Project description:Development of LNA gapmers, antisense oligonucleotides used for efficient inhibition of target RNA expression, is limited by non-target mediated hepatotoxicity issues. In the present study, we investigated hepatic transcription profiles of mice receiving non-toxic and toxic LNA gapmers after a single and repeat administration.
2014-01-08 | GSE53230 | GEO
Project description:LNA Blockers for Improved Amplification Selectivity
Project description:Methods: RNA-sequencing was performed on matched samples obtained across several different gene expression measurement methods including: (a) fresh-frozen (FF) RNA samples by mRNA-seq, Ribo-zero and DSN and (b) FFPE samples by Ribo-zero and DSN. We also assayed the matched samples with Agilent microarray. RNA-seq data was compared on the rRNA-removal efficiency, genome profile, library complexity, coverage uniformity and quantitative cosinstency across protocols and with microarray data. Results: Compared to mRNA-seq, Ribo-zero provides equivalent percentage of rRNA component, genome-based mapped reads, and consistent quantification of transcripts. Moreover, Ribo-zero and DSN protocols achieve concordant transcript profiling in FFPE samples, and provide substantially more information on non-poly(A) RNA, which cannot be captured by mRNA-seq. Therefore, our study provides evidence that RNA-sequencing can generate accurate and reproducible transcript quantification using FFPE tissues. mRNA profile of 11 breast tumors were assayed by Agilent microarray, and by RNA-sequencing on libraries including: (a) fresh-frozen (FF) RNA samples by mRNA-seq, Ribo-zero and DSN and (b) FFPE samples by Ribo-zero and DSN, using Illunia HiSeq2000 2x50bp. RNA-Seq raw data is to be made available through dbGaP (controlled access) due to patient privacy concerns: http://www.ncbi.nlm.nih.gov/gap/?term=phs000676
Project description:Transcriptional profiling of breast cancer cells comparing LNA-control transfected cells with cells transfected with LNA-antimiR-21.We searched for miR-21 targets by systematic screening of mRNA profiling of LNA-antimiR-21 transfected MCF-7 cells and MDA-MB-231 cells.
Project description:Circular RNAs (circRNAs) constitute an abundant class of covalently closed non-coding RNA molecules that are formed by backsplicing from eukaryotic protein-coding genes. Recent studies have shown that circRNAs can act as microRNA or protein decoys as well as transcriptional regulators. However, the functions of most circRNAs are still poorly understood. Because circRNA sequences overlap with their linear parent transcripts, depleting specific circRNAs without affecting host gene expression remains a challenge. Here, we assessed the utility of LNA-modified antisense oligonucleotides (ASOs) to knock down circRNAs for loss-of-function studies. We identified 5807 circRNAs in total RNA sequencing data from 4 liver cancer cell lines and used the back splice junction (BSJ) sequences of 7 validated circRNAs as target sites for designing different LNA-modified ASOs for circRNA knockdown. We found that while most RNase H-dependent gapmer ASOs mediate effective knockdown of their target circRNAs, some gapmers reduce the levels of the linear parent transcript and may also cause degradation of unintended off-targets. The circRNA targeting specificity can be enhanced using design-optimized gapmer ASOs or LNA/DNA mixmer ASOs, which display potent and specific circRNA knockdown with a minimal effect on the host genes or predicted off-targets. In summary, our results demonstrate that LNA-modified ASOs complementary to BSJ sequences mediate robust knockdown of circRNAs in vitro and, thus, represent a useful tool to explore the biological roles of circRNAs in loss-of-function studies in cultured cells and animal models.
