bims-scepro 2025-04-06 papers

bims-scepro

Biomed News

on Stem cell proteostasis

Issue of 2025–04–06
27 papers selected by
William Grey, University of York

Sex differences in DNMT3A-mutant clonal hematopoiesis and the effects of estrogen.
Efficacy of a Novel BCL-xL Degrader, DT2216, in Preclinical Models of JAK2-mutated Post-MPN AML.
Protocol for optimizing culture conditions for ex vivo activation during CRISPR-Cas9 gene editing in human hematopoietic stem and progenitor cells.
Multilayered HIV-1 resistance in HSPCs through CCR5 Knockout and B cell secretion of HIV-inhibiting antibodies.
Ontogeny Dictates Oncogenic Potential, Lineage Hierarchy, and Therapy Response in Pediatric Leukemia.
Immune checkpoints regulate acute myeloid leukemia stem cells.
CircTADA2A stabilizes p53 via interacting with TRIM28 and suppresses the maintenance of FLT3-ITD acute myeloid leukemia.
Spatial proteomics of ER tubules reveals CLMN, an ER-actin tether at focal adhesions that promotes cell migration.
Epigenetic mechanisms controlling human leukemia stem cells and therapy resistance.
Global analysis of protein turnover dynamics in single cells.
C3G promotes bone marrow adipocyte expansion and hematopoietic regeneration after myeloablation by enhancing megakaryocyte niche function.
Enhancer hijacking discovery in acute myeloid leukemia by pyjacker identifies MNX1 activation via deletion 7q.
Novel Pan-ALDH Inhibitor KS100 Effectively Targets ALDH+/CD138⁻ Stem-like Cells to Overcome Relapse in Multiple Myeloma.
Decursin induces FLT3-ITD acute myeloid leukemia cell apoptosis by increasing the expression of the ubiquitin-conjugase UBE2L6.
CD34 serves as an intrinsic innate immune guardrail protecting stem cells from replicating retroviruses.
Modulation of bone marrow haematopoietic stem cell activity as a therapeutic strategy after myocardial infarction: a preclinical study.
Spindle integrity is regulated by a phospho-dependent interaction between the Ndc80 and Dam1 kinetochore complexes.
Cell-autonomous dysregulation of interferon signaling drives clonal expansion of SRSF2-mutant MDS stem/progenitor cells.
Transcription factor networks disproportionately enrich for heritability of blood cell phenotypes.
ATM-dependent DNA damage response constrains cell growth and drives clonal hematopoiesis in telomere biology disorders.
Efficient discrimination of functional hematopoietic stem cell progenitors for transplantation by combining alkaline phosphatase activity and CD34+ immunophenotyping.
Ex vivo Modification of Hematopoietic Stem and Progenitor Cells for Gene Therapy.
Fetal context conveys heritable protection against MLL-rearranged leukemia that depends on MLL3.
Structural mimicry of UM171 and neomorphic cancer mutants co-opts E3 ligase KBTBD4 for HDAC1/2 recruitment.
Severe inflammation and lineage skewing are associated with poor engraftment of engineered hematopoietic stem cells in patients with sickle cell disease.
H1-0 is a specific mediator of the repressive ETV6::RUNX1 transcriptional landscape in preleukemia and B cell acute lymphoblastic leukemia.
A niche driven mechanism determines response and a mutation-independent therapeutic approach for myeloid malignancies.

Cell Rep. 2025 Apr 02. pii: S2211-1247(25)00265-7. [Epub ahead of print]44(4): 115494

Sex differences in DNMT3A-mutant clonal hematopoiesis and the effects of estrogen.

Julia Stomper, Abhishek Niroula, Roger Belizaire, Marie McConkey, Tagore Sanketh Bandaru, Benjamin L Ebert.

  Blood cancers are generally more common in males, and the prevalence of most mutations that drive clonal hematopoiesis and myeloid malignancies is higher in males. In contrast, hematopoietic DNMT3A mutations are more common in females. Among ∼450,000 participants in the UK Biobank, the prevalence of DNMT3A mutations and copy-number abnormalities is higher in females than males. In a murine model, Dnmt3a-mutant hematopoietic stem cells (HSCs) from unperturbed female mice had increased stemness gene expression compared to male and wild-type (WT) mice. Estrogen regulates HSCs, and we found that Dnmt3a mutations maintain stemness in the setting of estrogen-induced proliferative stress. Dnmt3a-mutant myeloid cells outcompeted WT cells under chronic estrogen treatment, an effect that was dependent on cell-intrinsic estrogen receptor alpha activity. Our studies indicate that estrogen might contribute to the female predominance of DNMT3A-mutant clonal hematopoiesis.

Keywords:  CHIP; CP: Stem cell research; DNMT3A; Esr1; HSC; clonal hematopoiesis; estrogen; female; hormones; sex; stem cell

DOI:  https://doi.org/10.1016/j.celrep.2025.115494
Blood. 2025 Mar 31. pii: blood.2024027117. [Epub ahead of print]

Efficacy of a Novel BCL-xL Degrader, DT2216, in Preclinical Models of JAK2-mutated Post-MPN AML.

Zhe Wang, Anna Skwarska, Gowri Poigaialwar, Sovira Chaudhry, Alba Rodriguez-Meira, Pinpin Sui, Emmanuel Olivier, Yannan Jia, Varun Gupta, Warren Fiskus, Cassandra L Ramage, Guangrong Zheng, Alexandra Schurer, Kira Gritsman, Eirini P Papapetrou, Kapil N Bhalla, Daohong Zhou, Adam J Mead, Raajit K Rampal, Jeffrey W Tyner, Hussein A Abbas, Naveen Pemmaraju, Qi Zhang Tatarata, Marina Y Konopleva.

Acute myeloid leukemia (AML) that evolves from myeloproliferative neoplasm (MPN) is known as post-MPN AML. Current treatments don't significantly extend survival beyond 12 months. BCL-xL has been found to be overexpressed in leucocytes from MPN patients, making it a potential therapeutic target. We investigated the role of BCL-xL in post-MPN AML and tested the efficacy of DT2216, a platelet-sparing BCL-xL proteolysis-targeting chimera (PROTAC), in preclinical models of post-MPN AML. We found that BCL2L1, the gene encoding BCL-xL, is expressed at higher levels in post-MPN AML patients compared to those with de novo AML. Single-cell multi-omics analysis revealed that leukemia cells harboring both MPN-driver and TP53 mutations exhibited higher BCL2L1 expression, elevated scores for leukemia stem cell, megakaryocyte development, and erythroid progenitor than wild-type cells. BH3 profiling confirmed a strong dependence on BCL-xL in post-MPN AML cells. DT2216 alone, or in combination with standard AML/MPN therapies, effectively degraded BCL-xL, reduced the apoptotic threshold, and induced apoptosis in post-MPN AML cells. DT2216 effectively eliminated viable cells in JAK2-mutant AML cell lines, induced pluripotent stem cell-derived hematopoietic progenitor cells (iPSC-HPCs), primary samples, and reduced tumor burden in cell line-derived xenograft model in vivo by degrading BCL-xL. DT2216, either as a single agent or in combination with azacytidine, effectively inhibited the clonogenic potential of CD34+ leukemia cells from post-MPN AML patients. In summary, our data indicate that the survival of post-MPN AML is BCL-xL dependent, and DT2216 may offer therapeutic advantage in this high-risk leukemia subset with limited treatment options.

