Cloning of CRABS CLAW Gene from Brassica napus and Construction of Its RNA Interference Expression Vector

CRABS ClAW （CRC） is a member of the YABBYA transcription factor gene family that plays an important role in floral organ development of plants. This study aimed to further investigate the regulatory function of CRC transcription factor in the development of floral organs of rape （Brassica napus L. ）. A 580 bp fragment of CRC gene was cloned by RT-PCR from total RNA of buds of rape cultivar Ningyou No. 10 to construct an inverted repeated expression cassette of CRC gene using intermediate vector pHturieane. Firstly, CRC gene fragment was positively inserted into the 5＇ end of a spliceable intron and negatively inserted into the 3＇ end of the intron. Subsequently, CaMV35S promoter sequence and inverted repeated expression cassette of CRC gene were transferred into pUC18 multiple clone site of binary expression vector pCAMBIAI1390. The constructed interference expression vector was named pA6-CRCi, which was further confirmed by restriction enzyme digestion and sequencing.

Inhibition of hepatitis B virus expression and replication by RNA interference in HepG2.2.15

AIM： To observe the inhibition of hepatitis B virus replication and expression by transfecting vector-based small interference RNA （siRNA） pGenesiI-HBV X targeting HBV X gene region into HepG2.2.15 cells. METHODS：pGenesil-HBV X was constructed and transfected into HepG2.2.15 cells via lipofection. HBV antigen secretion was determined 24, 48, and 72 h after transfection by time-resolved immunofluorometric assays （TRFIA）. HBV replication was examined by fluorescence quantitative PCR, and the expression of cytoplasmic viral proteins was determined by immunohistochemistry. RESULTS： The secretion of HBsAg and HBeAg into the supernatant was found to be inhibited by 28.5% and 32.2% （P 〈 0.01）, and by 38.67% （P 〈 0.05） and 42.86% （P 〈 0.01） at 48 h and 72 h after pGenesil-HBV X transfection, respectively. Immunohistochemical staining for cytoplasmic HBsAg showed a similar decline in HepG2.2.15 cells 48 h after transfection. The number of HBV genomes within culture supernatants was also significantly decreased 48 h and 72 h post-transfection as quantified by fluorescence PCR （P 〈 0.05）. CONCLUSION： In HepG2.2.15 cells, HBV replication and expression is inhibited by vector-based siRNA pGenesil- HBV X targeting the HBV X coding region.

Harnessing the RNA interference pathway to advance treatment and prevention of hepatocellular carcinoma

Primary liver cancer is the fifth most common malignan- cy in the world and is a leading cause of cancer-related mortality.Available treatment for hepatocellular carcino- ma(HCC),the commonest primary liver cancer,is rarely curative and there is a need to develop therapy that is more effective.Specific and powerful gene silencing that can be achieved by activating RNA interference(RNAi) has generated enthusiasm for exploiting this pathway for HCC therapy.Many studies have been carried out with the aim of silencing HCC-related cellular oncogenes or the hepatocarcinogenic hepatitis B virus(HBV)and hepatitis C virus(HCV).Proof of principle studies have demonstrated promising results,and an early clinical trial assessing RNAi-based HBV therapy is currently in progress.Although the data augur well,there are several significant hurdles that need to be overcome before the goal of RNAi-based therapy for HCC is realized.Particu- larly important are the efficient and safe delivery of RNAi effecters to target malignant tissue and the limitation of unintended harmful non-specific effects.

Down-regulation of IL-8 expression in human airway epithelial cells through helper-dependent adenoviral-mediated RNA interference

Interleukin (IL)-8 is a potent neutrophil chemotactic factor and a crucial mediator in neutrophil-dependent inflammation.Various cell types produce IL-8, either in response to external stimuli such as cytokines or bacterial infection, or aftermalignant transformation. Anti-IL-8 strategies have been considered for anti-inflammatory therapy. In this paper wedemonstrate that the RNA interference technique can be used to efficiently down-regulate IL-8 protein expression inairway epithelial cells. We used a helper-dependent adenoviral vector to express a small hairpin (sh)RNA targetinghuman IL-8 in cultured airway epithelial cells (IB3-1, Cftr-/-; C38, Cftr-corrected) stimulated with TNF-α, IL-1β orheat-inactivated Burkholderia cenocepacia. Stimulated IL-8 expression in IB3-1 and C38 cells was significantly reducedby shRNA expression. The shRNA targeting IL-8 had no effect on the activation of NF-κB, or on the protein levels ofIκB or IL-6, suggesting that this anti-IL-8 strategy was highly specific, and therefore may offer potential for thetreatment of inflammatory diseases.

