bims-tremyl 2023-08-27 papers

bims-tremyl

Biomed News

on Therapy resistance biology in myeloid leukemia

Issue of 2023‒08‒27
forty papers selected by
Paolo Gallipoli, Barts Cancer Institute, Queen Mary University of London

Phenotypic subtypes of leukaemic transformation in chronic myelomonocytic leukaemia.
Improved post-transplant outcomes in recent years for AML patients with FLT3-ITD and wild-type NPM1: a report from the EBMT acute leukemia working party.
Multiparameter prediction of myeloid neoplasia risk.
SUMOylation inhibitor TAK-981 (subasumstat) synergizes with 5-azacitidine in preclinical models of acute myeloid leukemia.
Glasdegib plus intensive or non-intensive chemotherapy for untreated acute myeloid leukemia: results from the randomized, phase 3 BRIGHT AML 1019 trial.
Convergent somatic evolution commences in utero in a germline ribosomopathy.
Modulation of Human Thrombopoietin Receptor Conformations Uncouples JAK2 V617F-Driven From Cytokine-Induced Activation.
Allogeneic Hematopoietic Cell Transplantation Improves Outcome in Myelodysplastic Syndrome Across High-Risk Genetic Subgroups: Genetic Analysis of the Blood and Marrow Transplant Clinical Trials Network 1102 Study.
Complementary and countervailing actions of Jak2 and Ikk2 in hematopoiesis in mice.
Genetic Predisposition to Clonal Hematopoiesis.
Acquired Resistance to Venetoclax plus Azacitidine in Acute Myeloid Leukemia: in vitro Models and Mechanisms.
Cell-free DNA measurable residual disease as a predictor of postallogeneic hematopoietic cell transplant outcomes.
Cell-free DNA 5-hydroxymethylcytosine is highly sensitive for MRD assessment in acute myeloid leukemia.
Safety and efficacy of FLAG-Ida-based therapy combined with venetoclax for the treatment for newly diagnosed and relapsed/refractory patients with AML - A systematic review.
Serum D-2-hydroxyglutarate and the ratio of D-2HG/L-2HG predict IDH mutation in acute myeloid leukemia.
Comparison of venetoclax and ivosidenib/enasidenib for unfit newly diagnosed patients with acute myeloid leukemia and IDH1/2 mutation: a network meta-analysis.
Therapeutic targeting of leukemia stem cells in acute myeloid leukemia.
Prognostic impact of FLT3-ITD mutation on NPM1+ acute myeloid leukaemia patients and related molecular mechanisms.
A Multicenter Retrospective Chart Review Study of Treatment and Disease Patterns and Clinical Outcomes of Patients with Chronic-Phase Chronic Myeloid Leukemia in Third-Line Treatment or with T315I Mutation.
Presence but not number of secondary type mutations influences outcome in de novo AML without MDS-associated or recurring cytogenetic abnormalities.
Base Editor Scanning Reveals Activating Mutations of DNMT3A.
Myeloablative Fractionated Busulfan for Allogeneic Stem Cell Transplant in Older Patients or Patients with Comorbidities.
An ETV6::NTRK3 fusion transcript in a core-binding factor acute myeloid leukemia.
Hematopoietic-specific heterozygous loss of Dnmt3a exacerbates colitis-associated colon cancer.
STX-478, a Mutant-Selective, Allosteric PI3Ka Inhibitor Spares Metabolic Dysfunction and Improves Therapeutic Response in PI3Ka-Mutant Xenografts.
Mutations in the bZip region of the CEBPA gene: A novel prognostic factor in patients with acute myeloid leukemia.
Recent advances in precision medicine for acute myeloid leukemia.
Next-generation sequencing of baseline genetic mutations and outcomes of eltrombopag and azacitidine therapy in patients with myelodysplastic syndromes and thrombocytopenia: Data from the SUPPORT clinical trial.
Dissecting the role of SWI/SNF component ARID1B in steady state hematopoiesis.
Comprehensive isotopomer analysis of glutamate and aspartate in small tissue samples.
How should we interpret conclusions of TKI-stopping studies.
Framework of clonal mutations concurrent with WT1 mutations in adults with acute myeloid leukemia: Alliance for Clinical Trials in Oncology study.
MLL-AF4 cooperates with PAF1 and FACT to drive high-density enhancer interactions in leukemia.
Autophagy preserves hematopoietic stem cells by restraining MTORC1-mediated cellular anabolism.
BCL2 inhibition reveals a dendritic cell-specific immune checkpoint that controls tumor immunosurveillance.
Lineage-specific detection of residual disease predicts relapse in chronic myeloid leukemia patients stopping therapy.
Favorable outcomes of NPM1mut AML patients are due to transcriptional inactivation of FOXM1, presenting a new target to overcome chemoresistance.
Evolutionary determinants of curability in cancer.
Non-cell-autonomous cancer progression from chromosomal instability.
Distinct mutational processes shape selection of MHC class I and class II mutations across primary and metastatic tumors.

Br J Haematol. 2023 Aug 22.

Phenotypic subtypes of leukaemic transformation in chronic myelomonocytic leukaemia.

Guillermo Montalban-Bravo, Rashmi Kanagal-Shamanna, Ziyi Li, Danielle Hammond, Kelly Chien, Juan Jose Rodriguez-Sevilla, Koji Sasaki, Elias Jabbour, Courtney DiNardo, Koichi Takahashi, Nicholas Short, Ghayas C Issa, Naveen Pemmaraju, Tapan Kadia, Farhad Ravandi, Naval Daver, Gautam Borthakur, Sanam Loghavi, Sherry Pierce, Carlos Bueso-Ramos, Hagop Kantarjian, Guillermo Garcia-Manero.

  Chronic myelomonocytic leukaemia (CMML) is a haematological disorder with high risk of transformation to acute myeloid leukaemia (AML). To characterize the phenotypic and genomic patterns of CMML progression, we evaluated a cohort of 189 patients with AML evolving from CMML. We found that transformation occurs through distinct trajectories characterized by genomic profiles and clonal evolution: monocytic (Mo-AML, 53%), immature myeloid (My-AML, 43%) or erythroid (Ery-AML, 2%). Mo-AML, characterized by expansion of monoblasts and promonocytes (low CD34, CD117 expression; high CD14, CD33, CD56 and CD64 expression), were defined by SRSF2, TET2 and RAS pathway mutation co-dominance and were more likely to evolve from SRSF2-TET2 co-mutant CMML through emergence/expansion of RAS pathway mutant clones. Conversely, My-AML, characterized by expansion of immature myeloid blasts (high frequency of CD34, CD38, CD117; low frequency of CD14, CD64 and CD56 expression) were less likely to exhibit SRSF2-TET2 co-mutations or RAS pathway mutations and had higher frequency of CEBPA mutations. Ery-AML was defined by complex karyotypes and TP53 mutations. A trend towards improved OS and EFS with hypomethylating agent-venetoclax combination was observed in My-AML, but not Mo-AML. These findings define distinct progression of CMML and set the basis for future studies evaluating the role of phenotype-specific therapeutics.

Keywords:  CMML; genotype; monocytic; myeloid; phenotype; transformation

DOI:  https://doi.org/10.1111/bjh.19060
Clin Cancer Res. 2023 Aug 21. pii: CCR-23-0954. [Epub ahead of print]

Improved post-transplant outcomes in recent years for AML patients with FLT3-ITD and wild-type NPM1: a report from the EBMT acute leukemia working party.

Ali Bazarbachi, Myriam Labopin, Tobias Gedde-Dahl, Peter Remenyi, Edouard Forcade, Nicolaus Kröger, Gerard Socié, Charles Craddock, Jean Henri Bourhis, Jurjen Versluis, Ibrahim Yakoub-Agha, Urpu Salmenniemi, Jean El-Cheikh, Gesine Bug, Jordi Esteve, Arnon Nagler, Fabio Ciceri, Mohamad Mohty.

PURPOSE: Allogeneic hematopoietic cell transplantation (allo-HCT) is recommended in first complete remission (CR1) in acute myeloid leukemia (AML) patients harboring FLT3 internal tandem duplication (FLT3-ITD). We assessed changes over time in transplant characteristics and outcomes in AML patients aged 60 years and younger with a FLT3 ITD.EXPERIMENTAL DESIGN: We identified 1827 adult AML patients (median age 49 years, range 18-60) with FLT3 ITD and intermediate karyotype, allografted between 2012 and 2021 in CR1.
RESULTS: NPM1 was mutated in 72% of patients. We compared changes over time in 688 patients transplanted between 2012 and 2016, and 1139 patients transplanted between 2017 and 2021. For patients with wild-type NPM1, the 2-year leukemia free survival (LFS) and overall survival (OS) significantly improved over time from 54% to 64% (hazard ratio [HR] =0.67; p=0.011) and from 63% to 71% (HR=0.66; p=0.021), respectively. Allo-HCT in recent years significantly reduced the cumulative incidence of relapse (CIR). For patients with NPM1 mutation, no significant changes over time were noted.
CONCLUSIONS: In AML patients with FLT3 ITDand wild-type NPM1, we noticed a significant decrease over time in the CIR and improvement of LFS and OS, likely reflecting the efficacy of FLT-3 inhibitors, including when used as post-transplant maintenance, in this high-risk setting. On the contrary, no significant change over time was noticed in outcomes of patients harboring a FLT3 and NPM1 mutation.

