bims-tremyl Biomed News
on Therapy resistance biology in myeloid leukemia
Issue of 2026–03–01
fifty-two papers selected by
Paolo Gallipoli, Barts Cancer Institute, Queen Mary University of London



  1. Blood. 2026 Feb 24. pii: blood.2024027853. [Epub ahead of print]
      Targeting mitochondrial oxidative phosphorylation (OXPHOS) enhances the effects of standard chemotherapy and overcomes treatment resistance in pre-clinical models of acute myeloid leukaemia (AML). So far, the few clinically available OXPHOS inhibitors have shown adverse effects or limited potency in clinical trials, therefore, identification of safe and effective drugs that can target mitochondrial metabolism in AML is critical. Here, we performed a high-throughput drug-repurposing screen, designed to identify clinically applicable OXPHOS-specific inhibitors through nutrient sensing. We uncover itraconazole, an FDA-approved antifungal compound, as a potent OXPHOS inhibitor in AML cells. Mechanistically, through stable isotope-assisted metabolomics and functional studies, we reveal that CYP51A1, which is part of the cytochrome P450 family and the prime target of azole antifungals, is involved in mitochondrial respiration and ETC complex I activity in AML cells. Critically, we demonstrate that itraconazole and related azole antifungals interfere with tricarboxylic acid cycle activity and inhibit OXPHOS through the inhibition of electron transport chain complex I activity. Over-expression of yeast NADH dehydrogenase-1 (NDI1) restored mitochondrial NADH oxidation and complex I activity upon itraconazole treatment. Using patient-derived cells and pre-clinical xenograft models, we demonstrate that itraconazole targets therapy-resistant leukaemic stem cells (LSCs) when used in combination with cytarabine, highlighting the repurposing potential for itraconazole as a clinically safe and effective therapeutic option for AML LSC eradication.
    DOI:  https://doi.org/10.1182/blood.2024027853
  2. Res Sq. 2026 Feb 09. pii: rs.3.rs-8704827. [Epub ahead of print]
      Aging is strongly associated with the incidence of clonal hematopoiesis (CH) and myeloid malignancies. However, the role of aging in the clonal selection for CH mutations is not well understood. In a mouse model of CH, we observe that transplanted Tet2 KO hematopoietic stem cells (HSC) from old donor mice expand at a faster rate than young irrespective of the age of the recipient mice; that this acceleration is observed by middle age; and that it is primarily due to the aging-associated reduction in fitness of aged competitor non-mutant HSC. Mechanistically, in both mice and humans, we found that aged HSC exhibit enhanced activation of a RUNX1 transcriptional program and increased expression of ribosomal protein genes inducing a p53-mediated stress response, and that these changes are abrogated by Tet2/TET2 inactivation. Thus, aging creates the conditions that foster clonal expansion of Tet2, Runx1 and Trp53 mutant HSC promoting CH.
    DOI:  https://doi.org/10.21203/rs.3.rs-8704827/v1
  3. Leukemia. 2026 Feb 26.
      Somatic mutations in RNA splicing regulators, including the serine/arginine-rich protein SRSF2, are frequently observed in myeloid malignancies. Using mouse models and primary human samples, we investigated the impact of SRSF2 mutations on erythropoiesis. We found reduced erythropoiesis in Srsf2P95H versus wild-type mice upon stress-induced erythropoiesis and identified that SRSF2 mutations correlate with reduced hemoglobin in JAK2-mutant patients with myeloproliferative neoplasms (MPN). Consistent with this, Jak2V617F-Srsf2P95H versus Jak2V617F mice displayed reduced red blood cell counts and erythroid precursor frequencies. RNA-sequencing on erythroid precursors showed reduced expression of heme metabolism and mitotic spindle-related genes, and increased expression of mTORC1 signaling in Srsf2P95H versus wild-type cells. RNA splicing analyses on the same cells and on human patient samples identified aberrant FYN splicing in SRSF2mut cells, with increased aberrant FYNB over normal FYNT transcripts. FYNB, but not FYNT, expression resulted in reduced erythroid differentiation and increased phosphorylation of mTORC1 downstream target S6. Additionally, increased S6 phosphorylation was confirmed in primary Srsf2P95H erythroid cells. mTORC1 pathway inhibition using rapamycin normalized FYNB- and Srsf2P95H-induced impaired erythropoiesis and significantly increased erythroid colony formation of SRSF2-mutant myelodysplastic neoplasm (MDS) bone marrow cells. Our data reveal targetable molecular mechanisms of impaired erythropoiesis in SRSF2-mutant cells.
    DOI:  https://doi.org/10.1038/s41375-026-02892-8
  4. Blood. 2026 Feb 24. pii: blood.2025031486. [Epub ahead of print]
      Menin inhibitors (MI) disrupt the binding of Menin to MLL1 leading to repression of MLL1 or MLL1-fusion protein (FP) target genes, including reduced levels of HOXA9 and MEIS1 in AML with mutant (mt) NPM1 or MLL1-rearrangement (r). While MIs are relatively well-tolerated and induce clinical remissions, these are often short-lived due to development of resistance followed by AML relapse. Through repeated shocks with the MI SNDX-50469, a precursor tool compound to revumenib, followed by recovery, we developed MI-resistant (MITR) AML MV4-11 and OCI-AML3 cells. Present studies show that, compared to MI-sensitive parental cells, MITR cells exhibit an altered epigenome, transcriptome and proteome, without Menin mutations. Through a CRISPR screen, novel druggable MI co-enrichments were identified and targeted, including BRD4, SMARCA4, and CREBBP. Co-treatment with the MI and the SMARCA4/SMARCA2 (BRG1/BRM) inhibitor FHD-286 or the BET proteins inhibitor OTX015 (birabresib), synergistically induced in vitro lethality in MITR and MI-resistant AML cells expressing the mutant Menin (M327I), as well as in patient-derived (PD) AML cells with MLL1-r or mtNPM1 that exhibited ex vivo resistance to MI. Compared to each drug alone, co-treatment with SNDX-5613 (revumenib) and FHD-286 or OTX015 and FHD-286 significantly reduced the in vivo AML burden and improved survival of the immune depleted mice, without inducing significant toxicity, in the xenograft models of MITR and MI-resistant PD MLL1-r AML cells. These findings highlight novel, targeted, drug combinations that overcome MI resistance in AML cells with MLL1-r or mtNPM1.
    DOI:  https://doi.org/10.1182/blood.2025031486
  5. Leukemia. 2026 Feb 24.
      While TP53 mutations in myeloproliferative neoplasms (MPN) are associated with an increased risk of leukemic transformation, not all patients carrying a TP53 mutation progress. To better risk-stratify MPN patients with TP53 mutations, we analyzed data from 1540 patients treated at four specialized cancer centers. Among them, 1429 had wildtype TP53 and 111 had mutations in the TP53 gene. At first MPN diagnosis, 32% had polycythemia vera, 39% had essential thrombocythemia, and 25% had primary myelofibrosis. Among all MPN patients with TP53 mutations, presence of fibrosis in the bone marrow (hazard ratio (HR): 3.84, 95% CI: 1.98-7.43), multi-hit TP53 mutation status (HR: 2.74, 95% confidence interval (CI): 1.52-4.97), and higher PHANTM score (HR: 1.87, 95% CI: 1.02-3.42) were associated with worse OS in a multivariable analysis. Based on these variables, we developed a risk model to identify TP53-mutated MPN patients who are at high risk for inferior OS. Median OS from time of TP53 detection was 0.5 years in high-risk patients, compared to 2.3 years for patients with intermediate risk and 6.3 years for patients with low risk. This scoring system may help refine risk stratification for chronic phase MPN patients harboring TP53 aberrations.
    DOI:  https://doi.org/10.1038/s41375-026-02885-7
  6. Blood. 2026 Feb 26. pii: blood.2025031202. [Epub ahead of print]
      Altered lipid metabolism enables growth of acute myeloid leukemia (AML) cells. While mitochondrial lipid oxidation is well characterized, the contribution of peroxisomal fatty acid oxidation (pFAO) is unclear. In this study, we demonstrate that AML cells upregulate the peroxisomal very-long-chain fatty acid (VLCFA) transporter ABCD1 and increase endogenous levels of pFAO relative to healthy hematopoietic cells. Genetic silencing or pharmacological inhibition of ABCD1, with eicosenol, impairs pFAO causing accumulation of VLCFAs and selective AML cell death in vitro and in vivo. Loss of ABCD1 disrupts peroxisomal fatty acid import and lipid homeostasis in AML, while normal progenitors remain viable by upregulating glycolysis. In murine models, ABCD1 inhibition with eicosenol reduces leukemia burden and prolongs survival without toxicity. These findings identify ABCD1 as a regulator of pFAO and a novel anti-AML therapeutic target.
