bims-scepro 2025-03-16 papers

bims-scepro

Biomed News

on Stem cell proteostasis

Issue of 2025–03–16
23 papers selected by
William Grey, University of York

TET2 deficiency increases the competitive advantage of hematopoietic stem and progenitor cells through upregulation of thrombopoietin receptor signaling.
Enforcement of stem-cell dormancy by nucleophosmin mutation is a critical determinant of unrestricted self-renewal during myeloid leukemogenesis.
Continuous map of early hematopoietic stem cell differentiation across human lifetime.
Periarteriolar niches become inflamed in aging bone marrow, remodeling the stromal microenvironment and depleting lymphoid progenitors.
Loss of Socs2 improves molecular responses to IFNα in a mouse model of myeloproliferative neoplasms driven by JAK2-V617F.
Leukemogenic Kras mutation reprograms multipotent progenitors to facilitate its spread through the hematopoietic system.
Clonal Hematopoiesis Landscape in Frequent Blood Donors.
Advantages and challenges of ex vivo generation and expansion of human hematopoietic stem cells from pluripotent stem cells.
Perinatal Nicotine Exposure Disrupts Hematopoietic Stem Cell Development and Elevates Influenza Susceptibility in Adulthood.
Phosphoproteomics identifies determinants of PAK inhibitor sensitivity in leukaemia cells.
Targeting KPNB1 suppresses AML cells by inhibiting HMGB2 nuclear import.
CCRL2 promotes the interferon-γ signaling response in myeloid neoplasms with erythroid differentiation and mutated TP53.
Pathway Coessentiality Mapping Reveals Complex II is Required for de novo Purine Biosynthesis in Acute Myeloid Leukemia.
Decoding the ontogeny of myeloid lineage diversity by cross-species and developmental analyses of hematopoietic progenitor atlases.
Efficient large-scale expansion of cord blood-derived NK cells: leveraging lipopolysaccharide for enhanced NK cell production.
A torpor-like state in mice slows blood epigenetic aging and prolongs healthspan.
Co-culture of multiple myeloma cell lines and bone marrow mesenchymal stem cells in a 3D microgel environment.
SMYD3 Activates Fatty Acid β-oxidation to Promote Self-Renewal of Leukemia Stem Cells.
The mitochondrial protease ClpP is a promising target for multiple myeloma treatment.
Profilin 1 induces drug resistance by downregulating CD138 expression via autophagy in multiple myeloma.
PSPC1 bridges cancer stemness and malignancy in acute myeloid leukemia.
RBM15-MKL1 fusion protein promotes leukemia via m6A methylation and WNT pathway activation.
Oncogenic and microenvironmental signals drive cell type specific apoptosis resistance in juvenile myelomonocytic leukemia.

Nat Commun. 2025 Mar 10. 16(1): 2384

TET2 deficiency increases the competitive advantage of hematopoietic stem and progenitor cells through upregulation of thrombopoietin receptor signaling.

Yitong Yang, Severine Cathelin, Alex C H Liu, Amit Subedi, Abdula Maher, Mohsen Hosseini, Dhanoop Manikoth Ayyathan, Robert Vanner, Steven M Chan.

Ten-Eleven Translocation-2 (TET2) mutations drive the expansion of mutant hematopoietic stem cells (HSCs) in clonal hematopoiesis (CH). However, the precise mechanisms by which TET2 mutations confer a competitive advantage to HSCs remain unclear. Here, through an epigenetic drug screen, we discover that inhibition of disruptor of telomeric silencing 1-like (DOT1L), a H3K79 methyltransferase, selectively reduces the fitness of Tet2 knockout (Tet2KO) hematopoietic stem and progenitor cells (HSPCs). Mechanistically, we find that TET2 deficiency increases H3K79 dimethylation and expression of Mpl, which encodes the thrombopoietin receptor (TPO-R). Correspondingly, TET2 deficiency is associated with a higher proportion of primitive Mpl-expressing (Mpl+) cells in the HSC compartment. Importantly, inhibition of Mpl expression or the signaling downstream of TPO-R is sufficient to reduce the competitive advantage of murine and human TET2-deficient HSPCs. Our findings demonstrate a critical role for aberrant TPO-R signaling in TET2 mutation-driven CH and uncover potential therapeutic strategies against this condition.

DOI: https://doi.org/10.1038/s41467-025-57614-y
Haematologica. 2025 Mar 13.

Enforcement of stem-cell dormancy by nucleophosmin mutation is a critical determinant of unrestricted self-renewal during myeloid leukemogenesis.

Maria Elena Boggio Merlo, Maria Mallardo, Lucilla Luzi, Giulia De Conti, Chiara Caprioli, Roman Hillje, Mario Faretta, Cecilia Restelli, Andrea Polazzi, Valentina Tabanelli, Angelica Calleri, Stefano Pileri, Pier Giuseppe Pelicci, Emanuela Colombo.

Mutations in the NPM1 gene (NPMc+) and in the FLT3 gene (FLT3-ITD) represent the most frequent co-occurring mutations in Acute Myeloid Leukemia (AML), yet the cellular and molecular mechanisms of their cooperation remain largely unexplored. Using mouse models that faithfully recapitulate human AML, we investigated the impact of these oncogenes on pre-leukemic and leukemic hematopoietic stem cells (HSCs), both separately and in combination. While both NPMc+ and Flt3-ITD promote the proliferation of pre-leukemia HSCs, only NPMc+ drives extended selfrenewal by preventing the depletion of the quiescent HSC pool. Quiescent HSCs exist in a dynamic equilibrium between dormant and active states, which respectively support self-renewal and regenerative haematopoiesis. Transcriptional profiling of these dormant and active states revealed that not only does NPMc+ stimulate the transition from dormancy to activity but it also reinforces the dormant state, thereby ensuring the replenishment of dormant HSCs. Intriguingly, the coexpression of NPMc+ and Flt3-ITD engenders a novel phenotypic state within quiescent HSCs, whereby dormancy and activity co-exist within a single cell. We posit that this unique state fuels the in vivo expansion of self-renewing HSCs and facilitates the rapid selection of leukemiainitiating cells. Pharmacological inhibition of the dormancy-related TGFβ1 - pathway effectively reduces the self-renewal capacity of leukemia SCs and extends survival in our mouse models. Collectively, these findings demonstrate that enforcement of HSC dormancy is a critical determinant of unrestricted self-renewal during leukemogenesis and, as such, represents a compelling target for the development of novel anti-leukemic therapies.

