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SRP066863
Mus musculus
4 Downloadable Samples
NextSeq 500
Description
Introduction: Glioma stem cells isolated from human glioblastomas are resistant to radiation and cytotoxic chemotherapy and may drive tumor recurrence. Treatment efficacy may depend on the presence of glioma stem cells, expression of DNA repair enzymes such as methylguanine methyltransferase (MGMT), or transcriptome subtype. Methods: To model genetic alterations in the core signaling pathways of human glioblastoma, we induced conditional Rb knockout, Kras activation, and Pten deletion mutations in cortical murine astrocytes. Serial neurosphere culture, multi-lineage differentiation, and orthotopic transplantation were used to assess whether these mutations induced de-differentiation of cortical astrocytes into glioma stem cells. Efficacy of radiation and temozolomide was examined in vitro and in an allograft model in vivo. The effects of radiation on transcriptome subtype was examined by expression profiling. Results: G1/S-defective, Rb knockout astrocytes gained unlimited self-renewal and multi-lineage differentiation capacity, in both the presence and absence of Kras and Pten mutations. Only triple mutant astrocytes formed serially-transplantable glioblastoma allografts. Triple mutant astrocytes and allografts were sensitive to radiation, but expressed Mgmt and were resistant to temozolomide. Radiation induced a shift in transcriptome subtype of glioblastoma allografts from proneural to mesenchymal. Conclusion: A defined set of core signaling pathway mutations induces de-differentiation of cortical murine astrocytes into glioma stem cells. This non-germline genetically engineered mouse model mimics human proneural glioblastoma on histopathological, molecular, and treatment response levels. It may be useful in dissecting the genetic and cellular mechanisms of treatment resistance and developing more effective therapies. Overall design: Investigation of chromatin accessibility in astrocytes and glioblastoma cell lines
Publication Title
Core pathway mutations induce de-differentiation of murine astrocytes into glioblastoma stem cells that are sensitive to radiation but resistant to temozolomide.
Sample Metadata Fields
Cell line, Subject
View Samples- Homo sapiens
- 10 Downloadable Samples
- IlluminaHiSeq2000
Description
Biochemical fractionation of HEK293 nuclei and RNA-seq of chromatin-associated and soluble-nuclear RNA. Overall design: Nuclei from three biological replicates were isolated by detergent lysis, fractionated, then three chromatin and three soluble RNA samples were converted to cDNA using Illumina TruSeq stranded protocol, and sequenced on Illumina HiSeq2000
Publication Title
Nuclear Fractionation Reveals Thousands of Chromatin-Tethered Noncoding RNAs Adjacent to Active Genes.
Sample Metadata Fields
No sample metadata fields
View Samples- Drosophila melanogaster
- 16 Downloadable Samples
Affymetrix Drosophila Genome 2.0 Array (drosophila2)
Description
The rapid evolution of toxin resistance in animals has important consequences for the ecology of species and our economy. Pesticide resistance in insects has been a subject of intensive study, however, very little is known about how Drosophila species became resistant to natural toxins with ecological relevance, such as -amanitin that is produced in deadly poisonous mushrooms. Here we performed a microarray study to elucidate the genes, chromosomal loci, molecular functions, biological processes, and cellular components that contribute to the -amanitin resistance phenotype in Drosophila melanogaster. We suggest that toxin entry blockage through the cuticle, phase I and II detoxification, sequestration in lipid particles, and proteolytic cleavage of -amanitin contribute in concert to this quantitative trait. We speculate that the resistance to mushroom toxins in Drosophila melanogaster and perhaps in mycophagous Drosophila species has evolved as a cross-resistance to pesticides or other xenobiotic substances.
Publication Title
The mechanisms underlying α-amanitin resistance in Drosophila melanogaster: a microarray analysis.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 7 Downloadable Samples
- Affymetrix Murine Genome U74A Array (mgu74a)
Description
Comparison of sense (forward probes) and antisense (reverse probes on U74 v1 gene arrays) transcripts in mouse kidney and brain.
Publication Title
Expression profiling of antisense transcripts on DNA arrays.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 5 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Commonalities and dissimilarities between the IGF1R and INSR pathways
Publication Title
Systems Analysis of Insulin and IGF1 Receptors Networks in Breast Cancer Cells Identifies Commonalities and Divergences in Expression Patterns.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 20 Downloadable Samples
- Affymetrix Human Gene 2.1 ST Array (hugene21st)
Description
Identification of filamin-A as a target for insulin and IGF1 action.
Publication Title
Genome-Wide Analyses Identify Filamin-A As a Novel Downstream Target for Insulin and IGF1 Action.
