Identification of 5'isomiR in HCC patients.
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE174608 | GEO | 2021/05/19
REPOSITORIES: GEO
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Project description:miRNAs are small noncoding RNA molecules that play an important role in post-transcriptional regulation of gene expression. Length and/or sequence variants of the same miRNA are termed isomiRs. While most isomiRs are functionally redundant compared to their canonical counterparts, so-called 5âisomiRs exhibit a shifted 5â end and therefore a shifted seed sequence resulting in a different target spectrum. However, not much is known about the functional relevance of these isoforms. Analysis of miRNA-seq data from breast cancer cell lines identified six pairs of highly expressed miRNAs and associated 5âisomiRs. Among them, hsa-miR-140-3p was of particular interest because its 5âisomiR showed higher expression compared to the canonical miRNA annotated in miRbase. This miRNA has previously been shown to control stemness of breast cancer cells. MiRNAseq data of breast cancer patients (TCGA dataset) showed that both the canonical hsa-miR-140-3p and its 5âisomiR-140-3p were highly expressed in patients compared to normal breast tissue. In the current work, we present the functional characterization of 5âisomiR-140-3p and the cellular phenotypes associated with its overexpression in MCF10A and MDA-MB-231 cell lines in comparison to the canonical hsa-miR-140-3p. Contrary to the effect of the canonical hsa miR 140-3p, overexpression of the 5âisomiR-140-3p led to a decrease in cell viability. The latter observation was supported by cell cycle analysis, where the 5âisomiR-140-3p but not the hsa-miR-140-3p caused cell cycle arrest in G0/G1-phase. Additionally, 5âismoiR-140-3p overexpression was found to cause a decrease in cell migration in MCF10A cells. We identified three novel direct target genes of the 5â isomiR-140-3p; COL4A1, ITGA6 and MARCKSL1. Finally, we have shown that knocking down these genes partially phenocopied the effects of the 5âisomiR-140-4p overexpression, where COL4A1 and ITGA6 knockdown led to reduced cell viability and cell cycle arrest, while MARCKSL1 knockdown resulted in a decrease in the migratory potential of cells. In summary, this work presents evidence that there is a functional synergy between the canonical hsa-miR-140-3p and the newly identified 5âisomiR-140-3p in suppressing growth and progression of breast cancer by simultaneously targeting genes related to differentiation, proliferation, and migration. With this array, we aimed to address the question which genes are regulated by either of the two forms of the miRNA. Samples were measured in one biological replicate of cells transfected with mimic-ctrl1 and mimic-ctrl2 (Dharmacon) as control samples and two biological replicates of cells transfected with hsa-miR-140-3p and 5'isomiR-140-3p (Exiqon) in 30nM concentration using Lipofectamin 2000 as transfection reagent.
2015-10-31 | E-GEOD-74539 | biostudies-arrayexpress
Project description:miRNAs are small noncoding RNA molecules that play an important role in post-transcriptional regulation of gene expression. Length and/or sequence variants of the same miRNA are termed isomiRs. While most isomiRs are functionally redundant compared to their canonical counterparts, so-called 5’isomiRs exhibit a shifted 5’ end and therefore a shifted seed sequence resulting in a different target spectrum. However, not much is known about the functional relevance of these isoforms. Analysis of miRNA-seq data from breast cancer cell lines identified six pairs of highly expressed miRNAs and associated 5’isomiRs. Among them, hsa-miR-140-3p was of particular interest because its 5’isomiR showed higher expression compared to the canonical miRNA annotated in miRbase. This miRNA has previously been shown to control stemness of breast cancer cells. MiRNAseq data of breast cancer patients (TCGA dataset) showed that both the canonical hsa-miR-140-3p and its 5’isomiR-140-3p were highly expressed in patients compared to normal breast tissue. In the current work, we present the functional characterization of 5’isomiR-140-3p and the cellular phenotypes associated with its overexpression in MCF10A and MDA-MB-231 cell lines in comparison to the canonical hsa-miR-140-3p. Contrary to the effect of the canonical hsa miR 140-3p, overexpression of the 5’isomiR-140-3p led to a decrease in cell viability. The latter observation was supported by cell cycle analysis, where the 5’isomiR-140-3p but not the hsa-miR-140-3p caused cell cycle arrest in G0/G1-phase. Additionally, 5’ismoiR-140-3p overexpression was found to cause a decrease in cell migration in MCF10A cells. We identified three novel direct target genes of the 5’ isomiR-140-3p; COL4A1, ITGA6 and MARCKSL1. Finally, we have shown that knocking down these genes partially phenocopied the effects of the 5’isomiR-140-4p overexpression, where COL4A1 and ITGA6 knockdown led to reduced cell viability and cell cycle arrest, while MARCKSL1 knockdown resulted in a decrease in the migratory potential of cells. In summary, this work presents evidence that there is a functional synergy between the canonical hsa-miR-140-3p and the newly identified 5’isomiR-140-3p in suppressing growth and progression of breast cancer by simultaneously targeting genes related to differentiation, proliferation, and migration. With this array, we aimed to address the question which genes are regulated by either of the two forms of the miRNA.
