Chromosome loop control of oncogenic MYC produces a common vulnerability in diverse cancers
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE92881 | GEO | 2016/12/24
SECONDARY ACCESSION(S): PRJNA358692
REPOSITORIES: GEO
Similar Datasets
Project description:The majority of human cancers become highly dependent on a deregulated MYC oncogene, thus identifying a common mechanism underlying MYC regulation could provide valuable targets for therapy. We show here that diverse tumor-specific super-enhancers acquired throughout the 3Mb MYC insulated neighborhood functionally interact with a single conserved site occupied by CTCF protein in the MYC promoter. CRISPR-mediated deletion analysis shows that this common CTCF site is required for super-enhancer looping to the MYC promoter, high MYC expression and rapid cell proliferation in multiple cancers. Targeted methylation of the MYC enhancer anchor by a dCAS9-DNMT3A-3L fusion protein abrogates CTCF binding with consequent loss of MYC expression, suggesting a common vulnerability and a novel approach for therapeutic targeting of aggressive cancers.
2018-03-20 | GSE112000 | GEO
Project description:The majority of human cancers become highly dependent on a deregulated MYC oncogene, thus identifying a common mechanism underlying MYC regulation could provide valuable targets for therapy. We show here that diverse tumor-specific super-enhancers acquired throughout the 3Mb MYC insulated neighborhood functionally interact with a single conserved site occupied by CTCF protein in the MYC promoter. CRISPR-mediated deletion analysis shows that this common CTCF site is required for super-enhancer looping to the MYC promoter, high MYC expression and rapid cell proliferation in multiple cancers. Targeted methylation of the MYC enhancer anchor by a dCAS9-DNMT3A-3L fusion protein abrogates CTCF binding with consequent loss of MYC expression, suggesting a common vulnerability and a novel approach for therapeutic targeting of aggressive cancers.
2016-12-24 | GSE92880 | GEO
Project description:The majority of human cancers become highly dependent on a deregulated MYC oncogene, thus identifying a common mechanism underlying MYC regulation could provide valuable targets for therapy. We show here that diverse tumor-specific super-enhancers acquired throughout the 3Mb MYC insulated neighborhood functionally interact with a single conserved site occupied by CTCF protein in the MYC promoter. CRISPR-mediated deletion analysis shows that this common CTCF site is required for super-enhancer looping to the MYC promoter, high MYC expression and rapid cell proliferation in multiple cancers. Targeted methylation of the MYC enhancer anchor by a dCAS9-DNMT3A-3L fusion protein abrogates CTCF binding with consequent loss of MYC expression, suggesting a common vulnerability and a novel approach for therapeutic targeting of aggressive cancers.
2016-12-24 | GSE92879 | GEO
Project description:Chromosome loop control of oncogenic MYC produces a common vulnerability in diverse cancers
| PRJNA358692 | ENA
Project description:Chromosome loop control of oncogenic MYC produces a common vulnerability in diverse cancers [HiChIP]
| PRJNA438926 | ENA
Project description:Genome-wide association studies (GWAS) have successfully identified common polymorphisms that are strongly associated with many traits, including cancer. A gene desert located on chromosome 8q24 is associated with multiple cancer types. One of the closest genes is the MYC proto-oncogene. Investigations are now turning toward a mechanistic understanding of these (and other) risk loci. Recent studies demonstrate that the 8q24 loci are enhancers and that they physically interact with MYC. A still unresolved issue is the absence of a consistent association between genotype status at the risk loci and steady-state MYC expression levels in adult human tissues. Clarifying the function of the 8q24 variants and their link to MYC regulation by further in vivo and in vitro functional studies will allow a deeper understanding of the mechanisms underlying human cancer development.
| S-EPMC3092220 | biostudies-literature
Project description:Myc is one of the most commonly deregulated oncogenes in human cancer, yet therapies directly targeting Myc hyperactivation are not presently available in the clinic. The evolutionarily conserved function of Myc in modulating protein synthesis control is critical to the Myc oncogenic program. Indeed, enhancing the protein synthesis capacity of cancer cells directly contributes to their survival, proliferation, and genome instability. Therefore, inhibiting enhanced protein synthesis may represent a highly relevant strategy for the treatment of Myc-dependent human cancers. However, components of the translation machinery that can be exploited as therapeutic targets for Myc-driven cancers remain poorly defined. Here, we uncover a surprising and important functional link between Myc and mammalian target of rapamycin (mTOR)-dependent phosphorylation of eukaryotic translation initiation factor 4E binding protein-1 (4EBP1), a master regulator of protein synthesis control. Using a pharmacogenetic approach, we find that mTOR-dependent phosphorylation of 4EBP1 is required for cancer cell survival in Myc-dependent tumor initiation and maintenance. We further show that a clinical mTOR active site inhibitor, which is capable of blocking mTOR-dependent 4EBP1 phosphorylation, has remarkable therapeutic efficacy in Myc-driven hematological cancers. Additionally, we demonstrate the clinical implications of these results by delineating a significant link between Myc and mTOR-dependent phosphorylation of 4EBP1 and therapeutic response in human lymphomas. Together, these findings reveal that an important mTOR substrate is found hyperactivated downstream of Myc oncogenic activity to promote tumor survival and confers synthetic lethality, thereby revealing a unique therapeutic approach to render Myc druggable in the clinic.