Optimization of the construction of recombinant plasmids PPARγ-pSUPER-EGFP for RNA interference

Objective：To construct and identify the recombinant plasmids PPARγ-pSUPER-EGFP for RNA interference. Methods： The pSUPER-EGFP vectors were used to transcribe functional short interfering RNA （siRNA）. Four pairs of 64 nt PPARγ siRNA encoding sequences were inserted into the downstream of the H1 promoter. The recombinant plasmids were confirmed by double digestion with the enzymes and sequencing. Western blotting was used to examine the silencing effect of PPARγ gene in RAW264.7 cells. Following procedures were used to optimize the experiments： the oligonucleotides were incubated 5 min at 95 C and cooled automatically in boiled water bath to anneal, and then phosphorylated oligonucleotides, pSUPER-EGFP plasmids was digested with Bgl Ⅱ and Hind Ⅲ , and the product was ligated into digested pSUPER-EGFP plasmids, and transforming the ligation products followed by screening and identifying positive clones. Results ：Four kinds of positive clones producing 285 bp fragments were selected. Sequencing further proved their correctness. Four recombinant plasmids containing corresponding PPARγ gene-specific target sequences induced the silencing of its target gene more or less. Conclusion： The optimizing method in constructing these recombinant plasmids serves other plasmid-based RNA interference research. The final plasmids PPARγ-pSUPER-EGFP established the basis for research on the function of PPARγ gene.

Construction and identification of an RNA interference lentivirus vector targeting the Ras homology C gene of melanoma cells

Background Melanoma has the highest mortality among all superficial malignant tumors.The poor prognosis is due to its high metastasis rate and the lack of therapeutic targets.As a molecular switch that controls tumor metastasis,Ras homology C （RhoC） has been correlated with tumor progression,especially tumor invasion and metastasis.However,little research has been done about the effects of RNA interference （RNAi） targeting RhoC on the invasion and metastasis of melanoma.In this study,we constructed an RNAi lentivirus vector targeting the RhoC gene of melanoma cells and identified its silencing effects on the RhoC gene.Methods Based on the RhoC gene encoding information,three pGPU6/GFP/Neo-short hairpin （shRNA） plasmids were constructed.After detecting their silencing effects on the RhoC gene of A375 cells,the most effective pGPU6/GFP/ Neo-shRNA plasmid was packed with lentivirus to construct the recombinant pLenti6.3-EGFP-453 targeting RhoC.The lentivirus vector was used to infect A375 cells,and then the expression of RhoC mRNA and protein were determined with real-time PCR and Western blotting.Results The plasmids pGPU6/GFP/Neo-shRNA 336,pGPU6/GFP/Neo-shRNA 453,and pGPU6/GFP/Neo-shRNA 680 were constructed.After they were transfected into A375 cells,the expressions of RhoC mRNA and protein were 1.47±0.26,1.13±0.16,1.39±0.11 and 70.98±9.21,50.67±6.06,65.77±4.06,respectively.pGPU6/GFP/Neo-shRNA 453 was the most effective sequence,and was used to successfully construct the pLenti6.3-EGFP-453 lentiviral vector targeting RhoC.pLenti6.3-EGFP-453 was used to infect A375 cells.The expression of RhoC mRNA and protein were 1.05±0.05 and 62.04±15.86 in the lentivirus group,4.21±0.24 and 220.86±24.07 in the negative lentivirus control group,and 4.63±0.32 and 257.39±12.30 in the normal control group respectively with the difference between the lentivirus group and the control groups being statistically significant （P ＜0.05）.Conclusion The successfully constructed pLenti6.3-EGFP-453 vector targeting the RhoC can effectively infect human melanoma A375 cells in vitro,and significantly inhibit the RhoC mRNA and protein expression.

