16792 results for "sec+and+unspecified+malignant+neoplasm"

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• Somatic mutations reveal lineage relationships and age-related mutagenesis in human hematopoiesis

  Mutation accumulation during human life can contribute to hematopoietic dysfunction; however, the underlying dynamics are unknown. Somatic mutations in blood progenitors can provide insight into the rate and processes underlying this accumulation, as well as the developmental lineage tree and stem cell division numbers. Here, we catalogue somatic mutations in the genomes of human bone marrow-derived and cord blood-derived hematopoietic stem and multipotent progenitor cells (HSPCs) and find that base substitutions accumulate with approximately 17 base substitutions per year in both populations, while insertions and deletions occur sporadically and at low numbers. The majority of mutations in adult HSPCs were acquired after birth and could be explained by the constant activity of various endogenous processes, which also explains the mutation load in acute myeloid leukemia (AML). We construct a developmental lineage tree revealing a polyclonal architecture of the hematopoietic progenitor compartment and providing evidence that developmental clones exhibit multipotency, though lineage biases can be detected. Our approach highlights novel features of human native hematopoiesis and its implications for leukemogenesis.

  Study EGAS00001003068

• WGS of T-cell and NK-cell lymphoma for ICGC (NKTL-SG)

  Lymphomas are malignancies originating from the lymphatic system and there is a worldwide significant increase in incidences of this cancer. Lymphomas can be further classified into 2 categories namely Hodgkin’s (HL), and Non-Hodgkin’s lymphoma (NHL). The latter can be divided further into B, T and NK cell NHL. Peripheral T-cell lymphoma (PTCL) and Natural Killer/ T-cell lymphoma (NKTL) arise from mature T lymphocytes and NK cells. The more common subtypes include NKTL, PTCL not-otherwise-specified (PTCL-NOS), systemic anaplastic large cell lymphoma (ALCL), follicular PTCL (F-PTCL), angioimmunoblastic T-cell lymphoma (AITL) and enteropathy-associated T-cell lymphoma (EATL). Whole genome analyses on T-cell and NK-cell lymphoma samples from various countries to gain a better understanding of the pathogenesis and biology of these tumors. The comprehensive profiling and comparison among patients from various countries with different etiopathogenesis will hopefully facilitate the elucidation of key pathways and underlying molecular mechanisms driving these cancers, opening up novel therapeutic strategies in the future.

  Study EGAS00001002398

• Genetic and Functional Drivers of Diffuse Large B Cell Lymphoma

  Diffuse large B cell lymphoma (DLBCL) is the most common hematologic malignancy and is characterized by a striking degree of heterogeneity. We enrolled a total of 1001 DLBCL patients and comprehensively defined the landscape of genetic mutations, copy number alterations and expression through whole-exome and transcriptome sequencing. We identified 150 genetic drivers of DLBCL including many novel, clinically relevant genes (e.g. SPEN, SETD1B and KLHL14). Genetic drivers were highly enriched among essential genes identified by CRISPR screening in DLBCL cell lines including those of immediate potential therapeutic relevance such as MTOR, SYK, SF3B1 and XPO1. RHOA emerged as a critical driver gene from our genetic analysis and CRISPR screen; we further delineated its functional role in vitro and in vivo models to define its role as an essential oncogene in DLBCL. Our work thus identifies the functional landscape of genetic drivers and their clinical and therapeutic relevance in DLBCL patients.

  Study EGAS00001002606

• atrial appendage RNA-seq in non-, paroxysmal and persistent atrial fibrillation

  Understanding the interconnectedness of structural remodelling processes atrial fibrillation (AF) in patients could identify targets for future therapies. These data include transcriptome sequencing of atrial tissues of patients without AF, with paroxysmal AF and persistent AF (total n=64). In AF patients, epicardial cell gene expression decreased, contrasting with an upregulation of epithelial to mesenchymal transition (EMT) and mesenchymal cell gene expression. Immunohistochemistry demonstrated thickening of the epicardium and an increased proportion of (myo)fibroblast-like cells in the myocardium, supporting enhanced EMT in AF. We furthermore report an upregulation of endothelial cell proliferation, angiogenesis and endothelial signalling. EMT and endothelial cell proliferation concurred with increased interstitial (myo)fibroblast-like cells and extracellular matrix gene expression including enhanced tenascin-c, thrombospondins, biglycan and versican. Morphological analysis discovered increased and redistributed glycosaminoglycans and collagens in the atria of AF patients. Signalling pathways, including cell-matrix interactions, PI3K-AKT and Notch signalling, that could regulate mesenchymal cell activation, were upregulated. These dynamic processes may provide targets to prevent or reverse structural remodelling.

