Genome-wide plasma cell-free DNA methylation profiling in pancreatic cancer patients using MeDIP-seq
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Illumina HiSeq 2000
ORGANISM(S): Homo sapiens
SUBMITTER: Pengxiao Li
PROVIDER: E-MTAB-9678 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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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:DNA methylation is critical for development and is strongly associated with gene regulation. Variation in the DNA methylome between closely related species may reveal unique functional adaptation. We have implemented a novel inter-primate DNA methylation genome-wide analysis between human, chimpanzee and rhesus macaque to identify human species-specific Differentially Methylated Regions (human s-DMRs) in orthologous loci. We analysed the peripheral blood cell DNA methylomes of these primates and identified 22,758 hypomethylated and 15,858 hypermethylated human s-DMRs. These s-DMRs are globally enriched within weak promoter, enhancer and transcribed regions via comparison with ChromHMM segmentation. Human s-DMRs, (both hypo- and hypermethylated) are found to be more prevalent in CpG Island shores than within the islands themselves (?2 P = 1.80 x 10-32). Examining human-specific Transcription Factor Binding Site motif change within CpG islands, we show gain and loss, in hypomethylated and hypermethylated s-DMRs, respectively, of CTCF motifs. Epigenetically the most divergent human-specific locus was the immunological Leukotriene B4 receptor (LTB4R, aka BLT1 receptor), due to collocating hypomethylated s-DMRs within the promoter CpG island and shore, as well as inverse increased gene body methylation. This gene is vital in host immune responses and associated with the pathogenesis of a wide range of human inflammatory diseases. This finding was supported by additional neutrophil-only DNA methylome and lymphoblastoid H3K4me3 chromatin comparative data. Functional investigation of the consequences of these epigenetic differences identified this receptor to have increased expression, and have a higher response to the LTB4 ligand in human versus rhesus macaque peripheral blood mononuclear cells. This result further emphasises the exclusive nature of the human immunological system, its divergent adaptation even from closely related primates, and the power of comparative epigenomics to identify and understand human uniqueness. DNA methylome analysis of pooled Human, Chimpanzee and Macaque
2014-02-01 | E-GEOD-48942 | biostudies-arrayexpress
Project description:Purpose: Generate genome-wide methylation profiles of non-small cell lung carcinomas (NSCLC) and their matching lung tissues for detection of hypermethylated and hypomethylated regions present in the tumors. Methods: MethylCapture followed by next-generation sequencing (Illumina GAIIx) of 7 nsclc tumor samples and paired lung tissues in replicated, plus one cell line, 2 fully artificially methylated and 2 fully artificially unmethylated controls. Normalization of methylation reads based on CpG coupling factor–method. Relative methylation scores (rms) in 500bp non-overlapping windows. 90th percentile of rpm (reads per million) values for all 500bp genome-wide windows, with rpm <1.33 were considered. Distributions of 10bp bins rms values within each 500bp genomic region were compared using both one-sided Student’s t-test and one-sided Wilcoxon rank-sum test. Testing was done separately for hypo- and hypermethylation and p-value threshold of 10-18. Results: MethylCap-seq data revealed strong positive correlation between replicate experiments and between paired tumor/lung samples. 14472 differentially methylated regions (DMR) with non-overlapping 500 bp windows were found. 57 DMRs were present in all NSCLC tumors. 287 were unique for squamous-cell carcinomas and 26 unique for adenocarcinomas. While hypomethylated DMRs did not correlate to any particular functional category of genes, the hypermethylated DMRs were strongly associated with genes encoding transcriptional regulators. Furthermore, subtelomeric regions and satellite repeats were hypomethylated in the NSCLC samples. Conclusion: We provide a resource containing genome-wide DNA methylation maps of NSCLC and their paired lung tissues, and comprehensive lists of known and novel DMRs and associated genes in NSCLC. The DMRs can be in further studies to develop sensitive biological markers for NSCLC, which may enable non-invasive diagnosis and early detection of the disease, and potentially allow histological classification. MethylCap-seq of 7 nsclc tumor samples and paired lung tissues, plus 2 fully methylated and 2 fully unmethylated controls.
2012-10-05 | E-GEOD-41343 | biostudies-arrayexpress
Project description:MethylCap-seq was performed to characterize the genome-wide DNA methylation in CLBL-1 8.0, a doxorubicin-resistant cDLBCL cell line, and CLBL-1 as control, and aimed to investigate underlying mechanisms of doxorubicin resistance in cDLBCL. Strong difference in methylation pattern of both promoter and gene-body regions was detected between CLBL-1 8.0 and CLBL-1. Methylated peaks with fold-change greater than 4 and a P value of less than 0.01 were defined as differentially methylated regions (DMRs); there were a total of 20289 hypermethylated and 38362 hypomethylated DMRs detected. Among these, 1339 hypermethylated and 4861 hypomethylated DMRs were in promoter regions, while 12855 hypermethylated and 18904 hypomethylated DMRs were in gene-body regions. There were 6.6% hypermethylated DMRs located on the promoter regions. A high percentage (63.4%) of hypermethylated DMRs were distributed within the gene body, and 7.8%, 5.1% and 23.8% hypermethylated DMRs were found to be clustered in upstream, downstream, and intergenic regions, respectively.