DOI: https://doi.org/10.1158/1078-0432.CCR-23-0954
Nat Genet. 2023 Aug 24.

Multiparameter prediction of myeloid neoplasia risk.

Muxin Gu, Sruthi Cheloor Kovilakam, William G Dunn, Ludovica Marando, Clea Barcena, Irina Mohorianu, Alexandra Smith, Siddhartha P Kar, Margarete A Fabre, Moritz Gerstung, Catherine A Cargo, Luca Malcovati, Pedro M Quiros, George S Vassiliou.

The myeloid neoplasms encompass acute myeloid leukemia, myelodysplastic syndromes and myeloproliferative neoplasms. Most cases arise from the shared ancestor of clonal hematopoiesis (CH). Here we analyze data from 454,340 UK Biobank participants, of whom 1,808 developed a myeloid neoplasm 0-15 years after recruitment. We describe the differences in CH mutational landscapes and hematology/biochemistry test parameters among individuals that later develop myeloid neoplasms (pre-MN) versus controls, finding that disease-specific changes are detectable years before diagnosis. By analyzing differences between 'pre-MN' and controls, we develop and validate Cox regression models quantifying the risk of progression to each myeloid neoplasm subtype. We construct 'MN-predict', a web application that generates time-dependent predictions with the input of basic blood tests and genetic data. Our study demonstrates that many individuals that develop myeloid neoplasms can be identified years in advance and provides a framework for disease-specific prognostication that will be of substantial use to researchers and physicians.

DOI: https://doi.org/10.1038/s41588-023-01472-1
Haematologica. 2023 Aug 24.

SUMOylation inhibitor TAK-981 (subasumstat) synergizes with 5-azacitidine in preclinical models of acute myeloid leukemia.

Ludovic Gabellier, Marion De Toledo, Mehuli Chakraborty, Dana Akl, Rawan Hallal, Mays Aqrouq, Giovanni Buonocore, Clara Recasens-Zorzo, Guillaume Cartron, Abigaïl Delort, Marc Piechaczyk, Denis Tempé, Guillaume Bossis.

Acute Myeloid Leukemias (AML) are severe hematomalignancies with dismal prognosis. The post-translational modification SUMOylation plays key roles in leukemogenesis and AML response to therapies. Here, we show that TAK-981 (subasumstat), a first-in-class SUMOylation inhibitor, is endowed with potent anti-leukemic activity in various preclinical models of AML. TAK-981 targets AML cell lines and patient blast cells in vitro and in vivo in xenografted mice with minimal toxicity on normal hematopoietic cells. Moreover, it synergizes with 5-azacitidine (AZA), a DNA-hypomethylating agent now used in combination with the BCL-2 inhibitor venetoclax to treat AML patients unfit for standard chemotherapies. Interestingly, TAK-981+AZA combination shows higher anti-leukemic activity than AZA+venetoclax combination both in vitro and in vivo, at least in the models tested. Mechanistically, TAK-981 potentiates the transcriptional reprogramming induced by AZA, promoting apoptosis, alteration of the cell cycle and differentiation of the leukemic cells. In addition, TAK-981+AZA treatment induces many genes linked to inflammation and immune response pathways. In particular, this leads to the secretion of type I interferon (IFN-I) by AML cells. Finally, TAK-981+AZA induces the expression of Natural Killer (NK)-activating ligands (MICA/B) and adhesion proteins (ICAM-1) at the surface of AML cells. Consistently, TAK-981+AZA-treated AML cells activate NKs and increase their cytotoxic activity. Targeting SUMOylation with TAK-981 may thus be a promising strategy to both sensitize AML cells to AZA and reduce their immune-escape capacities.

DOI: https://doi.org/10.3324/haematol.2023.282704
Leukemia. 2023 Aug 21.

Glasdegib plus intensive or non-intensive chemotherapy for untreated acute myeloid leukemia: results from the randomized, phase 3 BRIGHT AML 1019 trial.

Mikkael A Sekeres, Pau Montesinos, Jan Novak, Jianxiang Wang, Deepa Jeyakumar, Benjamin Tomlinson, Jiri Mayer, Erin Jou, Tadeusz Robak, David C Taussig, Hervé Dombret, Akil Merchant, Naveed Shaik, Thomas O'Brien, Whijae Roh, Xueli Liu, Wendy Ma, Christine G DiRienzo, Geoffrey Chan, Jorge E Cortes.

This is the primary report of the randomized, placebo-controlled phase 3 BRIGHT AML 1019 clinical trial of glasdegib in combination with intensive chemotherapy (cytarabine and daunorubicin) or non-intensive chemotherapy (azacitidine) in patients with untreated acute myeloid leukemia. Overall survival (primary endpoint) was similar between the glasdegib and placebo arms in the intensive (n = 404; hazard ratio [HR] 1.05; 95% confidence interval [CI]: 0.782-1.408; two-sided p = 0.749) and non-intensive (n = 325; HR 0.99; 95% CI: 0.768-1.289; two-sided p = 0.969) studies. The proportion of patients who experienced treatment-emergent adverse events was similar for glasdegib versus placebo (intensive: 99.0% vs. 98.5%; non-intensive: 99.4% vs. 98.8%). The most common treatment-emergent adverse events were nausea, febrile neutropenia, and anemia in the intensive study and anemia, constipation, and nausea in the non-intensive study. The addition of glasdegib to either cytarabine and daunorubicin or azacitidine did not significantly improve overall survival and the primary efficacy endpoint for the BRIGHT AML 1019 phase 3 trial was not met. Clinical trial registration: ClinicalTrials.gov: NCT03416179.

DOI: https://doi.org/10.1038/s41375-023-02001-z
Nat Commun. 2023 Aug 22. 14(1): 5092

Convergent somatic evolution commences in utero in a germline ribosomopathy.

Heather E Machado, Nina F Øbro, Nicholas Williams, Shengjiang Tan, Ahmed Z Boukerrou, Megan Davies, Miriam Belmonte, Emily Mitchell, E Joanna Baxter, Nicole Mende, Anna Clay, Philip Ancliff, Jutta Köglmeier, Sally B Killick, Austin Kulasekararaj, Stefan Meyer, Elisa Laurenti, Peter J Campbell, David G Kent, Jyoti Nangalia, Alan J Warren.

Clonal tracking of cells using somatic mutations permits exploration of clonal dynamics in human disease. Here, we perform whole genome sequencing of 323 haematopoietic colonies from 10 individuals with the inherited ribosomopathy Shwachman-Diamond syndrome to reconstruct haematopoietic phylogenies. In ~30% of colonies, we identify mutually exclusive mutations in TP53, EIF6, RPL5, RPL22, PRPF8, plus chromosome 7 and 15 aberrations that increase SBDS and EFL1 gene dosage, respectively. Target gene mutations commence in utero, resulting in a profusion of clonal expansions, with only a few haematopoietic stem cell lineages (mean 8, range 1-24) contributing ~50% of haematopoietic colonies across 8 individuals (range 4-100% clonality) by young adulthood. Rapid clonal expansion during disease transformation is associated with biallelic TP53 mutations and increased mutation burden. Our study highlights how convergent somatic mutation of the p53-dependent nucleolar surveillance pathway offsets the deleterious effects of germline ribosomopathy but increases opportunity for TP53-mutated cancer evolution.

DOI: https://doi.org/10.1038/s41467-023-40896-5
Blood. 2023 Aug 24. pii: blood.2022019580. [Epub ahead of print]

Modulation of Human Thrombopoietin Receptor Conformations Uncouples JAK2 V617F-Driven From Cytokine-Induced Activation.

Nicolas Papadopoulos, Ajda Pristavec, Audrey Nédélec, Gabriel Levy, Judith Staerk, Stefan N Constantinescu.