DOI: https://doi.org/10.3324/haematol.2024.286577
Nat Commun. 2025 Mar 07. 16(1): 2287

Continuous map of early hematopoietic stem cell differentiation across human lifetime.

Hana Komic, Tessa Schmachtel, Catia Simoes, Marius Külp, Weijia Yu, Adrien Jolly, Malin S Nilsson, Carmen Gonzalez, Felipe Prosper, Halvard Bonig, Bruno Paiva, Fredrik B Thorén, Michael A Rieger.

Uncovering early gene network changes of human hematopoietic stem cells (HSCs) leading to differentiation induction is of utmost importance for therapeutic manipulation. We employed single cell proteo-transcriptomic sequencing to FACS-enriched bone marrow hematopoietic stem and progenitor cells (HSPCs) from 15 healthy donors. Pseudotime analysis reveals four major differentiation trajectories, which remain consistent upon aging, with an early branching point into megakaryocyte-erythroid progenitors. However, young donors suggest a more productive differentiation from HSPCs to committed progenitors of all lineages. tradeSeq analysis depicts continuous changes in gene expression of HSPC-related genes (DLK1, ADGRG6), and provides a roadmap of gene expression at the earliest branching points. We identify CD273/PD-L2 to be highly expressed in a subfraction of immature multipotent HSPCs with enhanced quiescence. Functional experiments confirm the immune-modulatory function of CD273/PD-L2 on HSPCs in regulating T-cell activation and cytokine release. Here, we present a molecular map of early HSPC differentiation across human life.

DOI: https://doi.org/10.1038/s41467-025-57096-y
Proc Natl Acad Sci U S A. 2025 Mar 18. 122(11): e2412317122

Periarteriolar niches become inflamed in aging bone marrow, remodeling the stromal microenvironment and depleting lymphoid progenitors.

Liming Du, Maria Angelica Freitas-Cortez, Jingzhu Zhang, Yuanyuan Xue, Reshma T Veettil, Zhiyu Zhao, Sean J Morrison.

  In early postnatal and young adult bone marrow, Leptin receptor-expressing (LepR+) stromal cells and endothelial cells synthesize factors required for hematopoietic stem cell (HSC) maintenance, including Stem Cell Factor (SCF) and Cxcl12. However, little is known about how these stromal cells change during aging. We performed single-cell RNA sequencing of mouse bone marrow stromal cells at 2, 12, and 24 mo of age. We identified five transcriptionally distinct subsets of LepR+ cells, all of which expressed the highest levels of Scf and Cxcl12 in bone marrow throughout adult life. In aging bone marrow, SCF from LepR+ cells, but not endothelial cells, continued to be necessary for the maintenance of HSCs and early restricted progenitors. However, arteriolar endothelial cells and other periarteriolar cells expressed increasing levels of interferon during aging. This increased the numbers of periarteriolar Sca1+Cxcl9+LepR+ cells with an inflammatory gene signature and depleted lymphoid progenitors, at least some of which are also periarteriolar. The periarteriolar environment thus became particularly inflamed during aging, remodeling the stromal microenvironment and depleting lymphoid progenitors in an interferon-dependent manner.

Keywords:  hematopoietic stem cell; inflammation; interferon; lymphoid progenitor; niche

DOI:  https://doi.org/10.1073/pnas.2412317122
Leukemia. 2025 Mar 11.

Loss of Socs2 improves molecular responses to IFNα in a mouse model of myeloproliferative neoplasms driven by JAK2-V617F.

Marc Usart, Quentin Kimmerlin, Jan Stetka, Cédric Stoll, Shivam Rai, Tiago Almeida Fonseca, Riikka Karjalainen, Hui Hao-Shen, Julien Roux, Athimed El Taher, Dylan Lynch, Nikolai Makukhin, Alessio Ciulli, Radek C Skoda.

Therapy with pegylated interferon alpha (pegIFNα) can induce a deep molecular response in a subset of patients with myeloproliferative neoplasms (MPN). Here we investigated the role of Socs2, a negative regulator of cytokine signaling, in modulating the response to pegIFNα in a JAK2-V617F mouse model of MPN. Deleting Socs2 in JAK2-V617F mice resulted in increased sensitivity to cytokines, without causing significant alterations in the MPN phenotype. When subjected to pegIFNα, the loss of Socs2 enhanced the depletion of JAK2-mutant hematopoietic stem cells (HSCs), evidenced by reduced chimerism in peripheral blood and bone marrow compared to vehicle controls. Additionally, pegIFNα-treated Socs2-deficient JAK2-mutant HSCs exhibited functional impairments in secondary transplantations, reflecting long-term detrimental decline of their stemness. These findings demonstrate that loss of Socs2 enhances the effectiveness of pegIFNα in depleting the JAK2-mutant HSC clone. In line with the genetic ablation of Socs2, the SOCS2 inhibitor MN714 combined with IFNα exhibited better efficacy than IFNα alone in reducing the output of CD34+ cells from PV patients in vitro. Targeting SOCS2 could therefore improve therapeutic responsiveness in MPN patients receiving interferon therapy.

