22950 results for "ega"

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• 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

• Circulating Tumor DNA Analysis Detects Minimal Residual Disease and Predicts Recurrence in Patients with Stage II Colon Cancer

  Detection of circulating tumor DNA (ctDNA) after resection of stage II colon cancer may identify those at the highest risk of recurrence and help inform adjuvant treatment decisions. We used massively-parallel-sequencing–based assays to evaluate the ability of ctDNA to detect minimal residual disease in 1046 plasma samples from a prospective cohort of 230 patients with resected stage II colon cancer. In patients not treated with adjuvant chemotherapy, ctDNA was detected post-operatively in 14 of 178 (7.9%) patients, 11 (79%) of whom had recurred at a median follow-up of 27 months; recurrence occurred in only 16 (9.8 %) of the 164 patients with negative ctDNA (HR, 18; 95% confidence interval [CI], 7.9 to 36; P<0.001). In patients treated with chemotherapy, the presence of ctDNA following completion of chemotherapy was also associated with an inferior recurrence-free survival (HR, 11; 95% CI, 1.8 to 68; P=0.001). ctDNA detection after stage II colon cancer resection provides direct evidence of residual disease and identifies patients at very high risk of recurrence.

  Study EGAS00001001839

• HCA_Placental_Infection_Atlas

  HCA Placental Infection Atlas Self-renewing human trophoblast stem cells (hTSC) can give rise to major trophoblast lineages, including syncytiotrophoblast (SCT) and extravillous trophoblast (EVT). hTSC has facilitated the study of placental development and function in vitro. Here, we aim to utilise the hTSC line (HMDMC 20/0005) to study human placental infection and inflammation. This study will provide the opportunity to better understand the pathogenesis of human placenta in the event of infection and inflammation. In brief, differentiated hTSC will be infected with relevant pathogens and stimulated with a panel of inflammatory cytokines. We will use single-cell genomic and spatial approaches to characterise cellular heterogeneity in response to infection or cytokines stimulus. In parallel, we will investigate the interaction between iPSC-derived macrophages with different trophoblast lineages during the course of infection using single-cell genomic and spatial methods. This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/

  Study EGAS00001004722

• Reference exome data for Australian Aboriginal populations to support health-based research

  Whole exome sequencing (WES) is a popular and successful technology which is widely used in both research and clinical settings. However, there is a paucity of reference data for Aboriginal Australians to underpin the translation of health-based genomic research. Here we provide a catalogue of variants called after sequencing the exomes of 50 Aboriginal individuals from the Northern Territory (NT) of Australia and compare these to 72 previously published exomes from a Western Australian (WA) population of Martu origin. Sequence data for both NT and WA samples were processed using an ‘intersect-then-combine’ (ITC) approach, using GATK and SAMtools to call variants. A total of 289,829 variants were identified in at least one individual in the NT cohort and 248,374 variants in at least one individual in the WA cohort. Of these, 166,719 variants were present in both cohorts, whilst 123,110 variants were private to the NT cohort and 81,655 were private to the WA cohort. Our data set provides a useful reference point for genomic studies on Aboriginal Australians.

  Study EGAS00001003745

• Clonal expansion and epigenetic reprogramming following deletion or amplification of mutant IDH1

  IDH1 mutation is the earliest genetic alteration in low-grade gliomas (LGGs), but its role in tumor recurrence is unclear. Mutant IDH1 drives overproduction of the oncometabolite D-2-hydroxyglutarate (2HG) and a CpG island (CGI) hypermethylation phenotype (G-CIMP). To investigate the role of mutant IDH1 at recurrence, we performed a longitudinal analysis of 50 IDH1 mutant LGGs. We discovered six cases with copy number alterations (CNAs) at the IDH1 locus at recurrence. Deletion or amplification of IDH1 was followed by clonal expansion and recurrence at a higher grade. Successful cultures derived from IDH1 mutant, but not IDH1 wild-type, gliomas systematically deleted IDH1 in vitro and in vivo, further suggestive of selection against the heterozygous mutant state as tumors progress. Tumors and cultures with IDH1 CNA had decreased 2HG, maintenance of G-CIMP, and DNA methylation reprogramming outside CGI. Thus, while IDH1 mutation initiates gliomagenesis, in some patients, mutant IDH1 and 2HG are not required for later clonal expansions.

  Study EGAS00001001854

• Study of pediatric hepatocellular carcinoma caused by bile salt export pump deficiency

  Hepatocellular carcinoma (HCC) is almost invariably associated with an underlying inflammatory state, whose direct contribution to the acquisition of critical genomic changes is unclear. We mapped the acquired genomic alterations in human and mouse HCCs induced by defects in hepatocyte biliary transporters, which expose hepatocytes to bile salts and cause the onset of chronic inflammation that develops into cancer. In both human and mouse cancer genomes we found few somatic point mutations with no impairment of cancer genes, but instead massive gene amplification and rearrangements. This genomic landscape differs greatly from that of virus- and alcohol-associated liver cancer. Copy number gains preferentially occurred at late stages of cancer development and frequently targeted the MAPK signaling pathway, and in particular direct regulators of JNK. The pharmacological inhibition of JNK retarded cancer progression in the mouse. Our study demonstrates that intrahepatic cholestasis leading to hepatocyte exposure to bile acids and inflammation promotes cancer through genomic modifications that can be clearly distinguished from those determined by other etiological factors.

