bims-tremyl 2024-12-29 papers

bims-tremyl

Biomed News

on Therapy resistance biology in myeloid leukemia

Issue of 2024–12–29
29 papers selected by
Paolo Gallipoli, Barts Cancer Institute, Queen Mary University of London

Outcomes of Patients With Treated Secondary Acute Myeloid Leukemia: A High-Risk Subtype That Warrants an Independent Prognostic Designation.
Advancing the outcomes of AML out of antecedent MPN by targeting mutated IDH1.
Menin inhibitors in the treatment of acute myeloid leukemia.
Bone-Marrow-Targeted Nanocomposite Abrogates C-Myb-Survivin Cross Talk in MLL-AF9-Rearranged Acute Myeloid Leukemia in In Vitro and In Vivo Patient-Derived Xenograft Models.
TIM-3 marks measurable residual leukemic stem cells responsible for relapse after allogeneic stem cell transplantation.
HMGA2 overexpression with specific chromosomal abnormalities predominate in CALR and ASXL1 mutated myelofibrosis.
Outcome of Splenectomy in JAK2 Inhibitor Treated Patients With Myelofibrosis: A Mayo Clinic Experience in 34 Consecutive Cases.
Metabolic Adaptations To Acute Glucose Uptake Inhibition Converge Upon Mitochondrial Respiration For Leukemia Cell Survival.
How I Treat AML relapse after allogeneic HCT.
Different effects of fatty acid oxidation on hematopoietic stem cells based on age and diet.
BH3 Mimetics Augment Cytotoxic T Cell Killing of Acute Myeloid Leukemia via Mitochondrial Apoptotic Mechanism.
Significance of cycle 1 bone marrow biopsy in predicting outcomes and toxicities of venetoclax-based therapy for myeloid malignancies.
Long-read epigenomic diagnosis and prognosis of Acute Myeloid Leukemia.
Genome-wide CRISPR screen identifies AraC-Dauno-Eto (ADE) response modulators that predicts outcome in pediatric AML.
Catalytic inhibition of KAT6/KAT7 enhances the efficacy and overcomes primary and acquired resistance to Menin inhibitors in MLL leukaemia.
Tumor Lysis Syndrome in Acute Myeloid Leukemia Patients Treated With a Venetoclax Based Regimen.
Comparison of HiDAC Versus FLAG-IDA in the Treatment of Relapsed Acute Myeloid Leukemia and High-Risk Myelodysplastic Syndrome.
Psychiatric and substance use disorders predict poor outcomes in older veterans with acute myeloid leukemia.
Transforming growth factor beta receptor type I (TGF-βRI) kinase inhibitors IOA-359 and IOA-360 stimulate erythropoiesis in MDS.
3D chromatin hubs as regulatory units of identity and survival in human acute leukemia.
Novel Treatment Strategies for Chronic Myeloid Leukemia.
CPX-351 +/- gemtuzumab ozogamicin as induction therapy for adult patients with newly diagnosed, favourable-intermediate risk, FLT3-ITD negative, AML: A pilot study.
ALDH Enzymes and Hematological Diseases: A Scoping Review of Literature.
Reconsidering the usual suspects in age-related hematologic disorders: is stem cell dysfunction a root cause of aging?
Real-World Treatment Patterns and Healthcare Resource Use for Patients with Myelofibrosis: Results from the METER Study.
Humanized anti-CD25 monoclonal antibody replaces methotrexate as acute graft-versus-host disease prophylaxis in haploidentical allogeneic haematopoietic stem cell transplantation.
A novel human pluripotent stem cell gene activation system identifies IGFBP2 as a mediator in the production of haematopoietic progenitors in vitro.
Effects of Aging on Glucose and Lipid Metabolism in Mice.
Molecular and Clinical Risk Factors Associated with Thrombosis and Bleeding in Myelofibrosis Patients.

Am J Hematol. 2024 Dec 24.

Outcomes of Patients With Treated Secondary Acute Myeloid Leukemia: A High-Risk Subtype That Warrants an Independent Prognostic Designation.

Jayastu Senapati, Hagop M Kantarjian, Fadi G Haddad, Nicholas J Short, Gautam Borthakur, Rashmi Kanagal-Shamanna, Guilin Tang, Elias Jabbour, Courtney D DiNardo, Naval Daver, Guillermo Montalban-Bravo, Vishrut Shah, Amin Alousi, Elizabeth Shpall, Uday Popat, Guillermo Garcia-Manero, Farhad Ravandi, Tapan M Kadia.

  Patients who develop acute myeloid leukemia (AML) after having received treatment for myelodysplastic syndrome (MDS) or related conditions have particularly poor outcomes. This study analyzed adult patients with newly diagnosed AML who previously had MDS, chronic myelomonocytic leukemia (CMML), or MDS/myeloproliferative neoplasm (MPN) overlap syndrome, and who had received hypomethylating agents, chemotherapy, and/or allogeneic stem cell transplantation (HSCT) for these antecedent disorders. From January 2012 to August 2023, we included 673 patients with a median age of 70 years (range, 19-94); 536 (80%) had transformed from MDS, and the remainder from CMML or MDS-MPN. Additionally, 149 patients (22%) had prior therapy for nonmyeloid malignancies. Among 497 evaluable patients, 289 (58%) had adverse-risk (AR) cytogenetics, 34% had TP53 mutation/s, and 71% were classified as AR by the ELN 2017 criteria. Most patients (67%) received low-intensity therapy (LIT) for AML, and 27% were treated with venetoclax. The overall response rate was 37%, and venetoclax improved the odds of response (OR = 2.5, 95% CI 1.6-3.7) in LIT-treated patients. At a median follow-up of 43 months, the median relapse-free survival (RFS) and overall survival (OS) were 4.6 and 4.8 months, respectively. Multivariate analysis showed that prior therapy for nonmyeloid disorders (HR = 1.30), ≥ 2 lines of therapy for antecedent myeloid disorders (HR = 1.23), and ELN AR risk (HR = 1.47) increased the hazards of death, while HSCT (HR = 0.50) was beneficial and validated on gradient-boosted regression. TS-AML is associated with poor outcomes irrespective of AML genomics and treatment, highlighting the need for its inclusion as an independent AR category for accurate prognostication and clinical trial reporting.

Keywords:  TP53; myelodysplastic syndrome; secondary acute myeloid leukemia; stem cell transplantation; venetoclax

DOI:  https://doi.org/10.1002/ajh.27561
Br J Haematol. 2024 Dec 22.

Advancing the outcomes of AML out of antecedent MPN by targeting mutated IDH1.

Keith W Pratz.

  Outcomes of myeloproliferative neoplasms (MPN)-associated acute leukaemias are dismal with conventional therapy. Approximately 20% of MPN-associated acute leukaemias have mutations in isocitrate dehydrogenase (IDH). Olutasidenib, and inhibitor of IDH1, demonstrates important clinical benefits in MPN-associated leukaemia with IDH1 mutation. Commentary on: Botton et al. Olutasidenib demonstrates significant clinical activity in mutated IDH1 acute myeloid leukemia arising from a prior myeloproliferative neoplasm. Br J Haematol 2024 (Online ahead of print). doi: 10.1111/bjh.19944.

