Bcl-XL小发夹RNA腺病毒载体的构建及其抗肿瘤作用

目的:构建表达Bcl-XL小发夹RNA的腺病毒载体(Ad/Bcl-XL shRNA)并探讨其抗肿瘤作用。方法:构建、纯化重组腺病毒Ad/Bcl-XL shRNA。通过Western blotting、MTT分析验证它对Bcl-XL的下调及其杀伤肿瘤细胞的作用,并检测其处理后细胞凋亡信号的活化情况;在裸鼠皮下荷瘤模型中验证其体内抗肿瘤作用。结果:成功构建和纯化了Ad/Bcl-XLshRNA,它能显著下调结肠癌DLD1细胞Bcl-XL蛋白的表达;与Ad/GFP、PBS组相比,Ad/Bcl-XL shRNA组明显抑制人结肠癌细胞DLD1的生长[1 000 MOI时(60.6±4.8)%vs(99.0±2.6)%、100%;2 000 MOI时,(37.3±6.9)%vs(99.0±2.1)%、100%,P<0.01],但对正常人成纤维细胞无明显抑制作用(P>0.05);Ad/Bcl-XL shRNA组能有效诱导结肠癌细胞中凋亡信号casepase-9、casepase-3、PARP的活化。在裸鼠荷瘤模型中,与Ad/GFP、PBS组相比,Ad/Bcl-XL shRNA组显著抑制DLD1来源皮下肿瘤的生长[第29天时,(250.1±185.7)vs(880.0±286.1)、(911.0±389.1)mm3;P<0.01]。结论:Ad/Bcl-XLshRNA能显著抑制结肠癌细胞在体内外的生长,其在结肠癌治疗中具有潜在的应用价值。     

靶向VEGF发夹状RNA对宫颈癌HeLa细胞抑制作用的研究

目的:运用RNAi技术下调血管内皮生长因子(VEGF)在HeLa细胞中的表达,观察其对肿瘤细胞凋亡的影响,为人宫颈癌治疗提供理论依据。方法:设计并构建针对VEGF的携带绿色荧光蛋白(GFP)发夹状RNA(shRNA)质粒表达载体(PGPU6/GFP/Neo-shRNA),脂质体法转染HeLa细胞;荧光显微镜观察GFP的表达,并计算转染效率;RT-PCR检测HeLa细胞VEGF的表达,筛选出靶序列;再用流式细胞仪法检测细胞凋亡。结果:构建的PGPU6/GFP/Neo载体成功转入HeLa细胞;转染48h后,HeLa-shVEGF1组HeLa细胞VEGFmRNA表达的抑制率为75.0%;与HeLa组和HeLa-shNC组相比,HeLa-shVEGF1组HeLa细胞凋亡率明显增加,P<0.01。结论:本研究构建的PGPU6-shRNA表达载体携带GFP便于观察细胞的转染情况,且不影响U6启动子的转录,同时有效沉默了VEGF基因,明显增加HeLa细胞的凋亡,为未来肿瘤的治疗提供新途径。     

A small interfering RNA targeting osteopontin as gastric cancer therapeutics

It has been shown that Osteopontin (OPN) protein is overexpressed in the majority of gastric cancers and associated with its pathogenesis. To better understanding of the role of OPN, RNA interference (RNAi) was used to inhibit OPN expression in the human gastric cancer cells in vitro and in vivo. BGC-823, gastric cancer cell line, was stably transfected with OPN small interfering RNA (siRNA) plasmids. OPN siRNA significantly reduced the expression of OPN in human gastric cancer cells in transient- and stable-transfection manner. In vitro down-regulation of OPN inhibited BGC-823 cell growth, anchorage-independent growth, migration and invasion. The results further showed that OPN small interfering RNA suppressed the growth, migration and invasion of gastric cancer cell through the reduction of MMP-2 and uPA expression, inhibition of NF-kappaB DNA binding activity, and down-regulation of Akt phosphorylation. In vivo animal studies showed that tumor growth was significantly inhibited in OPN siRNA group compared with WT. Intratumor gene therapy with polyethylenimine/OPNsi also resulted in tumor growth suppression and prolonged survival. Thus, this study demonstrated that down-regulation of OPN could suppress the growth, migration and invasion of gastric cancer cells, and OPN siRNA may offer a new potential gene therapy approach for human gastric cancer in future.     

