SiRNA off-target effects can be reduced at concentrations that match their individual potency
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE28786 | GEO | 2011/08/01
SECONDARY ACCESSION(S): PRJNA138691
REPOSITORIES: GEO
Similar Datasets
Project description:This study demonstrates that siRNA off-targets (e.g. 3'UTR off-targets), can be significantly reduced when cells are treated with a relatively low dose of siRNA (e.g. 1nM) that is sufficient to effectively silence the intended target. Cells were treated with different concentrations of either unmodified siRNA or modified siRNA that targeted either hexokinase2 or STAT3 (HK2-3581, HK2-4031, HK2-3581M, STAT3-1676, STAT3-1676M). As transfection efficiencies can vary according to the ratio of nucleotide to transfection reagent, each dose was supplemented with non-targeting/negative control siRNA (siGenome2 or Allstars negative control), such that the total RNA concentration was equal across experiments. RNA was purified 48 hours post-transfection using the RNeasy mini kit from Qiagen. Biological replicates were normalized using the RMA method and analyzed using various Bioconductor tools.
2011-07-31 | E-GEOD-28786 | biostudies-arrayexpress
Project description:Small interfering RNAs (siRNAs) are routinely used to reduce mRNA levels for a specific gene with the goal of studying its function. Several studies have demonstrated that siRNAs are not always specific and can have many off-target effects. The 3' UTRs of off-target mRNAs are often enriched in sequences that are complementary to the seed-region of the siRNA. We demonstrate that siRNA off-targets can be significantly reduced when cells are treated with a dose of siRNA that is relatively low (e.g. 1 nM), but sufficient to effectively silence the intended target. The reduction in off-targets was demonstrated for both modified and unmodified siRNAs that targeted either STAT3 or hexokinase II. Low concentrations reduced silencing of transcripts with complementarity to the seed region of the siRNA. Similarly, off-targets that were not complementary to the siRNA were reduced at lower doses, including up-regulated genes that are involved in immune response. Importantly, the unintended induction of caspase activity following treatment with a siRNA that targeted hexokinase II was also shown to be a concentration-dependent off-target effect. We conclude that off-targets and their related phenotypic effects can be reduced for certain siRNA that potently silence their intended target at low concentrations.
| S-EPMC3130022 | biostudies-literature
Project description:A GAPDH siRNA was overexpressed in HeLa cells and microarray expression profiling was performed to experimentally identify the off-targets of this siRNA at the transcriptome level. Among all predicted siRNA off-targets by MirTarget2, the majority were downregulated by at least 10% (i.e. less than 90% remaining gene expression). Moreover, more than one fifth were downregulated by at least 30%. The gene knockdown data is consistent with previous observations that siRNA off-targets are generally silenced at a more moderate level as compared to silencing of the single intended target
2013-10-03 | GSE41924 | GEO
Project description:A GAPDH siRNA was overexpressed in HeLa cells and microarray expression profiling was performed to experimentally identify the off-targets of this siRNA at the transcriptome level. Among all predicted siRNA off-targets by MirTarget2, the majority were downregulated by at least 10% (i.e. less than 90% remaining gene expression). Moreover, more than one fifth were downregulated by at least 30%. The gene knockdown data is consistent with previous observations that siRNA off-targets are generally silenced at a more moderate level as compared to silencing of the single intended target GAPDH siRNA was transfected into HeLa cells, and the unintended off-targets was identified by microarrays 24 hours post transfection.
2013-10-03 | E-GEOD-41924 | biostudies-arrayexpress
Project description:This experiment addressed the question of whether full length Androgen receptor and Androgen Receptor variant ARv567es have similar transciptional activities. The transcriptomes of R1-AD1, a AR full length expressing cell line, are compared in an AR on (1nM DHT) to an AR off (ethanol vehicle) state. R1-D567 was derived from R1-AD1 and modified with TALENs in such a way as to express only AR-V567es. The AR on and off states were induced with a control siRNA (AR on) or a siRNA targeting exon 1 (AR off). R-AD1 was cultured for 24 hours in either base RPMI media with 1nM DHT or ethanol vehichle and RNA extracted. R1-D567 cells were electroporated with control siRNA or siRNA targeting exon 1 of AR and allowed to recover 48 hours and then cultured in base media with 1nM DHT or ethanol for 24 hrs. Each conditon was done in triplicate.
