Activation and repression by oncogenic Myc shapes tumour-specific gene expression profiles
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA190879 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR1204520.fastq.gz | Fastqsanger.gz | |||
| SRR1204530.fastq.gz | Fastqsanger.gz | |||
| SRR1204540.fastq.gz | Fastqsanger.gz | |||
| SRR1204550.fastq.gz | Fastqsanger.gz | |||
| SRR1204560.fastq.gz | Fastqsanger.gz |
Items per page: 5 1 - 5 of 70 |
Similar Datasets
Project description:In mammalian cells, the Myc oncoprotein binds to thousands of promoters. During mitogenic stimulation of primary lymphocytes, Myc promotes an increase in expression of virtually all genes. In contrast, Myc-driven tumour cells differ from normal cells in expression of specific sets of up- and downregulated genes that have significant prognostic value. To understand this discrepancy, we studied the consequences of inducible expression and depletion of Myc in human cells and murine tumour models. Changes in Myc levels activate and repress specific sets of direct target genes that are characteristic of Myc-transformed tumour cells. Three factors account for this specificity: First, the magnitude of response parallels the change in occupancy by Myc at each promoter. Functionally distinct classes of target genes differ in the E-box sequence bound by Myc, arguing that different cellular responses to physiological and oncogenic Myc levels are controlled by promoter affinity. Secondly, Myc both positively and negatively affects transcription initiation independent of its effect on transcriptional elongation. Third, complex formation with Miz1 mediates repression of multiple target genes by Myc and the ratio of Myc and Miz1 bound to each promoter correlates with the direction of response. Myc, Miz1 and RNA polymerase II ChIPseq as well as RNAseq experiments in two human cancer cell lines and murine carcinoma cells as well as fibroblasts from Miz1M-bM-^HM-^FPOZ mice. All sequencing experiment were performed on an Illumina Genome Analyzer IIx.
2014-07-10 | E-GEOD-44672 | biostudies-arrayexpress
Project description:In mammalian cells, the Myc oncoprotein binds to thousands of promoters. During mitogenic stimulation of primary lymphocytes, Myc promotes an increase in expression of virtually all genes. In contrast, Myc-driven tumour cells differ from normal cells in expression of specific sets of up- and downregulated genes that have significant prognostic value. To understand this discrepancy, we studied the consequences of inducible expression and depletion of Myc in human cells and murine tumour models. Changes in Myc levels activate and repress specific sets of direct target genes that are characteristic of Myc-transformed tumour cells. Three factors account for this specificity: First, the magnitude of response parallels the change in occupancy by Myc at each promoter. Functionally distinct classes of target genes differ in the E-box sequence bound by Myc, arguing that different cellular responses to physiological and oncogenic Myc levels are controlled by promoter affinity. Secondly, Myc both positively and negatively affects transcription initiation independent of its effect on transcriptional elongation. Third, complex formation with Miz1 mediates repression of multiple target genes by Myc and the ratio of Myc and Miz1 bound to each promoter correlates with the direction of response.
2014-07-10 | GSE44672 | GEO
Project description:Diffuse midline glioma (DMG) is a fatal childhood brain tumour characterised primarily by mutant histone H3 (H3K27M). H3K27M causes a global reduction in Polycomb Repressive Complex 2 (PRC2)-mediated H3K27me3 by inhibiting PRC2 enzymatic activity. Paradoxically, PRC2 is essential in DMG tumour cells where residual complex activity is required for oncogenic gene repression, although the molecular mechanisms acting downstream of PRC2 in this context are poorly understood. Here, we’ve discovered this oncogenic gene repression is mediated by specific canonical PRC1 (cPRC1) formations. By combining CRISPR screening, biochemical and chromatin mapping approaches with functional perturbations we show that cPRC1 complexes containing CBX4 and PCGF4 drive oncogenic gene repression downstream of H3K27me3 in DMG cells. Remarkably, the altered H3K27me3 modification landscape characteristic of these tumours rewires the distribution of cPRC1 complexes on chromatin. CBX4 and PCGF4 containing cPRC1 accumulate at sites of H3K27me3 while other cPRC1 formations are displaced. Despite accounting for <5% of cPRC1 complexes in DMG, CBX4/PCGF4-containing complexes predominate as gene repressors. Our findings link the altered distribution of H3K27me3 with imbalanced cPRC1 function, promoting oncogenic gene repression in DMG cells, revealing new disease mechanisms and highlighting potential therapeutic opportunities in this incurable childhood brain tumour.
