Ontology highlight
ABSTRACT:
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| ERR260327.fastq.gz | Fastqsanger.gz | |||
| ERR260328.fastq.gz | Fastqsanger.gz | |||
| ERR260329.fastq.gz | Fastqsanger.gz | |||
| ERR260330.fastq.gz | Fastqsanger.gz | |||
| ERR260331.fastq.gz | Fastqsanger.gz |
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Project description:Nucleosomes are the basic unit of packaging of eukaryotic chromatin, and nucleosome positioning can differ substantially between cell types. Here, we sequence 14.5 billion plasma-borne cell-free DNA (cfDNA) fragments (700-fold coverage) to generate genome-wide maps of in vivo nucleosome occupancy. We identify 13 million local maxima of nucleosome protection, spanning 2.53 gigabases (Gb) of the human genome, whose positions and spacings correlate with nuclear architecture, gene structure and gene expression. We further show that short cfDNA fragments - poorly recovered by standard protocols - directly footprint the in vivo occupancy of DNA-bound transcription factors such as CTCF. The sequence composition of cfDNA has previously been used to noninvasively monitor cancer, pregnancy and organ transplantation, but a key limitation of this paradigm is its dependence on genotypic differences to distinguish between contributing tissues. We show that nucleosome spacing in gene bodies and cis-regulatory elements, inferred from cfDNA in healthy individuals, correlates most strongly with transcriptional and epigenetic features of lymphoid and myeloid cells, consistent with hematopoietic cell death as the normal source of cfDNA. We build on this observation to show how in vivo nucleosome footprints can be used to infer the cell types that contribute to circulating cfDNA in pathological states such as cancer. Because it does not rely on genotypic differences, this strategy may enable the noninvasive cfDNA-based monitoring of a much broader set of clinical conditions than is currently possible. Sequencing of cfDNA libraries from healthy individuals, pooled healthy individuals and individuals with disease for the identification of nucleosomes and protection from other DNA binding proteins.
2015-11-04 | E-GEOD-71378 | biostudies-arrayexpress
Project description:We aimed to clarify the cell-free DNA (cfDNA) physiological role. We exposed THP1 cells to plasma from healthy individuals with and without cfDNA and compared their transcriptomes and proteomes.
2020-12-01 | E-MTAB-8574 | biostudies-arrayexpress
Project description:The epigenome of plasma cell-free DNA (cfDNA) has demonstrated promise as both a prognostic and predictive cancer biomarker in liquid biopsies. Currently, it remains unknown whether and why cfDNA 5-hydroxymethylcytosine (5hmC) can identify disease state for non-small cell lung cancer (NSCLC). We profiled 5-hydroxymethylomes using the plasma cfDNA of 302 EGFR-mutant NSCLC patients with different disease states. We found NSCLCs were epigenetically heterogeneous among individuals, especially for cfDNA 5hmC on gene EGFR. The diversity of age, sex, race, smoking status, EGFR-mutation of patients increased the epigenetic heterogeneity of NSCLC, however, only smoking status shaped disease state-associated cfDNA 5hmC. More importantly, disease state-dependent and patients’ characteristics-independent cfDNA 5hmC can be linked to lung function and regulatory elements in human lung cells. Interestingly, although 5-hydroxymethylome heterogeneity of plasma cfDNA among NSCLC patients were detected substantially, cfDNA-5hmC-based machine learning model can accurately predict different disease state in NSCLC.
2025-01-29 | GSE231296 | GEO
Project description:We explored the differential methylation patterns found in cfDNA between healthy controls (individuals with no colorectal findings, NCF) and patients with advanced neoplasia (advanced adenomas and colorectal cancer, AA andCRC) using pooled samples, to determine if pooled serum cfDNA samples can be used to search for non-invasive methylation biomarkers, as an affordable and efficient alternative to tissue biopsy. cfDNA was extracted from serum samples and methylation measurements were assessed with the Infinium MethylationEPIC BeadChip. Data was mainly preprocessed and analyzed with R/Bioconductor packages.
2018-04-17 | GSE110185 | GEO
Project description:We performed all stimulatory experiments using THP1 cell line as a representative of primary human monocytes to show fundamental role of the cfDNA in healthy organisms. The experiments were conducted in duplicates using plasma containing cfDNA (NP) and the reference one with cfDNA removed by DNase (TP) to recognize unequivocally the effect of plasma cfDNA on transcriptome and proteome of monocytes. We used native human plasma samples obtained from healthy volunteers with no animal serum addition to cultivation medium in order to avoid the presence of uncharacterized animal cfDNA in the experiments.
