人PDLIM4基因启动子报告基因载体的构建及其在人类肿瘤细胞中的表达

目的构建人PDLIM4基因启动子荧光素酶报告基因重组质粒pGL3-promoter,检测其在不同肿瘤细胞中的表达。方法据Genebank中人PDLIM4基因启动子序列分别设计上下游引物,扩增其启动子片段,并插入到pGL3-Basic报告基因载体,分别得到含有3kb和1.2kb的PDLIM4基因启动子的两个报告基因质粒pGL3-PD-LIM4-3kb和pGL3-PDLIM4-1.2kb。序列为1.2kb的启动子利用Erase-a-base试剂盒,经外切酶Ⅲ从5’端逐步酶切得到5个含不同长度启动子序列的报告基因载体:pGL3-PDLIM4-1.2D1、pGL3-PDLIM4-1.2D2、pGL3-PDLIM4-1.2D3、pGL3-PDLIM4-1.2D4、pGL3-PDLIM4-1.2D5。将构建的报告基因载体分别瞬时转染以下细胞株:Hela、MDA-MB231、KB、PC-3、LNCaP,检测其荧光素酶表达活性。结果所构建质粒经酶切、测序鉴定,其片段长度及序列均正确。转染结果显示,长片段的3kb和1.2kb启动子序列在所测试的细胞株中均有表达,但在人激素非依赖前列腺癌PC-3细胞株、人激素依赖前列腺癌LINCaP细胞株中表达较低。而不同长度的启动子报告基因质粒转染PC-3、LNCaP的结果显示,pGL3-PDLIM4-1.2kb表达活性最强,pGL3-PDLIM4-970bp表达活性最弱。结论成功构建了7个分别含有不同长度的PDLIM4启动子报告基因载体,其在不同的肿瘤细胞株中均有不同程度的表达,而在前列腺癌细胞中表达较低。     

Inhibition of hepatitis C virus core and NS3protein expression by siRNA

Objective To construct two kinds of plasmids with one for gene expression and the other for RNA expression. Methods Hepatitis C virus(HCV)core and NS3 genes were firstly inserted into the upstream of the reporter genes marked with Rellina(hRluc)luciferase and Firefly luciferase(hluc+).And then the established Plasmids were cotransfected into HEK293 cells. Six short hairpin RNAs targeted HCV core and NS3 genes were designed. and expressed by siRNA expression vector. Inhibition effects with the luminescent intensity were observed. Results Light density in the cells cotransfected with core gene and anti-Core siRNA was obviously weaker, meanwhile. those with NS3 gene and anti-NS3 siRNA had no difference in contrast with the control group. Transfected the anti-NS3 siRNA into the stable expression cells and detected them by real-time PCR and western-blot. The four siRNAs have efficiently suppressed the expression of NS3 at some level. Conclusion The results demonstrated that siRNA Was effective in inhibiting HCV protein expression,and may have therapeutic potential to limit HCV replication in chronically infected patients.     

RhoE对cd44基因启动子的转录活性及大肠癌细胞系恶性生物学行为的影响

目的研究RhoE对cd44基因启动子的转录调控,并探讨RhoE对裸鼠体内成瘤性的影响。方法采用PCR技术从人胚肾HEK293细胞中扩增出cd44启动子,并将其插入荧光素酶报告基因载体pGL3-Basic中,经测序确定所扩增的DNA序列,并将其转染入SW480及LoVo细胞中监测其活性。将pcDNA3.1-RhoE和pcDNA3.1分别与pGL3-CD44 promoter共转染大肠癌LoVo细胞和SW480细胞,双荧光素报告基因检测活性。另外将pcDNA3.1-RhoE和对照组分别稳定转染LoVo细胞和SW480细胞,并将筛选的稳定表达的细胞分别接种裸鼠,观察肿瘤的生长;用免疫组化的方法检测RhoE对肿瘤组织细胞形态及CD44分子表达的影响。结果测序结果表明,扩增的cd44启动子序列正确,双报告基因实验检测荧光素酶活力表明构建的报告基因具有启动子活性。含cd44启动子序列的报告基因在pcDNA3.1-RhoE阳性的LoVo细胞中表达受到抑制;HE染色显示pcDNA3.1-RhoE转染组较对照组肿瘤细胞明显变小,且大小和形态呈现一致性,已没有瘤巨细胞,相应的肿瘤细胞核的体积也变小。结论 RhoE通过抑制cd44...     

