ChIP-seq for EP300 and H3K4me1 in the mouse melanocyte cell line melan-a
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
SUBMITTER: Andrew McCallion
PROVIDER: E-GEOD-38498 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Melanoma genomes are often characterized by large numbers of sunlight-induced mutations. However, epigenetic alterations, in the form of aberrant DNA methylation patterns, are also abundant. Using MIRA-seq, we have carried out a comprehensive characterization of the DNA methylome in a series of metastatic melanoma samples and catalogued the methylation changes relative to normal melanocytes, the presumed cells of origin for these tumors. Individual melanoma tumors contained up to several thousand hypermethylated regions. We discovered 179 tumor-specific methylation peaks that were present in all (27/27) melanomas and may lend themselves as effective disease biomarkers, and 3124 methylation peaks were present in >40% of the tumors. We specifically examined the relationship between presence of the Polycomb mark, H3K27me3 in melanocytes and tumor-specific DNA methylation in melanoma. We found that 150 of the approximately 1,200 tumor-associated methylation peaks near transcription start sites (TSS) were H3K27me3-marked in melanocytes. Notably, DNA methylation in melanoma was specific for distinct H3K27me3 peaks rather than for H3K27me3-enriched regions with broad genomic coverage. Yet, there were also numerous H3K27me3 peak-associated TSS regions that were completely resistant to DNA methylation in tumors. Furthermore, a rather large group of genes became methylated in melanoma but lacked H3K27me3 in melanocytes. There was no relationship between presence of BRAF V600 mutations and the number of methylation peaks in individual tumors. Gene expression analysis showed a strong signature of upregulated immune response genes in melanomas presumably as a result of lymphocyte infiltration. Genes down-regulated in tumors were enriched for melanocyte differentiation and pigmentation factors. Overall, there was limited correlation between tumor-associated DNA methylation changes and changes in gene expression although distinct melanocyte differentiation genes including KIT, PAX3 and SOX10 became methylated and downregulated in melanoma. Examination of H3K27me3 histone modification in human normal melanocytes.
2016-03-31 | E-GEOD-71692 | biostudies-arrayexpress
Project description:Tissue-specific differentiation programs become dysregulated during cancer evolution. The transcription factor Nkx2-1 is a master regulator of pulmonary differentiation that is downregulated in poorly differentiated lung adenocarcinoma. Here we use conditional murine genetics to study the fate of lung epithelial cells upon loss of their master cell fate regulator. Nkx2-1 deletion in normal and neoplastic lung causes not only loss of pulmonary identity but also gastric transdifferentiation. Nkx2-1 maintains pulmonary identity by sequestering the Foxa1 transcription factor at lung-specific loci and by inhibiting Foxa1 binding to gastrointestinal targets. Murine Nkx2-1-negative lung tumors mimic the mucinous subtype of human lung adenocarcinoma, which also exhibits gastric transdifferentiation. Nkx2-1-negative lung adenocarcinomas are dependent on the gastrointestinal gene Hnf4a for efficient initiation. Thus, loss of Nkx2-1 causes transdifferentiation rather than stable dedifferentiation in vivo, suggesting that inactivation of both active and latent differentiation programs are required for tumors to reach a primitive, dedifferentiated state. ChIP-seq data from murine lung adenocarcinomas on (i) transcription factors Nkx2-1 and Foxa in Nkx2-1-deleted tumors and Nkx2-1-positive control tumors, and (ii) four histone marks in Nkx2-1-deleted tumors and Nkx2-1-positive control tumors. (All samples in duplicate and with input controls, i.e. (2 x [(3+3) + (2+8)]) - 1 = 31 samples total - 1 input control used for transcription factor and histone mark, GSM1059357)
2013-04-09 | E-GEOD-43252 | biostudies-arrayexpress
Project description:We performed ChIP-Seq analysis of SOX10, histone H3 lysine 27 acetylation (H3K27ac) and H3K27 trimethylation (H3K27me3) in melanocytes to profile the genomic binding sites of SOX10 and the chromatin landscape. In parallel, we generated Sox10 haploinsufficient cell lines using gene knockout approaches and conducted microarray gene expression analysis to identify functional gene targets of SOX10 transcriptional regulation in melanocytes. We demonstrate that SOX10 predominantly engages “open” chromatin, binds to melanocyte enhancer elements and plays a central role in transcriptional activation and repression of functionally distinct classes of genes. Furthermore, we identified cis-regulatory sequence motifs of putative co-regulatory transcription factors that define SOX10-activated and SOX10-repressed target genes. Our results uncover novel mechanisms and roles of SOX10 in global transcriptional regulation of diverse regulatory pathways in the melanocyte lineage. ChIP-seq profiling of SOX10, H3K27ac, and H3K27me3 in the mouse melanocyte cell line melan-Ink4a-Arf-1 (melan-a).
