Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA266893 | ENA |
REPOSITORIES: ENA
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Project description:Increased activity of the epigenetic modifier EZH2 has been associated with different cancers. However, evidence for a functional role of EZH2 in tumourigenesis in vivo remains poor, in particular in metastasising solid cancers. Here we reveal central roles of EZH2 in promoting growth and metastasis of cutaneous melanoma. In a melanoma mouse model, conditional Ezh2 ablation as much as treatment with the preclinical Ezh2 inhibitor GSK503 stabilises the disease through inhibition of growth and virtually abolishes metastases formation without affecting normal melanocyte biology. Comparably, in human melanoma cells, EZH2 inactivation impairs proliferation and invasiveness, accompanied by re-expression of tumour suppressors connected to increased patient survival. These EZH2 target genes suppress melanoma growth and prevent EMT / metastasis in vivo revealing the dual function of EZH2 in promoting tumour progression. Thus, EZH2-mediated epigenetic repression is highly relevant especially during advanced melanomagenesis, which makes EZH2 a promising target for novel melanoma therapies.
2014-11-12 | GSE63165 | GEO
Project description:Dissection of melanoma heterogeneity through gene expression profiling has led to the identification of two major phenotypes, conventionally defined as “MITF high / proliferative” and “AXL high / invasive”. Tumors or single melanoma cells characterized by a predominant AXL-related gene program show enhanced expression of sets of genes involved in motility, invasion and regulation of epithelial-mesenchymal transition (EMT), while these genes are downregulated in tumors or cells with a predominant MITF-related gene program. The activation of the AXLhi/MITFlo invasive gene program in melanoma is characterized by aberrant expression of transcription factors (TFs) involved in the embryonic EMT process. Additional master genes involved in promoting melanoma growth and invasive state have been identified within the family of epigenetic regulators. Two of these genes, RNF2 and EZH2, components of the polycomb repressive complexes 1 and 2, act by epigenetically silencing tumor suppressors that in turn regulate the invasive and EMT-like phenotype of melanoma cells. Additional master genes involved in promoting melanoma growth and invasive state have been identified within the family of epigenetic regulators. Two of these genes, RNF2 and EZH2, components of the polycomb repressive complexes 1 and 2, act by epigenetically silencing tumor suppressors that in turn regulate the invasive and EMT-like phenotype of melanoma cells. Here we provide evidence for a new actionable pathway that controls melanoma EMT-like/invasive phenotype. We show that in MITFlo melanomas, the TF NFATc2 controls the EMT-like transcriptional program, the invasive ability of neoplastic cells, as well as in-vitro and in-vivo growth, through a pathway that functionally links c-myc to FOXM1 and EZH2. Targeting of NFATc2, FOXM1 or EZH2 inhibited melanoma migratory and invasive activity. Moreover, pharmacological co-targeting of NFATc2 and EZH2 promoted apoptosis of BRAF-mutant melanomas with intrinsic resistance to BRAF inhibition.
2019-02-06 | GSE101323 | GEO
Project description:Normal cell growth is characterized by a regulated epigenetic program that drives cellular activities such as gene transcription, DNA replication and DNA damage repair. Perturbation of this epigenetic program can lead to events such as mis-regulation of gene transcription and diseases such as cancer. To begin to understand the epigenetic program correlated to the development of melanoma, we performed a quantitative mass spectrometric analysis of histone posttranslational modifications mis-regulated in melanoma cell culture. Aggressive melanoma cells were found to have elevated histone H3 lysine 27 trimethylation (H3K27me3) as well as over-expressed methyltransferase EZH2 that adds the specific modification. The altered epigenetic program that led to elevated H3K27me3 in melanoma cell culture was found to directly silence transcription of the tumor suppressor gene RUNX3. The elevated level of H3K27me3 and silencing of RUNX3 transcription was also validated in advanced stage human melanoma tissues. The study presented underscores the utility of using high resolution mass spectrometry to identify mis-regulated epigenetic programs in diseases such as cancer, which could ultimately lead to the identification of biological markers for diagnostic and prognostic applications.
2015-12-02 | PXD002471 | Pride
Project description:Normal cell growth is characterized by a regulated epigenetic program that drives cellular activities such as gene transcription, DNA replication and DNA damage repair. Perturbation of this epigenetic program can lead to events such as mis-regulation of gene transcription and diseases such as cancer. To begin to understand the epigenetic program correlated to the development of melanoma, we performed a quantitative mass spectrometric analysis of histone posttranslational modifications mis-regulated in melanoma cell culture. Aggressive melanoma cells were found to have elevated histone H3 lysine 27 trimethylation (H3K27me3) as well as over-expressed methyltransferase EZH2 that adds the specific modification. The altered epigenetic program that led to elevated H3K27me3 in melanoma cell culture was found to directly silence transcription of the tumor suppressor gene RUNX3. The elevated level of H3K27me3 and silencing of RUNX3 transcription was also validated in advanced stage human melanoma tissues. The study presented underscores the utility of using high resolution mass spectrometry to identify mis-regulated epigenetic programs in diseases such as cancer, which could ultimately lead to the identification of biological markers for diagnostic and prognostic applications.
2016-07-22 | MSV000079979 | MassIVE
Project description:Gene expression profiling has uncovered the transcription factor Sox4 with up-regulated activity during TGFβ-induced EMT in normal and cancerous breast epithelial cells. Sox4 is indispensable for EMT and cell survival in vitro and for primary tumor growth and metastasis in vivo. Among several EMT-relevant genes, Sox4 directly regulates the expression of Ezh2, encoding the Polycomb group histone methyltransferase that trimethylates histone 3 lysine 27 (H3K27me3) for gene repression. Ablation of Ezh2 expression prevents EMT, while forced expression of Ezh2 restores EMT in Sox4-deficient cells. Ezh2-mediated H3K27me3 marks associate with key EMT genes, representing an epigenetic EMT signature that predicts patient survival. Our results identify Sox4 as a master regulator of EMT by governing the expression of the epigenetic modifier Ezh2. Our Dataset comprises of 12 ChIP-seq samples using chromatin from NMuMG cells which was immunoprecipitated using H3K27me3-specific antibody during TGFβ-induced EMT (2ng/ml) at 6 different stages (day 0, 1, 4, 7, 10, 20).