The Thrombopoietin Receptor (TpoR) is a central player in Myeloproliferative Neoplasms (MPNs). Mutations in JAK2, calreticulin or in TpoR itself drive constitutive activation of TpoR and uncontrolled proliferation and differentiation of hematopoietic stem cells and progenitors. The JAK2 V617F mutation is responsible for the majority of MPNs and all driver mutants induce pathologic TpoR activation. Existing therapeutic strategies have focused on JAK2 kinase inhibitors that are unable to differentiate between the mutated MPN clone and healthy cells. Surprisingly, targeting of TpoR itself has remained poorly explored despite its central role in the pathology. Here, we performed a comprehensive characterization of human TpoR activation in physiological and pathological conditions focusing on the JAK2 V617F mutant. Using a system of controlled dimerization of transmembrane and cytosolic domains of TpoR, we discovered that the human TpoR (hTpoR) adopts different dimeric conformations upon Tpo-induced versus JAK2 V617F-mediated activation. We identified the amino acids and the specific dimeric conformation of hTpoR responsible for activation in complex with JAK2 V617F and confirmed our findings in the full-length receptor context in hematopoietic cell lines and primary bone marrow cells. Remarkably, we find that modulation of hTpoR conformations by point mutations allows specific inhibition of the JAK2 V617F-driven activation without affecting Tpo-induced signaling. Our results demonstrate that modulation of hTpoR conformation is a viable therapeutic strategy for JAK2 V617F positive MPNs and set the path for novel drug development by identifying precise residues of hTpoR involved in JAK2 V617F specific activation.

DOI: https://doi.org/10.1182/blood.2022019580
J Clin Oncol. 2023 Aug 22. JCO2300866

Allogeneic Hematopoietic Cell Transplantation Improves Outcome in Myelodysplastic Syndrome Across High-Risk Genetic Subgroups: Genetic Analysis of the Blood and Marrow Transplant Clinical Trials Network 1102 Study.

Blood and Marrow Transplant Clinical Trials Network

PURPOSE: Allogeneic hematopoietic cell transplantation (HCT) in patients with myelodysplastic syndrome (MDS) improves overall survival (OS). We evaluated the impact of MDS genetics on the benefit of HCT in a biological assignment (donor v no donor) study.METHODS: We performed targeted sequencing in 309 patients age 50-75 years with International Prognostic Scoring System (IPSS) intermediate-2 or high-risk MDS, enrolled in the Blood and Marrow Transplant Clinical Trials Network 1102 study and assessed the association of gene mutations with OS. Patients with TP53 mutations were classified as TP53multihit if two alleles were altered (via point mutation, deletion, or copy-neutral loss of heterozygosity).
RESULTS: The distribution of gene mutations was similar in the donor and no donor arms, with TP53 (28% v 29%; P = .89), ASXL1 (23% v 29%; P = .37), and SRSF2 (16% v 16%; P = .99) being most common. OS in patients with a TP53 mutation was worse compared with patients without TP53 mutation (21% ± 5% [SE] v 52% ± 4% at 3 years; P < .001). Among those with a TP53 mutation, OS was similar between TP53single versus TP53multihit (22% ± 8% v 20% ± 6% at 3 years; P = .31). Considering HCT as a time-dependent covariate, patients with a TP53 mutation who underwent HCT had improved OS compared with non-HCT treatment (OS at 3 years: 23% ± 7% v 11% ± 7%; P = .04), associated with a hazard ratio of 3.89; 95% CI, 1.87 to 8.12; P < .001 after adjustment for covariates. OS among patients with molecular IPSS (IPSS-M) very high risk without a TP53 mutation was significantly improved if they had a donor (68% ± 10% v 0% ± 12% at 3 years; P = .001).
CONCLUSION: HCT improved OS compared with non-HCT treatment in patients with TP53 mutations irrespective of TP53 allelic status. Patients with IPSS-M very high risk without a TP53 mutation had favorable outcomes when a donor was available.

DOI: https://doi.org/10.1200/JCO.23.00866
Exp Hematol. 2023 Aug 21. pii: S0301-472X(23)01673-9. [Epub ahead of print]

Complementary and countervailing actions of Jak2 and Ikk2 in hematopoiesis in mice.

Daniel A C Fisher, Angelo B A Laranjeira, Tim Kong, Steven C Snyder, Kevin Shim, Mary C Fulbright, Stephen T Oh.

  Hyperactivation of JAK2 kinase is a unifying feature of human Ph- myeloproliferative neoplasms (MPNs), most commonly due to the JAK2 V617F mutation. Mice harboring a homologous mutation in the Jak2 locus exhibit a phenotype resembling polycythemia vera. NFκB pathway hyperactivation is present in myeloid neoplasms, including MPNs, despite scarcity of mutations in NFκB pathway genes. To determine the impact of NFκB pathway hyperactivation in conjunction with Jak2 V617F, we utilized Ikk2 (Ikk2-CA) mice. Pan-hematopoietic Ikk2-CA alone produced depletion of hematopoietic stem cells and B cells. When combined with the Jak2 V617F mutation, Ikk2-CA rescued the polycythemia vera phenotype of Jak2 V617F. Likewise, Jak2 V617F ameliorated defects in hematopoiesis produced by Ikk2-CA. Single cell RNA sequencing of hematopoietic stem and progenitor cells revealed multiple genes antagonistically regulated by Jak2 and Ikk2, including subsets whose expression was altered by Jak2 V617F and/or Ikk2-CA, but partly or fully rectified in the double mutant. We hypothesize that Jak2 promotes hematopoietic stem cell (HSC) population self-renewal, while Ikk2 promotes myeloid lineage differentiation, and biases cell fates at several branch points in hematopoiesis. Jak2 and Ikk2 both regulate multiple genes affecting myeloid maturation and cell death. Therefore, the presence of dual Jak2 and NFκB hyperactivation may present neomorphic therapeutic vulnerabilities in myeloid neoplasms.

Keywords:  Hematopoiesis; Jak-Stat signaling; Mass cytometry; Myeloid progenitor; NF kappa B signaling; Single cell RNA sequencing; hematopoietic stem cell; myeloproliferative neoplasms

DOI:  https://doi.org/10.1016/j.exphem.2023.08.005
Hemasphere. 2023 Sep;7(9): e947

Genetic Predisposition to Clonal Hematopoiesis.

Pedro M Quiros, George S Vassiliou.

DOI: https://doi.org/10.1097/HS9.0000000000000947
Biochem Pharmacol. 2023 Aug 19. pii: S0006-2952(23)00350-7. [Epub ahead of print] 115759

Acquired Resistance to Venetoclax plus Azacitidine in Acute Myeloid Leukemia: in vitro Models and Mechanisms.

Jenna L Carter, Yongwei Su, Xinan Qiao, Jianlei Zhao, Guan Wang, Mackenzie Howard, Holly Edwards, Xun Bao, Jing Li, Maik Hüttemann, Jay Yang, Jeffrey W Taub, Yubin Ge.

  The combination of venetoclax (VEN) and azacitidine (AZA) has become the standard of care for acute myeloid leukemia (AML) patients who are ≥75 years or unfit for intensive chemotherapy. Though initially promising, resistance to the combination therapy is an issue and VEN+AZA-relapsed/refractory patients have dismal outcomes. To better understand the mechanisms of resistance, we developed VEN+AZA-resistant AML cell lines, MV4-11/VEN+AZA-R and ML-2/VEN+AZA-R, which show >300-fold persistent resistance compared to the parental lines. We demonstrate that these cells have unique metabolic profiles, including significantly increased levels of cytidine triphosphate (CTP) and deoxycytidine triphosphate (dCTP), changes in fatty acid and amino acid metabolism and increased utilization and reliance on glycolysis. Furthermore, fatty acid transporter CD36 is increased in the resistant cells compared to the parental cells. Inhibition of glycolysis with 2-Deoxy-D-glucose re-sensitized the resistant cells to VEN+AZA. In addition, the VEN+AZA-R cells have increased levels of the antiapoptotic protein Mcl-1 and decreased levels of the pro-apoptotic protein Bax. Overexpression of Mcl-1 or knockdown of Bax result in resistance to VEN+AZA. Our results provide insight into the molecular mechanisms contributing to VEN+AZA resistance and assist in the development of novel therapeutics to overcome this resistance in AML patients.

Keywords:  Acute myeloid leukemia; Bax; Mcl-1; glycolysis; pyrimidine metabolism; venetoclax+azacitidine-resistance

DOI:  https://doi.org/10.1016/j.bcp.2023.115759
Blood Adv. 2023 Aug 22. 7(16): 4660-4670

Cell-free DNA measurable residual disease as a predictor of postallogeneic hematopoietic cell transplant outcomes.

Sergiu Pasca, Matthew Z Guo, Shiyu Wang, Kristin Stokvis, Audra Shedeck, Aparna Pallavajjala, Cynthia Shams, Roshni Pallavajjala, Amy E DeZern, Ravi Varadhan, Christopher D Gocke, Richard J Jones, Lukasz P Gondek.