    DOI:  https://doi.org/10.1182/blood.2025031202
  7. bioRxiv. 2026 Feb 17. pii: 2026.02.16.706171. [Epub ahead of print]
      Fibrotic remodeling of the bone marrow (BM) niche is a characteristic feature of myelofibrosis (MF) that contributes to disease progression. In MF, mesenchymal stromal cells (MSCs) produce excessive amounts of inflammatory cytokines and extracellular matrix, leading to BM fibrosis, impaired blood production, extramedullary hematopoiesis, and progressive BM failure. While the genetic events that initiate MF in hematopoietic cells are well defined, our understanding of the mechanisms responsible for BM fibrosis remains incomplete. Here, we show that transcription factor EBF1 is a key regulator of the fibrotic gene program in mouse and human MSCs. EBF1 is upregulated in pre-fibrotic MSCs, while mice with MSC-specific deletion of Ebf1 exhibit reduced BM fibrosis, decreased expansion of myeloid cells and splenomegaly when transplanted with hematopoietic progenitors harboring the MF driver mutation MPL W515L . Moreover, we identify ITGB8 as an EBF1-regulated gene with therapeutic potential. MF mice treated with ITGB8-neutralizing antibodies or with MSC-specific Itgb8 deletion show reduced disease burden, as indicated by decreased marrow fibrosis, significantly reduced frequencies of MPL mutant cells, and reduced inflammation in the BM. Our data indicate that targeting the EBF1-ITGB8 axis in the MF MSCs may have therapeutic benefits.
    DOI:  https://doi.org/10.64898/2026.02.16.706171
  8. Blood Adv. 2026 Feb 24. 10(4): 939-950
       ABSTRACT: Acute myeloid leukemia (AML) is driven by diverse genetic abnormalities. We investigated clinical and molecular differences between clinically defined secondary AML following antecedent MDS, molecularly defined secondary type AML (st-AML), molecularly defined MDS/AML (st-MDS/AML; 10%-19% blasts) and other newly diagnosed AML (de novo AML). We also examined the prognostic value of molecular measurable residual disease (MRD) in st-AML. This retrospective cohort study included 2684 intensively treated patients with AML. Diagnostic (n = 2684) and complete remission (CR; n = 436) samples were sequenced using a 54-gene panel targeting frequently mutated genes in AML. Odds ratios were calculated to show the association between mutated genes and clinically defined sAML or de novo AML. Clinical outcomes of interest were overall survival (OS) and cumulative incidence of relapse (CIR). Not only the established mutations in ASXL1, BCOR, EZH2, SF3B1, SRSF2, STAG2, U2AF1 and ZRSR2 but also ETV6 was significantly associated with clinically defined sAML, which defined the molecular signature for st-MDS/AML and st-AML. No OS differences were observed between st-MDS/AML and st-AML. Molecularly defined st-AML, now combined with st-MDS/AML, had worse OS compared with ELN2022 favorable- (5-year OS 39.9% vs 70.4%; P< .001) and intermediate-risk (5-year OS 39.9% vs 48.9%; P = .005) patients with AML. MRD based solely on secondary type mutations lacked predictive value, whereas MRD of non-DTA mutations in CR was associated with increased CIR in st-AML (subdistribution hazard ratio [SHR] 3.25; P< .001). Molecularly defined st-AML, including st-MDS/AML, defines a distinct AML category with a unique genetic, clinical and treatment response profile, in which next-generation sequencing (NGS)-based MRD holds markedly prognostic significance.
    DOI:  https://doi.org/10.1182/bloodadvances.2025018408
  9. Blood Adv. 2026 Feb 24. 10(4): 987-998
       ABSTRACT: Prognostic risk categorization aids treatment selection for patients with acute myeloid leukemia (AML). Although the European LeukemiaNet (ELN) classifications (2017 and 2022) for AML have been used to stratify outcomes for patients receiving intensive chemotherapy, their application to patients receiving less intensive therapy, such as azacitidine plus venetoclax, has been less satisfactory. In response, a 4-gene classifier that stratifies older patients with AML unfit for intensive chemotherapy into those with higher benefit (wild type), intermediate benefit (FLT3-internal tandem duplication [ITD] or NRAS/KRAS mutation), or lower benefit (TP53 mutation) after azacitidine plus venetoclax treatment was developed. We hypothesized that this 4-gene classifier may also have prognostic utility in patients receiving low-dose cytarabine (LDAC) plus venetoclax. Surprisingly, neither the ELN 2022 criteria nor the 4-gene azacitidine-venetoclax classifier model adequately stratified prognosis in a cohort of 139 patients receiving LDAC plus venetoclax. Patients with concurrent NPM1 and FLT3-ITD/RAS variants performed surprisingly well with LDAC plus venetoclax (complete remission [CR]/CR with incomplete blood count recovery [CRi] rate, 92%; median overall survival [OS], 29.67 months). Data-driven (sequential bootstrapping and tree-based) and empirical analyses identified complex karyotype and/or presence of TP53 mutation as prognostically relevant molecular/cytogenetic risk markers. Patients with complex karyotype and/or TP53 mutation displayed poor clinical outcomes (CR/CRi, 25%; median OS, 3.48 months). Notably, 74% of the study population lacked these poor prognostic markers and had a 67% CR/CRi rate with a median OS of 14.92 months. Overall, these data support the importance of molecular subclassification in defining treatment outcomes to venetoclax-based therapies. These trials were registered at www.clinicaltrials.gov as #NCT02287233 and #NCT03069352.
    DOI:  https://doi.org/10.1182/bloodadvances.2025017083
  10. Blood Adv. 2026 Feb 24. 10(4): 1293-1300
       ABSTRACT: Aplastic anemia (AA) is a bone marrow failure syndrome resulting from the immune destruction of hematopoietic stem cells. Clonal hematopoiesis (CH) is characterized by expansion of progenitor hematopoietic stem cells that harbor leukemogenic driver mutations. It has previously been shown that individuals with AA have a high prevalence of CH. However, the association between CH and AA remains unknown. We conducted a prospective, matched cohort study within the UK Biobank from 2006 to 2022. Individuals with CH were ascertained based on whole-exome sequencing data. For each individual with CH, we randomly selected 10 individuals without CH matched by sex, birth year, and ethnicity from the study population. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) of AA associated with CH using a Cox regression model. We also studied the association by different mutations of CH. We identified 14 471 individuals with CH, and 144 323 matched individuals free of CH. Individuals with CH had a higher risk of AA (HR, 2.72; 95% CI, 2.16-3.43) than the reference group. The increase was greater for individuals with CH mutations in SRSF2 (HR, 19.35; 95% CI, 11.07-33.80), TET2 (HR, 4.45; 95% CI, 3.14-6.29), ASXL1 (HR, 2.06; 95% CI, 1.06-4.00), or DNMT3A (HR, 1.88; 95% CI, 1.31-2.70). In conclusion, CH may precede the diagnosis of AA, particularly in those with SRSF2, TET2, ASXL1, and DNMT3A mutations. Further studies are needed to understand the nature of this association and potential shared pathogenic mechanisms between CH and AA.
    DOI:  https://doi.org/10.1182/bloodadvances.2024015776
  11. Sci Rep. 2026 Feb 26.
      Although the spleen has been implicated in myeloid malignancy progression, the underlying mechanisms and microenvironmental remodeling remain poorly understood. Here, we investigated how splenic mesenchymal stromal/progenitor cells (MSPCs) expressing the transcription factor T-cell leukemia homeobox 1 (Tlx1) influence hematopoiesis and myeloid disease progression. We assessed their impact on hematopoietic stem/progenitor cells (HSPCs), leukemic cell recruitment, and disease progression. In vitro, Tlx1-overexpressing splenic stromal cells promoted the proliferation and survival of HSPCs. In vivo, using a murine acute myeloid leukemia (AML) model, AML progression induced extramedullary hematopoiesis (EMH) in the spleen through Tlx1 upregulation in MSPCs. This Tlx1-dependent remodeling facilitated leukemic cell recruitment and retention, whereas Tlx1 ablation in MSPCs significantly reduced leukemic cell accumulation in the spleen. Prolonged EMH in vivo was associated with the development of a myeloid malignancy. Collectively, these findings demonstrate that Tlx1-driven remodeling of the splenic microenvironment supports HSPC expansion and fosters conditions that promote myeloid malignancy development. Thus, targeting Tlx1-mediated alterations in the splenic niche may represent a therapeutic strategy for AML and related myeloid malignancies.
    Keywords:  Extramedullary hematopoiesis; Leukemic niche; Mesenchymal stromal/progenitor cells (MSPCs); Myeloid malignancy; Spleen; Tlx1
    DOI:  https://doi.org/10.1038/s41598-026-41461-y
  12. JCI Insight. 2026 Feb 23. pii: e193779. [Epub ahead of print]11(4):
      Mutations in protein tyrosine phosphatase non-receptor type 11 (PTPN11) have been considered late acquired mutations in acute myeloid leukemia (AML) development. Using single-cell DNA sequencing, we found that PTPN11 mutations can occur as initiating events in some patients with AML when accompanied by strong oncogenic drivers, commonly NPM1 mutations. The resulting AML has a diverse set of variably differentiated myeloid cells with few myeloid cells that lack leukemic mutations. The role of Ptpn11 as a codriver was confirmed in a murine model that exhibits an AML phenotype with a comparable immune diversity that is serially engraftable and reconstituted from early precursor cells. Furthermore, lineage-negative bone marrow cells from these mice reconstitute the full diversity of mature myeloid cells, and these cells exhibit an altered cytokine response after physiologic stimulation. Our work highlights how PTPN11-mutated AML is derived from a multitude of codominant and late acquired aberrations that have a previously unrecognized differentiated myeloid clonal expansion potentially contributing to pathogenesis of the disease.
