug used to target the eukaryotic translation initiation factor eIF4E, and subsequently in patients who relapsed on cytarabine. UGT1A elevation resulted from increased expression of the sonic-hedgehog transcription factor GLI1. Vismodegib inhibited GLI1, decreased UGT1A levels, reduced glucuronidation of ribavirin and cytarabine and re-sensitized cells to these drugs. Here, we examined if UGT1A protein levels, and thus glucuronidation activity, were targetable in humans and if this corresponded to clinical response. We conducted a Phase II trial using vismodegib with ribavirin, with or without decitabine, in largely heavily pretreated patients with high-eIF4E AML. Pre-therapy molecular assessment of patients' blasts indicated highly elevated UGT1A levels relative to healthy volunteers. Among patients with partial response, blast response or prolonged stable disease, vismodegib reduced UGT1A levels which corresponded to effective targeting of eIF4E by ribavirin. In all, our studies are the first to demonstrate that UGT1A protein, and thus glucuronidation, are targetable in humans. These studies pave the way for the development of therapies that impair glucuronidation, one of the most common drug deactivation modalities.

DOI: https://doi.org/10.3324/haematol.2023.282791
Am J Blood Res. 2023 ;13(1): 28-43

Prognostic relevance of NPM1, CEBPA, and FLT3 mutations in cytogenetically normal adult AML patients.

Aparna Ningombam, Deepak Verma, Rajive Kumar, Jay Singh, M Shadab Ali, Avanish Kumar Pandey, Inder Singh, Sameer Bakhshi, Atul Sharma, Deepam Pushpam, Jayanth Kumar Palanichamy, Pranay Tanwar, Amar Ranjan Singh, Anita Chopra.

BACKGROUND: Acute myeloid leukemia with normal cytogenetics (CN-AML) is the largest group of AML patients with very heterogenous patient outcomes. The revised World Health Organization classification of the hematolymphoid tumours, 2022, has incorporated AML with Nucleophosphmin1 (NPM1) and CCAAT/enhancer binding protein-alpha (CEBPA) mutations as distinct entities. Despite the existing evidence of the prognostic relevance of FMS-like tyrosine kinase-3 internal tandem duplication (FLT3-ITD) in AML, it has not been included in the revised classification.
METHOD: In this prospective study, we determined the prevalence of NPM1, CEBPA, and FLT3 gene mutations in 151 de novo CN-AML adult patients (age ≥18 years) in a tertiary care hospital in north India. Additionally, the prognostic relevance of these mutations was also evaluated.
RESULTS: NPM1, FLT3-ITD, and CEBPA mutations were found in 33.11%, 23.84%, and 15.77% of CN-AML patients, respectively. CEBPA mutations were found at 3 domains: transactivation domain 1 (TAD1) in 10 (6.62%), transactivation domain 2 (TAD2) in 5 (3.31%), and basic leucine zipper domain (bZIP) in 11 (7.82%) patients. Patients with NPM1 mutation had better clinical remission rate (CR) (P=0.003), event-free survival (P=0.0014), and overall survival (OS) (P=0.0017). However, FLT3-ITD and CEBPA mutations did not show any association with CR (P=0.404 and 0.92, respectively). Biallelic CEBPA mutations were found in 12 (7.95%) patients and were associated with better OS (P=0.043).
CONCLUSIONS: These findings indicate that NPM1 and CEBPA mutations can be precisely used for risk stratification in CN-AML patients.

Keywords: CEBPA; CN-AML; FLT3; NPM1; mutations; prognosis
Nat Cardiovasc Res. 2023 Jan 16. 2 144-158

TP53-mediated clonal hematopoiesis confers increased risk for incident atherosclerotic disease.