2021-05-18 | PXD017285 | Pride
Project description:As a non-invasive blood testing, the detection of cell-free DNA (cfDNA) methylation in plasma is raising increasing interest due to its diagnostic and biology applications. Although extensively used in cfDNA methylation analysis, bisulfite sequencing is less cost-effective. Through enriching methylated cfDNA fragments with MeDIP followed by deep sequencing, we aimed to characterize cfDNA methylome in cancer patients. In this study, we investigated the cfDNA methylation patterns in lung cancer patients by MeDIP-seq. MEDIPS package was used for the identification of differentially methylated regions (DMRs) between patients and normal ones. Overall, we identified 330 differentially methylated regions (DMRs) in gene promoter regions, 33 hypermethylation and 297 hypomethylation respectively, by comparing lung cancer patients and healthy individuals as controls. The 33 hypermethylation regions represent 32 genes. Some of the genes had been previously reported to be associated with lung cancers, such as GAS7, AQP10, HLF, CHRNA9 and HOPX. Taken together, our study provided an alternative method of cfDNA methylation analysis in lung cancer patients with potential clinical applications.
2019-03-31 | E-MTAB-7163 | biostudies-arrayexpress
Project description:We explored the differential methylation patterns found in cfDNA between no neoplasia (NN; individuals with no colorectal findings, benign pathologies and non-advanced adenomas) and patients with advanced neoplasia (AN; advanced adenomas and colorectal cancer) using pooled samples, for the discovery of non-invasive methylation biomarkers for CRC screening. cfDNA was extracted from serum samples and methylation measurements were assessed with the Infinium MethylationEPIC BeadChip. Data was mainly preprocessed and analyzed with R/Bioconductor packages.
2023-10-01 | GSE186381 | GEO
Project description:We performed shallow whole genome sequencing (WGS) on circulating free (cf)DNA extracted from plasma or cerebrospinal fluid (CSF), and shallow WGS on the tissue DNA extracted from the biopsy in order to evaluate the correlation between the two biomaterials. After library construction and sequencing (Hiseq3000 or Ion Proton), copy number variations were called with WisecondorX.
2021-11-17 | E-MTAB-10548 | biostudies-arrayexpress
Project description:Circulating nucleic acids are present in plasma and are derived from a range of cell types, mainly cells of hematopoietic origin, enabling their use as biomarkers for diseases involving these cell types. Using cell type-specific methylation markers, we determined that megakaryocytes are major contributors to cfDNA (~26%), while erythroblasts contribute 1-4% of cfDNA in healthy individuals. Additionally, we identified megakaryocyte-derived DNA within platelets, providing non-invasive access to the megakaryocyte genome and epigenome. Analysis of cfDNA in women who have received male platelet transfusions indicates that megakaryocyte-derived cfDNA does not originate from platelets but is rather released directly from megakaryocytes. The concentration of megakaryocyte-derived cfDNA is elevated in individuals with pathologies involving increased platelet production (Essential Thrombocythemia, Idiopathic Thrombocytopenic Purpura) and decreased by bone marrow suppression (due to chemotherapy), while erythrocyte progenitor cfDNA is elevated in patients with Thalassemia. Megakaryocyte- and erythroblast-specific DNA methylation patterns may serve as novel biomarkers for pathologies involving increased or decreased thrombopoiesis and erythropoiesis.
2022-10-12 | GSE206818 | GEO
Project description:Cell-free DNA (cfDNA) contains a composite map of the epigenomes of its cells-of-origin. Tissue-specific TF binding inferred from cfDNA could enable us to track disease states in humans in a non-invasive manner. Here, we present a method to identify the subset of genome-wide transcription factor binding sites that are protected in plasma. We map binding at tissue-specific sites of constitutive factor CTCF and tissue-specific factors PU.1, LYL1, ER, and FOXA1 in plasma cfDNA. Our method also captures the chromatin structure around the factor-bound sites in their cells-of-origin. We define pure tumor TF signatures in an in vivo model by applying our method to estrogen receptor-positive (ER+) breast cancer xenografts. The tumor-specific cfDNA protections of ER-α and FOXA1 reflect TF-specific accessibility across human breast tumors, demonstrating our ability to capture tumor TF binding in plasma. By modeling cfDNA from cancer donors as a mixture of healthy plasma and pure tumor signatures, we can identify tumor TF binding in humans. Thus, our method enables non-invasive mapping of the regulatory phenotype of cancer in humans.
2021-05-24 | GSE171434 | GEO