Ezrin silencing by small hairpin RNA reverses metastatic behaviors of human breast cancer cells

Ezrin primarily acts as a linker between the plasma membrane and the cytoskeleton and is a key component in tumor metastasis. In the present study, RNA interference (RNAi) using ezrin small hairpin RNAs (ezrin shRNAs) was used to define the roles of ezrin in the regulation of malignant behaviors of human breast cancer. The highly metastatic human breast cancer cell MDA-MB-231, in which ezrin mRNA and protein levels are the highest, was selected as a cell model in vitro. In addition, we also found that ezrin expression was up-regulated and its immuno-staining trans-located from cell membrane to cytoplasm, whereas E-cadherin expression decreased and showed the same cell distribution as ezrin in lymphatic metastases of human breast carcinomas. After repression of ezrin by more than 85% of G3PDH and 75% of beta-actin in mRNA and protein levels was maintained in the stable expressing ezrin shRNAs MDA-MB-231 cell clones, the abilities of cell motility and invasiveness were obviously inhibited with a 4-fold and 2-fold, respectively, and the altered cell polarity was observed. Western blot analyses further revealed that the silencing of ezrin induced an increased E-cadherin expression and a decreased phosphorylation of beta-catenin by inhibiting phosphorylation levels of c-src. These data indicate that ezrin overexpression positively correlated with metastatic potentials of human breast cancer cells, especially lymphatic system metastasis. Decreased ezrin expression by shRNA reversed metastatic behaviors of human breast cancer cells by inducing c-src-mediated E-cadherin expression, suggesting that ezrin may have potential values in assessing lymphatic metastasis of human breast cancers.     

Functional screening identifies a microRNA,miR‐491 that induces apoptosis by targeting Bcl‐XL in colorectal cancer cells

MicroRNAs (miRNAs) are a class of small noncoding RNAs that negatively regulate expression of target mRNA. They are involved in many biological processes, including cell proliferation, apoptosis and differentiation, and considered as new therapeutic targets for cancers. In our study, we performed a gain‐of‐function screen using 319 miRNAs to identify those affecting cell proliferation and death in human colorectal cancer cells (DLD‐1). We discovered a number of miRNAs that increased or decreased cell viability in DLD‐1. They included known oncogenic miRNAs such as miR‐372 and miR‐373, and tumor suppressive miRNAs such as miR‐124a, but also some for which this information was novel. Among them, miR‐491 markedly decreased cell viability by inducing apoptosis. We demonstrated that Bcl‐X_L was a direct target of miR‐491, and its silencing contributed to miR‐491‐induced apoptosis. Moreover, treatment of miR‐491 suppressed in vivo tumor growth of DLD‐1 in nude mice. Our study provides a new regulation of Bcl‐X_L by miR‐491 in colorectal cancer cells, and suggests a therapeutic potential of miRNAs for treating colorectal cancer by targeting Bcl‐X_L.     

The study of RNAi-mediated by conditionally replicating adenovirus silencing on Survivin gene in colon cancer cell lastingly