  Study EGAS00001000749

• Genetic control of the transcriptomic response of monocytes to bacterial and viral stimuli assessed by RNA-seq in Africans and Europeans

  Humans differ in the outcome that follows exposure to life-threatening pathogens, yet the extent of population differences in immune responses, and their genetic and evolutionary determinants, remain undefined. Here, we characterized, using RNA-sequencing, the transcriptional response of primary monocytes from Africans and Europeans to bacterial and viral stimuli - ligands activating Toll-like receptors pathways (TLR1/2, TLR4 and TLR7/8) and influenza virus - and mapped expression quantitative trait loci (eQTL). We identify multiple cis- and trans-eQTL that contribute to the marked differences in immune responses detected within and between populations, including a TLR1 master regulator that decreases expression of pro-inflammatory genes in Europeans only. We show that regulatory variants have been privileged targets of natural selection, uncovering evolutionarily advantageous mechanisms, such as attenuated inflammation. Finally, we demonstrate that admixture with Neandertals introduced regulatory variants into European genomes, affecting preferentially responses to viral challenges, and identify archaic haplotypes that contributed to population genetic adaptation.

  Study EGAS00001001895

• Primary prostate Hi-C

  Prostate cancer is a heterogeneous disease whose progression is linked to genome instability. Despite large-scale tumour sequencing efforts, the impact of mutations on the genetic architecture in cancer remains ill-defined due to limited integration of genomics data across dimensions. We addressed this limitation by assessing the impact of structural variants on the chromatin states and the three-dimensional organization across benign and malignant primary prostate genomes. We find high concordance in the three-dimensional genome organization between malignant and benign prostate tissues, arguing for constraints to the three-dimensional genome of prostate tumours. Moreover, we identify structural variants as effectors of changes to focal chromatin interactions, guiding cis-regulatory element hijacking that imposes opposing expression changes on genes found at antipodes of a rearrangement. This leads to the repression of tumour suppressor gene expression and up-regulation of oncogenes, such as at the TMPRSS2-ERG and PMEPA1-ZNF156 loci. Collectively, our results argue that cis-regulatory element hijacking by structural variants overshadows large-scale topological changes to alter gene regulation and promote oncogenesis.

  Study EGAS00001005014

• An essential role for MYB in driving oncogenic EVI1 expression in enhancer-rearranged leukemias

  In acute myeloid leukemia (AML) with inv(3)(q21;q26) or t(3;3)(q21;q26), a translocated GATA2 enhancer drives oncogenic expression of EVI1. We generated an EVI1-GFP AML model and applied an unbiased CRISPR/Cas9 enhancer scan to uncover sequence motifs essential for EVI1 transcription. Using this approach, we pinpoint a single regulatory element in the translocated GATA2 enhancer that is critically required for aberrant EVI1 expression while being dispensable for GATA2 expression from its endogenous locus. This element contains a DNA binding motif for the transcription factor MYB that heavily occupies this site specifically at the translocated allele. MYB knockout as well as peptidomimetic blockade of p300-dependent MYB function resulted in downregulation of EVI1 but not of GATA2. Targeting MYB or mutating its DNA-binding motif within the GATA2 enhancer resulted in myeloid differentiation and cell death, suggesting that interference with MYB-driven EVI1 transcription provides a potential entry point for therapy of inv(3)/t(3;3) AMLs.

  Study EGAS00001004839

• The ICGC-TCGA DREAM Somatic Mutation Calling - Tumour Heterogeneity Challenge

  Tumors are composed of many different cell types, ranging from the normal tissue micro-environment, infiltrating immune cells and tumour cells. This group of tumour cells is itself intrinsically highly heterogeneous, driven by the rapid mutation rate of cancer cells to become a mixture of different sub-populations. These different types of cells, called subclones, have different sets of mutations in their DNA. Because some subclones evolve from others, many subclones share mutations. While it is increasingly easy to determine what mutations are present in the tumor, it remains very difficult to determine which subclones have which mutations. The task of assigning mutations to subclones is called subclonal reconstruction.The ICGC-TCGA DREAM Somatic Mutation Calling - Tumour Heterogeneity Challenge (SMC-Het) is an international effort to improve standard methods for subclonal reconstruction: to quantify and genotype each individual cell population present within a tumor. The goal of this challenge is to identify the best subclonal reconstruction algorithms and to identify the conditions that affect their performance.

  Study EGAS00001002092