Homo sapiens
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ABSTRACT:
PROVIDER: PRJNA352395 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:To analyze the change of global transcriptome landscape among proneural and mesenchymal GSCs, after the transient knockdown of polycomb repressor complex and upon deregulations of miR-128 in different subtypes of GSCs
2017-04-30 | GSE89501 | GEO
Project description:Polycomb group (PcG) proteins including EZH2, SUZ12 ,BMI1,CBX8 and so on, which specifically catalyze trimethylation of histone 3 lysine 27 (H3K27me3), and methylated H3K27 can be recognized by other specific binding proteins to compress chromatin structure, leading to the transcriptional repression of the target genes. To explore a potential functional implication of PcG components in HCC, we stably transfected HepG2 cells with either vectors or constructs expressing shRNA that specifically targets EZH2, SUZ12, BMI1, or CBX8. A cDNA microarray analysis was performed on shRNA KDs of EZH2, SUZ12, BMI1, or CBX8 HepG2 cells. To obtain a broader understanding of the molecular network of PcG in HCC, the whole genome microarray expression profiling was performed on shRNA KDs of EZH2, SUZ12, BMI1, or CBX8 HepG2 cells. Comparison of gene expression results from shRNA KDs of EZH2, SUZ12, BMI1 or CBX8 HepG2 cells.
2014-01-16 | E-GEOD-54108 | biostudies-arrayexpress
Project description:Polycomb group (PcG) proteins including EZH2, SUZ12 ,BMI1,CBX8 and so on, which specifically catalyze trimethylation of histone 3 lysine 27 (H3K27me3), and methylated H3K27 can be recognized by other specific binding proteins to compress chromatin structure, leading to the transcriptional repression of the target genes. To explore a potential functional implication of PcG components in HCC, we stably transfected HepG2 cells with either vectors or constructs expressing shRNA that specifically targets EZH2, SUZ12, BMI1, or CBX8. A cDNA microarray analysis was performed on shRNA KDs of EZH2, SUZ12, BMI1, or CBX8 HepG2 cells. To obtain a broader understanding of the molecular network of PcG in HCC, the whole genome microarray expression profiling was performed on shRNA KDs of EZH2, SUZ12, BMI1, or CBX8 HepG2 cells.
2014-01-16 | GSE54108 | GEO
Project description:EBV proteins EBNA3A, EBNA3B and EBNA3C control hundreds of host genes after infection. Changes in epigenetic marks around EBNA3-regulated genes suggest they exert transcriptional control in collaboration with epigenetic factors. The roles of PRC2 subunit SUZ12 and of PRC1 subunit BMI1 were assessed for their importance in EBNA3-mediated repression and activation. ChIP-seq experiments for SUZ12 and BMI1 were performed to determine their global localization on chromatin and analysis offered further insight into polycomb protein distribution in differentiated cells. Their localization was compared to that of each EBNA3, to resolve longstanding questions about the EBNA3-polycomb relationship. SUZ12 did not co-localize with any EBNA3, whereas EBNA3C co-localized significantly and co-immunoprecipitated with BMI1. In cells expressing a conditional EBNA3C, BMI1 was sequestered to EBNA3C binding sites after EBNA3C activation. When SUZ12 or BMI1 was knocked down in the same cells, SUZ12 did not contribute to EBNA3C-mediated regulation. Surprisingly, after BMI1 knock down, EBNA3C repressed equally efficiently, but host gene activation by EBNA3C was impaired. This overturns previous assumptions about BMI1/PRC1 functions during EBNA3C-mediated regulation, for the first time identifies directly a host factor involved in EBNA3-mediated activation and provides a new insight of how PRC1 can be involved in gene activation.