DOI: https://doi.org/10.1182/blood.2024027117
STAR Protoc. 2025 Mar 31. pii: S2666-1667(25)00128-5. [Epub ahead of print]6(2): 103722

Protocol for optimizing culture conditions for ex vivo activation during CRISPR-Cas9 gene editing in human hematopoietic stem and progenitor cells.

Lucrezia Della Volpe, Roberta Vacca, Raffaella Di Micco.

  Long-range correction strategies require ex vivo activation of hematopoietic stem and progenitor cells (HSPCs) to engage the homology-directed repair (HDR) mechanism, but prolonged culture causes harmful cellular responses, reducing the long-term functionality of gene-edited (GE) HSPCs. Here, we present a protocol for optimizing culture conditions for ex vivo activation during CRISPR-Cas9 gene editing in human HSPCs. We describe steps for HSPC thawing, ex vivo treatments, gene editing, and downstream in vitro and in vivo analyses to assess the functionality of GE-HSPCs. For complete details on the use and execution of this protocol, please refer to della Volpe et al.1.

Keywords:  CRISPR; Cell Biology; Cell culture; Stem Cells

DOI:  https://doi.org/10.1016/j.xpro.2025.103722
Nat Commun. 2025 Apr 01. 16(1): 3103

Multilayered HIV-1 resistance in HSPCs through CCR5 Knockout and B cell secretion of HIV-inhibiting antibodies.

William N Feist, Sofia E Luna, Kaya Ben-Efraim, Maria V Filsinger Interrante, Alvaro Amorin, Nicole M Johnston, Theodora U J Bruun, Ashley Utz, Hana Y Ghanim, Benjamin J Lesch, Theresa M McLaughlin, Amanda M Dudek, Matthew H Porteus.

Allogeneic transplantation of CCR5 null hematopoietic stem and progenitor cells (HSPCs) is the only known cure for HIV-1 infection. However, this treatment is limited because of the rarity of CCR5-null matched donors, the morbidities associated with allogeneic transplantation, and the prevalence of HIV-1 strains resistant to CCR5 knockout (KO) alone. Here, we propose a one-time therapy through autologous transplantation of HSPCs genetically engineered ex vivo to produce both CCR5 KO cells and long-term secretion of potent HIV-1 inhibiting antibodies from B cell progeny. CRISPR-Cas9-engineered HSPCs engraft and reconstitute multiple hematopoietic lineages in vivo and can be engineered to express multiple antibodies simultaneously (in pre-clinical models). Human B cells engineered to express each antibody secrete neutralizing concentrations capable of inhibiting HIV-1 pseudovirus infection in vitro. This work lays the foundation for a potential one-time functional cure for HIV-1 through combining the long-term delivery of therapeutic antibodies against HIV-1 and the known efficacy of CCR5 KO HSPC transplantation.

DOI: https://doi.org/10.1038/s41467-025-58371-8
bioRxiv. 2025 Mar 20. pii: 2025.03.19.643917. [Epub ahead of print]

Ontogeny Dictates Oncogenic Potential, Lineage Hierarchy, and Therapy Response in Pediatric Leukemia.

BDRL

Accumulating evidence links pediatric cancers to prenatal transformation events, yet the influence of the developmental stage on oncogenesis remains elusive. We investigated how hematopoietic stem cell developmental stages affect leukemic transformation, disease progression, and therapy response using a novel, humanized model of NUP98::NSD1-driven pediatric acute myeloid leukemia, that is particularly aggressive with WT1 co-mutations. Fetal-derived hematopoietic stem cells readily transform into leukemia, and WT1 mutations further enhance stemness and alter lineage hierarchy. In contrast, stem cells from later developmental stages become progressively resistant to transformation. Single-cell analyses revealed that fetal-origin leukemia stem cells exhibit greater quiescence and reliance on oxidative phosphorylation than their postnatal counterparts. These differences drive distinct therapeutic responses, despite identical oncogenic mutations. In patients, onco-fetal transcriptional programs correlate with worse outcomes. By targeting key vulnerabilities of fetal-origin leukemia cells, we identified combination therapies that significantly reduce aggressiveness, highlighting the critical role of ontogeny in pediatric cancer treatment.

DOI: https://doi.org/10.1101/2025.03.19.643917
Leukemia. 2025 Apr 02.

Immune checkpoints regulate acute myeloid leukemia stem cells.

Chantal Reinhardt, Adrian F Ochsenbein.

Acute myeloid leukemia stem cells (LSCs) express major histocompatibility complex (MHC) class I and II and many different immune checkpoint ligands and receptors, in which respect they resemble professional antigen-presenting cells. In addition, LSCs reside in the bone marrow (BM), a primary and secondary lymphoid organ, surrounded by immune cells. The function of these immune checkpoints (ICs) in the regulation of an anti-tumor immune response is well studied and IC inhibitors (ICIs) became a standard of care in many solid tumors. However, ICIs have very limited efficacy in AML. Nevertheless, the expression especially of immune activating ligands and receptors on LSCs is somewhat unexpected, since these cells have to evade protective immunity. Many ICs have been shown to mediate direct signaling in AML blasts and LSCs and thereby regulate self-renewal, differentiation and expansion of leukemic cells. Thus, the expression of ICs on the cell surface or their soluble forms often correlate with worse survival. In this review we summarize recent data on selected ICs of the immunoglobulin superfamily (IgSF) and the tumor necrosis factor receptor superfamily (TNFRSF) that have a documented role in the regulation of LSCs, independent of their immune regulatory role, and might become novel therapeutic targets.

DOI: https://doi.org/10.1038/s41375-025-02566-x
Leukemia. 2025 Apr 02.

CircTADA2A stabilizes p53 via interacting with TRIM28 and suppresses the maintenance of FLT3-ITD acute myeloid leukemia.

