靶向人端粒酶逆转录酶进行RNAi的逆转录病毒载体的构建

发布时间:2015-04-11 17:43:29

靶向人端粒酶逆转录酶进行RNAi的逆转录病毒载体的构建王全师1,王欣璐2,李华3,王巧愚1,王全颖4,杨广笑4(1南方医科大学南方医院PET中心,广东广州510515;2广州军区广州总医院核医学科PET中心,广东广州510010;3中山大学附属第三医院,广东广州510630;4西安华广生物工程公司,陕西西安710025)摘要:目的构建靶向性干扰人端粒酶逆转录酶表达的特异性小干扰RNA的真核表达载体。方法采用PCR法分别扩增增强型绿色荧光蛋白的DNA序列、U6启动子序列和靶向性干扰人端粒酶逆转录酶的特异性小干扰RNA对应的DNA序列,随后将与之相应的DNA序列片断依次克隆入真核表达载体pLXSN中,并通过限制性内切酶和测序对该重组表达载体进行鉴定。以荧光显微镜和利用流式细胞仪分析重组病毒表达EGFP蛋白的情况。以MTT方法检测初步分析重组病毒对人Hela细胞的RNAi效果。结果限制性内切酶酶切和测序结果均表明成功构建了靶向人端粒酶逆转录酶的小干扰RNA的逆转录病毒表达载体pLXSN/EGFP-U6-siTERT。以磷酸钙共转染法制备的重组逆转录病毒滴定了病毒滴度后,重组病毒感染人Hela细胞24h时用流式细胞仪测得EGFP表达的阳性率为24.1%。重组逆转录病毒感染人Hela细胞48h时,MTT实验测得细胞死亡率为53.2%。结论成功构建了针对人端粒酶逆转录酶小干扰RNA的逆转录病毒表达载体pLXSN/EGFP-U6-siTERT,并制备了重组逆转录病毒,初步观察了效应,为进一步利用小干扰RNA技术研究肿瘤的基因治疗奠定了基础。关键词:RNA干扰;逆转录病毒载体;人端粒酶逆转录酶中图分类号:R373.5文献标识码:A文章编号:1673-4254(2006)12-1715-05ConstructionofaretroviralvectorforRNAinterferencetargetinghumantelomerasereversetranscriptaseWANGQuan-shi1,WANGXin-lu2,LIHua3,WANGQiao-yu1,WANGQuan-ying4,YANGGuang-xiao41PETCenter,NanfangHospital,SouthernMedicalUniversity,Guangzhou510515,China;2PETCenterofDepartmentofNuclearMedicine,GuangzhouGeneralHospitalofGuangzhouCommand,Guangzhou510010,China;3ThirdAffiliatedHospitalofSunYat-senUniversity,Guangzhou510630,China;4Xi'anHuaguangBioengineeringCompany,Xi'an710025,ChinaAbstract:ObjectiveToconstructarecombinantretroviralvectorforRNAinterferencetargetinghumantelomerasereversetranscriptase(hTERT).MethodsThesequencescodingforenhancedfluorescenceprotein(EGFP),U6promoterandasmallinterferingRNA(siRNA)targetinghTERTwereamplifiedbyPCR,respectively,andsub-clonedsequentiallyintotheretroviralshuttleplasmidpLXSNtoconstructtheplasmidpLXSN-EGFP-U6-siTERT.Therecombinantexpressionplasmidwasidentifiedbyrestrictionenzymedigestionandsequencing.FluorescencemicroscopyandflowcytometrywereemployedtoanalyzeEGFPexpressioninNIH3T3transfectedwiththerecombinantplasmid,andMMTassaywasperformedtoevaluatethegrowthinhibitionofHelacellsresultingfromRNAinterferencemediatedbytheplasmid.ResultsSequenceanalysisandrestrictionenzymedigestionshowedthattherecombinantexpressionplasmidpLXSN-EGFP-U6-siTERTwasconstructedsuccessfully.Twenty-fourhoursaftertransfectionofNIH3T3cellswiththerecombinantplasmid,theexpressionrateofEGFPreached24.1%asshownbyflowcytometry.MTTassaydemonstratedacelldeathrateof53.2%72haftertransfectionofHelacellswiththeplasmid.ConclusionThesuccessfulconstructionoftherecombinantretroviralplasmidmediatingpotentcellgrowthinhibitionsuggeststhegreatpotentialofRNAinterferencetechniqueinsuppressinghTERTexpressioninmammaliantumorcells.Keywords:RNAinterference;retroviralvector;humantelomerasereversetranscriptaseRNA干扰(RNAinterference,RNAi)是生物界中一种古老而且高度保守的现象,是基因转录后沉默作用(post-transcriptionalgenesilencing,PTGs)的重要机制之一。它能依赖短RNA引导序列介导特异性核酸酶识别并降解靶基因内源性mRNA,在转录后水平干扰基因表达[1-4]。本研究设计构建了针对端粒酶逆转录酶(humantelomerasereversetranscriptase,telomerasecatalyticsubunit,hTERT)的特异性siRNA的真核表达载体。hTERT是端粒酶活性的主要决定因素,收稿日期:2005-10-20基金项目:国家自然科学基金(30370426,30500136),广东省科技计划项目(2003C32729);广东省自然科学基金(06021352)SupportedbyNationalNaturalScienceFoundationofChina(30370426,30500136),Sci-techResearchDevelopmentProgramofGuangdongProvince(2003C32729),NaturalScienceFoundtionofGuangdongProvince(06021352)作者简介:王全师(1959-),男,副主任医师,博士,电话:020-61642127,E-mail:wqslph@163.net通讯作者:王欣璐,电话:020-87795061,E-mail:71lu@163.com2006;26(12)南方医科大学学报(JSouthMedUniv)1715・・

靶向人端粒酶逆转录酶进行RNAi的逆转录病毒载体的构建

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