RNA干扰Slug基因对HCT116细胞裸鼠移植瘤生长及转移的影响

目的：探讨通过靶向RNA干扰（RNA interference,RNAi）抑制Slug基因的表达,观测对荷瘤裸鼠结直肠癌生长及转移的影响。方法：利用结肠癌细胞株HCT116对24只5周龄裸鼠皮下种植,建立结肠癌裸鼠皮下移植瘤模型,设立空白对照组、阴性对照组及实验组三组,每组8只。分别注射生理盐水、阴性对照质粒及慢病毒载体,观察肿瘤生长情况,绘制肿瘤生长曲线,观察各组间肿瘤生长及淋巴结转移的变化,应用免疫组化、qRT-PCR和Western blot检测Slug基因和蛋白表达情况。结果：Slug基因shRNA实验组与空白对照组和阴性对照组相比,瘤体生长减缓,移植瘤质量明显减小（3.08±0.31 vs 7.37±1.18,7.46±1.16,P＜0.01）,Slug蛋白表达明显降低（P＜0.05）;实验组淋巴结阳性率为36.3％（4/11）,与阴性对照组77.8％（14/18）及空白对照组68.4％（13/19）相比较（P＜0.01）。结论：靶向Slug的RNA干扰可以显著抑制结肠癌裸鼠模型的生长、淋巴结转移以及癌组织中Slug基因蛋白的表达,可能成为结肠癌基因治疗的潜在分子靶点。     

Slug基因RNAi慢病毒载体的构建与鉴定

目的构建Slug基因RNA干扰(RNA interference,RNAi)慢病毒表达载体。方法针对人Slug基因的序列,设计出RNA干扰的靶序列,合成靶序列Oligo DNA,退火形成双链DNA,通过Age I和EcoR I酶切后的pGCSIL-GFP载体连接产生shRNA慢病毒载体,质粒转化感受态细菌,筛选阳性克隆并用插入鉴定引物进行PCR鉴定阳性克隆并测序,同时应用Real-time PCR和Western blot方法检测HCT116结肠癌细胞中Slug基因mRNA和蛋白的表达情况。结果 PCR鉴定与DNA测序证实合成的含Slug shRNA慢病毒载体寡核苷酸链插入正确。Western blot证实Slug RNAi慢病毒载体能够抑制Slug的表达。结论成功构建Slug基因RNAi慢病毒表达载体,为后续感染结肠癌细胞,为探索在结直肠癌发生和发展中的作用奠定基础。     

RNA干扰沉默增殖诱导配体基因对结肠癌细胞周期的影响

目的 探讨沉默增殖诱导配体(a proliferation-inducing ligand,APRIL)基因对人结肠癌SW480细胞增殖及细胞周期的影响.方法 将APRIL基因的小干扰RNA质粒载体(siRNA-APRIL)转染结肠癌SW480细胞株,以非特异性序列载体转染组(nontargeting control)及未转染组(nontransfected control)作为对照.Real-time PCR和Western blot评价APRIL沉默效率;CCK-8(cell counting kit-8)法检测细胞增殖情况;流式细胞术检测细胞周期变化;RT-PCR检测细胞周期调控基因p21及p27的表达.结果 与非特异性序列载体转染组及未转染组相比,siRNA-APRIL显著抑制APRIL mRNA及蛋白的表达(P＜0.05);siRNA-APRIL转染SW480细胞48 h、72 h和96 h后细胞增殖能力明显下降(P＜0.05);转染48 h,siRNA-APRIL组G0/G1期细胞比例增高,S期及G2/M期细胞比例减少,细胞凋亡的数量增加,同时p21及p27 mRNA的表达上调(P＜0.05);而上述指标两对照组之间比较差异无统计学意义(P＞0.05).结论 siRNA-APRIL能特异性抑制结肠癌SW480细胞APRIL的表达,并抑制细胞增殖,使细胞周期出现G0/G1期阻滞,其机制可能与上调p21和p27的表达有关.     