Ran Li, Xiaolu Wu, Kai Xue, Shishuang Wu, Ge Jiang, Mengke He, Yi Xia, Hailing Liu, Miao Zhong, Jianyong Li, Lei Fan, Junmin Li.

Internal tandem duplication mutations in the FMS-like tyrosine kinase 3 (FLT3-ITDs) occur in 25%-30% of acute myeloid leukemia (AML) cases and are associated with adverse prognosis. RNA-based therapeutics exhibit significant potential for treating diseases, prompting us to develop a novel circular RNA (circRNA)-based therapeutic strategy for FLT3-ITD AML. Here, we find circTADA2A is downregulated in FLT3-ITD AML patients. We further demonstrate that the downregulation of circTADA2A is critical for the proliferation of human FLT3-ITD AML cells, the sustenance of AML, and the self-renewal of leukemia stem/initiating cells (LSCs/LICs). Mechanistically, circTADA2A inhibits the TRIM28/MDM2 complexes formation by competitively binding to TRIM28, resulting in decreased levels of p53 ubiquitination and activating the p53 pathway. Importantly, in vitro transcription of circTADA2A and in vivo delivery via lipid nanoparticles (LNPs) significantly enhance the elimination of FLT3-ITD leukemia cells in combination with quizartinib treatment. In conclusion, our work uncovers the crucial functions of circTADA2A in the maintenance of FLT3-ITD AML and highlights a translationally important circTADA2A-based therapeutic approach for FLT3-ITD AML treatment.

DOI: https://doi.org/10.1038/s41375-025-02589-4
Cell Rep. 2025 Apr 03. pii: S2211-1247(25)00273-6. [Epub ahead of print]44(4): 115502

Spatial proteomics of ER tubules reveals CLMN, an ER-actin tether at focal adhesions that promotes cell migration.

Holly Merta, Kaitlynn Gov, Tadamoto Isogai, Blessy Paul, Achinta Sannigrahi, Arun Radhakrishnan, Gaudenz Danuser, W Mike Henne.

  The endoplasmic reticulum (ER) is structurally and functionally diverse, yet how its functions are organized within morphological subdomains is incompletely understood. Utilizing TurboID-based proximity labeling and CRISPR knockin technologies, we map the proteomic landscape of the human ER network. Sub-organelle proteomics reveals enrichments of proteins into ER tubules, sheets, and the nuclear envelope. We uncover an ER-enriched actin-binding protein, calmin/CLMN, and define it as an ER-actin tether that localizes to focal adhesions adjacent to ER tubules. Mechanistically, we find that CLMN depletion perturbs adhesion disassembly, actin dynamics, and cell movement. CLMN-depleted cells display decreased polarization of ER-plasma membrane contacts and calcium signaling factor STIM1 and altered calcium signaling near ER-actin interfaces, suggesting that CLMN influences calcium signaling to facilitate F-actin/adhesion dynamics. Collectively, we map the sub-organelle proteome landscape of the ER, identify CLMN as an ER-actin tether, and describe a non-canonical mechanism by which ER tubules engage actin to regulate cell migration.

Keywords:  CLMN; CP: Cell biology; ER; TurboID; adhesion; calmin; endoplasmic reticulum; migration

DOI:  https://doi.org/10.1016/j.celrep.2025.115502
Nat Commun. 2025 Apr 03. 16(1): 3196

Epigenetic mechanisms controlling human leukemia stem cells and therapy resistance.

Sumiko Takao, Victor Morell, Masahiro Uni, Alicia Slavit, Sophia Rha, Shuyuan Cheng, Laura K Schmalbrock, Fiona C Brown, Sergi Beneyto-Calabuig, Richard P Koche, Lars Velten, Alex Kentsis.

Cancer stem cells are essential for initiation and therapy resistance of many cancers, including acute myeloid leukemias (AML). Here, we apply functional genomic profiling to diverse human leukemias, including high-risk MLL- and NUP98-rearranged specimens, using label tracing in vivo. Human leukemia propagation is mediated by a rare quiescent label-retaining cell (LRC) population undetectable by current immunophenotypic markers. AML quiescence is reversible, preserving genetic clonal competition and epigenetic inheritance. LRC quiescence is defined by distinct promoter-centered chromatin and gene expression dynamics controlled by an AP-1/ETS transcription factor network, where JUN is necessary and sufficient for LRC quiescence and associated with persistence and chemotherapy resistance in diverse patients. This enables prospective isolation and manipulation of immunophenotypically-varied leukemia stem cells, establishing the functions of epigenetic plasticity in leukemia development and therapy resistance. These findings offer insights into leukemia stem cell quiescence and the design of therapeutic strategies for their clinical identification and control.

DOI: https://doi.org/10.1038/s41467-025-58370-9
Cell. 2025 Mar 26. pii: S0092-8674(25)00275-2. [Epub ahead of print]

Global analysis of protein turnover dynamics in single cells.

Pierre Sabatier, Maico Lechner, Ulises H Guzmán, Christian M Beusch, Xinlei Zeng, Longteng Wang, Fabiana Izaguirre, Anjali Seth, Olga Gritsenko, Sergey Rodin, Karl-Henrik Grinnemo, Zilu Ye, Jesper V Olsen.

  Single-cell proteomics (SCPs) has advanced significantly, yet it remains largely unidimensional, focusing primarily on protein abundances. In this study, we employed a pulsed stable isotope labeling by amino acids in cell culture (pSILAC) approach to simultaneously analyze protein abundance and turnover in single cells (SC-pSILAC). Using a state-of-the-art SCP workflow, we demonstrated that two SILAC labels are detectable from ∼4,000 proteins in single HeLa cells recapitulating known biology. We performed a large-scale time-series SC-pSILAC analysis of undirected differentiation of human induced pluripotent stem cells (iPSCs) encompassing 6 sampling times over 2 months and analyzed >1,000 cells. Protein turnover dynamics highlighted differentiation-specific co-regulation of protein complexes with core histone turnover, discriminating dividing and non-dividing cells. Lastly, correlating cell diameter with the abundance of individual proteins showed that histones and some cell-cycle proteins do not scale with cell size. The SC-pSILAC method provides a multidimensional view of protein dynamics in single-cell biology.

Keywords:  Chip-Tip; Evosep; Orbitrap Astral; cellenONE; histone; iPSC differentiation; mass spectrometry; protein turnover; pulsed SILAC; single-cell proteomics

DOI:  https://doi.org/10.1016/j.cell.2025.03.002
J Hematol Oncol. 2025 Apr 01. 18(1): 38

C3G promotes bone marrow adipocyte expansion and hematopoietic regeneration after myeloablation by enhancing megakaryocyte niche function.

