非编码RNA在肝脏相关疾病中的表达探析

非编码RNA在肝脏相关疾病中的表达探析摘要：非编码RNA（noncodingRNA,ncRNA）是一类不编码蛋白，但在基因的复制、转录、翻译、表达等多个水平对细胞的生长凋零以及疾病的发生与进展过程中发挥重要作用的RNA。在肝脏疾病的发生进展中，病毒性肝炎、酒精性或非酒精性肝病、自身免疫疾性肝病、胆道疾病等慢性肝脏疾病均可缓慢发展为肝纤维化、肝硬化，甚至是肝细胞癌。而在这整个过程中，多种ncRNA参与调节，其表达水平发生明显改变，并且在疾病的发生发展中处于核心调控地位。所以，进一步加强研究ncRNA与肝脏疾病之间的关系，明确其作用机制，有助于我们日后临床中肝脏疾病的精准诊断、治疗与预后。本文综述了长链非编码RNA（longnoncodingRNA;lncRNA）及环状RNA（circularRNA;circRNA）在不同肝脏疾病时的表达情况、作用机制、临床展望等。关键字：非编码RNA、LncRNA、circRNA、肝脏疾病ExpressionofNoncodingRNAinLiverRelatedDiseasesABSTRACTNoncodingRNAs(ncRNAs)areakindofRNAthatdonotencodeproteins,butplayanimportantroleintheprocessofcellgrowthandapoptosis,aswellasintheprocessofdiseaseoccurrenceandprogressionatmultiplelevelssuchasgenereplication,transcription,translationandexpression.Inthedevelopmentofliverdiseases,chronicliverdiseasessuchasviralhepatitis,alcoholicornonalcoholicliverdisease,autoimmuneliverdiseaseandbiliarytractdiseasecandevelopslowlyintohepaticfibrosis,cirrhosisandevenhepatocellularcarcinoma(HCC).However,inthiswholeprocess,varietiesofncRNAparticipateintheregulation,itsexpressionlevelchangessignificantly,anditisinthecoreregulatorypositionintheoccurrenceanddevelopmentofthedisease.Therefore,furtherstudyontherelationshipbetweenncRNAandliverdiseasesanditsmechanismofactionwillbehelpfulfortheaccuratediagnosis,treatmentandprognosisofliverdiseasesinthefuture.Thispaperreviewstheexpression,mechanismandclinicalprospectoflongnoncodingRNA(lncRNA)andcircularRNA(circRNA)indifferentliverdiseases.KEYWORDSnoncodingRNAs;longnoncodingRNA;circularRNA;hepaticdisease1非编码RNA的分类与作用机制1.1非编码RNA的分类非编码RNA（noncodingRNAs,ncRNA）起初被认为是基因组的废弃物，对基因的表达并无实质作用，直到后来随着现代科学技术的进步和人类对医学的艰苦钻研，才逐渐发现，人类基因组中的大部分都被转录成了各种ncRNA。这些RNA由基因组转录而来，但是不编码蛋白，在RNA水平就可行使生物学功能。非编码RNA根据长度可划分为3类：小于50nt；50nt~500nt；大于500nt。根据生物学功能的不同，又可分为结构非编码RNA（structuralncRNAs）和调控非编码RNA（regulatoryncRNAs），结构非编码RNA主要包括rRNA、tRNA、snRNA等，调控非编码RNA主要包括siRNA、lncRNA、环状RNA（circularRNA;circRNA）[[]QuZP,DavidLA.EvolutionaryConservationandFunctionalRolesofncRNA[J].FrontiersinGenetics,2012,3:205-215.，[][]QuZP,DavidLA.EvolutionaryConservationandFunctionalRolesofncRNA[J].FrontiersinGenetics,2012,3:205-215.[]ChrisPP,PeterLO,WolfR.EvolutionandFunctionsofLongNoncodingRNAs[J].Cell,2009,136(4):629-641.1.2非编码RNA的作用机制1.2.1lncRNA：21世纪初，lncRNA由日本学者Okazaki[[]OkazakiY,FurunoM,KasukawaT,etal.Analysisofthemousetranscriptomebasedonfunctionalannotationof60,770full-lengthcDNAs[J].Nature,2002,420(6915):563-573.]最先发现，即一种长度大于200nt的非编码RNA，并认为没有重要的生物学功能。而后Rinn[[]JohnLR,MichaelK,JordonK,etal.FunctionalDemarcationofActiveandSilentChromatinDomainsinHumanHOXLocibyNoncodingRNAs[J].Cell,2007,129(7):1311-1323.]等人于2007年报道了一条功能性长链非编码RNA（HOTAIR），可通过修饰染色质，参与HOX基因的转录。这一重要发现表明lncRNA不再仅仅是编码RNA的垃圾，反而却有很大程度的可能对整个基因的表达起到十分重要的作用。自此之后，lncRNA逐渐成为基因学的研究热点。根据目前的研究，lncRNA的作用机制并不是十分完善，主要的机制有：靶向作用于转录因子、RNA聚合酶等影响基因的转录过程，调节基因的转录和表达；结合PRC1（polycombrepressivecomplex1）、PRC2（polycombrepressivecomplex2）和染色质修饰蛋白，引导染色质修饰复合物发挥改变表观遗传的特异性效应；通过与蛋白质和蛋白复合体直接相互作用作为支架、变构激活剂或抑制剂发挥致癌作用；通过结合miRNA作为竞争性内源RNA（ceRNA）机制发挥海绵吸附作用，进一步调控下游靶基因[[[]OkazakiY,FurunoM,KasukawaT,etal.Analysisofthemousetranscriptomebasedonfunctionalannotationof60,770full-lengthcDNAs[J].Nature,2002,420(6915):563-573.