Seyedeh M Zekavat, Vanesa Viana-Huete, Nuria Matesanz, Saman Doroodgar Jorshery, María A Zuriaga, Md Mesbah Uddin, Mark Trinder, Kaavya Paruchuri, Virginia Zorita, Alba Ferrer-Pérez, Marta Amorós-Pérez, Paolo Kunderfranco, Roberta Carriero, Carolina M Greco, Alejandra Aroca-Crevillen, Andrés Hidalgo, Scott M Damrauer, Christie M Ballantyne, Abhishek Niroula, Christopher J Gibson, James Pirruccello, Gabriel Griffin, Benjamin L Ebert, Peter Libby, Valentín Fuster, Hongyu Zhao, Marzyeh Ghassemi, Pradeep Natarajan, Alexander G Bick, José J Fuster, Derek Klarin.

  Somatic mutations in blood indicative of clonal hematopoiesis of indeterminate potential (CHIP) are associated with an increased risk of hematologic malignancy, coronary artery disease, and all-cause mortality. Here we analyze the relation between CHIP status and incident peripheral artery disease (PAD) and atherosclerosis, using whole-exome sequencing and clinical data from the UK Biobank and Mass General Brigham Biobank. CHIP associated with incident PAD and atherosclerotic disease across multiple beds, with increased risk among individuals with CHIP driven by mutation in DNA Damage Repair (DDR) genes such as TP53 and PPM1D. To model the effects of DDR-induced CHIP on atherosclerosis, we used a competitive bone marrow transplantation strategy, and generated atherosclerosis-prone Ldlr-/- chimeric mice carrying 20% p53-deficient hematopoietic cells. The chimeric mice were analyzed 13-weeks post-grafting and showed increased aortic plaque size and accumulation of macrophages within the plaque, driven by increased proliferation of p53-deficient plaque macrophages. In summary, our findings highlight the role of CHIP as a broad driver of atherosclerosis across the entire arterial system beyond the coronary arteries, and provide genetic and experimental support for a direct causal contribution of TP53-mutant CHIP to atherosclerosis.

Keywords:  atherosclerosis; clonal hematopoiesis; sequencing; somatic

DOI:  https://doi.org/10.1038/s44161-022-00206-6
Cancer. 2023 Mar 21.

Clinical characteristics and outcomes of children with newly diagnosed acute myeloid leukemia and hyperleukocytosis managed with different cytoreductive methods.

Georgios E Christakopoulos, Kendra N Walker, Jesse Smith, Clifford M Takemoto, Yan Zheng, Ching-Hon Pui, Raul C Ribeiro, Lei Wang, Stanley B Pounds, Jeffrey E Rubnitz, Hiroto Inaba.

   BACKGROUND: Hyperleukocytosis in patients with acute myeloid leukemia (AML) has been associated with worse outcomes. For cytoreduction, leukapheresis has been used but its clinical utility is unknown, and low-dose cytarabine (LD-cytarabine) is used as an alternative method.
METHODS: Children with newly diagnosed AML treated between 1997 and 2017 in institutional protocols were studied. Hyperleukocytosis was defined as a leukocyte count of ≥100 × 109 /L at diagnosis. Clinical characteristics, early complications, survival data, and effects of cytoreductive methods were reviewed. Among 324 children with newly diagnosed AML, 49 (15.1%) presented with hyperleukocytosis. Initial management of hyperleukocytosis included leukapheresis or exchange transfusion (n = 16, considered as one group), LD-cytarabine (n = 18), hydroxyurea (n = 1), and no leukoreduction (n = 14).
RESULTS: Compared with patients who received leukapheresis, the percentage decrease in leukocyte counts following intervention was greater among those who received LD-cytarabine (48% vs. 75%; p = .02), with longer median time from diagnosis to initiation of protocol therapy (28.1 vs. 95.2 hours; p < .001). The incidence of infection was higher in patients (38%) who had leukapheresis than those who receive LD-cytarabine (0%) or leukoreduction with protocol therapy (14%) (p = .008). No differences were noted in the outcomes among the intervention groups. Although patients with hyperleukocytosis had higher incidences of pulmonary and metabolic complications than did those without, no early deaths occurred, and the complete remission, event-free survival, overall survival rates, and outcomes of both groups were similar.
CONCLUSION: LD-cytarabine treatment appears to be a safe and effective means of cytoreduction for children with AML and hyperleukocytosis.