Óscar Herranz, Pablo Berrocal, Carmen Sicilia-Navarro, Cristina Fernández-Infante, Luis Hernández-Cano, Almudena Porras, Carmen Guerrero.

  C3G, a Rap1 GEF, promotes megakaryopoiesis and platelet function. Using transgenic and knock-out mouse models targeting C3G in megakaryocytes, we investigated whether C3G also affects the niche function of megakaryocytes during bone marrow (BM) recovery after myeloablation induced by 5-fluorouracil (5-FU), or total body irradiation (TBI) followed by bone marrow transplantation. C3G promoted megakaryocyte maturation and platelet production during recovery, along with increased white and red blood cell counts and enhanced survival of female mice after repeated doses of 5-FU. Additionally, megakaryocytes favored adipocyte differentiation through a C3G-mediated mechanism, likely involving Fgf1. Changes in the number or behavior of BM megakaryocytes and adipocytes influenced the hematopoietic stem cell pool, with C3G promoting its bias towards the myeloid-megakaryocytic lineage in both 5-FU- and TBI-ablated models. Therefore, C3G could be a potential target in therapies aimed at enhancing hematopoiesis in patients undergoing chemotherapy and/or BM transplantation.

Keywords:  Adipocyte; Bone marrow niche; Chemotherapy; Hematopoietic stem cell; Megakaryocyte; Myeloablation; Rapgef1; Transplantation

DOI:  https://doi.org/10.1186/s13045-025-01687-1
Blood Cancer Discov. 2025 Mar 31.

Enhancer hijacking discovery in acute myeloid leukemia by pyjacker identifies MNX1 activation via deletion 7q.

Etienne Sollier, Anna Riedel, Umut H Toprak, Justyna A Wierzbinska, Dieter Weichenhan, Jan Philipp Schmid, Mariam Hakobyan, Aurore Touzart, Ekaterina Jahn, Binje Vick, Fiona Brown-Burke, Katherine Kelly, Simge Kelekci, Anastasija Pejkovska, Ashish Goyal, Marion Bähr, Kersten Breuer, Mei-Ju May Chen, Maria Llamazares-Prada, Mark Hartmann, Maximilian Schönung, Nadia Correia, Andreas Trumpp, Yomn Abdullah, Ursula Klingmüller, Sadaf S Mughal, Benedikt Brors, Frank Westermann, Elias Ulrich, Robert J Autry, Matthias Schlesner, Sebastian Vosberg, Tobias Herold, Philipp A Greif, Dietmar Pfeifer, Michael Lübbert, Thomas Fischer, Florian H Heidel, Gebhard Gebhard, Wencke Walter, Torsten Haferlach, Ann-Kathrin Eisfeld, Krzysztof Mrózek, Deedra Nicolet, Lars Bullinger, Leonie Smeenk, Claudia Erpelinck-Verschueren, Roger Mulet-Lazaro, Ruud Delwel, Aurélie Ernst, Michael Scherer, Pavlo Lutsik, Irmela Jeremias, Konstanze Döhner, Hartmut Döhner, Daniel B Lipka, Christoph Plass.

Acute myeloid leukemia with complex karyotype (ckAML) is characterized by high genomic complexity, including frequent TP53 mutations and chromothripsis. Genomic rearrangements that reposition active enhancers near proto-oncogenes, leading to their aberrant expression, have not been systematically investigated in AML. To facilitate the discovery of such "enhancer hijacking" events, we developed pyjacker, a computational tool, and applied it to 39 ckAML samples. Pyjacker identified several enhancer hijacking events in AML patient samples, including aberrant expression of motor neuron and pancreas homeobox 1 (MNX1), which can result from del(7)(q22q36) and is associated with hijacking of a CDK6 enhancer. MNX1 activation occurs in 1.4% of AML patients and shows significant co-occurrence with BCOR mutations. Through a xenograft mouse model, we demonstrated that MNX1 is required for leukemia cell fitness. Pyjacker is an easy-to-use, accurate, and broadly applicable tool for identifying consequences of genomic events driving tumorigenesis, especially when germline genomic data is missing.

DOI: https://doi.org/10.1158/2643-3230.BCD-24-0278
bioRxiv. 2025 Mar 10. pii: 2025.03.06.641909. [Epub ahead of print]

Novel Pan-ALDH Inhibitor KS100 Effectively Targets ALDH+/CD138⁻ Stem-like Cells to Overcome Relapse in Multiple Myeloma.

Robert Chitren, Krishne Gowda, Shantu Amin, Gavin P Robertson, Subash Jonnalagadda, Tulin Budak-Alpdogan, Manoj K Pandey.

Multiple myeloma (MM), a clonal plasma cell disorder is the second most frequent hematological malignancy in the United States. This malignancy is characterized by a series of symptoms such as bone lesions, hypercalcemia, renal failure, and anemia. The current clinical drugs in the market are successful in treating multiple myeloma patients into remission but does not address relapse where a more aggressive phenotype of the cancer remains untreatable. We hypothesize that a small subset of multiple myeloma stem-like cells (MMSLC's) that overexpress aldehyde dehydrogenases (ALDH + ) is the cause of the relapse. Overexpression of ALDH bolsters drug resistance via detoxification and stemness via the retinoic acid signaling pathway. The phenotype of MMSLC's is not yet known for certainty but there are a few well established markers such CD138 negative (CD138 neg ) cells that are known to overexpress ALDH. In this study, we target regular MM cells and bortezomib resistant ALDH + /CD138 neg MMSLC's with a novel, potent, pan-ALDH inhibitor, KS100. Here we report KS100 effectively lowered ALDH expression in regular and bortezomib resistant ALDH + /CD138 neg cells, MM cell viability as well as proteins associated with MMSLC's. Most importantly we showed that KS100 lowered ALDH + populations in regular, bortezomib resistant and CD138 neg cells via ALDEFLUOR™ assay.

DOI: https://doi.org/10.1101/2025.03.06.641909
Cell Commun Signal. 2025 Apr 02. 23(1): 162

Decursin induces FLT3-ITD acute myeloid leukemia cell apoptosis by increasing the expression of the ubiquitin-conjugase UBE2L6.

Tianxin Zhang, Yuchen Li, Wenhao Liao, Yu Mou, Xue Zhan, Qiongying Hu, Ziyi Zhao, Daqian Xiong.