2013-06-20 | E-GEOD-45579 | biostudies-arrayexpress
Project description:The epigenetic modifier EZH2 is part of the polycomb repressive complex that suppresses gene expression via histone methylation. Activating mutations in EZH2 are found in a subset of melanoma that contributes to disease progression by inactivating tumor suppressor genes. In this study we have targeted EZH2 with a specific inhibitor (GSK126) or depleted EZH2 protein by stable shRNA knockdown. We show that inhibition of EZH2 has potent effects on the growth of both wild-type and EZH2 mutant human melanoma in vitro particularly in cell lines harboring the EZH2Y646 activating mutation. This was associated with cell cycle arrest, reduced proliferative capacity in both 2D and 3D culture systems, and induction of apoptosis. The latter was caspase independent and mediated by the release of apoptosis inducing factor (AIFM1) from mitochondria. Gene expression arrays showed that several well characterized tumor suppressor genes were reactivated by EZH2 inhibition. This included activating transcription factor 3 (ATF3) that was validated as an EZH2 target gene by ChIP-qPCR. These results emphasize a critical role for EZH2 in the proliferation and viability of melanoma and highlight the potential for targeted therapy against EZH2 in treatment of patients with melanoma. Tiffen JC, Gunatilake D, Gallagher SJ, Gowrishankar K, Heinemann A, Cullinane C, et al. Targeting activating mutations of EZH2 leads to potent cell growth inhibition in human melanoma by derepression of tumor suppressor genes. Oncotarget 2015;12:12
2019-11-15 | GSE140394 | GEO
Project description:Metastasis is the primary cause of death of cancer patients. Dissecting mechanisms governing metastatic spread may uncover important tumor biology and/or yield promising therapeutic insights. Here we investigated the role of circular RNAs (circRNA) in metastasis, using melanoma as a model aggressive tumor. We identified silencing of Cerebellar Degeneration Related 1 (CDR1as), a regulator of the microRNA miR-7, as a hallmark of melanoma progression. We find that CDR1as depletion results from epigenetic silencing of its originating lincRNA, and promotes invasion in vitro and metastasis in vivo, through a miR-7-independent, IGF2BP3-mediated mechanism. Moreover, CDR1as levels identify cellular states associated with distinct therapeutic responses. Our study reveals functional, prognostic and predictive roles for CDR1as and expose circRNAs as key players in metastasis.
2020-01-13 | GSE138710 | GEO
Project description:Metastasis is the primary cause of death of cancer patients. Dissecting mechanisms governing metastatic spread may uncover important tumor biology and/or yield promising therapeutic insights. Here we investigated the role of circular RNAs (circRNA) in metastasis, using melanoma as a model aggressive tumor. We identified silencing of Cerebellar Degeneration Related 1 (CDR1as), a regulator of the microRNA miR-7, as a hallmark of melanoma progression. We find that CDR1as depletion results from epigenetic silencing of its originating lincRNA, and promotes invasion in vitro and metastasis in vivo, through a miR-7-independent, IGF2BP3-mediated mechanism. Moreover, CDR1as levels identify cellular states associated with distinct therapeutic responses. Our study reveals functional, prognostic and predictive roles for CDR1as and expose circRNAs as key players in metastasis.
2020-01-13 | GSE138412 | GEO
Project description:A cytosolic role for EZH2 in regulating cell signaling via interaction with the VAV family of proteins has been reported by us previously. However, it is unclear whether EZH2 interactions with VAV are critical for tumorigenesis. Here, we show that cytosolic EZH2 exhibits greater transforming/metastatic capacity than wild-type EZH2 and that targeted disruption of the EZH2-VAV interaction abolishes EZH2-promoted tumorigenesis. We also found that interaction of cytosolic EZH2 with VAV is critical for EZH2-mediated talin methylation and subsequent STAT3 activation. Both cytosolic EZH2 and a methyl-mimicking talin mutant substantially promoted STAT3 activation and tumor growth. We therefore propose that the VAV-dependent cytosolic function of EZH2 may be a critical step in the initiation of cellular transformation, preceding the well-established function of EZH2 in epigenetic silencing of tumor suppressors. Thus, disrupting EZH2-VAV interaction could be an alternative intervention strategy for treatment of cancers associated with EZH2 overexpression.
2017-10-04 | E-MTAB-3599 | biostudies-arrayexpress
Project description:Genomic sequencing of hepatocellular carcinoma (HCC) uncovers a paucity of actionable mutations, underscoring the necessity to exploit epigenetic vulnerabilities for therapeutics. In HCC, EZH2-mediated H3K27me3 represents a major oncogenic chromatin modification, but how it modulates the therapeutic vulnerability of signaling pathways remains unknown. Here, we identified that EZH2 maintains H3K27 methylome through epigenetic silencing of specific gene sets. ChIP-seq revealed enrichment of EZH2/H3K27me3 at silenced loci in HBx-transgenic (TG) mouse-derived HCCs, including tumor suppressors whose down-regulation significantly correlated with EZH2 overexpression and poor survival of HCC patients. Defining the aberrant chromatin landscape of HCC sheds light into the mechanistic basis of effective EZH2-targeted inhibition.
2018-07-02 | GSE113326 | GEO