2015-10-31 | GSE74539 | GEO
Project description:Next generation sequencing has allowed the discovery of miRNA isoforms, termed isomiRs. Some isomiRs are derived from imprecise processing of pre-miRNA precursors, leading to length variants. Additional variability is introduced by non-templated addition of bases at the ends or editing of internal bases, resulting in base differences relative to the template DNA sequence. We hypothesized that some component of the isomiR variation reported so far could be due to systematic technical noise. We have developed the XICRA pipeline to analyze small RNA sequencing data at the miRNA,. We exploited its ability to use single or merged reads to compare miRNA isomiR results derived from paired-end (PE) reads with those from single reads (SR) to address whether detectable sequence differences relative to canonical miRNAs found in isomiRs are true biological variations or the result of errors in sequencing. We have detected non-negligible systematic differences between single and PE data which primarily affect putative internally edited isomiRs, and at a much smaller frequency terminal length changing isomiRs. This is relevant for the identification of true isomiRs in small RNA sequencing datasets. . We conclude that potential artifacts derived from sequencing errors and/or data processing could result in an overestimation of abundance and diversity of miRNA isoforms. Efforts in annotating the isomiRnome should take this into account.
2021-03-24 | GSE155370 | GEO
Project description:miRNA overexpression strategy based on RNA Polymerase (Pol) III mediated expression of short hairpin RNA (shRNA) coding particular miRNA is widely used for miRNA functional studies. For some miRNAs, e.g., encoded in the genome as a part of a polycistronic miRNA cluster, it is most likely the only way for their individual stable overexpression. Here we have revealed that extra \texttt{U} residues (up to five) added Pol III at the 3$'$-end of the transcribed shRNA associated with a shift in the Dicer cleavage position of the shRNA. This results in the undesirable formation of 5$'$-end miRNA isoforms (5$'$-isomiRs), which have a significantly altered seed region compared to the initially encoded canonical hsa-miR-93-5p. The predominant expression of 5$'$-isomiRs without three or four first nucleotides instead of the canonical isoform could be disclosed based on miRNA-Seq analysis. Moreover, mRNA sequencing data showed that the 5$'$-isomiRs of hsa-miR-93-5p presumably regulate their own mRNA targets. Thus, omitting miRNA-Seq analysis may lead to erroneous conclusions regarding revealed mRNA targets and possible molecular mechanisms in which studied miRNA is involved.
2023-08-22 | GSE241301 | GEO
Project description:miRNA overexpression strategy based on RNA Polymerase (Pol) III mediated expression of short hairpin RNA (shRNA) coding particular miRNA is widely used for miRNA functional studies. For some miRNAs, e.g., encoded in the genome as a part of a polycistronic miRNA cluster, it is most likely the only way for their individual stable overexpression. Here we have revealed that extra \texttt{U} residues (up to five) added Pol III at the 3$'$-end of the transcribed shRNA associated with a shift in the Dicer cleavage position of the shRNA. This results in the undesirable formation of 5$'$-end miRNA isoforms (5$'$-isomiRs), which have a significantly altered seed region compared to the initially encoded canonical hsa-miR-93-5p. The predominant expression of 5$'$-isomiRs without three or four first nucleotides instead of the canonical isoform could be disclosed based on miRNA-Seq analysis. Moreover, mRNA sequencing data showed that the 5$'$-isomiRs of hsa-miR-93-5p presumably regulate their own mRNA targets. Thus, omitting miRNA-Seq analysis may lead to erroneous conclusions regarding revealed mRNA targets and possible molecular mechanisms in which studied miRNA is involved.
2023-08-22 | GSE241300 | GEO
Project description:miRNA overexpression strategy based on RNA Polymerase (Pol) III mediated expression of short hairpin RNA (shRNA) coding particular miRNA is widely used for miRNA functional studies. For some miRNAs, e.g., encoded in the genome as a part of a polycistronic miRNA cluster, it is most likely the only way for their individual stable overexpression. Here we have revealed that extra \texttt{U} residues (up to five) added Pol III at the 3$'$-end of the transcribed shRNA associated with a shift in the Dicer cleavage position of the shRNA. This results in the undesirable formation of 5$'$-end miRNA isoforms (5$'$-isomiRs), which have a significantly altered seed region compared to the initially encoded canonical hsa-miR-93-5p. The predominant expression of 5$'$-isomiRs without three or four first nucleotides instead of the canonical isoform could be disclosed based on miRNA-Seq analysis. Moreover, mRNA sequencing data showed that the 5$'$-isomiRs of hsa-miR-93-5p presumably regulate their own mRNA targets. Thus, omitting miRNA-Seq analysis may lead to erroneous conclusions regarding revealed mRNA targets and possible molecular mechanisms in which studied miRNA is involved.
