Stabilization of the Max homodimer with a small molecule attenuates Myc-driven transcription
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA517722 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The transcription factor Max is a basic helix-loop-helix leucine zipper (bHLHLZ) protein that forms homodimers or interacts with other bHLHLZ proteins, including Myc and Mxd proteins. Among this dynamic network of interactions, the Myc/Max heterodimer has crucial roles in regulating normal cellular processes, but its transcriptional activity is deregulated in a majority of human cancers. Despite this significance, the arsenal of high-quality chemical probes to interrogate these proteins remains limited. We utilized small molecule microarrays (SMMs) to identify compounds that bind Max in a mechanistically unbiased manner. We discovered the asymmetric polycyclic lactam, KI-MS2-008, which stabilizes the Max homodimer while reducing Myc protein and Myc-regulated transcript levels. KI-MS2-008 also decreases viable cancer cell growth in a Myc-dependent manner and suppresses tumor growth in vivo. This approach demonstrates the feasibility of modulating Max with small molecules and supports altering Max dimerization as an alternative approach to targeting Myc.
2019-03-14 | GSE125863 | 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
Project description:The Myc/Max heterodimer has crucial roles in normal cellular processes such as cell proliferation, metabolism, apoptosis, and differentiation, but its activity is often deregulated in a majority of human cancers. In an effort to explore alternative modes of Myc perturbation, we identified KI-MS2-008 as a small molecule that binds Max and modulates Myc-driven transcription, and in some cellular contexts, KI-MS2-008 treatment leads to a decrease in c-Myc protein levels. As the Myc/Max heterodimer controls many cellular processes, we expected that treatment with this small molecule would cause changes in the transcriptome. We found that treatment with 10 µM KI-MS2-008 resulted in global alterations in the transcriptome, mimicking direct Myc inactivation with doxycycline in P493-6, a B cell line with a Tet-Off system for c-Myc expression. We also discovered enrichment of various Myc target gene sets in the genes downregulated in response to KI-MS2-008 treatment in P493-6 cells. This trend was also observed in ST486 cells, but not in P3HR1 cells, which were chosen as non-engineered B cell lines that were sensitive and insensitive, respectively, toward KI-MS2-008 in cell viability assays.
2019-03-14 | GSE107222 | GEO
Project description:MYC genes are frequently amplified and correlate with poor prognosis in MB. BET bromodomains recognize acetylated lysine residues and often promote and maintain MYC transcription. Certain cyclin-dependent kinases (CDKs) are further known to support MYC stabilization in tumor cells. In this report, MB cells were suppressed by combined targeting of MYC expression and MYC stabilization using BET bromodomain inhibition and CDK2 inhibition, respectively. Such combination treatment worked synergistically and caused cell cycle arrest as well as massive apoptosis. Immediate transcriptional changes from this combined MYC blockade were found using RNA-Seq profiling and showed remarkable similarities to changes in MYC target gene expression when MYCN was turned off with doxycycline in our MYCN-inducible animal model for Group 3 MB. In addition, the combination treatment significantly prolonged survival as compared to single agent therapy in orthotopically transplanted human Group 3 MB with MYC amplifications. Our data suggests that dual inhibition of CDK2 and BET bromodomains can be a novel treatment approach for suppressing MYC-driven cancer.
2018-06-06 | GSE107405 | GEO
Project description:The goal of this study was to genomic occupancy of MAX, MNT, MYC and E2F1 in B cells in the presence and absence of transcription factor MAX Although MAX is regarded as an obligate dimerization partner for MYC, its function in normal development and neoplasia is poorly defined. We show that B-cell specific deletion of Max has a modest effect on B-cell development but completely abrogates E -Myc driven lymphomagenesis. While Max loss only affects a few hundred genes in normal B cells, it leads to the global downregulation of Myc-activated genes in premalignant E -Myc cells. We show that the balance between MYC-MAX and MNT-MAX interactions in B cells shifts in pre-malignant B cells towards a MYC driven transcriptional program. Moreover, we find that MAX loss leads to a significant reduction in MYC protein levels and downregulation of direct transcriptional targets, including regulators of MYC stability. This phenomenon is also observed in multiple cell lines treated with MYC-MAX dimerization inhibitors. Our work uncovers a layer of Myc autoregulation critical for lymphomagenesis yet partly dispensable for normal development.
