Glioblastoma initiation, migration, and cell types are regulated by core bHLH transcription factors ASCL1 and OLIG2 [ChIP-seq]
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE247977 | GEO | 2024/06/30
REPOSITORIES: GEO
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Project description:Glioblastomas (GBMs) are highly aggressive, infiltrative, and heterogeneous brain tumors driven by complex driver mutations and glioma stem cells (GSCs). The neurodevelopmental transcription factors ASCL1 and OLIG2 are co-expressed in GBMs, but their role in regulating the heterogeneity and hierarchy of GBM tumor cells is unclear. Here, we show that oncogenic driver mutations lead to dysregulation of ASCL1 and OLIG2, which function redundantly to initiate brain tumor formation in a mouse model of GBM. Subsequently, the dynamic levels and reciprocal binding of ASCL1 and OLIG2 to each other and to downstream target genes then determine the cell types and degree of migration of tumor cells. Single-cell RNA sequencing (scRNA-seq) reveals that a high level of ASCL1 is key in defining GSCs by upregulating a collection of ribosomal protein, mitochondrial, neural stem cell (NSC), and cancer metastasis genes – all essential for sustaining the high proliferation, migration, and therapeutic resistance of GSCs.
2024-06-30 | GSE247650 | GEO
Project description:In this study, we explored the transcriptomic consequences of strong activation of the Notch pathway in embryonic human neural stem cells and in gliomas. For this we used a forced expression of the Notch intracellular domain (NICD). Glioblastoma multiforms (GBMs) are highly vascularized brain tumors containing a subpopulation of multipotent cancer stem cells. These cells closely interact with endothelial cells in neurovascular niches. In this study we have uncovered a close link between the Notch1 pathway and the tumoral vascularization process of GBM stem cells. We observed that although the Notch1 receptor was activated, the typical target proteins (HES5, HEY1, HEY2) were not or barely expressed in two explored GBM stem cell cultures. Notch1 signalling activation by expression of the intracellular form (NICD) in these cells was found to reduce their growth rate and migration which was accompanied by the sharp reduction of neural stem cell transcription factor expression (ASCL1, OLIG2, SOX2) while HEY1/2, KLF9, SNAI2 transcription factors were upregulated. Expression of OLIG2 and growth were restored after termination of Notch1 stimulation. Remarkably, NICD expression induced the expression of pericyte cell markers (NG2, PDGFRb and a-smooth muscle actin (aSMA)) in GBM stem cells. This was paralleled with the induction of several angiogenesis-related factors most notably cytokines (HB-EGF, IL8, PLGF), metalloprotease (MMP9) and adhesion proteins (VCAM-1, ICAM-1, ITGA9). In xenotransplantation experiments, contrasting with the infiltrative and poorly-vascularized tumors obtained with control GBM stem cells, Notch1 stimulation resulted in poorly-disseminating but highly-vascularized grafts containing large vessels with lumen. Notch1-stimulated GBM cells expressed pericyte cell markers and closely associated with endothelial cells. These results reveal an important role for the Notch1 pathway in regulating GBM stem cell plasticity and angiogenic properties. Embryonic human neural progenitors obtained from Lonza, the U87 glioma cell line, and glioma cancer stem cells (Gb4 and Gb7) characterized in Guichet et al. (Glia, 2013, 61(2), 225-39) were infected with lentiviruses expressing YFP or YFP-IRES-NICD (activated form of Notch receptor). After 48h, RNA were extracted for Affymetrix microarray analysis.
2014-06-04 | E-GEOD-44561 | biostudies-arrayexpress
Project description:The basic helix-loop-helix proteins Olig1 and Olig2 are expressed in high grade, aggressive human glioblastoma multiformes (GBMs). Here we investigated genetic mechanisms regulating Olig1/2 function during gliomagenesis. Although Olig2 function is necessary for early-aggressive tumor formation in a genetically relevant model of classic GBMs with intact p53 function, late-onset gliomas do eventually form. Using an unbiased approach, we identified Id4, encoding a negative HLH protein, as a gene target potently repressed by Olig2 in glioma progenitors. Although Id4 is thought to antagonize proneural genes involved in differentiation, we report a paradoxical role for Id4 in glioma. Genetic deletion of Id4 converts Olig2-/- gliomas to the early-aggressive form, and conversely, overexpression of Id4 inhibits intact Olig2 and prevents even late-onset tumors. Olig1 overexpression is sufficient for gliomagenesis in an Id4-dependent manner. Together, these findings indicate that gliomagenic factors Olig1 and Olig2 are opposed by Id4 function, which acts as tumor suppressor in p53-intact gliomas.
