Transcriptional responses of human melanoma cells to EZH2 inhibition
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PROVIDER: PRJNA589591 | ENA |
REPOSITORIES: ENA
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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:Transcriptional responses of melanoma cells to BRAF inhibition
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Project description:Uveal melanoma cells are resistant to EZH2 inhibition regardless of BAP1 status
2016-06-06 | GSE79905 | GEO
Project description:To explore the anticancer mechanism of ZLD1039, RNA-seq was performed to identify global changes in gene expression in tumors treated with ZLD1039 (100 mg/kg) compared with that in vehicle-treated controls in the A375 xenograft model. The incidence and mortality rate of malignant melanoma are increasing worldwide. Metastasis limits the efficacy of current melanoma therapies and leads to poor prognosis for patients. EZH2 is an epigenetic regulator that promotes the proliferation, metastasis, and drug resistance of tumor cells by regulating transcriptional activity. EZH2 inhibitors could be effective in melanoma therapies. Herein, we aimed to investigate whether the pharmacological inhibition of EZH2 by ZLD1039, a potent and selective S-adenosyl-l-methionine-EZH2 inhibitor, suppresses tumor growth and pulmonary metastasis in melanoma cells. Results showed that ZLD1039 selectively reduced H3K27 methylation in melanoma cells by inhibiting EZH2 methyltransferase activity. Additionally, ZLD1039 exerted excellent antiproliferative effects on melanoma cells in 2D and 3D culture systems. Administration of ZLD1039 (100 mg/kg) by oral gavage caused antitumor effects in the A375 subcutaneous xenograft mouse model. RNA sequencing and GSEA analysis revealed that the ZLD1039-treated tumors exhibited changes in the gene sets enriched for “Cell Cycle” and “Oxidative Phosphorylation”, whereas the “ECM receptor interaction” gene set had a negative enrichment score. Mechanistically, ZLD1039 induced G0/G1 phase arrest by upregulating p16 and p27 and inhibiting the functions of the cyclin D1/CDK6 and cyclin E/CDK2 complex. Moreover, ZLD1039 induced apoptosis in melanoma cells via the mitochondrial reactive oxygen species apoptotic pathway, consistent with the changes in transcriptional signatures. ZLD1039 also exhibited excellent antimetastatic effects on melanoma cells in vitro and in vivo. Our data highlight that ZLD1039 may be effective against melanoma growth and pulmonary metastasis and thus could serve as a therapeutic agent for melanoma.
2025-09-01 | GSE214200 | GEO
Project description:Human melanomas frequently harbor amplifications of EZH2. However, the oncogenic contribution of this methyltransferase to melanoma formation has remained elusive. Taking advantage of murine melanoma models, we now show that EZH2 drives tumorigenesis from benign BrafV600E or NrasQ61K-expressing melanocytes. EZH2 oncogenicity results from silencing of genes relevant for the integrity of the primary cilium, a signaling organelle projecting from the surface of vertebrate cells. Consequently, gain of EZH2 function promotes loss of primary cilia in benign melanocytic lesions. In contrast, blockade of EZH2 activity evokes ciliogenesis and cilia-dependent growth inhibition in malignant melanoma. Finally, we demonstrate that loss of cilia enhances pro-tumorigenic WNT/β-catenin signaling and is itself sufficient to drive metastatic melanoma in benign cells. Thus, primary cilia deconstruction is a key process in EZH2-driven melanomagenesis.
2019-04-04 | GSE112677 | GEO
Project description:EZH2 gain-of-function mutations distort H3K27me3 landscapes and transform transcriptional responses to PRC2 inhibition.
| PRJNA905334 | ENA
Project description:Unleashing the immune anti-tumor response through immune checkpoint blockade (ICB) has been successful in treating many solid-tumor malignancies, including metastatic melanoma. When successful, the ICB response can be potent; however, half of patients fail to respond. ICB responsiveness is impacted by the harsh solid tumor microenvironment (TME), which is characterized by metabolic stress. The TME impacts tumor antigenicity, with ICB-responsive melanomas exhibiting increased major histocompatibility complex class I (MHC-I) expression. Further investigation of tumor immunogenicity in the context of the TME may improve cellular therapies. Here, we define and characterize an epigenetic mechanism regulating melanoma antigen presentation driven by prolonged metabolic stress. Murine and human melanoma cell lines were cultured under prolonged metabolic stress, forcing cells to adapt to the absence of glucose. Melanoma cells adapted to the absence of glucose have IFN-gamma-independent increases in MHC-I and an increased sensitivity to T cell-mediated killing. Proteomic analysis revealed dysregulation of histone epigenetic modifiers under prolonged metabolic stress, specifically loss of histone methyltransferase EZH2 (Enhancer of Zeste Homolog 2). EZH2 directly silences gene transcription via catalyzing H3K27me3. Following metabolic adaptation, ChIP-sequencing and ChIP-PCR revealed H3K27me3 loss at genes specific to MHC-I antigen presentation. Prolonged metabolic stress in melanoma cells blunt EZH2 levels and H3K27me3 levels at promoters of genes regulating MHC-I presentation, resulting in elevated MHC-I antigenicity and increased CD8+ T cell killing. This demonstrates potential for EZH2 abundance and mutational status as a prognostic indicators of ICB-responsiveness in metastatic melanoma and supports EZH2 inhibition as adjuvant for immunotherapies
2024-08-13 | MSV000095589 | MassIVE
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:Unveiling the molecular mechanisms of tissue remodelling following injury is imperative to elucidate its regenerative capacity and aberrant repair in disease. Using different omics approaches, we identified enhancer of zester homolog 2 (EZH2) as a key regulator that initiates a fibrotic cascade in injured lung epithelium. Epithelial-injury-driven enrichment of nuclear transforming growth factor-b-activated kinase 1 (TAK1) mediates EZH2 phosphorylation to facilitate the release of EZH2 from polycomb repressive complex 2 (PRC2). This process leads to the establishment of a fibrotic transcriptional complex of EZH2, RNA-polymerase II (POL2) and nuclear actin, which orchestrates aberrant epithelial lung repair programs. The liberation of EZH2 from PRC2 is accompanied by an EZH2-EZH1 switch to preserve silencing at non-target genes. Loss of epithelial TAK1, EZH2 or blocking nuclear actin influx attenuates the fibrotic cascade and restores respiratory homeostasis. Accordingly, EZH2 inhibition significantly improves outcomes in a pulmonary fibrosis mouse model. Our results reveal an important non-canonical function of EZH2, paving the way for new therapeutic interventions in fibrotic lung diseases.
2021-04-27 | MSV000087321 | MassIVE
Project description:EZH2 gain-of-function mutations distort H3K27me3 landscapes and transform transcriptional responses to PRC2 inhibition [RNA-seq]
| PRJNA905335 | ENA