Publications by authors named "Nimer S"

Article Synopsis
  • 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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Article Synopsis
  • 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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SETD2 is the only enzyme responsible for transcription-coupled histone H3 lysine 36 trimethylation (H3K36me3). Mutations in SETD2 cause human diseases including cancer and developmental defects. In mice, Setd2 is essential for embryonic vascular remodeling.

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  • SF3B1 mutations are common in cancer but lack directed treatments. Recent trials of XPO1 inhibitors in high-risk myelodysplastic neoplasms (MDS) found that patients with these mutations respond better to treatment.
  • The study explores how these mutations affect RNA behavior when XPO1 is inhibited, leading to altered splicing and activation of apoptotic pathways in the mutant cells.
  • Researchers identified that combining eltanexor (an XPO1 inhibitor) with venetoclax (a BCL2 inhibitor) effectively targets SF3B1 mutant cells while minimizing toxicity, paving the way for new treatment strategies for high-risk MDS.
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SARS-CoV-2 is a virus that affects the human immune system. It was observed to be on the rise since the beginning of 2020 and turned into a life-threatening pandemic. Scientists have tried to develop a possible preventive and therapeutic drug against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and other related coronaviruses by assessing COVID-19-recovered persons' immunity.

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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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An important epigenetic component of tyrosine kinase signaling is the phosphorylation of histones, and epigenetic readers, writers, and erasers. Phosphorylation of protein arginine methyltransferases (PRMTs), have been shown to enhance and impair their enzymatic activity. In this study, we show that the hyperactivation of Janus kinase 2 (JAK2) by the V617F mutation phosphorylates tyrosine residues (Y149 and Y334) in coactivator-associated arginine methyltransferase 1 (CARM1), an important target in hematologic malignancies, increasing its methyltransferase activity and altering its target specificity.

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Article Synopsis
  • - The study explores how dendritic cells (DCs), important immune cells, develop under the influence of the growth factor Flt3 ligand (Flt3L) and its receptor, using CRISPR-Cas9 technology for genetic analysis.
  • - Genome screenings revealed several key regulators of DC differentiation, highlighting the roles of TSC and GATOR1 complexes in controlling progenitor growth and enabling DC development through mTOR signaling inhibition.
  • - The transcriptional repressor Trim33 was identified as crucial for DC differentiation; its absence led to a significant decrease in DC progenitors and specific types of DCs, while promoting the expression of genes related to inflammation rather than DC development.
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Study Objective: Studies have demonstrated sodium-glucose cotransporter-2 (SGLT2) inhibitors are kidney protective; however, their ability to cause hemodynamic changes may predispose patients to acute kidney injury (AKI). An FDA warning recommends evaluating for factors that predispose patients to AKI before initiating a SGLT2 inhibitor. The primary objective of this study is to identify risk factors that may predispose persons with diabetes to AKI when initiating SGLT2 inhibitor therapy.

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ASXL1 mutation frequently occurs in all forms of myeloid malignancies and is associated with aggressive disease and poor prognosis. ASXL1 recruits Polycomb repressive complex 2 (PRC2) to specific gene loci to repress transcription through trimethylation of histone H3 on lysine 27 (H3K27me3). ASXL1 alterations reduce H3K27me3 levels, which results in leukemogenic gene expression and the development of myeloid malignancies.

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Article Synopsis
  • - 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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Bromodomain-containing protein 4 (BRD4) is overexpressed and functionally implicated in various myeloid malignancies. However, the role of BRD4 in normal hematopoiesis remains largely unknown. Here, utilizing an inducible Brd4 knockout mouse model, we find that deletion of Brd4 (Brd4 ) in the hematopoietic system impairs hematopoietic stem cell (HSC) self-renewal and differentiation, which associates with cell cycle arrest and senescence.

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During emergency hematopoiesis, hematopoietic stem cells (HSCs) rapidly proliferate to produce myeloid and lymphoid effector cells, a response that is critical against infection or tissue injury. If unresolved, this process leads to sustained inflammation, which can cause life-threatening diseases and cancer. Here, we identify a role of double PHD fingers 2 (DPF2) in modulating inflammation.