  Mutation in the internal tandem duplication sequence of the FLT3 gene (FLT3-ITD) is linked to a poor clinical prognosis in acute myeloid leukemia (AML) patients. FLT3 inhibitors have demonstrated efficacy in improving the prognosis of AML patients with FLT3-ITD. However, the efficacy of FLT3 inhibitors is short-lived, and is often limited by secondary drug resistance when used alone. Recent investigations have provided an innovative approach for treating FLT3-ITD AML by targeting FLT3 protein degradation. Our study revealed that decursin selectively impaired the viability of FLT3-ITD-positive AML cells. Subsequent analysis revealed that decursin preferentially induced cell cycle arrest and apoptosis in FLT3-ITD-positive AML cells through proteasome-mediated FLT3-ITD degradation. Further research revealed that decursin significantly increased the expression of UBE2L6, an e2-conjugating enzyme that degrades FLT3-ITD. Downregulation of UBE2L6 by small hairpin RNA (shRNA) reduced decursin-induced FLT3-ITD-linked apoptosis and degradation. The anti-FLT3-ITD AML effect of decursin was also validated in cell lines and patient-derived mouse models. Moreover, decursin synergistically enhanced venetoclax-induced apoptosis.

Keywords:  AML; Decursin; Degradation; FLT3-ITD; UBE2L6

DOI:  https://doi.org/10.1186/s12964-025-02157-4
bioRxiv. 2025 Mar 17. pii: 2025.03.15.643450. [Epub ahead of print]

CD34 serves as an intrinsic innate immune guardrail protecting stem cells from replicating retroviruses.

Sijia He, Amrita Haikerwal, Sameer Tiwari, Deemah Dabbagh, Mohammed Z Alam, Janice L Yoon, Brian Hetrick, Yang Han, Liang Shan, Christopher Lockhart, Yuntao Wu.

Stem cells are highly resistant to viral infection compared to their differentiated progeny, and this resistance is associated with stem cell-specific restriction factors and intrinsic interferon stimulated genes (ISGs). In HIV infection, proviral DNA has been detected in certain bone marrow hematopoietic stem cells, yet widespread stem cell infection in vivo is restricted. Intriguingly, exposing bone marrow stem cells to HIV in vitro led to viral replication selectively only in the CD34 - population, but not in the CD34 + cells. The mechanism dictating this CD34-based HIV restriction remained a mystery, especially since HIV has a capacity to antagonize restriction factors and ISGs. CD34 is a common marker of hematopoietic stem and progenitor cells. Here, we report the intrinsic antiviral properties of CD34. Expression of CD34 in HIV-1 producer cells results in the loss of progeny virion infectivity. Conversely, removal of CD34 using CRISPR/Cas9 knockout or stem cell differentiation cytokines promotes HIV-1 replication in stem cells. These results suggest that in addition to restriction factors and intrinsic ISGs, CD34 serves as a host innate protection preventing retrovirus replication in stem cells. Mechanistically, CD34 does not block viral entry, integration, and release. Instead, it becomes incorporated onto progeny virions, which inactivates virus infectivity. These findings offer new insights into innate immunity in stem cells, and highlight intriguing retrovirus-host interactions in evolution.

DOI: https://doi.org/10.1101/2025.03.15.643450
Nat Cell Biol. 2025 Apr 02.

Modulation of bone marrow haematopoietic stem cell activity as a therapeutic strategy after myocardial infarction: a preclinical study.

Jasmin Rettkowski, Mari Carmen Romero-Mulero, Indranil Singh, Carolin Wadle, Jan Wrobel, Diana Chiang, Natalie Hoppe, Julian Mess, Katharina Schönberger, Maria-Eleni Lalioti, Karin Jäcklein, Beatriz SilvaRego, Timon Bühler, Noémie Karabacz, Mirijam Egg, Helen Demollin, Nadine Obier, Yu Wei Zhang, Claus Jülicher, Anne Hetkamp, Martin Czerny, Michael-Jason Jones, Hana Seung, Ritika Jain, Constantin von Zur Mühlen, Alexander Maier, Achim Lother, Ingo Hilgendorf, Peter van Galen, Antonia Kreso, Dirk Westermann, Alejo E Rodriguez-Fraticelli, Timo Heidt, Nina Cabezas-Wallscheid.

Myocardial infarction (MI) is a major global health concern. Although myeloid cells are crucial for tissue repair in emergency haematopoiesis after MI, excessive myelopoiesis can exacerbate scarring and impair cardiac function. Bone marrow (BM) haematopoietic stem cells (HSCs) have the unique capability to replenish the haematopoietic system, but their role in emergency haematopoiesis after MI has not yet been established. Here we collected human sternal BM samples from over 150 cardiac surgery patients, selecting 49 with preserved cardiac function. We show that MI causes detrimental transcriptional and functional changes in human BM HSCs. Lineage tracing experiments suggest that HSCs are contributors of pro-inflammatory myeloid cells infiltrating cardiac tissue after MI. Therapeutically, enforcing HSC quiescence with the vitamin A metabolite 4-oxo-retinoic acid dampens inflammatory myelopoiesis, thereby modulating tissue remodelling and preserving long-term cardiac function after MI.

DOI: https://doi.org/10.1038/s41556-025-01639-4
PLoS Genet. 2025 Apr 04. 21(4): e1011645

Spindle integrity is regulated by a phospho-dependent interaction between the Ndc80 and Dam1 kinetochore complexes.

Christian R Nelson, Darren R Mallett, Sue Biggins.

Faithful chromosome segregation depends upon kinetochores, large protein complexes that anchor chromosomes to dynamic microtubules, allowing for their movement at anaphase. Critical microtubule-coupling components of the budding yeast kinetochore, the Dam1 (Dam1c) and Ndc80 (Ndc80c) complexes, work cooperatively to ensure that kinetochores track with the plus-ends of microtubules. Additionally, the Dam1 complex plays a distinct role in ensuring the integrity of the mitotic spindle. However, the events required to orchestrate these diverse functions of Dam1c remain unclear. To identify regulatory events on kinetochores, we performed phosphoproteomics on purified kinetochore proteins and identified many previously unknown phosphorylation events. We demonstrate that Ndc80 is phosphorylated at Thr-248 and Thr-252 to promote the interaction between Ndc80 and the Dam1c. The phosphorylation of T248 is cell cycle regulated and depends on Mps1. Ndc80 phosphorylation at T248 and T252 does not appear to regulate kinetochore function and instead contributes to Dam1c localization to the anaphase spindle. A ndc80 phospho-deficient mutant exhibited a genetic interaction and altered spindle morphology when combined with dam1 mutant alleles. Taken together, we propose that Mps1-dependent phosphorylation of Ndc80 at T248 and T252 is removed at anaphase to allow Dam1c to help organize and stabilize the spindle.