Keywords:  AML; chemotherapy; cytoreduction; hyperleukocytosis; leukapheresis

DOI:  https://doi.org/10.1002/cncr.34751
Br J Haematol. 2023 Mar 23.

A miRNA signature related to stemness identifies high-risk patients in paediatric acute myeloid leukaemia.

Elena Esperanza-Cebollada, Soledad Gómez-González, Sara Perez-Jaume, Nerea Vega-García, Clara Vicente-Garcés, Mercè Richarte-Franqués, Susana Rives, Albert Català, Montserrat Torrebadell, Mireia Camós.

  Clinical and biological variables like genetic aberrations at diagnosis and the levels of measurable residual disease (MRD) are the most powerful biomarkers to predict the outcome of paediatric leukaemia. Recently, a model integrating the genetic abnormalities, transcriptional identity, and leukaemia stemness measured as leukaemic stem cell score (pLSC6) has been proposed to identify high-risk paediatric acute myeloid leukaemia (AML) patients. However, the role of epigenetics in defining prognosis still needs to be established. We evaluated the role of 89 miRNAs regulating stemness and their contribution to predicting outcomes in 110 paediatric patients with acute leukaemia. We identified a 24-miRNA signature capable of distinguishing paediatric AML patients with excellent or poor outcomes. We validated these results in an independent cohort using public repository-based data. The 24-miRNA signature was significantly associated with the leukaemic stemness scores and the underlying genetics of patients. Notably, the combination of classical prognostic factors (MRD and genetics), the pLSC6 score and the 24-miRNA signature had a higher capacity to predict the overall and event-free survival than each variable individually. Our 24-miRNA signature provides epigenetic data to integrate into genetics, MRD and stemness-related leukaemic scores to refine risk stratification in paediatric AML patients.

Keywords:  miRNA; paediatric acute myeloid leukaemia; prognosis; stemness

DOI:  https://doi.org/10.1111/bjh.18746
Res Sq. 2023 Mar 09. pii: rs.3.rs-2656206. [Epub ahead of print]

Novel Scheme for Defining the Clinical Implications of TP53 Mutations in Myeloid Neoplasia.

Waled Bahaj, Tariq Kewan, Carmelo Gurnari, Arda Durmaz, Ben Ponvilawan, Ishani Pandit, Yasuo Kubota, Olisaemeka D Ogbue, Misam Zawit, Yazan Madanat, Taha Bat, Suresh K Balasubramanian, Hussein Awada, Ramsha Ahmed, Minako Mori, Manja Meggendorfer, Torsten Haferlach, Valeria Visconte, Jaroslaw P Maciejewski.

Background:TP53 mutations ( TP53 MT ) occur in diverse genomic configurations. Particularly, biallelic inactivation is associated with poor overall survival in cancer. Lesions affecting only one allele might not be directly leukemogenic, questioning the presence of cryptic biallelic subclones in cases with dismal prognosis. Methods: We have collected clinical and molecular data of 7400 patients with myeloid neoplasms and applied a novel model to properly resolve the allelic configuration of TP53 MT and assess prognosis more precisely. Results: Overall, TP53 MT were found in 1010 patients. Following the traditional criteria, 36% of cases were classified as single hits while 64% exhibited double hits genomic configuration. Using a newly developed molecular algorithm, we found that 579 (57%) patients had unequivocally biallelic, 239 (24%) likely contained biallelic, and 192 (19%) had most likely monoallelic TP53 MT . Such classification was further substantiated by a survival-based model built after re-categorization. Among cases traditionally considered monoallelic, the overall survival of those with probable monoallelic mutations was similar to the one of wild-type patients and was better than that of patients with a biallelic configuration. As a result, patients with certain biallelic hits, regardless of the disease subtype (AML or MDS), had a similar prognosis. Similar results were observed when the model was applied to an external cohort. These results were recapitulated by single-cell DNA studies, which unveiled the biallelic nature of previously considered monoallelic cases. Conclusion: Our novel approach more accurately resolves TP53 genomic configuration and uncovers genetic mosaicism for the use in the clinical setting to improve prognostic evaluation.