[]JohnLR,MichaelK,JordonK,etal.FunctionalDemarcationofActiveandSilentChromatinDomainsinHumanHOXLocibyNoncodingRNAs[J].Cell,2007,129(7):1311-1323.[]甘园园,何晓琴,徐细明.长链非编码RNA与肝癌的关系及其研究进展[J].中国医药导报,2016,13(31):49-52.[]WangKC,ChangHY.MolecularmechanismsoflongnoncodingRNAs[J].Molecularcell,2011,43(6):904-914.1.2.2circRNA：1976年，Sanger等首次在植物感染的病毒中观察到了共价闭合环状RNA分子[[]SangerHL,KlotzG,RiesnerD,etal.Viroidsaresingle-strandedcovalentlyclosedcircularRNAmoleculesexistingashighlybase-pairedrod-likestructures[J].ProceedingsoftheNationalAcademyofSciencesoftheUnitedStatesofAmerica,1976,73(11):3852-3856.]。但是这些RNA仅仅被当作是异常剪接的产物，并没有引起广泛重视。2012年，Salzman等通过小儿急性淋巴细胞白血病样品的RNA测序数据库，发现了circRNA在人类细胞的普遍表达，基于此数据库发现人体内大约有10万个circRNA[[]SalzmanJ,GawadC,WangPL,etal.CircularRNAsarethepredominanttranscriptisoformfromhundredsofhumangenesindiversecelltypes[J].PloSone,2012,7(2):e30733-e30744.]。人们才开始重新认识并深入研究circRNA。circRNA由于其环状结构的特异性，因此不易被核酸外切酶RNaseR和分支酶降解[[]ZhangY,ZhangXO,ChenT,etal.CircularIntronicLongNoncodingRNAs[J].MolecularCell,2013,51(6):792-806.]，具有更稳定和高度保守的特点[[][]SangerHL,KlotzG,RiesnerD,etal.Viroidsaresingle-strandedcovalentlyclosedcircularRNAmoleculesexistingashighlybase-pairedrod-likestructures[J].ProceedingsoftheNationalAcademyofSciencesoftheUnitedStatesofAmerica,1976,73(11):3852-3856.[]SalzmanJ,GawadC,WangPL,etal.CircularRNAsarethepredominanttranscriptisoformfromhundredsofhumangenesindiversecelltypes[J].PloSone,2012,7(2):e30733-e30744.[]ZhangY,ZhangXO,ChenT,etal.CircularIntronicLongNoncodingRNAs[J].MolecularCell,2013,51(6):792-806.[]StanislasW,StephanN,ThomasS,etal.CharacterizationofcircularRNAsinhuman,mouseandrathearts[J].JournalofMolecularandCellularCardiology,2016,98:103-107.2非编码RNA与病毒性肝炎病毒性肝炎严重威胁人类健康与生活品质，在我国的各类传染病中发病率最高，尤其是乙型肝炎。病毒性肝炎是慢性肝脏炎症、肝纤维化、肝硬化，乃至肝癌的重要因素。非编码RNA在病毒性肝炎的复制、抗病毒方面发挥关键作用，但其作用机制尚需进一步研究。2.1LncRNA与病毒性肝炎Samaloty[[]ElSN,ShabayekMI,GhaitRS,etal.AssessmentoflncRNAGAS5,lncRNAHEIH,lncRNABISPRanditsmRNABST2asseruminnovativenon-invasivebiomarkers:RecentinsightsintoEgyptianpatientswithhepatitisCvirustype4[J].Worldjournalofgastroenterology,2020,26(2):109-265.]等表明，在尚未予以治疗手段的病毒性肝炎患者中，血清LncRNAGAS5和LncRNABISPR上调，而LncRNAHEIH下调，其中GAS5和BISPR与病毒载量以及ALT呈正相关（P<0.001），更有意思的是，HEIH与AFP亦呈显著正相关（P<0.001）。Hu[[]HuP,WilhelmJ,GerresheimGK,etal.Lnc-ITM2C-1andGPR55AreProviralHostFactorsforHepatitisCVirus[J].Viruses,2019,11(6):549-577.]等人证实在HCV感染后早期LncR-8（Lnc-ITM2C-1/LOC151484）上调。并表明LncR-8表达与HCV复制呈正相关，HCV诱导LncR-8表达，而LncR-8通过刺激其邻近基因GPR55的表达间接促进HCV复制。Fan[[]FanJJ,ChengM,ChiXJ,etal.AHumanLongNon-codingRNALncATVPromotesVirusReplicationThroughRestrictingRIG-I-MediatedInnateImmunity[J].Frontiersinimmunology,2019,10:1711-1718.]等人发现LncATV基因敲除显著抑制了丙型病毒肝炎、寨卡病毒、新城疫病毒和仙台病毒等多种RNA病毒的复制，其机制为通过限制RIG-I介导的先天免疫来促进病毒的复制。上述研究提示LncRNA通过影响肝炎病毒的复制进而调控病毒性肝炎的发展，可作为生物诊断分子或治疗分子。