A computational algorithm to predict shRNA potency
Ontology highlight
ABSTRACT:
ORGANISM(S): Gallus gallus
SUBMITTER: Simon Knott
PROVIDER: E-GEOD-62189 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Purpose: Generate a large, high quality database of paired shRNA efficacy/sequence datapoints. Methods:Twelve shRNAs for each Refseq annotated human gene were selected based on the DSIR algorithm. Twelve batches of ~22K shRNAs (corresponding to 12 agilent chips) were then assessed for efficacy via the sensor method outlined in Fellmann et al, Mol Cell, 2011. Conclusions: Neighboring nucleotide combinations are best at predicting shRNA efficacy.
2014-11-24 | E-GEOD-62183 | biostudies-arrayexpress
Project description:shRNAs selected with the shERWOOD algorithm were converted to have a U at the 5' end of their guide. When endogenous 1U shRNAs were compared to artificial shRNA via the sensor algorithm, the endogenous shRNAs were found to be more efficacious. Purpose: Structural studies have hinted that the 5' end of shRNA guides is engulfed in the RISC complex. It has also been reported that shRNAs with a 5' U are more efficacious than those with other 5' caps. We wished to determine whether replacement of shRNA guide 5' nucleotides with a U, regardless of the corresponding target base, would increase their efficacy. Method: For each gene in the "druggable genome" 10 shRNAs were selected with the shERWOOD algorithm. In each case the score was assessed as if the guide had a 5' U. Sensor constructs were designed pairing 1U-guide shRNAs with their endogenous target. shRNAs were assessed for efficacy via the shRNA sensor assay (Fellmann et al. Mol Cell 2011). Results: shRNAs with artificial 5' Us were found to be less efficacious than those with an endogenous 5' U,
2014-11-24 | E-GEOD-62186 | biostudies-arrayexpress
Project description:Two shRNAs were placed into expression vectors harboring mir30 microRNA scaffold and an optimized scaffold where the artificial restriction sights in mir30 have been removed. After infection and selection shRNA processing was assessed by small-RNA cloning. For both shRNAs, placement into the optimized scaffold resulted in a ~two-fold increase in processing (based on smallRNA levels). Purpose: Others have reported that the EcoRI site that was introduced to the mir30 scaffold results in decreased smallRNA processing and hence reduced target knockdown. We've developed an alternative scaffold (termed ultramir) where this site is removed. smallRNA cloning was used to determine if the movement of this sight resulted in an increase in shRNA processing. Method: Two shRNAs (one targeting Renilla Luciferase and one targeting Human RPA3) were cloned into the original mir30 cassette the ultramir cassette. Each of the 4 constructs were infected in duplicate at single copy into cells and the cells seltected unitil infection percentages reached >90% (the shRenilla hairpin was infected into HEK293T cells and the shRPA3 construts into the Gallus gallus cell line ERC. After selection smallRNA cloning was perfromed and the amount of smallRNAs corrresponding to the two shRNAs compared to the endogenous microRNA populatlon. Results: smallRNA levels of the two shRNAs doubled relative to the microRNA population when they were placed into the ultramir scaffold.
2014-11-24 | E-GEOD-62187 | biostudies-arrayexpress
Project description:Sub-genomewide shRNA libraries were constructed using the current RNAi consortium constructs as well as using the DSIR (siRNA algoirthm) and a novel shRNA specific algorithm (shERWOOD). All libraries were placed into mir30 expression vectors. The shERWOOD libraries were also placed in a vector harboring an optimized mir cassette (ultramir). Each library was screened using the pancreatic cell line A385. A concensus set of essential genes identified as the set for which two shRNAs depleted in each of the libries. For these genes, a great percentage of shERWOOD seletected shRNA depleted. In addition the placement of shERWOOD selected constructs into ultramir scaffoled increased the rate of shRNA depletion for essential genes further. Purpose: shRNA screens were carried out using various library construction strategies to identify the strategy that provides the best shRNA screening results. Method: Libraries were constructed using the TRC shRNA set as well as shRNAs identified using the DSIR and shERWOOD algorithms. shRNA libraries were cloned into mir30 expression vectors. shERWOOD shRNAs were also cloned into an expression vector harboring an optimized microRNA scaffold termed ultramir. Each resultant library was screened using the pancreatic cell line A385. Each library was analyzed separately to identify a set of genes where at least two shRNAs depleted. These gene sets were intersected to develop a set of essential genes. Results: The shERWOOD shRNA libraries provided the highest number depleting shRNAs for each essential gene. Further these shRNAs depleted to a greater extent than did the shRNAs from the other libraries. When shERWOOD libraries were placed into the ultramir cassette a greater number of shRNAs per essential gene depleted.
