B lymphocyte activation induces DNA methylation reprogramming and establishes a common epigenetic signature in memory B and plasma cell compartments
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Deepak Mav
PROVIDER: E-GEOD-24919 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:DNA methylation profiling of human B cell populations representing a developmental series before and after immune activation. The B cells are derived from inflamed tonsils. The B cells were already activated in vivo in patients, therefore there was no need to stimulate the B cells after isolation. Gene expression profiling was also performed from the same samples. Four B cell subsets: Naïve, germinal center B cells (GC), memory B cells, and plasma cells (PC) were purified by FACS ex vivo from tonsils of 8 human subjects. Methylated CpG island Recovery assay (MIRA) was utilized to enrich for methylated DNA fragments from each sample for microarray analysis. *** This Series reports DNA methylation profiling data. ***
2013-08-13 | E-GEOD-24918 | biostudies-arrayexpress
Project description:Elevated DNA methylation in the first intronic region of the BCL6 locus in B cell lymphomas enforces transcription of the BCL6 gene Promoter tiling arrays were used to investigate the distribution of DNA methylation near the promoter region of BCL6 locus Comparison of DNA methylation at promoter regions of lymphoma (Raji) and myeloma (H929) cell lines by methylated CpG island recovery assay (MIRA-chip)
2010-08-20 | E-GEOD-22884 | biostudies-arrayexpress
Project description:A large body of literature suggests that local features of chromatin are crucial in determining functional properties of underlying DNA. The extent to which DNA sequence plays an active role in the establishment and maintenance of patterns of histone and DNA modification at promoters in cells and tissues in an adult animal remains poorly understood. Likewise, whether passage through development is required for refinement of transcriptional states and chromatin marks characteristic of fully differentiated adult cells remains unclear. Here we undertook analysis of gene expression along with the genomic distribution of DNA methylation and a set of histone marks in primary tissues derived from different primordial germ layers in adult mice. We find that promoter CpG content correlated strongly with specific repressive mechanisms. Likewise, RNA polymerase II occupancy and active histone marks were omnipresent on CpG rich promoters regardless of transcriptional output and of cell type. However, these same chromatin features cleanly demarcate transcriptional activity on promoters with low CpG content. While these observations imply an instructive role for DNA sequence in establishment and maintenance of epigenetic states, experimental evidence presented here also suggests an additional role for development in refining these features at individual promoters. DNA methylation and a set of histone marks (H3K4me3, H3K9me2 and H3K27me3) were examined in B cells and liver using Nimblegen mouse promoter arrays.
2014-08-31 | E-GEOD-41447 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2014-08-31 | E-GEOD-41450 | biostudies-arrayexpress
Project description:Maintenance of chromatin structure is essential to eukaryotic life; dysregulation is known to be causal for aberrant development and disease. The Mi-2/nucleosome remodeling and histone deacetylase (NuRD) complex is a multiprotein machine proposed to regulate chromatin structure by nucleosome remodeling and histone deacetylation activities. We identified the localization of MBD3, a component of Mi-2/NuRD complex, in two breast cancer cell lines (MCF7 and MDA-MB-231) using ChIP-Seq. MBD3 showed cell-type specific localization with overlap across cell lines being less than 50%. MBD3 localized across gene bodies, peaking around the transcription start site (TSS). Contrary to existing models, MBD3 preferentially associated with CpG rich promoters marked by H3K4me3. These data suggest that MBD3, and by extension the Mi-2/NuRD complex, may have roles in fine tuning expression for active genes. These data represent an important first step in defining regulatory mechanisms by which Mi-2/NuRD complex controls chromatin structure and gene expression. DamID experiment was performed in human breast cancer cell lines (MCF-7 and MDA-MB-231) in triplicate. Samples were hybridized to NimbleGen Human Whole-Genome Tiling Arrays (0701_HG18_TILE_05_HX1 and 100718_HG18_TILE_05_HX1). MBD3-Dam material was hybridized over Dam-only control.
2013-10-31 | E-GEOD-44774 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2013-10-31 | E-GEOD-44776 | biostudies-arrayexpress
Project description:Maintenance of chromatin structure is essential to eukaryotic life; dysregulation is known to be causal for aberrant development and disease. The Mi-2/nucleosome remodeling and histone deacetylase (NuRD) complex is a multiprotein machine proposed to regulate chromatin structure by nucleosome remodeling and histone deacetylation activities. We identified the localization of MBD3, a component of Mi-2/NuRD complex, in two breast cancer cell lines (MCF7 and MDA-MB-231) using ChIP-Seq. MBD3 showed cell-type specific localization with overlap across cell lines being less than 50%. MBD3 localized across gene bodies, peaking around the transcription start site (TSS). Contrary to existing models, MBD3 preferentially associated with CpG rich promoters marked by H3K4me3. These data suggest that MBD3, and by extension the Mi-2/NuRD complex, may have roles in fine tuning expression for active genes. These data represent an important first step in defining regulatory mechanisms by which Mi-2/NuRD complex controls chromatin structure and gene expression. DamID experiment was performed in human breast cancer cell lines (MCF-7 and MDA-MB-231) in duplicate. Samples were hybridized to Nimblegen 2.1M Deluxe promoter array. MBD3-Dam material was hybridized over Dam-only control.
