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GSE37645
Homo sapiens
18 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Pancreatic ductal adenocarcinoma (PDAC) is a nearly uniformly lethal malignancy, with most patients facing an adverse clinical outcome. Given the pivotal role of aberrant Notch signaling in the initiation and progression of PDAC, we investigated the effect of MRK-003, a potent and selective -secretase inhibitor, in preclinical PDAC models. We used a panel of human PDAC cell lines, as well as patient-derived PDAC xenografts, to determine whether pharmacological targeting of the Notch pathway could inhibit pancreatic tumor growth and potentiate gemcitabine sensitivity. In vitro, MRK-003 treatment downregulated the canonical Notch target gene Hes-1, significantly inhibited anchorage independent growth, and reduced the subset of CD44+CD24+ and aldehyde dehydrogenase (ALDH)+ cells that have been attributed with tumor initiating capacity. Ex vivo pretreatment of PDAC cells with MRK-003 in culture significantly inhibited the subsequent engraftment in immunocompromised mice. In vivo, MRK-003 monotherapy significantly blocked tumor growth in 5 of 9 (56%) patient-derived PDAC xenografts. Moreover, a combination of MRK-003 and gemcitabine showed enhanced antitumor effects compared to gemcitabine alone in 4 of 9 (44%) PDAC xenografts. Baseline gene expression analysis of the treated xenografts indicated that upregulation of nuclear factor kappa B (NFB) pathway components was associated with the sensitivity to single MRK-003, while upregulation in B-cell receptor (BCR) signaling and nuclear factor erythroid-derived 2-like 2 (NRF2) pathway correlated with response to the combination of MRK-003 with gemcitabine. The preclinical findings presented here provide further rationale for small molecule inhibition of Notch signaling as a therapeutic strategy in PDAC.
Publication Title
The gamma secretase inhibitor MRK-003 attenuates pancreatic cancer growth in preclinical models.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 36 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Tumors from pancreatic cancer specimens obtained at surgery were used for efficacy testing and biologic analysis
Publication Title
Coordinated epidermal growth factor receptor pathway gene overexpression predicts epidermal growth factor receptor inhibitor sensitivity in pancreatic cancer.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 2 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Using a novel class of chemically-engineered oligonucleotides, termed "antagomirs", we studied the biological significance of silencing miR-122 in the liver of mice at the mRNA level
Publication Title
Silencing of microRNAs in vivo with 'antagomirs'.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 6 Downloadable Samples
IlluminaHiSeq2000
Description
Covalently closed circular RNA molecules (circRNAs) have recently emerged as a class of RNA isoforms with widespread and tissue specific expression across animals, oftentimes independent of the corresponding linear mRNAs. circRNAs are remarkably stable and sometimes highly expressed molecules. Here, we sequenced RNA in human peripheral whole blood to determine the potential of circRNAs as biomarkers in an easily accessible body fluid. We report the reproducible detection of thousands of circRNAs. Importantly, we observed that hundreds of circRNAs are much higher expressed than corresponding linear mRNAs. Thus, circRNA expression in human blood reveals and quantifies the activity of hundreds of coding genes not accessible by classical mRNA specific assays. Our findings suggest that circRNAs could be used as biomarker molecules in standard clinical blood samples. Overall design: Sequencing of blood RNA from five healthy individuals (biological replicates) plus technical replicate of one sample and detection of circRNAs.
Publication Title
Identification and Characterization of Circular RNAs As a New Class of Putative Biomarkers in Human Blood.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 4 Downloadable Samples
- Illumina Genome Analyzer II
Description
microRNAs (miRNAs) are a large class of small non-coding RNAs which post-transcriptionally regulate the expression of a large fraction of all animal genes and are important in a wide range of biological processes. Recent advances in high-throughput sequencing allow miRNA detection at unprecedented sensitivity, but the computational task of accurately identifying the miRNAs in the background of sequenced RNAs remains challenging. For this purpose we have designed miRDeep2, a substantially improved algorithm which identifies canonical and non-canonical miRNAs such as those derived from transposable elements and informs on high-confidence candidates that are detected in multiple independent samples. Analyzing data from seven animal species representing the major animal clades, miRDeep2 identified miRNAs with an accuracy of 98.6-99.9% and reported hundreds of novel miRNAs. To test the accuracy of miRDeep2, we knocked down the miRNA biogenesis pathway in a human cell line and sequenced small RNAs before and after. The vast majority of the >100 novel miRNAs expressed in this cell line were indeed specifically down-regulated, validating most miRDeep2 predictions. Last, a new miRNA expression profiling routine, low time and memory usage and user-friendly interactive graphic output can make miRDeep2 useful to a wide range of researchers." Overall design: high-throughput sequencing was used to profile small RNA expression in a human MCF-7 cell line before and after Dicer knock-down
Publication Title
miRDeep2 accurately identifies known and hundreds of novel microRNA genes in seven animal clades.