The measurable residual disease (MRD) assessment provides an attractive predictor of allogeneic hematopoietic cell transplnat (alloHCT) outcomes. Cell-free DNA (cfDNA) has been applied to diagnosis, early detection, and disease burden monitoring in various tumors, but its utility as an MRD test in myeloid malignancies has not been systematically evaluated. We sought to determine the differential sensitivity between bone marrow (BM) and cfDNA MRD and to assess the effect of cfDNA MRD on alloHCT outcomes. The technical and clinical validation cohorts, including 82 patients participating in clinical trials (Bone Marrow Transplant Clinical Trials Network-0201 and 0402), were used. Ultradeep error-corrected targeted sequencing was performed on plasma and BM-derived DNA. We demonstrated that 94.6% (range, 93.9-95.3) of cfDNA was derived from hematopoietic tissue. The mutant allele fraction was congruent between BM and cfDNA (rho = 0.8; P < .0001); however, cfDNA seemed to be more sensitive in detecting clones with a variant allele frequency (VAF) of <0.26%. cfDNA-MRD clearance by day 90 after alloHCT (D90) was associated with improved relapse-free survival (RFS, median survival not reached vs 5.5 months; P < .0001) and overall survival (OS, median survival not reached vs 7.3 months; P < .0001) when compared with patients with persistent MRD. Irrespective of pre-alloHCT MRD, D90 cfDNA MRD was associated with inferior 2-year OS (16.7% vs 84.8%; P < .0001) and RFS (16.7% vs 80.7%; P < .0001). cfDNA seems to be an accurate, minimally invasive alternative to BM aspirates in MRD assessment and confers important prognostic implications in patients with myeloid malignancies undergoing alloHCT.

DOI: https://doi.org/10.1182/bloodadvances.2023010416
Clin Epigenetics. 2023 Aug 24. 15(1): 134

Cell-free DNA 5-hydroxymethylcytosine is highly sensitive for MRD assessment in acute myeloid leukemia.

Jianming Shao, Shilpan Shah, Siddhartha Ganguly, Youli Zu, Chuan He, Zejuan Li.

  Measurable residual disease (MRD) is an important biomarker in acute myeloid leukemia (AML). However, MRD cannot be detected in many patients using current methods. We developed a highly sensitive 5-hydroxymethylcytosine (5hmC) signature in cell-free DNA by analyzing 115 AML patients and 86 controls. The 5hmC method detected MRD in 20 of 29 patients with negative MRD by multiparameter flow cytometry and 11 of 14 patients with negative MRD by molecular methods. MRD detection by the 5hmC method was significantly associated with relapse-free survival. This novel method can be used in most AML patients and may significantly impact AML patient management.

Keywords:  5-hydroxymethylcytosine; Acute myeloid leukemia; Cell-free DNA; Measurable residual disease

DOI:  https://doi.org/10.1186/s13148-023-01547-0
Leuk Res. 2023 Aug 04. pii: S0145-2126(23)00633-1. [Epub ahead of print]133 107368

Safety and efficacy of FLAG-Ida-based therapy combined with venetoclax for the treatment for newly diagnosed and relapsed/refractory patients with AML - A systematic review.

A Sherban, D Fredman, S Shimony, M Yeshurun, P Raanani, M Stahi, A Gafter-Gvili, O Wolach.

  Venetoclax (VEN) in combination with intensive chemotherapy (IC) is increasingly used to treat patients with high-risk acute myeloid leukemia (AML). We conducted a systematic review to assess the safety and efficacy outcomes of FLAG-IDA in combination with VEN. The primary safety outcome was infection rate; the primary efficacy outcome was response to treatment (composite complete remission (CRc) and overall response rate (ORR). Risk of bias was assessed according to the ROBINS-I tool. Six studies including 221 patients with newly-diagnosed (ND AML (n = 120)) and R/R AML (n = 101) disease, were included in this systematic review. Pooling of results was not conducted due to major differences between studies. The reported rates of neutropenic fever, bacteremia, pneumonia and invasive fungal infections were at 44-55 %, 24-48 %, 12-30 % and 11-36 % of assessed patients, respectively. Time to ANC and platelet recovery ranged between 23 and 29 and 23-31 days, respectively. Early death rate was 8.7 % (14/160) patients: four patients at 30 days, additional ten in 60 days. CRc rates ranged between 53 % and 78 % for R/R AML. CRc for ND was reported by one study only (89 %). ORR were reported in 60-78 % of patients with R/R AML. Only one study reported an ORR for ND patients of 98 %. In our systematic review, FLAG-Ida plus VEN proved to be a potentially tolerable and effective regimen in ND and R/R AML patients. We suggest further evaluation and confirmation for the safety and efficacy of this new protocol in future RCTs.

Keywords:  AML; Flag-Ida; Venetoclax

DOI:  https://doi.org/10.1016/j.leukres.2023.107368
EJHaem. 2023 Aug;4(3): 723-727

Serum D-2-hydroxyglutarate and the ratio of D-2HG/L-2HG predict IDH mutation in acute myeloid leukemia.

Chelsea Zhang, Andrew Chu, Richard Boriack, Robert Collins, Jing Xu, Dwight Oliver, Ruifang Zheng, Dinesh Rakheja, Weina Chen.

  This study investigates whether serum D-2HG (D-2-hydroxyglutarate) produced by the mutated isocitrate dehydrogenase (IDH) can predict IDH mutations in acute myeloid leukemia (AML) at diagnosis. D-2HG and L-2HG are measured by liquid chromatography-tandem mass spectrometry. D-2HG, total 2HG and the D/L ratio (D-2HG/L-2HG) are significantly higher in IDH mutated cases than in IDH wild cases. The optimal cutoff values to predict IDH mutations at 100% sensitivity (specificity 91%-94%) are >588 ng/mL for D-2HG and >2.33 for the D/L ratio. Our study indicates that elevated serum D-2HG and the D/L ratio may serve as noninvasive biomarkers of IDH mutation in AML.

Keywords:  D‐2HG/L‐2HG Ratio; D‐2‐Hydroxyglutarate; IDH; L‐2‐Hydroxyglutarate; acute myeloid leukemia

DOI:  https://doi.org/10.1002/jha2.723
J Chemother. 2023 Aug 20. 1-6

Comparison of venetoclax and ivosidenib/enasidenib for unfit newly diagnosed patients with acute myeloid leukemia and IDH1/2 mutation: a network meta-analysis.

Lida Wang, Jiwu Song, Xiangming Xiao, Dianfang Li, Tianmeng Liu, Xiaopo He.

  Because of lacking of head-to-head comparison between venetoclax and IDH1/IDH2 inhibitors (ivosidenib/enasidenib) for newly diagnosed unfit patients with acute myeloid leukemia (AML), the optimal option for these patients still remains undefined. We searched relevant published reports. Three RCTs with 180 IDH1 mutant and 165 IDH2 mutant patients were identified. Indirect comparison of OS using fixed effects network meta-analysis (NMA) models indicated venetoclax plus azacitidine (Ven-Aza) significantly improved survival than enasidenib plus azacitidine (Ena-Aza) (HR:0.30, p = 0.005) for those newly diagnosed patients with AML and IDH2 Mutation. And, for those IDH2 mutation patients, Ven-Aza also had the highest probability of 98.3% (OS analysis) and 84.0% (CR/CRi analysis) to be the best intervention among these first-line treatment regimens (Ven-Aza, Ena-Aza and Aza). And, there was a favorable trend towards Ven-Aza in survival analysis (HR:0.69, p = 0.42), when compared to ivosidenib plus azacitidine (Ivo-Aza) for those newly diagnosed patients with AML and IDH1 Mutation. For those IDH1 Mutation, venetoclax plus azacitidine (Ven-Aza) had the highest probability of 65.8% (OS analysis) and 73.0% (CR/CRi analysis) to be the best intervention among these first-line treatment regimens (Ven-Aza, ivosidenib plus azacitidine (Ivo-Aza) and azacitidine (Aza)). In conclusion, venetoclax plus azacitidine could be a good option for unfit newly diagnosed patients with acute myeloid leukemia and IDH1/2 mutation. Considering our limits (only trial data-based network meta-analysis et al.), future trials directly comparing these regimens are warranted.

Keywords:  Acute myeloid leukemia; IDH2 mutation; enasidenib; ivosidenib; newly diagnosed; venetoclax

DOI:  https://doi.org/10.1080/1120009X.2023.2247200
Front Oncol. 2023 ;13 1204895

Therapeutic targeting of leukemia stem cells in acute myeloid leukemia.

Karina Barbosa, Aniruddha J Deshpande.

  One of the distinguishing properties of hematopoietic stem cells is their ability to self-renew. Since self-renewal is important for the continuous replenishment of the hematopoietic stem cell pool, this property is often hijacked in blood cancers. Acute myeloid leukemia (AML) is believed to be arranged in a hierarchy, with self-renewing leukemia stem cells (LSCs) giving rise to the bulk tumor. Some of the earliest characterizations of LSCs were made in seminal studies that assessed the ability of prospectively isolated candidate AML stem cells to repopulate the entire heterogeneity of the tumor in mice. Further studies indicated that LSCs may be responsible for chemotherapy resistance and therefore act as a reservoir for secondary disease and leukemia relapse. In recent years, a number of studies have helped illuminate the complexity of clonality in bone marrow pathologies, including leukemias. Many features distinguishing LSCs from normal hematopoietic stem cells have been identified, and these studies have opened up diverse avenues for targeting LSCs, with an impact on the clinical management of AML patients. This review will discuss the role of self-renewal in AML and its implications, distinguishing characteristics between normal and leukemia stem cells, and opportunities for therapeutic targeting of AML LSCs.