DOI: https://doi.org/10.1038/s41375-025-02550-5
J Exp Med. 2025 Jun 02. pii: e20240587. [Epub ahead of print]222(6):

Leukemogenic Kras mutation reprograms multipotent progenitors to facilitate its spread through the hematopoietic system.

Geunhyo Jang, Rosa Park, Eduardo Esteva, Pei-Feng Hsu, Jue Feng, Samik Upadhaya, Catherine M Sawai, Iannis Aifantis, David R Fooksman, Boris Reizis.

Leukemia-driving mutations are thought to arise in hematopoietic stem cells (HSC), yet the natural history of their spread is poorly understood. We genetically induced mutations within endogenous murine HSC and traced them in unmanipulated animals. In contrast to mutations associated with clonal hematopoiesis (such as Tet2 deletion), the leukemogenic KrasG12D mutation dramatically accelerated HSC contribution to all hematopoietic lineages. The acceleration was mediated by KrasG12D-expressing multipotent progenitors (MPP) that lacked self-renewal but showed increased proliferation and aberrant transcriptome. The deletion of osteopontin, a secreted negative regulator of stem/progenitor cells, delayed the early expansion of mutant progenitors. KrasG12D-carrying cells showed increased CXCR4-driven motility in the bone marrow, and the blockade of CXCR4 reduced the expansion of MPP in vivo. Finally, therapeutic blockade of KRASG12D spared mutant HSC but reduced the expansion of mutant MPP and their mature progeny. Thus, transforming mutations facilitate their own spread from stem cells by reprogramming MPP, creating a preleukemic state via a two-component stem/progenitor circuit.

DOI: https://doi.org/10.1084/jem.20240587
Blood. 2025 03 11. pii: blood.2024027999. [Epub ahead of print]

Clonal Hematopoiesis Landscape in Frequent Blood Donors.

Darja Karpova, Hector Huerga Encabo, Elisa Donato, Silvia Calderazzo, Michael Scherer, Miriam Llorian-Sopena, Aino-Maija Leppä, Roberto Würth, Patrick Stelmach, Despoina Papazoglou, Alessandra Ferrelli, Steven Ngo, Iuliia Kotova, Sabine Harenkamp, Kai Zimmer, Dominik Wolf, Jasper Panten, John Reed, Adriana Przybylla, Torsten Tonn, Annette Kopp-Schneider, Lars Velten, John F DiPersio, Terrence N Wong, Dominique Bonnet, Halvard Bonig, Andreas Trumpp.

Donor blood saves lives, yet the potential impact of recurrent large-volume phlebotomy on donor health and hematopoietic stem cells (HSCs) remains largely unexplored. In our study, we conducted a comprehensive screening of 217 older male volunteer donors with a history of extensive blood donation (>100 life-time donations) to investigate the phenomenon of clonal hematopoiesis (CH). No significant difference in the overall incidence of CH was found in frequent donors (FD) compared to sporadic donors (<10 life-time donations, 212 donors). However, upon deeper analysis of mutations in DNMT3A, the most commonly affected gene in CH, we observed distinct mutational patterns between the FD and age/sex matched control donor (CD) cohorts. Functional analysis of FD enriched DNMT3A variants examined in CRISPR-edited human HSCs demonstrated their competitive outgrowth potential upon stimulation with erythropoietin (EPO), a hormone which increases in response to blood loss. In contrast, clones harboring leukemogenic DNMT3A R882 mutations increase upon stimulation with IFNy. Through concurrent mutational and immunophenotypic profiling of primary samples at single cell resolution, a myeloid bias of premalignant R882 mutant HSCs was found, while no significant lineage bias was observed in HSCs harboring EPO responsive DNMT3A variants. The latter exhibited preferential erythroid differentiation when persistent erythropoietic stress was applied to CRISPR-edited human HSC xenografts. Our data demonstrate a nuanced ongoing Darwinian evolution at the somatic stem cell level, with EPO identified as a novel environmental factor that favors HSCs carrying certain DNMT3A mutations.

DOI: https://doi.org/10.1182/blood.2024027999
Exp Hematol. 2025 Mar 12. pii: S0301-472X(25)00043-8. [Epub ahead of print] 104752

Advantages and challenges of ex vivo generation and expansion of human hematopoietic stem cells from pluripotent stem cells.

Min Ding, Yu Lu, Quan-Kai Lei, Yun-Wen Zheng.

  Hematopoietic stem cell transplantation (HSCT) is an essential and increasing therapeutic approach for treating conditions such as leukemia, lymphoma, and other blood cancers. However, its widespread use faces significant challenges, including limited donor availability, pathogen, and the risk of immune rejection. The emergence of pluripotent stem cells (PSCs) offers a potential solution to these challenges. By enabling the generation of hematopoietic stem cell (HSCs) and blood cells in vitro, PSCs open pathways to address the limitations of traditional HSC sources. Self-induced or gene-edited PSCs from patients may provide an accessible and personalized option for clinical applications. In this review, we examine the current protocols for differentiating PSCs into HSCs and blood cells, highlighting their benefits and shortcomings. Despite advancements in this field, two primary challenges persist: low differentiation efficiency and difficulties in isolating and enriching functional HSCs. These problems make it difficult to obtain hematopoietic stem cells for long-term survival. Thus we propose innovative strategies and potential improvements including induction scheme optimization, reprogramming, and cell fate tracking. Future research should prioritize the development of efficient and reliable differentiation protocols for PSCs to obtain more functional HSCs. Additionally, establishing effective methods for enriching functional HSCs and blood cells will be critical for optimizing their use in clinical applications. These efforts hold the promise of overcoming current limitations and advancing the therapeutic potential of PSC-derived blood cells.