而某些LncRNA在病毒性肝炎中的表达尚存在争议,如LncRNA-Dreh，Huang[[]HuangJF,GuoYJ,ZhaoCX,etal.HepatitisBvirusXprotein(HBx)-relatedlongnoncodingRNA(lncRNA)down-regulatedexpressionbyHBx(Dreh)inhibitshepatocellularcarcinomametastasisbytargetingtheintermediatefilamentproteinvimentin[J].Hepatology(Baltimore,Md.),2013,57(5):1882-1892.][]ElSN,ShabayekMI,GhaitRS,etal.AssessmentoflncRNAGAS5,lncRNAHEIH,lncRNABISPRanditsmRNABST2asseruminnovativenon-invasivebiomarkers:RecentinsightsintoEgyptianpatientswithhepatitisCvirustype4[J].Worldjournalofgastroenterology,2020,26(2):109-265.[]HuP,WilhelmJ,GerresheimGK,etal.Lnc-ITM2C-1andGPR55AreProviralHostFactorsforHepatitisCVirus[J].Viruses,2019,11(6):549-577.[]FanJJ,ChengM,ChiXJ,etal.AHumanLongNon-codingRNALncATVPromotesVirusReplicationThroughRestrictingRIG-I-MediatedInnateImmunity[J].Frontiersinimmunology,2019,10:1711-1718.[]HuangJF,GuoYJ,ZhaoCX,etal.HepatitisBvirusXprotein(HBx)-relatedlongnoncodingRNA(lncRNA)down-regulatedexpressionbyHBx(Dreh)inhibitshepatocellularcarcinomametastasisbytargetingtheintermediatefilamentproteinvimentin[J].Hepatology(Baltimore,Md.),2013,57(5):1882-1892.[]潘延凤,秦涛,冯磊,等.ExpressionProfileofAlteredLongNon-codingRNAsinPatientswithHBV-associatedHepatocellularCarcinoma[J].JournalofHuazhongUniversityofScienceandTechnology(MedicalSciences),2013,33(01):96-101.2.2circRNA与病毒性肝炎目前来讲，关于circRNA和病毒性肝炎的研究尚处于匮乏阶段，其研究结果也乏善可陈，但无论是人体自身存在的还是人工外体合成的，circRNA都因其结构的独特性和稳定性，有望为病毒性肝炎的诊疗提供新的方向。3非编码RNA与肝纤维化肝纤维化是由炎症、药物等多种因素引起的肝内结缔组织的异常增生，主要病理表现有肝星状细胞的活化增生和胶原蛋白的沉积，目前临床上尚缺乏有效治疗肝纤维化的措施，而非编码RNA的发现与研究为肝纤维化的治疗指明了另一途径。3.1LncRNA与肝纤维化Zhang[[]ZhangK,HanYW,HuZM,etal.SCARNA10,anuclear-retainedlongnon-codingRNA,promotesliverfibrosisandservesasapotentialbiomarker[J].Theranostics,2019,9(12):3622-3638.]等人发现LncRNASCARNA10在小鼠纤维化肝脏中表达显著上调，并证明SCARNA10通过抑制PRC2与细胞外基质（extracellularmatrix;ECM）和转化生长因子（TGFβ）途径相关基因启动子的结合，在肝纤维化的发生中起到了一种新的TGFβ信号阳性调节因子的作用，促进了肝细胞（hepaticcells;HCs）的凋亡和肝星状细胞（hepaticstellatecell;HSC）的活化，在体内外均促进了肝纤维化。Kong[[]KongYY,HuangTJ,ZhangHY,etal.ThelncRNANEAT1/miR-29b/Atg9aaxisregulatesIGFBPrP1-inducedautophagyandactivationofmousehepaticstellatecells[J].Lifesciences,2019,237:116902-116938.]等人证实Lnc-NEAT1通过NEAT1/miR-29b/Atg9a调控轴参与胰岛素样生长因子结合蛋白相关蛋白1（IGFBPrP1）促进HSC的自噬和活化过程。提示LncRNASCARNA10和Lnc-NEAT1可能是肝纤维化的破坏因子，可通过抑制其表达而延缓纤维化的过程。又有研究表明Lnc-HSER为一种肝细胞特异性表达的LncRNA，在人和小鼠的纤维化肝脏以及发生肝纤维化的小鼠的原发性肝细胞中减少，可通过5AR1-Hippo-YAP途径抑制肝细胞凋亡、通过Notch信号抑制肝细胞的上皮细胞-间充质转化（EMT）过程[[]ZhangK,ZhangMX,YaoQB,etal.Thehepatocyte-specificallyexpressedlnc-HSERalleviateshepaticfibrosisbyinhibitinghepatocyteapoptosisandepithelial-mesenchymaltransition[J].Theranostics,2019,9(25):7566-7582.]。LncRNA-Meg8在活化的肝星状细胞、损伤的肝细胞以及纤维化的肝脏中过度表达，并提出LncRNA-Meg8可能通过抑制Notch途径抑制HSC活化和EMT过程[[]ChenT,LinHJ,ChenX,etal.LncRNAMeg8suppressesactivationofhepaticstellatecellsandepithelial-mesenchymaltransitionofhepatocytesviatheNotchpathway[J].Biochemicalandbiophysicalresearchcommunications,2020,521(4):921-927.]。LncRNAGm5091在酒精性肝纤维化(alcoholichepaticfibrosis;AHF)小鼠HSC中被下调，可能通过吸附miR-27b、miR-23b和miR-24减轻小鼠AHF，且对细胞迁移、ROS含量、IL-1β分泌、[]ZhangK,HanYW,HuZM,etal.SCARNA10,anuclear-retainedlongnon-codingRNA,promotesliverfibrosisandservesasapotentialbiomarker[J].Theranostics,2019,9(12):3622-3638.