2020-10-22 | GSE149925 | GEO
Project description:The aim of the present study was to identify novel DNA methylation markers in bladder cancer (BCa) through genome-wide profiling of bladder cancer cell lines and subsequent MSP screening in urine samples. Experimental Design: MBD methylCap/seq was carried out to screen differentially methylated CpG islands using two BCa cell lines (5637 and T24) and two normal bladder mucosa (BM) samples. The top one hundred most hypermethylated targets were screened using Methylation Specific PCR (MSP) in small and big cohort of urine samples from BCa patients and normal controls. The diagnostic performance of the gene panel was further evaluated in different clinical scenarios. Results: In total, 1,627 gene promoter regions hypermethylated in BCa cell line were identified in genomic level methylation profiling. The followed screening procedure in clinical urine sample generated eight genes (VAX1, KCNV1, ECEL1, TMEM26, TAL1, PROX1, SLC6A20, and LMX1A) capable of differentiating BCa from normal control. Subsequent validation in a large sample size enabled the optimisation of 5 methylation targets (VAX1, KCNV1, TAL1, PPOX1 and CFTR) for BCa diagnosis with sensitivity and specificity of 86.32% and 87.13%, respectively. In addition, VAX1 and LMX1A methylation could predict the tumour recurrence. Conclusions: Tumor specific biomarkers of BCa could be established by first performing genome level methylation profiling with cell lines and then screening the potential targets in urine samples. The panel of methylated genes identified was promising for the early non-invasive detection and surveillance of BCa. MBD methylCap/seq was carried out to screen differentially methylated CpG islands using two BCa cell lines (5637 and T24), and two normal bladder tissue mix as control.
2012-04-30 | E-GEOD-33839 | biostudies-arrayexpress
Project description:Aberrant CpG methylation is a universal trait of cancer cell genomes and can result in epigenetic modulation of gene activity; however, at which stages tumour-specific epigenetic patterns arise is unknown. Here, we analyse the methylome of APCM in mouse intestinal adenoma as a model of intestinal cancer initiation, and inventory a map of over 13,000 adenoma-specific recurrent differentially methylated regions (DMRs). We find that multiple genes coding for Polycomb proteins are upregulated in adenoma, and concomitantly, hypermethylated DMRs form preferentially at Polycomb target sites. We establish that DMRs are absent from proliferating intestinal epithelial cells or intestinal stem cells, and thus arise de novo after loss of APC. Importantly, a core set of DMRs is conserved in human colon cancer, defining a class of early epigenetic alterations that are distinct from known sets of epigenetically silenced tumour suppressors. The data presented suggests a sequence of events that leads to an altered methylome of colon cancer cells, and may allow more specific selection of clinical epigenetic biomarkers. Analysis of the methylome and RNA expression in adenoma of Apc-Min/+ mutant mice and of normal intestine in Apc-Min/+ and Apc-+/+ wild type mice.
2013-04-03 | E-GEOD-38983 | biostudies-arrayexpress
Project description:This submission contains the data from https://www.biorxiv.org/content/10.1101/795047v2.full This dataset contains processed data of cell-free reduced representation bisulfite sequencing from 60 pediatric cancer samples, in order to classify them according to histopathological diagnosis. Files are provided in bismark coverage format. Samples were sequenced on a NextSeq 500.
2020-02-27 | E-MTAB-8770 | biostudies-arrayexpress
Project description:The early detection of tissue and organ damage associated with autoimmune diseases (AID) has been identified as key to improve long-term survival, but non-invasive biomarkers are lacking. Elevated cell-free DNA (cfDNA) levels have been observed in AID and inflammatory bowel disease (IBD), prompting interest to use cfDNA as a potential non-invasive diagnostic and prognostic biomarker. Despite these known disease-related changes in concentration, it remains impossible to identify AID and IBD patients through cfDNA analysis alone. By using unsupervised clustering on large sets of shallow whole-genome sequencing (sWGS) cfDNA data, we uncover AID- and IBD-specific genome-wide patterns in plasma cfDNA in both the obstetric and general AID and IBD populations. Supervised learning of the genome-wide patterns allows AID prediction with 50% sensitivity at 95% specificity. Importantly, the method can identify pregnant women with AID during routine non-invasive prenatal screening. Since AID pregnancies have an increased risk of severe complications, early recognition or detection of new onset AID can redirect pregnancy management and limit potential adverse events. This method opens up new avenues for screening, diagnosis and monitoring of AID and IBD.
