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GSE31215
Homo sapiens
8 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Cancer stem cells (CSCs) display plasticity and self-renewal properties reminiscent of normal tissue stem cells, but the events responsible for their emergence remain obscure. We recently identified CSCs in Ewing sarcoma family tumors (ESFTs) and showed that they retain mesenchymal stem cell (MSC) plasticity. In the present study, we addressed the mechanisms that underlie ESFT CSC development. We show that the EWS-FLI-1 fusion gene, associated with 85%-90% of ESFTs and believed to initiate their pathogenesis, induces expression of the embryonic stem cell (ESC) genes OCT4, SOX2, and NANOG in human pediatric MSCs (hpMSCs) but not in their adult counterparts. Moreover, under appropriate culture conditions, hpMSCs expressing EWS-FLI-1 generate a cell subpopulation displaying ESFT CSC features in vitro. We further demonstrate that induction of the ESFT CSC phenotype is the result of the combined effect of EWS-FLI-1 on its target gene expression and repression of microRNA-145 (miRNA145) promoter activity. Finally, we provide evidence that EWS-FLI-1 and miRNA-145 function in a mutually repressive feedback loop and identify their common target gene, SOX2, in addition to miRNA145 itself, as key players in ESFT cell differentiation and tumorigenicity. Our observations provide insight for the first time into the mechanisms whereby a single oncogene can reprogram primary cells to display a CSC phenotype.
Publication Title
EWS-FLI-1 modulates miRNA145 and SOX2 expression to initiate mesenchymal stem cell reprogramming toward Ewing sarcoma cancer stem cells.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 13 Downloadable Samples
NextSeq 500
Description
Diffuse intrinsic pontine glioma (DIPG) is a universally fatal malignancy of the childhood central nervous system, with a median overall survival of 9-11 months. We have previously shown that primary DIPG tissue contains numerous tumor-associated macrophages, and substantial work has demonstrated a significant pathological role for adult glioma-associated macrophages. However, work over the past decade has highlighted many molecular and genomic differences between pediatric and adult glioblastomas (GBM). Thus, we directly compared inflammatory characteristics of DIPG and adult GBM. We found that the leukocyte (CD45+) compartment in primary DIPG tissue samples is predominantly composed of CD11b+ macrophages, with very few CD3+ T-lymphocytes. In contrast, T-lymphocytes are more abundant in adult GBM tissue samples. RNA sequencing of macrophages isolated from primary tumor samples revealed that DIPG- and adult GBM-associated macrophages both express gene programs related to ECM remodeling and angiogenesis, but DIPG-associated macrophages express substantially fewer inflammatory factors than their adult GBM counterparts. Examining the secretome of glioma cells, we found that patient-derived DIPG cell cultures secrete markedly fewer cytokines and chemokines than patient-derived adult GBM cultures. Concordantly, bulk and single-cell RNA sequencing data indicates low to absent expression of chemokines and cytokines in DIPG. Together, these observations suggest that the inflammatory milieu of the DIPG tumor microenvironment is fundamentally different than adult GBM. The low intrinsic inflammatory signature of DIPG cells may contribute to the lack of lymphocytes and non-inflammatory phenotype of DIPG-associated microglia/macrophages. Understanding the glioma subtype-specific inflammatory milieu may inform the design and application of immunotherapy-based treatments. Overall design: RNA-seq of primary isolated microglia/macrophages from early post-mortem DIPG tissue samples, pediatric normal cortex, and adult GBM tissue samples. Libraries were sequenced on Illumina NextSeq 500, 1x75.
Publication Title
Non-inflammatory tumor microenvironment of diffuse intrinsic pontine glioma.
Sample Metadata Fields
Sex, Specimen part, Subject
View Samples- Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Overexpression of the Polycomb group protein Enhancer of Zeste Homolog 2 (EZH2) occurs in diverse malignancies, including prostate cancer, breast cancer, and glioblastoma multiforme (GBM) (1). Based on its ability to modulate transcription of key genes implicated in cell cycle control, DNA repair and cell differentiation, EZH2 is believed to play a crucial role in tissue-specific stem cell maintenance and tumor development. Here we show that targeted pharmacologic disruption of EZH2 by the S-adenosylhomocysteine hydrolase inhibitor 3-Deazaneplanocin A (DZNep), or its specific down-regulation by shRNA, strongly impairs GBM cancer stem cell self-renewal in vitro and tumor-initiating capacity in vivo. Using genome-wide expression analysis of DZNep-treated GBM cancer stem cells, we found the expression of c-myc, recently reported to be essential for GBM cancer stem cells, to be strongly repressed upon EZH2 depletion. Specific shRNA-mediated down-regulation of EZH2 in combination with chromatin immunoprecipitation (ChIP) experiments revealed that c-myc is a direct target of EZH2 in GBM cancer stem cells. Taken together, our observations provide evidence that direct transcriptional regulation of c-myc by EZH2 may constitute a novel mechanism underlying GBM cancer stem cell maintenance and suggest that EZH2 may be a valuable new therapeutic target for GBM management.