2013-10-31 | E-GEOD-44773 | biostudies-arrayexpress
Project description:We developed a novel approach to isolate tumor cells with high purity from blood via immunomagnetic enrichment followed by fluorescence activated cell sorting (IE/FACS) and examined copy number alterations in these cells. Magnetic beads coated with EpCAM mAb were added to blood to enrich for tumor cells. Enriched samples were then subjected to FACS analysis using differentially labeled mAbs to distinguish tumor cells (EpCAM+) from leukocytes (CD45+) during sorting. DNA from isolated tumor cells was subjected to whole genome amplification (WGA) and copy number analysis via array comparative genomic hybridization (CGH). The assay was evaluated using BT474 and MCF7 breast cancer cell lines and in CTCs from 5 metastatic breast cancer (MBC) patients with matched archival primary tumors and later extended to an additional 97 MBC patients. Evaluation of the assay on isolated breast cancer cell lines spiked into blood correctly identified the known genomic alterations with high reproducibility. In clinical studies, comparison of CTCs with matched archival primary tumors confirmed shared lineage with notable divergence. In addition, serial testing of CTCs confirmed reproducibility, and indicated genomic change over time. Analysis of genomic profiles of CTCs from 102 MBC patients revealed common copy number alterations including gains in 1q and 8q and losses in 8p and 11q. Comparison with a published CGH dataset of primary breast tumors revealed similar frequencies of recurrent genomic copy number aberrations.
2012-12-31 | E-GEOD-27511 | biostudies-arrayexpress
Project description:Somatic mosaicism for DNA copy number alterations (SMC-CNA) is defined as gain or loss of chromosomal segments in mitotic cells within a single organism. As cells harboring SMC-CNA have the potential to undergo clonal expansion, SMC-CNA may be present in a substantial portion of cells in differentiated human tissues and may contribute to the predisposition of these cells to genetic disease including cancer. We characterized gross genomic alterations (>500 kbp) in uninvolved glandular tissue from 59 breast cancer patients and matched samples of primary tumors and lymph node metastases. Array based comparative genomic hybridization experiments showed 10% (6/59) of patients harbored 1 - 359 large SMC-CNA (mean: 1328 kbp; median: 961 kbp) in uninvolved glandular tissue. SMC-CNA were partially recurrent in tumors, albeit with considerable contribution of stochastic SMC-can, indicating genomic destabilization. Therefore, we hypothesized that the observed genomic destabilization is predetermined by mutations in genes related to maintenance of genomic integrity. Targeted resequencing of 301 known predisposition and somatic driver loci revealed mutations in the following genes: BRCA1 (p.Gln1756Profs*74, p.Arg504Cys), BRCA2 (p.Asn3124Ile), NCOR1 (p.Pro1570Glnfs*45), PALB2 (p.Ser500Pro) and TP53 (p.Arg306*). We demonstrated that gross SMC-CNA may be present in a substantial portion of glandular tissue cells, which are distant from that of the tumor cells, and may co-occur with point mutations in crucial cancer predisposing or somatic driver genes. Taken together, this highlights temporal and spatial neoplastic potential of uninvolved glandular tissue from breast cancer patients. Characterization of gross genomic alterations (>500 kbp) in uninvolved glandular tissue from 59 breast cancer patients and in the matched samples of primary tumors and lymph node metastases. Corresponding peripheral blood lekocyte DNA, a pool of female DNA (Promega), or uninvolved glandular tissue DNA was used as reference. No biological replicates are included.
2015-07-30 | E-GEOD-63623 | biostudies-arrayexpress
Project description:We purified tumor cells in the CSF (M-bM-^@M-^\CSFTCM-bM-^@M-^]) from 15 metastatic breast cancer patients diagnosed with leptomeningeal disease using a two-step method involving immunomagnetic enrichment and fluorescence-activated cell sorting (IE/FACS). Magnetic beads coated with mAb to the epithelial cell adhesion marker (EPCAM) were used to enrich for tumor cells and were further purified by FACS analysis. For DNA profiling, isolated CSFTC were subjected to molecular characterization through genome-wide copy number analyses. Genomic analyses were then compared with those performed on the corresponding archival primary tumors. For RNA profiling, isolated CSFTC were then subjected to molecular characterization through gene expression profiling via QPCR analysis of 64 cancer-related genes CGH: 17 CSFTC samples from 13 patients were successfully profiled ,1 patient had 5 timepoints, 6 of 13 patients had matched to copy number data archival tumors RNA: 18 samples from 5 patients had successful gene expression data of the 64 genes measured in triplicates. For non-tumor controls, 9 of the samples had matching gene expression data from sorted leuckocytes (+CD45 cells) obtained from the same draw.
2014-01-09 | E-GEOD-46068 | biostudies-arrayexpress