环状RNA：从生物发生到医学治疗

摘要/Abstract

摘要： 环状RNA（CircRNAs）是一类单链共价闭环RNA，在真核细胞中由反向剪接形成。CircRNAs作为microRNA海绵，蛋白海绵，转录和翻译调节因子，在各种疾病相关的信号传导通路中发挥着重要作用。类似于mRNA和siRNA，CircRNAs作为现代医学新疗法的潜力已经被广泛探索。最近，尤其是在应对新冠肺炎疫情，mRNA疫苗的安全性和预防严重症状的有效性已被证实。但是，mRNA相对短的半衰期限制了其在更广泛的治疗领域当中的应用。相对而言，CircRNAs缺乏外切核酸酶介导的降解所需的游离端，因而显示出更强的体内持久性。此外，溴化氰化学法、RNA或者DNA连接酶法、以及自剪切内含子的核酶法，都可能被优化成为高度有效的体外环化方法。CircRNAs因其生物功能的重要性和技术可行性，正在成为一种极具潜力的治疗方法。本研究将系统阐述CircRNAs生物发生、生物学功能、体外环化及潜在的应用，以期为进一步研究CircRNAs提供借鉴。

关键词: font-size:medium, ">环状RNAs；反向剪接；内部核糖体进入位点；体外环化；RNA疗法

Abstract: Circular RNAs (CircRNAs) are a class of single-stranded covalently closed RNAs derived from back-splicing in eukaryotic cells. CircRNAs play important roles in a variety of disease related signaling pathways as microRNA sponges， protein sponges， transcriptional regulators， and translational regulators. Similar as mRNA and siRNA， the potential of circRNAs as a novel modality of novel medicine has been explored. Recently， mRNA vaccines have been proving safe and effective in preventing serious conditions， especially during the COVID-19 pandemic. However， the relatively short half-life of mRNAs remains as hurdle for their broader therapeutic applications. In the other hand， circRNAs have demonstrated much improved durability in vivo due to lack of free ends necessary for exonuclease-mediated degradation. In addition， several RNA circularization methods， including chemical ligation， enzymatic ligation， and ribozymatic ligation， have been optimized to be highly effective in vitro. Taking together， circRNAs could become a promising therapeutic approach based on important biological functions and technical feasibility. In this study， the biogenesis， biological functions， in vitro cyclization and potential applications of CircRNAs will be reviewed in order to provide reference for further study of CircRNAs.

Key words: font-size:medium, ">CircRNA；Back-splicing；IRES；In vitro circularization；RNA therapeutics

中图分类号:

蒋凯, 周蓉, 曾晶, 高璐. 环状RNA：从生物发生到医学治疗[J]. 中国医药导刊, 2023, 25(1): 21-27.

JIANG Kai, ZHOU Rong, ZENG Jing, GAO Lu. CircRNAs： from Biogenesis to Therapeutic Application[J]. CHINESE JOURNAL OF MEDICINAL GUIDE, 2023, 25(1): 21-27.