Keywords:  blood; graft-versus-host disease; hematopoietic stem cell; pluripotent stem cells

DOI:  https://doi.org/10.1016/j.exphem.2025.104752
bioRxiv. 2025 Feb 25. pii: 2025.02.23.639728. [Epub ahead of print]

Perinatal Nicotine Exposure Disrupts Hematopoietic Stem Cell Development and Elevates Influenza Susceptibility in Adulthood.

T Cool, A Rodriguez Y Baena, M Rommel, C Mattingly, E Bachinsky, S Saini, S Chattopadhyaya, Bryce A Manso, S Rajendiran, Atesh Worthington, D Poscablo, A Deguzman, T Berger-Cahn, David F Boyd, Camilla Forsberg.

Tobacco use during pregnancy has many deleterious health consequences for not only the smoking mother, but also on the unborn fetus. Children of smoking mothers are reported to have higher frequency and severity of respiratory diseases later in life; however, the mechanisms driving this increased vulnerability are not clearly understood. One potential cause of increased disease susceptibility is an altered immune system, originating in epigenetically maladaptive hematopoietic stem cells (HSCs). Here, we show that perinatal nicotine exposure (PNE) alters the establishment of HSCs and fetal-derived non-traditional tissue immune cells, with no alterations in circulating immune cell numbers. Suppression of HSCs and lung immune cells persisted for weeks after PNE had ceased. Strikingly, PNE led to increased disease susceptibility and severity upon challenge with influenza A virus in adulthood. This was associated with significant and highly selective alterations in lung immune cells, emphasizing the importance of cellular mechanisms in resilience to infections. Together, these experiments demonstrate that perinatal exposures that have deleterious consequences on hematopoietic establishment can impair immune function for life and identify the cellular mechanisms by which perinatal nicotine exposure predisposes the offspring to a weakened defense against respiratory pathogens.

DOI: https://doi.org/10.1101/2025.02.23.639728
Cell Commun Signal. 2025 Mar 13. 23(1): 135

Phosphoproteomics identifies determinants of PAK inhibitor sensitivity in leukaemia cells.

Pedro Casado, Santiago Marfa, Marym M Hadi, Henry Gerdes, Sandra M Martin-Guerrero, Farideh Miraki-Moud, Vinothini Rajeeve, Pedro R Cutillas.

   BACKGROUND: The P21 activated kinases (PAK) are frequently dysregulated in cancer and have central roles in oncogenic signalling, prompting the development of PAK inhibitors (PAKi) as anticancer agents. However, such compounds have not reached clinical use because, at least partially, there is a limited mechanistic understanding of their mode of action. Here, we aimed to characterize functional and molecular responses to PAKi (PF-3758309, FRAX-486 and IPA-3) in multiple acute myeloid leukaemia (AML) models to gain insights on the biochemical pathways affected by these inhibitors in this disease and identify determinants of response in patient samples.
METHODS: We mined phosphoproteomic datasets of primary AML, and used proteomics and phosphoproteomics to profile PAKi impact in immortalized (P31/Fuj and MV4-11), and primary AML cells from 8 AML patients. These omics datasets were integrated with gene dependency data to identify which proteins targeted by PAKi are necessary for the proliferation of AML. We studied the effect PAKi on cell cycle progression, proliferation, differentiation and apoptosis. Finally, we used phosphoproteomics data as input for machine learning models that predicted ex vivo response in two independent datasets of primary AML cells (with 36 and 50 cases, respectively) to PF-3758309 and identify markers of response.
RESULTS: We found that PAK1 activation- measured from phosphoproteomics data- was predictive of poor prognosis in primary AML cases. PF-3758309 was the most effective PAKi in reducing proliferation and inducing apoptosis in AML cell lines. In cell lines and primary cells, PF-3758309 inhibited PAK, AMPK and PKCA activities, reduced c-MYC transcriptional activity and the expression of ribosomal proteins, and targeted the FLT3 pathway in FLT3-ITD mutated cells. In primary cells, PF-3758309 reduced STAT5 phosphorylation at Tyr699. Functionally, PF-3758309 reduced cell-growth, induced apoptosis, blocked cell cycle progression and promoted differentiation in a model-dependent manner. ML modelling accurately classified primary AML samples as sensitive or resistant to PF-3758309 ex vivo treatment, and highlighted PHF2 phosphorylation at Ser705 as a robust response biomarker.
CONCLUSIONS: In summary, our data define the proteomic, molecular and functional responses of primary and immortalised AML cells to PF-3758309 and suggest a route to personalise AML treatments based on PAK inhibitors.

Keywords:  Acute myeloid leukaemia biomarkers; Cancer; Kinase inhibitors; Lysine demethylase PHF2; Machine learning; PAK inhibitors; PF-3758309; Phosphoproteomics; Proteomics; Target therapy

DOI:  https://doi.org/10.1186/s12964-025-02107-0
Oncogene. 2025 Mar 13.

Targeting KPNB1 suppresses AML cells by inhibiting HMGB2 nuclear import.

Yuxin Xie, Runlong Zhao, Yingjiao Zheng, Yan Li, Feng Wu, Yufei Lei, Lei Li, Hanqing Zeng, Zhe Chen, Yu Hou.

Acute myeloid leukemia (AML) represents the most prevalent malignancy within the hematologic system, characterized by refractory relapses and a scarcity of effective treatment options. Karyopherin subunit beta-1 (KPNB1) is a member of karyopherin β family, mediating the nuclear import of its cargoes. In this study, we found that elevated expression levels of KPNB1 are associated with unfavorable outcomes in patients with AML. The knockdown of KPNB1 resulted in growth inhibition and apoptosis in AML cells. Additionally, pharmacological inhibition of KPNB1 using the specific inhibitor importazole (IPZ) significantly reduced tumor burden and prolonged survival in MLL-AF9-induced AML mice. Notably, the inhibition of KPNB1 by IPZ significantly enhanced the sensitivity of both AML cell lines and patient-derived cells to venetoclax in vitro and in xenograft mice models. At the molecular level, we identified an unrecognized cargo of KPNB1, high mobility group 2 (HMGB2), which plays a crucial role in DNA damage repair. Inhibition of KPNB1 resulted in impaired nuclear import of HMGB2, eventually leading to compromised DNA damage repair in AML cells. Overall, our findings elucidate the essential roles of KPNB1 in AML cells through the HMGB2-DNA damage repair axis and highlight a promising therapeutic target for AML intervention.