| S-EPMC3718086 | biostudies-other
Project description:c-MYC (MYC) is deregulated in more than 50% of all cancers. While MYC amplification is the most common MYC-deregulating event, many other alterations can increase MYC activity. We thus systematically investigated MYC pathway activity across different tumor types. Using a logistic regression framework, we established tumor type-specific, transcriptomic-based MYC activity scores that can accurately capture MYC activity. We show that MYC activity scores reflect a variety of MYC-regulating mechanisms, including MYCL and/or MYCN amplification, MYC promoter methylation, MYC mRNA expression, lncRNA PVT1 expression, MYC mutations, and viral integrations near the MYC locus. Our MYC activity score incorporates all of these mechanisms, resulting in better prognostic predictions compared with MYC amplification status, MYC promoter methylation, and MYC mRNA expression in several cancer types. In addition, we show that tumor proliferation and immune evasion are likely contributors to this reduction in survival. Finally, we developed a MYC activity signature for liquid tumors in which MYC translocation is commonly observed, suggesting that our approach can be applied to different types of genomic alterations. In conclusion, we developed a MYC activity score that captures MYC pathway activity and is clinically relevant. IMPLICATIONS: By using cancer type-specific MYC activity profiles, we were able to assess MYC activity across many more tumor types than previously investigated. The range of different MYC-related alterations captured by our MYC activity score can be used to facilitate the application of future MYC inhibitors and aid physicians to preselect patients for targeted therapy.
| S-EPMC7925347 | biostudies-literature
Project description:Mutations underlie all cancers, and their identification and study are the foundation of cancer biology. We describe what we believe to be a novel approach to mutagenesis and cancer studies based on the DNA polymerase ε (POLE) ultramutator phenotype recently described in human cancers, in which a single amino acid substitution (most commonly P286R) in the proofreading domain results in error-prone DNA replication. We engineered a conditional PoleP286R allele in mice. PoleP286R/+ embryonic fibroblasts exhibited a striking mutator phenotype and immortalized more efficiently. PoleP286R/+ mice were born at Mendelian ratios but rapidly developed lethal cancers of diverse lineages, yielding the most cancer-prone monoallelic model described to date, to our knowledge. Comprehensive whole-genome sequencing analyses showed that the cancers were driven by high base substitution rates in the range of human cancers, overcoming a major limitation of previous murine cancer models. These data establish polymerase-mediated ultramutagenesis as an efficient in vivo approach for the generation of diverse animal cancer models that recapitulate the high mutational loads inherent to human cancers.
| S-EPMC6118636 | biostudies-literature
Project description:Chromosome fragmentation (C-Frag) is a newly identified MCD (mitotic cell death), distinct from apoptosis and MC (mitotic catastrophe). As different molecular mechanisms can induce C-Frag, we hypothesize that the general mechanism of its induction is a system response to cellular stress. A clear link between C-Frag and diverse system stresses generated from an array of molecular mechanisms is shown. Centrosome amplification, which is also linked to diverse mechanisms of stress, is shown to occur in association with C-Frag. This led to a new model showing that diverse stresses induce common, MCD. Specifically, different cellular stresses target the integral chromosomal machinery, leading to system instability and triggering of MCD by C-Frag. This model of stress-induced cell death is also applicable to other types of cell death. The current study solves the previously confusing relationship between the diverse molecular mechanisms of chromosome pulverization, suggesting that incomplete C-Frag could serve as the initial event responsible for forms of genome chaos including chromothripsis. In addition, multiple cell death types are shown to coexist with C-Frag and it is more dominant than apoptosis at lower drug concentrations. Together, this study suggests that cell death is a diverse group of highly heterogeneous events that are linked to stress-induced system instability and evolutionary potential.
| S-EPMC3169002 | biostudies-literature