2013-09-01 | E-GEOD-49196 | biostudies-arrayexpress
Project description:In addition to silencing intended target genes, transfected siRNAs regulate numerous unintended transcripts through a mechanism in which the equivalent of a microRNA-like seed region in the siRNA recognizes complementary sequences in transcript 3' UTRs. The ability to limit such off-target effects would substantially facilitate accurate interpretation of RNA interference (RNAi) experiments and thus greatly enhance their value. We tested whether lentivirus-mediated delivery of shRNA is prone to the seed region-based off-target activity prevalent in siRNA experiments. We compared target gene silencing and overall impact on global gene expression caused by multiple 21-mer duplex sequences delivered as both transfected siRNA and lentivirus vector-expressed shRNA. At equivalent levels of target gene silencing, signatures induced by shRNAs were significantly smaller than those induced by cognate siRNAs and arose less frequently from seed region activity. Interestingly, the low level of seed-region based off-target activity exhibited by shRNAs resulted in down-regulation of transcripts that were largely distinct from those regulated by siRNAs. On the basis of these observations, we recommend lentivirus-mediated RNA interference for pathway profiling experiments that measure whole genome transcriptional readouts as well as for large-scale screens when resources for extensive follow up are limited.
2010-06-09 | GSE22209 | GEO
Project description:The in vitro affinity of a compound for its target is an important feature in drug discovery, but what remains is how predictive in vitro properties are of in vivo therapeutic drug exposure. We assessed the relationship between in vitro potency and clinically efficacious concentrations for marketed small molecule drugs (n = 164) and how they may differ depending on therapeutic indication, mode of action, receptor type, target localization, and function. Approximately 70% of compounds had a therapeutic unbound plasma exposure lower than in vitro potency; the median ratio of exposure in relation to in vitro potency was 0.32, and 80% had ratios within the range of 0.007 to 8.7. We identified differences in the in vivo-to-in vitro potency ratio between indications, mode of action, target type, and matrix localization, and whether or not the drugs had active metabolites. The in vitro-assay variability contributions appeared to be the smallest; within the same drug target and mode of action the within-variability was slightly broader; but both were substantially less compared with the overall distribution of ratios. These data suggest that in vitro potency conditions, estimated in vivo potency, required level of receptor occupancy, and target turnover are key components for further understanding the link between clinical drug exposure and in vitro potency.
| S-EPMC7484912 | biostudies-literature
Project description:Identification of RCO targets using ChIP-seq
| PRJEB29759 | ENA
Project description:This experiment addressed the question of whether full length Androgen receptor and Androgen Receptor variant ARv567es have similar transciptional activities. The transcriptomes of R1-AD1, a AR full length expressing cell line, are compared in an AR on (1nM DHT) to an AR off (ethanol vehicle) state. R1-D567 was derived from R1-AD1 and modified with TALENs in such a way as to express only AR-V567es. The AR on and off states were induced with a control siRNA (AR on) or a siRNA targeting exon 1 (AR off).
2013-09-01 | GSE49196 | GEO
Project description:Culture-adapted bone marrow mesenchymal stromal cells (MSCs) deploy paracrine anti-inflammatory and tissue regenerative functionalities that can be harnessed as a living cell pharmaceutical product. Independent of clinical indication, a near majority of human clinical trials administer MSC IV, often with an allogeneic MSC cell product immediately after thawing from cryostorage. Despite hundreds of studies in a wide assortment of inflammatory, degenerative, and acute tissue injury syndromes, human clinical outcomes often fail to mirror promising rigorously conducted preclinical animal studies. Using a mouse model of toxic colitis, we demonstrate that replication fit MSCs harvested in log phase of growth have substantial impact on colitis clinical and pathologic endpoints when delivered subcutaneously or intraperitoneally, whereas the maximum tolerated IV bolus dosing failed to do so. We also demonstrate that heat-inactivated MSCs lose all therapeutic utility and the observation is mirrored by use of viable MSC administered immediately postthaw from cryostorage. Using luciferase transgenic MSC as donor cells, we demonstrate that transient in vivo engraftment is severely compromised when MSCs are dead or thawed and further demonstrate that MSC redosing is feasible in relapsing colitis, but only syngeneic MSCs lead to sustained improvement of clinical endpoints. These data support the notion that pharmaceutical potency of MSC requires viability and functional fitness. Reciprocally, IV administration of thawed MSC products may be biased against positive clinical outcomes for treatment of colitis and that extravascular administration of syngeneic, fit MSCs allows for effect in a recurrent therapy model.
| S-EPMC7218435 | biostudies-literature