Objective: To investigate the effect of RNAi-mediated Survivin gene with conditionally replicating adenovirus silencing on Survivin gene in colon carcinoma cell lines HT-29 lastingly.Methods: We transfected Ad-delElb55KD-shRNA/ Survivin-EGFP to HT-29 (control was replication defective adenovirus and liposome vector which was contained the same shRNA as Ad-delE1b55KD-shRNA/Survivin-EGFP).The expressions of EGFP, Survivin mRNA and Survivin protein in HT29 were detected at the 1st, 7th, 14th and 28th days after transfection.Results: The expression of EGFP, the inhibition of Survivin mRNA and Survivin protein in HT-29 were high in each group at the 7th day after transfection, among the total, the effect of Ad-delE1b55KD-shRNA/Survivin-EGFP group was the highest; at the 14th day, the effects of replication defective adenovirus group and liposome vector group were decreased obviously, and it was still high in Ad-delE1b55KD-shRNA/Survivin-EGFP group; at the 28th day, the effects of control groups were disappeared, and it was still high in Ad-delE1b55KDshRNA / Survivin-EGFP group like before (P＜0.05).Conclusion: RNAi-mediated Survivin gene with conditionally replicating adenovirus can silence Survivin gene in colon carcinoma call lines HT-29 lastingly.     

siRNA沉默livin的表达对人结肠癌HT-29细胞增殖、凋亡及侵袭的影响

目的:探讨小干扰RNA(small interference RNA,siRNA)沉默人结肠癌HT-29细胞livin表达对HT-29细胞增殖、凋亡和侵袭的影响。方法:合成靶向livin的双链siRNA(livin-siRNA),转染HT-29细胞,RT-PCR及Western blotting检测HT-29细胞中livin mRNA及蛋白的表达,MTT实验检测HT-29细胞的增殖,流式细胞术检测HT-29细胞周期分布及凋亡,细胞侵袭实验检测HT-29细胞侵袭性的变化,caspase-3活性检测试剂盒检测caspase-3活性的变化。结果:Livin-siRNA转染后48 h,与空白组、阴性对照组及脂质体组相比,livin-siRNA转染组HT-29细胞中livin mRNA水平明显下降(0.073±0.007 vs 0.395±0.082、0.423±0.025、0.418±0.032,P<0.05),其蛋白表达也明显下调(0.106±0.003 vs 0.456±0.065、0.473±0.078、0.491±0.045,P<0.05)。转染96 h后,livin-siRNA组HT-29细胞增殖能力明显低于对照组及脂质体组(0.564±0.102 vs0.833±0.127、0.860±0.153,P<0.05),且细胞凋亡率升高[(16.5±2.8)%vs(2.4±0.5)%、(3.7±1.0)%,P<0.05]。侵袭实验显示,livin-siRNA转染后,穿过Matrigel膜的HT-29细胞数量明显少于对照组及脂质体组[(31.3±4.5)vs(101.3±8.6)、(97.4±7.8)个,P<0.05)]。livin-siRNA组HT-29细胞的caspase-3活性低于对照组(0.160±0.023 vs 0.347±0.058,P<0.05)。结论:siRNA沉默livin的表达可抑制HT-29细胞的增殖,诱导细胞凋亡,抑制细胞的侵袭。     

靶向人Pokemon基因的shRNA重组质粒的构建(英文)

Objective:The aim of this study was to establish the foundation for studying the role of pokemon gene in tumorigenesis and development by constructing recombinant plasmids that can express small interfering RNA(siRNA)targeting human Pokemon gene.Methods:Hairpin siRNA templates targeting Pokemon gene were synthesized and cloned into plasmid vector psiRNA-H1neo.Three vectors derived siRNAs(psiRNA1,2,3)and one mocking psiRNAc(as control)were con- structed.The recombinant Pokemon siRNA plasmids were constructed...     