DOI: https://doi.org/10.1038/s41388-025-03340-0
bioRxiv. 2025 Feb 27. pii: 2025.02.21.639304. [Epub ahead of print]

CCRL2 promotes the interferon-γ signaling response in myeloid neoplasms with erythroid differentiation and mutated TP53.

Nour Sabiha Naji, Sergiu Pasca, Theodora Chatzilygeroudi, Pablo Toledano-Sanz, Joseph Rimando, Yashvi Hemani, Brandy Perkins, Xinghan Zeng, Conover Talbot, Bogdan Paun, Abdulmuez Abdulmalik, Chen Lossos, Tatianna R Boronina, Ilias Sinanidis, Panagiotis Tsakiroglou, Priyanka Fernandes, Christopher Esteb, Alexander J Ambinder, Robert N Cole, Rena Xian, Ivana Gojo, Suman Paul, Mark J Levis, Amy E DeZern, Leo Luznik, Styliani Karanika, Linda S Resar, Richard J Jones, Frederick Bunz, Lukasz Gondek, Marios Arvanitis, Theodoros Karantanos.

Patients with myeloid neoplasms with loss-of-function TP53 mutations and erythroid differentiation have poor outcomes, and a better understanding of disease biology is required. Upregulation of interferon-γ (IFN-γ) signaling has been associated with acute myeloid leukemia (AML) progression and chemotherapy resistance, but its drivers remain unclear. In this study, we found that the surface receptor C-C motif chemokine receptor-like 2 (CCRL2) is overexpressed in AML with erythroid differentiation and TP53 mutations compared to other AML subtypes and healthy hematopoietic cells. The knockout (KO) of CCRL2 suppressed erythroleukemia growth in vitro and in vivo . Further proteomics and transcriptomics analysis revealed IFN-γ signaling response as the top CCRL2-regulated pathway in erythroleukemia. Our mechanistic studies support direct CCRL2 driven IFN-γ signaling independent of exogenous IFN-γ, through phosphorylation of STAT1, via JAK2-dependent and independent mechanisms. CCRL2/IFN-γ signaling is upregulated in erythroid leukemias, and TP53 mutated AML without concurrent increase of IFN-γ secretion in the bone marrow microenvironment and is directly induced by TP53 KO. Finally, CCRL2/IFN-γ signaling is associated with the transformation of pre-leukemic single-hit TP53 clones to multi-hit TP53 mutated AML, increased resistance to venetoclax and worse survival in AML. Overall, our findings support that CCRL2 is an essential driver of cell-autonomous IFN-γ signaling response in myeloid neoplasms with erythroid differentiation and TP53 mutations and highlight CCRL2 as a relevant novel target for these neoplasms.
One Sentence Summary: CCRL2 is overexpressed in AML with loss-of-function TP53 mutations and erythroid differentiation and promotes IFN-γ signaling response via a cell-intrinsic mechanism.

DOI: https://doi.org/10.1101/2025.02.21.639304
bioRxiv. 2025 Mar 02. pii: 2025.02.26.640463. [Epub ahead of print]

Pathway Coessentiality Mapping Reveals Complex II is Required for de novo Purine Biosynthesis in Acute Myeloid Leukemia.

Amy E Stewart, Derek K Zachman, Pol Castellano-Escuder, Lois M Kelly, Ben Zolyomi, Michael D I Aiduk, Christopher D Delaney, Ian C Lock, Claudie Bosc, John Bradley, Shane T Killarney, Olga R Ilkayeva, Christopher B Newgard, Navdeep S Chandel, Alexandre Puissant, Kris C Wood, Matthew D Hirschey.

Understanding how cellular pathways interact is crucial for treating complex diseases like cancer, yet our ability to map these connections systematically remains limited. Individual gene-gene interaction studies have provided insights 1,2 , but they miss the emergent properties of pathways working together. To address this challenge, we developed a multi-gene approach to pathway mapping and applied it to CRISPR data from the Cancer Dependency Map 3 . Our analysis of the electron transport chain revealed certain blood cancers, including acute myeloid leukemia (AML), depend on an unexpected link between Complex II and purine metabolism. Through stable isotope metabolomic tracing, we found that Complex II directly supports de novo purine biosynthesis and exogenous purines rescue AML from Complex II inhibition. The mechanism involves a metabolic circuit where glutamine provides nitrogen to build the purine ring, producing glutamate that Complex II must oxidize to sustain purine synthesis. This connection translated to a metabolic vulnerability whereby increasing intracellular glutamate levels suppresses purine production and sensitizes AML to Complex II inhibition. In mouse models, targeting Complex II triggered rapid disease regression and extended survival in aggressive AML. The clinical relevance of this pathway emerged in human studies, where higher Complex II gene expression correlates with both resistance to mitochondria-targeted therapies and worse survival outcomes specifically in AML patients. These findings establish Complex II as a central regulator of de novo purine biosynthesis and identify it as a promising therapeutic target in AML.

DOI: https://doi.org/10.1101/2025.02.26.640463
Cell Rep. 2025 Mar 07. pii: S2211-1247(25)00177-9. [Epub ahead of print]44(3): 115406

Decoding the ontogeny of myeloid lineage diversity by cross-species and developmental analyses of hematopoietic progenitor atlases.

