The histone demethylase KDM1A sustains the oncogenic potential of MLL-AF9 leukemia stem cells
Ontology highlight
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:This study report that miR-150, a key hematopoietic regulatory microRNA (miRNA) and one of the most downregulated miRNAs in MLL-associated leukemias, acts as a tumor suppressor to block the leukemogenic potency of leukemic stem cells. When expression of miR-150 was restored, a significantly suppressed leukemic stem cell potency of MLL-AF9 cells was observed both in vivo and in vitro. To investigate the tumor suppressive function of miR-150 in MLL-AF9 cells, we isolated three batches of MLL-AF9 cells infected with MDH empty vector or MDH-miR-150 expression retrovirus. Total RNA were extracted and applied for Agilent array analysis. Gene profiling analysis demonstrated that elevated miR-150 altered various aspects of gene expression patterns in MLL-AF9 cells, including stem cell signatures, cancer pathways, and cell survival. miR-150-MLL-AF9 and MDH-MLL-AF9 isolated cells were compared for gene expression patterns. Triplicates using three batches of FACS sorted cells were compared in pairs on the array. MDH-MLL-AF9 samples were labeld with Cy3 and miR-150-MLL-AF9 samples were labled with Cy5.
Project description:We studied the chromatin modification patterns induced by the presence of the MLL-AF9 fusion protein in a model of human hematopoietic stem/progenitor cells (HSPC) transduced with retrovirus expressing MLL-AF9cDNA (HSPC-MA9). Comparative ChIP-seq analysis between HSPC-MA9 and control HSPC, revealed a massive hyperacetylation of histones that was consistent with the transcriptional profile in the presence of MLL-AF9 fusion protein. Furthermore, we identified 66 MLL-AF9 targets, and found that H4ac was present along with H3K4me3 and H3K79me2 chromatin marks in over 50% of the MLL-AF9 target genes. Examination of histone aceylation and methylation changes upon expression of MLL-AF9 fusion protein in human hematopoietic stem/progenitor cells.
Project description:Despite the advanced understanding of disease mechanisms, the current therapeutic regimens fail to cure most patients with acute myeloid leukemia (AML). In the present study, we address the role of protein synthesis control in leukemia function and leukemia propagation. Using a transgenic eIF6 mouse strain that permits inducible and graded regulation of ribosomal subunit joining, we have generated a murine model of MLL-AF9 acute myeloid leukemia where the expression of transgenic eIF6 is doxycycline-inducible. Using this model system, we have performed scRNA-seq expression analysis to study the impact of eIF6 overexpression on leukemia cell function. scRNA-seq was performed using the 10x Chromium Next GEM Single Cell 3ʹ platform. BM cells were harvested from leukemia-engrafted mice that were administered doxycycline for six days and viable GFP+ leukemia cells were sorted into PBS containing 0.05 % BSA following the manusfacturer’s protocol. 5 samples: 2 control and 3 eIF6 overexpression.
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: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: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: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: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.