RNA干扰MAD2基因对细胞增殖的影响

目的:探讨MAD2对HepG2细胞周期的影响。方法:构建针对MAD2基因的shRNA表达载体,MAD2基因与GFP融合的绿色荧光蛋白真核表达质粒pmad2-EGFP共转染HepG2细胞株,用Western印迹法检测shRNA的抑制效应;用MTT法测定细胞增殖率;用流式细胞仪检测细胞周期。结果:shRNA的重组质粒表达载体能明显抑制MAD2绿色荧光融合蛋白的表达。HepG2细胞转染有效干扰质粒48h后,细胞增殖抑制率达65%。有效干扰质粒引起G0/G1期和S期细胞的明显降低,G2/M期细胞增多。结论:在细胞水平,可通过RNA干扰特异性抑制MAD2基因来抑制细胞的增殖,为研究MAD2基因在细胞增殖中的作用机制奠定基础。     

RNA干扰EP—CAM基因表达对胆囊癌细胞增殖及凋亡的影响

目的：利用RNA干扰技术抑制人胆囊癌GBC-SD细胞中上皮细胞黏附分子（EP-CAM）基因的表达,探讨抑制EP-CAM基因后对GBC-SD细胞增殖、凋亡的影响.方法：构建靶向EP-CAM基因的miRNA重组质粒,转染GBC-SD细胞,用RT-PCR和Western Blot分别检测EP-CAM基因的mRNA及蛋白的表达情况,MTT法检测细胞增殖活性,流式细胞仪检测细胞凋亡的变化.结果：靶向EP-CAM的miRNA重组质粒pcDNA^TM6.2-GW/EmGFPmiR-EPCAM-1构建成功,重组质粒能显著抑制靶基因EP-CAM的mRNA及蛋白表达.与对照组比较,干扰后的细胞凋亡率无明显变化（P＞0.05）,但细胞增殖活性受到明显抑制（P＜0.05）.结论：靶向EP-CAM基因的miRNA重组质粒能有效抑制EP-CAM基因的表达,抑制GBC-SD细胞的增殖.     

E盒锌指结合蛋白1基因沉默抑制结肠癌HCT116细胞增殖并促进其凋亡

目的使用针对E盒锌指结合蛋白1(ZEB1)的siRNA在结肠癌HCT116细胞中下调ZEB1的表达,研究其对HCT116细胞增殖和凋亡的影响。方法根据人ZEB1的mRNA序列设计并合成2对针对ZEB1的siRNA,瞬时转染HCT116细胞后,利用实时荧光定量PCR,Western blot法分别在mRNA和蛋白水平检测siRNA对ZEB1的抑制效果;利用MTT法检测细胞增殖;AnnexinⅤ-FITC/PI染色结合流式细胞术检测细胞凋亡情况。结果与对照组相比,针对ZEB1的siRNA可在mRNA和蛋白水平有效抑制ZEB1的表达,ZEB1的表达下调可有效抑制HCT116细胞的增殖,并促进细胞凋亡。结论 ZEB1对结肠癌细胞的生存和增殖具有重要作用,可能参与结肠癌的发生发展过程。     

小干扰RNA沉默hPTTG1基因对卵巢癌细胞增殖和凋亡的影响

目的: 利用RNA干扰技术沉默人垂体瘤转化基因1( hPTTG1 )表达,观察卵巢癌细胞增殖能力和细胞凋亡的改变并探讨分子机制。方法: 化学合成靶定 hPTTG1 的小干扰RNA(siRNA)转染体外培养的A2780细胞,RT-PCR和Western blotting检测 hPTTG1 及c-myc表达水平;MTT法和 -TdR掺入实验检测 hPTTG1 对细胞增殖的影响;annexin V/PI染色流式细胞术和TUNEL法测定各组细胞凋亡情况。结果: hPTTG1 siRNA转染组 hPTTG1 mRNA和蛋白表达下降,抑制率分别为70.5%±3.9%和63.8%±4.5%;转染 hPTTG1 siRNA 24 h细胞吸光度值开始下降,48 h抑制效果最明显,抑制率为42.9%±5.2%;转染 hPTTG1 siRNA后细胞 -TdR放射性计数明显低于空白组和阴性对照组; hPTTG1 siRNA干扰组细胞存活率下降,细胞凋亡率和坏死率均增加;TUNEL染色分析结果可见 hPTTG1 siRNA干扰组凋亡指数明显高于空白组和阴性对照组; hPTTG1 干扰后c-myc mRNA和蛋白表达均下调。结论: hPTTG1 siRNA通过下调c-myc表达抑制A2780细胞增殖,诱导细胞凋亡, hPTTG1 可作为卵巢癌基因治疗的候选靶点。     