DOI: https://doi.org/10.1371/journal.pgen.1011645
Blood. 2025 Mar 31. pii: blood.2024025670. [Epub ahead of print]

Cell-autonomous dysregulation of interferon signaling drives clonal expansion of SRSF2-mutant MDS stem/progenitor cells.

Kouhei Takashima, Vrinda Jethalia, Maria Sirenko, Lewis R Silverman, Lewis Tomalin, Saul Carcamo, Dan Hasson, Eirini P Papapetrou.

Myelodysplastic syndromes (MDS) are myeloid malignancies often driven by mutations in genes encoding splicing factors (SFs). How these mutations drive the clonal expansion of MDS stem/progenitor cells to outcompete normal hematopoietic stem/progenitor cells (HSPCs) remains unexplained. Although a role for inflammatory processes in promoting clonal expansion of mutant HSPCs and MDS pathogenesis has been proposed, the specific mechanisms implicated remain incompletely understood. In this study, using human isogenic induced pluripotent stem cell (iPSC)-based models of SRSF2-mutant MDS and primary MDS patient cells, we show that the SRSF2 P95L mutation downregulates basal STAT1 expression. STAT1 downregulation dampens interferon (IFN) signaling in MDS stem/progenitor cells, which, unlike normal HSPCs, show resistance to suppression of clonogenic ability by IFNs. Treatment with the proteasome inhibitor bortezomib increased STAT1 protein levels and restored sensitivity of SRSF2-mutant cells to inflammatory stimuli. These results indicate that rewiring of STAT1 signaling by SRSF2 mutations blunts responsiveness to IFNs, conferring clonal fitness to SRSF2-mutant HSPCs against normal HSPCs in the presence of inflammatory stimuli. Our study provides a novel mechanistic link between SF mutations and inflammatory dysregulation and suggests proteasome inhibition as a potential strategy to treat MDS with SRSF2 mutations.

DOI: https://doi.org/10.1182/blood.2024025670
Science. 2025 Apr 04. 388(6742): 52-59

Transcription factor networks disproportionately enrich for heritability of blood cell phenotypes.

Jorge Diego Martin-Rufino, Alexis Caulier, Seayoung Lee, Nicole Castano, Emily King, Samantha Joubran, Marcus Jones, Seth R Goldman, Uma P Arora, Lara Wahlster, Eric S Lander, Vijay G Sankaran.

Most phenotype-associated genetic variants map to noncoding regulatory regions of the human genome, but their mechanisms remain elusive in most cases. We developed a highly efficient strategy, Perturb-multiome, to simultaneously profile chromatin accessibility and gene expression in single cells with CRISPR-mediated perturbation of master transcription factors (TFs). We examined the connection between TFs, accessible regions, and gene expression across the genome throughout hematopoietic differentiation. We discovered that variants within TF-sensitive accessible chromatin regions in erythroid differentiation, although representing <0.3% of the genome, show a ~100-fold enrichment for blood cell phenotype heritability, which is substantially higher than that for other accessible chromatin regions. Our approach facilitates large-scale mechanistic understanding of phenotype-associated genetic variants by connecting key cis-regulatory elements and their target genes within gene regulatory networks.

DOI: https://doi.org/10.1126/science.ads7951
J Clin Invest. 2025 Apr 03. pii: e181659. [Epub ahead of print]

ATM-dependent DNA damage response constrains cell growth and drives clonal hematopoiesis in telomere biology disorders.

Christopher M Sande, Stone Chen, Dana V Mitchell, Ping Lin, Diana M Abraham, Jessie M Cheng, Talia Gebhard, Rujul J Deolikar, Colby Freeman, Mary Zhou, Sushant Kumar, Michael Bowman, Robert L Bowman, Shannon Zheng, Bolormaa Munkhbileg, Qijun Chen, Natasha L Stanley, Kathy Guo, Ajibike Lapite, Ryan Hausler, Deanne M Taylor, James Corines, Jennifer Jd Morrissette, David B Lieberman, Guang Yang, Olga Shestova, Saar Gill, Jiayin Zheng, Kelcy Smith-Simmer, Lauren G Banaszak, Kyle N Shoger, Erica F Reinig, Madilynn Peterson, Peter Nicholas, Amanda J Walne, Inderjeet Dokal, Justin P Rosenheck, Karolyn A Oetjen, Daniel C Link, Andrew E Gelman, Christopher R Reilly, Ritika Dutta, R Coleman Lindsley, Karyn J Brundige, Suneet Agarwal, Alison A Bertuch, Jane E Churpek, Laneshia K Tague, F Brad Johnson, Timothy S Olson, Daria V Babushok.

  Telomere biology disorders (TBD) are genetic diseases caused by defective telomere maintenance. TBD patients often develop bone marrow failure and have an increased risk of myeloid neoplasms. To better understand the factors underlying hematopoietic outcomes in TBD, we comprehensively evaluated acquired genetic alterations in hematopoietic cells from 166 pediatric and adult TBD patients. 47.6% of patients (28.8% of children, 56.1% of adults) had clonal hematopoiesis. Recurrent somatic alterations involved telomere maintenance genes (7.6%), spliceosome genes (10.4%, mainly U2AF1 p.S34), and chromosomal alterations (20.2%), including 1q gain (5.9%). Somatic variants affecting the DNA damage response (DDR) were identified in 21.5% of patients, including 20 presumed loss-of-function variants in ATM. Using multimodal approaches, including single-cell sequencing, assays of ATM activation, telomere dysfunction-induced foci analysis, and cell growth assays, we demonstrate telomere dysfunction-induced activation of ATM-dependent DDR pathway with increased senescence and apoptosis in TBD patient cells. Pharmacologic ATM inhibition, modeling the effects of somatic ATM variants, selectively improved TBD cell fitness by allowing cells to bypass DDR-mediated senescence without detectably inducing chromosomal instability. Our results indicate that ATM-dependent DDR induced by telomere dysfunction is a key contributor to TBD pathogenesis and suggest dampening hyperactive ATM-dependent DDR as a potential therapeutic intervention.

Keywords:  Clonal selection; Hematology; Hematopoietic stem cells; Oncology; Telomeres

DOI:  https://doi.org/10.1172/JCI181659
Methods Cell Biol. 2025 ;pii: S0091-679X(23)00156-5. [Epub ahead of print]195 101-113

Efficient discrimination of functional hematopoietic stem cell progenitors for transplantation by combining alkaline phosphatase activity and CD34+ immunophenotyping.

Laura G Rico, Jordi Juncà, Roser Salvia, Michael D Ward, Jolene A Bradford, Jordi Petriz.