[]KongYY,HuangTJ,ZhangHY,etal.ThelncRNANEAT1/miR-29b/Atg9aaxisregulatesIGFBPrP1-inducedautophagyandactivationofmousehepaticstellatecells[J].Lifesciences,2019,237:116902-116938.[]ZhangK,ZhangMX,YaoQB,etal.Thehepatocyte-specificallyexpressedlnc-HSERalleviateshepaticfibrosisbyinhibitinghepatocyteapoptosisandepithelial-mesenchymaltransition[J].Theranostics,2019,9(25):7566-7582.[]ChenT,LinHJ,ChenX,etal.LncRNAMeg8suppressesactivationofhepaticstellatecellsandepithelial-mesenchymaltransitionofhepatocytesviatheNotchpathway[J].Biochemicalandbiophysicalresearchcommunications,2020,521(4):921-927.[]ZhouB,YuanWW,LiXP.LncRNAGm5091alleviatesalcoholichepaticfibrosisbyspongingmiR‐27b/23b/24inmice[J].CellBiologyInternational,2018,42(10):1330-1339.H19在肝纤维化中的表达尚存在争议，Yang[[]YangJJ,SheQ,YangY,etal.DNMT1controlsLncRNAH19/ERKsignalpathwayinhepaticstellatecellactivationandfibrosis[J].ToxicologyLetters,2018,295:325-334.]等人发现在活化的HSC和大鼠肝纤维化组织中，LncRNAH19表达降低，并证实H19siRNA处理HSC可增加HSC中p-ERK1/2的表达。而Song[[]SongYF,LiuCE,LiuX,etal.H19promotescholestaticliverfibrosisbypreventingZEB1‐mediatedinhibitionofepithelialcelladhesionmolecule[J].Hepatology,2017,66(4):1183-1196.]等人的研究却表明在肝纤维化小鼠肝组织中LncRNAH19的表达显著上升，其机制可能是，肝LncRNAH19的激活下调肝锌指电子盒结合同源盒1（ZEB1）、[]YangJJ,SheQ,YangY,etal.DNMT1controlsLncRNAH19/ERKsignalpathwayinhepaticstellatecellactivationandfibrosis[J].ToxicologyLetters,2018,295:325-334.[]SongYF,LiuCE,LiuX,etal.H19promotescholestaticliverfibrosisbypreventingZEB1‐mediatedinhibitionofepithelialcelladhesionmolecule[J].Hepatology,2017,66(4):1183-1196.3.2circRNA与肝纤维化Chen[[]ChenYH,YuanBY,ChenGW,etal.CircularRNARSF1promotesinflammatoryandfibroticphenotypesofirradiatedhepaticstellatecellbymodulatingmiR-146a-5p[J].Journalofcellularphysiology,2020,doi:10.1002/jcp.29483.]等发现CircRNA-RSF1（circRSF1）在照射LX2细胞中表达上调，并证实circRSF1是通过充当miR-146a-5p的海绵，抑制miR-146a-5p的表达而增加了Ras相关的C3肉毒杆菌毒素底物1（RAC1）的表达，从而提高细胞活力，促进LX-2细胞的炎症和纤维化表型。Zhou[[]ZhouYP,LvXY,QuH,etal.PreliminaryscreeningandfunctionalanalysisofcircularRNAsassociatedwithhepaticstellatecellactivation[J].Gene,2018,doi:10.1016/j.gene.2018.08.052.]等人提出mmu-circ-34116可能通过miR-22-3p/BMP7轴参与HSC的激活调控肝纤维化。Zhu[[]ZhuLL,RenTT,ZhuZX,etal.Thymosin-β4MediatesHepaticStellateCellActivationbyInterferingwithCircRNA-0067835/miR-155/FoxO3SignalingPathway[J].CellularPhysiologyandBiochemistry,2018,51(3):1389-1398.]等发现circRNA-0067835作为miR-155的海绵促进FOXO3a的表达进而参与肝纤维化过程，并证实circRNA-0067835基因的敲除通过引起G1期阻滞和促进细胞凋亡而显著降低LX-2细胞的增殖。Chen[[]ChenYH,YuanBY,WuZF,etal.MicroarrayprofilingofcircularRNAsandthepotentialregulatoryroleofhas-circ-0071410intheactivatedhumanhepaticstellatecellinducedbyirradiation[J].Gene,2017,629:35-42]等人发现抑制[]ChenYH,YuanBY,ChenGW,etal.CircularRNARSF1promotesinflammatoryandfibroticphenotypesofirradiatedhepaticstellatecellbymodulatingmiR-146a-5p[J].Journalofcellularphysiology,2020,doi:10.1002/jcp.29483.[]ZhouYP,LvXY,QuH,etal.PreliminaryscreeningandfunctionalanalysisofcircularRNAsassociatedwithhepaticstellatecellactivation[J].Gene,2018,doi:10.1016/j.gene.2018.08.052.