Sheng Pan, Haoyu Tang, Bingpeng Yao, Guoxiong Tian, Beibei Sun, Yangmingzi Hu, Yan Chen, Jiaqian Li, Xiao Xu, Chao Zhang, Songmin Ying.

  Myeloid cells play vital roles in homeostasis and immune responses in vertebrates, but the developmental pathway underlying their lineage diversity remains elusive. Here, we construct a single-cell transcriptional map of myeloid progenitors from mouse bone marrow and conduct cross-species and developmental analyses across human, monkey, mouse, and zebrafish. We uncover a conserved specification program separating the eosinophil-basophil-mast cell (EBM) lineage and neutrophil-monocyte (NM) lineage, reclassifying myeloid cells beyond the conventional granulocytic and monocytic framework. By generating Ikzf2-EGFP reporter mice, we identify IKZF2 as a priming marker for EBM lineage specification. Ikzf2-EGFP+ and Ikzf2-EGFP- granulocyte-monocyte progenitors (GMPs) exhibit distinct potential to generate EBM and NM lineages, and Ikzf2-EGFP expression robustly distinguishes their progenies. Additionally, we demonstrate that lineage specification emerges early during myelopoiesis. These findings provide a redefined perspective on myeloid lineage ontogeny, highlighting the conservation of lineage specification and offering insights into the understanding and therapeutic development of myelopoiesis.

Keywords:  CP: Genomics; CP: Stem cell research; HSPC; atlas; cross-species; development; differentiation; evolution; lineage specification; myeloid cells; myelopoiesis; single-cell

DOI:  https://doi.org/10.1016/j.celrep.2025.115406
Cytotherapy. 2025 Feb 24. pii: S1465-3249(25)00065-9. [Epub ahead of print]

Efficient large-scale expansion of cord blood-derived NK cells: leveraging lipopolysaccharide for enhanced NK cell production.

Hataiwan Kunkanjanawan, Sirilak Somredngan, Tanut Kunkanjanawan, Patompon Wongtrakoongate, Wannida Wongsakmanee, Veerapol Khemarangsan, Jun-Ichi Masuyama, Rangsun Parnpai.

  Growing research in the immunotherapy field has shed light on the adoptive cell transfer efficacy of ex vivo expanded natural killer (NK) cells in cancer treatment. In accordance with the advantages of using cord blood as a source of hematopoietic cells, this study aimed to establish a sustainable supply of NK cells by developing a simple method for expanding cord blood-derived NK (CBNK) cells without using feeders or cell-sorting processes. To achieve this aim, culture strategies that stimulate the proliferation of NK cells from hematopoietic stem and progenitor cells (HSPCs) would result in a high purity of CBNK cells. Here, we first compared the potential of lipopolysaccharide (LPS) and the Notch signaling agonist Yhhu-3792 to promote CBNK cell proliferation in cytokine-based conditions before applying these findings to a large-scale expansion platform. Overall, we reveal that the presence of LPS at 1 µg/mL during the first week of a 21-day expansion protocol resulted in an average total nucleated cell (TNC) count of 1.68 ± 2.92 × 1010, with 92.09 ± 3.47% of the expanded cells being NK cells (n = 5). All subsequent analyses demonstrated that the expanded CBNK cells produced by this procedure are phenotypically and functionally competent NK cells. Collectively, this study developed a simple cytokine-based and cell-sorting-free method for the large-scale expansion of CBNK cells.

Keywords:  Notch signaling agonist; adoptive cell therapy; cord blood-derived natural killer cells; large-scale expansion; lipopolysaccharide; natural killer cells

DOI:  https://doi.org/10.1016/j.jcyt.2025.02.006
Nat Aging. 2025 Mar 07.

A torpor-like state in mice slows blood epigenetic aging and prolongs healthspan.

Lorna Jayne, Aurora Lavin-Peter, Julian Roessler, Alexander Tyshkovskiy, Mateusz Antoszewski, Erika Ren, Aleksandar Markovski, Senmiao Sun, Hanqi Yao, Vijay G Sankaran, Vadim N Gladyshev, Robert T Brooke, Steve Horvath, Eric C Griffith, Sinisa Hrvatin.

Torpor and hibernation are extreme physiological adaptations of homeotherms associated with pro-longevity effects. Yet the underlying mechanisms of how torpor affects aging, and whether hypothermic and hypometabolic states can be induced to slow aging and increase healthspan, remain unknown. Here we demonstrate that the activity of a spatially defined neuronal population in the preoptic area, which has previously been identified as a torpor-regulating brain region, is sufficient to induce a torpor-like state (TLS) in mice. Prolonged induction of TLS slows epigenetic aging across multiple tissues and improves healthspan. We isolate the effects of decreased metabolic rate, long-term caloric restriction, and decreased core body temperature (Tb) on blood epigenetic aging and find that the decelerating effect of TLSs on aging is mediated by decreased Tb. Taken together, our findings provide novel mechanistic insight into the decelerating effects of torpor and hibernation on aging and support the growing body of evidence that Tb is an important mediator of the aging processes.

DOI: https://doi.org/10.1038/s43587-025-00830-4
Biomater Adv. 2025 Feb 28. pii: S2772-9508(25)00070-6. [Epub ahead of print]172 214243

Co-culture of multiple myeloma cell lines and bone marrow mesenchymal stem cells in a 3D microgel environment.

M Inmaculada García-Briega, Júlia Plá-Salom, Sandra Clara-Trujillo, Laia Tolosa, Lourdes Cordón, Amparo Sempere, José Luís Gómez Ribelles.