2018-01-02 | GSE44151 | GEO
Project description:Glioblastoma multiforme (GBM), a grade IV astrocytoma, is the most common and aggressive brain tumor in adults, characterized by being highly infiltrative, angiogenic, and resistant to chemotherapy and radiotherapy. In previous works, has been determined that progesterone P4 increases proliferation, migration and invasion of cells derived from human GBMs through the interaction with its intracellular receptor (PR). In breast cancer, there exist evidence that P4 regulates the expression of miRNAs with tumor suppressor or oncogenic action, via the classical PR. The signature of miRNAs affected by P4 treatment in cells derived from human GBMs has not been determined. Therefore, we studied the effect of P4 on miRNAs expression pattern in U251 cells derived from a human GBM.
2020-01-25 | GSE144204 | GEO
Project description:In this study, we explored the transcriptomic consequences of strong activation of the Notch pathway in embryonic human neural stem cells and in gliomas. For this we used a forced expression of the Notch intracellular domain (NICD). Glioblastoma multiforms (GBMs) are highly vascularized brain tumors containing a subpopulation of multipotent cancer stem cells. These cells closely interact with endothelial cells in neurovascular niches. In this study we have uncovered a close link between the Notch1 pathway and the tumoral vascularization process of GBM stem cells. We observed that although the Notch1 receptor was activated, the typical target proteins (HES5, HEY1, HEY2) were not or barely expressed in two explored GBM stem cell cultures. Notch1 signalling activation by expression of the intracellular form (NICD) in these cells was found to reduce their growth rate and migration which was accompanied by the sharp reduction of neural stem cell transcription factor expression (ASCL1, OLIG2, SOX2) while HEY1/2, KLF9, SNAI2 transcription factors were upregulated. Expression of OLIG2 and growth were restored after termination of Notch1 stimulation. Remarkably, NICD expression induced the expression of pericyte cell markers (NG2, PDGFRb and a-smooth muscle actin (aSMA)) in GBM stem cells. This was paralleled with the induction of several angiogenesis-related factors most notably cytokines (HB-EGF, IL8, PLGF), metalloprotease (MMP9) and adhesion proteins (VCAM-1, ICAM-1, ITGA9). In xenotransplantation experiments, contrasting with the infiltrative and poorly-vascularized tumors obtained with control GBM stem cells, Notch1 stimulation resulted in poorly-disseminating but highly-vascularized grafts containing large vessels with lumen. Notch1-stimulated GBM cells expressed pericyte cell markers and closely associated with endothelial cells. These results reveal an important role for the Notch1 pathway in regulating GBM stem cell plasticity and angiogenic properties.
2014-06-04 | GSE44561 | GEO
Project description:Glioblastoma (GBM) is the most common and most aggressive primary brain tumor in adults. The existence of a small population of stem-like tumor cells that efficiently propagate tumors and resist cytotoxic therapy is one proposed mechanism leading to the resilient behavior of tumor cells and poor prognosis. In this study, we performed an in-depth analysis of the DNA methylation landscape in GBM-derived cancer stem cells (GSCs). Parallel comparisons of primary tumors and GSC lines derived from these tumors with normal controls (a neural stem cell (NSC) line and normal brain tissue) identified groups of hyper- and hypomethylated genes that display a trend of either increasing or decreasing methylation levels in the order of controls, primary GBMs, and their counterpart GSC lines, respectively. Interestingly, concurrent promoter hypermethylation and gene body hypomethylation were observed in a subset of genes including MGMT, AJAP1 and PTPRN2. These unique DNA methylation signatures were also found in primary GBM-derived xenograft tumors indicating that they are not tissue culture-related epigenetic changes. Integration of GSC-specific epigenetic signatures with gene expression analysis further identified candidate tumor suppressor genes that are frequently down regulated in GBMs such as SPINT2, NEFM and PENK. Forced re-expression of SPINT2 reduced glioma cell proliferative capacity, anchorage independent growth, cell motility, and tumor sphere formation in vitro. The results from this study demonstrate that GSCs possess unique epigenetic signatures that may play important roles in the pathogenesis of GBM. The reduced representation bisulfite sequencing (RRBS) approach (Meissner et al., 2008) was used to generate genome-wide single-base resolution CpG methylation profiles of three primary GBMs (1063T, 1133T, and 1142T) and three GSC lines (1063S, 1133S, 1142S) derived from these primary GBM tumors. The NSC line and the normal brain (NB) tissue sample were used as controls for comparison purposes. In addition, we analyzed three GBM xenograft tumor tissue samples (Mayo22, Mayo39, Mayo59) developed by Dr. Jann N. Sarkaria of Mayo Clinic.
