简介:MicroRNA简称为miRNA,通常长度为19~25个核苷酸,是一类重要高度保守的非编码的小分子单链RNA。最新有关研究表明:miRNA与肿瘤存在着紧密关联,已在miRNA和肿瘤的发生、诊断及治疗等研究领域取得了一系列进展。本文从miRNA的概念与特征、miRNA的产生、作用机制及与肿瘤的关系等方面作一阐述。1miRNA的发现及其生物学特性1993年,Lee等[1]在秀丽新小杆线虫(C.elegans)中发现了第一个定时调控胚胎后期发育的基因lin-4,随后在多种生物物种中鉴别出上千种miRNAs[2-3]。许多miRNA的表达水平具有较强的保守性、基因簇集现象、时空特异性及组织特异性:①保守性。在已克隆到的miRNA中,几乎所有的miRNAs的基因存在于相近动物中,例如,C.elegans中多于1/3的miRNAs与人类同源[4]。②基因簇集现象。目前已知miRNA基因簇现象在果蝇中广泛存在,有超过一半的miRNAs是簇集的[5]。③时空特异性。目前研究较清楚的lin-4与let-7呈时间特异性表达。在C.elegans中,lin-4只在幼虫的第一期和第二期存...
简介:MicroRNAs(miRNAs)areendogenouslyexpressednon-codingRNAsof20-24nucleotides,whichpost-transcriptionallyregulategeneexpressioninplantsandanimals.RecentlyithasbeenrecognizedthatmiRNAscompriseoneoftheabundantgenefamiliesinmulticellularspecies,andtheirregulatoryfunctionsinvariousbiologicalprocessesarewidelyspread.Therehasbeenasurgeintheresearchactivitiesinthisfieldinthepastfewyears.Fromtheverybeginning,computationalmethodshavebeenutilizedasindispensabletools,andmanydiscoverieshavebeenobtainedthroughcombinationofexperimentalandcomputationalapproaches.Inthisreview,bothbiologicalandcomputationalaspectsofmiRNAwillbediscussed.AbriefhistoryofthediscoveryofmiRNAanddiscussionofmicroarrayapplicationsinmiRNAresearcharealsoincluded.
简介:目的:分析microRNA(miRNA)相关专利,为我国miRNA科学研究和决策提供一定的参考。方法:运用专利文献计量学方法,使用TDA软件和Excel程序,对DII数据库中收录的miRNA相关专利的年份、国别、专利家族分布、专利权人、发明人和Derwent手工码进行分析。结果:发现了miRNA相关专利的年份分布、主要国家或组织的专利家族分布、前十位专利权人分布、前十位发明人分布及所涉及的Derwent手工代码分布情况。结论:我国在相关专利数量上虽然处于相对领先地位,但与美国等国相比仍存在很大差距,同时miRNA相关专利的专利家族多局限于本国,未曾形成一种广泛的多国高度分布的专利家族形势,缺乏对专利主动运用以获取专利信息和竞争优势的意识。
简介:MicroRNAs(miRNAs)是他们在植物和动物的目标基因的重要post-transcriptional管理者。miRNAs通常长是20-24核苷酸。尽管有他们的不平常地小的尺寸,miRNA基因家庭的进化历史似乎类似于编码theirprotein对应物。与在动物染色体的小却丰富的miRNA家庭相对照,植物有少数但是更大的miRNA基因家庭。植物miRNA基因家庭的成员经常是高度类似的,建议经由双人脚踏车基因复制和部分复制事件的最近的扩大。尽管许多miRNA基因越过植物种类被保存,一样的基因家庭在不同种类在尺寸和genomic组织显著地变化,它可以在目标基因规定引起剂量效果和空间、时间的差别。在这评论,我们在理解植物miRNA基因家庭的进化总结当前的进步。
简介:摘要MicroRNAs已经成为一种重要的调节脂质代谢的因子。最近发现的microRNA-33aandb(miR-33a/b)在体内胆固醇和脂肪酸代谢动态平衡中起着很重要的调节作用。这些microRNA嵌入在固醇响应元件结合蛋白基因(SREBF2和SREBF1)中,通过抑制参与到胆固醇输出和脂肪酸氧化的基因,比如ABCA1,CROT,CPT1,HADHB和PRKAA1,转录后调节胆固醇和脂肪酸代谢。miR-33a/b促进细胞内脂质沉积。在新近的动物实验研究中表明抑制这些小干扰RNA对脂蛋白代谢的调节有很显著的影响,包括增加血浆中高密度脂蛋白(HDL)和减少极低密度脂蛋白(VLDL)中甘油三酯的代谢。这些新的发现支持了microRNA拮抗剂在治疗血脂异常、动脉粥样硬化和相关代谢疾病中的潜在作用。
简介:AbstractPreoperative neoadjuvant chemoradiotherapy, combined with total mesorectal excision, has become the standard treatment for advanced localized rectal cancer (RC). However, the biological complexity and heterogeneity of tumors may contribute to cancer recurrence and metastasis in patients with radiotherapy-resistant RC. The identification of factors leading to radioresistance and markers of radiosensitivity is critical to identify responsive patients and improve radiotherapy outcomes. MicroRNAs (miRNAs) are small, endogenous, and noncoding RNAs that affect various cellular and molecular targets. miRNAs have been shown to play important roles in multiple biological processes associated with RC. In this review, we summarized the signaling pathways of miRNAs, including apoptosis, autophagy, the cell cycle, DNA damage repair, proliferation, and metastasis during radiotherapy in patients with RC. Also, we evaluated the potential role of miRNAs as radiotherapeutic biomarkers for RC.