Project description:Development of LNA gapmers, antisense oligonucleotides used for efficient inhibition of target RNA expression, is limited by non-target mediated hepatotoxicity issues. In the present study, we investigated hepatic transcription profiles of mice receiving non-toxic and toxic LNA gapmers after a single and repeat administration. To understand the mechanism of LNA gapmer-induced heptotoxicity in mice, we investigated the transcription profiles of liver RNA isolated from mice receiving non-toxic sequence (NTS-1), toxic sequence (TS-2), or severely toxic sequence (HTS-3) of LNA gapmers at 25 mg/kg (dose volume of 10 mL/kg) at 8, 16, or 72 hrs after a single administration (by subcutaneous injection ) using microarray analysis. We also investigated the transcription profiles of liver RNA isolated from mice receiving non-toxic sequence (NTS-1) or toxic sequence (TS-2) of LNA gapmers at 25 mg/kg (dose volume of 10 mL/kg) at 2 weeks after repeated administration (by subcutaneous injection ) using microarray analysis.
Project description:We investigated gene expression signatures in the striatum of wild-type mice injected with a control/scrambeled LNA-oligonucleotide (LNA-SCB) and R6/2 mice injected with LNA-SCB or LNA-CTG. Five mice were used per condition. Each group of mice received two consecutive intrastriatal injections of LNA-CTG or LNA-SCB (0.05 nmols per injection, separated by 3 days) at 11 weeks of age , when motor symptoms appeared in the R6/2 mice. Injection of LNA-CTG resulted in a signifficant attenuation of the R6/2 mice motor defficits, as early as one week after administration (12 weeks of age) and persisted for at least 4 additional weeks (15 weeks of age). Overal gene expression in each group was evaluated short before motor improvement was observed (5 days post-injection), to detect gene expression changes and signalling pathway alterations underlying the benefficial effects. Gene expression was assessed with Agilent SurePrint G3 Mouse GE 8 × 60K Microarray. Target genes were validated using real-time quantitative PCR.
Project description:Transcriptional profiling of breast cancer cells comparing LNA-control transfected cells with cells transfected with LNA-antimiR-21.We searched for miR-21 targets by systematic screening of mRNA profiling of LNA-antimiR-21 transfected MCF-7 cells and MDA-MB-231 cells. Two-condition experiment, LNA-antimiR-21 Transfected vs. LNA-control Transfected MCF-7 cells. One replicate per array.
Project description:Antagonism of microRNA-122 in mice by systemically administered LNA-antimiR leads to up-regulation of a large set of predicted target mRNAs in the liver MicroRNA-122 (miR-122) is an abundant liver-specific miRNA, implicated in fatty acid and cholesterol metabolism as well as hepatitis C viral replication. Here, we report that a systemically administered 16-nt, unconjugated LNA (locked nucleic acid)-antimiR oligonucleotide complementary to the 5' end of miR-122 leads to specific, dose-dependent silencing of miR-122 and shows no hepatotoxicity in mice. Antagonism of miR-122 is due to formation of stable heteroduplexes between the LNA-antimiR and miR-122 as detected by northern analysis. Fluorescence in situ hybridization demonstrated uptake of the LNA-antimiR in mouse liver cells, which was accompanied by markedly reduced hybridization signals for mature miR-122 in treated mice. Functional antagonism of miR-122 was inferred from a low cholesterol phenotype and de-repression within 24 h of 199 liver mRNAs showing significant enrichment for miR-122 seed matches in their 3' UTRs. Expression profiling extended to 3 weeks after the last LNA-antimiR dose revealed that most of the changes in liver gene expression were normalized to saline control levels coinciding with normalized miR-122 and plasma cholesterol levels. Combined, these data suggest that miRNA antagonists comprised of LNA are valuable tools for identifying miRNA targets in vivo and for studying the biological role of miRNAs and miRNA-associated gene-regulatory networks in a physiological context. Keywords: compound treatment
Project description:These experiments were designed to quantify depletion of rRNA sequencing reads from bacterial RNA-seq libraries and verify that mRNA sequencing reads were not altered. Specifically, we tested an rRNA depletion method using custom-designed biotinylated oligonucleotides and compared these results to undepleted (total RNA) libraries and libraries made with the previously-available Ribo-Zero kit (Illumina).