Sample Metadata Fields
Cell line, Subject
View Samples- Homo sapiens
- 6 Downloadable Samples
- IlluminaHiSeq2000
Description
Dicer is a deeply conserved endoribonuclease with key functions in small RNA biogenesis. Here we employed PAR-CLIP/iPAR-CLIP to identify direct Dicer binding sites in the transcriptomes of human cells and human. We found hundreds of novel miRNAs and non-canonical Dicer substrates with high sensitivity. Small RNA production depended on structure of the binding site and is globally biased towards the 5'' arm of hairpins. Unexpectedly, in both species Dicer bound numerous hairpins inside mRNAs without observable small RNA production. Our data revealed ~100 mRNAs of protein coding genes to be targeted in both human and worm. These mRNAs significantly overlapped with the RNAi pathway. We also, unexpectedly, found that mitochondrial transcripts are Dicer targets in both species. We demonstrate functional consequences of Dicer binding by perturbation analysis. Taken together,we provide the first genome-wide catalog of direct Dicer targets. Our results suggest widespread function outside of miRNA biogenesis. Overall design: PAR-CLIP basically as described previously (Hafner et al. 2010).
Publication Title
A variety of dicer substrates in human and C. elegans.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 5 Downloadable Samples
- IlluminaHiSeq2000
Description
The endoribonuclease Dicer is known for its central role in the biogenesis of eukaryotic small RNAs/microRNAs. Despite its importance, Dicer target transcripts have not been directly mapped. Here, we apply biochemical methods to human cells and C. elegans and identify thousands of Dicer binding sites. We find known and hundreds of novel miRNAs with high sensitivity and specificity. We also report structural RNAs, promoter RNAs, and mitochondrial transcripts as Dicer targets. Interestingly, most Dicer binding sites reside on mRNAs/lncRNAs and are not significantly processed into small RNAs. These passive sites typically harbor small, Dicer-bound hairpins within intact transcripts and generally stabilize target expression. We show that passive sites can sequester Dicer and reduce microRNA expression. mRNAs with passive sites were in human and worm significantly associated with processing-body/granule function. Together, we provide the first transcriptome-wide map of Dicer targets and suggest conserved binding modes and functions outside the miRNA pathway. Overall design: Regulatory impact of Dicer binding was assessed by knock down experiments in human HEK293 cells. Drosha knockdown and mock transfections were used as controls. Knockdown was performed with two independent siRNAs each. In total 5 samples.
Publication Title
A variety of dicer substrates in human and C. elegans.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 3 Downloadable Samples
- IlluminaHiSeq2000
Description
Dicer is a deeply conserved endoribonuclease with key functions in small RNA biogenesis. Here we employed PAR-CLIP/iPAR-CLIP to identify direct Dicer binding sites in the transcriptomes of human cells and human. We found hundreds of novel miRNAs and non-canonical Dicer substrates with high sensitivity. Small RNA production depended on structure of the binding site and is globally biased towards the 5'' arm of hairpins. Unexpectedly, in both species Dicer bound numerous hairpins inside mRNAs without observable small RNA production. Our data revealed ~100 mRNAs of protein coding genes to be targeted in both human and worm. These mRNAs significantly overlapped with the RNAi pathway. We also, unexpectedly, found that mitochondrial transcripts are Dicer targets in both species. We demonstrate functional consequences of Dicer binding by perturbation analysis. Taken together,we provide the first genome-wide catalog of direct Dicer targets. Our results suggest widespread function outside of miRNA biogenesis. Overall design: Regulatory impact of Dicer binding was assessed by knock down experiments in human HEK293 cells. Drosha knockdown and mock transfections were used as controls. In total 3 samples.
