Notch 3沉默对人急性T淋巴细胞白血病细胞增殖与凋亡的影响

目的：探讨Notch 3受体特异性沉默对急性T淋巴细胞白血病的影响。方法：运用survivin启动子介导的RNA干涉方法特异性地封闭急性T淋巴细胞白血病细胞SupT1中Notch 3基因的表达。结果：survivin启动子介导的RNA干涉系统能特异而高效封闭肿瘤细胞内源Notch 3基因的表达,Notch 3基因表达的下调能够使肿瘤细胞的增殖活性降低,凋亡明显增加。结论：Notch 3基因沉默可有效抑制白血病细胞的增殖,并促进其凋亡,为急性T淋巴细胞白血病相关基因功能研究及靶向性治疗探索了一种新策略。     

RNAi技术沉默survivin基因诱导MCF-7细胞凋亡的研究

目的:探讨RNA干扰技术沉默survivin基因表达对人乳腺癌细胞增殖和凋亡的影响.方法:设计并合成靶向survivin的小分子干扰RNA(siRNA),在脂质体(lipidosome)的介导下转染人乳腺癌细胞株MCF-7,荧光倒置显微镜观察细胞的转染效率; MTT(四甲基偶氮唑盐)比色法分析检测各组癌细胞的存活率;流式细胞计数检测各组癌细胞周期和凋亡指数;Western Blot方法观察对MCF-7细胞survivin mRNA和蛋白质表达的抑制效率.结果:Survivin-siRNA能有效封闭survivin基因的表达,使survivin的mRNA相对水平明显降低(P＜0.05);Survivin-siRNA能明显抑制细胞增殖(P＜0.05);Survivin-siRNA使细胞G2/M期细胞百分比明显增加,S期的细胞百分比显著减少(P＜0.05).结论:利用RNA干扰技术沉默survivin基因的表达可以显著抑制MCF-7细胞的增殖,并在一定程度上诱导其自发凋亡,靶向survivin的RNA干扰技术在乳腺癌的基因治疗中具有一定的研究价值.     

RNA干扰survivin对口腔表皮样癌细胞株 KB生长的抑制作用

 摘要：目的探讨RNA干扰技术沉默survivin基因对口腔表皮样癌细胞株KB增殖和凋亡的影响。方法化学合 成靶向survivin基因的小干扰RNA片段（siRNA）,脂质体法转染KB细胞。通过RT-PCR、蛋白印迹法分别检 测survivin mRNA和蛋白表达变化,流式细胞仪检测细胞生长周期和凋亡,MTT法检测转染后KB细胞增殖情 况。结果siRNA可以有效地降低KB细胞survivin mRNA和蛋白的表达;转染后KB细胞阻滞于G2/M期,凋亡增 加,增殖受抑制。结论应用RNA干扰技术沉默survivin 在KB细胞中的表达可以有效抑制该细胞增殖、促进 癌细胞凋亡,将survivin作为口腔癌基因治疗的靶点,通过RNA干扰技术对口腔癌进行基因治疗具有一定 的可行性。     

肿瘤特异性Survivin、Livin共沉默RNAi载体的构建及其在前列腺癌细胞中的RNA干涉作用

目的:构建含Survivin基因启动子的、肿瘤特异性Survivin、Livin共沉默RNAi载体,研究该载体在前列腺癌细胞中的RNA沉默作用。方法:运用分子克隆技术,选取Survivin、Livin基因RNAi特异性序列,构建以Survivin、Livin基因为靶点的、含Survivin启动子的CGM30 miR-30 shRNA载体。经测序验证,用脂质体法转染PC-3细胞,RT-PCR、免疫印迹实验检测Survivin、Livin的表达变化,并用流式细胞术检测转染后PC-3细胞的凋亡变化。结果:构建的共沉默RNAi重组载体转染PC-3细胞后,Survivin、Livin基因在mRNA和蛋白水平上的表达均明显下调（P＜0.01）,且转染后的细胞凋亡增加了约15％,而正常前列腺上皮BPH-1细胞中则无此作用。结论:成功构建了含Survivin启动子、特异性沉默Survivin、Livin基因表达的RNAi共沉默载体CGM30-SP-svv-liv,转染该重组质粒后可促进肿瘤细胞的凋亡。     