Construction and identification of lentiviral RNA interference vector of rat leptin receptor gene

Leptin resistance is a main mechanism of acquired childhood obesity,and the suppression of long form of leptin receptor(OBRb)gene expression in diet-induced obese rats indicates that the down-regulation of OBRb gene expression plays a pivotal role in the mechanism of leptin resistance.The aim of the present study was to construct the lentiviral RNA interference(RNAi)vector of rat OBRb gene and evaluate the effects of siRNA on silencing OBRb gene expression.The target sequence of siRNA-OBRb was designed,and the com-plementary DNA containing both sense and antisense oligonucleotides was synthesized.After phosphorylation and annealing,these double-stranded DNA was cloned to pRNA-lentivector-VGFP to construct pRNA-Lenti-OBRb-VGFP recombinants with U6-containing promoter,target sequence and Poly III terminator.Then,the products were confirmed by electrophoresis and sequencing analy-sis,and the effects of RNAi on reducing gene expression were further confirmed by real-time polymerase chain reaction in transfected rat glioma cells expressing OBRb.The target sequence of siRNA-OBRb was successfully cloned to pRNA-lentivector-VGFP,and the RNAi protocol specifically reduced the expression of OBRb mRNA by approximately 80%compared with controls in transfected rat glioma cells.The successful construction of rat lentivirus vectors expressing OBRb-specific shRNA may be useful for further investigation in vivo.

RNA结合蛋白Lin28A差异表达可调控牙周膜干细胞的成骨分化

背景:Lin28A能影响细胞活动的多个方面,包括胚胎干细胞的自我更新、体细胞的重编程、个体的生长发育、组织代谢及致癌作用等,而它对牙周膜干细胞成骨分化的影响国内外均没有深入研究,其影响机制更未见报道。目的:探索Lin28A对牙周膜干细胞成骨分化能力的影响。方法:经典酶消化法分离、培养人牙周膜干细胞,qRT-PCR检测Lin28A在该类细胞中的分布情况及其在成骨诱导不同时间的差异性表达;构建Lin28A过表达及干扰表达的慢病毒载体转染至牙周膜干细胞,荧光显微镜观察转染效果;qRT-PCR验证慢病毒转染后Lin28A的表达差异,并进一步从正反两个方面检测成骨诱导培养过程中成骨基因碱性磷酸酶、Runt相关转录因子2和骨桥蛋白的表达量以及碱性磷酸酶染色和茜素红染色,Western blot检测Runt相关转录因子2的蛋白表达水平;应用生物信息学技术预测和双荧光素酶结合实验验证与Lin28A有关的let-7家族成员之间的相关关系,并通过成骨诱导培养差异表达Lin28A的牙周膜干细胞,测定细胞成骨分化过程中表达变化最明显的miRNA。结果与结论:(1)Lin28A富集在牙周膜干细胞的细胞核中,且在成骨诱导不同时间后呈表达上升的趋势;(2)与空白对照组比较,在过表达Lin28A的牙周膜干细胞模型中,碱性磷酸酶染色和茜素红染色相较空白对照组明显深染,成骨基因碱性磷酸酶、Runt相关转录因子2及骨桥蛋白的表达量分别增加3.3倍、5.1倍及2.2倍(P<0.01);干扰Lin28A表达的细胞模型中,碱性磷酸酶染色和茜素红染色相较对照组染色减少,成骨基因碱性磷酸酶、Runt相关转录因子2及骨桥蛋白的表达量分别下降19%,61%及10%(P<0.01);(3)成骨相关转录因子Runt相关转录因子2的蛋白表达水平与mRNA的差异趋势一致,过表达组呈上升趋势,干扰组呈下降趋势;(4)生物信息学预测出与Lin28A相关的let-7家族成员有8个,分别为let-7a、let-7b、let-7c、let-7d、let-7e、let-7f、let-7g和let-7i,经正常培养和成骨诱导培养筛选发现let-7a和let-7c随Lin28A的表达差异而发生明显的变化,以let-7a的表达趋势最显著;双荧光素酶结合实验也证实let-7a与Lin28A的3’-UTR直接结合,参与影响牙周膜干细胞的成骨分化过程;(5)结果提示:Lin28A参与调控牙周膜干细胞成骨分化,呈正性相关,即过表达Lin28A使牙周膜干细胞成骨能力增强,干扰Lin28A表达后牙周膜干细胞成骨能力减弱;牙周膜干细胞成骨分化受到Lin28A的调控影响。

Lentivirus-mediated shRNA interference targeting STAT3 inhibits human pancreatic cancer cell invasion