简介:Objective:Puremucinousbreastcarcinoma(PMBC)isanuncommonhistologicaltypeofbreastcancercharacterizedbyalargeamountofmucinproduction.MicroRNA(miRNA)isalargeclassofsmallnoncodingRNAofabout22ntinvolvedintheregulationofvariousbiologicalprocesses.ThisstudyaimstoidentifythemiRNAexpressionprofileinPMBC.Methods:MiRNAexpressionprofilesin11PMBCswereanalyzedbymiRNA-microarrayandreal-timepolymerasechainreaction(PCR).Thirty-onePMBCsand27invasiveductalcarcinomaofnospecialtypes(IDC-NSTs)wereassessedbyimmunohistochemistryusingantibodiesagainstER,PR-progesteronereceptor,HER2,Ki-67,Bcl-2,p53,PCNA,andCK5and6.Results:WeanalyzedthemiRNAexpressionin11PMBCsandcorrespondingnormaltissuesusingmiRNA-microarrayandreal-timePCR,andfoundthatmiR-143andmiR-224-5pweresignificantlydownregulatedinmucinouscarcinomatissue.ComparedwithIDC-NSTs,PMBCshowedasignificantlyhigherERpositiverate,lowerHER-2positiverate,andlowercellproliferationrates.Conclusions:Toourknowledge,thisisthefirststudytodemonstratethemiRNAexpressionprofileofPMBC,andourfindingsmayleadtofurtherunderstandingofthistypeofbreastcancer.
简介:microRNA(miRNA)是一类长度为19-25个核苷酸的非常保守的非编码小RNA分子,在真核生物体内通过与mRNA的3'非翻译区序列不完全互补结合促使mRNA降解或抑制翻译,从而在转录后水平调控基因表达。miRNA在生物体内参与了细胞增殖与凋亡、生长发育、代谢活化、DNA修复等一系列生物学过程,与多种疾病尤其是肿瘤的发生发展密切相关。对miRNA的功能研究已发展到其分子机制层面,大量集中于其靶基因的预测和鉴定及调控相关表观遗传因子,为疾病的诊断、治疗及预后提供了新的线索。我们就miRNA的合成、功能研究及miRNA在临床上的应用前景做简要综述。
简介:摘要目的分析不同分期及分级膀胱癌肿瘤组织中microRNA-21(miR-21)及microRNA-205(miR-205)表达量差异。方法将2014年1月至2014年12月间就诊的138例膀胱癌患者作为观察对象,根据病理分期,将患者分为T1期的A组(46例)、T2期的B组(34例)、T3期的C组(34例)及T4期的D组(24例),对比四组间miR-21及miR-205表达量差异;并根据病理分级,将患者分为低级组(88例)及高级组(50例),对比两组间miR-21及miR-205表达量差异。结果病理分期四组间,A组miR-21相对表达量最低,miR-205相对表达量最高,而D组miR-21相对表达量最高,miR-205相对表达量最低(P<0.05)。而病理分级两组间,低级组miR-21相对表达量明显最低高级组,miR-205相对表达量明显低于高级组(P<0.05)。结论不同分期及分级膀胱癌肿瘤组织中miR-21及miR-205表达量存在显著的差异。
简介:ObjectiveTocharacterizemicroRNA(miRNA)expressionprofileinmicrodissectedauditoryepitheliafromtheCorti'sOrganinnewbornandadultrats.MethodsTheTaqManMicroRNAArrayswereusedtoidentifyexpressionofmicroRNAinthenewbornandadultgroups.GOanalysiswasappliedtoanalyzethemainfunctionofthedifferentialexpressiongenesaccordingtotheGeneOntologywhichisthekeyfunctionalclassificationofNCBI.Similarly,PathwayanalysiswasusedtofindoutthesignificantpathwayofthedifferentialgenesaccordingtoKEGG,BiocartaandReatome.ResultsIncreasedexpressionwasseenin16miRNAsinmatureratcomparedtonewbornrats,withincreasedfoldingrangingfrom17to600folds.Expressionlevelsin2miRNAswerereducedinmaturerats,namelyrno-miR-29candrno-miR-29a.Thehigh-enrichmentGOstargetedbyover-expressedmiRNAswerenegativeregulationofepithelialcelldifferentiation,common-partnerSMADproteinphosphorylation,mesenchymal-epithelialcellsignaling,regulationoftransforminggrowthfactorbeta2production,etc.FunctionalanalysisofmiRNAsbyKEGGrevealedthat19signaltransductionpathwayswereupregulatedand14weredownregulated.ConclusionsThedifferenceinmiRNAexpressionpatternsintheorganofCortibetweenneonatalandadultratsmaybecloselyrelatedtomaturationoftheorganofCortiandlossofproliferativecapacityofinnerearhaircells,andTGFβsignalingmayplayanimportantroleinhaircellsregeneration.
简介:目的通过对结直肠癌患者血清进行实时定量PCR检测,筛选出结直肠癌转移相关的miRNA。方法通过文献检索,筛选出11个结直肠癌转移相关的miRNA(miRs-31,335,206,141,126,200b,200c,21,Let7a,Let7b和Let7c),收集2007年7月至2013年4月北京友谊医院收治的术前留置血清的结直肠癌转移(IV期)病例共计108例,其中结直肠肝转移患者72例,其他脏器转移患者36例;并纳入2008年1月至2010年6月术前留置血清的局灶性结直肠癌(L-CRC)(I-III期)病例共计116例作为对照组进行研究。通过对两组患者血清样本进行实时定量PCR检测结果找出结直肠癌转移相关miRNA。结果筛选出11个转移相关的miRNA中的7个miRNA(miRs-31、141、126、21、Let7a、Let7b和Let7c)可以从血清中被检测到。与局灶性结直肠癌患者相比,miR-141,miR-126,Let-7a和miR-21在转移性结直肠癌患者的血清中表达具有显著性差异(P〈0.0001,P〈0.0001,P=0.0120和P〈0.0001),可以作为结直肠癌转移相关miRNA。结论7个转移相关MiRNAs:miRs-31、141、126、21、Let7a、Let7b和Let7c可以从结直肠癌患者血清中被检测到;miR-141,miR-126,Let-7a和miR-21可以作为结直肠癌转移相关miRNA。
简介:MicroRNAs(miRNAs)aredynamicallyregulatedduringneurodevelopment,yetfewreportshaveexaminedtheirroleinspinabifida.Inthisstudy,weusedanestablishedfetalratmodelofspinabifidainducedbyintragastricallyadministeringoliveoil-containingall-transretinoicacidtodamsonday10ofpregnancy.Damsthatreceivedintragastricadministrationofall-transretinoicacid-freeoliveoilservedascontrols.ThemiRNAexpressionprofileintheamnioticfluidofratsat20daysofpregnancywasanalyzedusinganmiRNAmicroarrayassay.Comparedwiththatincontrolfetuses,theexpressionofmiRNA-9,miRNA-124a,andmiRNA-138wassignificantlydecreased(>2-fold),whereastheexpressionofmiRNA-134wassignificantlyincreased(>4-fold)intheamnioticfluidofratswithfetusesmodelingspinabifida.Theseresultswerevalidatedusingreal-timequantitativereverse-transcriptionpolymerasechainreaction.HierarchicalclusteringanalysisofthemicroarraydatashowedthatthesedifferentiallyexpressedmiRNAscoulddistinguishfetusesmodelingspinabifidafromcontrolfetuses.OurbioinformaticsanalysissuggestedthatthesedifferentiallyexpressedmiRNAswereassociatedwithmanycytologicalpathways,includinganervoussystemdevelopmentsignalingpathway.ThesefindingsindicatethatfurtherstudiesarewarrantedexaminingtheroleofmiRNAsthroughtheirregulationofavarietyofcellfunctionalpathwaysinthepathogenesisofspinabifida.Suchstudiesmayprovidenoveltargetsfortheearlydiagnosisandtreatmentofspinabifida.