2023-11-17 | GSE247987 | GEO
Project description:miRNA overexpression strategy based on RNA Polymerase (Pol) III mediated expression of short hairpin RNA (shRNA) coding particular miRNA is widely used for miRNA functional studies. For some miRNAs, e.g., encoded in the genome as a part of a polycistronic miRNA cluster, it is most likely the only way for their individual stable overexpression. Here we have revealed that extra \texttt{U} residues (up to five) added Pol III at the 3$'$-end of the transcribed shRNA associated with a shift in the Dicer cleavage position of the shRNA. This results in the undesirable formation of 5$'$-end miRNA isoforms (5$'$-isomiRs), which have a significantly altered seed region compared to the initially encoded canonical hsa-miR-93-5p. The predominant expression of 5$'$-isomiRs without three or four first nucleotides instead of the canonical isoform could be disclosed based on miRNA-Seq analysis. Moreover, mRNA sequencing data showed that the 5$'$-isomiRs of hsa-miR-93-5p presumably regulate their own mRNA targets. Thus, omitting miRNA-Seq analysis may lead to erroneous conclusions regarding revealed mRNA targets and possible molecular mechanisms in which studied miRNA is involved.
2024-04-17 | GSE264166 | GEO
Project description:Using miRDeep2 and a custom NGS data analysis workflow to annotate and quantify isomiRs in normal and neoplastic colorectal tissues.
2018-05-10 | GSE89974 | GEO
Project description:MicroRNAs (miRNA) have alternative forms known as isomiRs, which differ from each other by a few nucleotides. Next generation sequencing platforms facilitate identification of these isomiRs and recent discoveries regarding their functional importance have increased our understandings of the regulatory complexities of the microRNAome. Observed changes in the miRNA profiles in mosquitoes infected with flaviviruses have implicated small RNAs in the interactions between viruses and their vectors. Here we analysed the isomiR profiles of both uninfected and infected blood fed Aedes aegypti mosquitoes with a major human pathogen, Dengue virus at two time points post-infection. We found noticeable changes to the isomiR expression profile in response to infection and aging. Data analysis revealed a distinct bias towards isomiR production in the mature miRNA as opposed to the star strand. Furthermore, we noticed that only in 40% of Ae. aegypti miRNAs, the most abundant reads for each particular miRNA match the exact sequence reported in the miRbase. The isomiR expression variations between an Ae. aegypti embryonic cell line (Aag2) and whole mosquitoes demonstrated a tissue-specific pattern of isomiR production. Our results illustrated a bias for certain types of isomiRs for each miRNA. The findings presented in this study also provide evidence that isomiR production is not a random phenomenon and may be important in DENV colonisation of its vector. Examination of isomiR production rate in DENV infected and non infected mosquitoes
2015-11-05 | E-GEOD-59516 | biostudies-arrayexpress
Project description:MicroRNAs (miRNAs) are single-stranded non-coding RNAs that negatively regulate target gene expression through mRNA cleavage or translational repression. There is mounting evidence that they play critical roles in heart disease. The expression of known miRNAs in the heart has been studied at length by microarray and quantitative PCR but it is becoming evident that microRNA isoforms (isomiRs) are potentially physiologically important. It is well known that left ventricular (patho)physiology is influenced by transmural heterogeneity of cardiomyocyte phenotype, and this likely reflects underlying heterogeneity of gene expression. Given the significant role of miRNAs in regulating gene expression, knowledge of how the miRNA profile varies across the ventricular wall will be crucial to better understand the mechanisms governing transmural physiological heterogeneity. To determinine miRNA/isomiR expression profiles in the rat heart we investigated tissue from different locations across the left ventricular wall using deep sequencing. We detected significant quantities of 145 known rat miRNAs and 68 potential novel orthologs of known miRNAs, in mature, mature* and isomiR formation. Many isomiRs were detected at a higher frequency than their canonical sequence in miRBase and have different predicted targets. The most common miR-133a isomiR was more effective at targeting a construct containing a sequence from the gelsolin gene than was canonical miR-133a, as determined by dual-fluorescence assay. We identified a novel rat miR-1 homolog from a second miR-1 gene; and a novel rat miRNA similar to miR-676. We also cloned and sequenced the rat miR-486 gene which is not in miRBase (v18). Signalling pathways predicted to be targeted by the most highly detected miRNAs include Ubiquitin-mediated Proteolysis, Mitogen-Activated Protein Kinase, Regulation of Actin Cytoskeleton, Wnt signalling, Calcium Signalling, Gap junctions and Arrhythmogenic Right Ventricular Cardiomyopathy. Most miRNAs are not expressed in a gradient across the ventricular wall, with exceptions including miR-10b, miR-21, miR-99b and miR-486.
2014-03-28 | GSE56300 | GEO