  Alkaline phosphatase (ALP) is a membrane-associated hydrolase enzyme with dimeric structure that catalyzes phosphate esters, optimally at alkaline pH. ALP has a focus of interest, since this enzyme is highly expressed in primitive stem cells, such as progenitor cells, non-differentiating cells, and primordial cells. We previously adapted a fluorescent microscopy-based assay for quantifying ALPhigh and ALPlow cells by flow cytometry in combination with immunophenotyping. Our method uses a minimal sample perturbation approach, avoiding the use of erythrocyte lysing solutions and washing steps, and offering opportunities to combine live cell response and functional assessment with cell immunophenotyping, while minimizing sample preparation effects on the cell biology. Here we provide a detailed experiment protocol to determine alkaline phosphatase activity in CD34+ hematopoietic stem cells from blood and apheresis products obtained from patients involved in a stem cell mobilization process for allo- or auto-transplant. This study may provide the early detection of progenitors at different levels of differentiation and therefore, relate this information to long-term engraftment in hematopoietic stem cell transplants.

Keywords:  Alkaline phosphatase; CD34; Flow cytometry; Graft; Stem cell transplantation

DOI:  https://doi.org/10.1016/bs.mcb.2023.08.003
Mol Ther. 2025 Apr 01. pii: S1525-0016(25)00267-9. [Epub ahead of print]

Ex vivo Modification of Hematopoietic Stem and Progenitor Cells for Gene Therapy.

David A Williams, Donald B Kohn, Adrian J Thrasher.

The development of viral vectors has been particularly critical for genetic therapies of hematologic diseases. Prior to the development of retrovirus vectors, gene transfer into mammalian cells was accomplished by transduction of DNA plasmids by chemical means and later by electroporation. The main limitation of these methods is the inefficiency of transfer of intact sequences, and particularly with electroporation significant cell death of the manipulated cells. The earliest successful human gene therapy trials utilized γ-RVV and many of the techniques developed in the 1980s. A breakthrough for the field was the exploitation and development of human immunodeficiency virus for transfer vectors, termed lentivirus vectors. In this review, we highlight uses of retro- and lentivirus vectors in monogenic diseases in which hematopoietic stem cells are used in the autologous setting to treat immunodeficiencies, hemoglobinopathies and metabolic diseases. The three authors' perspective represent experiences in the field over four decades that encompasses both basic translational research and development and oversight of early and ongoing gene therapy trials utilizing viral vectors.

DOI: https://doi.org/10.1016/j.ymthe.2025.03.058
bioRxiv. 2025 Mar 14. pii: 2025.03.11.642680. [Epub ahead of print]

Fetal context conveys heritable protection against MLL-rearranged leukemia that depends on MLL3.

Jonny Mendoza-Castrejon, Wei Yang, Elisabeth Denby, Helen Wang, Emily B Casey, Rohini Muthukumar, Riddhi M Patel, Jihye Yoon, Yanan Li, J Michael White, Ran Chen, Luis F Z Batista, Jeffrey A Magee.

MLL rearrangements ( MLL r) are the most common cause of congenital and infant leukemias. MLL r arise prior to birth and require few cooperating mutations for transformation, yet congenital leukemias are 10-fold less common than infant leukemias and >100-fold less common than childhood leukemias overall. This raises the question of whether mechanisms exist to suppress leukemic transformation during fetal life, thereby protecting the developing fetus from malignancy during a period of rapid hematopoietic progenitor expansion. Here, we use mouse models to show that fetal MLL::ENL exposure creates a heritable, leukemia-resistant state. MLL::ENL imposes a negative selective pressure on fetal hematopoietic progenitors. It leads to postnatal loss of self-renewal gene expression and enhanced myeloid differentiation that precludes transformation. These changes do not occur when MLL::ENL is induced shortly after birth, and transformation proceeds efficiently in this context. The fetal barrier to transformation is enforced by the histone methyltransferase MLL3. It can be overcome by cooperating mutations, such as Nras G12D , or through somatic or germline inactivation of MLL3. Heritable fetal protection against leukemic transformation may explain the low incidence of congenital leukemias in humans despite prenatal MLL rearrangement.

DOI: https://doi.org/10.1101/2025.03.11.642680
Nat Commun. 2025 Apr 02. 16(1): 3144

Structural mimicry of UM171 and neomorphic cancer mutants co-opts E3 ligase KBTBD4 for HDAC1/2 recruitment.

Zhuoyao Chen, Gamma Chi, Timea Balo, Xiangrong Chen, Beatriz Ralsi Montes, Steven C Clifford, Vincenzo D'Angiolella, Timea Szabo, Arpad Kiss, Tibor Novak, András Herner, András Kotschy, Alex N Bullock.

Neomorphic mutations and drugs can elicit unanticipated effects that require mechanistic understanding to inform clinical practice. Recurrent indel mutations in the Kelch domain of the KBTBD4 E3 ligase rewire epigenetic programs for stemness in medulloblastoma by recruiting LSD1-CoREST-HDAC1/2 complexes as neo-substrates for ubiquitination and degradation. UM171, an investigational drug for haematopoietic stem cell transplantation, was found to degrade LSD1-CoREST-HDAC1/2 complexes in a wild-type KBTBD4-dependent manner, suggesting a potential common mode of action. Here, we identify that these neomorphic interactions are mediated by the HDAC deacetylase domain. Cryo-EM studies of both wild-type and mutant KBTBD4 capture 2:1 and 2:2 KBTBD4-HDAC2 complexes, as well as a 2:1:1 KBTBD4-HDAC2-CoREST1 complex, at resolutions spanning 2.7 to 3.3 Å. The mutant and drug-induced complexes adopt similar structural assemblies requiring both Kelch domains in the KBTBD4 dimer for each HDAC2 interaction. UM171 is identified as a bona fide molecular glue binding across the ternary interface. Most strikingly, the indel mutation reshapes the same surface of KBTBD4 providing an example of a natural mimic of a molecular glue. Together, the structures provide mechanistic understanding of neomorphic KBTBD4, while structure-activity relationship (SAR) analysis of UM171 reveals analog S234984 as a more potent molecular glue for future studies.

DOI: https://doi.org/10.1038/s41467-025-58350-z
Nat Commun. 2025 Apr 01. 16(1): 3137

Severe inflammation and lineage skewing are associated with poor engraftment of engineered hematopoietic stem cells in patients with sickle cell disease.