2015-07-03 | E-GEOD-69949 | biostudies-arrayexpress
Project description:Enhancers act to regulate cell type specific gene expression by facilitating the transcription of target genes. In mammalian cells active or primed enhancers are commonly marked by monomethylation of Histone H3 at lysine 4 (H3K4me1) in a cell-type specific manner. Whether and how this histone modification regulates enhancer-dependent transcription programs in mammals has been unclear. In the present study, we conducted SILAC Mass-spec experiments with mono-nucleosomes and identified multiple H3K4me1 associated proteins, including proteins involved in chromatin remodeling. We demonstrate that H3K4me1 augments the association of the chromatin remodeling complex BAF to enhancers in vivo. Furthermore we show that in vitro, H3K4me1 nucleosomes are more efficiently remodeled by the BAF complex. Crystal structures of a BAF component BAF45c further reveal that monomethylation, but not trimethylation, is accommodated in this protein’s H3K4 binding site. Our results suggest that H3K4me1 plays an active role at enhancers by facilitating the binding of the BAF complex and possibly other chromatin regulators.
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Project description:To study the epigenetic regulation of intestinal epithelium we focus on the role of chromatin modulators. Lysine-specific histone demethylase 1a (KDM1A, LSD1) is one of the enzymes that can erase the H3K4me1/2 mark. To assess the role of LSD1 in intestinal epithelium we studied wild type (WT) (Villin-Cre -; Lsd1f/f) and intestinal-epithelial-specific knock-out (KO) (Villin-Cre+; Lsd1f/f) mice. We found that KO mice completely lack Paneth cells, and have altered stem cell characteristics compared to WT littermates. To assess genome-wide H3K4me1/2 levels in WT and KO small intestines, we sorted small intestinal crypt cells, fixed them, isolated chromatin, and performed ChIP using an H3K4me1 and an H3K4me2 antibody as described in the protocols.
2020-11-16 | E-MTAB-7871 | biostudies-arrayexpress
Project description:To assess the role of H3K4me1 in development in mouse small intestinal epithelium, we isolated intestinal epithelium tissue from wild type mice at E18.5, P7 and P21. This tissue was digested to single cells, sorted, fixed, isolated chromatin, and performed ChIP using an H3K4me1 antibody as described in the protocols.
2020-11-16 | E-MTAB-8710 | biostudies-arrayexpress
Project description:One of the major primary features of the neurocutaneous genetic disorder Neurofibromatosis type 1 are the hyperpigmentary café-au-lait macules where dysregulation of melanocyte development, proliferation and differentiation is considered to play a key etiopathogenic role. To gain better insight in the possible role of the tumor suppressor gene NF1, a transcriptomic microarray analysis was performed on human NF1 heterozygous (NF1+/-) melanocytes of a Neurofibromatosis type 1 patient and NF1 wild type (NF1+/+) melanocytes of a healthy control patient, both cultured from normally pigmented and hyperpigmented lesional café-au-lait skin. Out of 13,850 unique genes, a total of 137 had a significant twofold or more up- (72) or down-regulated (65) expression in NF1+/- melanocytes compared to NF1+/+ melanocytes (genotype effect). Considering possible intrinsic genetic variation in lesional skin, melanocytes showed a total of 51 genes having a significant twofold or more up- (37) or down-regulated (14) expression when they were cultured from hyperpigmentary café-au-lait skin compared to normally pigmented skin (lesional skin type effect). NF1+/- café-au-lait skin melanocytes showed 468 genes with a significant two-fold or more up- (183) or down-regulated (285) expression going beyond the sum of the separate main effects (interaction). Detailed analysis enabled the identification of several modulated genes in NF1+/- (café-au-lait skin) melanocytes, mainly involved in controlling cell proliferation and cell maintenance, in cell adhesion and, surprisingly, in the immune response. An interesting finding was that a high number of transcription factor genes were differentially modulated, among which a specific subset - important in melanocyte-lineage development - showed downregulation in a transcriptional cis-regulatory network governing the activation of the melanocyte-specific dopachrome tautomerase (DCT) gene.
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2013-06-01 | E-GEOD-45226 | biostudies-arrayexpress