  This study reproduces the complex relationships between tumour plasma cells and their bone marrow microenvironment in multiple myeloma in vitro. These relationships are established both with other cells and with the extracellular matrix and are key factors in tumour progression, generating resistance to antitumour drugs in the cellular and non-cellular environments. This paper proposes a 3D microenvironment model designed to capture the main components of the multiple myeloma tumour microenvironment. Multiple myeloma cells (MMCs) were dispersed in a microgel medium formed by gel-textured microspheres. The proteins and polysaccharides considered important in the interaction of the MMCs with their non-cellular environment were successfully grafted onto the surface of the microspheres, while human mesenchymal stem cells (MSCs) were cultured in a pellet with non-functionalised microspheres. The MSCs pellet was placed in the well plate together with the microgel and the MMCs and orbitally shaken to maintain them in suspension. The viability, cell cycle and proliferation of the RPMI8226, MM1S and U266 multiple myeloma cell lines and the direct adhesion of MMCs to the MSC pellet were quantified. The results revealed that all three cell lines are able to grow satisfactorily. In addition, the normal behaviour of the MMCs is not modified in any of the culture conditions studied.

Keywords:  Bone marrow niche; Co-culture; Layer by layer; Mesenchymal stem cells; Microgel; Multiple myeloma; Tissue engineering

DOI:  https://doi.org/10.1016/j.bioadv.2025.214243
Cancer Res. 2025 Mar 13.

SMYD3 Activates Fatty Acid β-oxidation to Promote Self-Renewal of Leukemia Stem Cells.

Min Zhou, Zihao Wu, Fen Wei, Chen Duan, Xiaoying Lin, Waiyi Zou, Chang Liu, Jingxuan Pan, Yanli Jin.

The development of BCR-ABL tyrosine kinase inhibitors (TKIs) has revolutionized disease management of chronic myeloid leukemia (CML). However, the persistence of leukemia stem cells (LSCs) remains a major barrier to curing CML, highlighting the urgent need to identify the regulators supporting LSCs. In this study, we validated the critical role of the histone methyltransferase SET and MYND domain containing 3 (SMYD3) in the maintenance of LSCs in CML. SMYD3 was overexpressed in CML LSCs and enhanced the survival and self-renewal properties of human primary CD34+ CML cells. Loss of SMYD3 blocked leukemogenesis and impaired the self-renewal and disease reconstitution abilities of LSCs in mice without affecting normal hematopoiesis. SMYD3 stimulated fatty acid β-oxidation (FAO) in LSCs by activating the FABP5/PPARD/CPT1A signaling axis in a methyltransferase activity-dependent manner. Blocking CPT1A-mediated FAO reduced the function of human CML LSCs in vitro and depleted LSCs in vivo. These findings shed light on the role of histone lysine methylation-mediated FAO in the maintenance of LSCs and suggest that SMYD3 may serve as a therapeutic target for treating patients with CML.

DOI: https://doi.org/10.1158/0008-5472.CAN-24-2117
Biochem Pharmacol. 2025 Mar 05. pii: S0006-2952(25)00117-0. [Epub ahead of print] 116855

The mitochondrial protease ClpP is a promising target for multiple myeloma treatment.

Xiang Liu, Jinlong Gu, Song Liu, Jingcao Huang, Linfeng Li, Fangfang Wang, Siyao He, Ziyue Mi, Yue Zhang, Jingjing Wen, Qianwen Gao, Haonan Yang, Yu Feng, Hongmei Luo, Xinyu Zhai, Li Zhang, Yuhuan Zheng, Youfu Luo, Ting Niu.

  Drug resistance and relapse are the major obstacles in multiple myeloma (MM) treatment, driving the search for novel therapeutics. The chemoactivation of mitochondrial caseinolytic protease P (ClpP) has shown to have anticancer effects on many tumors, but has seldom been elucidated in MM. Here we found that the CLPP expression was elevated in MM patients, and further increased in relapsed cases. After synthesizing and screening a panel of ClpP agonists, we identified a compound, 7b, as the most potent anti-MM agent in vitro. 7b activated ClpP protease activity, selectively degrading mitochondrial proteins, many of which are involved in oxidative phosphorylation (OXPHOS). As result, 7b treated MM had metabolic dysfunction, the mitochondrial membrane potential (MMP) collapse, reduced OXPHOS levels, and increased mitochondrial reactive oxygen species (ROS), leading to mitophagy-mediated MM cell death. Notably, 7b also showed efficacy against drug-resistant MM cell lines, including bortezomib- and lenalidomide-resistant cells. In vivo, 7b also exhibited remarkable anti-MM activity with tolerable side effects. In conclusion, targeting ClpP represents a promising therapeutic strategy for MM, with 7b serving as a potent anti-MM agent, especially for relapsed and refractory MM.

Keywords:  ClpP; Mitochondria; Multiple myeloma; Oxidative phosphorylation

DOI:  https://doi.org/10.1016/j.bcp.2025.116855
Discov Oncol. 2025 Mar 08. 16(1): 284

Profilin 1 induces drug resistance by downregulating CD138 expression via autophagy in multiple myeloma.

Ya Wang, ZiYu Dai, Shengying Xiao, Furen Zeng, YiChen Lu.

Multiple myeloma (MM), a plasma cell-derived malignant hematological disease, is often treated with bortezomib, a highly effective first-generation proteasome inhibitor. However, resistance to bortezomib is a common occurrence. Profilin 1 (PFN1), a cytoskeleton-related gene known to promote autophagy in MM, induces this resistance to bortezomib, but it is unclear why. The aim of this study was to uncover the molecular mechanisms involved in bortezomib resistance, considering not only PFN1, but also CD138, a transmembrane proteoglycan that is a hallmark of plasma and MM cells. We detected CD138 and PFN1 in the bone marrow of patients with MM immunohistochemically. We also studied the Gene Expression Omnibus (GEO) data and found that CD138 was associated with PFN1 and autophagy. We then evaluated their expression in an MM cell line via western blot analysis, immunofluorescence assay, and flow cytometry; constructed PFN1-overexpressing and -knockdown cell lines; and detected ubiquitinated CD138 in the cells of both cell lines. Overexpression of PFN1 or PFN1-induced autophagy downregulated CD138 expression. Owing to the stemness and resistance of CD138- MM cells, inhibition of autophagy or CD138 overexpression reversed the resistance of PFN1-overexpressing MM cells to bortezomib, as indicated in our clonogenic, apoptosis, and CCK-8 assays. These results indicated that CD138 plays an important role in the resistance of MM cells to bortezomib. Targeting PFN1, CD138, or autophagic pathways may provide a promising therapeutic strategy for overcoming PFN1-induced drug resistance in MM.