Notch1基因表达对急性T淋巴细胞白血病SupT1细胞增殖、凋亡的影响及其机制

目的探讨Notch信号通路与急性T淋巴细胞白血病发生、发展的关系。方法利用携带Notch1特异性和非特异性shRNA的慢病毒载体包装成的病毒颗粒感染急性T淋巴细胞白血病SupT1细胞,采用CCK．8法检测细胞抑制率;采用流式细胞术检测细胞凋亡率（AnnexinV＋／7-AAD一和AnnexinV＋／7-AAD＋）;采用实时荧光定量PCR法检测Notch1受体基因及下游靶基因的表达水平。结果Notch1干扰组、空白对照组和空载体组96h的细胞增殖抑制率分别为0．902±0．013、0、0．486±0．084,干扰组较空白对照组、空载体组升高（均P〈0．05）;三组细胞早期凋亡率分别为（15．27±0．31）％、（5．57±0．25）％、（5．80±0．20）％,干扰组较空白对照组、空载体组升高（均P〈0．05）;而各组细胞晚期凋亡率无明显变化（均P〉0．05）。干扰组细胞中Notch1受体基因及其下游靶基因Hes1、c-myc、NF-κB在48、72、96h的mRNA相对表达量均较空白对照组及空载体组降低（均P〈0．05）。结论特异性Notch1-shRNA可有效下调Notch1mRNA的表达,并降低其下游靶基因的表达水平。Notch1表达下调可以抑制急性T淋巴细胞白血病SupT1细胞增殖,促进supT1细胞的早期凋亡。     

Survivin反义寡核苷酸对骨肉瘤细胞凋亡的影响

目的:采用survivin反义寡核苷酸(ASODN)封闭骨肉瘤细胞survivin的作用,观察其对骨肉瘤细胞系MG63增殖和凋亡的影响。方法:以脂质体为载体,介导survivin反义寡核苷酸转染人骨肉瘤细胞系MG63,用MTT法测定细胞增殖;流式细胞仪检测转染survivin反义寡核苷酸后细胞凋亡率;Westernblot及半定量RTPCR检测转染survivin反义寡核苷酸后的骨肉瘤细胞survivin蛋白及mRNA表达。结果:脂质体介导survivin反义寡核苷酸转染骨肉瘤细胞系MG63后,细胞增殖明显受到抑制,细胞凋亡率明显增加,骨肉瘤细胞survivin蛋白及mRNA表达均明显降低。结论:脂质体介导转染survivin反义寡核苷酸可以抑制细胞增殖,有效降低细胞内survivin基因的表达,促进细胞凋亡。     

hTERT启动子靶向性驱动Bax诱导腺样囊性癌细胞凋亡机制的探讨

目的:探讨人端粒酶逆转录酶(hTERT)启动子调控Bax基因在端粒酶阳性的腺样囊性癌细胞-SACC-83中表达的特异性,以及Bax对SACC-83细胞增殖的影响.方法:脂质体介导pACTERT-Bax质粒载体转染SACC-83和端粒酶阴性的人胚肺成纤维细胞(HEL),通过RT-PCR检测Bax表达,MTT法检测Bax基因表达对细胞增殖的影响,流式细胞仪检测细胞凋亡率.结果:hTERT启动子调控Bax基因在SACC-83细胞中明显表达,对该肿瘤细胞的增殖有明显的抑制作用(相对活性58.90%),且诱导细胞凋亡比例增加(11.62%);而在HEL细胞中hTERT启动子未能诱导Bax基因表达,对该细胞的增殖和凋亡无明显影响.结论:hTERT启动子可以诱导Bax基因在SACC-83中特异性表达及诱导细胞凋亡,同时还能消除Bax基因对正常细胞的潜在毒性.     

