Epigenetic antagonism between Snf5 and Ezh2 during oncogenic transformation and elevated levels of H3K27me3 in Snf5-deficient cells
Ontology highlight
ABSTRACT:
OTHER RELATED OMICS DATASETS IN: PRJNA133131PRJNA130857PRJNA133129
ORGANISM(S): Mus musculus
PROVIDER: GSE23659 | GEO | 2010/10/19
SECONDARY ACCESSION(S): PRJNA130857
REPOSITORIES: GEO
Similar Datasets
Project description:Epigenetic antagonism between Snf5 and Ezh2 during oncogenic transformation and elevated levels of H3K27me3 in Snf5-deficient cells
| PRJNA130857 | ENA
Project description:Epigenetic alterations have been increasingly implicated in oncogenesis. Analysis of Drosophila mutants suggests that Polycomb and SWI/SNF complexes can serve antagonistic developmental roles. However, the relevance of this relationship to human disease is unclear. Here we have investigated functional relationships between these epigenetic regulators in oncogenic transformation. Mechanistically, we show that loss of the SNF5 tumor suppressor leads to elevated expression of the Polycomb gene EZH2 and that Polycomb targets are broadly H3K27-trimethylated and repressed in SNF5-deficient fibroblasts and cancers. Further, we show antagonism between SNF5 and EZH2 in the regulation of stem cell-associated programs and that Snf5 loss activates those programs. Finally, using conditional mouse models, we show that inactivation of Ezh2 blocks tumor formation driven by Snf5 loss. Mouse Embryonic Fibroblasts (MEFs) conditionally inactivated for Ezh2, Snf5 and Ezh2, or from control WT MEFs were used to evaluated epigenetic antagonism between Snf5 and Ezh2 in the control of gene expression programs. Snf5-deficient lymphoma samples and control CD8+ WT T-cells were used to evaluate genetic programs misregulated by Snf5 inactivation during tumorigenesis. RNA was isolated from each of these samples and used for gene expression profiling on Affymetrix arrays.
2010-10-19 | E-GEOD-23656 | biostudies-arrayexpress
Project description:Epigenetic alterations have been increasingly implicated in oncogenesis. Analysis of Drosophila mutants suggests that Polycomb and SWI/SNF complexes can serve antagonistic developmental roles. However, the relevance of this relationship to human disease is unclear. Here we have investigated functional relationships between these epigenetic regulators in oncogenic transformation. Mechanistically, we show that loss of the SNF5 tumor suppressor leads to elevated expression of the Polycomb gene EZH2 and that Polycomb targets are broadly H3K27-trimethylated and repressed in SNF5-deficient fibroblasts and cancers. Further, we show antagonism between SNF5 and EZH2 in the regulation of stem cell-associated programs and that Snf5 loss activates those programs. Finally, using conditional mouse models, we show that inactivation of Ezh2 blocks tumor formation driven by Snf5 loss.
2010-10-19 | GSE23656 | GEO
Project description:Epigenetic alterations have been increasingly implicated in oncogenesis. Analysis of Drosophila mutants suggests that Polycomb and SWI/SNF complexes can serve antagonistic developmental roles. However, the relevance of this relationship to human disease is unclear. Here we have investigated functional relationships between these epigenetic regulators in oncogenic transformation. Mechanistically, we show that loss of the SNF5 tumor suppressor leads to elevated expression of the Polycomb gene EZH2 and that Polycomb targets are broadly H3K27-trimethylated and repressed in SNF5-deficient fibroblasts and cancers. Further, we show antagonism between SNF5 and EZH2 in the regulation of stem cell-associated programs and that Snf5 loss activates those programs. Finally, using conditional mouse models, we show that inactivation of Ezh2 blocks tumor formation driven by Snf5 loss.