Sample Metadata Fields
Cell line, Treatment
View Samples- Homo sapiens
- 3 Downloadable Samples
- IlluminaHiSeq2000
Description
Background: Eukaryotic cells express a complex layer of noncoding RNAs. An intriguing family of regulatory RNAs includes transcripts from the opposite strand of protein coding genes, so called natural antisense transcripts (NATs). Here, we test the hypothesis that antisense transcription triggers RNA interference and gives rise to endogenous short RNAs (endo-siRNAs). Methods/Results: We used cloned human embryonic kidney cells (HEK293) followed by short RNAseq to investigate the small genic RNA transcriptome. 378 genes gave rise to short RNA reads that mapped to exons of RefSeq genes. The length profile of short RNAs showed a broad peak of 20-24 nucleotides, indicative of endo-siRNAs. Collapsed reads mapped predominantly to the first and the last exon of genes (74%). RNAs reads were intersected with sequences occupied by RNAPolII or bound to Argonaute (AGO1 by crosslinking, ligation, and sequencing of hybrids, CLASH). In the first exon, 94% of the reads correlated with PolII occupancy with an average density of 130 (relative units); this decreased to 65%/20 in middle exons and 54%/12 in the last exon. CLASH reads mapping to multi-exon genes showed little distribution bias with an average of about 5 CLASH reads overlapping with 60% of the endo-siRNA reads. However, endo-siRNAs (21-25 nt) intersecting with CLASH reads were enriched at the 5''end and decreased towards the 3''end. We then investigated the 378 genes with particular focus on features indicative for short RNA production; however, found that endo-siRNA numbers did not correlate with gene structures that favor convergent transcription. In contrast, our gene set was found notably over-represented in the NATsDB sense/antisense group as compared to non-overlapping and non-bidirectional groups. Moreover, read counts showed no correlation with the steady-state levels of the related mRNAs and the pattern of endo-siRNAs proved reproducible after an induced mutagenic insult. Conclusions: Our results suggest that antisense transcripts contribute to low levels of endo-siRNAs in fully differentiated human cells. A characteristic endo-siRNA footprint is being produced at sites of RNAPolII transcription which is also related to AGO1. This endo-siRNA signature represents an intriguing finding and its reproducibility suggests that the production of endo-siRNAs is a regulated process with potential homoeostatic impact. Overall design: Size selected RNASeq of 3 human embryonic kidney cell (HEK293) samples. 1 control and 2 samples exposed to 100 µg/ml ethyl methanesulfonate for 24 hrs.
Publication Title
Contribution of natural antisense transcription to an endogenous siRNA signature in human cells.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 4 Downloadable Samples
- Affymetrix Murine Genome U74A Version 2 Array (mgu74av2)
Description
The loss of loricrin, a major component of the cornified envelope, results in a delay of epidermal barrier formation. Therefore, the living layers of the epidermis are aberrantly exposed to late-stage amniotic fluid, which may serve as the signal to upregulate genes that functionally compensate for the loss of loricrin. Consistent with this hypothesis, metabolomic studies revealed marked changes in amniotic fluid between E14.5 and E16.5 dpc. In addition, we discovered that the Nrf2/Keap1 pathway detects these compositional changes and directly upregulates the expression of genes involved in the compensatory response, thus ensuring postnatal survival. In support of this finding, we demonstrate that genetically blocking the Nrf2 pathway abolishes the compensatory response, and preemptively activating Nrf2 pharmacologically rescues the delay in barrier formation in utero. Our findings reveal that the functions of Nrf2 and the composition of amniotic fluid have co-evolved to ensure the formation of a functional barrier.
Publication Title
Amniotic fluid activates the nrf2/keap1 pathway to repair an epidermal barrier defect in utero.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 81 Downloadable Samples
- IlluminaHiSeq2000
Description
In the present study 23 participants completed three months of supervised aerobic exercise training of one leg (training period 1) followed by 9 months of rest before 12 of the participants completed a second exercise training period (training period 2) of three months of both legs. Skeletal muscle biopsies have been collected before and after the training periods. We have compared trained leg with untrained leg and studied gene and isoform expression. Additional samples included in this study has been previously submitted (GEO accession number GSE58387 and GSE60590). Overall design: Analyze of transcriptome in skeletal muscle biopsy samples in response to exercise training in 23 participants in total (in addition to data previously submitted GEO accession number GSE58387 and GSE60590). Biopsy is collected from skeletal muscle before and after training period.
Publication Title
The Impact of Endurance Training on Human Skeletal Muscle Memory, Global Isoform Expression and Novel Transcripts.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 40 Downloadable Samples
- IlluminaHiSeq2000
Description
A total of 23 participants (data available in present submission and in GSE58608) completed three months of supervised aerobic exercise training of one leg. Skeletal muscle biopsies have been collected before and after the training period. We have investigated differences between trained and untrained leg and before and after training by studying the gene and isoform expression. Additional samples present in this study has been previously published (GEO accession number GSE58608). Overall design: Analysis of transcriptome in skeletal muscle biopsy samples in response to exercise training in 22 participants (of the total 23 participants). One biopsy is collected from each leg before and after training period.
Publication Title
The Impact of Endurance Training on Human Skeletal Muscle Memory, Global Isoform Expression and Novel Transcripts.
Sample Metadata Fields
No sample metadata fields
View Samples