Hypodiploid and BCR::ABL1+ B-cell precursor acute lymphoblastic leukemia (BCP-ALL) confers a high risk of disease relapse. We investigated post-hematopoietic stem cell transplantation (HSCT) outcomes within the prospective FORUM trial, comparing outcomes among these genetic subgroups with those of patients without these lesions. The use of pre- and post-HSCT add-on treatments, including tyrosine kinase inhibitors (TKI) and immunotherapies, was also assessed. Multivariate analysis evaluated associations with overall survival (OS), event-free survival (EFS), and cumulative incidence of relapse (CIR). The FORUM trial enrolled 741 patients aged ≥4 years with BCP-ALL who underwent HSCT from HLA-matched donors (2013-2023). The 3-year OS and EFS did not differ significantly between patients with BCR::ABL1 fusion, hypodiploidy, and neither of these 2 genetic lesions. However, patients with hypodiploid BCP-ALL in second complete remission (CR2) showed inferior OS and EFS, driven by higher nonrelapse mortality (NRM), which occurred exclusively in near-diploid cases. No NRM occurred in severe hypodiploid cases conditioned with total body irradiation. Minimal residual disease (MRD) positivity at transplant predicted worse OS, EFS, and CIR in all genetic groups. Patients with hypodiploid BCP-ALL were difficult to salvage after relapse, even with chimeric antigen receptor T-cell therapy. By contrast, BCR::ABL1+ patients had favorable outcomes, even when MRD positive before HSCT. Prophylactic TKI use after HSCT improved EFS and reduced CIR. BCR::ABL1+ patients who received a transplant in CR2 had a 3-year OS of 96%. In conclusion, the standardized FORUM protocol yielded comparable outcomes across genetic subgroups. Posttransplant TKI maintenance improved outcomes in BCR::ABL1+ BCP-ALL. This trial was registered at www.clinicaltrials.gov as #NCT01949129 and at www.clinicaltrialsregister.eu as #EudraCT2012-0032-22.

Patients with acute myeloid leukemia (AML) have a poor 5-year survival rate, highlighting the need for the identification of new approaches to target this disease. AML is highly dependent on glutathione (GSH) metabolism for survival. Although the metabolic role of GSH is well characterized in AML, the contribution of protein glutathionylation, a reversible modification that protects protein thiols from oxidative damage, remains largely unexplored. Therefore, we sought to elucidate the role of protein glutathionylation in AML pathogenesis. Here, we demonstrate that protein glutathionylation is essential for AML cell survival. Specifically, the loss of glutaredoxin 2 (GLRX2), an enzyme that removes GSH modifications, resulted in selective primary AML cell death while sparing normal human hematopoietic stem and progenitor cells. Unbiased proteomic analysis revealed increased mitochondrial protein glutathionylation upon GLRX2 depletion, accompanied by mitochondrial dysfunction, including impaired oxidative phosphorylation, reduced mitochondrial membrane potential, and increased opening of the mitochondrial permeability transition pore (mPTP). Further investigation identified adenosine triphosphate synthase subunit O (ATP5PO), a key regulator of mPTP opening and a component of the ATP synthase complex, as a critical GLRX2 target. Disruption of ATP5PO glutathionylation partially restored mPTP function and rescued AML cell viability after GLRX2 depletion. Moreover, both genetic and pharmacological inhibition of mPTP opening restored the leukemic potential of primary AML specimens in the absence of GLRX2. By disrupting glutathionylation-dependent mitochondrial homeostasis, this study reveals a novel vulnerability in AML that could inform future therapeutic strategies.

The regulation of the switch from fetal (HBG) to adult (HBB and HBD) β-globin gene expression has served as a paradigm for clinically relevant developmental transcriptional control. Mechanistic studies of this switch have predominantly focused on HBG repressors, with comparatively little attention paid to potential HBG activators. We found that in adult-type HUDEP2 erythroid cells, the ATP-dependent chromatin remodeler Brahma Related Gene 1 (BRG1) preferentially activates the HBG genes as well as the minor adult HBD gene. BRG1 is a core catalytic subunit of 3 BRG1/BRM-associated factor (BAF) complexes, canonical BAF, polybromo BAF, and noncanonical BAF (ncBAF) that regulate chromatin accessibility in distinct gene- and cell-type contexts. To dissect the specific BAF complex configuration mediating selective activation of HBG and HBD in erythroid cells, we performed CRISPR-mediated targeting of individual subunits and pinpointed the regulatory activity to the ncBAF complex. Loss of the ncBAF complex subunits BRD9 and BAF60A preferentially decreased HBG and HBD transcription while accelerating terminal erythroid differentiation and hemoglobinization. Acute pharmacological depletion of BRD9 in HUDEP2 and primary erythroid cells selectively reduced transcription of HBD and HBG, suggesting direct effects at these genes. Collectively, our unexpected findings demonstrate that the BAF complex, through distinct subcomplex configurations, can regulate selective gene expression within a multigene cluster. This expands the traditional view of BAF as a general coactivator, highlights its role in gene-specific regulation, and identifies a potential target for therapeutic manipulation of β-like globin genes in erythroid cell disorders.