Pinocembrin triggers Bax-dependent mitochondrial apoptosis in colon cancer cells

Bioflavanoids are the major pigments in plants with multitude of biological activities including inhibition of proliferation or induction of apoptosis in tumor cells. Even though the safety records of most flavanoids are exceptional, its therapeutic use is still in its infancy. We have isolated pinocembrin (5,7-dihydroxyflavanone) from Alpinia galanga that showed cytotoxicity against a variety of cancer cells including normal lung fibroblasts with relative nontoxicity to human umbilical cord endothelial cells. The compound induced loss of mitochondrial membrane potential with subsequent release of cytochrome c and processing of caspase-9 and -3 in colon cancer cell line HCT 116. Processing of caspase-8 was minimal. The initial trigger for mitochondrial apoptosis appears to be by the translocation of cytosolic Bax protein to mitochondria. Overexpression of proapoptotic Bax protein sensitized the colon cancer cells to pinocembrin-induced apoptosis and Bax knockout cells were resistant to pinocembrin-induced apoptosis. Antiapoptotic protein Bcl-X(L) only partially prevented apoptosis induced by this compound. The Bax-dependent cell death involving classical cytochrome c release and processing of caspase-9 and -3 suggests that pinocembrin is a classical mitochondrial apoptosis inducer. But the failure of Bcl-X(L) overexpression to completely prevent apoptosis induced by this compound suggests that pinocembrin is capable of triggering mitochondrial-independent cell death that needs to be clarified. The existence of cell death upon Bcl-X(L) overexpression is a promising feature of this compound that can be exploited against drug resistant forms of cancer cells either alone or in combination with other drugs.     

siRNA沉默结肠癌转移相关基因1表达对人类卵巢癌细胞株侵袭转移的影响

目的 检测结肠癌转移相关基因1（MACC1）在卵巢癌细胞株中的表达,并探讨用siRNA技术抑制其表达对卵巢癌细胞生物学行为的影响.方法 应用实时荧光定量PCR （RT-qPCR）及Western blot法检测OVCAR3、ES-2、SKOV3、HO-8910卵巢癌细胞株中MACC1的表达,合成MACC1特异性siRNA并转染OVCAR3细胞,利用RT-qPCR筛选并鉴定MACC 1基因有效沉默后,应用体外黏附实验、Transwell迁移及侵袭实验、体外血管拟态实验检测MACC1基因沉默后OVCAR3细胞的体外黏附、迁移、侵袭及血管生成能力的变化.结果 OVCAR3细胞较其他卵巢癌细胞株高表达MACC1.MACC1基因沉默后,OVCAR3细胞的体外黏附能力受到不同程度的抑制;Transwell迁移实验中,MACC1 siRNA干扰的OVCAR3细胞（干扰组）转入底层膜的细胞数为（245.5±12.8）个,低于阴性对照组和空白对照组[分别为（500.3±16.5）、（496.3±13.1）个,均P＜0.05]; Transwell侵袭实验中,干扰组转入底层膜的细胞数为（185.3±14.1）个,低于阴性对照组和空白对照组[分别为（405.7±9.1）、（416.3±11.5）个,均P＜0.05];体外血管拟态显示干扰组细胞多呈散在分布,连接减少,形成的完整结构少.结论 利用siRNA技术抑制MACC1基因表达可有效抑制卵巢癌OVCAR3细胞的体外转移和侵袭能力,MACC1有望成为卵巢癌治疗的靶基因.     