2014-11-24 | E-GEOD-62185 | biostudies-arrayexpress
Project description:Metastasis is the major cause of death in cancer patients, yet the genetic/epigenetic programs that drive metastasis are poorly understood. Here, we report a novel epigenetic reprogramming pathway that is required for breast cancer metastasis. Concerted differential DNA methylation is initiated by activation of the RON receptor tyrosine kinase by its ligand, macrophage stimulating protein (MSP). Through PI3K signaling, RON/MSP promotes expression of the G:T mismatch-specific thymine glycosylase MBD4. RON/MSP and MBD4-dependent aberrant DNA methylation results in misregulation of a specific set of genes. Knockdown of MBD4 reverses methylation at these specific loci, and blocks metastasis. We also show that the MBD4 glycosylase catalytic residue is required for RON/MSP-driven metastasis. Analysis of human breast cancers using a set of specific genes that are regulated by RON/MSP through MBD4-directed aberrant DNA methylation revealed that this epigenetic program is significantly associated with poor clinical outcome. Furthermore, inhibition of Ron kinase activity with a new pharmacological agent prevents activation of the RON/MBD4 pathway and blocks metastasis of patient-derived breast tumor grafts in vivo. Examination of 3 cell types.
2014-01-02 | E-GEOD-52687 | biostudies-arrayexpress
Project description:WWOX expression is lost during tumor progression in many human malignancies including breast cancer. To understand the effects of loss of WWOX expression we analyzed the consequences of its silencing in normal human breast cells (MCF10F). WWOX silencing led to the formation of larger cell colonies, increased cell motility and decreased cell attachment. WWOX silenced cells demonstrated deregulated expression on genes involved in cell cycle, DNA damage response and cell motility. We detected an enrichment of targets activated by the SMAD3 transcription factor. Most notably expression of ANGPTL4, FST, PTHLH and SERPINE1 were all significantly increased upon WWOX silencing. Upregulation of these genes can be reversed by re-expressing WWOX in the previously silenced cells thus suggesting an inverse correlation between WWOX protein expression and SMAD3 transcriptional activity. Importantly, we demonstrate that WWOX physically interacts with SMAD3 protein via WW domain 1, that WWOX expression dramatically decreases SMAD3 occupancy at the ANGPTL4 and SERPINE1 promoters and significantly quenches activation of a TGFM-NM-2 responsive reporter (3TP-LUX). Furthermore, WWOX expression leads to intracellular redistribution of SMAD3 protein levels redirecting protein availability from the nuclear to the cytoplasmic compartment. Interestingly, meta-analysis of gene expression breast cancer datasets indicate that WWOX and ANGPTL4 expression, encoding a secreted protein of key relevance in breast cancer lung metastatic cells, are inversely correlated and the WWOXlo/ANGPTL4hi cluster of tumors are enriched in triple-negative and basal-like sub-types. In summary, we demonstrate that WWOX modulates SMAD3 signaling in breast cells via direct WW-domain binding and potential cytoplasmic sequestration of SMAD3 protein. Since loss of WWOX expression increases with breast cancer progression and it behaves as an inhibitor of SMAD3 transcriptional activity these observations may help explain, at least in part, the paradoxical pro-tumorigenic effects of TGFM-NM-2 signaling in advanced breast cancer. We compared two independent shRNAs: shWWOX-A and shWWOX-B with 3 biological replicates each one, targeting different regions of the WWOX transcript as a means of ruling out any potential off-target effects.
2013-11-28 | E-GEOD-47371 | biostudies-arrayexpress
Project description:H2A.B is a unique histone H2A variant that shares only 40 ~ 50 % sequence identity with canonical H2A. It has only been identified in mammals and has quickly evolved with remarkable sequence diversity among different species. H2A.B is ubiquitously expressed in most cells and tissues. It is mainly deposited in gene body region.The localization of H2A.B is associated with methylated CpG islands in mouse ES cells.H2A.B facilitates transcription elongation to go through methylated CpG islands in the gene bodies. One typical example is that H2A.B regulates transcription elongation at imprinted loci. We used microarray to test the function of H2A.B on gene expression. Mouse ES cells infected with control knockdown(KD) or H2A.B KD virus were treated with G418. ES cells were extracted for RNA and hybridization on Affymetrix microarrays.
