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.
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.
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).
Project description:5-Hydroxymethylcytosine (5hmC) is an important mammalian DNA epigenetic modification that has been linked to gene regulation and cancer pathogenesis. Here we explored the diagnostic potential of 5hmC in cell-free DNA (cfDNA), the circulating DNA found in human plasma which represents a noninvasive window into the health status of the body. We showed that the genome-wide 5hmC distribution in cfDNA can be reliably sequenced by chemical labeling-based 5hmC enrichment. We sequenced cell-free 5hmC from 49 patients of seven different cancer types and found distinct features that can be used for monitoring disease status and progression. Specifically, we discovered that lung cancer leads to a stage-dependent hypohydroxymethlation in cfDNA, whereas hepatocellular carcinoma (HCC) and pancreatic cancer lead to disease-specific changes in the cell-free hydroxymethylome. Our results demonstrate that cell-free 5hmC can be used not only to track the stage of cancer but also to identify tissue of origin in some solid tumors.
Project description:Heterogeneity in DNA methylation status may exist between primary tumors and cfDNA. We compared the genome-wide DNA methylation status between FNA sample of pancreatic tumor and cfDNA samples from the same patients. MBD-sequencing (seq) was performed in paired samples of FNA and cfDNA from two patients. The majority of DNA methylation peaks overlapped in FNA and cfDNA samples (82.6% and 82.9% in patients #1 and #73, respectively). DNA methylation levels of each gene in FNA and cfDNA samples were highly correlated with each other (r=0.98 and 0.97 in samples 1 and 73, respectively)
Project description:We provide the first in vivo evidence of global and local chromatin changes in human aging by analyzing cfDNA from the blood of individuals of different age groups. Our results show that nucleosome signals inferred from cfDNA are consistent with the redistribution of heterochromatin observed in cellular senescence and aging in other model systems. It also revealed age and deteriorating health status correlate with a low-level enrichment of signals from cells in the thyroid gland. In addition, we detected an overall nucleosome loss at several genomic locations, such as transcription start and termination sites, 5’UTR of L1HS retrotransposons and dimeric AluY elements with age.