腺病毒介导的ＢＩＲＣ５-ｓｈＲＮＡ增强索拉非尼诱导肝癌细胞凋亡的研究

目的　研究ＢＩＲＣ５靶向基因治疗联合索拉非尼分子靶向治疗肝癌的协同效应以及对肝癌细胞凋亡的诱导作用。方法　构建ＢＩＲＣ５特异性小发卡ＲＮＡ的腺病毒ＡｄＥＧＦＰ ｓｈＢＩＲＣ５,用免疫细胞化学染色法检测其对ＢＩＲＣ５的沉默作用。建立肝癌移植瘤模型验证ＡｄＥＧＦＰ-ｓｈＢＩＲＣ５联合索拉非尼治疗的疗效,采用免疫组化染色法鉴定ＡｄＥＧＦＰ-ｓｈＢＩＲＣ５对癌细胞ＢＩＲＣ５基因表达的抑制作用;ＴＵＮＥＬ法标记ＡｄＥＧＦＰ-ｓｈＢＩＲＣ５联合索拉非尼诱导肝癌细胞凋亡。结果　腺病毒介导的ＢＩＲＣ５-ｓｈＲＮＡ表达能有效沉默肝癌细胞ＢＩＲＣ５表达,ＡｄＥＧＦＰ-ｓｈＣｔｒｌ对照组的ＢＩＲＣ５阳性表达率为（７８.８±１２.６）％,ＡｄＥＧＦＰ-ｓｈＢＩＲＣ５实验组为（２０.６±８.２）％,两组差异有统计学意义（Ｐ＜０.０１）。Ｈｅｐ３Ｂ裸鼠移植瘤治疗后５周,与空白对照组相比,ＡｄＥＧＦＰ ｓｈＢＩＲＣ５联合索拉非尼组、单用ＡｄＥＧＦＰ ｓｈＢＩＲＣ５组、单用索拉非尼组的抑瘤率分别为６１.７８％（Ｐ＝０.００３２）、４２.３６％（Ｐ＝０.００５９）和２９.２０％（Ｐ＝０.０１６９）;与此对应,ＡｄＥＧＦＰ-ｓｈＢＩＲＣ５联合索拉非尼组与单用索拉非尼组相比,肝癌细胞ＢＩＲＣ５表达被抑制（Ｐ＝０.０３６４）,细胞凋亡比例明显升高（Ｐ＝０.０２９６）。结论　针对ＢＩＲＣ５的基因治疗能提高肝癌细胞对索拉非尼的敏感性,显著诱导癌细胞凋亡。     

shRNA逆转耐阿霉素人乳腺癌细胞株（MCF-7/AdrR）的多药耐药性

目的〖HT5"SS〗： 利用短发夹RNA（short hairpin RNA,shRNA）表达载体逆转耐阿霉素人乳腺癌细胞株(MCF7/AdrR)的多药耐药性（multidrug resistance,MDR）。〖HT5W〗方法〖HT5"SS〗： 构建2个MDR1基因shRNA表达质粒,稳定转染MCF7/AdrR细胞。RTPCR分析MDR1基因mRNA的表达,Western blotting检测P糖蛋白(Pgp)的表达,流式细胞术和MTT法分别检测乳腺癌细胞的凋亡和对阿霉素的敏感     

小干扰RNA靶向MIF对胃癌细胞SGC 7901增殖和凋亡的影响#br#

目的探讨靶向巨噬细胞移动抑制因子（MIF）的小干扰RNA（siRNA）对胃癌细胞SGC 7901增殖和凋亡的影响。 方法取对数生长期的SGC 7901细胞,采用脂质体法分别转染靶向人MIF的siRNA（siMIF组）或阴性对照序列（NC组）,48 h后采用Western blotting检测MIF蛋白的表达情况,MTT法观察转染后24、48、72 h的细胞增殖情况,流式细胞仪检测转染后72 h的细胞凋亡率,Western blotting检测凋亡相关蛋白Bcl 2和Bax的表达变化。 结果siMIF组转染48 h后的MIF相对表达量为0321±0104,低于NC组的1078±0212,差异有统计学意义（P＜005）。siMIF组转染48～72 h后的细胞增殖率低于NC组,差异有统计学意义（P＜005）。转染MIF siRNA 72 h后,siMIF组的细胞凋亡率为（235±36）％,高于NC组的（47±17）％,差异有统计学意义（P＜005）。siMIF组Bcl 2的相对表达量为0663±0209,低于NC组的1129±0178,而Bax相对表达量为0981±0225,高于NC组的0587±0254,以上差异均有统计学意义（P＜005）。 结论siRNA靶向沉默MIF能够降低SGC 7901细胞中MIF蛋白表达,抑制SGC 7901细胞的增殖并促进凋亡,在胃癌的靶向治疗中有一定前景。     