We compared daunorubicin/cytarabine plus fractionated gemtuzumab ozogamicin (DAGO2) with CPX-351 (CPX; 1:2 randomization) in 439 patients with acute myeloid leukemia (AML) aged ≥60 years (median age, 68 years) without known adverse-risk cytogenetics. Median follow-up was 35 months. Patients not in measurable residual disease (MRD)-negative remission after course 1 could enter a second randomization between standard and intensified chemotherapy. Post-course 1, the overall response rate (complete remission [CR] + CR with incomplete hematological recovery) was greater after DAGO2 (60% vs 47.5%; odds ratio [OR], 0.61; P = .016). Following course 2, the overall response was not significantly different (85% for DAGO2 vs 78% for CPX; P = .095). More patients attained CR with MRD negativity after course 1 in the DAGO2 arm (47% vs 29% for CPX; OR, 0.46; P = .004). We observed better 3-year event-free survival (34% vs 27%; hazard ratio [HR], 0.73; P = .012) and overall survival (52% vs 35%; HR, 0.62; P = .001) with DAGO2. CPX did not provide a survival benefit in patients with myelodysplasia (MDS)-related mutations and was associated with poorer survival in patients with NPM1 (HR, 2.83) and FLT3 mutations (HR, 2.14). Overall, 37% of patients underwent transplantation in first remission, with no difference in transplantation frequency or survival after transplant between randomization groups. Among patients entering the course 2 randomization (n = 107), survival was equivalent between standard and intensified CPX doses (P = .565). In conclusion, in this population of older patients with AML without known adverse-risk cytogenetics, DAGO2 resulted in superior survival compared with CPX. CPX did not benefit patients with MDS-related mutations over DAGO2. This trial was registered at www.ClinicalTrials.gov as #NCT02272478.

Only 30% to 50% of patients with immune thrombocytopenia (ITP) exhibit a sustained response upon thrombopoietin receptor agonists (TPO-RA) withdrawal, underscoring the necessity for mechanistic elucidation. We enrolled 49 patients treated with TPO-RA for 4 months and performed a follow-up study for 3 months, classifying them into sustained responders (n = 21), and nonsustained responders (n = 28). Compared with total transforming growth factor β1 (TGF-β1) levels, activated TGF-β1 levels (3854 ± 4380 vs 943 ± 1500 pg/mL; P< .001) were significantly elevated in sustained responders, with integrin αvβ8 regulating TGF-β1 activation and restoring immune tolerance. We established a passive ITP model using platelet factor 4-TGF-β1 conditional knockout (CKO) mice, which exhibited a shorter duration of sustained response than wild-type (WT) mice. CKO mice demonstrated a reduced regulatory T-cell (Treg) population, an increased M1-to-M2 macrophage ratio, and more severe megakaryocyte destruction after anti-CD41 injection. Exogenous administration of αvβ8 (250 ng/kg) effectively activated TGF-β1 and prolonged remission after TPO discontinuation in WT mice. Additionally, CD4+ T cells were transfected with lentiviral small interfering RNA or short hairpin RNA to modulate integrin β8 expression and these were injected into severe combined immunodeficiency mice undergoing an active model of ITP. Results showed that β8 overexpression increased Tregs and reduced megakaryocyte damage. Mechanistically, TPO-RA modulated αvβ8-mediated TGF-β1 activation through the activator protein 1family and Smad family member 2 signaling pathways. Furthermore, D-mannose combined with TPO prolonged the response in ITP mice by upregulating αvβ8 and activating TGF-β1. Overall, the integrin αvβ8-mediated activation of TGF-β1 pathway represents a promising therapeutic target for ITP, with substantial potential for clinical application.