Keywords:  MPN; acute leukaemias; olutasidenib

DOI:  https://doi.org/10.1111/bjh.19959
Blood. 2024 Dec 24. pii: blood.2024026232. [Epub ahead of print]

Menin inhibitors in the treatment of acute myeloid leukemia.

Gerwin A Huls, Carolien M Woolthuis, Jan Jacob Schuringa.

Acute myeloid leukemia (AML) is a heterogeneous hematologic malignancy characterized by the (oligo)clonal expansion of myeloid progenitor cells. Despite advances in treatment, AML remains challenging to cure, particularly in patients with specific genetic abnormalities. Menin inhibitors have emerged as a promising therapeutic approach, targeting key genetic drivers of AML such as KMT2A rearrangements and NPM1 mutations. Here, we review the clinical value of menin inhibitors, highlighting their mechanism of action, efficacy, safety, and potential to transform AML treatment.

DOI: https://doi.org/10.1182/blood.2024026232
ACS Appl Mater Interfaces. 2024 Dec 22.

Bone-Marrow-Targeted Nanocomposite Abrogates C-Myb-Survivin Cross Talk in MLL-AF9-Rearranged Acute Myeloid Leukemia in In Vitro and In Vivo Patient-Derived Xenograft Models.

Avinash Chandra Kushwaha, Boddu Mrunalini, Pankaj Malhotra, Surajit Karmakar, Subhasree Roy Choudhury.

  The heterogeneous form of malignancy in the myeloid lineage of normal hematopoietic stem cells (HSCs) is characterized as acute myeloid leukemia (AML). The t(9;11) reciprocal translocation (p22;q23) generates MLL-AF9 oncogene, which results in myeloid-based monoblastic AML with frequent relapse and poor survival. MLL-AF9 binds with the C-Myb promoter and regulates AML onset, maintenance, and survival. The bone marrow microenvironment (BMM) protects leukemia stem cells (LSCs) from therapeutic agents, which can lead to relapsed condition. Targeting leukemia BMM can be a viable therapeutics approach for AML treatment, wherein bone homing bisphosphonate, ibandronic acid (IBD), can localize to the BMM. In order to target the BMM of AML, C-Myb siRNA was entrapped in Vitamin D nanoemulsion-functionalized with BMM-targeted IBD, which exhibited binding with ex vivo bone slices and localization into mice bone marrow. IBD functionalization and C-Myb siRNA nanotherapy enhanced the suppression of LSCs (c-Kit+) and the upregulation of myeloid differentiation markers CD11b and Gr-1 in peripheral blood and bone marrow of athymic nude mice and patient-derived xenograft models. IBD functionalization enhanced the downregulation of C-Myb and C-Myb-Survivin cross talk in bone marrow and spleen tissue responsible for AML onset, maintenance, and pathogenesis. Further C-Myb binding to Survivin promoter was abrogated by the present bone-marrow-targeted nanotherapy, signifying its translational potential for AML therapeutics.

Keywords:  AML; MLL-AF9; PDX; bone marrow microenvironment; siRNA nanotherapy; xenograft

DOI:  https://doi.org/10.1021/acsami.4c18737
Cancer Sci. 2024 Dec 26.

TIM-3 marks measurable residual leukemic stem cells responsible for relapse after allogeneic stem cell transplantation.

Teppei Sakoda, Yoshikane Kikushige, Hidetoshi Irifune, Gentaro Kawano, Takuya Harada, Yuichiro Semba, Masayasu Hayashi, Takahiro Shima, Yasuo Mori, Tetsuya Eto, Tomohiko Kamimura, Hiromi Iwasaki, Ryosuke Ogawa, Goichi Yoshimoto, Koji Kato, Takahiro Maeda, Toshihiro Miyamoto, Koichi Akashi.

  In this study, we investigated the measurable residual leukemic stem cell (MR-LSC) population after allogeneic stem cell transplantation (allo-SCT) for high-risk acute myeloid leukemia (AML), utilizing T-cell immunoglobulin mucin-3 (TIM-3) expression as a functional marker of AML leukemic stem cells (LSCs). Analysis of the CD34+CD38- fraction of bone marrow cells immediately after achievement of engraftment revealed the presence of both TIM-3+LSCs and TIM-3- donor hematopoietic stem cells (HSCs) at varying ratios. Genetic analysis confirmed that TIM-3+ cells harbored patient-specific mutations identical to those found in AML clones, whereas TIM-3- cells did not, indicating that TIM-3+CD34+CD38- cells represent residual AML LSCs. In 92 allo-SCT occasions involving 83 AML patients, we enumerated the frequencies of TIM-3+LSCs immediately after achieving hematologic complete remission with complete donor cell chimerism. Notably, only 22.2% of patients who achieved a TIM-3+MR-LSClow status (<60%) experienced relapse, with a median event-free survival (EFS) of 1581 days (median follow-up duration was 2177 days among event-free survivors). Conversely, 87.5% of patients with TIM-3+MR-LSCint/high (≥60%) relapsed, with a median EFS of 140.5 days. Furthermore, MR-LSC status emerged as a significant independent risk factor for relapse (hazard ratio, 8.56; p < 0.0001), surpassing the impact of patient disease status prior to allo-SCT, including failure to achieve complete remission (hazard ratio, 1.98; p = 0.048). These findings suggest that evaluating TIM-3+ MR-LSCs immediately after engraftment, which reflects the competitive reconstitution of residual TIM-3+ LSCs and donor HSCs, may be valuable for predicting outcomes in AML patients undergoing allo-SCT.

Keywords:  TIM‐3; acute myeloid leukemia; allogeneic stem cell transplantation; leukemic stem cells; measurable residual disease

DOI:  https://doi.org/10.1111/cas.16431
Leukemia. 2024 Dec 23.

HMGA2 overexpression with specific chromosomal abnormalities predominate in CALR and ASXL1 mutated myelofibrosis.

Shivani Handa, Christoph Schaniel, Joseph Tripodi, Daiva Ahire, Md Babu Mia, Sophie Klingborg, Douglas Tremblay, Bridget K Marcellino, Ronald Hoffman, Vesna Najfeld.

Although multiple genetic events are thought to play a role in promoting progression of the myeloproliferative neoplasms (MPN), the individual events that are associated with the development of more aggressive disease phenotypes remain poorly defined. Here, we report that novel genomic deletions at chromosome 12q14.3, as detected by a high-resolution array comparative genomic hybridization plus single nucleotide polymorphisms platform, occur in 11% of MPN patients with myelofibrosis (MF) and MPN-accelerated/blast phase (AP/BP) but was not detected in patients with polycythemia vera or essential thrombocythemia. These 12q14.3 deletions resulted in the loss of most of the non-coding region of exon 5 and MIRLET7 binding sites in the 3'UTR of the high mobility group AT hook 2 (HMGA2), which negatively regulate HMGA2 expression. These acquired 12q14.3 deletions were predominately detected in MF patients with CALR and ASXL1 co-mutations and led to a greater degree of HMGA2 transcript overexpression, independent of the presence of an ASXL1 mutation. Patients with 12q structural abnormalities involving HMGA2 exhibited a more aggressive clinical course, with a higher frequency of MPN-AP/BP evolution. These findings indicate that HMGA2 overexpression associated with genomic deletion of its 3'UTR region is a newly recognized genetic event that contributes to MPN progression.