DOI: https://doi.org/10.1007/s12672-025-02036-x
Cell Stem Cell. 2025 Mar 06. pii: S1934-5909(25)00045-1. [Epub ahead of print]32(3): 335-337

PSPC1 bridges cancer stemness and malignancy in acute myeloid leukemia.

Hsi-Wen Yeh, Yaw-Dong Lang, Hsin-Yi Lee, Yuh-Shan Jou.

In a recent publication in Cell Stem Cell, Hong et al.1 uncovered paraspeckle component 1 (PSPC1) as a determinant of leukemogenic characteristics in acute myeloid leukemia (AML). PSPC1 is not essential for normal hematopoiesis but it is upregulated to interact with PU.1 to promote AML progression and is also emerging as a therapeutic target.

DOI: https://doi.org/10.1016/j.stem.2025.02.006
bioRxiv. 2025 Feb 24. pii: 2025.02.19.638991. [Epub ahead of print]

RBM15-MKL1 fusion protein promotes leukemia via m6A methylation and WNT pathway activation.

Madeline Y Mayday, Giulia Biancon, Manyi Wei, Christian Ramirez, Irene Moratti, Andreas P Pintado-Urbanc, Lin Wang, Jether Amos Espinosa, Matthew D Simon, Yaara Ofir-Rosenfeld, Oliver Rausch, Toma Tebaldi, Stephanie Halene, Diane S Krause.

Acute megakaryoblastic leukemia driven by the RBM15-MKL1 fusion protein (RM-AMKL) is the only known recurrent mutation involving the N6-methyladenosine (m6A) writer complex. Dysregulation of m6A modification affects RNA fate and is linked to oncogenesis. Inhibition of m6A deposition via inhibition of the METTL3 writer protein has anti-tumour activity, but the mechanism underlying its efficacy and cancer specificity remains unclear. We treated murine RM-AMKL cells with a novel METTL3 inhibitor, STM3675, and showed apoptosis in vitro and prolonged survival of mice transplanted with RM-AMKL, implicating m6A as an essential component of AMKL and identifying Wnt signalling as a key driver of leukemogenesis. To elucidate the mechanism by which m6A contributes to leukemogenesis we employed a multi-omic approach, combining transcriptome-wide assessment of RNA binding, methylation and turnover. We show for the first time that RM retains the RNA-binding and m6A-modifiying functions of its RBM15 component, while also selectively regulating distinct mRNA targets, particularly genes involved in Wnt signalling including Frizzled. Frizzled genes are upregulated by RM and downregulated in RM-AMKL cells in response to METTL3 inhibition, providing an m6A-dependent explanation for their upregulation. Direct Frizzled knockdown reduced RM-AMKL growth, which was partially rescued by treatment with a β-catenin agonist, underscoring a functional role of Wnt signalling in RM-AMKL. Human AMKLs show elevated Wnt pathway and Frizzled gene expression, highlighting the relevance of our work. Together, our findings reveal that RM-specific m6A modifications and activation of Wnt signalling are critical drivers of RM-AMKL, highlighting these pathways as potential therapeutic targets.
Key Points: RM retains functional abilities of RBM15 and additionally interacts with Wnt-related transcripts to increase expression of Fzd proteins.The METTL3 writer complex and WNT signalling pathways are essential for RM-driven leukemia.

DOI: https://doi.org/10.1101/2025.02.19.638991
Cell Death Dis. 2025 Mar 08. 16(1): 165

Oncogenic and microenvironmental signals drive cell type specific apoptosis resistance in juvenile myelomonocytic leukemia.

Naile Koleci, Ying Wu, Niels Anton Wehner, Jovana Rajak, Venugopal Rao Mittapalli, Julia Mergner, Hui Xiao, Jun Wang, Madeleine Wahl, Sheila Bohler, Konrad Aumann, Georg Häcker, Senthilkumar Ramamoorthy, Melanie Boerries, Susanne Kirschnek, Miriam Erlacher.

Juvenile myelomonocytic leukemia (JMML) is caused by constitutively activated RAS signaling and characterized by increased proliferation and predominant myelomonocytic differentiation of hematopoietic cells. Using MxCre;Ptpn11D61Y/+ mice, which model human JMML, we show that RAS pathway activation affects apoptosis signaling through cell type-dependent regulation of BCL-2 family members. Apoptosis resistance observed in monocytes and granulocytes was mediated by overexpression of the anti-apoptotic and down-regulation of the pro-apoptotic members of the BCL-2 family. Two anti-apoptotic proteins, BCL-XL and MCL-1, were directly regulated by the oncogenic RAS signaling but, in addition, were influenced by microenvironmental signals. While BCL-XL and BCL-2 were required for the survival of monocytes, MCL-1 was essential for neutrophils. Interestingly, stem and progenitor cells expressing the oncogenic PTPN11 mutant showed no increased apoptosis resistance. BCL-XL inhibition was the most effective in killing myeloid cells in vitro but was insufficient to completely resolve myeloproliferation in vivo.

DOI: https://doi.org/10.1038/s41419-025-07479-2