    Keywords:  Hematology; Leukemias; Molecular genetics; Mouse models; Oncology
    DOI:  https://doi.org/10.1172/jci.insight.193779
  13. Blood. 2026 Feb 27. pii: blood.2024027180. [Epub ahead of print]
      Bone marrow failure (BMF) syndromes are heterogenous diseases characterized by impaired hematopoiesis and risk of evolution to myelodysplastic syndrome (MDS) and leukemia. We report 6 unrelated individuals with variable BMF phenotypes and hypocellular MDS presenting at a median age of 10 years (4 weeks - 53 years). Genomic analysis revealed germline heterozygous variants in MDM4, including 4 null (frameshift, nonsense, and splice-site resulting in premature truncation confirmed by RNA sequencing) and 2 missense variants, of which one had previously been associated with a familial BMF syndrome. Mechanistically, MDM4 mutations are loss-of-function leading to enhanced p53 activation. We used CRISPR/Cas9 to delete MDM4 in healthy donor hematopoietic stem and progenitor cells (HSPCs). The resulting MDM4-haploinsufficient HSPCs exhibited increased p53 activity, impaired colony-forming capacity, and reduced engraftment potential in immunodeficient mice. Complementation studies revealed both p53-binding and RING-finger domains as necessary for MDM4-mediated hematopoietic regulation. To study variant effect in a confounder-free genetic background, we introduced patient-specific MDM4 variants into induced pluripotent stem cells (iPSCs). MDM4-mutant iPSCs yielded significantly reduced erythroid and myeloid cells and exhibited increased p53 activity, as evidenced by elevated p21 expression, confirming the role of MDM4 regulating hematopoiesis through p53. Transcriptome analysis of iPSC-derived hematopoietic cells revealed upregulation of p53 pathway. Importantly, one patient with MDS acquired loss-of-function TP53 mutations, suggesting maladaptive somatic rescue.Our findings establish MDM4 deficiency as a TP53 activating syndrome with features of BMF and variable hematopoietic manifestations. This study also highlights the critical role of the MDM4-p53 axis in maintaining hematopoietic homeostasis.
    DOI:  https://doi.org/10.1182/blood.2024027180
  14. Res Sq. 2026 Feb 13. pii: rs.3.rs-8725671. [Epub ahead of print]
      Despite therapeutic advances, relapse remains the leading cause of death in patients with acute myeloid leukemia (AML). Growth factor signaling controls AML survival, proliferation, relapse, and chemotherapy resistance. Here, we studied heparan sulfate proteoglycans, a class of molecules that bind growth factors via their heparan sulfate chains to change their signaling ability. Heparan sulfate-growth factor interactions are controlled by the addition of sulfate groups catalyzed by heparan sulfotransferases, such as those encoded by HS2ST1 and HS6ST1 . Using AML patient cohort analyses, we demonstrate that increased HS6ST1 expression is associated with worse survival and increased relapse risk for AML patients harboring KMT2A -rearrangements. Using cell line derived xenografts, we show that AML cells depleted of HS2ST1 , but not HS6ST1 , have increased bone marrow leukemic burden. Further, AML cells depleted of HS6ST1 are more sensitive to cytarabine than Control cells, suggesting that HS6ST1 regulates AML chemotherapy resistance. Heparan sulfate antagonism with surfen synergized with cytarabine to further support AML cell death compared to cytarabine alone. Mechanistically, we demonstrate that HS6ST1 depletion in AML cells reduces TGF-β1-mediated signaling, which diminishes cell survival upon cytarabine treatment. Together, our data show that HS6ST1 promotes AML cell chemotherapy resistance by supporting TGF-β1 signaling.
    DOI:  https://doi.org/10.21203/rs.3.rs-8725671/v1
  15. Br J Haematol. 2026 Feb 26.
      Post-transplant cyclophosphamide (PTCy) is associated with infectious and organ toxicities. Dose optimization may reduce these risks while maintaining efficacy. We initiated a prospective pilot study in July 2024 evaluating reduced-dose PTCy (35 mg/kg on days +3 and +4; PTCy70) with low-dose anti-thymocyte globulin (ATG) (2 mg/kg) in adults with acute myeloid leukaemia (AML) undergoing matched unrelated donor (MUD) transplantation. Outcomes were compared with a contemporary cohort receiving PTCy100 with ATG 2 mg/kg. Of 173 patients, 41 received PTCy70. Platelet engraftment was faster with PTCy70, 13 vs. 16 days (p < 0.001). In multivariable analysis, PTCy70 was associated with lower risk of bloodstream infections (hazard ratio [HR] 0.39, 95% confidence interval [CI], 0.19-0.78, p = 0.007). At day+100, the incidence of grade II-IV (30.4% vs. 20.3%, p = 0.17), grade III-IV acute graft-versus-host disease (GVHD) (3% vs. 3%, p = 0.08) and non-relapse mortality (3.8% vs. 2.8%, p = 0.67) were similar between groups. Cardiac events were less frequent with PTCy70 (5% vs. 17%; p = 0.06). No cases of sinusoidal obstruction syndrome were observed in the PTCy70 group. At 12 months, relapse (11.1% vs. 15.3%, p = 0.88) and overall survival (79.6% vs. 83.2%, p = 0.87) did not differ between groups. PTCy70 was associated with faster platelet engraftment, fewer bloodstream infections and cardiac events without compromising GVHD, relapse or survival, supporting evaluation in randomized trials.
    Keywords:  AML; GVHD; PTCy; allogeneic transplantation; reduced‐dose; unrelated donor
    DOI:  https://doi.org/10.1111/bjh.70380
  16. PLoS One. 2026 ;21(2): e0329048
      Acute myeloid leukemia (AML) is an aggressive malignancy of hematopoietic stem and progenitor cells characterized by profound metabolic dysregulation. Pyrimidine biosynthesis has emerged as a critical metabolic dependency in AML, but clinical translation has been hampered by unacceptable toxicity of current pyrimidine synthesis inhibitors. Since aspartate is an essential nutrient for pyrimidine biosynthesis, we investigated the role of aspartate import via the excitatory amino acid transporter 1 (EAAT1) in AML. We found that EAAT1 is broadly expressed across AML cell lines and patient samples, with enrichment in M4 and M5 subtypes and increasing levels following chemotherapy treatment. Pharmacological inhibition of EAAT1 impaired AML cell viability in vitro, but metabolomic profiling and nutrient rescue experiments showed that these effects were independent of intracellular aspartate levels. Moreover, AML cells cultured in aspartate-free medium maintained proliferation and did not become more sensitive to chemotherapy. EAAT1 inhibition in mice increased bone marrow plasma aspartate levels, confirming inhibition of cellular aspartate uptake, but did not affect growth or chemosensitivity of MLL-AF9-expressing AML cells in vivo. These findings suggest that AML cells possess several complementary mechanisms to support their aspartate requirements and that EAAT1 inhibition does not impair AML growth or response to chemotherapy.
    DOI:  https://doi.org/10.1371/journal.pone.0329048
  17. Eur J Haematol. 2026 Feb 24.
      Myelodysplastic syndromes/neoplasms (MDS) constitute a very heterogeneous group of clonal myeloid neoplasms characterized by a variable clinical course and recurrent genetic abnormalities. Their treatment relies on risk classification as lower or higher-risk categories by the original International Prognostic Scoring System (IPSS) or the current revised (IPSS-R) or molecular IPSS-M. Higher-risk MDS (HR-MDS) are clonal hematopoietic disorders characterized by significant cytopenias, dysplastic changes, and a high propensity for progression to acute myeloid leukemia (AML). Up to 40% of them usually progress to AML within two years of diagnosis. Allogeneic stem cell transplantation (HSCT) remains the only potential cure and standard of care for eligible patients. Despite standard treatments such as Allo-HSCT and hypomethylating agents (HMAs), outcomes remain suboptimal. Recent advances have led to the development of novel therapeutic strategies, such as BCL-2 inhibitors (venetoclax), IDH1/2 inhibitors (ivosidenib, enasidenib), CD47 inhibitors (magrolimab), TIM-3 inhibitors (sabatolimab), XPO1 inhibitors (eltanexor), NEDD8-activating enzyme inhibitors (pevonedistat), TP53-targeted agents (eprenetapopt), liposomal chemotherapy (CPX-351), and oral HMA formulations. Combinations of hypomethylating agents with these new drugs, as first-line treatment, have to date not proven more efficacious than HMA monotherapy. This review summarizes the current therapeutic landscape on novel therapies for HR-MDS, highlighting their mechanism of action, efficacy, and demonstrates the unmet clinical need for more effective therapies.
    Keywords:  HMA; IDH inhibitors; high‐risk MDS; myelodysplastic syndromes; novel therapies; targeted therapy; venetoclax
    DOI:  https://doi.org/10.1111/ejh.70146
  18. bioRxiv. 2026 Feb 11. pii: 2026.02.09.704856. [Epub ahead of print]
      Myeloproliferative neoplasms (MPNs) are sustained by mutated hematopoietic stem cells (HSCs). Existing therapies fail to eliminate this compartment, leaving allogeneic HSC transplantation as the only curative option. Recurrent MPN driver mutations in calreticulin ( CALRmut ) generate a C-terminal neopeptide that requires cell-surface expression for oncogenic signaling, making it an attractive immunologic target. However, it remains unknown if CALRmut is uniformly displayed on all MPN HSCs within hematopoietic microenvironments. We generated huAB2, a high-affinity CALRmut-specific humanized antibody, to use as the targeting domain for chimeric antigen receptor (CAR)-T cells. We show that CALRmut is consistently displayed on functional MPN HSCs and accessible in vivo . huAB2 CAR-T cells eradicate MPN-propagating CALRmut HSCs in patient-derived tumor xenograft models without antigen escape while preserving coexisting normal human and host hematopoiesis. These findings establish CALRmut display as an obligate feature of MPN HSC fitness and support the feasibility of curative, non-transplant immunotherapy for CALRmut MPNs.