2010-10-19 | GSE23658 | GEO
Project description:Epigenetic alterations have been increasingly implicated in oncogenesis. Analysis of Drosophila mutants suggests that Polycomb and SWI/SNF complexes can serve antagonistic developmental roles. However, the relevance of this relationship to human disease is unclear. Here, we have investigated functional relationships between these epigenetic regulators in oncogenic transformation. Mechanistically, we show that loss of the SNF5 tumor suppressor leads to elevated expression of the Polycomb gene EZH2 and that Polycomb targets are broadly H3K27-trimethylated and repressed in SNF5-deficient fibroblasts and cancers. Further, we show antagonism between SNF5 and EZH2 in the regulation of stem cell-associated programs and that Snf5 loss activates those programs. Finally, using conditional mouse models, we show that inactivation of Ezh2 blocks tumor formation driven by Snf5 loss.
| S-EPMC2957473 | biostudies-literature
Project description:BackgroundIn osteosarcoma (OS), chemotherapy resistance has become one of the greatest issues leading to high mortality among patients. However, the mechanisms of drug resistance remain elusive, limiting therapeutic efficacy. Here, we set out to explore the relationship between dynamic histone changes and the efficacy of cisplatin against OS.ResultsFirst, we found two histone demethylases associated with histone H3 lysine 27 trimethylation (H3K27me3) demethylation, KDM6A, and KDM6B that were upregulated after cisplatin treatment. Consistent with the clinical data, cisplatin-resistant OS specimens showed lower H3K27me3 levels than sensitive specimens. Then, we evaluated the effects of H3K27me3 alteration on OS chemosensitivity. In vitro inhibition of the histone methyltransferase EZH2 in OS cells decreased H3K27me3 levels and led to cisplatin resistance. Conversely, inhibition of the demethylases KDM6A and KDM6B increased H3K27me3 levels in OS and reversed cisplatin resistance in vitro and in vivo. Mechanistically, with the help of RNA sequencing (RNAseq), we found that PRKCA and MCL1 directly participated in the process by altering H3K27me3 on their gene loci, ultimately inactivating RAF/ERK/MAPK cascades and decreasing phosphorylation of BCL2.ConclusionsOur study reveals a new epigenetic mechanism of OS resistance and indicates that elevated H3K27me3 levels can sensitize OS to cisplatin, suggesting a promising new strategy for the treatment of OS.
| S-EPMC6335728 | biostudies-literature
Project description:Snf5 (Ini1/Baf47/Smarcb1), a core member of the Swi/Snf chromatin remodeling complex, is a potent tumor suppressor whose mechanism of action is largely unknown. Biallelic loss of Snf5 leads to the onset of aggressive cancers in both humans and mice. We have developed an innovative and widely applicable analytical technique for cross-species validation of cancer models and show that the gene expression profiles of our Snf5 murine models closely resemble those of human Snf5-deficient rhabdoid tumors. We exploit this system to produce what we believe to be the first report documenting the effects on gene expression of inactivating a Swi/Snf subunit in normal mammalian cells and to identify the transcriptional pathways regulated by Snf5. We demonstrate that the tumor suppressor activity of Snf5 depends on its regulation of cell cycle progression; Snf5 inactivation leads to aberrant up-regulation of E2F targets and increased levels of p53 that are accompanied by apoptosis, polyploidy, and growth arrest. Further, conditional mouse models demonstrate that inactivation of p16Ink4a or Rb (retinoblastoma) does not accelerate tumor formation in Snf5 conditional mice, whereas mutation of p53 leads to a dramatic acceleration of tumor formation.
