The histone demethylase KDM1A sustains the oncogenic potential of MLL-AF9 leukemia stem cells
ABSTRACT: This SuperSeries is composed of the following subset Series: GSE36346: The histone demethylase KDM1A sustains the oncogenic potential of MLL-AF9 leukemia stem cells (ChIP-Seq data) GSE36347: The histone demethylase KDM1A sustains the oncogenic potential of MLL-AF9 leukemia stem cells (expression data) Refer to individual Series
Project description:Using a mouse model of human MLL-AF9 leukemia, we identified the lysine-specific demethylase KDM1A (LSD1 or AOF2) as an essential regulator of leukemia stem cell (LSC) potential. KDM1A acts at genomic loci bound by MLL-AF9 to sustain expression of the associated oncogenic program, thus preventing differentiation and apoptosis. In vitro and in vivo pharmacologic targeting of KDM1A using tranylcypromine analogues active in the nanomolar range phenocopied Kdm1a knockdown in both murine and primary human AML cells exhibiting MLL translocations. By contrast, the clonogenic and repopulating potential of normal hematopoietic stem and progenitor cells was spared. Our data establish KDM1A as a key effector of the differentiation block in MLL leukemia which may be selectively targeted to therapeutic effect. To investigate the effects of Kdm1a KD on histone modifications, we performed chromatin immunoprecipitation followed by next-generation sequencing (ChIP-Seq) in control and Kdm1a KD MLL-AF9 AML cells for dimethyl-H3K4 and dimethyl-H3K9, as well as for trimethyl-H3K4 and trimethyl-H3K9. Dimethyl-H3K4 and dimethyl-H3K9 are targeted for demethylation by KDM1A. For each of these histone modifications, we compared the mean ChIP-Seq signal across and around protein coding genes bound by the MLL-AF9 oncoprotein (Bernt et al., 2011) with the mean signal from genes not bound by MLL-AF9 expressed at high, middle or low levels.
Project description:The MLL gene is a common target of chromosomal translocations found in human leukemia. MLL-fusion leukemias are consistently poor prognosis. One of the most common translocation partners is AF9 (a.k.a. MLLT3). MLL-AF9 recruits DOT1L, a histone 3 lysine 79 methyltransferase (H3K79me1/me2/me3), leading to aberrant gene transcription. We show that DOT1L has three AF9 binding sites, and present the NMR solution structure of a DOT1L-AF9 complex. We generated structure-guided point mutations with graded effects on recruitment of DOT1L to MLL-AF9. ChIP-Seq analyses of H3K79me2 and H3K79me3 show that graded reduction of the DOT1L interaction with MLL-AF9 results in selective losses in H3K79me2 and me3 marks at MLL-AF9 target genes. Furthermore, the degree of DOT1L recruitment defines the level of MLL-AF9 hematopoietic transformation. Hematopoietic progenitor cells isolated from mouse bone marrow were transduced with retrovirus expressing either wildtype MLL-AF9 (WT), mutants, MLL-AF9 (D544R) and MLL-AF9 (D546R). ChIP-Seq analyses were performed on these wildtype and mutant cells using H3K79me2 and H3K79me3 antibodies. 3 samples corresponding to ChIP-Seq with H3K79me2 antibody: 1) MLL-AF9 (WT) 2) MLL-AF9 (D544R) 3) MLL-AF9 (D546R) 3 Samples Corresponding to ChIP-Seq with H3K79me3 antibody: 4) MLL-AF9 (WT) 5) MLL-AF9 (D544R) 6) MLL-AF9 (D546R)
Project description:Activity-dependent transcription influences neuronal connectivity, but the roles and mechanisms of inactivation of activity-dependent genes have remained poorly understood. Genome-wide analyses in the mouse cerebellum revealed that the nucleosome remodeling and deacetylase (NuRD) complex deposits the histone variant H2A.z at promoters of activity-dependent genes, thereby triggering their inactivation. Purification of translating mRNAs from synchronously developing granule neurons (Sync-TRAP) showed that conditional knockout of the core NuRD subunit Chd4 impairs inactivation of activity-dependent genes when neurons undergo dendrite pruning. Chd4 knockout or expression of NuRD-regulated activity genes impairs dendrite pruning. Imaging of behaving mice revealed hyperresponsivity of granule neurons to sensorimotor stimuli upon Chd4 knockout. Our findings define an epigenetic mechanism that inactivates activity-dependent transcription and regulates dendrite patterning and sensorimotor encoding in the brain. One or two replicates of the histone modifications (H3K27me3 and H2A.z), total histone proteins (H2A.z and H3), and ATPase Chd4 using postnatal day 22 cerebella from wild type (WT) or Chd4 conditional knockout (cKO) mice were examined using libraries prepared with the Illumina ChIP-Seq DNA Sample Prep Kit. Four replicates of total RNA were extracted from postnatal day 27-28 cerebella from rotarod-trained or control homecage mice, or Chd4 cKO or WT mice using Trizol and reverse-transcribed with oligo-dT priming. Three replicates of immunoprecipitated Sync-TRAP RNA or the input control using postnatal day 12 Chd4 cKO or WT cerebella were purified and amplified with Ovation RNA-Seq System V2 (NuGEN). All samples were sequenced on the Illumina HiSeq 2000 platform.