DOI: https://doi.org/10.1038/s41375-024-02496-0
Am J Hematol. 2024 Dec 26.

Outcome of Splenectomy in JAK2 Inhibitor Treated Patients With Myelofibrosis: A Mayo Clinic Experience in 34 Consecutive Cases.

Patricia Carey, Animesh Pardanani, Patrick Starlinger, Ayalew Tefferi, Naseema Gangat.



Keywords:   JAK2 ; myeloproliferative; thrombosis; transplant

DOI:  https://doi.org/10.1002/ajh.27570
bioRxiv. 2024 Nov 22. pii: 2024.11.20.624567. [Epub ahead of print]

Metabolic Adaptations To Acute Glucose Uptake Inhibition Converge Upon Mitochondrial Respiration For Leukemia Cell Survival.

Monika Komza, Jesminara Khatun, Jesse D Gelles, Andrew P Trotta, Ioana Abraham-Enachescu, Juan Henao, Ahmed Elsaadi, Andriana G Kotini, Cara Clementelli, JoAnn Arandela, Sebastian El Ghaity-Beckley, Agneesh Barua, Yiyang Chen, Bridget K Marcellino, Eirini P Papapetrou, Masha V Poyurovsky, Jerry Edward Chipuk.

One hallmark of cancer is the upregulation and dependency on glucose metabolism to fuel macromolecule biosynthesis and rapid proliferation. Despite significant pre-clinical effort to exploit this pathway, additional mechanistic insights are necessary to prioritize the diversity of metabolic adaptations upon acute loss of glucose metabolism. Here, we investigated a potent small molecule inhibitor to Class I glucose transporters, KL-11743, using glycolytic leukemia cell lines and patient-based model systems. Our results reveal that while several metabolic adaptations occur in response to acute glucose uptake inhibition, the most critical is increased mitochondrial oxidative phosphorylation. KL-11743 treatment efficiently blocks the majority of glucose uptake and glycolysis, yet markedly increases mitochondrial respiration via enhanced Complex I function. Compared to partial glucose uptake inhibition, dependency on mitochondrial respiration is less apparent suggesting robust blockage of glucose uptake is essential to create a metabolic vulnerability. When wild-type and oncogenic RAS patient-derived induced pluripotent stem cell acute myeloid leukemia (AML) models were examined, KL-11743 mediated induction of mitochondrial respiration and dependency for survival associated with oncogenic RAS. Furthermore, we examined the therapeutic potential of these observations by treating a cohort of primary AML patient samples with KL-11743 and witnessed similar dependency on mitochondrial respiration for sustained cellular survival. Together, these data highlight conserved adaptations to acute glucose uptake inhibition in diverse leukemic models and AML patient samples, and position mitochondrial respiration as a key determinant of treatment success.

DOI: https://doi.org/10.1101/2024.11.20.624567
Blood. 2024 Dec 24. pii: blood.2024025705. [Epub ahead of print]

How I Treat AML relapse after allogeneic HCT.

Mahasweta Gooptu, H Moses Murdock, Robert J Soiffer.

Allogeneic hematopoietic stem-cell transplantation (HCT) is one of the principal curative approaches in the treatment of acute myeloid leukemia (AML); however, relapse post-transplantation remains a catastrophic event with poor prognosis. The incidence of relapse has remained unchanged over the last three decades despite an evolving understanding of the immunobiology of the graft-versus leukemia effect and the immune escape mechanisms that lead to post-HCT relapse. The approach to post-transplant relapse is highly individualized and is dictated both by disease biology and genomics as well as the patient's clinical status at the time of relapse and the interval between relapse and transplantation. With the help of three illustrative cases, we discuss our approach to early, late, and incipient relapse. Current therapeutic strategies incorporate immunosuppression taper when feasible, a variety of targeted and non-targeted chemotherapeutic agents and consolidative cellular therapies including donor lymphocyte infusions or a second allogeneic transplant. We then summarize evolving frontiers in the treatment and prognostication of relapse including the critical role of measurable residual disease. Finally, we emphasize enrollment on clinical trials and thoughtful discussions regarding goals of care and supporting frail patients as universal principles that should be incorporated in approaches to treatment of AML relapse post-transplantation.

DOI: https://doi.org/10.1182/blood.2024025705
Cell Stem Cell. 2024 Dec 12. pii: S1934-5909(24)00413-2. [Epub ahead of print]

Different effects of fatty acid oxidation on hematopoietic stem cells based on age and diet.

Salma Merchant, Animesh Paul, Amanda Reyes, Daniel Cassidy, Ashley Leach, Dohun Kim, Sarah Muh, Gerik Grabowski, Gerta Hoxhaj, Zhiyu Zhao, Sean J Morrison.

  Fatty acid oxidation is of uncertain importance in most stem cells. We show by 14C-palmitate tracing and metabolomic analysis that hematopoietic stem/progenitor cells (HSPCs) engage in long-chain fatty acid oxidation that depends upon carnitine palmitoyltransferase 1a (CPT1a) and hydroxyacyl-CoA dehydrogenase (HADHA) enzymes. CPT1a or HADHA deficiency had little or no effect on HSPCs or hematopoiesis in young adult mice. Young HSPCs had the plasticity to oxidize other substrates, including glutamine, and compensated for loss of fatty acid oxidation by decreasing pyruvate dehydrogenase phosphorylation, which should increase function. This metabolic plasticity declined as mice aged, when CPT1a or HADHA deficiency altered hematopoiesis and impaired hematopoietic stem cell (HSC) function upon serial transplantation. A high-fat diet increased fatty acid oxidation and reduced HSC function. This was rescued by CPT1a or HADHA deficiency, demonstrating that increased fatty acid oxidation can undermine HSC function. Long-chain fatty acid oxidation is thus dispensable in young HSCs but necessary during aging and deleterious with a high-fat diet.

Keywords:  aging; fatty acid; hematopoiesis; high-fat diet; metabolic plasticity; metabolism; mitochondria; β-oxidation

DOI:  https://doi.org/10.1016/j.stem.2024.11.014
Res Sq. 2024 Dec 09. pii: rs.3.rs-5307127. [Epub ahead of print]

BH3 Mimetics Augment Cytotoxic T Cell Killing of Acute Myeloid Leukemia via Mitochondrial Apoptotic Mechanism.

Cassian Yee, Kapil Saxena, Esther Ryu, Shao-Hsi Hung, Shailbala Singh, Qi Zhang, Zhihong Zeng, Zhe Wang, Marina Konopleva.