2022-09-14 | E-MTAB-11607 | biostudies-arrayexpress
Project description:We present genome-scale maps of DNA methylation in early human development and perform comparative analysis to mouse that confirm a conserved global erasure of the paternal genome. We find that while many global features of the early embryo are consistent between the two species, the target sequences in which DNA methylation is maintained are distinct. Repetitive elements show a broader range of class specific behaviors in the human embryo and a larger degree of methylation escape in human sperm. We identify thousands of differentially methylated regions (DMRs) that are likely of maternal origin and found that these gamete contributed DMRs are far more species-specific than expected given the conservation of canonical imprint control regions (ICRs). Finally, we extended our studies to the derivation of new human embryonic stem cell (ESC) lines and found notable divergences in DNA methylation signatures from those found in the human embryo and different mouse ESC derivation conditions. Comparison of DNA methylation patterns in human early development, human ESC derivation and mouse ESC derivation
2014-07-23 | E-GEOD-51239 | biostudies-arrayexpress
Project description:Objective: To define the role of epigenetics, particularly DNA methylation in adaptive vascular growth in hyperlipidemic and type 2 diabetic mouse models of hind limb ischemia Methods: Unilateral hindlimb ischemia was induced by ligating femoral artery proximal to the bifurcation of superficial and deep femoral artery. DNA was isolated from ischemic muscles collected at day 7 after ischemia induction using DNeasy Tissue kit (Qiagen). 5 µg of genomic DNA was sheared into small fragments with a mean size of 150 bp by using a Covaris⢠S2 sonicator System. Quality of the fragmentation was analyzed with Bioanalyzer. Fragmented DNA samples were used for preparation of DNA fragment libraries and sequenced on the SOLiD4 sequencing instrument on one flow cell for 50 bp reads. The sequencing reads were mapped to mus musculus genome build mm9. Data was analyzed by using Bioscope. The samples were normalized with the MEDIPS package in R/B Bioconductor. The analysis of CpG methylation was done primarily in the proximal promoter regions encompassing a region of â1kb upstream of the transcription start site (TSS) and +500 bp downstream of the TSS. Comparisons were performed between hyperlipidemic versus controls and diabetic versus controls to detect differentially methylated regions. R package Limma was used for performing the statistical testing between the groups. Results: When visualizing the whole normalized data the samples did not cluster according to the sample groups. Especially two samples from hyperlipidemic and diabetic ischemic muscles differed clearly from the rest of the samples. To detect the differentially methylated genes, stringent thresholds for p-values and fold change values were chosen to list a reasonable number of genes. Upon filtering, significant differences in the methylation patterns of the sample groups were observed. More importantly, when clustering only the filtered genes, the samples clustered clearly according to the sample groups giving evidence of condition-dependent behavior. Using a threshold of methylation fold change of >1.2 and p value <0.05, we identified 397 and 446 genes to be hypomethylated in hyperlipidemic and diabetic ischemic muscles respectively compared to controls. There were 46 genes commonly shared, but still having a unique pattern of hypomethylation in 371 and 394 genes in hyperlipidemic and diabetic ischemic muscles respectively compared to controls. Similarly, there were 371 and 394 genes hypermethylated in hyperlipidemic and diabetic ischemic respectively compared to controls. Interestingly, we found 264 genes to be commonly hypermethylated, whereas 107 and 130 genes were uniquely hypermethylated in hyperlipidemic and diabetic ischemic muscles respectively. Thus, proximal promoter methylation suggested a shared, yet distinct pattern of DNA methylation in ischemic muscles of hyperlipidemic and type 2 diabetic mice compared to controls. Out of 397 genes that were hypomethylated in hyperlipidemic ischemic muscle, 68 genes were shown to be upregulated in âproinflammatory M1 macrophagesâ as shown by recent studies. Similarly, out of the 371 hypermethylated genes 93 genes were shown to be upregulated in âanti-inflammatory and proangiogenic M2 macrophagesâ as described recently. Out of 446 hypomethylated genes in diabetic ischemic muscle, 65 genes were shown to be upregulated in âproinflammatory M1 macrophagesâ as shown recently. Similarly, out of 394 hypermethylated genes 105 genes were specifically upregulated in âanti-inflammatory and proangiogenic M2 macrophagesâ as shown recently. qRT-PCR analysis suggested an inverse relationship between proximal promoter hypermethylation and mRNA expression in a subset of M2 macrophage specific genes in hyperlipidemic and type 2 diabetic ischemic muscles compared to control ischemic muscles. Conclusions: Our results suggest a role of epigenetics particularly proximal promoter DNA methylation in macrophage polarization and their contribution to angiogenesis and tissue repair in hyperlipidemic and type 2 diabetic mouse models of hind limb ischemia. Epigenetics at the level of DNA methylation may act as a deciding factor in promoting a pro or anti-inflammatory phenotype of macrophages critical in cardiovascular diseases. Ischemic skeletal muscle DNA methylation sequencing of triplicate samples from C57BL/6J (WT) mice, hyperlipidemic mice (LDLR-/-ApoB100/100 , C57BL/6J background) and type 2 diabetic mice (IGF-II/LDLR-/-ApoB100/100 , C57BL/6J background) using SoliD4 sequencing platform
2015-12-21 | E-GEOD-42092 | biostudies-arrayexpress