Keywords:  acute myeloid leukemia; cancer stem cells; leukemia stem cells (LSCs); malignant hematopoiesis; self-renewal and differentiation

DOI:  https://doi.org/10.3389/fonc.2023.1204895
Br J Haematol. 2023 Aug 25.

Prognostic impact of FLT3-ITD mutation on NPM1+ acute myeloid leukaemia patients and related molecular mechanisms.

Xin'an Pan, Yingjun Chang, Guorui Ruan, Fangfang Wei, Hao Jiang, Qian Jiang, Xiaojun Huang, Xiaosu Zhao.

  The prognosis of acute myeloid leukaemia (AML) patients carrying NPM1 mutations is significantly worse when accompanied by FLT3-ITD mutations. However, accurate quantitative detection of FLT3-ITD mutations remains challenging. To identify a novel biomarker in NPM1+ FLT3-ITD+ AML patients for more accurate stratification, we analysed the differential gene expression between the NPM1+ FLT3-ITD+ and NPM1+ FLT3-ITD- groups in five public AML datasets and identified a biomarker by taking the intersection of differentially expressed genes. We validated this biomarker in bone marrow samples from NPM1+ AML patients at the Peking University Institute of Haematology and analysed its prognostic significance. BCAT1 expression was higher in the NPM1+ FLT3-ITD+ group than in the NPM1+ FLT3-ITD- group in all seven cohorts. BCAT1 was able to predict the prognosis of NPM1+ FLT3-ITD+ AML patients, and its predictive ability was superior to that of the FLT3-ITD allelic ratio (AR). FLT3-targeted inhibitor quizartinib reduced BCAT1 expression. BCAT1 knockdown using lentiviral vectors led to the downregulation of MYC expression. Thus, we identified BCAT1 as a novel biomarker for NPM1+ FLT3-ITD+ AML patients. The FLT3-ITD/BCAT1/MYC signalling pathway may play a biological role in promoting the occurrence and development of AML in FLT3-ITD+ cell lines.

Keywords:   BCAT1 ; FLT3-ITD mutation; NPM1 mutation; acute myeloid leukaemia

DOI:  https://doi.org/10.1111/bjh.18973
Cancers (Basel). 2023 Aug 18. pii: 4161. [Epub ahead of print]15(16):

A Multicenter Retrospective Chart Review Study of Treatment and Disease Patterns and Clinical Outcomes of Patients with Chronic-Phase Chronic Myeloid Leukemia in Third-Line Treatment or with T315I Mutation.

Franck-Emmanuel Nicolini, Françoise Huguet, Lynn Huynh, Churong Xu, Christophe Bouvier, Aurore Yocolly, Gabriel Etienne.

  This retrospective chart review study investigated the clinical burden of adult patients with chronic-phase chronic myeloid leukemia (CP-CML) treated at three centers in France (2006-2021) who failed on two or more tyrosine kinase inhibitors (TKIs; third-line [3L]+ cohort) or harbored the BCR::ABL1 T315I mutation (T315I cohort). In the 3L+ cohort (N = 157; median age at diagnosis, 56 years), TKIs received in 3L (median duration: 17 months) were dasatinib (32%), nilotinib (19%), imatinib (18%), ponatinib (17%), and bosutinib (14%). Of the 145 patients with documented responses in 3L, 42% experienced major molecular response (MMR) at 12 months. Median event-free survival [95% confidence interval] was 53.6 [44.0, 67.5] months, and median progression-free survival and overall survival (OS) were not reached. Achieving MMR in 3L was associated with a decreased mortality risk. In the T315I cohort (N = 17; 52 years), 41% of patients received five or more lines of therapy. Following identification of the T315I mutation, ponatinib was the most common TKI used (59%); the median [interquartile range] OS was 5 [3-10] years. The most common adverse events were infections (3L+ cohort) and thrombocytopenia (T315I cohort) (both 18%). Well-tolerated therapies that achieve durable responses are needed in 3L or earlier to improve CP-CML prognosis.

Keywords:  T315I mutation; chronic-phase chronic myeloid leukemia (CML-CP); overall survival; treatment patterns; tyrosine kinase inhibitor (TKI)

DOI:  https://doi.org/10.3390/cancers15164161
EJHaem. 2023 Aug;4(3): 760-764

Presence but not number of secondary type mutations influences outcome in de novo AML without MDS-associated or recurring cytogenetic abnormalities.

Olga K Weinberg, Miguel D Cantu, Jeffrey Gagan, Yazan F Madanat, Daniel A Arber, Robert P Hasserjian.

  A group of gene mutations has been identified to be strongly associated with secondary acute myeloid leukemias (AML) arising from prior myeloid neoplasms. The International Consensus Classification (ICC) and proposed 5th edition of the World Health Organization (WHO) classification differ by inclusion of RUNX1. A recent study suggested that having two or more secondary mutations is associated with a particularly poor prognosis. In a study of 294 de novo AML patients, we found that patients with at least one ICC-defined secondary mutation had shorter survival when compared to those without secondary mutations, and ICC/WHO groups of two or more mutations did not predict for worse outcomes.

Keywords:  AML; GENETICS; MUTATIONS

DOI:  https://doi.org/10.1002/jha2.710
ACS Chem Biol. 2023 Aug 21.

Base Editor Scanning Reveals Activating Mutations of DNMT3A.

Emma M Garcia, Nicholas Z Lue, Jessica K Liang, Whitney K Lieberman, Derek D Hwang, James C Woods, Brian B Liau.

DNA methyltransferase 3A (DNMT3A) is a de novo cytosine methyltransferase responsible for establishing proper DNA methylation during mammalian development. Loss-of-function (LOF) mutations to DNMT3A, including the hotspot mutation R882H, frequently occur in developmental growth disorders and hematological diseases, including clonal hematopoiesis and acute myeloid leukemia. Accordingly, identifying mechanisms that activate DNMT3A is of both fundamental and therapeutic interest. Here, we applied a base editor mutational scanning strategy with an improved DNA methylation reporter to systematically identify DNMT3A activating mutations in cells. By integrating an optimized cellular recruitment strategy with paired isogenic cell lines with or without the LOF hotspot R882H mutation, we identify and validate three distinct hyperactivating mutations within or interacting with the regulatory ADD domain of DNMT3A, nominating these regions as potential functional target sites for pharmacological intervention. Notably, these mutations are still activating in the context of a heterozygous R882H mutation. Altogether, we showcase the utility of base editor scanning for discovering functional regions of target proteins.

DOI: https://doi.org/10.1021/acschembio.3c00257
Blood Adv. 2023 Aug 23. pii: bloodadvances.2023010850. [Epub ahead of print]

Myeloablative Fractionated Busulfan for Allogeneic Stem Cell Transplant in Older Patients or Patients with Comorbidities.

Uday R Popat, Oren Pasvolsky, Roland Bassett, Rohtesh S Mehta, Amanda L Olson, Julianne Chen, Amin Majid Alousi, Gheath Al-Atrash, Qaiser Bashir, Alison M Gulbis, Chitra M Hosing, Jin S Im, Partow Kebriaei, Issa F Khouri, David C Marin, Yago Nieto, Betul Oran, Neeraj Y Saini, Terri Lynn Shigle, Samer A Srour, Jeremy Leon Ramdial, Katayoun Rezvani, Muzaffar H Qazilbash, Borje S Andersson, Richard E Champlin, Elizabeth J Shpall.

Traditional conditioning regimens for patients undergoing allogeneic hematopoietic stem cell transplantation (alloHCT) provide suboptimal outcomes, especially for older patients and those with comorbidities. We hypothesized that a fractionated myeloablative busulfan dose delivered over an extended period would reduce non-relapse mortality (NRM), while retaining anti-leukemic effects. Here, we performed a phase II trial for adults with hematological malignancies receiving matched related or unrelated alloHCT. Participants received busulfan 80mg/m2 outpatient on days -20 and -13 before transplant. Fludarabine 40mg/m2 was given on days -6 to -2 followed by busulfan dosed to achieve a target area under the curve of 20,000mol/min for the whole course. The primary endpoint was day 100 NRM. Seventy-eight patients were included, with a median age of 61 (range 39-70) years, transplanted for acute leukemia (24%), MDS (27%), or MPD/CML (44%). HCT specific comorbidity index (HCT-CI) was >3 in 34 (44%). With a median follow-up of 36.4 (range 2.9-51.5) months, 100-day, 1-year and 3-year NRM was 3.8% (95%CI, 0-8.1%), 8% (95%CI, 2-14%), and 9.3% (95%CI, 2.6-15.9%), without a significant difference by age or HCT-CI score. One-year and 3-year relapse incidence was 10% (95%CI, 4-17%) and 18% (95%CI, 9-27%), respectively. Three-year overall survival was 80% (95%CI, 72-90%) and was similar for patients >60 and <60 years of age, as well as those with HCT-CI>3 and HCT-CI<3. Overall, we found that a myeloablative fractionated busulfan regimen has low NRM without an increase in relapse rate, resulting in promising survival, even in older patients or in patients with comorbidities.

