Project description:Epigenomics is developing a colon cancer screening assay based on differential methylation of specific CpG sites for the detection of early stage disease. A genome-wide methylation analysis and oligonucleotide array study using DNA from various stages of colon cancer and normal tissue have been completed to obtain candidate CpG markers. Based on results obtained in the above studies, Epigenomics has moved to the final stages of feasibility with a specific, highly sensitive real-time marker assay that is able to detect colon cancer DNA in blood plasma.
Project description:This SuperSeries is composed of the following subset Series: GSE34655: Genome-wide profiling of DNA methylation in two Arabidopsis ecotypes and their reciprocal hybrids - mRNA-seq GSE34656: Genome-wide profiling of DNA methylation in two Arabidopsis ecotypes and their reciprocal hybrids - small RNA-seq GSE34657: Genome-wide profiling of DNA methylation in two Arabidopsis ecotypes and their reciprocal hybrids - Bisulfite-seq Refer to individual Series
Project description:DNA methylation is an essential epigenetic mark that is required for normal development. Knockout of the DNA methyltransferase enzymes in the mouse hematopoietic compartment reveals that methylation is critical for hematopoietic differentiation. To better understand the role of DNA methylation in hematopoiesis, we characterized genome-wide DNA methylation in primary mouse hematopoietic stem cells (HSC), common myeloid progenitors (CMP), and erythroblasts (ERY). Methyl Binding Domain protein 2 (MBD) enrichment of DNA followed by massively-parallel sequencing (MBD-Seq) was used to map genome-wide DNA methylation. Globally, DNA methylation was most abundant in HSC, with a 40% reduction in CMP, and 67% reduction in ERY. Only 3% of peaks arise during differentiation demonstrating a genome-wide decline in DNA methylation during erythroid development. Analysis of genomic features revealed that 98% of promoter CpG islands are hypomethylated, while 20-25% of non-promoter CpG islands are methylated. Proximal promoter sequences of expressed genes are hypomethylated in all cell types, while gene body methylation positively correlates with gene expression in HSC and CMP. Elevated genome-wide DNA methylation in HSC and the positive association between methylation and gene expression demonstrates that DNA methylation is a mark of cellular plasticity in HSC. Utilizing de novo motif discovery we identified overrepresented transcription factor consensus binding motifs in methylated sequences. Motifs for several ETS transcription factors, including GABPalpha and ELF1 are overrepresented in methylated regions. Our genome-wide survey demonstrates that DNA methylation is markedly altered during myeloid differentiation and identifies critical regions of the genome and transcription factor programs that contribute to hematopoiesis. Examination of changes in methylation profiles during hematopoietic stem cell differentiation
Project description:Histone modification H3K9me2 is associated heterochromatin and gene silencing, but the relationship between DNA methylation and H9K9me2 haven’t been checked in a genome-wide scale. This dataset was generated to compare with genome-wide DNA methylation data.
Project description:Naive pluripotent epiblast cells of the preimplantation murine embryo and their in vitro counterpart, embryonic stem (ES) cells, have the capacity to give rise to all cells of the adult. Such developmental plasticity is associated with global genome hypomethylation. It is unclear whether genome methylation is dynamically regulated only via differential expression of DNA methyltransferases (DNMTs) and Ten-eleven Translocation (TET) enzymes, which oxidase methylated DNA. Here we show that LIF/Stat3 signalling induces genomic hypomethylation via metabolic reconfiguration. In Stat3-/- ES cells we observed decreased alpha-ketoglutarate (ɑKG) production from reductive Glutamine metabolism, leading to decreased TET activity, increased Dnmt3a/b expression and to a global increase in DNA methylation. Notably, genome methylation is dynamically controlled by simply modulating αKG availability, mitochondrial activity or Stat3 activation in mitochondria, indicating effective crosstalk between metabolism and the epigenome. Stat3-/- ES cells also show increased methylation at Imprinting Control Regions accompanied with differential expression of >50% of imprinted genes. Single-cell transcriptome analysis of Stat3-/- embryos confirmed dysregulated expression of Dnmt3a/b, Tet2, and imprinted genes in vivo. Our results reveal that the LIF/Stat3 signal bridges the metabolic and epigenetic profiles of naive pluripotent cells, ultimately controlling genome methylation and imprinted gene expression. Several imprinted genes regulate cell proliferation and are often misregulated in tumors. Moreover, a wide range of cancers display Stat3-overactivation, raising the possibility that the molecular module we described here is exploited under pathological conditions.
Project description:This SuperSeries is composed of the following subset Series: GSE33226: Genome wide DNA methylation analysis of leukemia and reprogrammed leukemia cells (gene expression) GSE33230: Genome wide DNA methylation analysis of leukemia and reprogrammed leukemia cells (sequencing) Refer to individual Series
Project description:Estrogen receptor beta (ERβ) is a ligand inducible transcription factor regulating gene expression in response to the female sex hormone estrogen. Previously, we found that ERβ deficiency results in changes in DNA methylation patterns at two gene promoters, implicating an involvement of ERβ in DNA methylation. In this study, we set out to explore this involvement on a genome-wide level, and to investigate the underlying mechanisms of this function. Using reduced representation bisulfite sequencing (RRBS), we compared genome-wide DNA methylation in mouse embryonic fibroblasts (MEFs) derived from wildtype (wt) and ERβ knock-out (βerko) mice, and identified around 8000 differentially methylated positions (DMPs). This suggests that ERβ is involved in regulating DNA methylation at specific sites in the genome. Genome-wide DNA methylation was analysed in MEFs derived from wildtype and ERbeta null mice by educed representation bisulfite sequencing (RRBS) on an Illumina Genome Analyser IIx platform.
Project description:We analyzed the genome-wide DNA methylation in Zscan4 overexpressing ES cells. Zscan4 overexpression induced slight DNA demethylation in telomere and major satellite regions. Subsequent genome-wide analysis of non-repeated regions revealed the significant reduction of DNA methylation at Zscan4-dependent hyperacetylation sites. This result indicates that Zscan4 is not only a marker of the Zscan4+ state of ES cells, but also indispensable for the dramatic epigenetic modifications occurring in the Zscan4+ state. DNA methylation in Zscan4 overexresssing ES cells
Project description:Genome-wide DNA demethylation is a unique feature of mammalian development and naïve pluripotent stem cells. So far, it was unclear how mammals specifically achieve global DNA hypomethylation, given the high conservation of the DNA (de-)methylation machinery among vertebrates. We found that DNA demethylation requires TET activity but mostly occurs at sites where TET proteins are not bound suggesting a rather indirect mechanism. Among the few specific genes bound and activated by TET proteins was the naïve pluripotency and germline marker Dppa3 (Pgc7, Stella), which undergoes TDG dependent demethylation. The requirement of TET proteins for genome-wide DNA demethylation could be bypassed by ectopic expression of Dppa3. We show that DPPA3 binds and displaces UHRF1 from chromatin and thereby prevents the recruitment and activation of the maintenance DNA methyltransferase DNMT1. We demonstrate that DPPA3 alone can drive global DNA demethylation when transferred to amphibians (Xenopus) and fish (medaka), both species that naturally do not have a Dppa3 gene and exhibit no post-fertilization DNA demethylation. Our results show that TET proteins are responsible for active and - indirectly also for - passive DNA demethylation; while TET proteins initiate local and gene-specific demethylation in vertebrates, the recent emergence of DPPA3 introduced a unique means of genome-wide passive demethylation in mammals and contributed to the evolution of epigenetic regulation during early mammalian development.