AIM： To investigate RNA interference targeting signal transducer and activator of transcription-3 （STAT3） on invasion of human pancreatic cancer cells.METHODS： We constructed three plasmids of RNA interference targeting the STAT3 gene. After LV （lentivirus）-STAT3siRNA （STAT3 small interfering RNA） the vector was transfected into the human pancreatic cell line, SW1990 and cell proliferation was measured by the MTT assay. Flow cytometry was used to assess cell cycle. Vascular endothelial growth favor （VEGF） and matrix metalloproteinase-2 （MMP-2） mRNA and protein expression were examined by quantitative PCR and western blotting, respectively. The invasion ability of SW1990 cells was determined by cell invasion assay.RESULTS： We successfully constructed the LVSTAT3siRNA lentivirus vector and proved that it can suppress expression of STAT3 gene in SW1990 cells. RNA interference of STAT3 by the LV-STAT3siRNA construct significantly inhibited the growth of SW1990 cells, in addition to significantly decreasing both VEGF and MMP-2 mRNA and protein expression. Moreover, suppression of STAT3 by LV-STAT3siRNA decreased the invasion ability of SW1990 cells.CONCLUSION： The STAT3 signaling pathway may provide a novel therapeutic target for the treatment of pancreatic cancer since it inhibits the invasion ability of pancreatic cancer cells.

RNA interference and its application in plants

RNA interference （RNAi）, a process that inhibits gene expression by the double-stranded RNA （dsRNA）, causes the degradation of target messenger RNA molecules. RNAi exists in almost all organisms. We review the recent history of RNAi studies, RNAi molecular mechanisms, characteristics and RNAi applications in higher plants. At the same time, the prospect of RNAi applications in functional genomics and genetic improvement of higher plants and possible future problems and possibilities are also discussed.

The inhibitory effects of siRNA expression vector on CXCR4 expression in prostate carcinoma cell lines

Objective： To investigate the inhibitory effects of RNAi （ RNA interference, RNAi） expression vector on CXCR4 expression in prostate carcinoma cell lines. Methods： Small interference RNA （siRNA） expression vectors for CXCR4 gene were constructed and transfected into prostate carcinoma cell lines（PC-3m and LNCaP）with liposomes. T expression of CXCR4 was detected by RT-PCR and western blot. Results： T expression of CXCR4 mRNA and protein in the PC-3m and LNCaP cells was reduced by RNAi expression vectors. The inhibitory rate of CXCR4 mRNA expression in the PC-3m cells was 87.81% ± 10.20% ,56.10% ± 9.32% at the 24th hour and the 48th hour, compared with 56.93% ±8.78% ,49.24% ± 11.23% in LNCaP cells. The inhibitory rate of the expression of CXCR4 protein was 64.71% ± 6.68% ,58.66% ± 11.56% respectively. Conclusion： The expression of CXCR4 gene can effectively be inhibited by RNAi expression vectors.

MicroRNA-regulated viral vectors for gene therapy

Safe and effective gene therapy approaches require targeted tissue-specific transfer of a therapeutic transgene.Besides traditional approaches, such as transcriptional and transductional targeting, micro RNA-dependent posttranscriptional suppression of transgene expression has been emerging as powerful new technology to increase the specificity of vector-mediated transgene expression. Micro RNAs are small non-coding RNAs and often expressed in a tissue-, lineage-, activation- or differentiation-specific pattern. They typically regulate gene expression by binding to imperfectly complementary sequences in the 3' untranslated region(UTR) of the m RNA. To control exogenous transgene expression, tandem repeats of artificial micro RNA target sites are usually incorporated into the 3' UTR of the transgene expression cassette, leading to subsequent degradation of transgene m RNA in cel s expressing the corresponding micro RNA. This targeting strategy, first shown for lentiviral vectors in antigen presenting cells, has now been used for tissue-specific expression of vector-encoded therapeutic transgenes, to reduce immune response against the transgene, to control virus tropism for oncolytic virotherapy, to increase safety of live attenuated virus vaccines and to identify and select cell subsets for pluripotent stem cell therapies, respectively. This review provides an introduction into the technical mechanism underlying micro RNA-regulation, highlights new developments in this field and gives an overview of applications of micro RNA-regulated viral vectors for cardiac, suicide gene cancer and hematopoietic stem cell therapy, as well as for treatment of neurological and eye diseases.

