Screening radiation-differentially expressed circular RNAs and establishing dose classification models in the human lymphoblastoid cell line AHH-1
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE218844 | GEO | 2024/11/01
REPOSITORIES: GEO
Similar Datasets
Project description:The recent reports of two circular RNAs (circRNAs) with strong potential to act as microRNA (miRNA) sponges suggest that circRNAs might play important roles in regulating gene expression. However, the global properties of circRNAs are not well understood. We developed a computational pipeline to identify circRNAs and quantify their relative abundance from RNA-seq data. Applying this pipeline to a large set of non-poly(A)-selected RNA-seq data from the ENCODE project, we annotated 7,112 human circRNAs that were estimated to comprise at least 10% of the transcripts accumulating from their loci. Most circRNAs are expressed in only a few cell types and at low abundance, but they are no more cell-type–specific than are mRNAs with similar overall expression levels. Although most circRNAs overlap protein-coding sequences, ribosome profiling provides no evidence for their translation. We also annotated 635 mouse circRNAs, and although 20% of them are orthologous to human circRNAs, the sequence conservation of these circRNA orthologs is no higher than that of their flanking linear exons. The previously proposed miR-7 sponge, CDR1as, is one of only two circRNAs with more miRNA sites than expected by chance, with the next best miRNA-sponge candidate deriving from a primate-specific zinc-finger gene, ZNF91. These results provide a new framework for future investigation of this intriguing topological isoform while raising doubts regarding a biological function of most circRNAs. Examination of 9 samples in 1 cell type Note: The ENCODE data we used are under GEO SuperSeries GSE26284 (all samples labeled "_cell_total"). But they were not used in the processing of the U2OS data.
2014-07-08 | E-GEOD-51584 | biostudies-arrayexpress
Project description:Circular RNAs (circRNAs) are widespread circular forms of non-coding RNAs with largely unknown function. Because stimulation of mammary cells with the epidermal growth factor (EGF) leads to dynamic changes in the abundance of both coding and non-coding RNA molecules, and culminates in the acquisition of a robust migratory phenotype, this cellular model might disclose functions of circRNAs. Here we show that circRNAs of EGF-stimulated mammary cells are stably expressed, while mRNAs and micro-RNAs change within minutes. In general, the circRNAs we detected are relatively long-lived and weakly expressed. Interestingly, they are almost ubiquitously co-expressed with the corresponding linear transcripts, and the respective, shared promoter regions are more active compared to genes producing linear isoforms only. These findings imply that altered abundance of circRNAs, unlike changes in the levels of other RNAs, might not play critical roles in signaling cascades and downstream transcriptional networks that rapidly commit cells to specific outcomes. Detection of circRNAs from RNA-Seq â triplicate
2015-12-17 | E-GEOD-71195 | biostudies-arrayexpress
Project description:The study aimed to identify circular RNAs (circRNAs) commonly back-spliced to intronic region of different sets of endothelial cells (human cardiac microvascular endothelial cells (HCMEC), human aortic endothelial cells (HAoEC), human umbilical vein endothelial cells (HUVECs)) and to evaluate their overall expression and their expression compared to their respective host gene. Identified circRNAs were quality controlled by their detection in an additional exonuclease RNase R treated RNA-Seq dataset performed with RNA of HUVECs. CircRNAs were compared for overlapping detection between datasets and filtered by annotation for circRNAs back-spliced to intronic regions. Common endothelial intronic circRNAs candidates were compared to respective murine circRNAs stored in the circATLAS database. The prime candidate cZNF292 was functionally characterized in vivo and in vitro.
2023-11-30 | E-MTAB-11171 | biostudies-arrayexpress
Project description:Circular RNAs (circRNAs) are widespread circular forms of non-coding RNAs with largely unknown function. Because stimulation of mammary cells with the epidermal growth factor (EGF) leads to dynamic changes in the abundance of both coding and non-coding RNA molecules, and culminates in the acquisition of a robust migratory phenotype, this cellular model might disclose functions of circRNAs. Here we show that circRNAs of EGF-stimulated mammary cells are stably expressed, while mRNAs and micro-RNAs change within minutes. In general, the circRNAs we detected are relatively long-lived and weakly expressed. Interestingly, they are almost ubiquitously co-expressed with the corresponding linear transcripts, and the respective, shared promoter regions are more active compared to genes producing linear isoforms only. These findings imply that altered abundance of circRNAs, unlike changes in the levels of other RNAs, might not play critical roles in signaling cascades and downstream transcriptional networks that rapidly commit cells to specific outcomes. Histone 3 Lysine 27 Acetylation â 2 replicates
2015-12-17 | E-GEOD-71196 | biostudies-arrayexpress
Project 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. Sequencing of blood RNA from five healthy individuals (biological replicates) plus technical replicate of one sample and detection of circRNAs.
2015-10-26 | E-GEOD-73570 | biostudies-arrayexpress
Project description:Circular RNAs (circRNAs) are a large class of animal RNAs. To investigate possible circRNA functions, it is important to understand circRNA biogenesis. Besides human Alu repeats, sequence features that promote exon circularization are largely unknown. We experimentally identified new circRNAs in C. elegans. Reverse complementary sequences between introns bracketing circRNAs were significantly enriched compared to linear controls. By scoring the presence of reverse complementary sequences in human introns we predicted and experimentally validated novel circRNAs. We show that introns bracketing circRNAs are highly enriched in RNA editing or hyper-editing events. Knockdown of the double-strand RNA editing ADAR1 enzyme significantly and specifically up-regulated circRNA expression. Together, our data support a model of animal circRNA biogenesis in which competing RNA:RNA interactions of introns form larger structures which promote circularization of embedded exons, while ADAR1 antagonizes circRNA expression by melting stems within these interactions. Thus, we assign a new function to ADAR1. Examination of 12 samples in different stages of C.elegans development.
