12444 results for "cancer studies using rna-seq"

in 44.28 milliseconds.

• DNA demethylation is associated with malignant progression of low-grade gliomas

  To elucidate the mechanisms of tumor progression is key to discovering strategies for treating patients with lower-grade glioma. Thus to characterize the changes in the molecular profile during malignant progression, we performed methylation array analysis (122 tumors), whole-exome sequencing (36 tumors and matched normal samples), and RNA sequencing (31 tumors). This cohort included 24 matched pairs of initial lower-grade gliomas and recurrent tumors, most of which showed malignant progression when they recurred. Nearly half of IDH-mutant glioblastomas that had progressed from lower-grade gliomas exhibited characteristic partial DNA demethylation in previously methylated genomic regions of their corresponding initial tumors, which had the glioma CpG island methylator phenotype (G-CIMP). In these glioblastomas, cell cycle-related genes were upregulated, RB and PI3K-AKT pathway genes were frequently altered. Notably, bioinformatics analysis revealed that late-replicating domain was significantly enriched in the demethylated regions that were mostly located in non-regulatory regions, suggesting that the loss of DNA methylation during malignant transformation may involve mainly passive demethylation due to a delay in maintenance of methylation during accelerated cell division. Nonetheless, a limited number of genes including IGF2BP3, which potentially drives cell proliferation, were presumed to be upregulated due to demethylation of their promoter. Thus, cell proliferation was further promoted by passive demethylation in the promoter region of these oncogenic genes. Our data indicated that demethylation of the G-CIMP profile found in a subset of recurrent gliomas reflects accelerated cell divisions accompanied by malignant transformation. Oncogenic genes activated by such epigenetic change represent potential therapeutic targets.

  Study JGAS000146

• Systemic Lupus Erythematosus Serum Stimulation of Human Intestinal Organoids Induces Barrier Leakiness and Changes in Goblet Cell Differentiation

  Human intestinal epithelial cells are the interface between potentially harmful luminal content and basally residing immune cells. Their role is not only nutrient absorption but also the formation of a tight monolayer that constantly secretes mucus creating a multi-layered protective barrier. Alterations in this barrier can lead to increased gut permeability which is frequently seen in individuals with chronic extraintestinal autoimmune diseases, such as Systemic Lupus Erythematosus (SLE). Despite recent advances in identifying alterations in gut microbiota composition in SLE patients, not much attention has been given to the epithelial barrier itself. To date, it remains largely unexplored which role and function intestinal epithelial cells have in SLE pathology. Here, we present a unique near-physiologic in vitro model specifically designed to examine the effects of SLE on the epithelial cells. We utilize human colon organoids that are stimulated with serum obtained from SLE patients. Combining bulk and single-cell RNA transcriptomic analysis with functional assays revealed that SLE serum stimulation induced a unique expression profile marked by a reduction of goblet cell marker expression and mucus composition. Additionally, organoids exhibited imbalanced cellulat composition along with enhanced paracellular permeability,mitochondrial function, and a type I interferon gene signature. Similarly, transcriptomic analysis of SLE human colon biopsies revealed a downregulation of epithelial secretory markers. Our work uncovers a crucial connection between SLE and intestinal homeostasis that might be promoted in vivo through the blood, offering insights into the causal connection of barrier dysfunction and autoimmune diseases.

  Study EGAS50000000012

• Blood DNA Methylation in Post-Acute Sequelae of COVID-19 (PASC): a Prospective Cohort Study

  Background: DNA methylation integrates environmental signals with transcriptional programs. COVID-19 infection induces changes in the host methylome. While post-acute sequelae of COVID-19 (PASC) is a long-term complication of acute illness, its association with DNA methylation is unknown. No universal blood marker of PASC, superseding single organ dysfunctions, has yet been identified. Methods: In this single center prospective cohort study, PASC, post-COVID without PASC, and healthy participants were enrolled to investigate their symptoms association with peripheral blood DNA methylation data generated with state-of-the-art whole genome sequencing (WGS). PASC-induced quality-of-life deterioration was scored with a validated instrument, SF-36. Analyses were conducted to identify potential functional roles of differentially methylated loci, and machine learning algorithms were used to resolve PASC severity. Findings: 103 patients with PASC (22.3% male, 77.7% female), 15 patients with previous COVID-19 infection but no PASC (40.0% male, 60.0% female), and 27 healthy volunteers (48.1% male, 51.9% female) were enrolled. Whole genome methylation sequencing revealed 39 differentially methylated regions (DMRs) specific to PASC, each harboring an average of 15 consecutive positions, that differentiate patients with PASC from the two control groups. Motif analyses of PASC-regulated DMRs identify binding domains for transcription factors regulating circadian rhythm and others. Some DMRs annotated to protein coding genes were associated with changes of RNA expression. Machine learning support vector algorithm and random forest hierarchical clustering reveal 28 unique differentially methylated positions (DMPs) in the genome discriminating patients with better and worse quality of life.