Survivin-siRNA抑制肺癌A549细胞的增殖并增强其对顺铂的敏感性

目的：构建靶向存活素（survivin）的干扰RNA（siRNA）质粒,观察其对A549细胞增殖、凋亡以及顺铂敏感性的影响。方法：应用pSilencerU6质粒构建survivinsiRNA干扰质粒,RTPCR和Western blotting检测survivin mRNA和蛋白的表达,DAPI染色法检测细胞的凋亡,MTT法检测细胞的增殖。结果：成功构建了survivinsiRNA干扰质粒。SurvivinsiRNA质粒转染可明显下调A549细胞中survivin mRNA和蛋白的表达、抑制A549细胞的增殖、促进细胞的凋亡、增强A549细胞对顺铂的敏感性。结论：SurvivinsiRNA沉默survivin在肺癌细胞中的表达能够抑制肿瘤细胞的增殖、促进细胞凋亡,并能增强肿瘤细胞对化疗药物顺铂的敏感性,survivin 可作为肺癌治疗的潜在靶点。     

存活蛋白在子宫内膜癌中的表达及其在细胞凋亡中的作用

目的:探讨子宫内膜癌中存活蛋白(survivin)的表达及其对细胞凋亡的作用.方法:免疫组织化学法检测survivin在子宫内膜癌组织中的表达,并且应用RNA干扰技术沉默survivin基因,RT-PCR和Western印迹法检测RNA干扰效果,FCM法检测RNA干扰前后细胞凋亡的变化,Western印迹法检测凋亡相关蛋白caspase-3、caspase-8和bcl-2的表达变化.结果:子宫内膜癌组织中survivin蛋白的阳性率显著高于不典型增生和正常内膜组织(P<0.05和P<0.01).RNA干扰有效抑制了survivin mRNA和蛋白的表达(均为P<0.01),并且诱导了细胞凋亡,2个干扰组的细胞凋亡率均显著高于对照组(P<0.01).RNA干扰亦上调了活性caspase-3、caspase-8的表达.结论:survivin基因的异常表达与子宫内膜癌的发生密切相关,抑制其表达可以诱导子宫内膜癌细胞发生凋亡.     

瘦素诱导乳腺癌细胞的凋亡抵抗及其分子机制

目的 观察瘦素对乳腺癌细胞凋亡的影响,并探讨其分子机制.方法 采用TransAM酶联免疫吸附法(ELISA)检测瘦素对乳腺癌细胞T47D凋亡的影响,采用四甲基偶氮唑蓝(MTT)法检测细胞毒性,并测定T47D细胞caspase-9的活性.采用实时荧光定量逆转录聚合酶链反应(RT-PCR)和Western blot法测定瘦素对T47D细胞survivin mBNA和蛋白表达水平的影响.采用BNA干扰技术沉默信号转导和转录激活因子3(STAT3)基因,并采用实时荧光定量逆转录聚合酶链反应(RT-PCR)和Westem blot法测定瘦素对沉默STAT3基因后T47D细胞survivin mRNA和蛋白表达水平的影响.结果 瘦素可以促进人乳腺癌细胞T47D的增殖,增殖抑制率为63.6%;减少多西他赛诱导的细胞凋亡,达31.9%.不同浓度瘦素均可促进T47D细胞survivin mRNA的表达,其中以10 nmol/L时作用最明显.10 nmol/L瘦素作用60 min后,T47D细胞中survivin mRNA的表达量是瘦素作用前的4.6倍;作用2 h后,T47D细胞中survivin蛋白的表达增强.将STAT3小干扰RNA(siRNA)转入T47D细胞30 min后,survivin mRNA表达的变化倍率为0.55±0.15.经瘦素处理后,STAT3 siRNA质粒转染组和空质粒对照组survivin mRNA表达的变化倍率分别为0.56±0.18和1.61±0.22.将STAT3 siRNA转入T47D细胞后,survivin蛋白表达下降.经瘦素处理后,转染空质粒的细胞survivin蛋白的表达增加,而转入STAT3 siRNA的细胞survivin蛋白无明显变化.结论 在乳腺癌T47D细胞中,瘦素/STAT3信号通路是上调survivin表达的有效途径.     

Silencing of Notch3 Using shRNA driven by survivin promoter inhibits growth and promotes apoptosis of human T-cell acute lymphoblastic leukemia cells

BackgroundAs a highly conserved system, the activation of the Notch pathway has been implicated in the tumorigenesis of various hematologic diseases, including leukemias, lymphomas, and multiple myeloma. The Notch3 receptor is frequently expressed in T-cell acute lymphoblastic leukemia (T-ALL).MethodsTo explore its possibility as a therapeutic target for T-ALL, we investigated the effect of Notch3 silencing on Jurkat and SupT1 cells using a novel tumor-specific short hairpin RNA (shRNA) driven by survivin promoters.ResultsWe found that downregulated expression of Notch3 correlated with significant apoptosis and inhibition of proliferation.ConclusionThese facts suggest that downregulating expression of Notch3 could attenuate the Notch signaling activity in T-ALL. All these results indicate that inhibition of Notch3 expression can result in potent antitumor activity in T-ALL.     