    Significance: Therapies that eradicate cancer stem cells enable cure, but their feasibility is unknown. We establish an approach to potentially cure MPNs by proving mutant calreticulin to be a MPN stem cell marker that can be targeted by CAR-T cells to selectively wipe out disease in preclinical models of human MPNs.
    DOI:  https://doi.org/10.64898/2026.02.09.704856
  19. NPJ Precis Oncol. 2026 Feb 26.
      Acute myeloid leukemia (AML) is sustained by oncogenic signaling and stress-adaptive networks that enable proliferative sustenance and therapeutic resistance. Transcriptomic profiling of AML blasts revealed upregulation of FLT3, SYK, HOXA9/10, and CTNNB1 with elevated oxidative phosphorylation (OXPHOS). Proteasome inhibition induced phosphorylation-dependent ubiquitination and nuclear export of β-catenin, triggering stress signaling (p62/SQSTM1/c-JUN/NRF2) and apoptosis in FLT3ITD mutant AML blasts. Dual targeting of FLT3/SYK (TAK-659) and the proteasome (Ixazomib) showed strong synergy across genetically defined AML subsets, irrespective of FLT3 mutant status. In Tet2-/-;Flt3ITD AML-transplanted mice models, combination therapy markedly reduced leukemic burden, restored CD45.1⁺ normal hematopoiesis, corrected disease-associated cytopenias, and normalized hematopoietic stem and progenitor composition. In our phase I/II clinical trial, this combination therapy induced rapid leukemic clearance, early transcriptional silencing of HOXA/FLT3/NRF2 programs, and durable hematologic responses in refractory AML patients. These findings define a therapeutically targetable axis linking FLT3/SYK/β-catenin signaling to stress adaptation, provide a mechanistic basis for combinatorial targeting in high-risk AML. Trial registration: NCT04079738, Date of registration 03 September 2019.
    DOI:  https://doi.org/10.1038/s41698-026-01332-1
  20. Blood Adv. 2026 Feb 24. 10(4): 1260-1271
       ABSTRACT: Acute myeloid leukemia (AML) relapse after allogeneic hematopoietic stem cell transplant (HSCT) portends a dismal prognosis. One approach for reinvigorating a graft-versus-leukemia response is consolidation with donor lymphocyte infusions (DLI) or second HSCT (HSCT2). However, the role of DLI/HSCT2 in patients who achieve complete remission (CR) after salvage therapy is unclear. In this retrospective study, we evaluated the outcomes of 464 patients with post-HSCT AML relapse, focusing on those who achieved CR before consolidation with cellular therapy. In multivariable analysis (MVA), achieving CR after post-HSCT1 relapse was associated with improved overall survival (OS; hazard ratio [HR], 0.42; P< .0001). Of 133 patients (29%) who achieved CR after posttransplant AML relapse and before cellular therapy, 64 received DLI, 28 underwent HSCT2, and 41 received neither. Four-year outcomes from CR for the entire cohort (n = 133) were: OS 29%, relapse-free survival (RFS) 22%, cumulative incidence of relapse 58%, and nonrelapse mortality (NRM) 20%. In MVA, there was no association between receipt of DLI (HR, 0.87; P = .59) or HSCT2 (HR, 1.08; P = .83) and OS. Furthermore, we did not identify a benefit with DLI or HSCT2 with respect to RFS, relapse, or NRM. Patients with donor chimerism <90% at the time of CR had reduced 4-year OS (20% vs 32%; P = .03), as did measurable residual disease-positive patients (17% vs 62%; P = .024). Our results question the benefit of consolidation with DLI or HSCT2 in patients with AML who achieve CR, and we identify high-risk subgroups that should be the focus of future studies with larger cohorts.
    DOI:  https://doi.org/10.1182/bloodadvances.2025018139
  21. Haematologica. 2026 Feb 26.
      NPM1-mutated (NPM1mut) acute myeloid leukemia (AML) is generally classified as favorable-risk under the 2022 European LeukemiaNet (ELN-2022) guidelines, except in the presence of FLT3-internal tandem duplication or adverse-risk cytogenetics. However, the prognostic significance of co-occurring myelodysplasia-related gene (MRG) mutations remains unclear, with prior studies yielding inconsistent results. To clarify this issue, we conducted a systematic review and meta-analysis in accordance with PRISMA guidelines, searching PubMed, Embase, and MEDLINE through March 2025. MRG mutations were defined as pathogenic variants in ASXL1, BCOR, EZH2, SF3B1, SRSF2, STAG2, U2AF1, ZRSR2 and RUNX1, and the primary analysis incorporated studies regardless of RUNX1 inclusion. Data from ten cohorts across nine studies (one of which included an independent validation cohort), encompassing a total of 4,363 patients, were analyzed. Of these, 655 patients (15.0%) harbored co-occurring MRG mutations. Among the patients with ELN-2022 intermediate risk (n=1,294), 108 (8.3%) had MRG mutations. The presence of MRG mutations was significantly associated with inferior overall survival (pooled hazard ratio [HR] 1.30; 95% confidence interval [CI], 1.11-1.51; p.
    DOI:  https://doi.org/10.3324/haematol.2025.288081
  22. Cell Rep. 2026 Feb 23. pii: S2211-1247(26)00099-9. [Epub ahead of print]45(3): 117021
      Uridine diphosphate (UDP)-glucose ceramide glucosyltransferase (UGCG) is an enzyme that glycosylates ceramide and blunts its pro-apoptotic activity in cancer cells. Targeting UGCG sensitizes solid cancer cells to chemotherapy. However, whether targeting UGCG can sensitize acute myeloid leukemia (AML) cells to venetoclax remains unclear. Here, we found that the inhibition of UGCG genetically or with its inhibitor eliglustat efficiently suppressed growth and promoted apoptosis in AML cells. Moreover, eliglustat in combination with venetoclax increased apoptosis, reduced AML cell viability, and inhibited AML effectively both for primary AML cells and xenograft models. Mechanistically, the combination induced ceramide accumulation, which activated the endoplasmic reticulum (ER) stress-GRP78/PERK/CHOP axis. Interestingly, combinatory treatment activated RAB32, which led to mitochondrial fission through ER-mitochondria communication and DRP1 activation. These findings demonstrate that targeting UGCG in combination with venetoclax is an alternative combinatory strategy to treat AML and provide insights into ceramide-mediated cell death in anti-cancer therapies.
    Keywords:  CP: cancer; DRP1; RAB32; UGCG; acute myeloid leukemia; ceramide accumulation; endoplasmic reticulum stress; venetoclax
    DOI:  https://doi.org/10.1016/j.celrep.2026.117021
  23. Haematologica. 2026 Feb 26.
      Venetoclax (ven)+azacitidine (aza) is the standard of care for newly-diagnosed acute myeloid leukemia (AML) patients who are not candidates for intensive chemotherapy (IC). Because prognostic factors for ven/aza and IC differ, an AML patient fit for IC may derive more benefit from ven/aza. We therefore designed a trial for younger, newly-diagnosed AML patients with non-favorable risk disease to receive ven/aza regardless of "fitness" for IC. We aimed to understand toxicity and efficacy in this population, and retrospectively compared outcomes to matched IC patients. Newly-diagnosed non-favorable risk patients ≤60 were enrolled and received ven, dose escalated to 600mg/dailyx28 days, with aza 75mg/m2x7 days on a 28-day cycle. Subjects were encouraged to move expeditiously to allogeneic stem cell transplant (ASCT) in first remission. Thirty-six subjects enrolled. Median age was 49 (22-59). Grade ≥3 neutropenia(42%), anemia(33%), thrombocytopenia(53%) and febrile neutropenia(36%) were common. The overall response rate (ORR) was 25/36 (69%) with 19 (53%) complete remissions; 68% of responders achieved MRD-negativity. Most subjects (53%) bridged to ASCT, and the majority of non-responders were successfully salvaged with IC. The median progressionfree- survival (PFS) and overall survival (OS) have not been reached (median follow-up 2.9 years). Compared to IC matched controls, the ORR, ASCT rate and PFS were significantly improved (69% vs 44% [p=0.0495], 53% vs 28% [p-0.0290] and not reached vs 60.8 months [p=0.007]). Hospital days, transfusions and infectious complications were significantly reduced for ven/aza subjects. Ven/aza is feasible for newly-diagnosed, younger, non-favorable risk AML patients, and appears at least as effective as IC.