Publication Title
EZH2 is essential for glioblastoma cancer stem cell maintenance.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Homo sapiens
- 12 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
An aberrant transcription factor network essential for Wnt signaling and stem cell maintenance in glioblastoma.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 12 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Glioblastoma (GBM) is thought to be driven by a sub-population of cancer stem cells (CSCs) that self-renew and recapitulate tumor heterogeneity, yet remain poorly understood. Here we present a comparative epigenomic analysis of GBM CSCs that reveals widespread activation of genes normally held in check by Polycomb repressors. These activated targets include a large set of developmental transcription factors (TFs) whose coordinated activation is unique to the CSCs. We demonstrate that a critical factor in the set, ASCL1, activates Wnt signaling by repressing the negative regulator DKK1. We show that ASCL1 is essential for maintenance and in vivo tumorigenicity of GBM CSCs. Genomewide binding profiles for ASCL1 and the Wnt effector LEF1 provide mechanistic insight and suggest widespread interactions between the TF module and the signaling pathway. Our findings demonstrate regulatory connections between ASCL1, Wnt signaling and collaborating TFs that are essential for the maintenance and tumorigenicity of GBM CSCs.
Publication Title
An aberrant transcription factor network essential for Wnt signaling and stem cell maintenance in glioblastoma.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 9 Downloadable Samples
Description
Many cancers are postulated to harbor developmental hierarchies in which cells display variability in stem-like character, tumor propagating ability, and proliferation. In glioblastoma (GBM), glioma stem cells (GSCs) reside atop such a tumor cellular hierarchy, and are thought to resist current therapies and thus underlie inevitable relapse. Here we show that GSCs can evade RTK inhibition by reversibly regressing to a slow-cycling state reminiscent of quiescent neural stem cells. This process involves up-regulation of numerous histone demethylases, including KDM6A/B, which remodel the chromatin landscape and are selectively essential for drug persister survival. Chromatin remodeling is accompanied by activation of various neurodevelopmental master regulators and Notch signaling, changes which closely parallel critical aspects of neural stem cell biology. Thus our findings illustrate how cancer cells may hijack native developmental programs for deranged proliferation, adaptation, and tolerance in the face of stress. Our studies highlight key roles for chromatin remodeling and developmental plasticity in GBM biology, and suggest strategies for overcoming therapeutic resistance by targeting epigenetic and developmental pathways. Overall design: ChIP-seq for histone modifications and Notch factors in glioblastoma stem cell lines with various drug treatments RNA-seq in glioblastoma stem cell lines with various drug treatments
Publication Title
Adaptive Chromatin Remodeling Drives Glioblastoma Stem Cell Plasticity and Drug Tolerance.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 12 Downloadable Samples
- Illumina HiSeq 2000
Description
Gene expression in livers of adult male mice subjected to continuous GH infusion using Alzet osmotic minipumps for 1, 4 or 7 days was assayed by RNA-seq, as part of a study of growth hormone regulation of hepatic lincRNAs (PMID:26459762) and protein-coding genes (PMID:28694329). Overall design: RNA isolated from livers obtained from untreated male mice, or from male mice subjected to continuous GH tratment for 1, 4 or 7 days were prepared and used for unstranded RNA-seq.
Publication Title
Feminization of Male Mouse Liver by Persistent Growth Hormone Stimulation: Activation of Sex-Biased Transcriptional Networks and Dynamic Changes in Chromatin States.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 12 Downloadable Samples
- Illumina HiSeq 2500
Description
rRNA-depleted RNA isolated from livers of intact male and female mice and from male mice treated with a continuous infusion of growth hormone for either 10 hr or 1 days was analyzed by RNA-seq Overall design: Liver RNA was isolated from 8 week old male mice treated with a continuous GH infusion (cGH) for either 10 hours or 1 day. Sham pump males served as a control. RNA-seq data are compared to untreated adult females to identify genes that show sex differences in liver expression and also respond to cGH. RNA samples were pooled to make 3 biological replicates per condition comprised of 2-4 individuals each.
Publication Title
Feminization of Male Mouse Liver by Persistent Growth Hormone Stimulation: Activation of Sex-Biased Transcriptional Networks and Dynamic Changes in Chromatin States.
Sample Metadata Fields
Sex, Age, Cell line, Treatment, Subject
View Samples- Homo sapiens
- 6 Downloadable Samples
- IlluminaHiSeq2000
Description
We show that EWS-FLI1, an aberrant transcription factor responsible for the pathogenesis of Ewing sarcoma, reprograms gene regulatory circuits by directly inducing or directly repressing enhancers. At GGAA repeats, which lack regulatory potential in other cell types and are not evolutionarily conserved, EWS- FLI1 multimers potently induce chromatin opening, recruit p300 and WDR5, and create de novo enhancers. GGAA repeat enhancers can loop to physically interact with target promoters, as demonstrated by chromosome conformation capture assays. Conversely, EWS-FLI1 inactivates conserved enhancers containing canonical ETS motifs by displacing wild-type ETS transcription factors and abrogating p300 recruitment. Overall design: Ewing sarcoma cell lines (A673 and SKNMC) were analyzed by RNA-seq. EWS-FLI1 was depleted by infection with lentiviral shRNAs (shFLI1 and shGFP control).
Publication Title
EWS-FLI1 utilizes divergent chromatin remodeling mechanisms to directly activate or repress enhancer elements in Ewing sarcoma.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 8 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Metabolically active cells require robust mechanisms to combat oxidative stress. The cytoplasmic thioredoxin reductase/thioredoxin (Txnrd1/Txn1) system maintains reduced protein dithiols and provides electrons to some cellular reductases, including peroxiredoxins.
Publication Title
Cytoprotective Nrf2 pathway is induced in chronically txnrd 1-deficient hepatocytes.
Sample Metadata Fields
Specimen part
View Samples