Circular RNAs (circRNAs) are covalently closed RNA circles without a 5' cap or 3' tail. Since the landmark discovery of ciRS-7/CDR1as functioning as a miR-7 sponge in 2013, circRNAs have become a hot topic in RNA research. CircRNAs have been found to play active roles in cancer, cardiovascular diseases, neurological disorders, and many other diseases. They can function as microRNA (miRNA) sponges, protein scaffolds, and even translation templates. However, as circRNA research expands, many divergent views have emerged. For example, are most circRNAs competent in serving as miRNA sponges? What kinds of circRNAs are most likely to sponge miRNAs? Apart from sponging miRNAs, what could the functions of most circRNAs be? What are the features of circRNAs that are translatable? Many researchers have claimed that circRNAs are abundant, stable, conserved, and specific molecules, which hold great potential in serving as biomarkers. However, circRNA abundance is variable and some circRNAs are abundant while others are not. In addition, their stability and conservation may vary under different circumstances. Furthermore, it is unclear whether circRNA biogenesis is more likely to be regulated by RNA binding proteins or transcription factors. All of these are open questions that remain to be answered by researchers in this field. Discussing and investigating these questions will advance the understanding of this class of novel molecules and may propel inspiring new ideas for future studies. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA in Disease and Development > RNA in Disease RNA Methods > RNA Analyses in Cells RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.

中文翻译：

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有趣的圈子：循环RNA研究中的冲突和争议。

环状RNA（circRNA）是共价闭合的RNA圈，没有5'帽或3'尾巴。自2013年ciRS-7 / CDR1起miR-7海绵的功能性里程碑式发现以来，circRNA已成为RNA研究的热门话题。已发现CircRNA在癌症，心血管疾病，神经系统疾病和许多其他疾病中起积极作用。它们可以充当microRNA（miRNA）海绵，蛋白质支架甚至翻译模板。然而，随着circRNA研究的扩展，出现了许多分歧的观点。例如，大多数circRNA是否有能力充当miRNA海绵？哪种circRNA最有可能使miRNA变海绵？除了海绵miRNA，大多数circRNA的功能是什么？可翻译的circRNA的特征是什么？许多研究人员声称circRNA丰富，稳定，保守的特定分子，在生物标志物方面具有巨大潜力。但是，circRNA的丰度是可变的，有些circRNA丰富，而另一些则没有。另外，它们的稳定性和保存性可能在不同情况下有所不同。此外，尚不清楚circRNA生物发生是否更可能受到RNA结合蛋白或转录因子的调控。所有这些都是未解决的问题，尚待该领域的研究人员回答。讨论和研究这些问题将增进对这类新型分子的理解，并可能激发鼓舞人心的新思想，以供将来研究之用。本文归类于：调节RNA / RNAi /核糖开关>调节RNA在疾病和发展中的RNA>疾病RNA中的RNA方法>