人类免疫缺陷病毒假病毒检测系统的构建

目的构建人类免疫缺陷病毒(HIV)感染性克隆并在此基础上建立携带荧光素酶基因(Luc+)的HIV假病毒感染系统。方法利用长片段PCR技术分别扩增福建省HIV分离株LWJ前后半长基因序列,以pCR-XL-TOPO为载体构建HIV感染性克隆pLWJ。将Luc+表达基因片段替换感染性克隆pLWJ中部分env区序列,从而构建出携带Luc+基因的报告基因病毒载体pLWJ-SV40-Luc+。将报告基因病毒载体和膜蛋白表达质粒VSV-G共转染293T细胞,获得携带Luc+基因的HIV假病毒。将HIV假病毒感染293T细胞,利用化学发光法检测感染细胞中Luc+相对荧光单位(RLU)。结果以HIV感染性克隆pLWJ为基础,构建出携带荧光素酶基因的VSV-G/HIV假病毒感染系统,其所产生的VSV-G/HIV假病毒仅有单轮感染活性,被感染细胞中报告基因的表达水平与加入病毒量呈剂量依赖性关系。结论成功建立具有单轮感染活性的VSV-G/HIV假病毒检测系统,为开展HIV相关基础研究提供一个技术平台。     

雌激素受体Arg548／Cys548基因突变导致受体的高敏感性

目的：研究雌激素受体新突变Arg548／Cys548对受体介导的下游基因表达调控的影响,并探讨其机理和在女孩性早熟中的作用。方法：利用已构建的雌激素受体反应元件报道质粒pGL3-promoter-ERE,分别与野生型ESR1表达质粒PsG5-wtER和定点突变受体表达质粒PSG5-mutER共转染cMF-7和MDA—MB-231细胞,转染后加入雌激素、类似物和拮抗物处理,检测转染细胞的荧光素酶活性值。结果：转染突变型受体的CMF-7和MDA-MB-231细胞的荧光素酶活性值明显升高,在生理浓度雌激素及类似物植物类雌激素异黄酮刺激下,Cys548突变型受体基因转染比野生型受体转染的CMF-7和MDA231细胞均表现出显著强烈的增加萤火虫荧光素酶的活性,表现高敏感的特性;单独加入TAM后荧光素酶活性值没有变化,而同时加入E2和TAM后荧光素酶活性值比加入E2的荧光素酶活性值则明显下降。结论：Cys548突变受体在体外具有较高的敏感性,对药物雌二醇及类似物反应敏感,拮抗剂TAM对受体的活性没有抑制作用,却能竞争性降低雌激素及类似物的作用。     

microRNA调控NK细胞KIR3DL1表达初探

目的初步探寻人外周血自然杀伤细胞（Nature Killer,NK）杀伤细胞免疫球蛋白样受体（Killer Cell Immnoglobulin-Like Receptor,KIR3DL1）表达可能存在的microRNA（miR）调控机制。方法利用生物信息学方法,从miR信息库中筛选出可能与KIR3DL1相关的miRs,构建含KIR3DL1 3’非翻译区（UTR）的PGL3质粒,分别将含相应miR的PcDNA3.0质粒与前者共转染293T细胞,通过荧光素酶报告实验及之后的突变实验筛选出可能调控KIR3DL1的miR。结果通过TARGET SCAN信息库筛选了miR-146b等10个miR;转染miR-146b后,荧光素酶活性下降最多（61.3%）,突变其KIR3DL1 3’UTR靶位点后荧光素酶活性恢复（91.4%）。结论 miR-146b可与KIR3DL1’UTR在靶位点特异结合,很可能参与KIR3DL1表达的调控。     