参考文献

[1]Qu L， Yi Z， Shen Y， et al. Circular rna vaccines against sars-cov-2 and emerging variants [J]. Cell， 2022，185(10)：1728-1744.e1716.
     [2]Puttaraju M， Been MD. Group i permuted intron-exon (pie) sequences self-splice to produce circular exons [J]. Nucleic Acids Research， 1992，20(20)：5357-5364.
     [3]Sanger HL， Klotz G， Riesner D， et al. Viroids are single-stranded covalently closed circular rna molecules existing as highly base-paired rod-like structures [J]. P Natl Acad Sci USA， 1976，73(11)：3852-3856.
     [4]Hsu MT， Coca-Prados M. Electron microscopic evidence for the circular form of rna in the cytoplasm of eukaryotic cells [J]. Nature， 1979，280(5720)：339-340.
     [5]Capel B， Swain A， Nicolis S， et al. Circular transcripts of the testis-determining gene sry in adult mouse testis [J]. Cell， 1993，73(5)：1019-1030.
     [6]Hansen TB. Improved circrna identification by combining prediction algorithms [J]. Front Cell Dev Biol， 2018，6（20）：PMID：29556495.
     [7]Chen C-Y， Chuang T-J. Comment on “a comprehensive overview and evaluation of circular rna detection tools” [J]. PLoS Comput Biol， 2019，15(5)：e1006158.
     [8]Aghaee-Bakhtiari SH. Online databases and circular rnas [J]. Adv Exp Med Biol， 2018，1087：35-38.
     [9]Aufiero S， Reckman YJ， Pinto YM， et al. Circular rnas open a new chapter in cardiovascular biology [J]. Nat Rev Cardiol， 2019，16(8)：503-514.
     [10]Misir S， Wu N， Yang BB. Specific expression and functions of circular rnas [J]. Cell Death and Differentiation， 2022，29(3)：481-491.
     [11]Salzman J， Chen RE， Olsen MN， et al. Cell-type specific features of circular rna expression [J]. PLoS Genetics， 2013，9(9)：e1003777.
     [12]Kristensen LS， Andersen MS， Stagsted LVW， et al. The biogenesis， biology and characterization of circular rnas [J]. Nature Reviews Genetics， 2019，20(11)：675-691.
     [13]Chen LL. The expanding regulatory mechanisms and cellular functions of circular rnas [J]. Nature Reviews Molecular Cell Biology， 2020，21(8)：475-490.
     [14]Xiao MS， Ai Y， Wilusz JE. Biogenesis and functions of circular rnas come into focus [J]. Trends in Cell Biology， 2020，30(3)：226-240.
     [15]Liu CX， Chen LL. Circular rnas： characterization， cellular roles， and applications [J]. Cell， 2022，185(12)：2016-2034.
     [16]Salmena L， Poliseno L， Tay Y， et al. A cerna hypothesis： the rosetta stone of a hidden rna language? [J]. Cell， 2011，146(3)：353-358.
     [17]Hansen TB， Jensen TI， Clausen BH， et al. Natural rna circles function as efficient microrna sponges [J]. Nature， 2013，495(7441)：384-388.
     [18]Memczak S， Jens M， Elefsinioti A， et al. Circular rnas are a large class of animal rnas with regulatory potency [J]. Nature， 2013，495(7441)：333-338.
     [19]Kleaveland B， Shi CY， Stefano J， et al. A network of noncoding regulatory rnas acts in the mammalian brain [J]. Cell， 2018，174(2)：350-362.e317.
     [20]Piwecka M， Glaar P， Hernandez-Miranda LR， et al. Loss of a mammalian circular rna locus causes mirna deregulation and affects brain function [J]. Science (New York， NY)， 2017，357(6357)：1254.
     [21]Li RC， Ke S， Meng FK， et al. Cirs-7 promotes growth and metastasis of esophageal squamous cell carcinoma via regulation of mir-7/hoxb13 [J]. Cell Death & Disease， 2018，9(8)：838.
     [22]Sang M， Meng L， Sang Y， et al. Circular rna cirs-7 accelerates escc progression through acting as a mir-876-5p sponge to enhance mage-a family expression [J]. Cancer Letters， 2018，426：37-46.
     [23]Geng HH， Li R， Su YM， et al. The circular rna cdr1as promotes myocardial infarction by mediating the regulation of mir-7a on its target genes expression [J]. PLoS One， 2016，11(3)：e0151753.
     [24]Xu H， Guo S， Li W， et al. The circular rna cdr1as， via mir-7 and its targets， regulates insulin transcription and secretion in islet cells [J]. Scientific Reports， 2015，5：12453.
     [25]Enuka Y， Lauriola M， Feldman ME， et al. Circular rnas are long-lived and display only minimal early alterations in response to a growth factor [J]. Nucleic Acids Research， 2016，44(3)：1370-1383.
     [26]Guo JU， Agarwal V， Guo H， et al. Expanded identification and characterization of mammalian circular rnas [J]. Genome Biology， 2014，15(7)：409.
     [27]Denzler R， Agarwal V， Stefano J， et al. Assessing the cerna hypothesis with quantitative measurements of mirna and target abundance [J]. Molecular Cell， 2014，54(5)：766-776.
     [28]Bosson AD， Zamudio JR， Sharp PA. Endogenous mirna and target concentrations determine susceptibility to potential cerna competition [J]. Molecular Cell， 2014，56(3)：347-359.
     [29]Du WW， Yang W， Liu E， et al. Foxo3 circular rna retards cell cycle progression via forming ternary complexes with p21 and cdk2 [J]. Nucleic Acids Research， 2016，44(6)：2846-2858.
     [30]Du WW， Yang W， Chen Y， et al. Foxo3 circular rna promotes cardiac senescence by modulating multiple factors associated with stress and senescence responses [J]. European Heart Journal， 2017，38(18)：1402-1412.