2025-06-24 | PXD058532 | Pride
Project description:Summary Diffuse midline glioma (DMG) is a fatal childhood brain tumour characterised primarily by mutant histone H3 (H3K27M). H3K27M causes a global reduction in Polycomb Repressive Complex 2 (PRC2)-mediated H3K27me3 by inhibiting PRC2 enzymatic activity. Paradoxically, PRC2 is essential in DMG tumour cells where residual complex activity is required for oncogenic gene repression, although the molecular mechanisms acting downstream of PRC2 in this context are poorly understood. Here, we’ve discovered this oncogenic gene repression is mediated by specific canonical PRC1 (cPRC1) formations. By combining CRISPR screening, biochemical and chromatin mapping approaches with functional perturbations we show that cPRC1 complexes containing CBX4 and PCGF4 drive oncogenic gene repression downstream of H3K27me3 in DMG cells. Remarkably, the altered H3K27me3 modification landscape characteristic of these tumours rewires the distribution of cPRC1 complexes on chromatin. CBX4 and PCGF4 containing cPRC1 accumulate at sites of H3K27me3 while other cPRC1 formations are displaced. Despite accounting for <5% of cPRC1 complexes in DMG, CBX4/PCGF4-containing complexes predominate as gene repressors. Our findings link the altered distribution of H3K27me3 with imbalanced cPRC1 function, promoting oncogenic gene repression in DMG cells, revealing new disease mechanisms and highlighting potential therapeutic opportunities in this incurable childhood brain tumour.
2025-06-24 | PXD047451 | Pride
Project description:Diffuse midline glioma (DMG) is a fatal childhood brain tumour characterised primarily by mutant histone H3 (H3K27M). H3K27M causes a global reduction in Polycomb Repressive Complex 2 (PRC2)-mediated H3K27me3 by inhibiting the enzymatic activity of the complex. Paradoxically, PRC2 histone methyltransferase activity is essential in for oncogenic gene repression in DMG tumour cells though downstream molecular mechanisms that are poorly understood. Here, we discover that this oncogenic gene repression is mediated by specific canonical PRC1 (cPRC1) formations containing CBX4. By combining CRISPR screening, biochemical and chromatin mapping approaches with functional perturbations we show that cPRC1 complexes containing CBX4-cPRC1 is co-opted to drive repression downstream of H3K27me3 in DMG cells. Remarkably, the altered H3K27me3 landscape characteristic of H3K27M-mutant DMG rewires the distribution of distinct cPRC1 complexes such that CBX4-cPRC1 accumulates at sites of H3K27me3 while other cPRC1 formations are reduced. Despite CBX4-cPRC1 accounting for less than 5% all cPRC1 H3K27M-mutant DMG, it acts as the predominant repressor of (Polycomb target) neural differentiation genes in this setting. Our findings link the altered distribution of H3K27me3 with imbalances of CBX-cPRC1 functions and consequent oncogenic gene repression, revealing new disease mechanisms and potential therapeutic opportunities in this incurable childhood brain tumour.
2025-06-24 | PXD047401 | Pride
Project description:MYC is an oncogenic driver that regulates transcriptional activation and repression, yet molecular mechanisms of MYC transformation remain unclear. We demonstrate that MYC interacts with the G9a H3K9-methyltransferase complex to control transcriptional repression. Inhibiting G9a hinders MYC chromatin binding at MYC-repressed genes and de-represses gene expression to antagonize cellular transformation. By identifying the MYC Box II region as essential for MYC-G9a interaction, a long-standing missing link between MYC transformation and gene repression is unveiled. In breast cancer, anti-proliferative sensitivity to G9a pharmacological inhibition associates with MYC sensitivity and the basal subtype. Inhibiting G9a in vivo suppresses MYC-dependent basal breast tumor growth. Our findings reveal G9a as an epigenetic regulator of MYC-mediated transcriptional repression and a therapeutic vulnerability in MYC-driven cancers.