Project description:Commitment of hematopoietic stem cells to B lineage precursors and development of B lineage precursors into mature B cells is attained through the coordinated function of multiple signaling networks, which are in turn controlled through stringent functioning of stage-specific transcription factors. Here, we describe the essential role of Sox4, an HMG (high mobility group)-box-containing transactivator, in B cell development. In the absence of Sox4, differentiation from pre-pro B to pro-B, from pro-B fraction B to pro-B fraction C and further to the immature B cell stage was severely impaired. Loss of differentiation was associated with reduced expression of Rag1 and Rag2 and markedly reduced DJ (diverse, joining) and VDJ (variable DJ) recombination at immunoglobulin heavy chain gene loci. We uncovered Sox4-regulated transcriptional circuits and a landscape of Sox4-chromatin interactions in pro-B cells. Sox4 ensured the negative regulation of Wnt signaling, which is critical for self-renewal of hematopoietic stem cells and early progenitors, by inducing one of its downstream effectors, casein kinase 1 epsilon. Our findings suggest that Sox4 orchestrates a unique transcriptional program and coordinates multilevel control in the differentiation of early-stage B cells. One sample of BAP-Sox4 bioChIP DNA and one sample of BAP-Sox4 input chromatin DNA were used.
Project description:In this study, we resolved the genome-wide binding of TR4 in differentiating human erythroid cells by performing chromatin immunoprecipitation followed by next-generation sequencing (ChIP-seq). We found that TR4 preferentially binds to DR1 elements in the promoters of its target genes, and that the majority of these genes encode proteins that participate in fundamental biological functions such as mRNA processing, translation, RNA splicing and primary metabolic process. Interestingly, we also found an increased occurrence of other repeat element motifs (such as DR4, IR1 and ER6) at TR4-bound distal sites that are located more than 10 Kbp away from the nearest gene. This raises the tantalizing possibility that TR4 may heterodimerize with unique partners, including other nuclear receptors such as RXR, thus allowing TR4 to elicit unique transcriptional responses when acting at proximal (promoter) and distal (enhancer and silencer) regulatory sites during human erythropoiesis. Examination of TR4 genome wild binding in human erythroid cells, which are harvested at day 8, 11 and 14 during in vitro differentiation. Two replicates were included for each differentiation stage.
Project description:Epithelial cell adhesion molecule (EpCAM), a membrane protein known to modulate cell-cell adhesion, is also a signaling molecule internalized into the nucleus for transcriptional regulation. Here we demonstrate that activated EGF/EGFR is a signaling factor to drive the proteolysis of EpCAM. Cleavage of the extracellular fragment EpEX results in topographic fading of cell-surface EpCAM detected by antibody-conjugated cantilevers of atomic force microscope (AFM). As a result, internalization of the cytoplasmic domain EpICD forms a transcription factor complex with LEF1 that regulates gene transcription for enhanced cell-mobility functions. Comprehensive probing of cell surface using AFM tip (without antibody) reveals increased elasticity and non-stickiness of these cells, promoting epithelial to mesenchymal transition. While EpCAM cleavage may contribute to the loss of cell-surface adhesiveness, its internalized EpICD additionally regulates targets for promoting cell migration. Thus, this EGF/EGFR-modulated action on structural EpCAM and regulatory EpICD can enhance invasion potential of transformed cells. RL95-2 were stimulated with EGF for 0,12,24,and 48 hr.Immunoprecipitation was carried out using antibodies against EpCAM and Lef-1, sequenced by Illumina HiSeq 2000
Project description:This dataset contains whole-genome RNA sequencing results from cortical neuronal cultures and serves as the basis for characterization of extra-coding RNA species from neuronal systems. This experiment contains six biological samples, each of which underwent PolyA+ and PolyA- RNA-seq. Samples were either unstimulated (i.e., treated with media alone; samples V1 and V2), stimulated with 25mM potassium chloride for 1hr (K1, K2) or inactivated with tetrodotoxin for 1hr (T1, T2). Datasets were obtained using RNA-seq from PolyA+ fractions or PolyA- fractions of RNA. PolyA- fractions are denoted "ec". Thus, 12 samples are listed here due to the difference in RNA library preparation.