DOI: https://doi.org/10.1182/bloodadvances.2023010850
EJHaem. 2023 Aug;4(3): 867-868

An ETV6::NTRK3 fusion transcript in a core-binding factor acute myeloid leukemia.

Lucie Coster, Françoise Huguet, Alban Canali, Jean-Baptiste Rieu, Véronique Mansat- De Mas.



Keywords:  acute myeloid leukemia; core‐binding factor leukemia; fusion transcript; translocation; tyrosine kinase inhibitor

DOI:  https://doi.org/10.1002/jha2.706
J Exp Med. 2023 11 06. pii: e20230011. [Epub ahead of print]220(11):

Hematopoietic-specific heterozygous loss of Dnmt3a exacerbates colitis-associated colon cancer.

Yang Feng, Qingchen Yuan, Rachel C Newsome, Troy Robinson, Robert L Bowman, Ashley N Zuniga, Kendra N Hall, Cassandra M Bernsten, Daniil E Shabashvili, Kathryn I Krajcik, Chamara Gunaratne, Zachary J Zaroogian, Kartika Venugopal, Heidi L Casellas Roman, Ross L Levine, Walid K Chatila, Rona Yaeger, Alberto Riva, Christian Jobin, Daniel Kopinke, Dorina Avram, Olga A Guryanova.

Clonal hematopoiesis (CH) is defined as clonal expansion of mutant hematopoietic stem cells absent diagnosis of a hematologic malignancy. Presence of CH in solid tumor patients, including colon cancer, correlates with shorter survival. We hypothesized that bone marrow-derived cells with heterozygous loss-of-function mutations of DNMT3A, the most common genetic alteration in CH, contribute to the pathogenesis of colon cancer. In a mouse model that combines colitis-associated colon cancer (CAC) with experimental CH driven by Dnmt3a+/Δ, we found higher tumor penetrance and increased tumor burden compared with controls. Histopathological analysis revealed accentuated colonic epithelium injury, dysplasia, and adenocarcinoma formation. Transcriptome profiling of colon tumors identified enrichment of gene signatures associated with carcinogenesis, including angiogenesis. Treatment with the angiogenesis inhibitor axitinib eliminated the colon tumor-promoting effect of experimental CH driven by Dnmt3a haploinsufficiency and rebalanced hematopoiesis. This study provides conceptually novel insights into non-tumor-cell-autonomous effects of hematopoietic alterations on colon carcinogenesis and identifies potential therapeutic strategies.

DOI: https://doi.org/10.1084/jem.20230011
Cancer Discov. 2023 Aug 25. pii: CD-23-0396. [Epub ahead of print]

STX-478, a Mutant-Selective, Allosteric PI3Ka Inhibitor Spares Metabolic Dysfunction and Improves Therapeutic Response in PI3Ka-Mutant Xenografts.

Leonard Buckbinder, David J St Jean, Trang Tieu, Brendon Ladd, Brendan Hilbert, Weixue Wang, Jacob T Alltucker, Samantha Manimala, Gregory V Kryukov, Natasja Brooijmans, Gregory Dowdell, Philip Jonsson, Michael Huff, Angel Guzman-Perez, Erica L Jackson, Marcus D Goncalves, Darrin D Stuart.

Phosphoinositide 3-kinase a (PI3Ka) is one of the most mutated genes across cancers, especially breast, gynecological, and head and neck squamous cell carcinoma tumors. Mutations occur throughout the gene, but hotspot mutations in the helical and kinase domains predominate. The therapeutic benefit of isoform-selective PI3Ka inhibition was established with alpelisib, which displays equipotent activity against the wild-type and mutant enzyme. Inhibition of wild-type PI3Ka is associated with severe hyperglycemia and rash that limits alpelisib use and suggests that selectively targeting mutant PI3Ka could reduce toxicity and improve efficacy. Here we describe STX-478, an allosteric PI3Ka inhibitor that selectively targets prevalent PI3Ka helical- and kinase-domain mutant tumors. STX-478 demonstrated robust efficacy in human tumor xenografts without causing the metabolic dysfunction observed with alpelisib. Combining STX-478 with fulvestrant and/or cyclin-dependent kinase 4/6 inhibitors was well tolerated and provided robust and durable tumor regression in ER+HER2- xenograft tumor models.

DOI: https://doi.org/10.1158/2159-8290.CD-23-0396
Int J Lab Hematol. 2023 Aug 24.

Mutations in the bZip region of the CEBPA gene: A novel prognostic factor in patients with acute myeloid leukemia.

Juan Carlos Rivera, Daniel Nuñez, Elizabet Millar, Kimberly Ramirez, Mauricio Chandía, Claudio Aguayo.

  BACKGROUND: Hematopoiesis, the process of blood cell formation involves on a complex network of transcription factors. Among them, the CCAAT-enhancer-binding protein alpha (CEBPA) plays a crucial role in maintaining the balance between myeloid proliferation and differentiation. Imbalances in this network can lead to disrupted differentiation and contribute to the development of malignant diseases.AIM: Understanding of disease development and explore potential therapeutic strategies for hematological disorders associated CEPBA gen.
MATERIALS AND METHODS: The research involved a comprehensive analysis of CEBPA gene mutations in the context of acute myeloid leukemia (AML). This encompassed a thorough exploration of point mutations and double mutations in AML patients.
RESULTS: In the context of acute myeloid leukemia (AML), mutations in the CEBPA gene, especially point mutations, are frequently observed. A significant number of AML patients present with double mutations in CEBPA, which have been linked to a more favorable prognosis in terms of overall survival and event-free survival. These patients also tend to exhibit enhanced responsiveness to treatment.
DISCUSSION: Unraveling the intricate interplay of transcription factors, particularly CEBPA, holds significant implications for decoding the mechanisms governing hematopoiesis. This understanding offers a potential avenue for deciphering disease development and devising novel therapeutic strategies for hematological disorders.
CONCLUSION: The findings underscore that CEBPA mutations correlate with enhanced overall survival and event-free survival, with relevance to those presenting within the bZip framework. This knowledge may contribute to advancing personalized treatments for hematological conditions.

Keywords:  AML; CEBPA gene; point mutations

DOI:  https://doi.org/10.1111/ijlh.14157
Curr Opin Oncol. 2023 Jun 29.

Recent advances in precision medicine for acute myeloid leukemia.

Alberto Hernández-Sánchez, Lars Bullinger.

PURPOSE OF REVIEW: Acute myeloid leukemia (AML) is a heterogeneous disease, in which treatment response and patient survival are highly conditioned by the leukemia biology. The aim of this review is to summarize recent advances in AML classification, risk stratification models, measurable residual disease (MRD) and the increasing number of treatment options that are paving the way towards precision medicine in AML.RECENT FINDINGS: AML classification and risk stratification were recently updated by incorporating novel molecular markers that are important for diagnosis and outcome prediction. In addition, the impact of co-mutational patterns is under investigation and novel approaches using machine learning algorithms are starting to be used for individualized risk estimation. Molecular markers are also becoming useful in predicting response to non-intensive treatments. MRD informs of treatment response with high sensitivity, allowing dynamic patient risk assessment and early intervention. Finally, important advances were made in AML therapy, with an increasing number of targeted therapies becoming available and many novel treatment approaches being under development with promising early results.
SUMMARY: A better understanding of AML biology is leading to improved risk stratification and important advances in treatments, which are allowing the development of precision medicine in AML at an unprecedented pace.

DOI: https://doi.org/10.1097/CCO.0000000000000965
EJHaem. 2023 Aug;4(3): 876-881

Next-generation sequencing of baseline genetic mutations and outcomes of eltrombopag and azacitidine therapy in patients with myelodysplastic syndromes and thrombocytopenia: Data from the SUPPORT clinical trial.

Pedro Marques Ramos, Jeea Choi, Catarina D Campbell, Ying A Wang, Celine Pallaud, Michael Dickinson, Amit Verma, Moshe Mittelman, Uwe Platzbecker, Honar Cherif, Pierre Fenaux.