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Over the course of the COVID-19 pandemic, SARS-CoV-2 variants of concern (VOCs) with increased transmissibility and immune escape capabilities, such as Delta and Omicron, have triggered waves of new COVID-19 infections worldwide, and Omicron subvariants continue to represent a global health concern. Tracking the prevalence and dynamics of VOCs has clinical and epidemiological significance and is essential for modeling the progression and evolution of the COVID-19 pandemic. Next generation sequencing (NGS) is recognized as the gold standard for genomic characterization of SARS-CoV-2 variants, but it is labor and cost intensive and not amenable to rapid lineage identification.

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TET2 haploinsufficiency is a driving event in myeloid cancers and is associated with a worse prognosis in patients with acute myeloid leukemia (AML). Enhancing residual TET2 activity using vitamin C increases oxidized 5-methylcytosine (mC) formation and promotes active DNA demethylation via base excision repair (BER), which slows leukemia progression. We utilize genetic and compound library screening approaches to identify rational combination treatment strategies to improve use of vitamin C as an adjuvant therapy for AML.

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Patients treated with cytotoxic therapies, including autologous stem cell transplantation, are at risk for developing therapy-related myeloid neoplasms (tMN). Preleukemic clones (ie, clonal hematopoiesis [CH]) are detectable years before the development of these aggressive malignancies, although the genomic events leading to transformation and expansion are not well defined. Here, by leveraging distinctive chemotherapy-associated mutational signatures from whole-genome sequencing data and targeted sequencing of prechemotherapy samples, we reconstructed the evolutionary life-history of 39 therapy-related myeloid malignancies.

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Objectives: Patient education resources that address barriers to health literacy to improve understanding and outcomes in myelodysplastic syndromes (MDS) are limited. The aim of this study was to evaluate the impact and outcomes benefits of cancer educational modules (which includes the 'You and MDS' website and YouTube hosted resources) related to MDS education, awareness, understanding and health outcomes.

Methods: This was a retrospective study of learner feedback, metrics, and utilization data from July 2018 to August 2021.

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Innate immune cells participate in the detection of tumor cells via complex signaling pathways mediated by pattern-recognition receptors, such as Toll-like receptors and nucleotide-binding and oligomerization domain-like receptors. These pathways are finely tuned via multiple mechanisms, including epigenetic regulation. It is well established that hematopoietic progenitors generate innate immune cells that can regulate cancer cell behavior, and the disruption of normal hematopoiesis in pathologic states may lead to altered immunity and the development of cancer.

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Diverse DNA structures occur as reaction intermediates in various DNA-damage and -repair mechanisms, most of which results from replication stress. We harness the power of proteins evolutionarily optimized to bind and "trap" specific DNA reaction-intermediate structures, to quantify the structures, and discern the mechanisms of their occurrence in cells. The engineered proteins also allow genomic mapping of sites at which specific DNA structures occur preferentially, using a structure-trapping protein and ChIP-seq- or Cut-and-Tag-like methods.

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Myelodysplastic syndromes (MDS) are hematopoietic stem and progenitor cell (HSPC) malignancies characterized by ineffective hematopoiesis and an increased risk of leukemia transformation. Epigenetic regulators are recurrently mutated in MDS, directly implicating epigenetic dysregulation in MDS pathogenesis. Here, we identified a tumor suppressor role of the acetyltransferase p300 in clinically relevant MDS models driven by mutations in the epigenetic regulators TET2, ASXL1, and SRSF2.

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INTS11, the catalytic subunit of the Integrator (INT) complex, is crucial for the biogenesis of small nuclear RNAs and enhancer RNAs. However, the role of INTS11 in hematopoietic stem and progenitor cell (HSPC) biology is unknown. Here, we report that INTS11 is required for normal hematopoiesis and hematopoietic-specific genetic deletion of leads to cell cycle arrest and impairment of fetal and adult HSPCs.

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The activity of Rho family GTPase protein, RAC1, which plays important normal physiological functions, is dysregulated in multiple cancers. RAC1 is expressed in both estrogen receptor alpha (ER)-positive and ER-negative breast cancer (BC) cells. However, ER-positive BC is more sensitive to RAC1 inhibition.

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Mitogen-activated protein kinases (MAPKs) are inactivated by dual-specificity phosphatases (DUSPs), the activities of which are tightly regulated during cell differentiation. Using knockdown screening and single-cell transcriptional analysis, we demonstrate that DUSP4 is the phosphatase that specifically inactivates p38 kinase to promote megakaryocyte (Mk) differentiation. Mechanistically, PRMT1-mediated methylation of DUSP4 triggers its ubiquitinylation by an E3 ligase HUWE1.

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