Quality evaluation of Methyl Binding Domain based kits for enrichment DNA-methylation sequencing
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ABSTRACT: Purpose: to compare different Methyl Binding Domain (MBD) based kits for DNA-methylation sequencing using Reduced Representation Bisulfite Sequencing (RRBS) data for validation, and to determine whether data quality can also be derived from inherent sequence data characteristics MBD-seq using 5 different kits (MethylCap, MethylCollector, MethylCollector Ultra, MethylMiner, MethylMagnet) was applied on 3 commonly used cell lines (DU145, HCT15, PC3), for which also RRBS data were generated.
Project description:Because gastric cancer cells already had genetic and epigenetic alterations which can affect the gastric carcinogenesis, we tried to characterize genetic and epigenetic changes during gastric carcinogenesis. To do this, we performed MBD sequencing and RRBS sequencing. MBD and RRBS sequencing of gastric mucosa, intestinal metaplasia, and gastric cancer cells from one patient were generated by NGS using Illumina GAII.
Project description:DNA methylation and the Polycomb Repression System are epigenetic mechanisms that play important roles in maintaining transcriptional repression. Recent evidence suggests that DNA methylation can attenuate the binding of Polycomb protein components to chromatin and thus plays a role in determining their genomic targeting. However, whether this role of DNA methylation is important in the context of transcriptional regulation is unclear. By genome-wide mapping of the Polycomb Repressive Complex 2 (PRC2)-signature histone mark, H3K27me3, in severely DNA hypomethylated mouse somatic cells, we show that hypomethylation leads to widespread H3K27me3 redistribution, in a manner that reflects the local DNA methylation status in wild-type cells. Unexpectedly, we observe striking loss of H3K27me3 and PRC2 from Polycomb-target gene promoters in DNA hypomethylated cells, including Hox gene clusters. Importantly, we show that many of these genes become ectopically expressed in DNA hypomethylated cells, consistent with loss of Polycomb-mediated repression. An intact DNA methylome is required for appropriate Polycomb-mediated gene repression by constraining PRC2 targeting. These observations identify a previously unappreciated role for DNA methylation in gene regulation and therefore influence our understanding of how this epigenetic mechanism contributes to normal development and disease. comparison of Dnmt1+/+ vs Dnmt1-/- mouse embryonic fibroblasts by Reduced Representation Bisulfite Sequencing
Project description:Reduced representation bisulfite sequencing (RRBS) of hematopoeitic stem/progenitor cells and mature B-cells from wild-type mice and mice transiently expressing Bcl6 under control of the Sca1 promoter. CBAxC57BL/6J mice were engineered to transiently express a Bcl6 cDNA in hematopoeitic stem/progenitor cells under control of the Sca1 promoter and then delete the transgene by cre-mediated recombination upon expression of Cd79a (Sca1-BCL6?). Hematopoeitic stem/progentior cells (HSPC, Sca1+Lin-) from the bone marrow and mature B-cells (B220+) from the peripheral blood were isolated from these mice and wild-type CBAxC57BL/6J mice by fluorescence activated cell sorting. Cells from 6-9 mice were pooled, for a total of 4 experimental conditions. DNA was extracted for each condition and analyzed by reduced representation bisulfite sequencing.
Project description:The de novo DNA methyltransferases Dnmt3a and Dnmt3b are of crucial importance in hematopoietic stem cells, and Dnmt3b has recently been shown to play a role in genic methylation. Forced Dnmt3b expression induced widespread DNA hypermethylation in myc-bcl2 induced leukemias, especially at promoters and gene bodies of stem cell-related genes. MLL-AF9 induced leukemogenesis showed much less pronounced DNA hypermethylation upon Dnmt3b expression. Nonetheless, leukemogenesis was delayed in both models with a shared core set of DNA hypermethylated regions and suppression of stem cell-related genes. Our findings indicate a critical role for Dnmt3b-mediated DNA methylation in leukemia development and maintenance of LSC function. To investigate how Dnmt3b-mediated DNA methylation affects leukemogenesis, we analyzed leukemia development under conditions of high and physiological methylation levels in a tetracycline-inducible knockin mouse model. High expression of Dnmt3b slowed leukemia development in serial transplantations and impaired leukemia stem cell (LSC) function.