2015-06-24 | E-GEOD-70175 | biostudies-arrayexpress
Project description:Overexpression of TAZ in GSCs abrogated neuronal differentiation by re-alignment of the enhancer landscape and down-regulation of key master TFs associated with neurogenesis such as OLIG2 and ASCL1.
2023-03-01 | GSE139139 | GEO
Project description:Glioblastoma (GBM) is the most aggressive primary brain tumor characterized by infiltrative migration of malignant glioma cells into the surrounding brain parenchyma. In this study, our analysis of GBM patient cohorts displayed significant higher expression of Glycosyltransferase 8 domain containing 1 (GLT8D1) compared to normal brain tissue and could be associated with impaired patient survival. Increased in vitro expression of GLT8D1 significantly enhanced migration of two different sphere-forming GBM cell lines. By in silico analysis we predicted the 3D-structure as well as the active site residues of GLT8D1. The introduction of point mutations in the predicted active site reduced its glycosyltransferase activity in vitro and consequently impaired GBM tumor cell migration. Examination of GLT8D1 interaction partners by LC-MS/MS implied proteins associated with cytoskeleton and intracellular transport as potential substrates. In conclusion, we demonstrated that the enzymatic activity of glycosyltransferase GLT8D1 promotes GBM cell migration.
2022-04-04 | PXD027854 | Pride
Project description:Glioblastoma (GBM) is the most common primary brain tumor in adults with a median survival of approximately 15 months, therefore, more effective treatment options for GBM are required. To identify new drugs targeting glioblastomas, we performed a high throughput drug screen using patient-derived neurospheres cultured to preferentially retain their glioblastoma stem cell (GSC) phenotype.
High throughput drug screening was performed on GSCs followed by a second dose response assay of the 5 identified original hits. A PI3K/mTOR dependency to a proteasome inhibitor (carfilzomib), was confirmed by gain of function and loss of function experiments. Proteasome inhibition response signatures were derived from proteomic and bioinformatic analysis. Molecular mechanism of action was determined using in vitro 3-dimensional (3D) GBM organoid models and in vivo preclinical orthotopic GBM models.
We found that GSCs were highly sensitive to proteasome inhibition due to an underlying dependency on an increased protein synthesis rate, and loss of autophagy, associated with PTEN loss and activation of the PI3K/mTOR pathway. In contrast, combinatory inhibition of autophagy and the proteasome, resulted in enhanced cytotoxicity specifically in GSCs that did express PTEN. Finally, proteasome inhibition specifically increased cell death markers in 3D glioblastoma organoids, suppressed tumor growth, and increased survival of mice orthotopically engrafted with GSCs. As perturbations of the PTEN/ PI3K axis occur in nearly 50% of GBMs, these findings suggest that a significant fraction of these tumors could be vulnerable to proteasome inhibition.
2020-12-04 | MSV000086560 | MassIVE
Project description:Glioblastoma (GBM) is the most prevalent primary malignant brain tumor, containing self-renewing stem-like GBM stem cells (GSCs) that have been a focus of immunotherapies. Chimeric antigen receptor (CAR) T cell therapy has shown evidence of clinical activity, but overall limited responses in patients with GBMs. Here, we interrogated molecular determinants of CAR T cell-mediated GBM killing through whole-genome CRISPR screens in both CAR T cells and patient-derived GSCs. CRISPR screening of CAR T cells identified dependencies for their effector functions, including TLE4 and IKZF2. Targeted knockout of these genes in CAR T cells robustly enhanced antitumor efficacy against GBM patient-derived xenografts (PDXs). Bulk and single cell-RNA sequencing of edited CAR T cells revealed transcriptional profiles of superior effector function and inhibited exhaustion responses. Reciprocal screening of GSCs identified genes essential for their susceptibility to CAR-mediated killing, including RELA and NPLOC4, the knockout of which altered the tumor-immune signaling axis and increased responsiveness of CAR therapy. Overall, CRISPR screening of CAR T cells and GSCs are promising strategies to discover avenues and inform potential combinatorial approaches for enhancing CAR T cell therapeutic efficacy against GBM, and can be extended to reveal key mediators of immunotherapy responses across solid tumors.
2021-05-19 | GSE163401 | GEO