  Study EGAS00001005295

• Multi-omic analysis of cell-of-origin and epigenomic state in pediatric H3K27M gliomas

  It is not known whether midline pediatric gliomas driven by Histone 3 K27M mutations (oncohistones) or EZHIP expression (oncohistone-mimics) share a common cell-of-origin, or arise from distinct cell types with unique vulnerabilities to PRC2 inhibition and partner alterations. Here, we define the etiological and oncogenic relationship between pediatric midline gliomas characterized by inhibition of K27M and K27M-like oncohistones. We assemble an extensive reference for gliogenesis from the developing mouse and human fetal brain. With bulk and single-cell transcriptomics and epigenomics, we profiled a large cohort of primary tumors comprising H3.1K27M and H3.3K27M pontine gliomas, H3.3K27M thalamic gliomas, and EZHIP+ posterior fossa ependymomas. We focus on differences across axes of location (thalamus vs. pons vs. posterior fossa), tumor type (diffuse midline gliomas vs. ependymomas), and oncohistone (H3.1/2K27M vs. H3.3K27M vs. EZHIP). We use tumor molecular features to delineate transcriptional states and cell-of-origin in each entity. Finally, we use culture models in isogenic contexts to interrogate the effect of each oncohistone or mimic.

  Study EGAS00001005773

• Intratumoral Heterogeneity and Clonal Evolution Induced by HPV Integration.

  The human papillomavirus (HPV) genome is integrated into host DNA in most HPV-positive cancers, but the consequences for chromosomal integrity are unknown. Continuous long-read sequencing of oropharyngeal cancers and cancer cell lines revealed a unique form of structural variation, termed heterocateny here, characterized by heterogeneous, interrelated, and repetative patterns of concatemerized virus and host DNA segments. Evidence of heterocateny was detected in extrachromosomal and/or intrachromosomal DNA in all cases. Unique breakpoint sequences shared across structurally heterogeneous virus-host concatemers within each cancer facilitated stepwise reconstruction of their evolution from a common molecular ancestor. This analysis revealed that unstable virus and virus-host concatemers in ecDNA or integrated form mediate insertion into and excision from chromosomes, capture, rearrangement, and rolling-circle amplification of host DNA, and chromosomal rearrangements. The data indicate that heterocatena is driven by the dynamic, aberrant replication and recombination of an oncogenic DNA virus, thereby extending known consequences of HPV integration to include promotion of intra-tumoral heterogeneity and clonal evolution.

  Study EGAS00001006652

• NHLBI TOPMed: Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE)

  ECLIPSE was a longitudinal observational study of 2164 COPD subjects and a smaller number of smoking controls (337) and nonsmoking controls (245) followed regularly for three years, with three chest CT scans (at baseline, one year, and three years) (Vestbo et al., 2008, PMID: 18216052). Subjects were enrolled at clinical centers in the US, Canada, Europe, and New Zealand. Inclusion criteria included subjects ages 40-75, at least 10 pack-years of smoking, and spirometry in GOLD grades 2-4 (COPD cases) or normal spirometry with post-bronchodilator FEV1 >85% (predicted) and FEV1/FVC>0.7 (controls). Study visits were performed at enrollment, three months, and every six months thereafter with spirometry, questionnaires, and other clinical evaluations. The ECLIPSE CT scans have been analyzed with the VIDA software for emphysema and airway phenotypes. ECLIPSE has provided key insights into the clinical epidemiology of COPD, including COPD exacerbations (Hurst, et. al., 2010, PMID: 20843247) and lung function decline in COPD (Vestbo, et. al., 2011, PMID: 21991892). ECLIPSE has been used in a number of genetic studies of COPD susceptibility and protein biomarkers (Faner, et. al., 2014, PMID: 24310110). Genome-wide gene expression microarray data are available in 147 induced sputum samples from COPD subjects and 248 peripheral blood samples from COPD and control subjects. Phenotype data for ECLIPSE subjects is available through dbGaP phs001252.