Non-viral gene carrier mediated short hairpin RNA interference for inhibition of tumor cells growth

A tumor-targeting gene vector G250mAb-PEI-PEG has been prepared by modification of polyethylenimine (PEI) with polyethyleneglycol (PEG) and G250, a monoclonal antibody against the G250 antigen on tumor cell surface. The transfection efficiency was as high as 70% in G250 positive HeLa cells, whereas the transfection efficiency was relatively low (30%) in normal NIH3T3 cells. A plasmid encoding the short hairpin RNA (shRNA) specific for nucleostemin gene (NS) was efficiently transfected into the HeLa cells with this nonviral gene vector. RNA interference down-regulated the expression of NS gene in HeLa cells, inhibited cells proliferation and induced apoptosis. However, the growth and activity of the NIH3T3 cells were not affected under the same treatment. These results indicate that the reported nonviral gene vector, G250mAb-PEI-PEG, can target and efficiently deliver genes into HeLa cells, and has the potential for the cervical cancer treatment.

In vivo Inhibitory Effect of Lentivirus-mediated RNA Interference Targeting RhoC on Growth of SKOV3 Cells

To investigate the inhibitory effect of lentivirus-mendiated RNA interference targeting RhoC on the growth of SKOV3 cells（ovarian cancer SKOV3 cells） in vivo, the vector expressing RNA interference targeting RhoC gene（LV-shRhoC） was constructed and the virus particles were packaged. The infection effiency of SKOV3 cells by the virus was estimated by green fluorescent protein expression on a fluorescence microscope and the expression of RhoC gene in the SKOV3 cells was detected by reverse transcription real time polymerase chain reaction（PCR）. Furthermore, human ovarian cancer SKOV3 cells, empty vector infected SKOV3 cells and interfered-vector infected SKOV3 cells were respectively seeded into nude mice, and the shape, mass, volume and histophathological changes of the transplanted tumors were observed 20 d later the mice were sacrified. The results show that lentivirus packa-ging particles can effectively infect SKOV3 cells and the lentivirus-mediated RNA interference can significantly in- hibit the expression of RhoC gene in SKOV3 ceils, the mass and volume of the transplanted tumor in the mice of the specific-control group（Lv-shRhoC） are all lower than the corresponding ones in the mice of negative- and blank-control groups（Lv-NC and SKOV3）. Moreover, the histopathlosical secion investigation shows that the nuclear Karyotype and histopathologic mitotic figure of SKOV3 cells in mice of the specific-control group are clearly lower than those in the mice of the negative-control group.Thus it is concluded that silencing RhoC gene by means of lenti- virus-mediated RNA interference targeting RhoC can obviously inhibit the growth of ovarian cancer cells（SKOV3） in vivo, which is a new strategy for the gene therapy of ovarian cancers.

和田羊FGF5基因RNA干扰载体构建及筛选

试验旨在构建并筛选出高效的和田羊成纤维细胞生长因子5(FGF5)基因的RNA干扰载体,根据和田羊FGF5基因序列,设计4条短发夹RNA(shRNA)干扰片段和1条阴性对照片段。扩增后克隆至pGPU6载体,获得4个重组质粒pGPU6-shRNA-FGF1、pGPU6-shRNA-FGF2、pGPU6-shRNA-FGF3、pGPU6-shRNAFGF4和阴性对照质粒pGPU6-shRNA-FGF5。通过琼脂糖凝胶电泳和DNA测序对质粒进行酶切鉴定和测序鉴定。鉴定后的质粒通过电刺激法转染至和田羊成纤维细胞,通过qRT-PCR和Western Blotting(WB)分析FGF5基因的表达情况。结果显示,与阴性载体相比,4个RNA干扰表达载体均可显著降低FGF5 mRNA和蛋白的表达量(P<0.05),其中pGPU6-shRNA-FGF3干扰效率最高,为85.20%。研究表明,FGF5干扰表达载体构建成功并可有效干扰和田羊FGF5基因表达。

The Comparative and Functional Study between Two Construction Methods of shRNA Expression Vector Targeted LMP1 Gene Encoded by EBV

To look for a more stable and convenient way of constructing short hairpin RNA expression vectors targeting the latent membrane protein-1(LMP-1)encoded by Epstein-Barr virus(pshLMP1),and to study the inhibition function of pshLMP1 expression vectors in HNE1 cells,we designed the pshLMP1 expression cassette and pshLMP1 expression vectors by both the annealing method and PCR method and then co-transfected with pEGFP-N1-1158 into HNE1 cells to observe the mRNA and protein levels of LMP-1 genes by green fluorescence analysis,RT-PCR and western blot.pshLMP1 expression vectors were successfully obtained by both methods but better cloning efficiency was achieved and fewer deletions and mutations of nucleotides were achieved with the PCR method.Furthermore,the mRNA and protein levels of LMP-1 genes were down-regulated by pshLMP1 expression vectors.According to our research,we found that the PCR method provides a more efficient way to construct pshLMP1 expression vectors which have the ability to inhibit the function of LMP-1 genes expressed in HNE1 cells,and also provides a novel application of RNA interference technology against-EBV.