Project description:Using paired tumor and non-tumor lung tissues from 47 individuals we identified common changes in DNA methylation associated with the development of non-small cell lung cancer. Pathologically normal lung tissue taken at the time of cancer resection was matched to tumorous lung tissue and together were probed for methylation status using Illumina GoldenGate arrays. For each matched pair the change in methylation at each CpG was calculated (the odds ratio), and these ratios were averaged across individuals and ranked by magnitude to identify the CpGM-bM-^@M-^Ys with the greatest change in methylation associated with tumor development. Using paired tumor and non-tumor lung tissues from 47 individuals we identified common changes in DNA methylation associated with the development of non-small cell lung cancer. Pathologically normal lung tissue taken at the time of cancer resection was matched to tumorous lung tissue and together were probed for methylation status using Illumina GoldenGate arrays. For each matched pair the change in methylation at each CpG was calculated (the odds ratio), and these ratios were averaged across individuals and ranked by magnitude to identify the CpGM-bM-^@M-^Ys with the greatest change in methylation associated with tumor development.
Project description:We compared the methylated and non-methylated regions in the genome of ex vivo-isolated naive CD4+ T cells, Th1 cells, Th17 cells and regulatory T cells by methyl-CpG binding domain protein sequencing (MBD-seq). Naive T cells and Th1 cells share more methylated regions than naive T cells and Th17 cells or Th1 and Th17 cells. However, analysis of the non-methylated regions revealed the highest similarity between Th1 and Th17 cells. Another aim was the analysis of the Th17 lineage on the basis of the methylome. We searched for regions absent in the methylome of Th17 but present in naive T cells, Th1 cells and regulatory T cells. Here, we identified differential methylation in the loci of Il17a, Chn2, Dpp4 and Dclk1. CD4+ T effector cells were prepared ex vivo, stimulated with PMA/Ionomycin, subjected to a comercially available cytokine secretion kit (IL-17A and IFNg), stained by adding fluorescence-labeled antibodies against CD3, CD4 and CD45RB and sorted by flow cytometry. We sorted naive CD4+ T cells (CD3+CD4+CD45RB_high), Th1 cells (CD3+CD4+CD45RB_low_IFNg+IL17A-), Th17 cells (CD3+CD4+CD45RB_low_IFNg-IL17A+) and regulatory T cells (CD3+CD4+CD25++).
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
Project description:We report a method for specific capture of an arbitrary subset of genomic targets for single molecule bisulfite sequencing, and for digital quantitation of DNA methylation at a single nucleotide resolution. We used targeted bisulfite sequencing to characterize the changes of DNA methylation during the de-differentiation of human fibroblasts into hybrid stem cells, and into induced pluripotent stem cells. We compared the methylation level of approximately 66,000 CpG sites within 2020 CpG islands on chromosome 12, chromosome 20, and 34 selected regions. A total of 288 differentially methylated regions were identified between fibroblasts and pluripotent cells. Methylation cluster analysis revealed distinct methylation patterns between fibroblasts and pluripotent cells. Furthermore iPS cells are globally more methylated than human embryonic stem cells, which could be due to the reprogramming process. This targeted bisulfite sequencing method is particularly useful for efficient and large-scale analysis of DNA methylation in organisms with large genomes. Experiment Overall Design: Comparison of DNA methylation on 2020 CpG islands and 34 other selected regions among eleven human ES, iPS and fibroblast lines.
Project description:We report the application of DNA sequencing technology for high-throughput sequencing of mix bis-PCR products totally 38 based on bisulfate treated DNA from human, chimpanzee, gibbon, macaque and crab eating macaque profrontal cortex tissues. Mix bisulfate PCR products from 1 tissues, 23 individula humans, 2 individual chimpanzees, 1 individual gibbons, 7 individual rhesus macaques and 5 crab eating macaques were sequenced by using MiSeq
Project description:Using primary breast tumors from 162 women from the Kaiser Division of Research Pathways Study and the Illumina GoldenGate methylation bead-array platform, we measured CpG loci associated with cancer-related genes 162 tumor specimens from the initial diagnostic biopsy were obtained from the KPNC tumor biorepository for methylation analysis. All tumor specimens were from patients who did not receive neoadjuvant chemotherapy. The Pathways Study is a prospective cohort study of breast cancer survival actively recruiting women diagnosed with invasive breast cancer from the Kaiser Permanente Northern California (KPNC) patient population since January 2006. Further study details are provided in Kwan ML et al. Cancer Causes Control 2008. Written informed consent is obtained from all participants before they are enrolled in the study. The study was approved by the IRB of KPNC and all collaborating sites.