RNA干扰技术抑制smad4基因表达对宫颈癌细胞增殖的影响

目的：探讨用RNA干扰技术下调smad4基因表达对宫颈癌细胞增殖的影响。方法：用DNA重组技术将针对人smad4基因不同部位所设计的三对短发夹状RNA（shorthairpinRNA，shRNA）序列克隆到真核表达质粒pGenesil-1中，构建smad4shRNA表达载体pGenesil—smad4一shRNA1、2、3。脂质体介导转染人宫颈癌细胞株HeLa，经G418筛选抑制smad4表达的稳定细胞克隆。MTT法、克隆形成实验、流式细胞术检测抑制smad4基因对宫颈癌细胞增殖的影响。结果：成功构建分别携带三段shRNA及空载体对照的重组质粒pGenesil—smad4-shRNA1、2、3和pGenesil-con，三种shRNA重组质粒中pGenesil—smad4-shRNA2可明显降低细胞内smad4mRNA及smad4蛋白表达，筛选出的HeLa／shRNA2细胞增殖能力明显增强。结论：应用RNA干扰技术能筛选出特异而高效阻断smad4基因表达及功能的shRNA，smad4基因表达下调能明显促进宫颈癌细胞生长。     

Notch1 signaling regulates the epithelial–mesenchymal transition and invasion of breast cancer in a Slug-dependent manner

Background

The epithelial–mesenchymal transition (EMT) is crucial for the invasion and metastasis of breast cancer. However, how Notch signaling regulates the EMT process and invasion in breast cancer remains largely unknown.

Methods

The impact of Notch1 silencing by specific shRNAs on the EMT and invasion of human breast cancer MCF-7 and MDA-MB-231 cells as well as xenografts was tested by western blot, real-time polymerase chain reaction (RT-PCR), immunofluorescence, transwell, and immunohistochemistry assays. The effect of Slug silencing or upregulation on the EMT and invasion of breast cancer cells was analyzed, and the effect of Notch1 signaling on Slug expression was determined by the luciferase reporter assay.

Results

The Notch1 intracellular domain (N1ICD) and Jagged1 were expressed in breast cancer cells. Notch1 silencing reversed the spontaneous EMT process and inhibited the migration and invasion of breast cancer cells and the growth of xenograft breast cancers. The expression of N1ICD was upregulated significantly by Jagged1-mediated Notch signaling activation. Moreover, Jagged1-mediated Notch signaling promoted the EMT process, migration, and invasion of breast cancer cells, which were abrogated by Notch silencing. Furthermore, the N1ICD positively regulated the Slug expression by inducing Slug promoter activation. Importantly, the knockdown of Slug weakened the invasion ability of breast cancer cells and reversed the Jagged1-induced EMT process with significantly decreased expression of vimentin and increased expression of E-cadherin. In addition, Slug overexpression restored the Notch1 knockdown-suppressed EMT process.

Conclusions

Our novel data indicate that Notch signaling positively regulates the EMT, invasion, and growth of breast cancer cells by inducing Slug expression. The Notch1–Slug signaling axis may represent a potential therapeutic target for breast cancer therapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-015-0295-3) contains supplementary material, which is available to authorized users.     