2015-01-06 | E-GEOD-63823 | biostudies-arrayexpress
Project description:Circular RNAs (circRNAs) in animals are an enigmatic class of RNAs with unknown function. To systematically explore circRNAs, we sequenced and computationally analyzed human, mouse and nematode RNA. We detected thousands of well-expressed, stable circRNAs, with oftentimes tissue/developmental stage specific expression. Sequence analysis suggested important regulatory functions for circRNAs. Indeed, we discovered that human circRNA CDR1as is densely bound by miRNA effector complexes and harbors 63 conserved binding sites for the ancient miRNA miR-7. Further analyses indicated that CDR1as functions to bind miR-7 in neuronal tissues. Human CDR1as expression in zebra fish impaired midbrain development similar to knocking down miR-7, suggesting that CDR1as is a miRNA antagonist with a miRNA binding capacity ten times higher than any other known transcript. Together, our data provide evidence that circRNAs form a large class of post-transcriptional regulators. Numerous circRNAs form by head-to-tail splicing of exons, indicating previously unrecognized regulatory potential of coding sequences. 1 Sample
2013-02-28 | E-GEOD-43572 | biostudies-arrayexpress
Project description:Circular RNAs (circRNAs) in animals are an enigmatic class of RNAs with unknown function. To systematically explore circRNAs, we sequenced and computationally analyzed human, mouse and nematode RNA. We detected thousands of well-expressed, stable circRNAs, with oftentimes tissue/developmental stage specific expression. Sequence analysis suggested important regulatory functions for circRNAs. Indeed, we discovered that human circRNA CDR1as is densely bound by miRNA effector complexes and harbors 63 conserved binding sites for the ancient miRNA miR-7. Further analyses indicated that CDR1as functions to bind miR-7 in neuronal tissues. Human CDR1as expression in zebra fish impaired midbrain development similar to knocking down miR-7, suggesting that CDR1as is a miRNA antagonist with a miRNA binding capacity ten times higher than any other known transcript. Together, our data provide evidence that circRNAs form a large class of post-transcriptional regulators. Numerous circRNAs form by head-to-tail splicing of exons, indicating previously unrecognized regulatory potential of coding sequences. PARCLIP was performed as in Hafner et. al Cell 2010 with HEK293 cell lines stably expressing HIS/FLAG/HA-tagged AGO1 or AGO2. We used 4-thiouridine (4SU) to enhance the crosslink and generated cDNA libraries.
2013-02-28 | E-GEOD-43573 | biostudies-arrayexpress
Project description:Purpose
The landscape of circular RNAs (circRNAs), an important class of non-coding RNAs that regulate gene expression, has never been described in human disorders of sex chromosome aneuploidies. We profiled circRNAs in Turner syndrome females (45,X;TS) and Klinefelter syndrome males (47,XXY; KS) to investigate how circRNAs respond to a missing or an extra X chromosome.
Methods
Samples of blood, muscle and fat were collected from individuals with TS (n = 33) and KS (n = 22) and from male (n = 16) and female (n = 44) controls. CircRNAs were identified using a combination of circRNA identification pipelines (CIRI2, CIRCexplorer2 and circRNA_finder).
Results
Differential expression of circRNAs was observed throughout the genome in TS and KS, in all tissues. The host-genes from which several of these circRNAs were derived, were associated with known phenotypic traits. Furthermore, several differentially expressed circRNAs had the potential to capture micro RNAs that targeted protein-coding genes with altered expression in TS and KS.
Conclusion
Sex chromosome aneuploidies introduce pervasive changes in the circRNA transcriptome, demonstrating that the genomic changes in these syndromes are more complex than hitherto thought. CircRNAs may help explain some of the genomic and phenotypic traits observed in these syndromes.
| EGAS00001006404 | EGA
Project description:Circular RNAs (circRNAs) are an endogenous class of animal RNAs. Despite their abundance, their function and expression in the nervous system are unknown. Therefore, we sequenced RNA from different brain regions, primary neurons, isolated synapses, as well as during neuronal differentiation. Using these and other available data, we discovered and analyzed thousands of neuronal human and mouse circRNAs. circRNAs were extraordinarily enriched in the mammalian brain, well conserved in sequence, often expressed as circRNAs in both human and mouse, and sometimes even detected in Drosophila brains. circRNAs were overall upregulated during neuronal differentiation, highly enriched in synapses, and often differentially expressed compared to their mRNA isoforms. circRNA expression correlated negatively with expression of the RNA-editing enzyme ADAR1. Knockdown of ADAR1 induced elevated circRNA expression. Together, we provide a circRNA brain expression atlas and evidence for important circRNA functions and values as biomarkers. To assess circRNA expression in mammalian brain, we sequenced and analyzed mouse brain regions (hippocampus, cerebellum, prefrontal cortex and olfactory bulb), various neuronal differentiation (mouse P19 and human SH-SY5Y cells) and maturation (mouse cortical neurons) stages, and subcellular compartments in mouse (synaptoneurosomal fraction, cytoplasmic fraction, whole brain lysate).
2015-04-24 | E-GEOD-65926 | biostudies-arrayexpress