2018-10-14 | GSE119823 | GEO
Project description:We report that these features are associated with distinct transcriptional programs, with vascular regions showing a proneural profile and hypoxic regions a mesenchymal pattern. As these regions harbor glioma stem cells (GSCs), we investigated the epigenetic regulation of these two niches. Proneural, perivascular GSCs activated EZH2, whereas mesenchymal GSCs in hypoxic regions expressed BMI1 protein. To determine the differential regional activation of EZH2 and BMI1 function, we performed chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) with H3K27me3 (histone modification by EZH2) or H2AK119Ub (histone modification by BMI1) antibodies in CD15-postive GSCs from enhancing and necrotic regions of two GBM specimens, and found over 80% of regional specific target genes displayed distinct H3K27me3 or H2AK119Ub marks, indicating distinct PRC function in GSCs residing in different regions. H3K27me3, generally associated with inhibition of transcription, marked neuronal and cellular development targets in both the enhancing and necrotic regions, albeit without substantial overlap in gene identity, with EZH2/SUZ12/H3K27me3 targets most significantly in the enhancing regions. In contrast, H2AK119Ub marked very different targets in the enhancing and necrotic regions, with H2AK119Ub in CD15-positive GSCs from the hypoxia (necrotic) regions marking genes strongly associated with mesenchymal subtype signaling pathways, such as TGFb, NFkB, and WNT, indicating probable microenvironment-specific functions of EZH2 and BMI1.
2017-10-01 | GSE103274 | GEO
Project description:Glioblastoma (GBM) is the most common and aggressive primary brain tumor with limited therapeutic options, possibly because of the highly tumorigenic subpopulations of stem cell-like cells. Mechanisms that sustain cancer stem cells are crucial to tumor progression. The polycomb group protein BMI1 (BMI1 proto-oncogene, polycomb ring finger) maintains cancer hallmarks including the glioblastoma stem-like cell (GSC) state. Ubiquitin-specific protease 22 (USP22) is highly expressed in and required for the maintenance of cancer stem cells (CSCs). Previously, we observed that forced expressed microRNA-218 in glioblastoma cells led to suppressed BMI1 expression. However, the pathways engaged by USP22 or driving BMI1 accumulation in GSCs remained elusive. Here, we found USP22 to be a novel deubiquitylase of BMI1. USP22 directly deubiquitylates and stabilizes BMI1. USP22 protein levels are elevated in tumor neurosphere. USP22 depletion induces BMI1 destabilization, and results in the inhibition of GSCs self-renewal by regulating a broad range of genes involved in glioma stemness and progression. Xenograft analyses using U87MG cells showed that both USP22 and BMI1 depletion attenuated tumor growth. Clinically, the expression levels of USP22 and BMI1 were positively correlated with those common targets like POSTN, HEY2, or PDGFRA and inversely correlated with ATF3 in human glioblastoma specimens. Taken together, our data reveals that USP22 functions as a novel deubiquitylase of BMI1 and inhibits self-renewal of GSCs by stabilizing BMI1. These findings also indicate that the USP22-BMI1 axis has a critical role in glioma tumorigenesis and that targeting the axis may provide a new therapeutic approach for human glioblastoma.
2017-01-01 | GSE89239 | GEO
Project description:Polycomb group (PcG) proteins are essential for accurate axial body patterning during embryonic development. PcG-mediated repression is conserved in metazoans and is targeted in Drosophila by Polycomb response elements (PREs). Targeting sequences in humans have not been described. While analyzing chromatin architecture in the context of human embryonic stem cell (hESC) differentiation, we discovered a 1.8kb region between HOXD11 and HOXD12 (D11.12) that is associated with PcG proteins, is nuclease hypersensitive, and shows alteration as hESCs differentiate. D11.12 repressed luciferase expression from a reporter construct both before and after differentiation of mesenchymal stem cells into adipocytes. Full repression by D11.12 required a highly conserved region and YY1 binding sites. Repression relied upon PcG proteins Bmi1 and Eed and a YY1-interacting partner, RYBP. We conclude that D11.12 is a Polycomb-dependent regulatory region with similarities to Drosophila PREs, indicating conservation in the mechanisms that target PcG function in mammals and flies. Data contains microarray measurements of the MNase-digested mononucleosomal fragments in hES cells, derived MSCs, osteoblasts and adipocytes. The ChIP-chip data includes Suz12, Bmi1 and H3K27me3 measurements in MSCs and adipocytes.