小干扰RNA在胃肠道肿瘤中的研究进展

 小干扰RNA（siRNA）是由双链RNA（dsRNA）经Dicer酶加工成的小分子片段。21～25 nt的siRNA作为RNA干扰（RNAi）过程中的关键效应分子,在哺乳动物细胞中能够高特异性、高效性地抑制基因的表达。目前,RNAi被广泛地应用于各种肿瘤的研究,在胃肠道肿瘤方面,针对肿瘤的发生发展、转移以及治疗等方面都有许多积极的研究探索。     

沉默Livin基因表达对结肠癌LoVo细胞生物学特性的影响

目的:运用RNA干扰(RNA interference,RNAi)技术沉默结肠癌细胞株LoVo中Livin基因的表达,研究Livin对LoVo细胞增殖和凋亡等生物学特性的影响.方法:构建针对Livin基因的干扰质粒pSilencer4.1-L1和pSilencer4.1-L2,转染LoVo细胞,通过RT-PCR、Wes...     

Adenoviral‐mediated RNA interference targeting URG11 inhibits growth of human hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the second most common malignancy in Asia, with a 5‐year survival rate of less than 5% due to high recurrence after surgery and resistance to chemotherapy. A variety of therapeutic interventions to treat HCC, particularly gene therapy, have recently been investigated in tumor model systems to provide a more complete understanding of hepatocarcinogenesis and effectively design therapeutic strategies to treat this disease. In our study, we constructed an adenoviral vector expressing small interfering RNA (siRNA) targeting a newly discovered gene named upregulated gene 11 (URG11). We introduced this vector into HCC cells to investigate the role of URG11 in HCC carcinogenesis. We observed that upon URG11 knockdown, HCC cell proliferation was inhibited through downregulation of several G1‐S phase related molecules including cyclin D1 and apoptosis was induced as a result of Bcl‐2 downregulation. Besides decreased expression of cyclin D1, CDK4, pRb and Bcl‐2, URG11 also suppressed several other proteins including CAPN9, which was identified by cDNA microarray and 2D gel electrophoresis. Moreover, Ad‐URG11‐siRNA significantly suppressed HCC tumor growth in nude mice. In conclusion, Ad‐URG11‐siRNA can significantly suppress HCC tumor growth in vitro and in vivo by silencing the URG11 gene, and the use of this vector for gene therapy may represent a novel strategy to treat human HCC.     

Short hairpin RNA-mediated MDR1 gene silencing increases apoptosis of human ovarian cancer cell line A2780/taxol

Objective: Recurrent ovarian cancer is often resistant to drugs such as paclitaxel. Short hairpin RNA (shRNA) targeting MDR1, a gene involved in the process of drug resistance, may be a promising strategy to overcome drug resistance. Methods: Construction and identification of eukaryotic expression plasmid of shRNA targeting on MDR1 gene. The plasmid was transiently transfected into human ovarian cancer cell line A2780/Taxol. Apoptosis was determined by flow cytometry using annexin V-FITC/PI double labeling. Expression of MDR1 mRNA was detected by quantitative polymerase chain reaction (qPCR) and P-glycoprotein expression was detected using Western blot. Results: The IC50 of paclitaxel in MDR1 shRNA-transfected group was significantly reduced (1.986±0.153) μmol/ml as compared with that in negative control (5.246±0.107) μmol/ml and empty vector-transfected group (5.212±0.075) μmol/ml (P<0.05). The percent of the relative reverse sensitivity to paclitaxel on A2780/Taxol cells was 67.1%, and the apoptotic rate was significantly increased [(6.977±0.333)%] compared with control [(1.637±0.111)%] and empty vector-transfected group [(1.663±0.114)%] (P<0.05). Expressions of MDR1 mRNA and P-glycoprotein were significantly reduced compared with control (P<0.05). Conclusion: The present study demonstrated that the eukaryotic expression plasmid of shRNA targeting on MDR1 inhibited the expression of MDR1 effectively, thus enhance the sensitivity of A2780/Taxol cells to paclitaxel.