Adoptive cell therapy (ACT) can address an unmet clinical need for patients with relapsed/refractory acute myeloid leukemia (AML), but its effect is often modest in the setting of high tumor burden. In this study, we postulated that strategies to lower the AML apoptotic threshold will augment T cell killing of AML cells. BH3 mimetics, such as venetoclax, are a clinically approved class of compounds that predispose cells to intrinsic apoptosis by inhibiting anti-apoptotic mitochondrial proteins. We explored the anti-leukemic efficacy of BH3 mimetics combined with WT1-specific CD8 + T cells on AML cell lines and primary samples from patients with a diverse array of disease characteristics to evaluate if lowering the cellular apoptotic threshold via inhibition of anti-apoptotic mitochondrial proteins can increase leukemic cell sensitivity to T cell therapy. We found that the combination approach of BH3 mimetic and CD8 + T cells led to significantly increased killing of established AML lines as well as of adverse-risk primary AML leukemic blast cells. In contrast to the hypothesis that enhanced killing would be due to combined activation of the intrinsic and extrinsic apoptotic pathways, we found that CTL-mediated killing of AML cells was accomplished primarily through activation of the intrinsic/mitochondrial apoptotic pathway. This highly effective combinatorial activity due to convergence on the same apoptotic pathway was conserved across multiple AML cell lines and primary samples, suggesting that mitochondrial priming may represent a novel mechanism of optimizing adoptive cell therapy for AML patients.

DOI: https://doi.org/10.21203/rs.3.rs-5307127/v1
Leuk Lymphoma. 2024 Dec 27. 1-7

Significance of cycle 1 bone marrow biopsy in predicting outcomes and toxicities of venetoclax-based therapy for myeloid malignancies.

Jeffrey Baron, Daniel Appiah, Mark G Faber, Han Yu, Tara Cronin, Jared Vega, Samantha Poblete, Pamela J Sung, Elizabeth A Griffiths, Amanda Przespolewski, James E Thompson, Steven Green, Eunice S Wang.

  For older unfit patients receiving venetoclax-based induction, data on the significance of interim bone marrow biopies (BMBx) findings on clinical outcomes is lacking. We retrospectively evaluated interim BMBx results performed on Cycle 1 days 21-28 of venetoclax-based therapy in 69 adults with myeloid malignancies to determine whether blast clearance was associated with overall survival (OS) and overall response rate (ORR). Median age was 75 years (range 69-78). Results demonstrated blast reduction (BR, <5% blasts) in 71%. Venetoclax was held to allow count recovery in 86% of these patients. Achieving interim BMBx BR was significantly associated with OS (p = 0.0033) and ORR (Cohen's kappa 0.39). Patients whose venetoclax was held experienced low rates of infection and reduced cytopenias. These findings support the importance of cycle 1 BMBx assessment during venetoclax-based therapies, specifically in predicting which patients will achieve optimal outcomes and in mitigating toxicity.

Keywords:  Myeloid malignancies; bone marrow biopsy response; low-intensity chemotherapy; therapy management; venetoclax

DOI:  https://doi.org/10.1080/10428194.2024.2444480
Res Sq. 2024 Dec 12. pii: rs.3.rs-5450972. [Epub ahead of print]

Long-read epigenomic diagnosis and prognosis of Acute Myeloid Leukemia.

Jatinder Lamba, Francisco Marchi, Marieke Landwehr, Ann-Kathrin Schade, Vivek Shastri, Matin Ghavami, Fernando Sckaff, Richard Marrero, Nam Nguyen, Vikash Mansinghka, Xueyuan Cao, William Slayton, Petr Starostik, Raul Ribeiro, Jeffrey Rubnitz, Jeffery Klco, Alan Gamis, Timothy Triche, Rhonda Ries, Edwards Anders Kolb, Richard Aplenc, Todd Alonzo, Stanley Pounds, Soheil Meshinchi, Christopher Cogle, Abdelrahman Elsayed.

Acute Myeloid Leukemia (AML) is an aggressive cancer with dismal outcomes, vast subtype heterogeneity, and suboptimal risk stratification. In this study, we harmonized DNA methylation data from 3,314 patients across 11 cohorts to develop the Acute Leukemia Methylome Atlas (ALMA) of diagnostic relevance that predicted 27 WHO 2022 acute leukemia subtypes with an overall accuracy of 96.3% in discovery and 90.1% in validation cohorts. Specifically, for AML, we also developed AML Epigenomic Risk , a prognostic classifier of overall survival (OS) (HR=4.40; 95% CI=3.45-5.61; P<0.0001), and a targeted 38CpG AML signature using a stepwise EWAS-CoxPH-LASSO model predictive of OS (HR=3.84; 95% CI=3.01-4.91; P<0.0001). Finally, we developed a specimen-to-result protocol for simultaneous whole-genome and epigenome sequencing that accurately predicted diagnoses and prognoses from twelve prospectively collected patient samples using long-read sequencing. Our study unveils a new paradigm in acute leukemia management by leveraging DNA methylation for diagnostic and prognostic applications.

DOI: https://doi.org/10.21203/rs.3.rs-5450972/v1
Blood Adv. 2024 Dec 23. pii: bloodadvances.2024014157. [Epub ahead of print]

Genome-wide CRISPR screen identifies AraC-Dauno-Eto (ADE) response modulators that predicts outcome in pediatric AML.

Nam Hk Nguyen, Roya Rafiee, Phani Krishan Parcha, Abderrahmane Tagmount, Jeffrey Rubnitz, Raul C Ribeiro, Xueyuan Cao, Stanley B Pounds, Christopher D Vulpe, Jatinder Kaur Lamba.

Cytarabine, daunorubicin, and etoposide (ADE) have been the standard backbone of induction chemotherapy regimens for acute myeloid leukemia (AML) patients for over five decades. However, chemoresistance is still a major concern, and a significant proportion of AML becomes resistant to ADE treatment leading to relapse and poor survival. Therefore, there is a significant need to identify mechanisms mediating drug resistance to overcome chemoresistance. Herein, we performed genome-wide synthetic lethal CRISPR/Cas9 screens using araC, daunorubicin and etoposide. We further integrated significant findings from the CRISPR screen with outcome in pAML patients treated with standard ADE regimen on 3 independent clinical trials to identify drug response biomarkers of prognostic significance. We identified seveal mediators that would represent clinically and biologically significant genes for ADE treatment, such as BCL2, CLIP2, and VAV3, which are resistant genes with high expression associated with poor outcomes in pAML treated with ADE, and GRPEL1, HCFC1, and TAF10, which are sensitive genes with high expression showing beneficial outcomes. Notably, knockdowns of the BCL2, CLIP2, and VAV3 genes sensitize the ADE component in AML cell lines, suggesting that these genes should be further studied as potential therapeutic targets to overcome chemoresistance.

