A Functional Role of OLIG2 in Tumor Heterogeneity of MYC-amplified Medulloblastoma
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PROVIDER: PRJNA780565 | ENA |
REPOSITORIES: ENA
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Project description:A Functional Role of OLIG2 in Tumor Heterogeneity of MYC-amplified Medulloblastoma
| PRJNA780320 | ENA
Project description:To study how radiation alters the different types of cells during tumor recurrence in high-risk MYC-amplified MB, we performed scRNA-seq using the 10X Genomics scRNA-seq platform to compare the primary untreated tumors, residual tumors immediately following radiotherapy, and the spontaneously recurrent tumors 7-8 weeks post-irradiation using OLIG2-high MB002 PDX. We found that:1, the variety of cell types demonstrated that the MYC-amplified MB PDX tumors were heterogenous communities, comprising diverse cell types in a broad range differentiation states and developmental trajectories, and included the host-derived cells of the tumor microenvironment; 2, Radiation-induced transient changes in cellular heterogeneity that resolved as tumor recurred; 3, Recurrent tumors showed global changes in gene expression compared to primary tumors
2021-11-20 | GSE188887 | GEO
Project description:The goal of this study was to compare gene expression profiles of MYC-amplified medulloblastoma tumors under three distinct conditions: primary tumors prior to radiation treatment, tumors derived from implanted radio-resistant tumor cells, and spontaneously recurring tumors several weeks post-irradiation. The purpose of this experiment was to identify the moleular pathways that are impacted during radiation and those which contribute to tumor recurrence. Unsupervised hierarchical cluster analysis revealed that the tumors which spontaneously recurred in vivo closely resembled the primary tumors. Tumors from implanted post-radiation neurospheres, however, had markedly different profiles. We identified 44 upregulated and 23 downregulated genes in the spontaneously recurred tumors compared to untreated primary tumors. Furthermore, we identified 817 upregulated and 509 downregulated genes in tumors derived from implanted post-radiation neurospheres compared to untreated primary tumors. Among these genes, 756 (57%) genes were also differentially expressed between tumors derived from implanted post-radiation neurospheres and spontaneously recurrent tumors. The downregulated pathways in tumors derived from implanted post-radiation neurospheres were associated with p53, cell cycle, DNA replication, and DNA damage, and the upregulated genes are involved in metabolic pathways. This study demonstrates that radiation resistant tumor cells exhibit differential gene expression post-irradiation and during tumor recurrence and provides a framework for the study of genetic pathways leading to tumor recurrence post-irradiation.
2021-11-16 | GSE188789 | GEO
Project description:As the most life-threatening subtype of pediatric medulloblastoma (MB), MYC-amplified Group 3 (G3) MB lacks effective and selective therapeutics. We tried to indirectly target MYC (oncogenic driver and cancer-dependent molecule) production via inhibiting translational machinery. Through multiple datasets analyses on components of eIF4F (eukaryotic translation initiation factor 4F) complex, we found that EIF4A1 (major component with RNA helicase activity) has relatively higher expression level and the closest positive correlation with MYC in G3-MB among normal control and other 3 subtypes (e.g., WNT, SHH and G4). Both in vitro and in vivo experiments with MYC-amplified G3-MB cell lines showed effective growth inhibition upon EIF4A1 knockout or inhibitor treatment. Further FACS analysis found decreased cell proliferation and enhanced apoptosis on EIF4A1 inhibitor treatment. To explore the mechanisms of EIF4A1 inhibition on arresting MYC-amplified G3-MB, we performed the whole proteome analyses on corresponding MB cells treated with EIF4A1 inhibitor.
2020-10-15 | PXD022014 | iProX
Project description:MYC is a driver oncogene in many cancers. Inhibition of MYC promises high therapeutic potential, but specific MYC inhibitors remain unavailable for clinical use. Previous studies suggest that MYC amplified Medulloblastoma cells are vulnerable to HDAC inhibition. Using co-immunoprecipitation, mass spectrometry and ChIP-sequencing we show that HDAC2 is a cofactor of MYC in MYC amplified primary medulloblastoma and cell lines. The MYC-HDAC2 complex is bound to genes defining the MYC-dependent transcriptional profile. Class I HDAC inhibition leads to stabilization and reduced DNA binding of MYC protein inducing a down-regulation of MYC activated genes (MAGs) and up-regulation of MYC repressed genes (MRGs). MAGs and MRGs are characterized by opposing biological functions and distinct E-box distribution. We conclude that MYC and HDAC2 (class I) are localized in a complex in MYC amplified medulloblastoma and drive a MYC-specific transcriptional program, which is reversed by the class I HDAC inhibitor entinostat. Thus, the development of HDAC inhibitors for treatment of MYC amplified medulloblastoma should include HDAC2 in its profile in order to directly target MYC´s trans-activating and trans-repressing function.
2020-09-01 | GSE143384 | GEO
Project description:Several basic helix-loop-helix (bHLH) transcription factors are upregulated in Sonic Hedgehog subgroup of medulloblastoma (SHH MB). Olig2, a neural bHLH transcription factor known to regulate differentiation of neural cell populations, is broadly expressed in mouse models of SHH MB. ChIP-Seq of Olig2 revealed its binding to a large number of sites near genes known to promote SHH MB tumorigenesis, suggesting a potential role for Olig2 in regulating transcriptional programme of MB.