2013-12-24 | E-GEOD-48446 | biostudies-arrayexpress
Project description:In vitro expansion of adult human islet M-NM-2 cells is an attractive solution for the shortage of tissue for cell replacement therapy of type 1 diabetes. Using a lineage tracing approach, we have demonstrated that M-NM-2-cell-derived (BCD) cells rapidly dedifferentiate in culture and can proliferate for up to 16 population doublings. Dedifferentiation is associated with changes resembling epithelial-mesenchymal transition (EMT). The WNT pathway has been shown to induce EMT and plays key roles in regulating replication and differentiation in many cell types. Here we show that BCD cell dedifferentiation is associated with M-NM-2-catenin translocation into the nucleus and activation of the WNT pathway. Inhibition of M-NM-2-catenin expression in expanded BCD cells using short hairpin RNA resulted in growth arrest, mesenchymal-epithelial transition, and redifferentiation, as judged by activation of M-NM-2-cell gene expression. Furthermore, inhibition of M-NM-2-catenin expression synergized with redifferentiation induced by a combination of soluble factors, as judged by an increase in the number of C-peptide-positive cells. Simultaneous inhibition of the WNT and NOTCH pathways also resulted in a synergistic effect on redifferentiation. These findings, which were reproducible in cells derived from multiple human donors, suggest that inhibition of the WNT pathway may contribute to a therapeutically applicable way for generation of functional insulin-producing cells following ex-vivo expansion. Gene expression was studied for beta-cells (4 donors). Dedifferentiation was induced by inhibition of M-NM-2-catenin expression using shRNA. The experiment was performed in 4 batches (see the 'Date' characteristic in the Sample records).
2014-08-27 | E-GEOD-60803 | biostudies-arrayexpress
Project description:shRNAs were assessed for off-target effects by comparing the gene expression profiles of cells that they had been infected into. shRNAs designed with the shERWOOD algorithm and house in the ultramir microRNA scafold were found to have very little off targeting. Purpose: A major detriment to RNAi is off-targeting. We wished to assess the level of off targeting of microRNA (ultramiR) housed shERWOOD shRNAs as compared to similar shRNAs in the TRC collection. Methods: 5 shRNAs targeting each of two genes were infected into the 4T1 cell line. For each gene one shRNA was selected from the TRC collection and one based on the shERWOOD algorithm. For each gene, the exrpession profiles of the corresponding shRNA infected cells were compared using RNAseq. Conclusions: Highly similar profiles were observed between shERWOOD selected shRNAs. TRC shRNAs produced profiles indicative of off-targeting.
2014-11-24 | E-GEOD-62184 | biostudies-arrayexpress
Project description:RUNX1 is a transcription factor functioning both as an oncogene and a tumor suppressor in breast cancer. RUNX1 alters chromatin structure in cooperation with chromatin modifier and remodeling enzymes. In this study, we examined the relationship between RUNX1-mediated transcription and genome organization. We characterized genome-wide RUNX1 localization and performed RNA-seq and Hi-C in RUNX1-depleted and control MCF-7 breast cancer cells. RNA-seq analysis showed that RUNX1 depletion led to up-regulation of genes associated with chromatin structure and down-regulation of genes related to extracellular matrix biology, as well as NEAT1 and MALAT1 lncRNAs. Our ChIP-Seq analysis supports a prominent role for RUNX1 in transcriptional activation. About 30% of all RUNX1 binding sites were intergenic, indicating diverse roles in promoter and enhancer regulation and suggesting additional functions for RUNX1. Hi-C analysis of RUNX1-depleted cells demonstrated that overall three-dimensional genome organization is largely intact, but indicated enhanced association of RUNX1 near Topologically Associating Domain (TAD) boundaries and alterations in long-range interactions. These results suggest an architectural role for RUNX1 in fine-tuning local interactions rather than in global organization. Our results provide novel insight into RUNX1-mediated perturbations of higher-order genome organization that are functionally linked with RUNX1-dependent compromised gene expression in breast cancer cells. Hi-C and RNA-seq experiments were conducted in MCF-7 shNS and shRUNX1 cells. RUNX1 ChIP-seq was conducted in wildtype MCF-7 cells.
2016-08-23 | E-GEOD-75070 | biostudies-arrayexpress