应用可调控Notch1干扰载体诱导HeLa细胞增殖抑制

背景与目的:Notch信号转导途径与细胞增殖与分化的调控密切相关,它的功能失调在肿瘤细胞的增殖分化中发挥着重要的作用.本研究构建了针对Notch1的可调控RNA干扰载体,并从分子水平及细胞水平上研究其对HeLa细胞的影响.方法:利用受CRE重组调控的RNA干扰载体pSico和pSicoR构建针对GAPDH和Notch1的shRNA表达载体,以pBS185-CRE作为CRE蛋白的表达载体,将HeLa细胞分为pSico、pSico/CRE、pSicoR和pSicoR/CRE 4组,分别转染相应质粒,RT-PCR和Western blot法检测干扰效率,CBF-1荧光素酶报告载体检测细胞内活性Notch信号水平,MTS实验检测细胞增殖状态.结果:各组细胞在转染重组质粒pSico(R)-GAPDH和pSico(R)-Notch1后,EGFP的表达均表现出明显的CRE依赖性;RT-PCR和Western blot实验显示,pSico(R)-Notch1载体能在CRE蛋白的调控下抑制Notch1基因的表达,CBF-1荧光素酶报告载体实验可见,Notch1的干扰作用使细胞内Notch信号水平下降;MTS实验可见Notch1干扰引起的HeLa细胞增殖抑制.结论:由可调控RNA干扰载体介导的CRE依赖性Notch1表达降低能降低细胞内Notch信号水平并抑制HeLa细胞增殖.     

Anti-tumor effects of the Notch pathway in gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are driven by gain-of-function mutations of KIT or PDGFRa. The introduction of imatinib has significantly extended survival for patients. However, most patients develop resistances. Notch signaling is a conserved developmental pathway known to play a critical role in the development of several cancers, functioning as a tumor promoter or a tumor suppressor. Given that the normal progenitor cell for GIST, the interstitial cell of Cajal, has characteristics similar to those of cells of neuroendocrine origin, we hypothesized that Notch pathway impacts the biology of GIST cells. In this study, we retrovirally and pharmacologically manipulated the Notch pathway in human GIST cells. We also performed a retrospective analysis of a cohort on 15 primary tumors to determine the role of Hes1, a major target gene of Notch, as a prognostic marker for GIST. Constitutively, active intracellular domain of Notch1 (ICN1) expression potently induced growth arrest and downregulated KIT expression in vitro. Additionally, treatment with the histone deacetylase inhibitor suberoylanilide hydroxamic acid caused dose-dependent upregulation of Notch1 expression and a parallel decrease in viability in these cells. Retroviral silencing of downstream targets of Notch (dominant-negative Hes1) and pharmacological inhibition of Notch activation (γ-secretase inhibition) partially rescued GIST cells from suberoylanilide hydroxamic acid treatment. GIST patients with high Hes1 mRNA levels have a significantly longer relapse-free survival. These results identify a novel anti-tumor effect of Notch1 and cross talk between the Notch and KIT pathways. Thus, activation of this pathway by treatment with histone deacetylase inhibitors is an appealing potential therapeutic strategy for GISTs. Précis: This study is the first report of the tumor suppressor effects of Notch pathway in gastrointestinal stromal tumors via a negative feedback with the oncogene KIT and may lead the development of new therapeutic strategies for GISTs patients.     

Adenovirus-mediated Aurora A shRNA driven by stathmin promoter suppressed tumor growth and enhanced paclitaxel chemotherapy sensitivity in human breast carcinoma cells

Aurora A has multiple key functions in tumor initiation and progression and is overexpressed in many cancers. Several ongoing clinical trials are assessing the unique therapeutic potential of Aurora-based targeted therapy, but several severe adverse events such as hematopoietic toxicity have been observed in the early-phase clinical trials because Aurora A is also involved in normal cells proliferation process. The strategy to develop tumor-specific inhibition of this target may be an alteration for the treatment of Aurora A overexpression tumors. In this study, we developed a novel tumor-specific RNA interference adenovirus system targeting Aurora A by using stathmin promoter and investigated the effects of it on the proliferation, apoptosis and chemotherapy sensitivity in human breast carcinoma cells both in vitro and in vivo. The results showed that treatment of human breast carcinoma cells (SK-BR-3 and MDA-MB-231) by Aurora A short hairpin RNA (shRNA) driven by stathmin gene promoter not only inhibited the cells proliferation, but also enhanced the chemosensitivity to paclitaxel via downregulation of Aurora A mRNA and protein expression, which further decreased the phosphatidylinositol 3 kinase/Akt and p-BRCA1 protein expression. Furthermore, there were no obvious phenotypes changes observed in normally differentiated epithelial cells of MCF210. Therefore, stathmin promoter-driving Aurora A shRNA adenoviral system may have potential use, with targeted tumor gene silencing effect and as adjuvant tumor-specific therapy method, in the treatment of human breast carcinomas.