2024-03-23 | GSE103824 | GEO
Project description:MYC is a driver oncogene in many cancers. Inhibition of MYC promises high therapeutic potential, but specific MYC inhibitors remain unavailable for clinical use. Previous studies suggest that MYC amplified Medulloblastoma cells are vulnerable to HDAC inhibition. Using co-immunoprecipitation, mass spectrometry and ChIP-sequencing we show that HDAC2 is a cofactor of MYC in MYC amplified primary medulloblastoma and cell lines. The MYC-HDAC2 complex is bound to genes defining the MYC-dependent transcriptional profile. Class I HDAC inhibition leads to stabilization and reduced DNA binding of MYC protein inducing a down-regulation of MYC activated genes (MAGs) and up-regulation of MYC repressed genes (MRGs). MAGs and MRGs are characterized by opposing biological functions and distinct E-box distribution. We conclude that MYC and HDAC2 (class I) are localized in a complex in MYC amplified medulloblastoma and drive a MYC-specific transcriptional program, which is reversed by the class I HDAC inhibitor entinostat. Thus, the development of HDAC inhibitors for treatment of MYC amplified medulloblastoma should include HDAC2 in its profile in order to directly target MYC´s trans-activating and trans-repressing function.
2020-09-01 | GSE143376 | GEO
Project description:MYC is a driver oncogene in many cancers. Inhibition of MYC promises high therapeutic potential, but specific MYC inhibitors remain unavailable for clinical use. Previous studies suggest that MYC amplified Medulloblastoma cells are vulnerable to HDAC inhibition. Using co-immunoprecipitation, mass spectrometry and ChIP-sequencing we show that HDAC2 is a cofactor of MYC in MYC amplified primary medulloblastoma and cell lines. The MYC-HDAC2 complex is bound to genes defining the MYC-dependent transcriptional profile. Class I HDAC inhibition leads to stabilization and reduced DNA binding of MYC protein inducing a down-regulation of MYC activated genes (MAGs) and up-regulation of MYC repressed genes (MRGs). MAGs and MRGs are characterized by opposing biological functions and distinct E-box distribution. We conclude that MYC and HDAC2 (class I) are localized in a complex in MYC amplified medulloblastoma and drive a MYC-specific transcriptional program, which is reversed by the class I HDAC inhibitor entinostat. Thus, the development of HDAC inhibitors for treatment of MYC amplified medulloblastoma should include HDAC2 in its profile in order to directly target MYC´s trans-activating and trans-repressing function.
2020-09-01 | GSE143379 | GEO
Project description:MYC-driven Group 3 medulloblastoma (MB) (subtype II) is a highly aggressive childhood brain tumor. Sensitivity of MYC-driven MBs to class I histone deacetylase inhibitors (HDACi) has been previously demonstrated in vitro and in vivo. We here characterize the transcriptional effects of class I HDAC inhibition in MYC-driven MB and explore beneficial drug combinations. MYC-amplified Group 3 MB cells (HD-MB03) were treated with class I HDACi entinostat. Changes in the gene expression profile compared to untreated control were quantified on a microarray. Gene set enrichment analysis, cytoscape enrichment mapping and ingenuity pathway analysis led to the identification of pathways affected by entinostat treatment. Five drugs interfering with these pathways (olaparib, idasanutlin, ribociclib, selinexor, vinblastine) were tested as single agents in metabolic activity assays in three MYC-amplified and two non-MYC-amplified MB cell lines. Synergy with entinostat was evaluated by dose response curve shift, combination index and zero interaction potency synergy model and validated in cell count and flow cytometry experiments in two MYC-amplified and one non-MYC-amplified MB cell line. The effect of the most promising drug combination (entinostat and olaparib) on DNA damage was evaluated by γH2A.X quantification in immunoblotting, fluorescence microscopy and flow cytometry. Entinostat treatment changed the expression of genes involved in 22 pathways, including downregulation of DNA damage response. The PARP1 inhibitors olaparib and pamiparib showed synergy with entinostat. The combination of entinostat and olaparib led to increased cell death, decreased viability and increased formation of double strand breaks selectively in MYC-amplified MB cells. MYC-amplified MB cells treated with entinostat and olaparib were particularly vulnerable to additional induction of DNA damage by doxorubicin. Non-MYC-amplified MB cells and normal human fibroblasts were not susceptible to this triple treatment. Our study identifies the combination of entinostat with olaparib and doxorubicin as a new potential therapeutic approach for MYC-driven Group 3 MB.
2023-10-04 | GSE232148 | GEO
Project description:MYC-driven medulloblastoma (MB) is an aggressive pediatric brain tumor characterized by therapy resistance and disease recurrence. Here we integrated data from unbiased genetic screening and metabolomic profiling to identify multiple cancer-selective metabolic vulnerabilities in MYC-driven MB tumor cells, which are amenable to therapeutic targeting. Among these targets, dihydroorotate dehydrogenase (DHODH), an enzyme that catalyzes de novo pyrimidine biosynthesis, emerged as a favorable candidate for therapeutic targeting. Mechanistically, DHODH inhibition acts on-target leading to uridine metabolite scarcity and hyperlipidemia, accompanied by reduced protein O-GlcNAcylation and c-Myc degradation. Pyrimidine starvation evokes a metabolic stress response that leads to cell cycle arrest and apoptosis. We further show that an orally available small molecule DHODH inhibitor demonstrates potent mono-therapeutic efficacy against patient-derived MB xenografts in vivo. The reprogramming of pyrimidine metabolism in MYC-driven medulloblastoma represents an unappreciated therapeutic strategy and a potential new class of treatments with stronger cancer selectivity and fewer neurotoxic sequelae.
2022-11-09 | GSE214956 | GEO