[]ZhuLL,RenTT,ZhuZX,etal.Thymosin-β4MediatesHepaticStellateCellActivationbyInterferingwithCircRNA-0067835/miR-155/FoxO3SignalingPathway[J].CellularPhysiologyandBiochemistry,2018,51(3):1389-1398.[]ChenYH,YuanBY,WuZF,etal.MicroarrayprofilingofcircularRNAsandthepotentialregulatoryroleofhas-circ-0071410intheactivatedhumanhepaticstellatecellinducedbyirradiation[J].Gene,2017,629:35-42[]ZhouYP,LvXY,QuH,etal.DifferentialexpressionofcircularRNAsinhepatictissueinamodelofliverfibrosisandfunctionalanalysisoftheirtargetgenes[J].HepatologyResearch,2019,49(3):324-334.4非编码RNA与肝细胞癌原发性肝癌大多为肝细胞癌（hepatocellularcarcinoma，HCC），我国的肝癌患者多由慢性乙型肝炎发展而来，经历肝纤维化、肝硬化的过程，最终发展成为肝癌。在肝癌的治疗方面，放射性治疗敏感性差，药物化疗不良反应严重，手术治疗的复发率高，且疗效均不是特别可观。但是近些年来人们对非编码RNA的认识逐渐显露，发现非编码RNA与肿瘤的发生密切相关，对于肿瘤细胞的增殖、侵袭和转移有非常重要的调控功能，这对肝癌的治疗提供了另一研究方向。非编码RNA在HCC的进程中一般作为抑癌基因或者致癌基因来调控HCC，抑癌基因的低表达和致癌基因的高表达促进了肝癌细胞的增殖、侵入和迁移等；且常通过调控Wnt、NOTCH2、PIK3-AKT、MAPK等多条信号通路影响HCC的进展。4.1LncRNA与肝细胞癌病毒性肝炎是HCC的重要发病因素之一，Hu[[]HuZG,HuangPB,YanYC,etal.HepatitisBvirusXproteinrelatedlncRNAWEE2-AS1promoteshepatocellularcarcinomaproliferationandinvasion[J].BiochemicalandBiophysicalResearchCommunications,2018,doi:10.1016/j.bbrc.2018.11.091.]等首次发现LncRNAWEE2-AS1在HCC中高表达，促进了肝癌细胞的增殖、迁移、侵袭和细胞周期的进展，同时抑制了肝癌细胞的凋亡，且与HBV感染、肝血管侵犯、肿瘤分化不良及患者预后不良呈正相关，提出HBV/HBx-WEE2-AS1-FERMT3轴可作为HBV相关肝癌的治疗靶点。Zuo[[]ZuoK,KongL,XueD,etal.TheexpressionandroleoflncRNAAX800134inhepatitisBvirus-relatedhepatocellularcarcinoma[J].Virusgenes,2018,doi:10.1007/s11262-018-1564-1.]等发现在HBV阳性HCC中LncRNAAX800134的表达高于HBV阴性HCC，siRNA干扰沉默AX800134显著抑制HBx表达的HepG2细胞的生长和侵袭，并表明高表达的AX800134在肝癌中起致癌作用，其上调与病毒产物HBx和慢性炎症有关。说明LncRNAAX800134可作为HBV相关性肝细胞癌的生物治疗分子。另有研究表明LncRNA-BC017743和LncRNA-BC043430在乙型/丙型/丁型肝炎相关性肝癌组织中上调；LINC01152在此三种肝炎相关性肝癌组织中均下调；TMEVPG1在丙型/丁型肝炎相关性肝癌组织中下调；而一些LncRNA主要在特定的肝炎病毒相关的HCC中显著失调，比如HBV相关的HCC中的PCAT-29下调、HCV相关的HCC中的aHIF、PAR5下调以及HDV相关的HCC中的Y3下调[[]ZhangQ,MatsuuraK,KleinerDE,etal.AnalysisoflongnoncodingRNAexpressioninhepatocellularcarcinomaofdifferentviraletiology[J].Journaloftranslationalmedicine,2016,14(1):328-338.]。提示circRNA在病毒性肝炎相关性肝细胞癌的发展中起重要调控作用，可作为潜在治疗靶点。也有些circRNA在HCC中的异常表达不受病毒性肝炎的影响，如Zhong[]HuZG,HuangPB,YanYC,etal.HepatitisBvirusXproteinrelatedlncRNAWEE2-AS1promoteshepatocellularcarcinomaproliferationandinvasion[J].BiochemicalandBiophysicalResearchCommunications,2018,doi:10.1016/j.bbrc.2018.11.091.[]ZuoK,KongL,XueD,etal.TheexpressionandroleoflncRNAAX800134inhepatitisBvirus-relatedhepatocellularcarcinoma[J].Virusgenes,2018,doi:10.1007/s11262-018-1564-1.[]ZhangQ,MatsuuraK,KleinerDE,etal.AnalysisoflongnoncodingRNAexpressioninhepatocellularcarcinomaofdifferentviraletiology[J].Journaloftranslationalmedicine,2016,14(1):328-338.[]ZhongYC,LiY,SongT,etal.MiR-718mediatestheindirectinteractionbetweenlncRNASEMA3B-AS1andPTENtoregulatetheproliferationofhepatocellularcarcinomacells[J].Physiologicalgenomics,2019,51(10):500-505.LncRNA在HCC中的生物作用调控轴日渐清晰，如Hong[[]FanHX,LvP,MuT,etal.LncRNAn335586/miR-924/CKMT1Aaxiscontributestocellmigrationandinvasioninhepatocellularcarcinomacells[J].CancerLetters,2018,429:89-99.]