Publications by authors named "Bejar R"

This article reports preclinical development of TUS, an oral kinase inhibitor currently in clinical development for treatment of AML. The article covers the studies of TUS activities on cellular targets and the nonclinical studies that supported the advancement of TUS to a phase I/II trial of TUS/VEN in refractory AML and a phase I/II trial of TUS/VEN/5-azacytidine in newly diagnosed patients with AML (NCT03850574).

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  • Current chromatin analysis methods struggle with complex tissues, prompting the development of Droplet Hi-C, a new technique using microfluidics for high-throughput, single-cell profiling.
  • Droplet Hi-C allowed researchers to map chromatin structures in mouse cortex and assess gene regulation in various cortical cell types, as well as identify genetic changes in human cancers.
  • The technique also combines chromatin and transcriptome profiling in single cells, improving insights into the relationship between chromatin architecture and gene expression in both healthy and tumor tissues.*
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  • The WHO and International Consensus Classification 2022 aim to improve diagnosis and treatment decisions for myelodysplastic syndromes, but disparities in their implementation exist.
  • A panel of experts used a data-driven method and the Delphi consensus process to align the two classifications, focusing on genomic features to create harmonized labels for distinct clusters.
  • Key findings identified nine genomic clusters, with the most significant linked to biallelic TP53 inactivation, and highlighted the inadequacy of traditional morphological assessments in capturing the complexity of these diseases.
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  • Myelodysplastic neoplasms/syndromes (MDS) are a diverse set of diseases marked by ineffective blood cell production.
  • Recent classification systems by the World Health Organization and the International Consensus have provided more detailed categorizations of MDS based on morphology and genetics.
  • A comprehensive and systematic approach is essential for the accurate diagnosis and classification of MDS, as outlined by the International Consortium for MDS (icMDS).
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  • Myelodysplastic syndromes (MDS) are blood disorders marked by irregularities in myeloid cells and low blood cell counts, often caused by genetic mutations, though classification has mostly focused on cell appearance.
  • A study analyzing genomic data from over 3,200 MDS patients identified 16 distinct molecular subtypes, revealing varied clinical outcomes, with the majority of patients (86%) fitting into specific genetic groups linked to different survival rates.
  • The findings suggest that understanding these genetically defined subgroups can enhance MDS classification and inform future treatment strategies, emphasizing the importance of genetic insight in managing the disease.
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Notable treatment advances have been made in recent years for patients with myelodysplastic syndromes/neoplasms (MDS), and several new drugs are under development. For example, the emerging availability of oral MDS therapies holds the promise of improving patients' health-related quality of life (HRQoL). Within this rapidly evolving landscape, the inclusion of HRQoL and other patient-reported outcomes (PROs) is critical to inform the benefit/risk assessment of new therapies or to assess whether patients live longer and better, for what will likely remain a largely incurable disease.

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Comprehensive analysis of chromatin architecture is crucial for understanding the gene regulatory programs during development and in disease pathogenesis, yet current methods often inadequately address the unique challenges presented by analysis of heterogeneous tissue samples. Here, we introduce Droplet Hi-C, which employs a commercial microfluidic device for high-throughput, single-cell chromatin conformation profiling in droplets. Using Droplet Hi-C, we mapped the chromatin architecture at single-cell resolution from the mouse cortex and analyzed gene regulatory programs in major cortical cell types.

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  • Mutations in the UBA1 gene, which are linked to VEXAS syndrome, have been found in patients with myelodysplastic syndromes (MDS), with a study identifying 7% of a cohort having specific UBA1 mutations.
  • An additional sequencing analysis of a larger group revealed 1% with other potentially harmful variants, and all 40 identified patients with likely/pathogenic mutations were male with various MDS subtypes.
  • Most patients with UBA1 mutations exhibited symptoms consistent with VEXAS syndrome, suggesting that routine screening for UBA1 mutations should be considered in MDS management.
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Myelodysplastic syndromes (MDS) are a group of incurable hematopoietic stem cell (HSC) neoplasms characterized by peripheral blood cytopenias and a high risk of progression to acute myeloid leukemia. MDS represent the final stage in a continuum of HSCs' genetic and functional alterations and are preceded by a premalignant phase, clonal cytopenia of undetermined significance (CCUS). Dissecting the mechanisms of CCUS maintenance may uncover therapeutic targets to delay or prevent malignant transformation.