Project description:Transcription initiation involves the recruitment of basal transcription factors to the core promoter. A variety of core promoter elements exists, however for most of these motifs the distribution across species is unknown. Here we report on the comparison of human and amphibian promoter sequences. We have used oligo-capping in combination with deep sequencing to determine transcription start sites in Xenopus tropicalis. To systematically predict regulatory elements we have developed a de novo motif finding pipeline using an ensemble of computational tools. A comprehensive comparison of human and amphibian promoter sequences revealed both similarities and differences in core promoter architecture. Some of the differences stem from a highly divergent nucleotide composition of Xenopus and human promoters. Whereas the distribution of some core promoter motifs is conserved independent of species-specific nucleotide bias, the frequency of another class of motifs correlates with the single nucleotide frequencies. This class includes the well-known TATA box and SP1 motifs, which are more abundant in Xenopus and human promoters, respectively. While these motifs are enriched above the local nucleotide background in both organisms, their frequency varies in step with this background. These differences are likely adaptive as these motifs can recruit TFIID to either CpG island or sharply initiating promoters. Our results highlight both conserved and diverged aspects of vertebrate transcription, most notably showing co-opted motif usage to recruit the transcriptional machinery to promoters with diverging nucleotide composition. This shows how sweeping changes in nucleotide composition are compatible with highly conserved mechanisms of transcription initiation. ChIP-seq profiles of TBP in Xenopus tropicalis stage 12 embryos and TSS-seq profiles of Xenopus oocytes and stage 12 embryos
Project description:The interior of the neuronal cell nucleus is a highly organized 3-dimensional (3D) structure in which regions of the genome that are millions of bases apart participate in specialized sub-structures with dedicated functions. To investigate neuronal chromatin organization and dynamics in vivo, we generated bitransgenic mice that express histone GFP-tagged H2B in principal neurons of the forebrain. Surprisingly, the expression of this chimeric histone in mature neurons causes chromocenter declustering and disrupts the association of heterochromatin with the nuclear lamina. The loss of these structures does not affect neuronal viability but is associated with specific transcriptional and behavioral deficits related to serotonergic dysfunction. Overall, our results demonstrate that the 3D-organization of chromatin in the neuronal nucleus supports an additional level of epigenetic regulation of gene expression that critically influences neuronal function and indicate that some loci associated with neuropsychiatric disorders may be particularly sensitive to changes in chromatin architecture. Genome-wide profiling by high throughput sequencing of H3K27me3 in the adult hippocampus of CaMKII-tTA/tetO-H2BGFP (H2BGFP) and their wild-type littermates mice (WT). Chromatin immunoprecipitation (ChIP) was carried out using pooled hippocampal tissue from 3 mice (one hippocampus per mouse). One DNA library was constructed per genotype. Each DNA library was prepared from pooled immunoprecipitated DNA from 4 independent ChIP assays. In total, tissue from 12 different mice was used to prepare each DNA library. 60% of a lane was used to perform single end (1x50bp) multiplex sequencing in HiSeq 2500 apparatus (Illumina). Each library, was sequenced in duplicate (in two independent sequencing runs. Technical replicates).
Project description:FOXM1 is a key transcription factor regulating cell cycle progression, DNA damage response, and a host of other hallmark cancer features, but the role of the FOXM1 cistrome in driving estrogen receptor-positive (ER+) vs. ER- breast cancer clinical outcomes remains undefined. Chromatin immunoprecipitation sequencing (ChIP-Seq) coupled with RNA sequencing (RNA-Seq) analyses was used to identify FOXM1 target genes in breast cancer cells (MCF-7) where FOXM1 expression was either induced by cell proliferation or repressed by p53 upregulation.