DOI: https://doi.org/10.1182/bloodadvances.2024014157
bioRxiv. 2024 Dec 12. pii: 2024.12.11.627663. [Epub ahead of print]

Catalytic inhibition of KAT6/KAT7 enhances the efficacy and overcomes primary and acquired resistance to Menin inhibitors in MLL leukaemia.

Shellaina J V Gordon, Florian Perner, Laura MacPherson, Daniela V Wenge, Wallace Bourgeois, Katie Fennell, Tabea Klaus, Jelena Petrovic, Jakub Horvath, Joan Cao, John Lapek, Sean Uryu, Jeffrey White, Enid Y N Lam, Xinmeng Jasmine Mu, Yih-Chih Chan, Andrea Gillespie, Benjamin Blyth, Michelle A Camerino, Ylyva E Bozikis, Henrietta Holze, Kathy Knezevic, Jesse Balic, Paul A Stupple, Ian P Street, Brendon J Monahan, Shikhar Sharma, Elanor N Wainwright, Dane Vassiliadis, Thomas A Paul, Scott A Armstrong, Mark A Dawson.

Understanding the molecular pathogenesis of MLL fusion oncoprotein (MLL-FP) leukaemia has spawned epigenetic therapies that have improved clinical outcomes in this often-incurable disease. Using genetic and pharmacological approaches, we define the individual and combined contribution of KAT6A, KAT6B and KAT7, in MLL-FP leukaemia. Whilst inhibition of KAT6A/B is efficacious in some pre-clinical models, simultaneous targeting of KAT7, with the novel inhibitor PF-9363, increases the therapeutic efficacy. KAT7 interacts with Menin and the MLL complex and is co-localised at chromatin to co-regulate the MLL-FP transcriptional program. Inhibition of KAT6/KAT7 provides an orthogonal route to targeting Menin to disable the transcriptional activity of MLL-FP. Consequently, combined inhibition rapidly evicts the MLL-FP from chromatin, potently represses oncogenic transcription and overcomes primary resistance to Menin inhibitors. Moreover, PF-9363 or genetic depletion of KAT7 can also overcome acquired genetic/non-genetic resistance to Menin inhibition. These data provide the molecular rationale for rapid clinical translation of combination therapy in MLL-FP leukaemia.

DOI: https://doi.org/10.1101/2024.12.11.627663
Eur J Haematol. 2024 Dec 26.

Tumor Lysis Syndrome in Acute Myeloid Leukemia Patients Treated With a Venetoclax Based Regimen.

Margaret Rowe, Daria Babushok, Martin Carroll, Alison Carulli, Noelle Frey, Saar Gill, Elizabeth Hexner, Rebecca Hirsh, Nasheed Hossain, Catherine Lai, Alison Loren, Selina Luger, Ivan Maillard, Shannon McCurdy, Andrew Matthews, Mary Ellen Martin, Vikram R Paralkar, Alexander Perl, David Porter, Keith Pratz, Edward Stadtmauer, Ximena Jordan Bruno.

  Venetoclax with hypomethylating agents (HMA) is the standard of care for acute myeloid leukemia (AML) in patients ineligible for intensive chemotherapy and is associated with tumor lysis syndrome (TLS). TLS prophylaxis and the use of Cairo Bishop versus Howard diagnostic criteria are not standardized. Here we report TLS prophylaxis and incidence in a retrospective cohort of 100 consecutive AML patients treated with venetoclax and HMA. Thirty four patients developed laboratory Cairo Bishop TLS; 8 of these met criteria for clinical Cairo Bishop TLS. Only 6 of patients met Howard TLS criteria. Fourteen patients had spontaneous TLS. Ninety two out of 100 patients had a white blood cell count (WBC) < 25 000 cells/μL at treatment start. Prophylaxis like the original venetoclax trial with allopurinol (56%), intravenous fluids (21%), and frequent lab monitoring (56%) was less common. There was a trend toward increased Cairo Bishop TLS in patients with WBC ≥ 15 000 cells/μL. In our study Howard TLS criteria better identified patients with significant TLS. Aggressive TLS prophylaxis was uncommon in our cohort and is likely unnecessary for most patients at low risk of TLS.

Keywords:  Leukoreduction; Venetoclax; acute myeloid leukemia; prophylaxis; tumor lysis syndrome

DOI:  https://doi.org/10.1111/ejh.14371
Eur J Haematol. 2024 Dec 26.

Comparison of HiDAC Versus FLAG-IDA in the Treatment of Relapsed Acute Myeloid Leukemia and High-Risk Myelodysplastic Syndrome.

Man Wai Tang, Deborah Van der Tuin, Mesire Aydin, Jarom Heijmans, Arjan A Van de Loosdrecht, Ellen Meijer, Caroline E Rutten, Mariëlle Wondergem, Jeroen J W M Janssen, Marjolein L Donker, Mette D Hazenberg, Sonja Zweegman, Bart J Biemond, David C De Leeuw, Erfan Nur.

   BACKGROUND: Relapsed acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (HR-MDS) are associated with a poor prognosis. It is unknown which re-induction therapy provides the highest chance of durable remission. Commonly used therapies are high dose cytarabine (HiDAC) and triple therapy consisting of fludarabine, cytarabine, and idarubicin combined with granulocyte colony-stimulating factor (FLAG-IDA).
METHODS: Two patient cohorts with relapsed AML or HR-MDS treated with HiDAC or FLAG-IDA between October 2015 and December 2021 in two academic hospitals in the Netherlands were retrospectively analyzed.
RESULTS: Patients were treated with either HiDAC (n=22) or FLAG-IDA (n=25). Rates of CR (71% vs. 74%, P=0.85), 1-year OS (47% vs. 51%, P=0.99) and EFS (38% vs. 35%, P=0.71) were comparable between HiDAC and FLAG-IDA. Durations of neutropenia (median 24 days (IQR 20-26) vs. 30 days (IQR 22-39), P=0.014) and thrombocytopenia (22 days (IQR 17-26) vs. 36 days (IQR 26-53)) were significantly shorter in the HiDAC group than in the FLAG-IDA group.
CONCLUSION: While remission rates and survival outcomes were similar, FLAG-IDA was associated with longer periods of myelosuppression and transfusion dependency compared to HiDAC in these two cohorts. HiDAC can be considered as a salvage chemotherapyfor relapsed AML/HR-MDS based on our study.

Keywords:  MDS; chemotherapy; cytarabine; leukemia; myelosuppression

DOI:  https://doi.org/10.1111/ejh.14370
Blood Adv. 2024 Dec 23. pii: bloodadvances.2024014468. [Epub ahead of print]

Psychiatric and substance use disorders predict poor outcomes in older veterans with acute myeloid leukemia.

Michelle H Lee, Jennifer La, Mary T Brophy, Nhan V Do, Camille V Edwards, Clark DuMontier, Gabriela S Hobbs, Nathanael R Fillmore.

DOI: https://doi.org/10.1182/bloodadvances.2024014468
Leuk Lymphoma. 2024 Dec 27. 1-10

Transforming growth factor beta receptor type I (TGF-βRI) kinase inhibitors IOA-359 and IOA-360 stimulate erythropoiesis in MDS.