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  • - The International Consortium for MDS has updated guidelines on classification, prognostication, and response assessment for myelodysplastic syndromes/neoplasms (MDS), focusing on recent changes in the WHO and ICC classifications.
  • - The report compares traditional risk assessment tools with newer molecular approaches, addressing the limitations of existing criteria in measuring treatment effectiveness.
  • - Emphasizing patient-centered care, the review highlights the importance of quality-of-life assessments and presents how the latest IWG response criteria improve the evaluation of therapeutic outcomes.
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Myelodysplastic neoplasms (MDS) are a collection of hematopoietic disorders with widely variable prognoses and treatment options. Accurate pathologic diagnoses present challenges because of interobserver variability in interpreting morphology and quantifying dysplasia. We compared local clinical site diagnoses with central, adjudicated review from 918 participants enrolled in the ongoing National Heart, Lung, and Blood Institute National MDS Natural History Study, a prospective observational cohort study of participants with suspected MDS or MDS/myeloproliferative neoplasms (MPNs).

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The National Heart, Lung, and Blood Institute-funded National MDS Natural History Study (NCT02775383) is a prospective cohort study enrolling patients with cytopenia with suspected myelodysplastic syndromes (MDS) to evaluate factors associated with disease. Here, we sequenced 53 genes in bone marrow samples harvested from 1298 patients diagnosed with myeloid malignancy, including MDS and non-MDS myeloid malignancy or alternative marrow conditions with cytopenia based on concordance between independent histopathologic reviews (local, centralized, and tertiary to adjudicate disagreements when needed). We developed a novel 2-stage diagnostic classifier based on mutational profiles in 18 of 53 sequenced genes that were sufficient to best predict a diagnosis of myeloid malignancy and among those with a predicted myeloid malignancy, predict whether they had MDS.

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  • Recent research on myelodysplastic syndromes (MDS) is advancing our understanding of their biological causes and leading to new treatment strategies.
  • The first International Workshop on MDS highlighted discoveries related to genetics, immune system dysfunction, and how MDS develops from clonal hematopoiesis.
  • While new therapies targeting specific molecular issues have been developed and tested in clinical trials, none have yet received approval, emphasizing the need for further research to personalize MDS treatment.
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Evaluating response to treatment in MDS represents a major challenge due to its associated complexity and heterogeneity. Although response criteria have been proposed by the IWG and revised on several occasions, these criteria have limitations. This review has outlined some refinements that can be used to improve response assessment and to ensure the identification of clinically meaningful endpoints.

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Myelodysplastic syndromes (MDSs) are a heterogeneous group of hematologic malignancies with a propensity to progress to acute myeloid leukemia. Causal mutations in multiple classes of genes have been identified in patients with MDS with some patients harboring more than 1 mutation. Interestingly, double mutations tend to occur in different classes rather than the same class of genes, as exemplified by frequent cooccurring mutations in the transcription factor RUNX1 and the splicing factor SRSF2.

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Therapeutic options for myelodysplastic syndromes (MDS) are highly risk stratified, with more toxic treatments reserved for patients at higher risk and more supportive approaches favored for those with lower-risk disease. The hypomethylating agents azacitidine (AZA) and decitabine (DEC) are recommended as first-line therapy for higher-risk MDS; for lower-risk disease, the focus is primarily on treating symptomatic anemia with hematopoietic growth factors, luspatercept, or lenalidomide.

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  • * Conventional cytogenetics has been a key method for identifying chromosomal abnormalities, but newer sequencing technologies like whole-genome sequencing offer more detailed detection of both somatic and germline mutations.
  • * The 2022 International Consensus Classification heavily incorporates genomic data to enhance diagnosis and treatment personalization, aiming to aid healthcare professionals in utilizing genomic testing effectively for better patient outcomes.
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  • * The study reveals three main differentiation trajectories for CMML cells: monocytic, megakaryocyte-erythroid progenitor (MEP), and normal-like, with the monocytic trajectory linked to negative outcomes and increased inflammation.
  • * Hypomethylating agents can reduce monocytic-biased cells, and the research suggests that understanding these different states and their responses to therapies could lead to better treatments for patients with CMML and similar conditions.
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Deleterious somatic mutations in DNA methyltransferase 3 alpha (DNMT3A) and TET mehtylcytosine dioxygenase 2 (TET2) are associated with clonal expansion of hematopoietic cells and higher risk of cardiovascular disease (CVD). Here, we investigated roles of DNMT3A and TET2 in normal human monocyte-derived macrophages (MDM), in MDM isolated from individuals with DNMT3A or TET2 mutations, and in macrophages isolated from human atherosclerotic plaques. We found that loss of function of DNMT3A or TET2 resulted in a type I interferon response due to impaired mitochondrial DNA integrity and activation of cGAS signaling.

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  • * Researchers found that SF3B1 mutations activate the EIF2AK1 pathway due to heme deficiency, and targeting this pathway can improve red blood cell maturation in MDS-RS patients.
  • * The findings suggest that developing EIF2AK1 inhibitors could provide new treatment options for MDS-RS patients, reducing their reliance on blood transfusions and addressing iron overload from frequent transfusions.
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