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SRP001995
Caenorhabditis elegans
3 Downloadable Samples
Illumina Genome Analyzer II
Description
Years after the discovery that Dicer is a key enzyme in gene-silencing, the role of its helicase domain remains enigmatic. Here we show that this domain is critical for accumulation of certain endogenous small interfering RNAs (endo-siRNAs) in C. elegans. The domain is required for the production of the direct products of Dicer, or primary endo-siRNAs, and consequently, affects levels of downstream intermediates, the secondary endo-siRNAs. Consistent with the role of endo-siRNAs in silencing, their loss correlates with an increase in cognate mRNA levels. We find that the helicase domain of Dicer is not required for microRNA (miRNA) processing, or RNA interference following exposure to exogenous double-stranded RNA. Comparisons of wildtype and helicase-defective strains using deep-sequencing analyses show that the helicase domain is required by a subset of annotated endo-siRNAs, in particular, those associated with the slightly longer 26 nucleotide small RNA species containing a 5' guanosine. Overall design: We reintroduced either wildtype Dicer, or Dicer harboring a mutation (K39A) in it''s helicase domain, into dcr-1(ok247) mutant worms via transgene rescue. We then used high-throughput sequencing to compare levels of small RNAs present in each of these strains.
Publication Title
Dicer's helicase domain is required for accumulation of some, but not all, C. elegans endogenous siRNAs.
Sample Metadata Fields
Cell line, Subject
View Samples- Mus musculus
- 12 Downloadable Samples
- Illumina HiSeq 2500
Description
RNA was isolated from FFPE samples of IDH1 mutant, WT tumors and normal brains Overall design: Determination of the glioma subtype in IDH1 mutant and WT tumors
Publication Title
Mutant IDH1 Promotes Glioma Formation In Vivo.
Sample Metadata Fields
Specimen part, Subject
View Samples- Mus musculus
- 16 Downloadable Samples
Illumina MouseWG-6 v2.0 expression beadchip
Description
Neuronal migration disorders such as lissencephaly and subcortical band heterotopia (SBH) are associated with epilepsy and intellectual disability. Doublecortin (DCX), LIS1 and alpha1-tubulin (TUBA1A), are mutated in these disorders, however corresponding mouse mutants do not show heterotopic neurons in the neocortex. On the other hand, the spontaneously arisen HeCo mouse mutant displays this phenotype. The study of this model reveals novel mechanisms of heterotopia formation. While, HeCo neurons migrate at the same speed as WT, abnormally distributed dividing progenitors were found throughout the cortical wall from E13. Through genetic studies we identified Eml1 as the mutant gene in HeCo mice. No full length transcripts of Eml1 were identified due to a retrotransposon insertion in an intron. Re-expression of Eml1, coding for a microtubule-associated protein, rescues the HeCo progenitor phenotype. We further show that EML1 is mutated in giant ribbon-like heterotopia in human. Our data link abnormal spindle orientations, ectopic progenitors and severe heterotopia in mouse and human.
Publication Title
Mutations in Eml1 lead to ectopic progenitors and neuronal heterotopia in mouse and human.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 2 Downloadable Samples
- Affymetrix Murine Genome U74A Version 2 Array (mgu74av2)
Description
Our earlier study demonstrated that when CFSE-labeled LCMV-or Pichinde virus-immune spleen leukocytes were transferred into T cell-deficient hosts, the bona fide virus-specific memory cells underwent relatively limited cell division and were substantially diluted in frequency by other more extensively proliferating cells originating from that donor cell population. We questioned how the slowly dividing population, which contained bona fide memory cells, differed from the rapidly dividing cells, which contained memory-like cells. As a preliminary screen we performed a comparative genome-wide microarray analysis of genes expressed on sorted rapidly proliferating (CFSE-low) and slowly proliferating (CFSE-high) CD8 cell populations
Publication Title
Programmed death-1 (PD-1) defines a transient and dysfunctional oligoclonal T cell population in acute homeostatic proliferation.
Sample Metadata Fields
Age, Specimen part
View Samples- Arabidopsis thaliana
- 6 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Comparison of rosette leaves of two different RAP2.2 overexpressing lines with wild type leaves. The AP2/EREBP transcription factor RAP2.2 was shown to bind to a cis-acting motif within the phytoene synthase promoter from Arabidopsis. To investigate effects of increased RAP2.2 levels, two RAP2.2 overexpressing Arabidopsis thaliana (ecotype Wassilewskija) lines were generated: one line, nosr2, carried the nos promoter and showed a two-fold increase in RAP2.2 transcript level, the second line, cmr-5, carried four copies of the CaMV-35S enhancer and showed a 12-fold increase. However, neither weak nor strong increase in RAP2.2 transcript amounts had any effect on RAP2.2 protein levels as shown by Western blot analysis. The strong robustness of RAP2.2 protein levels towards transcriptional changes can be explained by specific protein degradation which includes SINAT2, an E3 ubiquitin ligase which was isolated using a two-hybrid approach. Accordingly, global gene expression analysis using both RAP2.2 overexpressing lines showed only minor transcriptional changes which are probably due to minor growth variation than to mechanisms involved in the down-regulation of RAP2.2 protein amounts.