Steicy Sobrino, Laure Joseph, Elisa Magrin, Anne Chalumeau, Nicolas Hebert, Alice Corsia, Adeline Denis, Cécile Roudaut, Clotilde Aussel, Olivia Leblanc, Mégane Brusson, Tristan Felix, Jean-Sebastien Diana, Angelina Petrichenko, Jana El Etri, Auria Godard, Eden Tibi, Sandra Manceau, Jean Marc Treluyer, Fulvio Mavilio, Frederic D Bushman, Ambroise Marcais, Martin Castelle, Benedicte Neven, Olivier Hermine, Sylvain Renolleau, Alessandra Magnani, Vahid Asnafi, Wassim El Nemer, Pablo Bartolucci, Emmanuelle Six, Michaela Semeraro, Annarita Miccio, Marina Cavazzana.

In sickle cell disease (SCD), the β6Glu→Val substitution in the β-globin leads to red blood cell sickling. The transplantation of autologous, genetically modified hematopoietic stem and progenitor cells (HSPCs) is a promising treatment option for patients with SCD. We completed a Phase I/II open-label clinical trial (NCT03964792) for patients with SCD using a lentiviral vector (DREPAGLOBE) expressing a potent anti-sickling β-globin. The primary endpoint was to evaluate the short-term safety and secondary endpoints included the efficacy and the long-term safety. We report on the results after 18 to 36 months of follow-up. No drug-related adverse events or signs of clonal hematopoiesis were observed. Despite similar vector copy numbers in the drug product, gene-marking in peripheral blood mononuclear cells and correction of the clinical phenotype varied from one patient to another. Single-cell transcriptome analyses show that in the patients with poor engraftment, the most immature HSCs display an exacerbated inflammatory signature (via IL-1 or TNF-α and interferon signaling pathways). This signature is accompanied by a lineage bias in the HSCs. Our clinical data indicates that the DREPAGLOBE-based gene therapy (GT) is safe. However, its efficacy is variable and probably depends on the number of infused HSCs and intrinsic, engraftment-impairing inflammatory alterations in HSCs. Trial: NCT03964792.

DOI: https://doi.org/10.1038/s41467-025-58321-4
Hemasphere. 2025 Apr;9(4): e70116

H1-0 is a specific mediator of the repressive ETV6::RUNX1 transcriptional landscape in preleukemia and B cell acute lymphoblastic leukemia.

Vera H Jepsen, Andrea Hanel, Daniel Picard, Rigveda Bhave, Rebecca Hasselmann, Juha Mehtonen, Julian Schliehe-Diecks, Carla-Johanna Kath, Vithusan Suppiyar, Yash Prasad, Katerina Schaal, Jia-Wey Tu, Nadine Rüchel, Ersen Kameri, Nan Qin, Herui Wang, Zhengping Zhuang, Rabea Wagener, Lena Blümel, Tobias Lautwein, Daniel Hein, David Koppstein, Gesine Kögler, Marc Remke, Sanil Bhatia, Merja Heinäniemi, Arndt Borkhardt, Ute Fischer.

ETV6::RUNX1, the most common oncogenic fusion in pediatric B cell precursor acute lymphoblastic leukemia (BCP-ALL), induces a clinically silent preleukemic state that can persist in carriers for over a decade and may progress to overt leukemia upon acquisition of secondary lesions. The mechanisms contributing to quiescence of ETV6::RUNX1+ preleukemic cells still remain elusive. In this study, we identify linker histone H1-0 as a critical mediator of the ETV6::RUNX1+ preleukemic state by employing human -induced pluripotent stem cell (hiPSC) models engineered by using CRISPR/Cas9 gene editing. Global gene expression analysis revealed upregulation of H1-0 in ETV6::RUNX1+ hiPSCs that was preserved upon hematopoietic differentiation. Moreover, whole transcriptome data of 1,727 leukemia patient samples showed significantly elevated H1-0 levels in ETV6::RUNX1+ BCP-ALL compared to other leukemia entities. Using dual-luciferase promoter assays, we show that ETV6::RUNX1 induces H1-0 promoter activity. We further demonstrate that depletion of H1-0 specifically inhibits ETV6::RUNX1 signature genes, including RAG1 and EPOR. Single-cell sequencing showed that H1-0 is highly expressed in quiescent hematopoietic cells. Importantly, H1-0 protein levels correspond to susceptibility of BCP-ALL cells towards histone deacetylase inhibitors (HDACis) and combinatorial treatment using the H1-0-inducing HDACi Quisinostat showed promising synergism with established chemotherapeutic drugs. Taken together, our data identify H1-0 as a key regulator of the ETV6::RUNX1+ transcriptome and indicate that the addition of Quisinostat may be beneficial to target non-responsive or relapsing ETV6::RUNX1+ BCP-ALL.

DOI: https://doi.org/10.1002/hem3.70116
Cancer Cell. 2025 Mar 20. pii: S1535-6108(25)00108-4. [Epub ahead of print]

A niche driven mechanism determines response and a mutation-independent therapeutic approach for myeloid malignancies.

Ioanna Mosialou, Abdullah M Ali, Rossella Labella, Brygida Bisikirska, Alvaro Cuesta-Dominguez, Paraskevi Vgenopoulou, Ismarc Reyes, Sanjana M Rao, Anqi Wang, Na Luo, Marta Galan-Diez, Junfei Zhao, Brian J Chernak, Jan Philipp Bewersdorf, Kazuya Fukasawa, Jiayu Su, Jason Higa, Rachel A Adams, Adam L Corper, Sergey Pampou, Catherine M Woods, Xiaomin Fan, Roshan P Shah, Julie Feldstein, Na Liu, Cui Liang, Maël Heiblig, Steven Kornblau, Guillermo Garcia-Manero, Ellin Berman, Joseph G Jurcic, Raul Rabadan, Azra Raza, Stavroula Kousteni.

  Myeloid cancers such as myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) remain resistant to standard of care (SOC) and targeted therapies. In this study, we demonstrate that responsiveness to therapy is associated with activation of β-catenin-JAG1 in osteoblastic cells of patients treated with all-trans-retinoic acid (ATRA). ATRA suppresses β-catenin activity in patients and leukemic mice. Consequently, it inhibits the growth and survival of MDS/AML cells from patients with active β-catenin-JAG1 signaling and promotes their differentiation. This occurs independently of cytogenetics and mutational profile. ATRA also improves disease outcome in mice with no evidence of relapse and a superior safety profile to SOC. A human anti-JAG1 antibody improves efficacy in leukemic mice and patient-derived MDS/AML cells. β-catenin activation provides an explanation for the differential response to ATRA and a mechanistic biomarker for ATRA repurposing in myeloid malignancies, potentially evading relapse and extending across a broad range of cancers.

Keywords:  AML; ATRA; MDS; anti-JAGGED1; b-catenin; bone marrow microenvironment; humanized antibody; myeloid malignancies; therapy

DOI:  https://doi.org/10.1016/j.ccell.2025.03.007