STUB1基因RNA干扰慢病毒载体的构建与鉴定

目的:构建人STUB1基因RNA干扰(RNA interference,RNAi)慢病毒表达载体并进行鉴定。方法:针对筛选确定的人STUB1基因RNAi有效靶点序列,合成靶序列的Oligo DNA,退火形成双链DNA,与经AgeI和EcoRI酶切后的pMagic 4.0载体连接,产生短发卡RNA慢病毒载体。PCR筛选阳性克隆,测序鉴定,并包装成慢病毒颗粒。结果:PCR鉴定与DNA测序证实,合成的含STUB1 shRNA慢病毒载体寡核苷酸链插入正确。STUB1 shRNA慢病毒载体在293T细胞中成功包装成慢病毒颗粒。结论:成功构建人STUB1基因RNAi慢病毒载体以及包装成功慢病毒颗粒,为研究STUB1在胶质瘤发生发展过程中相关信号通路的作用,提供了稳定感染细胞的载体。

pRNAT-U6.1/Neo系统在E2F-3基因RNA干扰载体构建中的应用

目的:构建针对E2F-3基因的siRNA表达载体。方法:化学合成3对编码短发夹RNA序列的、靶向E2F-3基因的寡核苷酸链,各64个碱基,退火、克隆到经BamHI、HindⅢ双酶切的pRNAT-U6.1/Neo载体上,重组构建RNAi质粒。通过双酶切、PCR鉴定及基因片段序列分析验证构建效果。结果:重组构建的pRNAT-U6.1/Neo载体经PCR分析及插入基因片段序列分析,结果表明64个碱基成功插入到预计位点,并且序列完全一致,插入序列无点突变位点。结论:载体的成功构建为进一步研究E2F-3基因在膀胱肿瘤中的作用奠定了基础,为进一步以其为靶点进行膀胱癌细胞系体外实验创造了条件。

RNA干涉培育低木质素杨树

采用改良的CTAB法提取南林95杨的基因组DNA,经PCR扩增得到肉桂酰辅酶A还原酶CCR基因的第4个外显子部分序列,通过中间载体pUCCRNAi,构建含正反向干涉片段的pBI121表达载体,导入农杆菌LBA4404。利用叶盘法侵染南林95杨,获得3株转基因植株,经分子鉴定证实干涉片段已导入南林95杨。测定Klason木质素及综纤维素含量的结果显示:转基因植株Klason木质素含量与对照相比平均降低了9.86%,综纤维素含量与对照相比平均增加了3.17%,纤维长宽比明显增加,均表明转基因植株更有利于造纸。

人Notch4基因RNAi慢病毒载体的构建及鉴定

目的涎腺腺样囊性癌(salivary adenoid cystic carcinoma,SACC)是涎腺常见的恶性肿瘤,Notch4基因与SACC的发生、转移有关。文中构建人Notch4基因RNA干扰(RNA interference,RNAi)慢病毒载体并鉴定。方法针对人Notch4基因序列,按照RNAi序列设计原则,设计RNAi靶点序列,通过限制性内切酶MIu l和CIa l双酶切、T4 DNA连接酶连接,将Notch4插入慢病毒载体pLenOR-THM,构建pLenOR-THM-Notch4重组载体。质粒转化感受态细菌,筛选阳性克隆,经双酶切及测序鉴定正确后通过脂质体将慢病毒4质粒系统共转染293 T细胞,进行慢病毒包装并测定病毒滴度、观察感染效率。各组病毒载体转染ACC-M细胞后,用QRT-PCR和Western blot检测Notch4基因mRNA和蛋白的表达水平。结果成功构建慢病毒表达载体pLenOR-THM-Notch4,4质粒共转染293T细胞后可见大量绿色荧光。浓缩病毒后测定其滴度为6.2×108TU/ml。以复感染系数MOI(multiplicity of infection)为1感染293T细胞,感染效率在90%以上。结合QRT-PCR和Western blot检测结果,第2组慢病毒载体干扰效果最佳。结论成功构建并鉴定人Notch4 RNAi慢病毒表达载体。