Nandini Ramachandra, Charan Thej Reddy Vegivinti, Srabani Sahu, Rahul Sanawar, Bianca Rivera-Peña, Sarah Aminov, Ariel Fromowitz, Jinghang Zhang, Fnu Aodengtuya, Kith Pradhan, Rongbao Zhao, Leya Schwartz, Srinivas Alluri, Victor Thiruvananthapuram, Emma Rabinovich, Opeyemi Ajibade, Shanisha Gordon-Mitchell, Aditi Shastri, Marcel Deken, Jonathan M Yingling, Scott Sawyer, Michael Lahn, Amit Verma.

  Overactivation of the Transforming Growth Factor Beta (TGF-β) pathway is implicated in the pathogenesis of cytopenias in Myelodysplastic syndromes (MDS) and Acute Myeloid Leukemia (AML). IOA-359 and IOA-360 are potent small molecule inhibitors of the TGF-beta Receptor type I kinase (TGF-βRI, also referred to as ALK5, activin receptor-like kinase 5) that abrogate SMAD phosphorylation in hematopoietic cell lines. Both inhibitors were able to inhibit TGF-β mediated gene transcription at specific doses. ALK5 inhibitors abrogated the growth inhibitory effects of TGF-β on healthy hematopoietic stem cells and stimulated hematopoietic differentiation in cell lines and MDS/AML specimens. These data demonstrate preclinical efficacy of two novel ALK5 inhibitors, IOA-359 and IOA-360, in stimulating erythroid differentiation in MDS and AML.

Keywords:  ALK5 inhibitors; Acute Myeloid Leukemia (AML); IOA-359 and IOA-360; Myelodysplastic Syndrome (MDS); TGF-β inhibitors

DOI:  https://doi.org/10.1080/10428194.2024.2444479
Mol Cell. 2024 Dec 17. pii: S1097-2765(24)00995-X. [Epub ahead of print]

3D chromatin hubs as regulatory units of identity and survival in human acute leukemia.

Giovanni Gambi, Francesco Boccalatte, Javier Rodriguez Hernaez, Ziyan Lin, Bettina Nadorp, Alexander Polyzos, Jimin Tan, Kleopatra Avrampou, Giorgio Inghirami, Alex Kentsis, Effie Apostolou, Iannis Aifantis, Aristotelis Tsirigos.

  Cancer progression involves genetic and epigenetic changes that disrupt chromatin 3D organization, affecting enhancer-promoter interactions and promoting growth. Here, we provide an integrative approach, combining chromatin conformation, accessibility, and transcription analysis, validated by in silico and CRISPR-interference screens, to identify relevant 3D topologies in pediatric T cell leukemia (T-ALL and ETP-ALL). We characterize 3D hubs as regulatory centers for oncogenes and disease markers, linking them to biological processes like cell division, inflammation, and stress response. Single-cell mapping reveals heterogeneous gene activation in discrete epigenetic clones, aiding in patient stratification for relapse risk after chemotherapy. Finally, we identify MYB as a 3D hub regulator in leukemia cells and show that the targeting of key regulators leads to hub dissolution, thereby providing a novel and effective anti-leukemic strategy. Overall, our work demonstrates the relevance of studying oncogenic 3D hubs to better understand cancer biology and tumor heterogeneity and to propose novel therapeutic strategies.

Keywords:  HiChIP; MYB; chromatin structure; heterogeneity; hubs; leukemia; modules; scATAC

DOI:  https://doi.org/10.1016/j.molcel.2024.11.040
Blood. 2024 Dec 27. pii: blood.2024026312. [Epub ahead of print]

Novel Treatment Strategies for Chronic Myeloid Leukemia.

Nataly Cruz-Rodriguez, Michael W Deininger.

Starting with imatinib, tyrosine kinase inhibitors (TKIs) have turned chronic myeloid leukemia (CML) from a lethal blood cancer into a chronic condition. As patients with access to advanced CML care have an almost normal life expectancy, there is a perception that CML is a problem of the past, and one should direct research resources elsewhere. However, a closer look at the current CML landscape reveals a more nuanced picture. Most patients still require life-long TKI therapy to avoid recurrence of active CML. Chronic TKI toxicity and the high costs of the well-tolerated agents remain challenging. Progression to blast phase still occurs, particularly in socioeconomically disadvantaged parts of the world, where high risk CML at diagnosis is common. Here we will review the prospects of further improving TKIs to achieve optimal suppression of BCR::ABL1 kinase activity, the potential of combining different classes of TKIs, and the current state of BCR::ABL1 degraders. We will cover combination therapy approaches to address TKI resistance in the setting of residual leukemia and in advanced CML. Despite the unprecedented success of TKIs in CML, more work is needed to truly finish the job, and we hope to stimulate innovative research aiming to achieve this goal.

DOI: https://doi.org/10.1182/blood.2024026312
Br J Haematol. 2024 Dec 25.

CPX-351 +/- gemtuzumab ozogamicin as induction therapy for adult patients with newly diagnosed, favourable-intermediate risk, FLT3-ITD negative, AML: A pilot study.

Chezi Ganzel, Avraham Frisch, Ofir Wolach, Yakir Moshe, Baher Krayem, Neta Dor, Etti Broide, Emmanuel Benayoun, Jacob M Rowe, Yishai Ofran.

  This pilot study evaluated CPX-351 in adults with newly diagnosed, favourable-intermediate risk, FLT3-ITD-negative AML. Twenty patients received CPX-351 for induction, with six also receiving gemtuzumab ozogamicin (GO). The complete response rate was 95%, with 42% achieving flow-based minimal residual disease (MRD) negativity post-induction. The 18-month leukaemia-free and overall survival estimates were 80% and 95% respectively. Adding GO appeared safe without prolonged cytopenias. Subclinical cardiotoxicity was observed in 25% of patients. The study demonstrated CPX-351's feasibility, with response and MRD-negativity rates comparable to standard '7 + 3' induction.

Keywords:  AML; CPX‐351; MRD; cardiotoxicity; gemtuzumab ozogamicin; vyxeos

DOI:  https://doi.org/10.1111/bjh.19967
Discov Med. 2024 Dec;36(191): 2313-2324

ALDH Enzymes and Hematological Diseases: A Scoping Review of Literature.

Amélie Foucault, Olivier Hérault.

