1f96ac42-46c8-48af-843f-7a6951232164 - samples
Ontology highlight
ABSTRACT:
PROVIDER: EGAD00001008999 | EGA |
REPOSITORIES: EGA
Similar Datasets
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: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: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:Aims: Cancer is an important public health problem worldwide. In recent years, methods based on the analysis of plasma cfDNA which is as an emerging technology have been largely explored for noninvasive prenatal testing and cancer liquid biopsy. We inferred both epigenetic and genetic biomarkers of esophageal cancer (ESCA) in cfDNA with adapted SALP-seq. Materials & methods: Next Generation Sequencing libraries of cfDNA samples from ESCA patients and healthy people were constructed by using SALP-seq. We performed bioinformatics analysis on our sequencing data to find cancer-specific biomarkers. Results & conclusion: 54 important regulatory elements of ESCA, 49 epigenetic and 37 genetic ESCA-specific genes were inferred in cfDNA with SALP-seq, which may ultimately contribute to the development of effective diagnostic and therapeutic approaches for ESCA.
2022-08-28 | GSE136541 | GEO
Project description:Cell free DNA (cfDNA) in human plasma carries abundant information on physiological condition, especially in cancer patients such as esophageal cancer. Next-generation sequencing (NGS) as a rapidly developed technology could decode the information effectively. As a key step of NGS, using existing methods to construct cfDNA sequencing libraries is limited by several shortcomings. In this study, we developed a new NGS library construction method for highly degraded DNA, cfDNA as example, based on Single strand Adaptor Library Preparation (SALP). With the high ligation efficiency of single strand adaptor (SSA) which overhangs 3 random bases at 3' end of a double-strand DNA, the new method could construct the sequencing library with high sensitivity without using specific enzymes except T4 DNA ligase and Taq polymerase. With the special designed barcode T adaptor (BTA), multiple libraries constructed from different samples can be amplified in unbiased strategy and facility to compare. Using this method, this study successfully sequenced and compared totally 20 cfDNA samples derived from esophageal cancer patients and healthy people in whole genome scale. This study also compared the chromatin state between cancer patients and healthy people using cfDNA, identified the significant difference between different health condition. Our findings extend the application of cfDNA beyond the analysis with degraded DNA fragments itself, to the transcription regulation level, which also provide an important clue for biopsy of esophageal cancer and other diseases.
2019-04-12 | GSE116345 | GEO
Project description:Construction of Parallel analysis of RNA ends (PARE) libraries was done as described by German et al., 2009. Raw reads consisting of short sequences of 16 to 21 nts after MmeI digestion.
2018-03-01 | GSE110939 | GEO
Project description:The genome-wide analysis of cfDNA fragmentation patterns in DENQCMs and maternal plasma was performed by deep sequencing using Illumina Novaseq to confirm their biological characteristics. We first performed deep whole genome sequencing of the cfDNA extracted from DENQCMs and maternal plasma cfDNA. Then we analyzed the sequencing data and compared various characteristics of cfDNA fragmentation patterns, such as dinucleotide composition, nucleosome protection length, and nucleosome occupancy based on a windowed protection score (WPS), to the submitter-provided processed data from a healthy individual IH01 (GEO accession GSM1833276).
2019-01-05 | GSE124686 | GEO
Project description:Interventions: Group 1: The project aims to:
Statistically compare the fragment length of cell-free DNA in the blood plasma of 80 patients with a confirmed diagnosis of colorectal carcinoma in stages I-IV with the cfDNA fragment lengths of 50 healthy subjects.
For this purpose, residual amounts of blood plasma samples are used, which are collected anyway as part of theroutine examinations.
Cell-free DNA was isolated from the blood plasma and the fragment lengths are measured using qPCR.
The project ends with the publication of the data.
Group 2: Statistically compare the fragment length of cell-free DNA in the blood plasma of 50 healthy subjects with 80 patients with a confirmed diagnosis of colorectal carcinoma in stages I-IV.
The plasma samples from healthy volunteers were purchased (Central Biohub GmbH).
Primary outcome(s): The aim of this study is: 1) to analyze total cfDNA concentration in CRC patients with different histopathological stages (UICC I-IV). 2) to address the question whether the integrity index of cfDNA increases in CRC patients as a result of elevated necrotic degradation processes. Therefore, we intended to quantify short and long fragments of cfDNA via qPCR independent from total cfDNA levels by using equal template concentrations for CRC patients and healthy individuals. This approach may help to understand whether previously described diagnostic markers are either increased, decreased or unaltered in blood plasma of CRC patients compared to healthy individuals.
Study Design: Allocation: ; Masking: ; Control: ; Assignment: ; Study design purpose: basic science
| 2754663 | ecrin-mdr-crc
Project description:Colorectal polyp is known a precursor of colorectal cancer (CRC) that holds an increased risk for progression to CRC. Circulating cell-free DNA(cfDNA) methylation has shown favorable performance in the detection and monitoring the malignant progression in a variety of cancers. Here, we conducted a study to discovery cfDNA methylation markers for the diagnosis of CRC. We first performed a genome-wide analysis using the Infinium HumanMethylationEPIC BeadChip array to identify differentially methylated CpGs (DMCs) between 8 CRC and 8 polyp tissues. Then, we validated DMCs in a larger tissue cohort and four methylation markers (cg04486886, cg06712559, cg13539460 and cg27541454) were selected as the methylation markers in tissue by LASSO and random forest models. A diagnosis prediction model was bulit based on the four markers and the methylaion diagnosis score (md-score) can effectively discriminate patients with CRC from polyp tissues. Finally, a single cfDNA methylation marker, cg27541454, was confirmed hypermethylated in CRC in the plasma validation cohort. Together, our findings suggested that the md-score derived from tissue could robustly detect CRC from polpy patients, and cg27541454 may be a promising candidate non-invasive biomarker for CRC early diagnosis.
2024-01-01 | GSE220160 | GEO
Project description:Current methods for mapping the tissue-of-origin of circulating cell-free DNA (cfDNA) are still insufficient. Here, we have extended a previously developed methylated CpG tandems amplification and sequencing (MCTA-Seq) method for quantitative analysis of tissue-of-origin of plasma cfDNA. By comparing paired plasma cfDNA and white blood cell genomic DNA, we have demonstrated that the liver is the major non-hematopoietic tissue contributing to plasma cfDNA in healthy adults, accounting for approximately 2%. Furthermore, we have detected changes in liver-derived DNA in patients with benign liver diseases and increases in pancreas-derived DNA in acute pancreatitis patients. Interestingly, our results suggest that DNA derived from pathological tissues makes a minor contribution to the increased cfDNA in many clinical cases. Finally, we have identified a tissue-specific hypermethylated cfDNA marker located in the intragenic regions of tissue-specifichighlyexpressed genes. This study represents valuable progress in the field of cfDNA and offers promise for clinical research and medical diagnostics using the described method.
2019-07-01 | GSE118690 | GEO