    DOI:  https://doi.org/10.3324/haematol.2025.300374
  24. Cell Death Dis. 2026 Feb 23.
      Leptin is abundant within marrow adipose tissue, yet its impact on acute myeloid leukemia (AML) therapy response is undefined. Here, we report that elevated bone-marrow leptin and blast-cell leptin-receptor (LEPR) levels strongly associate with poor cytarabine (Ara-C) clearance and reduced survival in newly diagnosed AML patients. Mechanistic and functional validation in human AML lines, primary blasts, and two syngeneic mouse models (MLL-AF9, AML1-ETO9a) shows that exogenous leptin markedly blunts Ara-C cytotoxicity, whereas the high-affinity LEPR antagonist Allo-aca restores chemosensitivity without altering baseline leukemia growth. Leptin up-regulates LEPR and triggers JAK2/STAT3 signaling that boosts mitochondrial complex Ⅰ activity, oxidative phosphorylation, and mitochondrial reactive oxygen species (mtROS); the resulting mtROS surge activates a compensatory antioxidant program that shields blasts from drug-induced oxidative damage. These data identify an adipokine-driven metabolic circuit governing AML chemoresistance and reveal LEPR blockade as a tractable strategy to improve outcomes, underscoring adipose-tumor crosstalk as a general therapeutic vulnerability.
    DOI:  https://doi.org/10.1038/s41419-026-08528-0
  25. Blood Adv. 2026 Feb 27. pii: bloodadvances.2025017575. [Epub ahead of print]
      Novel treatments that can improve disease course of essential thrombocythemia (ET) are needed. In this phase 2 trial, participants with ET who required cytoreduction and had inadequate response to or were intolerant of ≥1 standard therapy received bomedemstat at a starting dose of 0.6 mg/kg per day, titrated to achieve a target platelet count (200-400×109/L). Primary end points were safety and response, defined as a platelet count ≤400×109/L without new thromboembolic events. Seventy-three participants received bomedemstat. At 24 weeks, 49 of 64 evaluable participants (77%) had a response. Durable reductions in platelet count (≤400×109/L for ≥12 weeks) were observed in 52 of 72 participants (72%). Durable reduction in white blood cell count (<10×109/L for ≥12 weeks) was observed in 61 of 72 participants (85%); of 10 participants with elevated white blood cell count at baseline, 9 had normal white blood cell count (<10×109/L) at week 24. Hemoglobin levels remained stable. After 24 weeks of treatment, a decrease in variant allele frequency of CALR, JAK2, or MPL was observed in 39 of 46 (85%) evaluable participants. By week 24, 2 of 73 participants (3%) had experienced ≥1 thrombotic event and 15 of 73 (21%) experienced ≥1 hemorrhagic event. During overall treatment period, grade 3 or 4 adverse events (AEs) occurred in 34 of 73 participants (47%). AEs led to temporary treatment interruption in 29 participants (40%) and permanent discontinuation in 11 (15%). No participants died due to AEs. Bomedemstat had clinically relevant activity and manageable safety in participants with ET. Registration: NCT04254978 (Study of Bomedemstat in Participants With Essential Thrombocythemia [IMG-7289-CTP-201/MK-3543-003]).
    DOI:  https://doi.org/10.1182/bloodadvances.2025017575
  26. Blood Adv. 2026 Feb 24. 10(4): 1082-1093
       ABSTRACT: Measurable residual disease (MRD) monitoring for mutated NPM1 is increasingly used to guide treatment decisions in patients with acute myeloid leukemia (AML) carrying this mutation. NPM1-MRD positivity after induction has been shown to identify patients who may benefit from allogeneic hematopoietic cell transplantation (allo-HCT), and NPM1-MRD monitoring after allo-HCT can detect early relapse, enabling the prompt initiation of salvage therapy. However, recommendations for clinical decision-making based on peritransplant NPM1-MRD levels are missing. In this study, we retrospectively analyzed 172 patients with NPM1-mutant AML treated at 2 German centers to explore the predictive values of NPM1-MRD measured before and after allo-HCT. We found that pretransplant MRD negativity was a strong predictor of favorable long-term overall survival (OS). In contrast, patients with positive and negative NPM1-MRD status at day 30 after HCT showed comparable OS. Finally, statistically derived NPM1-MRD thresholds effectively stratified MRD-high and MRD-low patient groups with differential outcome, with 2 peritransplant MRD risk scores obtained by longitudinal integration. First, a combined score using MRD measurements before HCT and at day 30 HCT was used to guide early reduction of immunosuppression (concordance index [C-index], 0.737). Second, a combined score using MRD measurements before HCT and at day 30 and day 100 after HCT was used to guide later post-HCT interventions (C-index, 0.841; stratified 2-year OS groups, 100%, 90.1%, 57.1%, and 25.7%; P< .0001). This approach predicted OS better than age, FLT3-ITD status, or morphological remission status. We propose that in the peritransplant setting, NPM1-MRD thresholds are superior to conventional MRD analysis based on binary or log-step change data.
    DOI:  https://doi.org/10.1182/bloodadvances.2025017908
  27. Mol Cell. 2026 Feb 26. pii: S1097-2765(26)00098-5. [Epub ahead of print]
      Cancer functional genomics enables high-throughput target discovery and mechanistic investigation, yet its application has remained largely confined to mouse models and established human cancer cell lines. Direct functional interrogation of heterogeneous primary tumors offers a powerful opportunity to evaluate therapeutic targets and uncover cancer dependencies or resistance mechanisms. Here, we developed an optimized CRISPR-based platform for functional genomics in patient-derived xenograft and primary acute myeloid leukemia (AML) samples harboring diverse pathogenic mutations. Integrated in vitro and in vivo CRISPR-Cas9 knockout and CRISPR interference (CRISPRi) dropout screens validated known AML-biased targets and identified cis-regulatory elements essential for leukemic growth. Coupling pooled CRISPR perturbations with single-cell RNA sequencing (Perturb-seq) further resolved the perturbation-induced alterations in regulatory networks, cell cycle states, and cellular hierarchies in primary AML samples. Together, these studies establish a general and robust framework for leveraging CRISPR-based functional genomics to directly dissect cancer dependencies and cellular heterogeneity in primary AML patient samples.
    Keywords:  AML; CRISPR; PDX; Perturb-seq; funtional genomics; primary cells
    DOI:  https://doi.org/10.1016/j.molcel.2026.02.003
  28. medRxiv. 2026 Feb 11. pii: 2026.02.10.26345949. [Epub ahead of print]
      Allogeneic hematopoietic cell transplantation is the only curative option for many patients with acute myeloid leukemia (AML). In the current study, we designed and implemented a personalized assay, called v96, incorporating up to 96 mutations in 30 AML patients undergoing transplantation. The assay was performed on DNA derived in cells from the bone marrow as well as in cell-free plasma. All 30 (100%) of patients harbored molecular evidence of residual leukemia during remission that was detectable by the v96 assay, while only 6 (20%) had evidence of disease as assessed by conventional clinical assays. Furthermore, cell-free DNA from plasma proved to be more sensitive than DNA from cells of the bone marrow for identifying residual leukemia. The median number of mutants was 352-fold higher in plasma taken prior to transplantation for patients who relapsed compared to those who did not relapse. At two months post-transplantation, 27 of the 30 patients still harbored detectable leukemia as assessed by the v96 assay. Twenty-two of these patients had a subsequent decrease in leukemic burden assessed by the v96 assay, usually only after immunosuppression was discontinued and supporting a graft-versus-leukemia effect. These results document the feasibility of using a relatively large panel of carefully chosen mutations and a highly specific assay as non-invasive markers of therapeutic response in AML patients, minimizing the need for multiple bone marrow biopsies.
    STATEMENT OF SIGNIFICANCE: We report a blood test that tracks up to 96 patient-specific mutations and applied it to patients with AML who had undergone bone marrow transplantation. Using this test to evaluate cell-free plasma DNA, we found evidence of residual leukemia cells both during remission (prior to transplantation) in all patients, and two months following transplantation in 90% of patients. This test can mitigate the need for invasive bone marrow biopsies to follow patients with leukemia. Moreover, the test appears to be more accurate than standard assays for detecting residual leukemia, and has the potential to guide the timing of transplantation and subsequent therapeutic measures, thereby laying the foundation for future prospective studies.
    DOI:  https://doi.org/10.64898/2026.02.10.26345949
  29. Am J Hematol. 2026 Feb 27.
      It is an exciting era in leukemia owing to the development of novel targeted therapies and advances in genomics, pathophysiology, prognostication, and monitoring (e.g., highly sensitive measurable residual disease assays). Currently, most leukemias are effectively treated with immunotherapies (highly effective monoclonal antibodies targeting CD19 [blinatumomab], or CD22 [inotuzumab ozogamicin]), BCR::ABL1 tyrosine kinase inhibitors (TKIs; e.g., dasatinib, ponatinib), Bruton TKIs (e.g., ibrutinib, acalabrutinib), BCL-2 inhibitors (venetoclax), IDH1/2 inhibitors (ivosidenib, olutasidenib, and enasidenib), FLT3 inhibitors (e.g., midostaurin, quizartinib, and gilteritinib), menin inhibitors (revumenib, ziftomenib), and chimeric antigen receptor T-cell therapies. These novel agents and their judicious use in combination strategies have transformed the treatment landscape across all leukemias, significantly increased survival and quality of life for patients, and attenuated the need for intensive chemotherapy and hematopoietic stem cell transplantation. Leukemia subtypes, such as Philadelphia-positive acute lymphoblastic leukemia (incurable before 2000) and chronic lymphocytic leukemia (previously considered incurable) with historically dire prognoses were recently transformed to favorable leukemias with 5- and 10-year survival rates of 80+% and 90+%, respectively. The BCR::ABL1 TKIs resulted in normal life expectancy in chronic myeloid leukemia. Notable advances have also been made in AML with targeted therapies, although some subsets (older/unfit patients for intensive chemotherapy, complex karyotype, TP53-mutated, KMT2A-rearranged, and treated secondary AML) still have unfavorable outcomes. Herein, we provide a high-level overview of prominent clinical developments across all leukemias. In contemporary times, harnessing the benefits of novel targeted therapies and the evolving treatment landscape bolster the optimistic view that most, if not all, leukemias are curable.