等人证明在HBV阳性的HCC组织和细胞中，LncRNAn335586的表达显著增加，并证明n335586通过竞争性结合miR-924促进宿主基因CKMT1A的表达，继而促进肝癌细胞的迁移和侵袭、EMT及体内转移。即LncRNAn335586/miR-924/CKMT1A轴。此外，Unigene56159/miR-140-5p/Slug轴能有效地抑制靶基因片段的表达，从而显著促进了肝癌细胞的迁移、侵袭和上皮-间质转化[[]LvJ,FanHX,ZhaoXP,etal.Longnon-codingRNAUnigene56159promotesepithelial–mesenchymaltransitionbyactingasaceRNAofmiR-140-5pinhepatocellularcarcinomacells[J].CancerLetters,2016,382(2):166-175.]。还有研究表明一种LncRNA不仅通过一条调控轴控制HCC的进展，如表1所示：MALAT1作为miR-125a-3p的海绵继而调节FOXM1或作为miR-3064-5p的海绵通过FOXA1/CD24/Src途径参与肝癌的进展；GAS5通过miR-1323/TP53INP1轴或miR-182/ANGPTL1轴抑制肝癌细胞的侵袭和转移；[]FanHX,LvP,MuT,etal.LncRNAn335586/miR-924/CKMT1Aaxiscontributestocellmigrationandinvasioninhepatocellularcarcinomacells[J].CancerLetters,2018,429:89-99.[]LvJ,FanHX,ZhaoXP,etal.Longnon-codingRNAUnigene56159promotesepithelial–mesenchymaltransitionbyactingasaceRNAofmiR-140-5pinhepatocellularcarcinomacells[J].CancerLetters,2016,382(2):166-175.4.2circRNA与肝细胞癌随着对非编码RNA研究的逐渐丰富，circRNA对疾病的调控轴越来越受到关注，如circ-PRMT5/miR-188-5P/HK2轴在肝癌细胞的增殖、迁移和糖酵解中发挥重要作[[]DingZH,GuoL,DengZM,etal.Circ-PRMT5enhancestheproliferation,migrationandglycolysisofhepatomacellsbytargetingmiR-188-5p/HK2axis[J].AnnalsofHepatology,2020,doi:10.1016/j.aohep.2020.01.002.]，circ-14723/miR-16-5p/CCND1和circ-14723/miR-16-5p/CCNE1轴在大鼠LR细胞G1/S期阻滞中起到促进细胞增殖的关键作用[[]GuoXQ,XiLL,LiLF,etal.circRNA-14723promoteshepatocytesproliferationinratliverregenerationbyspongingrno-miR-16-5p[J].Journalofcellularphysiology,2020,doi:10.1002/jcp.29473.]，circ-0001498/miR-122/MAPK3K2轴参与HCV核心蛋白致癌的过程[[]PengJF.TheimpactofHCVcoreproteinontheexpressionoflncRNAandcircRNAinhumanHuh7hepatomacelllineandthepreliminarymechanismstudy[C].中国免疫学会.第十一届全国免疫学学术大会摘要汇编.中国免疫学会:中国免疫学会,2016:122-123.]，circPVT1/miR-3666/SIRT7轴[[]DingZH,GuoL,DengZM,etal.Circ-PRMT5enhancestheproliferation,migrationandglycolysisofhepatomacellsbytargetingmiR-188-5p/HK2axis[J].AnnalsofHepatology,2020,doi:10.1016/j.aohep.2020.01.002.[]GuoXQ,XiLL,LiLF,etal.circRNA-14723promoteshepatocytesproliferationinratliverregenerationbyspongingrno-miR-16-5p[J].Journalofcellularphysiology,2020,doi:10.1002/jcp.29473.[]PengJF.TheimpactofHCVcoreproteinontheexpressionoflncRNAandcircRNAinhumanHuh7hepatomacelllineandthepreliminarymechanismstudy[C].中国免疫学会.第十一届全国免疫学学术大会摘要汇编.中国免疫学会:中国免疫学会,2016:122-123.[]LiY,ShiHT,YuanJ,etal.DownregulationofcircularRNAcircPVT1restrictscellgrowthofhepatocellularcarcinomathroughdownregulationofSirtuin7viamicroRNA-3666[J].Clinicalandexperimentalpharmacology&physiology,2020,doi:10.1111/1440-1681.13273.[]SunXJ,GeXF,XuZY,etal.IdentificationofcircularRNA-microRNA-messengerRNAregulatorynetworkinhepatocellularcarcinomabyintegratedanalysis[J].Journalofgastroenterologyandhepatology,2020,35(1):157-164.此外，单纯某个基因的异常表达无法非常全面和准确的作为疾病的诊断分子，故提出联合检测两种或两种以上circRNA协助临床诊断，如吴光辉[[]吴光辉,李伟.环状RNAPTENP1、HIPK3联合高尔基体蛋白73对AFP阴性肝癌的诊断价值[J].肝脏,2019,24(05):531-534.]等人发现在AFP阴性肝癌（AFP-NHCC）患者血清中circRNAPTENP1水平降低，而circRNAHIPK3和GP73水平显著高于肝良性病变患者和健康人群（P<0.05），并最终提出联合检测circRNAPTENP1、circRNAHIPK3、GP73对[]吴光辉,李伟.环状RNAPTENP1、HIPK3联合高尔基体蛋白73对AFP阴性肝癌的诊断价值[J].