  Aldehyde dehydrogenases (ALDHs) constitute a group of enzymes that catalyze the oxidation of aldehydes to carboxylic acids. The human ALDH superfamily, including 19 different isoenzymes (ALDH1A1, ALDH1A2, ALDH1A3, AHDH1B1, ALDH1L1, ALDH1L2, ALDH2, ALDH3A1, ALDH3A2, ALDH3B1, ALDH3B2, ALDH4A1, ALDH5A1, ALDH6A1, ALDH7A1, ALDH8A1, ALDH9A1, ALDHA16A1, ALDH18A1), displays different key physiological and toxicological functions, with specific tissue expression and substrate specificity. Several studies have established that ALDH are interesting markers for the identification and quantification of human hematopoietic stem cells and cancer stem cells, notably leukemic stem cells. ALDH2 is the best-documented enzyme, in this family, as having an impact on hematology, particularly myeloid malignancies. ALDH2 mainly catalyzes the detoxification of toxic aldehydes (acetaldehyde, formaldehyde). For example, ALDH2 detoxifies formaldehyde, which is produced during the differentiation of hematopoietic progenitors. The trigger of alcohol dehydrogenase 5 (also known as formaldehyde dehydrogenase or S-nitrosoglutathione reductase, ADH5/FDH/GSNOR)/ALDH2 allows to eliminate formaldehyde and ensures normal hematopoiesis. Moreover, the ALDH2*2 variant allele is the most frequent ALDH2 variant, found in 35-45% of individuals of East Asian origin. It is associated with altered acetaldehyde metabolism and is involved in several hematological diseases (aplastic anemia, bone marrow failure, myelodysplastic syndrome). This review presents current knowledge of different members of the ALDH family and their involvement in normal and malignant hematopoiesis. Focus was brought to the ALDH2 isoenzyme in congenital (Fanconi anemia, Aplastic anemia, mental retardation, and dwarfism (AMeD) syndrome, and idiopathic aplastic anemia) and acquired (acute myeloid leukemia and myelodysplastic syndrome) hematological diseases. It also describes the possibilities of using ALDH as both a biomarker and therapeutic target, to identify and eradicate leukemic stem cells in malignant diseases.

Keywords:  ALDH2 polymorphism; Fanconi anemia; biomarker; hematopoietic stem cell; leukemia

DOI:  https://doi.org/10.24976/Discov.Med.202436191.213
Exp Hematol. 2024 Dec 24. pii: S0301-472X(24)00562-9. [Epub ahead of print] 104698

Reconsidering the usual suspects in age-related hematologic disorders: is stem cell dysfunction a root cause of aging?

Foteini Fotopoulou, Esther Rodriguez-Correa, Charles Dussiau, Michael D Milsom.

  Aging exerts a profound impact on the hematopoietic system, leading to increased susceptibility to infections, autoimmune diseases, chronic inflammation, anemia, thrombotic events, and hematologic malignancies. Within the field of experimental hematology, the functional decline of hematopoietic stem cells (HSCs) is often regarded as a primary driver of age-related hematologic conditions. However, aging is clearly a complex multifaceted process involving not only HSCs but also mature blood cells and their interactions with other tissues. This review reappraises an HSC-centric view of hematopoietic aging by exploring how the entire hematopoietic hierarchy, from stem cells to mature cells, contributes to age-related disorders. It highlights the decline of both innate and adaptive immunity, leading to increased susceptibility to infections and cancer, and the rise of autoimmunity as peripheral immune cells undergo aging-induced changes. It explores the concept of "inflammaging," where persistent, low-grade inflammation driven by old immune cells creates a cycle of tissue damage and disease. Additionally, this review delves into the roles of inflammation and homeostatic regulation in age-related conditions such as thrombotic events and anemia, arguing that these issues arise from broader dysfunctions rather than stemming from HSC functional attrition alone. In summary, this review highlights the importance of taking a holistic approach to studying hematopoietic aging and its related pathologies. By looking beyond just stem cells and considering the full spectrum of age-associated changes, one can better capture the complexity of aging and attempt to develop preventative or rejuvenative strategies that better target multiple facets of this process.

Keywords:  CHIP; HSC; Hematopoietic stem cells; Inflammation; aging; anemia; clonal hematopoiesis; immune compromised; inflammaging; myeloid bias

DOI:  https://doi.org/10.1016/j.exphem.2024.104698
Blood Adv. 2024 Dec 27. pii: bloodadvances.2024014625. [Epub ahead of print]

Real-World Treatment Patterns and Healthcare Resource Use for Patients with Myelofibrosis: Results from the METER Study.

Vikas Gupta, Ciprian Tomuleasa, Gilberto Barranco, Hsin-An Hou, Grzegorz Helbig, Pankit Vachhani, Argiris Symeonidis, Ibrahim C Haznedaroglu, Kenny Galvez, Fernando Tatsch, Avijeet S Chopra, Meng Zhang, Tamas Vizkelety, Bryan C Murray, David M Ross.

Myelofibrosis (MF) is a myeloproliferative neoplasm that was most commonly treated with hydroxyurea (HU) prior to approval of ruxolitinib (RUX), now the standard of care. Factors that influence changes in MF treatment in real-world settings are not well understood. The METER study (NCT05444972) was a multi-country retrospective chart review of MF treatment patterns, treatment effectiveness, and healthcare resource utilization. Of 997 eligible patients, 65.9% had primary MF, and 11.7% were transfusion-dependent. The median (IQR) time from MF diagnosis to start of initial treatment (index date) was 29 (1-140) days. RUX was the most common first-line (1L) therapy (49.0%), followed by hydroxyurea (40.2%); 48.5% of patients remained on 1L therapy through Week 156. A total of 77 patients underwent allogeneic stem cell transplantation; use of transplantation was uncommon as 1L therapy and increased from 2.2% at Week 24 to 11.0% at Week 156 in patients 70 years of age. Median (95% CI) overall survival was 79.1 (70.8-non-estimable [NE]) months in all patients, 142.3 (74.1-NE) months for non-RUX patients, 77.6 (64.2-85.9) months for RUX 1L patients, and 72.6 (62.0-NE) months for RUX 2L+ patients. Of patients who experienced ≥1 corresponding event during the observational period, the median (IQR) hospital length of stay (LoS) (n=520), intensive care unit LoS (n=71), and number of transfusion events (n=375) were 16 (7-37) days, 5 (2-13) days, and 12 (4-26), respectively. Despite improvements, there was a high degree of hospitalization and transfusion events among these patients in routine practice. NCT05444972.

DOI: https://doi.org/10.1182/bloodadvances.2024014625
Br J Haematol. 2024 Dec 22.

Humanized anti-CD25 monoclonal antibody replaces methotrexate as acute graft-versus-host disease prophylaxis in haploidentical allogeneic haematopoietic stem cell transplantation.

Ao Zhang, Zhenli Huang, Ran Zhang, Ruowen Wei, Shan Jiang, Hongru Chen, Xiena Cao, Wei Shi, Linghui Xia, Yu Hu.