Publication Title
A variety of dicer substrates in human and C. elegans.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 2 Downloadable Samples
- IlluminaHiSeq2000
Description
Dicer is a deeply conserved endoribonuclease with key functions in small RNA biogenesis. Here we employed PAR-CLIP/iPAR-CLIP to identify direct Dicer binding sites in the transcriptomes of human cells and human. We found hundreds of novel miRNAs and non-canonical Dicer substrates with high sensitivity. Small RNA production depended on structure of the binding site and is globally biased towards the 5'' arm of hairpins. Unexpectedly, in both species Dicer bound numerous hairpins inside mRNAs without observable small RNA production. Our data revealed ~100 mRNAs of protein coding genes to be targeted in both human and worm. These mRNAs significantly overlapped with the RNAi pathway. We also, unexpectedly, found that mitochondrial transcripts are Dicer targets in both species. We demonstrate functional consequences of Dicer binding by perturbation analysis. Taken together,we provide the first genome-wide catalog of direct Dicer targets. Our results suggest widespread function outside of miRNA biogenesis. Overall design: Argonaute loaded small RNAs were extracted from FLAG:AGO2 and FLAG:AGO3 expressing HEK293 cells. Small RNA was purified and length selected (see supplementary methods).
Publication Title
A variety of dicer substrates in human and C. elegans.
Sample Metadata Fields
No sample metadata fields
View Samples- Caenorhabditis elegans
- 4 Downloadable Samples
- Illumina Genome Analyzer II
Description
Animal mRNAs are regulated by hundreds of RNA binding proteins (RBPs). The identification of RBP targets is crucial for understanding their function. A recent method, PAR-CLIP, uses photoreactive nucleosides to crosslink RBPs to target RNAs in cells prior to immunoprecipitation. Here, we establish iPAR-CLIP (in vivo PAR-CLIP) to determine, at nucleotide resolution, transcriptome-wide target sites of GLD-1, a conserved, germline-specific translational repressor in C. elegans. We identified 439 reproducible targets and demonstrate an excellent dynamic range of target detection by iPAR-CLIP. Upon GLD-1 knock-down, protein but not mRNA expression of the 439 targets was specifically and highly significantly upregulated, demonstrating functionality. Finally, we discovered strongly conserved GLD-1 binding sites nearby the start codon of target genes. We propose that GLD-1 interacts with the translation machinery nearby the start codon, a so far unknown mode of gene regulation in eukaryotes. Overall design: Arrested L1 worms were grown in liquid culture supplemented with 2mM 4SU or 6SG. 250,000 worms were sufficient for one iPAR-CLIP experiment. Living adult worms were transferred to NGM plates and crosslinked on ice using a Stratalinker (Stratagene) with customized 365nm UV-lamps (energy setting: 2J/cm2). Worms were lysed on ice by douncing in NP40 lysis buffer (50 mM HEPES-K pH 7.5, 150 mM KCl, 2 mM EDTA, 0.5% (v/v) NP-40, 0.5 mM DTT, protease inhibitor cocktail (Roche)). Cleared lysates were treated with RNase T1 (Fermentas) (final concentration 1U/?l) for 15 min at 22ºC. GLD-1::GFP::FLAG fusion proteins were immunoprecipitated for 1h at 4ºC using anti-FLAG antibody (Sigma, F3165) coupled to Protein G magnetic beads (Invitrogen). For one iPAR-CLIP experiment (1ml cleared lysate obtained from 250,000 worms), 300µl beads and 150µg antibody were used. Immunoprecipitates were treated with RNase T1 (100U/?l) for exactly 12 min at 22 ºC. Subsequently, PAR-CLIP was carried out as described previously (Hafner et al, 2010). cDNA libraries were sequenced on a Genome Analyzer II (Illumina).
Publication Title
In vivo and transcriptome-wide identification of RNA binding protein target sites.
Sample Metadata Fields
Cell line, Subject
View Samples