肝脏,2019,24(05):531-534.5总结与展望在肝脏的损伤进程中，病毒性肝炎→肝纤维化→肝硬化→肝癌，是一个十分重要的疾病链，查阅文献发现，有些LncRNA在肝脏损伤的发生与进展中贯穿始终，在病毒性肝炎、肝纤维化、肝细胞癌中均异常表达，其作用机制也不完全相同，可通过不同的调控轴影响不同的肝脏损伤（表1）。这就为延缓肝脏的损伤、预防肝癌的发生提供了可能。表SEQ表格\*ARABIC1LncRNA与肝脏疾病的关系基因名称表达情况相关疾病机制参考文献HULC上调HCV受维甲酸X受体α（RXRA）介导[[][]SharmaG,TripathiSK,DasS.lncRNAHULCfacilitatesefficientloadingofHCV-coreproteinontolipiddropletsandsubsequentvirus-particlerelease[J].Cellularmicrobiology,2019,21(10):e13086-13095.上调肝纤维化通过抑制MAPK信号通路改善肝纤维化和减少HCs凋亡[[][]ShenXT,GuoHY,XuJJ,etal.InhibitionoflncRNAHULCimproveshepaticfibrosisandhepatocyteapoptosisbyinhibitingtheMAPKsignalingpathwayinratswithnonalcoholicfattyliverdisease[J].JournalofCellularPhysiology,2019,234(10):18169-18179.上调HCC通过miR-107/E2F1/SPHK1信号通路促进肿瘤血管生成[[][]LuZP,XiaoZL,LiuFB,etal.Longnon-codingRNAHULCpromotestumorangiogenesisinlivercancerbyup-regulatingsphingosinekinase1(SPHK1)[J].Oncotarget,2016,7(1):241-254.HOTAIR上调HCV通过HOTAIR-Sirt1信号途径引起肝细胞糖、脂代谢紊乱并参与HCV[[][]LiZQ,GuXY,HuJX,etal.HepatitisCviruscoreproteinimpairsmetabolicdisorderoflivercellviaHOTAIR-Sirt1signalling[J].Biosciencereports,2016,36(3):e00336-e00336.上调肝纤维化作为miR-124-3p的海绵或作为miR-148b的海绵并调节DNMT1/MEG3/p53通路[[][]ZhiSC,ChenSZ,LiYY,etal.RosiglitazoneInhibitsActivationofHepaticStellateCellsviaUp-RegulatingMicro-RNA-124-3ptoAlleviateHepaticFibrosis[J].Digestivediseasesandsciences,2019,64(6):1560-1570.[[][]Er-BaoB,WangYY,YangY,etal.Hotairfacilitateshepaticstellatecellsactivationandfibrogenesisintheliver[J].BBA-MolecularBasisofDisease,2017,1863(3):674-686.上调HCC通过激活Wnt/β-catenin信号通路促进HCC发展[[][]GaoJZ,LiJ,DUJL,etal.Longnon-codingRNAHOTAIRisamarkerforhepatocellularcarcinomaprogressionandtumorrecurrence[J].Oncologyletters,2016,11(3):1791-1798.MALAT1上调肝纤维化作为miR-101b的海绵，通过调节Racl的表达而影响肝星状细胞的增殖和活化[[][]PengXX,WanY,LiuWJ,etal.Protectiverolesofintra-arterialmildhypothermiaandarterialthrombolysisinacutecerebralinfarction[J].SpringerPlus,2016,5(1):1988-1993.上调HCC作为miR-3064-5p的海绵通过FOXA1/CD24/Src途径或作为miR-125a-3p的海绵通过调节FOXM1参与肝癌的进展[[][]LiuSH,QiuJ,HeGF,etal.LncRNAMALAT1actsasamiR-125a-3pspongetoregulateFOXM1expressionandpromotehepatocellularcarcinomaprogression[J].JournalofCancer,2019,10(26):6649-6659.[[][]ZhangP,HaM,LiLB,etal.MicroRNA-3064-5pspongedbyMALAT1suppressesangiogenesisinhumanhepatocellularcarcinomabytargetingtheFOXA1/CD24/Srcpathway[J].FASEBjournal:officialpublicationoftheFederationofAmericanSocietiesforExperimentalBiology,2020,34(1):66-81.GAS5下调肝纤维化作为miR-23a的海绵，通过lncRNAGAS5/miR-23a/PTEN/PI3K/Akt/mTOR/Snail信号通路在肝纤维化中起调控作用[[][]DongZH,LiS,WangXH,etal.lncRNAGAS5restrainsCCl4-inducedhepaticfibrosisbytargetingmiR-23athroughthePTEN/PI3K/Aktsignalingpathway[J].Americanjournalofphysiology.Gastrointestinalandliverphysiology,2019,316(4):G539-G550.下调HCC通过miR-1323/TP53INP1轴或miR-182/ANGPTL1轴抑制肝癌细胞的侵袭和转移[[][]ZhangFJ,YangC,XingZY,etal.LncRNAGAS5-mediatedmiR-1323promotestumorprogressionbytargetingTP53INP1inhepatocellularcarcinoma[J].OncoTargetsandtherapy,2019,12:4013-4023.