    DOI:  https://doi.org/10.1002/ajh.70247
  30. JCI Insight. 2026 Feb 26. pii: e192126. [Epub ahead of print]
      Fanconi anemia (FA) is the most common bone marrow failure (BMF) syndrome. Beyond a role in DNA repair, FA genes have a role in suppressing DNA-RNA hybrids, termed R-loops, which can be generated via RNA polymerase (RNAP)-mediated transcription. However, how these processes, including a role in fate determination of hematopoietic stem cells (HSCs), are related to BMF is largely unknown. Additionally, single FA gene knockouts in mice do not recapitulate most phenotypes observed in FA patients. Thus, we generated a mouse model for FA by introducing heterozygous Setd2, which restricts RNAP-dependent transcription. Here, we show that FA patient-derived cells and Setd2+/- Fanca-/- HSCs share increased R-loop as well as dsRNA levels, and a ribosomal biogenesis defect. Further, Setd2+/- Fanca-/- HSCs display cell cycle arrest, mitotic errors and BMF phenotypes. Importantly, utilizing our Setd2+/- Fanca-/- mice, we discovered that Juglone, a pan RNAP inhibitor, reduces R-loop and dsRNA and reverses ribosomal biogenesis defects and mitotic errors, thereby rescuing BMF. In conclusion, this study establishes a novel mouse model that underscores a key role for R-loop formation, ribosomal biogenesis defects and mitotic errors in HSCs in driving BMF in Fanconi anemia. We also introduce a potential therapeutic avenue based upon pan-inhibition of RNA polymerases utilizing Juglone.
    Keywords:  Cell biology; Hematology; Hematopoietic stem cells
    DOI:  https://doi.org/10.1172/jci.insight.192126
  31. bioRxiv. 2026 Feb 11. pii: 2026.02.09.704594. [Epub ahead of print]
      Endolysosomal trafficking supports cellular homeostasis through coordinated regulation of extrinsic signaling inputs. Hematopoietic stem cell (HSC) function requires a tightly regulated balance between quiescence for long-term preservation and rapid activation for blood production. Although lysosomal regulation of metabolism and quiescence has been linked to stem cell maintenance, the contribution of endocytic routing to lysosomal function remains incompletely understood. Here, we show that quiescent HSCs rely on elevated endocytosis to maintain self-renewal. This activity is mediated in part by GPRASP2, a post-endosomal sorting protein. HSCs enriched in GPRASP2 are functionally dormant yet molecularly primed for activation however, in response to proliferative cues, dormant HSCs exhibit reduced signaling and proliferation. Disruption of GPRASP2-mediated endocytosis induces rapid proliferation and increased expression of signaling constituents, consistent with a model in which elevated endocytosis attenuates signaling through receptor internalization. Thus, we identify endocytosis as a mechanism by which HSCs limit functional exhaustion arising from chronic activation.
    DOI:  https://doi.org/10.64898/2026.02.09.704594
  32. Blood. 2026 Feb 25. pii: blood.2025032339. [Epub ahead of print]
      Clonal hematopoiesis of indeterminate potential (CHIP) is characterized by age-related somatic mutations in hematopoietic stem and progenitor cells (HSC/Ps) and is correlated with an increased risk of myeloid malignancies, elevated inflammatory pathways in circulating myeloid cells, higher all-cause mortality, chronic kidney disease, and cardiovascular disease. The pathophysiology of inflammatory bowel disease (IBD) is intrinsically linked to heightened inflammation. Nevertheless, the presence of CHIP in IBD and its role in the pathophysiology of IBD remains poorly elucidated. In the UK Biobank, CHIP was associated with an increased incidence of IBD. Females with CHIP had a 1.33-fold higher risk, which was further validated in All of Us data base (ßOR = 1.29). For Crohn's disease, DNMT3A mutations conferred a 1.81-fold increased incidence in females compared to non-DNMT3A-carriers, which rose to 2.09 for large clones (variant allele fraction ≥10%). In contrast, for ulcerative colitis, TET2 large clones were significantly associated, and only among individuals under 45. These associations were further identified using two-sample Mendelian randomization. In a mouse model of CHIP-IBD, HSC/Ps with Dnmt3a mutation demonstrated significantly worse pathophysiology compared to controls, due in part to heightened expression of Apurinic/apyrimidinic endonuclease 1 (APE1) in the bone marrow and colon. Treatment with the APE1/Ref-1 inhibitor APX3330 ameliorated CHIP-IBD driven by the Dnmt3a mutation.
    DOI:  https://doi.org/10.1182/blood.2025032339
  33. Blood Adv. 2026 Feb 24. 10(4): 1126-1133
       ABSTRACT: CPX-351, a novel liposomal formulation of cytarabine and daunorubicin, represents the standard of care in fit patients with acute myeloid leukemia with myelodysplasia-related changes (AML-MRC) and therapy-related AML (t-AML). Considering its better safety profile than conventional intensive chemotherapy, we investigated its cost-to-benefit ratio, in terms of overall survival and of mortality, in a large multicentric series of AML-MRC and t-AML receiving CPX-351 outside clinical trials between 2019 and 2022. Patients were classified as fit or unfit for intensive chemotherapy through a comprehensive evaluation of age, comorbidities, and performance status by adopting Italian Society of Hematology/Italian Society of Experimental Hematology/Gruppo Italiano per il Trapianto di Midollo Osseo (SIE/SIES/GITMO) criteria. Disease risk was defined according to the European LeukemiaNet 2017 classification. Before treatment start, 328 of 403 (81.4%) patients were classified as fit and 75 of 403 (18.6%) as unfit. Three hundred and ninety-six had a full genetic/cytogenetic profile, with 17 (4%) being categorized as favorable risk, 162 (41%) intermediate risk, and 217 (55%) adverse risk according to European LeukemiaNet 2017. After induction, 230 of 403 (57.1%) patients achieved complete remission, with no differences between fit (57.3%) and unfit (56%) patients. However, the 2 groups significantly differed in terms of survival (median overall survival, 18 months vs 8 months for fit and unfit patients, respectively) and of 28- and 100-day mortality (4.6% vs 10.7% at 28 days and 14.3% vs 32% at 100 days for fit and unfit patients, respectively). In conclusion, the SIE/SIES/GITMO criteria distinguished patient subgroups with different short- and long-term outcomes after treatment with CPX-351. The update or design of dedicated fitness criteria could represent a future and valid strategy to optimize the use of this specific treatment.
    DOI:  https://doi.org/10.1182/bloodadvances.2025017089
  34. Blood Adv. 2026 Feb 27. pii: bloodadvances.2025017456. [Epub ahead of print]
      Full engraftment and early immune reconstitution of donor hematopoietic stem cells (HSCs) after allogeneic HSC transplantation (allo-HSCT) are crucial. However, effective and safe clinical modality remains lacking. Here, very-late antigen (VLA-4) was identified as a pivotal target for HSC engraftment, and one of its agonists was identified, which significantly promotes donor HSC engraftment and long-term hematopoietic reconstitution by enhancing its self-renewal capacity in allogeneic transplantation and serial xenotransplantation mouse models. Furthermore, the VLA-4 agonist facilitated early immune reconstitution by augmenting T-cell differentiation from HSCs, with the reconstituted immune cells exhibiting potent antiviral effects without exacerbating acute graft-versus-host disease. Mechanistically, VLA-4 A2 activated ERK1/2 phosphorylation to regulate HSC function and lymphoid progenitor differentiation, without inducing leukemogenic gene expression. These findings underscore the significant clinical translational potential of the VLA-4 agonist in promoting HSC engraftment and early cellular immune reconstitution following allo-HSCT.
    DOI:  https://doi.org/10.1182/bloodadvances.2025017456
  35. Sci Transl Med. 2026 Feb 25. 18(838): eady2936
      Inactivation of tumor suppressor genes (TSGs) imparts a cellular fitness in cancers, including in acute myeloid leukemia (AML). The detection of silenced TSGs without direct mutations presents challenges in designing targeted cancer treatments, yet it also opens a therapeutic opportunity to restore their function. In this study, we identified the transcriptional repressor ZBTB7A as a TSG that is down-regulated in samples from patients with AML and is associated with poor survival outcomes. Loss of ZBTB7A amplifies TNF signaling, driving a dysfunctional inflammatory state that accelerates AML progression in vivo. Mechanistically, the mRNA decay factor ZFP36L2 binds to the 3' untranslated region (3'UTR) of ZBTB7A, promoting its transcript degradation in human AML cells. To identify therapeutic targets, we developed a CRISPR-based screening approach coupled with fluorescence in situ hybridization and flow cytometry (FISH-Flow), pinpointing the KDM4 family of histone demethylases as a vulnerability to restore ZBTB7A function. Pharmacologic inhibition of KDM4 up-regulated ZBTB7A expression, promoted terminal differentiation in patient-derived xenograft models, and demonstrated broad antileukemic efficacy across AML subtypes as well as preserved normal hematopoiesis. These findings reveal regulatory mechanisms of ZBTB7A and support epigenetic therapy as a promising strategy to reactivate its tumor suppressor function in hematologic cancers.
