Detecting circular RNAs: bioinformatic and experimental challenges

TL;DR: Biogenesis and function of circRNAs are concentrated on, their implications in BCa are summarized, and their potential as diagnostic and therapeutic targets for BCa is discussed.

Abstract: Circular RNAs are a class of stable non-coding RNAs generated through a back-splicing mechanism. They are now recognized as central players in cell function and are no longer considered byproducts of transcription. CircRNAs regulate gene expression at the transcriptional, post-transcriptional, and translational levels by interacting with various molecules. They act as sponges for miRNAs and proteins, molecular scaffolds, and can also be translated into peptides. Although advances in next-generation sequencing and PCR methods have improved their identification and quantification, technical and bioinformatic challenges remain. Increasing evidence shows their involvement in cardiovascular diseases such as heart failure, hypertrophy, fibrosis, and atherosclerosis, with protective or deleterious effects depending on the context. Given their presence in biological fluids and extracellular vesicles, they can be considered promising biomarkers, but their therapeutic applications are still under investigation. Future studies including a better understanding of their mechanisms of action, the development of standardized validation methods, and potential clinical applications (prevention, early diagnosis, personalized therapies) in diseases are still needed. This review provides an updated overview of the knowledge regarding circRNAs and their translational role in health and disease with a particular focus on cardiovascular diseases.

TL;DR: CircRNAs are highly stable non-coding RNAs that regulate gene expression and have potential for use as biomarkers and therapeutic targets. Their unique structure and function make them an active field of research with ongoing challenges in characterization and understanding their regulation.

TL;DR: In this article, the current research status of circRNAs in prostate cancer is briefly reviewed, and the potential therapeutic targets are discussed, considering their critical regulatory roles in the progression of prostate cancer.

TL;DR: It is found that a human circRNA, antisense to the cerebellar degeneration-related protein 1 transcript (CDR1as), is densely bound by microRNA (miRNA) effector complexes and harbours 63 conserved binding sites for the ancient miRNA miR-7.

TL;DR: This study serves as the first functional analysis of a naturally expressed circular RNA, ciRS-7, which contains more than 70 selectively conserved miRNA target sites, and is highly and widely associated with Argonaute proteins in a miR-7-dependent manner.

TL;DR: High-throughput sequencing of libraries prepared from ribosome-depleted RNA with or without digestion with the RNA exonuclease showed that ecircRNAs are abundant, stable, conserved and nonrandom products of RNA splicing that could be involved in control of gene expression.

TL;DR: Evidence that animal circRNAs are generated cotranscriptionally and that their production rate is mainly determined by intronic sequences is provided and it is demonstrated that circularization and splicing compete against each other.