DOI: https://doi.org/10.21203/rs.3.rs-2656206/v1
Hematology. 2023 Dec;28(1): 2191462

Does leukocytosis remain a predictive factor for survival outcomes in patients with acute promyelocytic leukemia receiving ATRA plus a chemotherapy-based regimen? A prospective multicenter analysis from TALWG.

Smith Kungwankiattichai, Weerapat Owattanapanich, Thanawat Rattanathammethee, Ekarat Rattarittamrong, Chantiya Chanswangphuwana, Chantana Polprasert, Wasithep Limvorapitak, Supawee Saengboon, Pimjai Niparuck, Teeraya Puavilai, Jakrawadee Julamanee, Pirun Saelue, Chinadol Wanitpongpun, Kannadit Prayongratana, Chantarapa Sriswasdi, Chajchawan Nakhakes.

   INTRODUCTION: Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia (AML) with a unique clinical presentation and prognosis. This study aimed to investigate the epidemiology, clinical characteristics, treatments, and clinical outcomes of Thai APL patients dominantly treated with all-trans-retinoic acid (ATRA) combined with a chemotherapy-based therapy.
METHODS: This was an eight-year prospective, observational study from nine academic hospitals in the Thai Acute Leukemia Working Group (TALWG) of the Thai Society of Hematology, which included newly diagnosed Thai APL patients, aged 18 years or older. The web-based registration collected baseline charateristic, and clinical outcomes.
RESULTS: From 992 newly diagnosed AML patients, 79 APL patients were enrolled in this study. Almost all subjects were de novo APL (94.9%), while the others were therapy-related APL. The commonest clinical presentation was disseminated intravascular coagulation (38%). One-third of the patients were categorized as high risk according to the initial WBC. Almost all patients received ATRA combined with idarubicin regimen. The complete response rate was as high as 95.7%, which translated into excellent four-year overall survival (OS) (75.6%) and four-year leukemia-free survival (LFS) (75.4%). The multivariate analysis demonstrated that the older age and WBC count >20 × 109/L conferred a significantly unfavorable OS with the hazard ratios of 3.03 (95% confidence interval [CI]: 1.14-8.05) and 4.18 (95%CI: 1.69-10.35), respectively. Similarly, these two parameters remained independent of the poor prognosis factors for LFS.
CONCLUSION: This report confirmed that APL had a favorable prognosis. However, advanced age and high WBC count >20 × 109/L contributed to a worse outcome.
ABBREVIATIONS: APL; acute promyelocytic leukemia; ATRA; all-transretinoic acid; CR; complete remission; DS; differentiation syndrome; ECOG; Eastern Cooperative Oncology Group; ED; early death; HR; hazard ratio; IQR; interquartile range; LFS; leukemia-free survival; OS; overall survival; WBC; white blood cell.

Keywords:  APL; Acute promyelocytic leukemia; Thailand

DOI:  https://doi.org/10.1080/16078454.2023.2191462
Am J Hematol. 2023 Mar 20.

Clonal hematopoiesis of indeterminate potential and clonal cytopenias of undetermined significance: 2023 update on clinical associations and management recommendations.

Abhishek A Mangaonkar, Mrinal M Patnaik.