2010-06-19 | E-GEOD-19046 | biostudies-arrayexpress
Project description:Glioblastomas are lethal cancers defined by angiogenesis and pseudopalisading necrosis. Here, we demonstrate that these features are associated with distinct transcriptional programs, with vascular regions showing a Proneural profile and hypoxic regions a Mesenchymal pattern. As these regions harbor glioma stem cells (GSCs), we investigated the epigenetic regulation of these two niches. Proneural, perivascular GSCs activated EZH2, whereas Mesenchymal GSCs in hypoxic regions expressed BMI1 protein, which promoted cellular survival under stress. Using both genetic and pharmacologic inhibition, we found that Proneural GSCs are selectively sensitive to EZH2 disruption, whereas Mesenchymal GSCs are sensitive to BMI1 inhibition. Given that glioblastomas contain both Proneural and Mesenchymal GSCs, combined EZH2 and BMI1 targeting proved more effective than either agent alone both in culture and in vivo, suggesting that strategies that simultaneously target multiple epigenetic regulators within glioblastomas may be necessary to overcome resistance to therapies caused by intratumoral heterogeneity.
2017-10-01 | GSE86237 | GEO
Project description:NguyenLK2011 - Ubiquitination dynamics in
Ring1B-Bmi1 system
This theoretical model investigates the
dynamics of Ring1B/Bmi1 ubiquitination to identify bistable
switch-like and oscillatory behaviour in the
system. Michaelis-Menten (MM) equations are used to formulate
the model. However, the authors show that the dynamics persist even
for Mass-Action kinetics. This SBML file is the MM version of the
model.
This model is described in the article:
Switches,
excitable responses and oscillations in the Ring1B/Bmi1
ubiquitination system.
Nguyen LK, Muñoz-García J,
Maccario H, Ciechanover A, Kolch W, Kholodenko BN.
PLoS Comput. Biol. 2011 Dec; 7(12):
e1002317
Abstract:
In an active, self-ubiquitinated state, the Ring1B ligase
monoubiquitinates histone H2A playing a critical role in
Polycomb-mediated gene silencing. Following ubiquitination by
external ligases, Ring1B is targeted for proteosomal
degradation. Using biochemical data and computational modeling,
we show that the Ring1B ligase can exhibit abrupt switches,
overshoot transitions and self-perpetuating oscillations
between its distinct ubiquitination and activity states. These
different Ring1B states display canonical or multiply branched,
atypical polyubiquitin chains and involve association with the
Polycomb-group protein Bmi1. Bistable switches and oscillations
may lead to all-or-none histone H2A monoubiquitination rates
and result in discrete periods of gene (in)activity. Switches,
overshoots and oscillations in Ring1B catalytic activity and
proteosomal degradation are controlled by the abundances of
Bmi1 and Ring1B, and the activities and abundances of external
ligases and deubiquitinases, such as E6-AP and USP7.
This model is hosted on
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BIOMD0000000622.
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2024-09-02 | BIOMD0000000622 | BioModels
Project description:Suz12(Bgal/Bgal) ESCs express a truncated form of Suz12 fused to Beta-galactosidase. These cells maintain a reduced level of H3K27me3 despite this mutation to a core component of PRC2, unlike Eed-/- ESCs whose H3K27me3 is ablated. Two ESC lines mutant in genes of core components of Polycomb Repressive Complex 2 were assessed for H3K27me3 by ChIP-seq, as compared to a wild type ESC line.
2013-07-22 | E-GEOD-47483 | biostudies-arrayexpress