Publication Title
Transcription factor RAP2.2 and its interacting partner SINAT2: stable elements in the carotenogenesis of Arabidopsis leaves.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 24 Downloadable Samples
- Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
Elevated levels of androgen receptor (AR) in prostate cancer confer resistance to current antiandrogens and play a causal role in disease progression due to persistent target gene activation. Through pharmacologic and genetic approaches, we show that half of all direct AR target genes, including TMPRSS2, the primary driver of ETS fusion transcripts in 70 percent of human prostate cancers, require histone deacetylase (HDAC) activity for transcriptional activation by AR. Surprisingly, the HDAC3-NCoR complex, which typically functions to repress gene expression by nuclear receptors, is required for AR target gene activation. Prostate cancer cells treated with HDAC inhibitors have reduced AR protein levels, but we show that the mechanism of blockade of AR activity is through failure to assemble a coactivator/RNA polymerase II complex after AR binds to the enhancers of target genes. Failed complex assembly is associated with a phase shift in the cyclical wave of AR recruitment that typically occurs in response to ligand treatment. HDAC inhibitors retain the ability to block AR activity in hormone refractory prostate cancer models and therefore merit clinical investigation in this setting. HDAC-regulated AR target genes defined here can serve as biomarkers to ensure sufficient levels of HDAC inhibition.
Publication Title
Histone deacetylases are required for androgen receptor function in hormone-sensitive and castrate-resistant prostate cancer.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 21 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
The Her-2/Neu-positive mouse breast cancer cell line was serially co-cultured with minced brain, bone marrow, and lung tissue in an intravital microscopy chamber mounted on the dorsal skinfold of nude mice, alternating with growth in vitro. Gene expression analysis was performed on the cells grown in culture after sorting and further growth in vitro. Gene expression under these growth conditions differed in time and according to the co-cultivated organ tissue. This study reveals genes that are expressed by cells as they adapt differentially to various foreign tissue microenvironments, and may represent a paradigm to discover gene expression changes that occur immediately upon extravasation when cancer metastasizes.
Publication Title
Effects of different tissue microenvironments on gene expression in breast cancer cells.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 19 Downloadable Samples
- Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
Elevated levels of androgen receptor (AR) in prostate cancer confer resistance to current antiandrogens and play a causal role in disease progression due to persistent target gene activation. Through pharmacologic and genetic approaches, we show that half of all direct AR target genes, including TMPRSS2, the primary driver of ETS fusion transcripts in 70 percent of human prostate cancers, require histone deacetylase (HDAC) activity for transcriptional activation by AR. Surprisingly, the HDAC3-NCoR complex, which typically functions to repress gene expression by nuclear receptors, is required for AR target gene activation. Prostate cancer cells treated with HDAC inhibitors have reduced AR protein levels, but we show that the mechanism of blockade of AR activity is through failure to assemble a coactivator/RNA polymerase II complex after AR binds to the enhancers of target genes. Failed complex assembly is associated with a phase shift in the cyclical wave of AR recruitment that typically occurs in response to ligand treatment. HDAC inhibitors retain the ability to block AR activity in hormone refractory prostate cancer models and therefore merit clinical investigation in this setting. HDAC-regulated AR target genes defined here can serve as biomarkers to ensure sufficient levels of HDAC inhibition.
Publication Title
Histone deacetylases are required for androgen receptor function in hormone-sensitive and castrate-resistant prostate cancer.
Sample Metadata Fields
No sample metadata fields
View Samples- Rattus norvegicus
- 9 Downloadable Samples
- Affymetrix Rat Genome 230 2.0 Array (rat2302)
Description
The mineralocorticoid aldosterone mainly produced by the adrenal gland is essential for life but an abnormal excessive secretion causes severe pathological effects including hypertension and target organ injury in the heart and kidney. The aim of this study was to determine the gene regulatory network triggered by aldosterone secretagogues in a non transformed cell system. Freshly isolated rat adrenal zona glomerulosa cells were stimulated with the two main aldosterone secretagogues, angiotensin II and potassium, for two hours and subjected to whole genome expression studies using multiple biological and bioinformatics tools. Several genes were differentially expressed by Ang II (n=133) or potassium (n=216). Genes belonging to the nucleic acid binding and transcription factor activity categories were significantly enriched. A subset of the most regulated genes were confirmed by real-time RT-PCR and then their expression analyzed in time curve studies. Differentially expressed genes were grouped according to their time-response expression pattern and their promoter regions analyzed for common regulatory transcription factors binding sites. Finally, data mining with gene promoters, transcription factors and literature databases were performed to generate gene interaction networks for either Ang II or potassium. This study provides for the first time a complete study of the genes that are regulated, and the interaction between them, by aldosterone secretagogues in rat adrenal cells. Increasing our knowledge of adrenal physiology and gene regulation in non transformed cell systems would lead us to a better approach for discovery of candidate genes involved pathological conditions of the adrenal cortex.
Publication Title
Gene expression profile in rat adrenal zona glomerulosa cells stimulated with aldosterone secretagogues.
Sample Metadata Fields
No sample metadata fields
View Samples- Bos taurus
- 72 Downloadable Samples
- Illumina Genome Analyzer II
Description
Mycobacterium bovis (M. bovis) and Mycobacterium avium subspecies paratuberculosis (MAP) are important pathogens of cattle, causing bovine tuberculosis and Johne's disease respectively. M. bovis and MAP infect residential macrophages in the lung and intestines respectively and subvert the macrophage biology to create a survival niche. To investigate this interaction we simultaneously studied the transcriptional response of bovine monocyte-derived macrophages to infection with two strains of M. bovis (AF2122/97 and G18) and two strains of MAP (C & L1). Overall design: 120 samples were analysed in total; derived from six biological replicates (i.e. cells isolated from six cattle). Cells were left uninfected (medium only controls) or infected with either a M. bovis strain (AF2122/97 or G18) or a MAP strain (C or L1). Cells were harvested at 2, 6, 24 and 48h post infection.
Publication Title
Variation in the Early Host-Pathogen Interaction of Bovine Macrophages with Divergent Mycobacterium bovis Strains in the United Kingdom.
Sample Metadata Fields
Subject, Time
View Samples