CONDITION OVERVIEW: Clonal hematopoiesis (CH) refers to age-associated expansion of somatic variants in hematopoietic stem and progenitor cells (HSPC).
DIAGNOSIS: CH of indeterminate potential (CHIP) is operationally defined as pathogenic variants in HSPCs at a variant allele frequency ≥ 2%.
CLINICAL ASSOCIATIONS: CH is associated with increased occurrence of several hematological conditions such as cytopenias (also called clonal cytopenia of undetermined significance), hematological (predominantly myeloid but also lymphoid) neoplasms, cytosis (including monocytosis), and non-hematological conditions such as atherosclerotic cardiovascular and cerebrovascular disease, ischemic congestive heart failure, venous thromboembolism, type 2 diabetes mellitus, chronic obstructive pulmonary disease, osteoporosis, gout, with a potential protective effect in Alzheimer's disease (AD).
MANAGEMENT RECOMMENDATIONS: As of now, there is limited prospective data for CH testing; however, CH detection is becoming increasingly prevalent due to ubiquitous use of somatic and germline NGS testing. This in addition to data suggesting that therapy related myeloid neoplasm (tMN) in many cases is preceded by the detection of CH clones, has led to the establishment of CH clinics at several institutions. At our institution, on a research basis, we currently recommend testing for CH for individuals with persistent (>4 months) unexplained cytopenias, in patients with malignancies prior to adjuvant cytotoxic chemotherapy and/or radiation or radionuclide therapy, screening prior to autologous hematopoietic stem cell transplantation and chimeric antigen receptor T cell (CAR-T) therapy and to assess as to whether or not, potential germline mosaic variants actually represent CH. This article is protected by copyright. All rights reserved.

DOI: https://doi.org/10.1002/ajh.26915
Expert Rev Hematol. 2023 Mar 21. 1-10

An evaluation of fedratinib for adult patients with newly diagnosed and previously treated myelofibrosis.

Khalil Saleh, Vincent Ribrag.

   INTRODUCTION: Myelofibrosis (MF) is a life-shortening myeloproliferative neoplasm that has multiple features such as clonal proliferation, fibrosis and splenomegaly. Until recently, ruxolitinib, a Janus Kinase (JAK) 1/2 inhibitor was the only targeted therapy approved for transplant-ineligible patients with MF and who require treatment for symptoms and/or splenomegaly. However, the discontinuation rate with ruxolitinib at 3 to 5 years is high and mostly due to loss of response or toxicity, and these patients had no subsequent treatment.
AREAS COVERED: Fedratinib, a selective JAK2 inhibitor, was approved by the Food and Drug Administration (FDA) in August 2019 for the treatment of intermediate-2 or high-risk primary or secondary MF, regardless of prior JAK inhibitor treatment for the management of symptoms and splenomegaly. We discuss herein the development of fedratinib and its pharmacology and pharmacokinetics as well as the clinical development and the future directions. We used PubMed for the search of articles related to fedratinib and myelofibrosis.
EXPERT OPINION: Fedratinib provided a second-line treatment for patients with MF who failed or discontinued ruxolitinib. New combinations of JAK inhibitors with other targeted therapies are a must in order to improve the management of MF.

Keywords:  JAK2; Myelofibrosis; fedratinib; momelotinib; navitoclax; pacritinib; prelabresib; ruxolitinib

DOI:  https://doi.org/10.1080/17474086.2023.2192473
Cancer Discov. 2023 Mar 23. OF1

Sequencing Identifies Relapse-Prone AML Patients.

For patients with acute myeloid leukemia, DNA sequencing before stem cell transplant can predict the chances of relapse, research shows. Scientists found that NPM1 alterations and/or FLT3 internal tandem duplications that persist after treatment and prior to a stem cell transplant were better predictors of relapse than flow cytometry.

DOI: https://doi.org/10.1158/2159-8290.CD-NB2023-0021
Leuk Res. 2023 Mar 10. pii: S0145-2126(23)00041-3. [Epub ahead of print]128 107056

10-year nationwide trends in incidence, treatment patterns, and mortality of patients with myelodysplastic syndromes in Denmark.