    DOI:  https://doi.org/10.1126/scitranslmed.ady2936
  36. bioRxiv. 2026 Feb 20. pii: 2026.02.18.706652. [Epub ahead of print]
      The pathological mechanisms and significance for the prevalent hotspot mutations in disordered protein regions are poorly understood. ASXL1 is an obligate co-factor for BAP1 in H2AK119 deubiquitination. ASXL1 mutations are very frequent in myeloid malignancies, and are mostly C-terminal truncating mutations concentrated in a specific disordered region of ASXL1. ASXL1 truncations are gain-of-function mutations that promote myeloid malignancies, but the underlying mechanisms remain poorly understood. Here we show that the frequently truncated mutants of ASXL1 possess an intrinsic property of forming phase-separated biomolecular condensates, and this property is normally suppressed by the frequently deleted regions. A disease-mutant of the endogenous ASXL1 in leukemia cells forms dynamic nuclear co-condensates with other endogenous factors important for gene activation. The ASXL1 disease-mutants can greatly enhance H2A deubiquitination activity of BAP1 in cells and in vitro reconstituted system, enhance myeloid leukemia cell growth, and promote leukemogenesis in a mouse transplant model by turning on myeloid leukemogenic transcriptional programs. However, substitution of residues important for condensation disrupted or impaired all these abilities, suggesting that the condensation property is crucially important for the ASXL1 mutants in promoting cancer. Moreover, we discover that the conserved negative charges in the highly disordered and frequently deleted region on ASXL1 suppress the condensation of the wild type ASXL1. Charge-neutralizing mutations in this region restores condensation of the full-length ASXL1, and are sufficient to turn ASXL1 into a leukemogenic protein. Biochemical, biophysical, and simulation analyses suggest the intramolecular interactions normally mask the N-terminal region in engaging intermolecular interactions required for phase separation, and disease truncations escape from the regulatory interactions and unleash the phase separation property to form nuclear hubs to promote expression of tumorigenic gene programs. Finally, by showing a striking correlation of the mutation frequencies with the condensation properties and leukemogenesis activity for a series of human patient mutations, we suggest that dysregulation of condensation is a central mechanism for ASXL1 mutations in promoting myeloid malignancies. This suggests that dysregulation of condensation may be a key mechanism for some of the prevalent hotspot disease mutations in the disordered proteomes.
    DOI:  https://doi.org/10.64898/2026.02.18.706652
  37. Cell Stem Cell. 2026 Feb 23. pii: S1934-5909(26)00033-0. [Epub ahead of print]
      The bone marrow is the primary site of blood and immune cell production in postnatal life. Current human models do not capture lympho-myeloid hematopoiesis and the stromal diversity needed for lifelong blood and immune maintenance. Here, we introduce comBO (combined bone and lympho-myeloid bone marrow organoid), a scalable induced pluripotent stem cell (iPSC)-derived system that generates osteolineage, vascular, lymphoid, and myeloid compartments within a single organoid. Developed under physioxia in granular microgel scaffolds, comBOs improve scalability and reproducibility and sustain long-term lympho-myeloid potential in serial organoid re-seeding assays. Incorporating healthy or malignant donor cells produces "chimeroids" that model physiological and pathological states. Using multiple myeloma as an exemplar, comBOs recapitulate niche remodeling and identify macrophage inhibitory factor (MIF) signaling as a disease driver. MIF inhibition reduces inflammation and myeloma proliferation, highlighting its therapeutic potential. comBOs offer a physiologically faithful bone marrow platform for disease modeling and therapeutic discovery in translational hematology and immunology.
    Keywords:  NAMs; biotechnology; bone; bone marrow; hematopoiesis; myeloma; new approach methodologies; organoid; organoid-on-chip; preclinical modeling
    DOI:  https://doi.org/10.1016/j.stem.2026.01.010
  38. Hemasphere. 2026 Feb;10(2): e70309
      Bone marrow fibrosis is the most extensive matrix remodeling of the microenvironment and can include de novo formation of bone (osteosclerosis). Spatiotemporal information on the contribution of distinct bone marrow niche populations to this process is incomplete. We demonstrate that fibrosis-inducing hematopoietic cells cause profibrotic reprogramming of perivascular CXCL12-abundant reticular (CAR) progenitor cells, resulting in loss of their hematopoiesis-support and upregulation of osteogenic and pro-apoptotic programs. In turn, peritrabecular osteolineage cells (OLCs) are activated in an injury-specific, Wnt-dependent manner, comparable to skeletal repair. OLCs fuel bone marrow fibrosis through their expansion and skewed differentiation, resulting in osteosclerosis and expansion of Ly6a+ fibroblasts. NCAM1 expression marks peritrabecular OLCs and their expansion into the central marrow is specific for fibrosis in mice and patients. Peritrabecular stromal β-catenin expression is linked to fibrosis in patients, and inhibition of Wnt signaling reduces bone marrow fibrosis and osteosclerosis, possibly being a clinically relevant therapeutic target.
    DOI:  https://doi.org/10.1002/hem3.70309
  39. Clin Cancer Res. 2026 Feb 23.
       PURPOSE: GCN2, one of the four kinases that activate the Integrated Stress Response to maintain proteostasis, has been shown to support cancer cell growth and survival in multiple preclinical cancer models. Acute myeloid leukemia (AML) is an aggressive hematological malignancy with dismal prognosis and high relapse rates that is marked by a dependency on finely tuned proteostasis. Here, we investigate the anti-leukemic potential of a new small-molecule GCN2 inhibitor, APL-4098.
    EXPERIMENTAL DESIGN: selectivity and potency of APL-4098 were assessed using biochemical and cell-based assays. Anti-leukemic effects were evaluated ex vivo in primary patient-derived AML and in vivo using cell line-derived (CDX) and patient-derived (PDX) xenograft models. Synergy of APL-4098 and venetoclax was examined in the PDX. RNA sequencing and metabolic assays were used to explore APL-4098 mechanism of action.
    RESULTS: APL-4098 exhibited nanomolar-range potency against and high selectivity for GCN2. APL-4098 showed strong anti-proliferative activity ex vivo across two independent cohorts of primary AML patient cells, including cytotoxic effects on the leukemia stem cells (LSCs) and in vivo, achieving 98% tumor growth inhibition in an AML CDX. In a PDX, APL-4098 preferentially depleted the LSC-enriched compartment and, in combination with venetoclax, reduced leukemia burden by over 98%. Transcriptomic and metabolic analyses revealed APL-4098 compromises mitochondrial function and elicits the mitochondrial unfolded protein response.
    CONCLUSIONS: APL-4098 is a novel, potent and selective GCN2 inhibitor with strong preclinical efficacy against AML cells, including LSCs. Our findings support APL-4098 as a promising candidate for AML treatment.
    DOI:  https://doi.org/10.1158/1078-0432.CCR-25-1444
  40. Blood Adv. 2026 Feb 26. pii: bloodadvances.2026019625. [Epub ahead of print]
      For over two decades, the mevalonate pathway has been in focus as an interesting therapeutic target in the Philadelphia-chromosome negative myeloproliferative neoplasms (MPNs). Initially explored for its potential in cytoreductive and antithrombotic therapy, the role of statins in MPNs is now experiencing a compelling renaissance. This renewed interest is fueled by the recognition of MPNs as "a human inflammation model," driven by chronic inflammation that fuels clonal expansion, premature atherosclerosis, fibrogenesis, and an increased risk of second cancers and comorbidities. Statins possess a wide spectrum of pleiotropic effects beyond lipid-lowering, including anti-inflammatory, antiproliferative, pro-apoptotic, anti-angiogenic, and antifibrotic properties. They dampen the activation of leukocytes, platelets, and endothelial cells. Recent epidemiological studies from Denmark demonstrate that statins protect against the development of MPNs in the general population. Furthermore, emerging clinical data suggest that statins enhance the efficacy of interferon-alpha (IFN-α), the only known therapy capable of directly targeting the malignant stem cell and inducing minimal residual disease (MRD) in a subset of patients. This review traces the 20-year journey of the statin-in-MPN concept, from its mechanistic rationale to the present, where a confluence of evidence from comorbid disease prevention and onco-immunology is supportive of their upfront use. I posit that we are at a watershed moment, where statins should be integrated into the upfront treatment of MPNs and in combination therapy strategies, particularly with IFN-α, and potentially with ruxolitinib and metformin, to extinguish the chronic inflammatory drive and fundamentally alter the natural history of these neoplasms.
    DOI:  https://doi.org/10.1182/bloodadvances.2026019625
  41. Haematologica. 2026 Feb 26.
      Immune mediated aplastic anaemia (AA) is a bone marrow failure syndrome characterised by cytotoxic CD8 mediated autoimmune suppression of haematopoietic stem progenitor cells (HSPCs) resulting in varying degrees of peripheral blood cytopenias. Treatment with immunosuppressive therapy and haematopoietic stem cell transplantation are not applicable to all the patients and effective responses occur in a proportion of patients only, highlighting the unmet need for alternative treatments. We have previously shown a reduction in number and function of regulatory T cells (Tregs) in AA patients and their functional restoration following in vitro expansion that laid the foundations for this Phase 1 trial. Required number of Tregs were collected from leukapheresis and expanded under GMP conditions from all 6 patients in the trial who were resistant/refractory to standard form of treatments. The trial design included 2 doses of autologous Tregs (5×106 /kg) administered 2 weeks apart. Mass cytometry, single cell sequencing and cytokine profiling was performed on blood samples collected at various timepoints. Tregs were successfully expanded to required doses from all 6 patients with no adverse or immune related events in any of the patients. Haematological responses were observed in 3 patients. In addition, we were able to track the persistence of the expanded Tregs in vivo, correlate clinical efficacy with the accumulation of clusters of Tregs post-infusion, and identify phenotypic markers in the infusion product that correlate with in vivo expansion. Tregs from AA patients are expandable, safe for infusion, and may help modulate the abnormal immune milieu associated with AA, with induction of clinical response.