     [31]Haque S， Ames RM， Moore K， et al. Circrnas expressed in human peripheral blood are associated with human aging phenotypes， cellular senescence and mouse lifespan [J]. Gero Science， 2020，42(1)：183-199.
     [32]Du WW， Fang L， Yang W， et al. Induction of tumor apoptosis through a circular rna enhancing foxo3 activity [J]. Cell Death and Differentiation， 2017，24(2)：357-370.
     [33]Ashwal-Fluss R， Meyer M， Pamudurti NR， et al. Circrna biogenesis competes with pre-mrna splicing [J]. Molecular Cell， 2014，56(1)：55-66.
     [34]Burd CE， Jeck WR， Liu Y， et al. Expression of linear and novel circular forms of an ink4/arf-associated non-coding rna correlates with atherosclerosis risk [J]. PLoS Genetics， 2010，6(12)：e1001233.
     [35]Holdt LM， Stahringer A， Sass K， et al. Circular non-coding rna anril modulates ribosomal rna maturation and atherosclerosis in humans [J]. Nature Communications， 2016，7：12429.
     [36]Wu N， Yuan Z， Du KY， et al. Translation of yes-associated protein (yap) was antagonized by its circular rna via suppressing the assembly of the translation initiation machinery [J]. Cell Death and Differentiation， 2019，26(12)：2758-2773.
     [37]Chen RX， Chen X， Xia LP， et al. N(6)-methyladenosine modification of circnsun2 facilitates cytoplasmic export and stabilizes hmga2 to promote colorectal liver metastasis [J]. Nature Communications， 2019，10(1)：4695.
     [38]Barbagallo D， Caponnetto A， Cirnigliaro M， et al. Circsmarca5 inhibits migration of glioblastoma multiforme cells by regulating a molecular axis involving splicing factors srsf1/srsf3/ptb [J]. International Journal of Molecular Sciences， 2018，19(2)：480.
     [39]Cheung HC， Hai T， Zhu W， et al. Splicing factors ptbp1 and ptbp2 promote proliferation and migration of glioma cell lines [J]. Brain ： A Journal of Neurology， 2009，132(Pt 8)：2277-2288.
     [40]Pamudurti NR， Bartok O， Jens M， et al. Translation of circrnas [J]. Molecular Cell， 2017，66(1)：9-21.e27.
     [41]Wang Y， Wang Z. Efficient backsplicing produces translatable circular mrnas [J]. RNA (New York， NY)， 2015，21(2)：172-179.
     [42]Legnini I， Di Timoteo G， Rossi F， et al. Circ-znf609 is a circular rna that can be translated and functions in myogenesis [J]. Molecular Cell， 2017，66(1)：22-37.e29.
     [43]Chen CY， Sarnow P. Initiation of protein synthesis by the eukaryotic translational apparatus on circular rnas [J]. Science (New York， NY)， 1995，268(5209)：415-417.
     [44]Yang Y， Fan X， Mao M， et al. Extensive translation of circular rnas driven by n(6)-methyladenosine [J]. Cell Research， 2017，27(5)：626-641.
     [45]Wesselhoeft RA， Kowalski PS， Anderson DG. Engineering circular rna for potent and stable translation in eukaryotic cells [J]. Nature Communications， 2018，9(1)：2629.
     [46]Pelletier J， Sonenberg N. Internal initiation of translation of eukaryotic mrna directed by a sequence derived from poliovirus rna [J]. Nature， 1988，334(6180)：320-325.
     [47]Jaafar ZA， Kieft JS. Viral rna structure-based strategies to manipulate translation [J]. Nature Reviews Microbiology， 2019，17(2)：110-123.
     [48]Gross JD， Moerke NJ， von der Haar T， et al. Ribosome loading onto the mrna cap is driven by conformational coupling between eif4g and eif4e [J]. Cell， 2003，115(6)：739-750.
     [49]Chen CK， Cheng R， Demeter J， et al. Structured elements drive extensive circular rna translation [J]. Molecular Cell， 2021，81(20)：4300-4318.e4313.
     [50]Godet AC， David F， Hantelys F， et al. Ires trans-acting factors， key actors of the stress response [J]. International Journal of Molecular Sciences， 2019，20(4)：924.
     [51]Chen R， Wang SK， Belk JA， et al. Engineering circular rna for enhanced protein production [J]. Nature Biotechnology， 2022.
     [52]Chen X， Yang T， Wang W， et al. Circular rnas in immune responses and immune diseases [J]. Theranostics， 2019，9(2)：588-607.
     [53]Carriero S， Damha MJ. Template-mediated synthesis of lariat rna and DNA [J]. J Org Chem， 2003，68(22)：8328-8338.
     [54]Chen X， Lu Y. Circular rna： biosynthesis [J]. Front Bioeng Biotechnol， 2021，9：787881.
     [55]Puttaraju M， Been MD. Circular ribozymes generated in escherichia coli using group i self-splicing permuted intron-exon sequences [J]. The Journal of Biological Chemistry， 1996，271(42)：26081-26087.
     [56]Jarrell KA. Inverse splicing of a group ii intron [J]. P Natl Acad Sci USA， 1993，90(18)：8624-8627.
     [57]Petkovic S， Müller S. Rna self-processing： formation of cyclic species and concatemers from a small engineered rna [J]. FEBS Letters， 2013，587(15)：2435-2440.
     [58]Li H， Peng K， Yang K， et al. Circular rna cancer vaccines drive immunity in hard-to-treat malignancies[J]. Theranostics， 2022，12(14)：6422-6436.

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