CHROMATIN LANDSCAPES REVEAL DEVELOPMENTALLY ENCODED TRANSCRIPTIONAL STATES THAT DEFINE GLIOBLASTOMA [RNA-Seq]
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE119834 | GEO | 2019/03/18
REPOSITORIES: GEO
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Project description:Glioblastoma is an incurable brain cancer characterized by high genetic and pathological heterogeneity. Here we mapped active chromatin landscapes with gene expression, whole-exomes, copy number profiles, and DNA methylomes across 44 glioblastoma stem cell (GSCs) models, 50 primary glioblastomas, and 10 neural stem cells (NSCs) with the goal of identifying essential super enhancer (SE)-associated genes and the core transcription factors that establish them and glioblastoma identity. Glioblastomas segregate with two dominant enhancer profiles that coopt unique developmental transcription factor regulatory programs to enforce tumor identity. From group specific enhancer profiles, we inferred core transcription factors that define subgroup identity. These transcription factors show higher activity in glioblastomas versus normal neural stem cells, are associated with poor clinical outcomes, and are required for glioblastoma growth in vitro and in vivo. Given challenges with genetically-defined targeted therapies for glioblastoma, we propose targeting underlying transcriptional identity may serve as an important therapeutic strategy.
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Project description:Chavez2009 - a core regulatory network of OCT4 in human embryonic stem cells
A core OCT4-regulated network has been identified as a test case, to analyase stem cell characteristics and cellular differentiation.
This model is described in the article:
In silico identification of a core regulatory network of OCT4 in human embryonic stem cells using an integrated approach.
Chavez L, Bais AS, Vingron M, Lehrach H, Adjaye J, Herwig R
BMC Genomics, 2009, 10:314
Abstract:
BACKGROUND: The transcription factor OCT4 is highly expressed in pluripotent embryonic stem cells which are derived from the inner cell mass of mammalian blastocysts. Pluripotency and self renewal are controlled by a transcription regulatory network governed by the transcription factors OCT4, SOX2 and NANOG. Recent studies on reprogramming somatic cells to induced pluripotent stem cells highlight OCT4 as a key regulator of pluripotency.
RESULTS: We have carried out an integrated analysis of high-throughput data (ChIP-on-chip and RNAi experiments along with promoter sequence analysis of putative target genes) and identified a core OCT4 regulatory network in human embryonic stem cells consisting of 33 target genes. Enrichment analysis with these target genes revealed that this integrative analysis increases the functional information content by factors of 1.3 - 4.7 compared to the individual studies. In order to identify potential regulatory co-factors of OCT4, we performed a de novo motif analysis. In addition to known validated OCT4 motifs we obtained binding sites similar to motifs recognized by further regulators of pluripotency and development; e.g. the heterodimer of the transcription factors C-MYC and MAX, a prerequisite for C-MYC transcriptional activity that leads to cell growth and proliferation.
CONCLUSION: Our analysis shows how heterogeneous functional information can be integrated in order to reconstruct gene regulatory networks. As a test case we identified a core OCT4-regulated network that is important for the analysis of stem cell characteristics and cellular differentiation. Functional information is largely enriched using different experimental results. The de novo motif discovery identified well-known regulators closely connected to the OCT4 network as well as potential new regulators of pluripotency and differentiation. These results provide the basis for further targeted functional studies.
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2005-01-01 | MODEL1305010000 | BioModels
Project description:Recent studies demonstrated that tumor cells with stem cell-like properties can be cultured from human glioblastomas by using conditions that select for the expansion of neural stem cells. We established glioblastoma stem-like (GS-) cell cultures from 9 different glioblastomas, 8 of which generated stably expandable cell lines. Analyzing GS-cell cultures, we discovered two clearly discernable phenotypes. Microarray analysis showed that the 4 GSf cell lines shared expression profiles dominated by genes involved in nervous system development and neuropeptide signaling, while the 5 GSr lines shared expression signatures enriched for extracellular matrix-proteins. Keywords: Cell line comparison
2007-12-04 | GSE8049 | GEO