  Eltrombopag has been previously shown to be effective in reversing azacitidine-mediated thrombocytopenia. This was further investigated in the SUPPORT trial, a phase III study assessing the efficacy/safety of eltrombopag plus azacitidine in patients with intermediate- to high-risk myelodysplastic syndromes and thrombocytopenia. The results did not support a clinical benefit for the addition of eltrombopag to azacitidine. We investigated if the somatic mutational profiles in the patient cohort were associated with treatment outcomes. Based on the available data, we observed no imbalance in the mutational profiles between treatment arms or a clear association between identified somatic mutations and clinical outcomes.

Keywords:  NGS; azacitidine; myelodysplastic syndromes; thrombocytopenia; thrombopoietin receptor agonist

DOI:  https://doi.org/10.1002/jha2.694
Blood Adv. 2023 Aug 23. pii: bloodadvances.2023009946. [Epub ahead of print]

Dissecting the role of SWI/SNF component ARID1B in steady state hematopoiesis.

Vikas Madan, Pavithra Shyamsunder, Pushkar Dakle, Weoi Woon Teoh, Lin Han, Zeya Cao, Hazimah Mohd Nordin, Shi Jizhong, Yu Shuizhou, Md Zakir Hossain, H Phillip Koeffler.

The ATP-dependent chromatin remodeling complex, SWI/SNF, has been implicated in normal hematopoiesis. The AT-Rich Interaction Domain 1B (ARID1B) and its paralog, ARID1A, are mutually exclusive, the DNA-interacting subunits of the BAF subclass of SWI/SNF complex. While the role of several SWI/SNF components in hematopoietic differentiation and stem cell maintenance has been reported, function of ARID1B in hematopoietic development has not been defined. To this end, we generated a mouse model of Arid1b-deficiency specifically in the hematopoietic compartment. Unlike the extensive phenotype observed in mice deficient in its paralog, ARID1A, Arid1b knockout mice exhibited a modest effect on steady-state hematopoiesis. Nonetheless, transplantation experiments showed that the reconstitution of myeloid cells in irradiated recipient mice was dependent on ARID1B. Further, to assess the effect of the complete loss of ARID1 proteins in the BAF complex, we generated mice lacking both ARID1A and ARID1B in the hematopoietic compartment. The double KO mice succumbed to acute bone marrow failure resulting from complete loss of BAF-mediated chromatin remodeling activity. Our ATAC-seq analyses revealed that >80% of loci regulated by ARID1B were distinct from those regulated by ARID1A; and ARID1B controlled expression of genes crucial in myelopoiesis. Overall, loss of ARID1B impacted chromatin dynamics in murine hematopoietic stem/progenitor cells, albeit to a lesser extent than cells lacking ARID1A.

DOI: https://doi.org/10.1182/bloodadvances.2023009946
Cell Metab. 2023 Aug 15. pii: S1550-4131(23)00272-3. [Epub ahead of print]

Comprehensive isotopomer analysis of glutamate and aspartate in small tissue samples.

Feng Cai, Divya Bezwada, Ling Cai, Rohit Mahar, Zheng Wu, Mario C Chang, Panayotis Pachnis, Chendong Yang, Sherwin Kelekar, Wen Gu, Bailey Brooks, Bookyung Ko, Hieu S Vu, Thomas P Mathews, Lauren G Zacharias, Misty Martin-Sandoval, Duyen Do, K Celeste Oaxaca, Eunsook S Jin, Vitaly Margulis, Craig R Malloy, Matthew E Merritt, Ralph J DeBerardinis.

  Stable isotopes are powerful tools to assess metabolism. 13C labeling is detected using nuclear magnetic resonance (NMR) spectroscopy or mass spectrometry (MS). MS has excellent sensitivity but generally cannot discriminate among different 13C positions (isotopomers), whereas NMR is less sensitive but reports some isotopomers. Here, we develop an MS method that reports all 16 aspartate and 32 glutamate isotopomers while requiring less than 1% of the sample used for NMR. This method discriminates between pathways that result in the same number of 13C labels in aspartate and glutamate, providing enhanced specificity over conventional MS. We demonstrate regional metabolic heterogeneity within human tumors, document the impact of fumarate hydratase (FH) deficiency in human renal cancers, and investigate the contributions of tricarboxylic acid (TCA) cycle turnover and CO2 recycling to isotope labeling in vivo. This method can accompany NMR or standard MS to provide outstanding sensitivity in isotope-labeling experiments, particularly in vivo.

Keywords:  aspartate; cancer; glutamate; isotopomer; mass spectrometry; nuclear magnetic resonance; pyruvate carboxylase; stable isotope; tricarboxylic acid cycle

DOI:  https://doi.org/10.1016/j.cmet.2023.07.013
Leukemia. 2023 Aug 25.

How should we interpret conclusions of TKI-stopping studies.

Robert Peter Gale, Junren Chen.

DOI: https://doi.org/10.1038/s41375-023-02002-y
Blood Adv. 2023 08 22. 7(16): 4671-4675

Framework of clonal mutations concurrent with WT1 mutations in adults with acute myeloid leukemia: Alliance for Clinical Trials in Oncology study.

Bhavana Bhatnagar, Jessica Kohlschmidt, Shelley J Orwick, Daelynn R Buelow, Sydney Fobare, Christopher C Oakes, Jonathan E Kolitz, Geoff Uy, Wendy Stock, Bayard L Powell, Deedra Nicolet, Erin K Hertlein, Krzysztof Mrózek, James S Blachly, Ann-Kathrin Eisfeld, Sharyn D Baker, John C Byrd.

DOI: https://doi.org/10.1182/bloodadvances.2023010482
Nat Commun. 2023 Aug 25. 14(1): 5208

MLL-AF4 cooperates with PAF1 and FACT to drive high-density enhancer interactions in leukemia.

Nicholas T Crump, Alastair L Smith, Laura Godfrey, Ana M Dopico-Fernandez, Nicholas Denny, Joe R Harman, Joseph C Hamley, Nicole E Jackson, Catherine Chahrour, Simone Riva, Siobhan Rice, Jaehoon Kim, Venkatesha Basrur, Damian Fermin, Kojo Elenitoba-Johnson, Robert G Roeder, C David Allis, Irene Roberts, Anindita Roy, Huimin Geng, James O J Davies, Thomas A Milne.

Aberrant enhancer activation is a key mechanism driving oncogene expression in many cancers. While much is known about the regulation of larger chromosome domains in eukaryotes, the details of enhancer-promoter interactions remain poorly understood. Recent work suggests co-activators like BRD4 and Mediator have little impact on enhancer-promoter interactions. In leukemias controlled by the MLL-AF4 fusion protein, we use the ultra-high resolution technique Micro-Capture-C (MCC) to show that MLL-AF4 binding promotes broad, high-density regions of enhancer-promoter interactions at a subset of key targets. These enhancers are enriched for transcription elongation factors like PAF1C and FACT, and the loss of these factors abolishes enhancer-promoter contact. This work not only provides an additional model for how MLL-AF4 is able to drive high levels of transcription at key genes in leukemia but also suggests a more general model linking enhancer-promoter crosstalk and transcription elongation.

DOI: https://doi.org/10.1038/s41467-023-40981-9
Autophagy. 2023 Aug 23.

Autophagy preserves hematopoietic stem cells by restraining MTORC1-mediated cellular anabolism.

Mariana Borsa, Sandrine Obba, Felix C Richter, Hanlin Zhang, Thomas Riffelmacher, Joana Carrelha, Ghada Alsaleh, Sten Eirik W Jacobsen, Anna Katharina Simon.

  Adult stem cells are long-lived and quiescent with unique metabolic requirements. Macroautophagy/autophagy is a fundamental survival mechanism that allows cells to adapt to metabolic changes by degrading and recycling intracellular components. Here we address why autophagy depletion leads to a drastic loss of the stem cell compartment. Using inducible deletion of autophagy specifically in adult hematopoietic stem cells (HSCs) and in mice chimeric for autophagy-deficient and normal HSCs, we demonstrate that the stem cell loss is cell-intrinsic. Mechanistically, autophagy-deficient HSCs showed higher expression of several amino acid transporters (AAT) when compared to autophagy-competent cells, resulting in increased amino acid (AA) uptake. This was followed by sustained MTOR (mechanistic target of rapamycin) activation, with enlarged cell size, glucose uptake and translation, which is detrimental to the quiescent HSCs. MTOR inhibition by rapamycin treatment in vivo was able to rescue autophagy-deficient HSC loss and bone marrow failure and resulted in better reconstitution after transplantation. Our results suggest that targeting MTOR may improve aged stem cell function, promote reprogramming and stem cell transplantation.

Keywords:  Autophagy; MTOR; amino acids; hematopoietic stem cells; rapamycin; translation

DOI:  https://doi.org/10.1080/15548627.2023.2247310
Cancer Discov. 2023 Aug 25. pii: CD-22-1338. [Epub ahead of print]

BCL2 inhibition reveals a dendritic cell-specific immune checkpoint that controls tumor immunosurveillance.