    DOI:  https://doi.org/10.3324/haematol.2025.288962
  42. Br J Haematol. 2026 Feb 24.
    VEXNET‐UK MDT
      The objective of this study was to describe the establishment, structure and influence of the United Kingdom national multidisciplinary team (MDT) for vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome and to assess its clinical outputs and perceived value among participating clinicians. All patients discussed at the national VEXAS MDT between June 2024 and May 2025 were included. Clinical information was extracted from standardised referral forms, and MDT recommendations were reviewed. An anonymised questionnaire evaluated clinicians' experience of the MDT. Forty-two patients from 27 centres were reviewed; 36 (85.7%) had confirmed VEXAS syndrome and 6 had VEXAS-like disease. Almost all were male (41/42), with a median age of 70 years. Before MDT review, 62% received corticosteroid monotherapy. MDT recommendations favoured steroid-sparing strategies, with marked increases in the use of azacitidine (1-22 patients) and tocilizumab (5-15 patients), alongside reduced use of conventional disease-modifying anti-rheumatic drugs (DMARDs). Four patients were referred for haematopoietic stem cell transplantation. Twenty of 43 MDT members completed the survey, reporting greater confidence in managing VEXAS and valuing the MDT's educational and collaborative benefits. The national VEXAS MDT supported evidence-informed, multidisciplinary decision-making, promoted more targeted therapy and strengthened clinical confidence and collaboration in the absence of formal treatment guidelines.
    Keywords:  UBA1; VEXAS syndrome; azacitidine; corticosteroids; haematology; multidisciplinary team; rheumatology
    DOI:  https://doi.org/10.1111/bjh.70365
  43. Nat Commun. 2026 Feb 24.
      Embryonic hematopoietic stem and progenitor cells (HSPCs) have the clinically valuable ability to undergo substantial proliferative expansion while maintaining multipotency, which remains difficult to replicate in culture. Here, we show that newly specified HSPCs achieve this unique state by precise spatio-temporal regulation of reactive oxygen species (ROS) via Bnip3lb-associated developmentally-programmed mitophagy, a distinct autophagic regulatory mechanism from that of adult HSPCs. While ROS drives HSPC specification in the dorsal aorta, scRNAseq and live-imaging of mitophagy-reporter zebrafish indicate that mitophagy initiates during endothelial-to-hematopoietic transition and colonization of secondary niches. Knockdown of bnip3lb reduces mitophagy and HSPC numbers in the caudal hematopoietic tissue by promoting myeloid-biased differentiation and apoptosis, which can be rescued by antioxidant exposure. Conversely, chemical or genetic induction of mitophagy enhances embryonic HSPC and lymphoid progenitor numbers. Significantly, compound-mediated mitophagy activation improves ex vivo function of HSPCs derived from human-induced pluripotent stem cells, enhancing serial-replating hematopoietic colony forming potential.
    DOI:  https://doi.org/10.1038/s41467-026-69593-9
  44. bioRxiv. 2026 Feb 18. pii: 2026.02.12.705660. [Epub ahead of print]
      Somatic mutations in mitochondrial DNA (mtDNA) provide natural barcodes that enable engineering-free lineage tracing in human tissues, but the complex dynamics of mtDNA inheritance across cell divisions and incomplete sampling of mtDNA introduce uncertainty in reconstructed lineages. Here, we present MitoDrift, a probabilistic framework that integrates Wright-Fisher drift dynamics with sparse single-cell measurements to produce confidence-refined lineage trees enriched for accurate clonal relationships. Validation with gold-standard lentiviral barcoding and whole-genome sequencing demonstrates that MitoDrift outperforms existing tree reconstruction methods in precision while maintaining high clonal recovery, enabling robust analyses linking lineage to cell state. Applying MitoDrift to human hematopoiesis reveals an age-associated decline in clonal diversity with differential impact across cell types and identifies heritable regulatory programs in hematopoietic stem cells in vivo, linking AP-1/stress-associated programs to clonal expansions. In multiple myeloma, MitoDrift captures therapy-associated clonal remodeling undetectable by copy number analysis, revealing phenotypic transitions and linking gene regulatory programs to differential drug sensitivity. Collectively, MitoDrift enables high-precision lineage tracing at scale and establishes quantitative lineage-state analysis in primary human tissues, linking clonal history to transcriptional and epigenetic programs in tissue homeostasis, aging, and disease.
    DOI:  https://doi.org/10.64898/2026.02.12.705660
  45. J Clin Invest. 2026 Feb 25. pii: e198708. [Epub ahead of print]
      Aortic aneurysms are age-linked aortic dilations that progress silently and carry high rupture mortality. Immune cells are recognized drivers of aneurysm pathogenesis. Clonal hematopoiesis is an age-related expansion of somatically mutated hematopoietic stem cells that reshapes immune function and contributes to diverse age-associated diseases. However, its contribution to aneurysm pathogenesis remains unclear. In this study, targeted ultradeep sequencing of patient specimens revealed a high prevalence of clonal hematopoiesis-associated mutations that correlated with faster aneurysm expansion. Thus, we modeled clonal hematopoiesis by competitively transplanting Tet2-deficient bone marrow into ApoE-knockout mice and induced aneurysms with angiotensin II. Tet2-clonal hematopoiesis mice developed significantly greater aortic dilation than controls. Interestingly, Tet2-deficient macrophages adopted an ACP5-positive, osteoclast-like state and produced more MMP9. Both genetic and pharmacological inhibition of osteoclast-like differentiation suppressed the Tet2-mediated aneurysmal growth in vivo. Thus, Tet2-driven clonal hematopoiesis accelerates aortic aneurysm progression through MMP9-producing osteoclast-like macrophages and therefore represents a tractable therapeutic axis.
    Keywords:  Aging; Cardiology; Genetic risk factors; Hematopoietic stem cells; Macrophages; Vascular biology
    DOI:  https://doi.org/10.1172/JCI198708
  46. Nucleic Acids Res. 2026 Feb 24. pii: gkag165. [Epub ahead of print]54(5):
      Nucleophosmin (NPM1) is a nucleolar protein commonly mutated in ~30% of newly diagnosed acute myeloid leukemia (AML) cases. These mutations occur in the terminal exon of the NPM1 gene, affecting the C-terminal DNA-binding domain of the protein and causing its delocalization to the cytoplasm-a hallmark of NPM1-mutated AML. NPM1 shuttling to the nucleoplasm is tightly regulated by posttranslational modifications, such as phosphorylation of Ser254, Ser260, and Tyr271 of the DNA-binding domain. However, the structural mechanisms underlying this process remain unclear. In this work, we show that Ser-to-Asp (S254D-S260D) and Tyr-to-pCMF (para-carboxymethyl phenylalanine) (Y271pCMF) phosphomimetic mutations induce significant structural and dynamical rearrangements, as well as drastic modifications in electrostatic surface potential. These changes compromise recognition of a G-quadruplex sequence from the c-MYC promoter by reducing DNA-binding affinity, reshape histone capturing dynamics, and fade charge segregation in the histone-binding domain. Combination of such substitutions in a triple phosphomimetic variant (S254D-S260D-Y271pCMF) further destabilizes the domain's structure and triggers protein aggregation. Altogether, these findings suggest that phosphorylation of Ser254, Ser260, and Tyr271 of the C-end DNA-binding domain weakens both DNA affinity and charge block-driven liquid-liquid phase separation, offering a molecular explanation for the delocalization of NPM1 outside of the nucleolus.
    DOI:  https://doi.org/10.1093/nar/gkag165
  47. Blood. 2026 Feb 26. pii: blood.2025030823. [Epub ahead of print]
      Selection of a hematopoietic progenitor cell donor for allogeneic hematopoietic cell transplantation (allo HCT) is essential for treatment planning; however, the parameters that define an "optimal" donor in the modern era are not well defined. Historically, donor-recipient human leukocyte antigen (HLA) mismatching correlated strongly with risk for graft versus host disease (GVHD) and reduced survival. For this reason, donor selection was typically hierarchical: HLA matched related and unrelated donors were evaluated first, followed by HLA mismatched donors (or deferral of HCT altogether) in patients lacking an HLA matched donor. The advent of post-transplant cyclophosphamide (PTCy)-based GVHD prevention has changed this paradigm. Survival outcomes following HLA-mismatched donor HCT with PTCy, including from related haploidentical or HLA-mismatched unrelated donors, are not different than HLA matched donor recipients in recent clinical trials and retrospective studies. These encouraging results present a new challenge: In the PTCy era, how should donors be prioritized among the many potential sources available? Herein we review HLA and non-HLA parameters that inform donor selection and discuss approaches to increase donor availability. Case vignettes focusing on concepts that may be adapted to heterogenous clinical scenarios are presented.
    DOI:  https://doi.org/10.1182/blood.2025030823