P53对涎腺腺样囊性癌细胞端粒酶活性的抑制作用

目的为了探讨P53基因对腺样囊性癌细胞端粒酶活性的抑制作用及机制。方法构建携带人野生型P53基因的腺病毒表达载体，以脂质体法瞬时转染腺样囊性癌SACC-83细胞，RT-PCR检测转染细胞P53基因mRNA的表达，TRAP-PCR-ELISA法检测转染细胞端粒酶活性的改变。并将P53基因与含有hTERT启动子核心调控区的荧光素酶报告基因pGL2—630共转染SACC-83细胞，测定转染细胞荧光素酶报告基因活性。结果1．瞬时转染含人野生型P53基因的重组腺病毒表达载体p△E1-P53于腺样囊性癌SACC-83细胞后，其P53基因mRNA的表达明显增强；2．基因转染后，SACC-83细胞内源性端粒酶活性显著降低。3．P53基因与含有hTERT启动子核心调控区的荧光素酶报告基因pGL2-630共转染SACC-83细胞后，其荧光素酶活性显著下降。结论外源性表达P53基因可以降低腺样囊性癌细胞SACC-83细胞端粒酶活性，并可能通过抑制端粒酶hTERT基因启动子的转录活性实现。     

丙型肝炎病毒与荧光素酶融合基因细胞模型的初步建立

Objective　To establish HCV cell culture model which is easy to measure. Methods　Controllable retroviral vector with fusion gene of hepatitis C virus (HCV) cDNA and luciferase (luc) reporter gene was constructed by molecular cloning technique, the transfection of this retroviral vector in a human hepatic carcinoma cell (HHCC) line was performed by lipofectAMINE and then luciferase activity in the cellular lysate was measured by scintillation counter. Results　 ① Fusion gene of the HCV 5′ NCR-C region and luciferase reporter gene identified by restriction endonuclease cleavage have been cloned into pBPSTR1 vector. ② The luciferase activity could maintain up to 20 days at least, and could be increased by puromycin treatment and regulated by tetracycline. Conclusion　A cell model for expression of HCV C-E1 and luciferase genes was established for gene therapy studies against HCV C-E1 sequences.     

Effect of structural domain Ⅱ of HCV 5' noncoding region on its translation initiation activity

Objective To examine the role of domain Ⅱ of hepatitis C virus(HCV) 5'noncoding region (5'NCR) in its translation initiation activity. Methods The fragment of HCV 5' NCR with deletions of 5'-proximal 118 nucleotides were amplified with PCR, then was used to substitute for the full length HCV 5'NCR of plasmid pCMVNCRIuc, a firefly luciferase(Flue) eukaryotic expression plasmid regulated by HCV 5' NCR, to generate recombinant plasmid pCN1-d3, pCMVNCRIuc, pCN1-d2 (modified pCMVNCRluc with deletions of HCV 5' NCR nt1-43) and pCN1-d3 were transfected into HepG2 cells with liposome transfection protocol, respectively, and the relative luciferase activity was measured to analyze the regulatory effect of the truncated 5'NCR on Fluc gene expression. Meanwhile the Fluc mRNA levels were detected by RT-PCR. Results The recombinant plasmid was successfully constructed. The Fluc mRNA levels of the 3 plasmids were not significantly different(P 0.05), and there were also no significant difference between the relative luciferase activity of plasmids pCN1-d2 and pCMVNCRluc(P 0.05). However, that of pCN1-d3 was decreased significantly(P < 0.01, compared with pCN1-d2 or pCMVNCRluc). Conclusion Structural domain Ⅱ of HCV 5' NCR plays an important role in itstranslation initiation activity.