环状RNA研究的新进展

Research advances in circular RNAs

背景:环状RNA(circ RNA)是一种新型的RNA,与线性RNA不同,它形成共价闭合的连续环,并且在真核转录组中高度表达。它的生物学功能被忽视多年。最近的研究已经在哺乳动物细胞中发现了数千种内源性circRNA。目的:综述circ RNA的形成、性质、功能,以及在疾病中的潜在意义。方法:第一作者应用计算机检索2000年1月至2016年12月Pub Med数据库、中国期刊全文数据库关于circ RNA的文章,英文检索词"CircRNA,mi RNA,function,mechanision";中文检索词"Circ RNA,micro RNA,功能,机制"。对纳入的62篇文献进行分析讨论。结果与结论:(1)CircRNA主要从外显子或内含子序列产生,并且反向互补序列或RNA结合蛋白是circ RNA生物发生所必需的;(2)大多数circRNAs是跨物种保守,对核糖核酸R稳定的和耐,并经常表现出组织/发育阶段特异性表达;(3)最近的研究表明,circ RNAs可以作为微小RNA(mi RNA)海绵体,剪接和转录的调节器和亲代基因表达的修饰;(4)新的证据表明circ RNAs可能在动脉粥样硬化血管疾病,神经系统疾病,朊病毒疾病和癌症中发挥重要作用;在结肠直肠癌中异常表达;并用作一些疾病的诊断或预测性生物标志物;(5)类似于mi RNA和长非编码RNA,circ RNAs成为RNA领域的新研究热点,可以广泛参与生命过程。

BACKGROUND:Unlike linear RNAs,circular RNAs(circRNAs)are a novel type of RNA which can form covalently closed circles and are highly expressed in eukaryotic transcriptomes.In the plenitude of naturally occurring RNAs,circRNAs and their biological role are underestimated for years.Recent studies have discoveredthousands of endogenous circRNAs in mammalian cells.OBJECTIVE:To review the formation,properties,and functions of circRNAs,and their potential significance in diseases.METHODS:A computer-based search for literature in CNKI and PubMed databases published from January2000to December2016was performed using the keywords of“circRNA,miRNA,function,mechanism”in English and Chinese,respectively.Finally,62eligible articles were included for analysis.RESULTS AND CONCLUSION:CircRNAs are largely generated from exonic or intronic sequences,and reverse complementary sequences or RNA-binding proteins are necessary for circRNA biogenesis.A majority of circRNAs that are conserved across specie are stable and resistant to RNaseR,and often exhibit tissue/developmental-stage-specific expression.Recent research has revealed that circRNAs can function as microRNA sponges,regulators of splicing and transcription,and modifiers of parental gene expression.Emerging evidence indicates that circRNAs might play important roles in atherosclerotic vascular diseases,neurological disorders,prion diseases and cancer;exhibit aberrant expression in colorectal cancer;and serve as diagnostic or predictive biomarkers of some diseases.Similar to microRNAs and long noncoding RNAs,circRNAs are arousing general interest in the field of RNA and widely participate in the life process.