2018-10-08 | GSE115024 | GEO
Project description:The potent MYC oncoprotein is deregulated in many human cancers, including breast carcinoma, and is associated with aggressive disease. To understand the mechanisms and vulnerabilities of MYC-driven breast cancer, we have generated an in vivo model that mimics human disease in response to MYC deregulation. MCF10A cells ectopically expressing a common breast cancer mutation in the PI3 kinase pathway (PIK3CAH1047R) lead to the development of organized acinar structures in mice. However, expressing both PIK3CAH1047R and deregulated-MYC lead to the development of invasive ductal carcinoma, thus creating a model in which a MYC-dependent normal-to-tumour switch occurs in vivo. These MYC-driven tumours exhibit classic hallmarks of human breast cancer at both the pathological and molecular levels. Moreover, tumour growth is dependent upon sustained deregulated MYC expression, further demonstrating addiction to this potent oncogene and regulator of gene transcription. We therefore provide a MYC-dependent model of breast cancer which can be assayed for in vivo tumour initiation, proliferation, and transformation from normal breast acini into invasive breast carcinoma. Taken together, we anticipate that this novel MYC-driven transformation model will be a useful research tool to both better understand MYC’s oncogenic function and identify therapeutic vulnerabilities.
2019-07-25 | GSE130513 | GEO
Project description:In mammalian cells, the MYC oncoprotein binds to thousands of promoters. During mitogenic stimulation of primary lymphocytes, MYC promotes an increase in the expression of virtually all genes. In contrast, MYC-driven tumour cells differ from normal cells in the expression of specific sets of up- and downregulated genes that have considerable prognostic value. To understand this discrepancy, we studied the consequences of inducible expression and depletion of MYC in human cells and murine tumour models. Changes in MYC levels activate and repress specific sets of direct target genes that are characteristic of MYC-transformed tumour cells. Three factors account for this specificity. First, the magnitude of response parallels the change in occupancy by MYC at each promoter. Functionally distinct classes of target genes differ in the E-box sequence bound by MYC, suggesting that different cellular responses to physiological and oncogenic MYC levels are controlled by promoter affinity. Second, MYC both positively and negatively affects transcription initiation independent of its effect on transcriptional elongation. Third, complex formation with MIZ1 (also known as ZBTB17) mediates repression of multiple target genes by MYC and the ratio of MYC and MIZ1 bound to each promoter correlates with the direction of response.
| S-EPMC6879323 | biostudies-literature
Project description:MYC is a master regulator of transcriptional activation and repression that mediates diverse physiological and disease functions, including hematopoiesis, aging, and oncogenesis, yet its essential co-regulators remain unclear. We demonstrate that MYC interacts with and regulates the G9a H3K9 methyltransferase complex to control transcriptional repression in cancer. Inhibiting G9a hinders MYC binding, shifts repressive epigenetic locales to an active state, and de-represses gene expression to antagonize MYC-dependent cellular processes. MYC requires MYC Box II region for its interaction with G9a, providing a mechanism for this region essential for transcriptional repression. In treatment models of MYC-dependent basal breast cancer, genetically inhibiting G9a decreases tumour growth. Anti-proliferative sensitivity to G9a small molecule inhibitors correlates with sensitivity to MYC knockdown and associates with the basal subtype. Our findings illustrate an epigenetic model of MYC-mediated transcriptional repression in driving oncogenesis and establishes G9a as a therapeutic vulnerability in MYC-driven cancers.
2018-10-08 | GSE100335 | GEO
Project description:MYC genes have both essential roles during normal development and exert oncogenic functions during tumorigenesis. Expression of a dominant-negative allele of MYC, termed OmoMYC, can induce rapid tumor regression in mouse models with little toxicity for normal tissues. How OmoMYC discriminates between physiological and oncogenic functions of MYC is unclear. We have solved the crystal structure of OmoMYC and show that it forms a stable homodimer and as such recognizes DNA in the same manner as the MYC/MAX heterodimer. OmoMYC attenuates both MYC-dependent activation and repression by competing with MYC/MAX for binding to chromatin, effectively lowering MYC/MAX occupancy at its cognate binding sites. OmoMYC causes the largest decreases in promoter occupancy and changes in expression on genes that are invaded by oncogenic MYC levels. A signature of OmoMYC-regulated genes defines subgroups with high MYC levels in multiple tumor entities and identifies novel targets for the eradication of MYC-driven tumors.
2016-10-18 | GSE77328 | GEO