Liwei Zhao, Peng Liu, Misha Mao, Shuai Zhang, Camille Bigenwald, Charles-Antoine Dutertre, Christian H K Lehmann, Hui Pan, Nicolas Paulhan, Lukas Amon, Aitziber Buque, Takahiro Yamazaki, Lorenzo Galluzzi, Benoit Kloeckner, Aymeric Silvin, Yuhong Pan, Hui Chen, Ai-Ling Tian, Pierre Ly, Diana Dudziak, Laurence Zitvogel, Oliver Kepp, Guido Kroemer.

We developed a phenotypic screening platform for the functional exploration of dendritic cells (DC). Here, we report a genome-wide CRISPR screen that revealed BCL2 as an endogenous inhibitor of DC function. Knockout of BCL2 enhanced DC antigen presentation and activation as well as the capacity of DCs to control tumors and to synergize with PD-1 blockade. The pharmacological BCL2 inhibitors venetoclax and navitoclax phenocopied these effects and caused a cDC1-dependent regression of orthotopic lung cancers and fibrosarcomas. Thus, solid tumors failed to respond to Bcl2 inhibition in mice constitutively devoid of cDC1, and this was reversed by the infusion of DCs. Moreover, cDC1 depletion reduced the therapeutic efficacy of BCL2 inhibitors alone or in combination with PD-1 blockade and treatment with venetoclax caused cDC1 activation, both in mice and in patients. In conclusion, genetic and pharmacological BCL2 inhibition unveils a DC-specific immune checkpoint that restrains tumor immunosurveillance.

DOI: https://doi.org/10.1158/2159-8290.CD-22-1338
Blood. 2023 Aug 24. pii: blood.2023021119. [Epub ahead of print]

Lineage-specific detection of residual disease predicts relapse in chronic myeloid leukemia patients stopping therapy.

Ilaria Stefania Pagani, Naranie Shanmuganathan, Phuong Dang, Verity A Saunders, Randall Grose, Chung Hoow Kok, Jane James, Molly Tolland, Jodi A Braley, Haley Kristen Altamura, David T Yeung, Susan Branford, Agnes Sm Yong, Timothy P Hughes, David M Ross.

Chronic myeloid leukemia (CML) patients who are eligible for treatment-free remission (TFR) may still relapse after tyrosine kinase inhibitor (TKI) cessation. There is a need for accurate predictors of outcome to enable patients with a favorable profile to proceed while avoiding futile attempts. Sensitive detection of residual disease in total leukocytes at treatment cessation is associated with relapse, but is not highly discriminatory, likely because it is a composite measure of residual leukemia derived from different cell lineages whereas only some lineages are relevant for relapse. We prospectively measured BCR::ABL1 DNA as a predictive yes/no binary test in five cellular fractions from 48 patients meeting conventional criteria for TKI discontinuation. The median BCR::ABL1 DNA level was higher in granulocytes and in T cells, but not in other lineages, in patients who relapsed. In the 40 patients undergoing a first TFR attempt we defined three groups with differing relapse risk: granulocytes-positive (100%), granulocytes-negative/T cells-positive (67%), and granulocytes-negative /T cells-negative (25%). These data show the critical importance of lineage-specific assessment of residual disease in the selection of patients who can attempt TFR with a high expectation of success, and concurrently defer patients who have a high probability of relapse.

DOI: https://doi.org/10.1182/blood.2023021119
Blood Cancer J. 2023 Aug 22. 13(1): 128

Favorable outcomes of NPM1mut AML patients are due to transcriptional inactivation of FOXM1, presenting a new target to overcome chemoresistance.

I Khan, A Kaempf, S Raghuwanshi, M Chesnokov, X Zhang, Z Wang, A Domling, J W Tyner, C Camacho, A L Gartel.

DOI: https://doi.org/10.1038/s41408-023-00898-4
Nat Ecol Evol. 2023 Aug 24.

Evolutionary determinants of curability in cancer.

Marcela Braga Mansur, Nandita M deSouza, Rachael Natrajan, Lisa M Abegglen, Joshua D Schiffman, Mel Greaves.

The emergence of drug-resistant cells, most of which have a mutated TP53 gene, prevents curative treatment in most advanced and common metastatic cancers of adults. Yet, a few, rarer malignancies, all of which are TP53 wild type, have high cure rates. In this Perspective, we discuss how common features of curable cancers offer insights into the evolutionary and developmental determinants of drug resistance. Acquired loss of TP53 protein function is the most common genetic change in cancer. This probably reflects positive selection in the context of strong ecosystem pressures including microenvironmental hypoxia. Loss of TP53's functions results in multiple fitness benefits and enhanced evolvability of cancer cells. TP53-null cells survive apoptosis, and tolerate potent oncogenic signalling, DNA damage and genetic instability. In addition, critically, they provide an expanded pool of self-renewing, or stem, cells, the primary units of evolutionary selection in cancer, making subsequent adaptation to therapeutic challenge by drug resistance highly probable. The exceptional malignancies that are curable, including the common genetic subtype of childhood acute lymphoblastic leukaemia and testicular seminoma, differ from the common adult cancers in originating prenatally from embryonic or fetal cells that are developmentally primed for TP53-dependent apoptosis. Plus, they have other genetic and phenotypic features that enable dissemination without exposure to selective pressures for TP53 loss, retaining their intrinsic drug hypersensitivity.

DOI: https://doi.org/10.1038/s41559-023-02159-w
Nature. 2023 Aug 23.

Non-cell-autonomous cancer progression from chromosomal instability.

Jun Li, Melissa J Hubisz, Ethan M Earlie, Mercedes A Duran, Christy Hong, Austin A Varela, Emanuele Lettera, Matthew Deyell, Bernardo Tavora, Jonathan J Havel, Su M Phyu, Amit Dipak Amin, Karolina Budre, Erina Kamiya, Julie-Ann Cavallo, Christopher Garris, Simon Powell, Jorge S Reis-Filho, Hannah Wen, Sarah Bettigole, Atif J Khan, Benjamin Izar, Eileen E Parkes, Ashley M Laughney, Samuel F Bakhoum.

Chromosomal instability (CIN) is a driver of cancer metastasis1-4, yet the extent to which this effect depends on the immune system remains unknown. Using ContactTracing-a newly developed, validated and benchmarked tool to infer the nature and conditional dependence of cell-cell interactions from single-cell transcriptomic data-we show that CIN-induced chronic activation of the cGAS-STING pathway promotes downstream signal re-wiring in cancer cells, leading to a pro-metastatic tumour microenvironment. This re-wiring is manifested by type I interferon tachyphylaxis selectively downstream of STING and a corresponding increase in cancer cell-derived endoplasmic reticulum (ER) stress response. Reversal of CIN, depletion of cancer cell STING or inhibition of ER stress response signalling abrogates CIN-dependent effects on the tumour microenvironment and suppresses metastasis in immune competent, but not severely immune compromised, settings. Treatment with STING inhibitors reduces CIN-driven metastasis in melanoma, breast and colorectal cancers in a manner dependent on tumour cell-intrinsic STING. Finally, we show that CIN and pervasive cGAS activation in micronuclei are associated with ER stress signalling, immune suppression and metastasis in human triple-negative breast cancer, highlighting a viable strategy to identify and therapeutically intervene in tumours spurred by CIN-induced inflammation.

DOI: https://doi.org/10.1038/s41586-023-06464-z
Cell Rep. 2023 Aug 18. pii: S2211-1247(23)00976-2. [Epub ahead of print]42(8): 112965

Distinct mutational processes shape selection of MHC class I and class II mutations across primary and metastatic tumors.

Michael B Mumphrey, Noshad Hosseini, Abhijit Parolia, Jie Geng, Weiping Zou, Malini Raghavan, Arul Chinnaiyan, Marcin Cieslik.

  Disruption of antigen presentation via loss of major histocompatibility complex (MHC) expression is a strategy whereby cancer cells escape immune surveillance and develop resistance to immunotherapy. Here, we develop the personalized genomics algorithm Hapster and accurately call somatic mutations within the MHC genes of 10,001 primary and 2,199 metastatic tumors, creating a catalog of 1,663 non-synonymous mutations that provide key insights into MHC mutagenesis. We find that MHC class I genes are among the most frequently mutated genes in both primary and metastatic tumors, while MHC class II mutations are more restricted. Recurrent deleterious mutations are found within haplotype- and cancer-type-specific hotspots associated with distinct mutational processes. Functional classification of MHC residues reveals significant positive selection for mutations disruptive to the B2M, peptide, and T cell binding interfaces, as well as to MHC chaperones.

Keywords:  CP: Cancer; CP: Immunology; HLA; MHC; cancer; evolution; genomics; immunogenetics; selection; somatic mutations

DOI:  https://doi.org/10.1016/j.celrep.2023.112965