Tine Bichel Lauritsen, Jan Maxwell Nørgaard, Susanne Oksbjerg Dalton, Kirsten Grønbæk, Tarec Christoffer El-Galaly, Lene Sofie Granfeldt Østgård.

  Further temporal data on incidence, treatment patterns, and prognosis for patients with myelodysplastic syndromes (MDS) are needed. This study examined 10-year trends in incidence, treatment patterns, and all-cause mortality in a population-based cohort of 2309 MDS patients using Danish nationwide registries (2010-2019). We computed annual incidence rates overall and according to sex and age-groups. We examined temporal changes in the cumulative incidence of MDS specific treatments initiated within one year from diagnosis and temporal changes in the absolute risk of death and five-year adjusted hazard ratios (aHRs) for death, adjusting for age, sex and comorbidity. The age-standardized incidence rate of MDS per 100,000 person-years increased slightly from 5.3 in 2010 to 6.4 in 2019. Between 2010-2012 to 2016-2017, the use of azacitidine increased overall (8% to 22%), in patients with intermediate risk MDS (12% to 34%), and in patients with high-risk MDS (22% to 50%), while it remained stable (around 5%) for patients with low-risk MDS. The five-year aHR for death in the most recent calendar period compared to the earliest calendar period remained unchanged in patients with low-risk MDS, aHR = 0.90 (95% CI, 0.72-1.12) and in patients with high-risk MDS, aHR = 1.19 (95% CI, 0.89-1.61), while survival improved over time among patients with intermediate risk MDS, aHR = 0.67 (95% CI, 0.48-0.92). In conclusion the incidence of MDS slightly increased during a 10-year period in Denmark. The use of azacitidine increased markedly but five-year overall survival remained unchanged.

Keywords:  Incidence; MDS; Prognosis; Transfusion burden; Treatment

DOI:  https://doi.org/10.1016/j.leukres.2023.107056
Blood Adv. 2023 Mar 24. pii: bloodadvances.2023009765. [Epub ahead of print]

Improved Access to HCT with Reduced Racial Disparities Through Integration with Leukemia Care and Haploidentical Donors.

Asad Bashey, Xu Zhang, Lawrence E Morris, Henry Kent Holland, Lizamarie Bachier-Rodriguez, Scott R Solomon, Melhem M Solh.

Few patients with non-favorable risk (NFR) acute leukemia and MDS (AL/MDS) have historically accessed allogeneic transplantation (HCT). We assessed whether this can be improved by the integration of HCT/leukemia care and use of haploidentical donors (HID). Of 256 consecutive patients aged ≤75 who received initial therapy at our center for NFR AL/MDS from 2016 to 2021, 147 (57%) proceeded to planned HCT (70% for patients aged <60). On logistic regression analysis, age (OR 1.50 per 10-year increment, p<0.001), race- black vs white (OR 2.05, p=0.023), were significant factors for failure to receive HCT. Reasons for no HCT were: comorbidities (37%), poor KPS, lack of adequate caregiver support, refractory malignancy (19% each) and patient refusal (17%). Lack of donor or insurance were rarely cited (3% each). In older patients (≥60 years), comorbidities (49 vs. 15%, p<0.001) and KPS (25% vs. 10%, p=0.06) were more common reasons, and lack of caregiver support was less common (13% vs. 30%, p=0.031). In black vs. white patients, lack of caregivers (37% vs 11%, p=0.002) was more frequent. Median time from initial treatment to HCT was 118 days and was similar for black vs white patients (112 vs 122 days, p=0.80). On landmark analysis, HCT within 6 months of initial treatment resulted in better survival. On multivariable analysis, HCT resulted in a significant survival benefit (HR 0.60, p=0.020). With the above approach, the majority of currently treated patents aged ≤75 can access planned HCT. Black patients remain at higher risk for not receiving HCT.

DOI: https://doi.org/10.1182/bloodadvances.2023009765
EMBO Rep. 2023 Mar 21. e55373

pH regulates hematopoietic stem cell potential via polyamines.