| S-EPMC1308926 | biostudies-literature
Project description:Background:EZH2 acts as an oncogene through canonical pathway EZH2/H3K27Me3 and uncanonical pathway pAkt1/pS21EZH2 in many solid tumors including ovarian cancer. However, the clinical value of EZH2/H3K27Me3 and pAkt1/pS21EZH2 remain unclear. In the current study, we aim to investigate the correlation between these two pathways to clinical-pathological parameters and prognosis. Methods:EZH2, H3K27Me3, pAkt1 and pS21EZH2 expression were evaluated by tissue micro-array and immunohistochemistry in a cohort of ovarian cancer patients. The results were analyzed based on clinical characteristics and survival outcomes. Results:EZH2, H3K27Me3, pAkt1 and pS21EZH2 were universally expressed in ovarian cancer specimens with a positive expression rate of 81.54% (53/65), 88.89% (48/54), 63.07% (41/65) and 75.38% (49/65). EZH2-pS21EZH2 (Spearman r = 0.580, P < 0.0001) and pS21EZH2-pAkt1 (Spearman r = 0.546, P < 0.0001) were closely correlated while EZH2- H3K27Me3 were less closely correlated (Spearman r = 0.307, P = 0.002). Low pS21EZH2 associated with better chemotherapy response (OR = 0.184; 95% CI [0.052-0.647], P = 0.008) according to logistic regression with an area under the curve of 0.789 (specificity 89.36%, sensitivity 68.42%) by ROC analysis and predicted improved progression-free survival (HR = 0.453; 95% CI [0.229-0.895], P = 0.023) as indicated by multivariate cox regression. A combination of EZH2low/H3K27Me3low status predicted better chemotherapy response (OR = 0.110; 95% CI [0.013-0.906], P = 0.040) and better progression-free survival (HR = 0.388; 95% CI [0.164-0.917], P = 0.031). The results suggested that EZH2/H3K27Me3 and pEZH2 predicted chemotherapy response and progression-free survival in ovarian cancer.
| S-EPMC7227641 | biostudies-literature
Project description:Triple-Negative Breast Cancer (TNBC) has a poor prognosis and adverse clinical outcomes among all breast cancer subtypes as there is no available targeted therapy. Overexpression of Enhancer of zeste homolog 2 (EZH2) has been shown to correlate with TNBC's poor prognosis, but the contribution of EZH2 catalytic (H3K27me3) versus non-catalytic EZH2 (NC-EZH2) function in TNBC progression remains elusive. We reveal that selective hyper-activation of functional EZH2 (H3K27me3) over NC-EZH2 alters TNBC metastatic landscape and fosters its peritoneal metastasis, particularly splenic. Instead of H3K27me3-mediated repression of gene expression; here, it promotes KRT14 transcription by attenuating binding of repressor SP1 to its promoter. Further, KRT14 loss significantly reduces TNBC migration, invasion, and peritoneal metastasis. Consistently, human TNBC metastasis displays positive correlation between H3K27me3 and KRT14 levels. Finally, EZH2 knockdown or H3K27me3 inhibition by EPZ6438 reduces TNBC peritoneal metastasis. Altogether, our preclinical findings suggest a rationale for targeting TNBC with EZH2 inhibitors.
| S-EPMC9708848 | biostudies-literature
Project description:Androgen receptor (AR) is a hormone-activated transcription factor that plays important roles in prostate development and function, as well as malignant transformation. The downstream pathways of AR, however, are incompletely understood. AR has been primarily known as a transcriptional activator inducing prostate-specific gene expression. Through integrative analysis of genome-wide AR occupancy and androgen-regulated gene expression, here we report AR as a globally acting transcriptional repressor. This repression is mediated by androgen-responsive elements (ARE) and dictated by Polycomb group protein EZH2 and repressive chromatin remodeling. In embryonic stem cells, AR-repressed genes are occupied by EZH2 and harbor bivalent H3K4me3 and H3K27me3 modifications that are characteristic of differentiation regulators, the silencing of which maintains the undifferentiated state. Concordantly, these genes are silenced in castration-resistant prostate cancer rendering a stem cell-like lack of differentiation and tumor progression. Collectively, our data reveal an unexpected role of AR as a transcriptional repressor inhibiting non-prostatic differentiation and, upon excessive signaling, resulting in cancerous dedifferentiation.
| S-EPMC3266039 | biostudies-literature