  Study phs003658

• Healthy_ageing_thymus

  Single cell RNA sequencing of immune and non-immune cells from healthy ageing thymus Thymus is a primary lymphoid organ that creates an environment for the T lymphocyte precursors differentiation into the naive T cells, which involves TCR gene rearrangement, negative and positive selection. Despite thymus critical function for the recognition of the pathogens it starts to atrophy very early in life. Thymic Epithelial Space (TES), where thymocyte education occurs, starts to decline rapidly just after birth, while with the onset of puberty thymus is also progressively replaced with adipose tissue. This leads to a reduced naive T cell output,which decreases an organism's ability to recognize pathogens. In our lab, we have already collected and characterized cell type composition and gene regulatory networks of the fetal tand adult human thymus (Park et al, Science 2020). In the current project we plan to expand the number of paediatric and adult samples in the study with the aim to understand how the process of thymic involution happens. We will use single-cell transcriptomics to zoom on changes that occur in immune and non-immune cell types in different phases of thymic involution with the hope to understand which gene expression changes are causal for the thymic involution process and how naïve T cell production can be increased in elderly. 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 EGAS00001004311

• T-cell reconstitution after reduced dose ATLG induction in kidney transplant patients

  We analyzed the T-cell receptor (TCR) repertoires from ten kidney transplant recipients. Five out of the ten kidney transplant recipients received ATLG while the other five recipients received basiliximab as induction therapy. TCR repertoires of CD4+ and CD8+ positive T-cells were assessed prior to transplantation and within the first month after transplantation as well as at three- and 12-months post-transplant. In addition, the pre-formed alloreactive TCR repertoire for each kidney transplant recipient was identified using mixed lymphocyte reaction and donor reactive T-cells were subjected to TCR beta sequencing. This dataset comprises a total of 106 samples. NGS TCR beta libraries of all samples were sequenced on an Illumina NextSeq 500 and raw sequencing data (in the form of fastq files) as well assembled clonotypes and their counts (in the form of clonotype tables) are provided.

  Dataset EGAD00001008478

• Spatially resolved antigen receptor and gene expression data from human tonsil tissue

  The dataset includes spatially-resolved gene expression and antigen receptor data from two Tonsil samples (1 and 2). Tissue sections from the tonsil samples were used for spatial transcriptomics (Visium, 10x genomics). Tonsil 2 tissue sections were analyzed by a new method (Spatial VDJ) to spatially resolve antigen receptor sequences (target capture), which was developed in our publication. Nearby or adjacent tissue sections (from Tonsil2) were also analyzed by a bulk antigen receptor sequencing approach (amplicon sequencing), by a method also newly developed by us in the same publication (Bulk SS3 VDJ). For Visium, the data were anonymized (all SNPs removed) using Bamboozle (Ziegenhain and Sandberg, Nature Communications 2021). The deposited data is in the form of fastq files. All remaining data, metadata, micrographs of the tissue sections (of those used for spatial transcriptomics), and scripts used for the analysis are available at Zenodo (DOI: 10.5281/zenodo.7961605). Final libraries were sequenced on NextSeq2000 (Illumina) or NovaSeq6000 (Illumina) and analyzed with Seurat, Space Ranger, and STutility pipelines.

  Dataset EGAD00001011062

• Oesophageal adenocarcinoma WGS from LUD2015-005 study (NCT02735239, EudraCT 2015-005298-19)

  This dataset contains whole genome sequencing (WGS) generated from the inoperable cohorts of the LUD2015-005 study (NCT02735239, EudraCT 2015-005298-19). WGS data were generated with the aim to assess previously reported (e.g. tumour mutational burden) and novel predictive genomic markers for immunochemotherapy treatment in this setting. Using these data, mutation and copy number profiles were generated for the LUD2015-005 study, which were assessed for correlation with patient outcomes from this trial.

  Dataset EGAD00001009400

• Whole Genome Sequencing of Liver Cancers

  Genomic alterations driving tumorigenesis result from the interaction of environmental exposures and endogeneous cellular processes. With a diversity of risk factors including viral infection, carcinogenic exposures and metabolic diseases, liver cancer is an ideal model to study these interactions. Whole genome sequencing of liver tumors identified 10 mutational signatures showing distinct relationships with environmental exposures, replication and transcription. Transcription-coupled damage was specifically associated with the liver-specific signature 16 and alcohol intake. Flood of indels were identified in very highly expressed hepato-specific genes, likely resulting from replication-transcription collisions. Reconstruction of sub-clonal architecture revealed mutational signature evolution during tumor development exemplified by the vanishing of aflatoxin-B1 signature in African migrants. These findings shed new light on the natural history of liver cancers

  Study EGAS00001002408

• Most HCCs in Taiwan show the mutational signature of aristolochic acid

  Plants in the genus Aristolochia contain the mutagen aristolochic acid (AA) and have been widely used in traditional medicines and for weight loss. AA binds covalently to genomic DNA and induces a highly distinctive mutational signature. While AA involvement in urinary-tract cancers in Taiwan is known, the possible role of AA in hepatocellular carcinomas (HCCs) in Taiwan has not been examined. Here, we whole-exome sequenced 98 unselected HCCs from Taiwan and analyzed the mutational signatures for evidence of AA mutagenesis. Remarkably, more than 78% of HCCs showed strong evidence of AA mutagenesis, often associated with high mutation burdens. Non-synonymous mutations in genes known to be HCC driver genes were detected. Importantly, we elucidated the potential of immunotherapy in this cohort of liver cancer patients.

  Study EGAS00001002301

• High-resolution structural genomics reveals new therapeutic vulnerabilities in glioblastoma

  We investigated the role of 3D genome architecture in instructing functional properties of glioblastoma stem cells (GSCs) by generating the highest-resolution 3D genome maps to-date for this cancer. Integration of DNA contact maps with chromatin and transcriptional profiles identified specific mechanisms of gene regulation, including individual physical interactions between regulatory regions and their target genes. Residing in structurally conserved regions in GSCs was CD276, a gene known to play a role in immuno-modulation. We show that, unexpectedly, CD276 is part of a stemness network in GSCs and can be targeted with an antibody-drug conjugate to curb self-renewal, a key stemness property. Our results demonstrate that integrated structural genomics datasets can be employed to rationally identify therapeutic vulnerabilities in self-renewing cells.

  Study EGAS00001003493