Sachin Kumar, Jeffrey D Vassallo, Kalpana J Nattamai, Aishlin Hassan, Rebekah Karns, Angelika Vollmer, Karin Soller, Vadim Sakk, Mehmet Sacma, Travis Nemkov, Angelo D'Alessandro, Hartmut Geiger.

  Upon ex vivo culture, hematopoietic stem cells (HSCs) quickly lose potential and differentiate into progenitors. The identification of culture conditions that maintain the potential of HSCs ex vivo is therefore of high clinical interest. Here, we demonstrate that the potential of murine and human HSCs is maintained when cultivated for 2 days ex vivo at a pH of 6.9, in contrast to cultivation at the commonly used pH of 7.4. When cultivated at a pH of 6.9, HSCs remain smaller, less metabolically active, less proliferative and show enhanced reconstitution ability upon transplantation compared to HSC cultivated at pH 7.4. HSCs kept at pH 6.9 show an attenuated polyamine pathway. Pharmacological inhibition of the polyamine pathway in HSCs cultivated at pH 7.4 with DFMO mimics phenotypes and potential of HSCs cultivated at pH 6.9. Ex vivo exposure to a pH of 6.9 is therefore a positive regulator of HSC function by reducing polyamines. These findings might improve HSC short-term cultivation protocols for transplantation and gene therapy interventions.

Keywords:  DFMO; HSCs; ex vivo; pH; polyamine

DOI:  https://doi.org/10.15252/embr.202255373
Ann Hematol. 2023 Mar 24.

Multicenter retrospective analysis of clinical outcome of adult patients with mixed-phenotype acute leukemia treated with acute myeloid leukemia-like or acute lymphoblastic leukemia-like chemotherapy and impact of allogeneic stem cell transplantation: a Campus ALL study.

Davide Lazzarotto, Ilaria Tanasi, Antonella Vitale, Matteo Piccini, Michelina Dargenio, Fabio Giglio, Fabio Forghieri, Nicola Fracchiolla, Marco Cerrano, Elisabetta Todisco, Cristina Papayannidis, Matteo Leoncin, Marzia Defina, Fabio Guolo, Crescenza Pasciolla, Mario Delia, Patrizia Chiusolo, Antonino Mulè, Anna Candoni, Massimiliano Bonifacio, Giovanni Pizzolo, Robin Foà.

  Mixed-phenotype acute leukemia (MPAL) is a rare disease. Treatment is often similar to that of acute lymphoblastic leukemia (ALL), but the outcome in adults and the role of allogeneic stem cell transplantation (AlloSCT) are not well defined. We report on 77 adult patients diagnosed with MPAL over the last 10 years and treated with a curative intent. Median age was 49 years; 7.6% of cases had a BCR::ABL1 rearrangement. Thirty patients (39%) were treated with an acute myeloid leukemia (AML)-like induction and 47 (61%) with an ALL-like scheme. The complete remission (CR) rate was 67.6% and an ALL-like therapy was associated with a better CR rate (P = 0.048). The median OS was 41.9 months; age ≤ 60 years was associated with a better OS (67 vs 26 months, P = 0.014). An AlloSCT was performed in 50 patients (65%). The 5-year OS of transplanted patients was 54%. The OS post-AlloSCT was better in patients who were minimal residual disease (MRD)-negative prior to transplant (75.8% vs 45.2%, P = 0.06). This study shows that MPAL patients respond better to an ALL-like induction therapy; that consolidation therapy should include, whenever possible, an AlloSCT and that MRD negativity should be a primary endpoint of treatment.

Keywords:  Adults; Allogeneic stem cell transplantation; Minimal residual disease; Mixed-phenotype acute leukemia

DOI:  https://doi.org/10.1007/s00277-023-05162-0
Blood. 2023 Mar 23. 141(12): 1373-1374

Context is key for FLT3-ITD.

Sara E Meyer.

DOI: https://doi.org/10.1182/blood.2022019135