  Acute graft-versus-host disease (aGVHD) significantly affects quality of life and outcomes in patients post-haploidentical haematopoietic stem cell transplantation (haplo-HSCT). Methotrexate (MTX) is commonly used to prevent aGVHD but can lead to complications like delayed haematological recovery and oral mucositis (OM). This study investigates the efficacy of anti-CD25 monoclonal antibody (mAb) as a potential MTX alternative. Participants were divided into two cohorts: a single-dose group (25 mg/day anti-CD25 mAb with MTX) and a double-dose group (50 mg/day anti-CD25 mAb without MTX). The primary end-point was the cumulative incidence (CI) of severe aGVHD by day 100. The double-dose cohort demonstrated a significantly lower CI of total aGVHD (23.53% vs. 42.11%, p = 0.009) and grade 3-4 aGVHD (7.35% vs. 18.42%, p = 0.047). After inverse probability of treatment weighting adjustment, the adjusted HR of double-dose compared with single-dose cohort for total aGVHD was 0.47 (95% CI 0.26-0.86; p = 0.015), 0.42(95% CI 0.15-1.22; p = 0.110) for grade III-IV aGVHD, 0.45 (95% CI 0.26-0.77; p = 0.004) for total cGVHD and 0.36 (95% CI 0.18-0.72; p = 0.004) for the moderate to severe cGVHD. Additionally, this double-dose regimen significantly reduced the incidence of oral mucositis and demonstrated lower rates of infections and haemorrhagic cystitis. These findings suggest that a double-dose anti-CD25 mAb regimen without MTX is a promising strategy for aGVHD prophylaxis in haplo-HSCT (ChiCTR2200060184).

Keywords:  aGVHD prophylaxis; acute graft‐versus‐host disease; anti‐CD25 monoclonal antibody; haploidentical haematopoietic stem cell transplantation; methotrexate

DOI:  https://doi.org/10.1111/bjh.19958
Elife. 2024 Dec 23. pii: RP94884. [Epub ahead of print]13

A novel human pluripotent stem cell gene activation system identifies IGFBP2 as a mediator in the production of haematopoietic progenitors in vitro.

Paolo Petazzi, Telma Ventura, Francesca Paola Luongo, Heather McClafferty, Alisha May, Helen Alice Taylor, Michael J Shipston, Nicola Romanò, Lesley M Forrester, Pablo Menendez, Antonella Fidanza.

  A major challenge in the stem cell biology field is the ability to produce fully functional cells from induced pluripotent stem cells (iPSCs) that are a valuable resource for cell therapy, drug screening, and disease modelling. Here, we developed a novel inducible CRISPR-mediated activation strategy (iCRISPRa) to drive the expression of multiple endogenous transcription factors (TFs) important for in vitro cell fate and differentiation of iPSCs to haematopoietic progenitor cells. This work has identified a key role for IGFBP2 in developing haematopoietic progenitors. We first identified nine candidate TFs that we predicted to be involved in blood cell emergence during development, then generated tagged gRNAs directed to the transcriptional start site of these TFs that could also be detected during single-cell RNA sequencing (scRNAseq). iCRISPRa activation of these endogenous TFs resulted in a significant expansion of arterial-fated endothelial cells expressing high levels of IGFBP2, and our analysis indicated that IGFBP2 is involved in the remodelling of metabolic activity during in vitro endothelial to haematopoietic transition. As well as providing fundamental new insights into the mechanisms of haematopoietic differentiation, the broader applicability of iCRISPRa provides a valuable tool for studying dynamic processes in development and for recapitulating abnormal phenotypes characterised by ectopic activation of specific endogenous gene expression in a wide range of systems.

Keywords:  CRISPR activation; developmental biology; haematopoiesis; human; pluripotent stem cells; regenerative medicine; stem cells

DOI:  https://doi.org/10.7554/eLife.94884
Aging Cell. 2024 Dec 27. e14462

Effects of Aging on Glucose and Lipid Metabolism in Mice.

Evan C Lien, Ngoc Vu, Anna M Westermark, Laura V Danai, Allison N Lau, Yetiş Gültekin, Matthew A Kukurugya, Bryson D Bennett, Matthew G Vander Heiden.

  Aging is accompanied by multiple molecular changes that contribute to aging associated pathologies, such as accumulation of cellular damage and mitochondrial dysfunction. Tissue metabolism can also change with age, in part, because mitochondria are central to cellular metabolism. Moreover, the cofactor NAD+, which is reported to decline across multiple tissues during aging, plays a central role in metabolic pathways such as glycolysis, the tricarboxylic acid cycle, and the oxidative synthesis of nucleotides, amino acids, and lipids. To further characterize how tissue metabolism changes with age, we intravenously infused [U-13C]-glucose into young and old C57BL/6J, WSB/EiJ, and diversity outbred mice to trace glucose fate into downstream metabolites within plasma, liver, gastrocnemius muscle, and brain tissues. We found that glucose incorporation into central carbon and amino acid metabolism was robust during healthy aging across these different strains of mice. We also observed that levels of NAD+, NADH, and the NAD+/NADH ratio were unchanged in these tissues with healthy aging. However, aging tissues, particularly brain, exhibited evidence of upregulated fatty acid and sphingolipid metabolism reactions that regenerate NAD+ from NADH. These data suggest that NAD+-generating lipid metabolism reactions may help to maintain the NAD+/NADH ratio during healthy aging.

Keywords:  NAD; aging; metabolic rate; mice

DOI:  https://doi.org/10.1111/acel.14462
Hamostaseologie. 2024 Dec 21.

Molecular and Clinical Risk Factors Associated with Thrombosis and Bleeding in Myelofibrosis Patients.

Olga Morath, Carl Crodel, Jenny Rinke, Inken Sander, Aysun Tekbas, Manja Meggendorfer, Constance Baer, Andreas Hochhaus, Thomas Ernst.

BACKGROUND: The risk of thrombosis and bleeding in myelofibrosis (MF) has been historically underappreciated. We sought to investigate potential molecular and clinical risk factors for venous (VTE) and arterial (ATE) thrombotic events as well as bleeding episodes.
METHODS: Data from 246 consecutive MF patients were analyzed. Driver mutations were tested in 191 patients.
RESULTS: In total, 181 mutations were found in 177 MF patients: 118 (61.8%) patients showed JAK2-V617F, 50 patients (26.2%) showed CALR, and 6 patients (3.1%) showed MPL mutations. Two patients were JAK2-V617F and MPL positive and one patient was positive for all three genes. Fourteen (7.3%) patients were triple negative. The JAK2-V617F allele burden was assessed in 63 JAK2-V617F-mutated patients, revealing a median of 35.6% (range: 5.0-96.0). At the time of MF diagnosis and during follow-up, 84 thrombotic events (52 VTEs and 32 ATEs) were observed, corresponding to 6.6% of patients per year. A significant association was found between JAK2-V617F mutation (OR: 2.5, 95% CI: 1.1-5.6) and prior VTE (OR: 7.6, 95% CI: 2.1-27.1) with an increased risk of VTE. Patients with prefibrotic MF had a higher rate of ATE than patients with overt MF. Hemorrhagic events occurred in 34 (13.8%) patients, corresponding to 3.8% of patients per year. Fibrosis grade 3 was associated with bleeding risk (OR: 3.4, 95% CI: 1.2-9.2, p = 0.02).
CONCLUSIONS: The presence of the JAK2-V617F mutation, regardless of allele burden, and prior thrombosis were strongly associated with an increased risk of VTE. Patients with prefibrotic MF might be considered at high risk for developing ATE.

DOI: https://doi.org/10.1055/a-2410-8530