Ontology highlight
ABSTRACT:
OTHER RELATED OMICS DATASETS IN: GSE12363
PROVIDER: PRJNA113189 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:We created a mouse model where conditional expression of physiologic levels of an Mll-AF4 fusion oncogene induces development of acute lymphoblastic (ALL) or acute myeloid leukemias (AML). ChIP-chip analysis demonstrated increased histone H3 Lysine 79 (H3K79) dimethylation that correlated with Mll-AF4 associated gene expression profiles in murine ALLs, and in human MLL-rearranged leukemias. In addition, human MLL-rearranged ALLs can be distinguished from other ALLs by their genome-wide H3K79 methylation profiles. Keywords: Cell type comparison
2008-11-04 | GSE12361 | GEO
Project description:We created a mouse model where conditional expression of physiologic levels of an Mll-AF4 fusion oncogene induces development of acute lymphoblastic (ALL) or acute myeloid leukemias (AML). ChIP-chip analysis demonstrated increased histone H3 Lysine 79 (H3K79) dimethylation that correlated with Mll-AF4 associated gene expression profiles in murine ALLs, and in human MLL-rearranged leukemias. In addition, human MLL-rearranged ALLs can be distinguished from other ALLs by their genome-wide H3K79 methylation profiles. Keywords: Cell type comparison
2008-11-04 | GSE12362 | GEO
Project description:We created a mouse model where conditional expression of physiologic levels of an Mll-AF4 fusion oncogene induces development of acute lymphoblastic (ALL) or acute myeloid leukemias (AML). ChIP-chip analysis demonstrated increased histone H3 Lysine 79 (H3K79) dimethylation that correlated with Mll-AF4 associated gene expression profiles in murine ALLs, and in human MLL-rearranged leukemias. In addition, human MLL-rearranged ALLs can be distinguished from other ALLs by their genome-wide H3K79 methylation profiles. Keywords: Cell type comparison
2008-11-04 | GSE12360 | GEO
Project description:Understanding the underlying molecular mechanisms of defined cancers is crucial for effective personalized therapies. Translocations of the Mixed Lineage Leukemia (MLL) gene produce fusion proteins such as MLL-AF4 that disrupt epigenetic pathways and cause poor prognosis leukemias. Here we find that MLL-AF4 occupies a subset of unmethylated CG-enriched genes in combination with its cofactors Menin/LEDGF and ENL. MLL-AF4 mainly displays a punctate binding pattern near gene promoters, but we also observe a second less common pattern where MLL-AF4 spreads into the gene body and is associated with increased transcription and increased histone H3 lysine 79 methylation (H3K79me2/3). Compared to other H3K79me2/3 marked genes, MLL-AF4 spreading genes are more sensitive to inhibitors of the H3K79 methyltransferase DOT1L. This sensitivity mediates synergistic interactions with additional targeted drug treatments. Therefore, epigenetic spreading and enhanced susceptibility to epidrugs provides a potential new Achilles heel for guiding combination therapies in humans.
2017-01-12 | GSE83671 | GEO
Project description:Integrative epigenomic analysis identifies biomarkers and therapeutic targets in adult B-acute lymphoblastic leukemia. We performed DNA methylation (HELP array) and gene expression profiling in 215 samples of adult B-lineage acute lymphoblastic leukemia (ALL) and 12 normal preB samples. Adult B-lineage acute lymphoblastic leukemia (B-ALL) is an aggressive disease with <40% long-term survival. Genetic alterations such as BCR/ABL, E2A/PBX1 and MLL rearrangement (tMLL) define distinct B-ALL subtypes, which are associated with poor clinical outcome. It has been shown that these B-ALL subtypes have distinct expression profiles. However, the role of the epigenome in shaping these expression profiles and how the aberrant epigenetic gene regulation contributes to the biological and clinical features of those ALL subtypes is largely unknown. To address this question, we performed genome-wide DNA methylation and gene expression profiling on a large cohort of 215 well-characterized adult B-ALL specimens from the ECOG E2993 phase III clinical trial and a cohort of normal precursor B (preB) cells from 12 healthy bone marrows. The integrative analysis of these profiles led to the identification of key gene networks deregulated at the epigenetic and transcriptional levels within each subtype. In BCR/ABL, we identified a network centered on IL2RA(CD25), which is itself hypomethylated and overexpressed in most BCR/ABL B-ALL and confers poor clinical outcomes. In the tMLL subtype, we uncovered aberrant epigenetic and transcriptional activities that include hypomethylation and upregulation of FLT3 and BCL6. After showing that MLL/AF4 fusion protein binds to these genes as well as other hypomethylated and overexpressed genes in tMLL ALL cells, we showed that a specific BCL6 inhibitor, RI-BPI, kills tumor cells in both tMLL ALL cell lines and patient samples. BCL6 inhibition may therefore represent a novel therapeutic strategy for B-ALL patients with MLL translocations. RUNX1 is a key target gene in MLL-AF4 leukemias and contributes to gene activation by interacting with the AF4-MLL complex. The Mixed Lineage Leukemia 1 protein (MLL1) is an important epigenetic protein that is required for the maintenance of gene activation during development, but is also mutated in a subset of aggressive human leukemias. The most common leukemogenic MLL1 mutations are chromosome translocations that fuse MLL1 in-frame to produce novel fusion proteins. Different MLL1 fusion proteins cause unique leukemias even when they are expressed in the same cell type, suggesting that they function through unique molecular mechanisms. We used ChIP-seq in MLL-AF4 patient cell lines to identify target genes that are involved in leukemogenesis. ChIP-seq using MLLN, AF4, H3K4me3 and H3K79me2 antibodies in RS4;11 cells.