2019-06-20 | GSE132967 | GEO
Project description:Baricitinib attenuates the proinflammatory phase1 of COVID-19 driven by lung-infiltrating monocytes
| PRJNA773942 | ENA
Project description:To identify proteomic signatures associated with hepatocellular carcinoma driven by MYC overexpression, proteomics was performed on the LAP-tTA/tetO-MYC mouse conditional liver cancer model. Upon MYC activation, mice form liver cancer. Differential proteomics was performed in "MYC on" (MYC-HCC) mouse liver tumors versus mouse control normal liver tissue (where MYC was not overexpressed to drive tumorigenesis -- "MYC off").
2022-10-12 | PXD031478 | Pride
Project description:Deregulated expression of MYC family oncogenes occurs frequently in human cancer and is often associated with aggressive disease and poor prognosis. While MYC is a highly warranted target, it has been considered “undruggable”, and no specific anti-MYC drugs are available in the clinic. We recently identified molecules named MYCMIs that inhibit the interaction between MYC and its essential partner MAX. Here we show that one of these, MYCMI-7, efficiently and selectively inhibits MYC:MAX and MYCN:MAX interactions in cells, binds directly to recombinant MYC and reduces MYC-driven transcription. In addition, MYCMI-7 induces degradation of MYC and MYCN proteins. MYCMI-7 potently induces growth arrest/apoptosis in tumor cells in a MYC/MYCN- dependent manner and downregulates the MYC pathway on a global level as determined by RNA-seq. Sensitivity to MYCMI-7 correlates with MYC expression in a panel of 60 tumor cell lines and MYCMI-7 shows high efficacy towards a collection of patient- derived primary glioblastoma and acute myeloid leukemia (AML) ex vivo cultures. Importantly, a variety of normal cells become G1 arrested without signs of apoptosis upon MYCMI-7 treatment. Finally, in mouse tumor models of MYC-driven AML, breast cancer and MYCN-amplified neuroblastoma, treatment with MYCMI-7 downregulates MYC/MYCN, inhibits tumor growth and prolongs survival through apoptosis with little side effects. In conclusion, MYCMI-7 is a potent and selective MYC inhibitor that is highly relevant for the development into clinically useful drugs for treatment of MYC-driven cancer.
2023-03-08 | GSE197062 | GEO
Project description:The Myc-Max heterodimer is a DNA binding protein that regulates expression of a large number of genes. Genome occupancy of Myc-Max is thought to be driven by E-boxes (CACGTG or variants) to which the heterodimer binds in vitro. By analyzing ChIP-Seq datasets, we demonstrated that the positions occupied by Myc-Max across the human genome correlate with the RNA polymerase II (Pol II) transcription machinery better than with E-boxes. Metagene analyses showed that in promoter regions, Myc was uniformly positioned about 100 bp upstream of essentially all promoter proximal paused polymerases with Max about 10 bp upstream of Myc. We re-evaluated the DNA binding properties of full length Myc-Max proteins using electrophoretic mobility shift assays (EMSA) and protein-binding microarrays (PBM). EMSA results demonstrated Myc-Max heterodimers have high affinity for both E-box containing and non-specific DNA. Quantification of the relative affinities of Myc-Max for all possible 8- mers using PBM assays showed that sequences surrounding core 6-mers significantly affect binding. Comparing to the in vitro sequence preferences, Myc-Max genomic occupancy measured by ChIP-Seq was largely, although not completely, independent of sequence specificity. Our results suggest that the transcription machinery and associated promoter accessibility play an important role in genomic occupancy of Myc.
2014-09-22 | GSE58570 | GEO
Project description:Mutations in splicing factor SF3B1 promote transformation through MYC stabilization
| PRJNA478381 | ENA