[[][]ChenF,LiYH,LiMJ,etal.LongnoncodingRNAGAS5inhibitsmetastasisbytargetingmiR-182/ANGPTL1inhepatocellularcarcinoma[J].Americanjournalofcancerresearch,2019,9(1):108-121.MEG3下调肝纤维化过表达的MEG3激活P53并介导细胞色素C的释放，引起caspase3依赖的肝星状细胞凋亡[[][]HeY,WuYT,HuangC,etal.InhibitoryeffectsoflongnoncodingRNAMEG3onhepaticstellatecellsactivationandliverfibrogenesis[J].BBA-MolecularBasisofDisease,2014,1842(11):2204-2215.下调HCC以p53、内质网应激两种方式，介导肝癌细胞凋亡[[][]ChenRP,HuangZL,LiuLX,etal.Involvementofendoplasmicreticulumstressandp53inlncRNAMEG3-inducedhumanhepatomaHepG2cellapoptosis[J].Oncologyreports,2016,36(3):1649-1657.ATB上调肝纤维化通过激活HSC和竞争性结合miR-425-5p，增加I型胶原的产生，促进HCV诱导的肝纤维化[[][]FuN,NiuXM,WangY,etal.RoleofLncRNA-activatedbytransforminggrowthfactorbetaintheprogressionofhepatitisCvirus-relatedliverfibrosis[J].Discoverymedicine,2016,22(119):29-42.上调HCC通过激活叶酸结合蛋白（YAP）和增加自噬相关蛋白5（ATG5）的表达来调节自噬，进而参与HCC[[][]WangCZ,YanGX,DongDS,etal.LncRNA-ATBpromotesautophagybyactivatingYes-associatedproteinandinducingautophagy-relatedprotein5expressioninhepatocellularcarcinoma[J].WorldJournalofGastroenterology,2019,25(35):5310-5322.PVT1上调肝纤维化通过PVT1/miR-152/PTCH1轴参与肝纤维化的EMT过程[[][]ZhengJJ,YuFJ,DongPH,etal.Longnon-codingRNAPVT1activateshepaticstellatecellsthroughcompetitivelybindingmicroRNA-152[J].Oncotarget,2016,7(39):62886-62897.上调HCC通过miR-365/AGT3途径参与肝癌细胞的自噬或通过miR-150/HIG2轴参与HCC[[][]YangL,PengXQ,JinHY,etal.Longnon-codingRNAPVT1promotesautophagyasceRNAtotargetATG3byspongingmicroRNA-365inhepatocellularcarcinoma[J].Gene,2019,697:94-102.[[][]XuYXX,LuoXX,HeWG,etal.LongNon-CodingRNAPVT1/miR-150/HIG2AxisRegulatestheProliferation,InvasionandtheBalanceofIronMetabolismofHepatocellularCarcinoma[J].CellularPhysiologyandBiochemistry,2018,49(4):1403-1419.而circRNA与肝脏相关疾病的研究目前尚处于起步阶段，且研究的重点放在了HCC上，对于病毒性肝炎和肝纤维化的研究相对较少。关于circRNA在HCC中的表达，其表达量常与临床病理参数相关，如肿瘤的大小、数目，肝硬化的程度，MVI（microvascularinvasion,微血管浸润），血清AFP（alphafetoprotein,甲胎蛋白），TNM分期，BCLC分期等（表2），并存在统计学意义，故circRNA根据相关性因素可作为诊断分子或预后分子。如circCDYL、circDYNC1H1、circHIPK3、circ-03809、circ-0001445、circ-0005986的表达量与HCC肿瘤的大小数目、分化的程度、有无转移或分期相关，可作为辅助分级分期诊断的生物分子；circMTO1、circ-100338、circ-000673的表达量均与生存期相关，可作为预后分子；circ-000673、circC3P1既与肿瘤的大小数目、分期相关，又与患者的生存期相关，可做诊断分子又可做预后分子。表SEQ表格\*ARABIC2circRNA与HCC的关系基因名称表达情况相关疾病机制临床相关性参考文献circCDYL上调HCC调控NCL-PIK3-AKT和NOTCH2信号通路的活化与BCLC分期相关[[][]WeiYP,ChenX,LiangC,etal.ANoncodingRegulatoryRNAsNetworkDrivenbyCirc-CDYLActsSpecificallyintheEarlyStagesHepatocellularCarcinoma[J].Hepatology(Baltimore,Md.),2020,71(1):130-147.circDYNC1H1上调HCC作为miR-140-5p的海绵，从而增强SULT2B1的表达与肿瘤体积相关[[][]WangZY,ZhuZ,WangHF,etal.DownregulationofcircDYNC1H1exhibitsinhibitoreffectoncellproliferationandmigrationinhepatocellularcarcinomathroughmiR-140-5p[J].Journalofcellularphysiology,2019,234(10):17775-17785.circ-0005705上调HCC海绵吸附miR-335，进一步调节MAPK1的表达与肿瘤大小有关[[][]YangXY,SongH,ZiZG,etal.Circ_0005075promoteshepatocellularcarcinomaprogressionbysuppressionofmicroRNA-335[J].Journalofcellularphysiology,2019,234(12):21937-21946.[[][]ShangXC,LiGZ,LiuH,etal.ComprehensiveCircularRNAProfilingRevealsThathsa_circ_0005075,aNewCircularRNABiomarker,IsInvolvedinHepatocellularCr