  Study phs001472

• RBMX functional retrocopy safeguards brain development

  Retrotransposition has generated thousands of intronless gene copies in mammalian genomes, yet their contribution to brain development and evolution remains largely unexplored. We investigated the role for RBMX retrocopy in shaping neurodevelopment and modulating disease. First, we reported 8 distinct pathogenic variants in RBMX, an X-linked splicing regulator, in 11 males presenting with intellectual disability, microcephaly, and cortical malformations. Then, we combined transcriptomic profiling, protein–protein and protein–RNA interaction studies both in human cellular models and mouse embryonic cortices to assess the functional redundancy between RBMX and its retrocopy RBMXL1. Finally, we use mouse genetics to dissect RBMX function and its compensation by RBMXL1 in corticogenesis. We show that RBMX pathogenic variants disrupt cortical development through both loss- and gain-of-function mechanisms. Surprisingly, despite severe phenotypes in humans, Rbmx-deficient mice display only mild cortical abnormalities, a discrepancy likely due to compensation by Rbmxl1, a retrocopy that arose independently in mice and humans. We demonstrate that RBMX and RBMXL1 share protein and RNA partners and act redundantly in brain development, with RBMXL1 buffering the impact of RBMX deficiency. Together, these findings establish that RBMXL1 functions as a functional paralog of RBMX safeguarding neurodevelopment by buffering deleterious variation. More broadly, these results identify retrocopies as active contributors to neurodevelopmental robustness and suggest that functional retrocopies may have facilitated the evolutionary diversification of the mammalian brain.

  Study EGAS50000001650

• Driver mutations in histone H3.3 and chromatin remodelling genes in paediatric glioblastoma

  Glioblastoma multiforme (GBM) is a lethal brain tumour in adults and children. However, DNA copy number and gene expression signatures indicate differences between adult and paediatric cases. To explore the genetic events underlying this distinction, we sequenced the exomes of 48 paediatric GBM samples. Somatic mutations in the H3.3-ATRX-DAXX chromatin remodelling pathway were identified in 44% of tumours (21/48). Recurrent mutations in H3F3A, which encodes the replication-independent histone 3 variant H3.3, were observed in 31% of tumours, and led to amino acid substitutions at two critical positions within the histone tail (K27M, G34R/G34V) involved in key regulatory post-translational modifications. Mutations in ATRX (alpha-thalassaemia/mental retardation syndrome X-linked) and DAXX (death-domain associated protein), encoding two subunits of a chromatin remodelling complex required for H3.3 incorporation at pericentric heterochromatin and telomeres, were identified in 31% of samples overall, and in 100% of tumours harbouring a G34R or G34V H3.3 mutation. Somatic TP53 mutations were identified in 54% of all cases, and in 86% of samples with H3F3A and/or ATRX mutations. Screening of a large cohort of gliomas of various grades and histologies (n=784) showed H3F3A mutations to be specific to GBM and highly prevalent in children and young adults. Furthermore, the presence of H3F3A/ATRX-DAXX/TP53 mutations was strongly associated with alternative lengthening of telomeres and specific gene expression profiles. This is, to our knowledge, the first report to highlight recurrent mutations in a regulatory histone in humans, and our data suggest that defects of the chromatin architecture underlie paediatric and young adult GBM pathogenesis.

  Study EGAS00001000226

• Integrated genomic analyses reveal molecular correlates of clinical response and resistance to atezolizumab in combination with bevacizumab in advanced hepatocellular carcinoma

  Atezolizumab (anti–programmed death-ligand 1 [anti-PD-L1]) and bevacizumab (anti-vascular endothelial growth factor [anti-VEGF]) combination therapy has become the new standard of care in patients with unresectable hepatocellular carcinoma. However, potential predictive biomarkers and mechanisms of response and resistance remain less understood. We report integrated molecular analyses of tumor samples from 358 patients enrolled in the GO30140 phase 1b or IMbrave150 phase 3 trials who were treated with atezolizumab combined with bevacizumab, atezolizumab alone, or sorafenib. Pre-existing immunity assessed by high expression of CD274 (PD-L1 mRNA), T-effector signature, and intratumoral CD8+ T cell density were associated with response and better clinical outcomes with the combination treatment. Less clinical benefit was associated with high regulatory T cell (Treg) to effector T-cell ratio and high expression of oncofetal genes such as GPC3 and AFP. Improved outcomes from the combination vs atezolizumab alone appeared to be associated with high expression of KDR (VEGFR2), Treg, and myeloid inflammation signatures, indicating anti-VEGF may contribute by targeting these axes. These findings were further validated by transcriptome analysis of paired pre- and post-treatment biopsies, in situ analysis by multiplex IHC and digital pathology, and in vivo study of an immunogenic hepatocellular carcinoma mouse model. Our findings highlight that anti-VEGF therapy might augment antitumor immunity and enhance anti–PD-L1 immunotherapy by targeting VEGF-mediated angiogenesis, Treg proliferation, and myeloid cell inflammation. Furthermore, our study identified candidate biomarkers for predicting response and resistance to anti–PD-L1 and anti-VEGF combination therapy.

  Study EGAS00001005503