2012-11-27 | E-GEOD-38403 | biostudies-arrayexpress
Project description:The histone 3 lysine 79 (H3K79) methyltransferase Dot1l has been implicated in the development of leukemias bearing translocations that involve the Mixed Lineage Leukemia (MLL) gene. We identified the MLL-fusion targets in a murine MLL-AF9 leukemia model, and conducted epigenetic profiling for H3K79me2, H3K4me3, H3K27me3 and H3K36me3. Histone methylation patterns are highly abnormal on MLL-AF9 fusion target loci, defining a distinct epigenetic lesion involving H3K79. Conditional inactivation of Dot1l leads to specific down-regulation of direct MLL-AF9 targets and an MLL-translocation associated gene expression signature, while global transcription levels remain largely unaffected. This correlated with a greater sensitivity of leukemic blasts towards loss of Dot1l compared to normal hematopoietic cells. Development of in vivo leukemia was absolutely dependent on Dot1l. Chromatin immunoprecipitation followed by Solexa sequencing for H3K4me3, H3K27me3, H3K36me3, H3K79me2 and biotinylated MLL-AF9 in HSC, GMP and LSC.
2011-09-13 | E-GEOD-29130 | biostudies-arrayexpress
Project description:Aberrant Hox gene activation is a recurrent feature in several different types of human leukemia, including leukemias with rearrangements of the mixed lineage leukemia (MLL) gene. In this study, we demonstrate that Hox gene expression is controlled by higher degree H3K79 methylation in acute myeloid leukemia (AML). We show that the deposition of progressive H3K79 methylation states at the genomic loci of critical Hox genes is dependent on the interaction of the H3K79 methyltransferase Dot1l with Af10, a protein that is found in the Dot1l complex isolated from diverse cell types. Furthermore, abrogation of the Dot1l-Af10 interaction reverses aberrant epigenetic profiles found in the leukemia epigenome and impairs the transforming ability of mechanistically distinct AML oncogenes. Primary MLL-AF9 leukemias in the AF10 floxed background (homozygous) were transduced with MSCV-IRES-tdTomato (MIT) or the Cre recombinase expressing MIT vector, cells were sorted and injected into secondary recipient mice to generate Af10 floxed (MIT) or deleted (CRE) leukemias. BM cells fresly harvested from these leukemias were sorted for tdTomato expression and used for microarrays. BM cells from Hoxa9-Meis1 transduced primary leukemias were used for comparison.
2014-09-08 | E-GEOD-54499 | biostudies-arrayexpress
Project description:The histone 3 lysine 79 (H3K79) methyltransferase Dot1l has been implicated in the development of leukemias bearing translocations that involve the Mixed Lineage Leukemia (MLL) gene. We identified the MLL-fusion targets in a murine MLL-AF9 leukemia model, and conducted epigenetic profiling for H3K79me2, H3K4me3, H3K27me3 and H3K36me3. Histone methylation patterns are highly abnormal on MLL-AF9 fusion target loci, defining a distinct epigenetic lesion involving H3K79. Conditional inactivation of Dot1l leads to specific down-regulation of direct MLL-AF9 targets and an MLL-translocation associated gene expression signature, while global transcription levels remain largely unaffected. This correlated with a greater sensitivity of leukemic blasts towards loss of Dot1l compared to normal hematopoietic cells. Development of in vivo leukemia was absolutely dependent on Dot1l.
2011-09-13 | GSE29130 | GEO
Project description:We report the genome wide distribution of H3K79 dimethylation in mouse MLL-AF6 positive leukemias to assess whether this epigenetic mark drives MLL-target gene expression. Examination of H3K79 dimethylation in bone marrow cells from sacrificed terminally ill MLL-AF6 positive leukemic mice. The retroviral MSCV-IRES-neo-MLL-AF6 construct was transduced into mouse bone marrow lineage negative Kit +, Sca + (LSK) cells and these cells were injected after G418 selection into irradiated syngenic mice to establish MLL-AF6 positive leukemias.
2013-04-03 | E-GEOD-43062 | biostudies-arrayexpress
Project description:We report the genome wide distribution of the three states of H3K79 methylation (H3K79me1/me2/me3) and H3K27me3 in mouse lineage negative Sca-1 positive Kit positive cells (LSKs), granulocyte macrophage progenitors (GMPs) and LSK derived MLL-AF9 leukemias in the presence or absence of the Af10 OM-LZ domain. Legend- MIT:MSCV-IRES-tdTomato (Empty vector control) and CRE (MIT vector with the Cre recombinase). We examined the H3K79 me1,me2,me3 and H3K27me3 profiles by ChIP-seq in lineage negative Sca-1 positive, Kit positive (LSK) cells, granulocyte macrophage progenitors (GMPs) and bone marrow cells from sacrificed terminally ill secondary MLL-AF9 positive leukemic mice. In case of the MLL-AF9 leukemias, the ChIP-seq experiments were performed in 2 conditions in the presence or absence of the Dot1l interacing octapeptide-motif leucine zipper (OM-LZ) domain of Af10. For the leukemia experiments, leukemias derived from the Af10 OM-LZ homozygous floxed background were transduced with MSCV-IRES-tdTomato control vector (MIT) or its Cre-recombinase expressing counterparts (CRE). Subsequently, we sorted tdTomato positive cells and injected them into sub-lethally irradiated syngenic secondary recipient mice. Seconday leukemias obtained from these MIT or CRE expressing cells were used for ChIP -seq studies.
2014-09-08 | E-GEOD-55038 | biostudies-arrayexpress