RNA干扰Notch1基因对乳腺癌MCF-7细胞增殖及凋亡的影响

目的探讨RNA干扰技术沉默Notch1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Notch1基因的小分子干扰RNA质粒,在转染试剂Sofast介导下转染人乳腺癌细胞株MCF-7,用RT-PCR和Western blot法检测转染前、后Notch1基因的表达,挑选干扰效率最强的一组表达载体;cck8比色法检测分析各组细胞的存活率;流式细胞术检测细胞凋亡比例;Western blot法检测转染各组MCF-7细胞Notch1、NF-κB及Caspase-3蛋白表达。结果 Notch1-shRNA能有效封闭Notch1基因的表达,Notch1基因和蛋白表达水平明显降低(P<0.05);Notch1-shRNA能明显抑制细胞增殖(P<0.05);转染48h后细胞凋亡比例增加(P<0.01)。NF-κB蛋白水平表达降低,Caspase-3蛋白表达水平增高。结论利用RNA干扰技术沉默Notch1基因的表达可以明显抑制MCF-7细胞的增殖,促进MCF-7细胞凋亡,其机制可能通过NF-κB信号通路调节相关凋亡蛋白的表达,进而影响细胞的凋亡和增殖,靶向Notch1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。     

干扰盐皮质激素受体基因对RAW 264.7细胞增殖和凋亡的影响

 目的：应用RNA干扰技术沉默小鼠RAW 264.7巨噬细胞盐皮质激素受体(MR)基因,建立稳定干扰细胞株,并观察其对细胞增殖和凋亡的影响。方法：针对MR基因设计合成重组MR shRNA质粒,脂质体法转染质粒至RAW 264.7细胞,经G418筛选后获得稳定表达细胞株。细胞分为3组：野生型(WT)组、阴性对照（NC）组和干扰（shMR）组。荧光显微镜下观察确定细胞的转染效率;实时定量PCR法检测细胞中MR mRNA的表达;CCK-8方法检测细胞增殖活性;流式细胞术分析细胞周期分布和凋亡情况。结果：(1) MR shRNA能明显抑制RAW 264.7细胞的MR基因表达,抑制率70%以上。(2) 从第3 d开始,shMR组细胞的生长速度明显低于NC和WT组（P<0.05）,说明MR shRNA能明显抑制细胞增殖。(3) WT、NC和shMR组的增殖指数分别为(37.2±0.5)%、(37.5±1.6)%和(31.0±1.3)%,shMR组的细胞周期出现改变,S期和G₂/M期比例明显下降,增殖指数下降（P<0.05）。(4) WT、NC和shMR组的细胞凋亡率分别为(2.18±0.36)%、(6.65±0.81)%和(7.70±1.34)%,shMR组略高于NC组,但二者的差异无统计学意义（P>0.05）。结论：本研究成功构建了稳定干扰MR基因表达的RAW 264.7细胞株,MR shRNA能够明显抑制RAW 264.7细胞增殖,但对其凋亡无明显影响。     

Knockdown of NPM1 by RNA interference inhibits cells proliferation and induces apoptosis in leukemic cell line

Nucleophosmin (NPM1) is an abundant and ubiquitously expressed phosphoprotein that is known to influence solid tumors progression. However, little is known about the role of NPM1 in leukemia. Here, we knocked down the NPM1 expression by RNA interference to investigate the role of NPM1 in leukemic cells proliferation and apoptosis. The interference vector pNPM1-shRNA was constructed and transfected into the human leukemic K562 cell line. The expression levels of NPM1 mRNA and protein were detected by quantitative real-time PCR and Western blot, respectively. Cells proliferation potential in vitro was assessed by methyl thiazolyl tetrazolium (MTT) and colony formation assays. Flow cytometry was used to detect the distribution of cell cycle. Cellular apoptosis was reflected by the relative activities of caspase-3 and caspase-8. The results showed that the expression levels of NPM1 mRNA and protein in K562 cells were significantly reduced after pNPM1-shRNA transfection. The cells growth was significantly inhibited in a time-dependent manner and the number of colonies was significantly reduced in the pNPM1-shRNA transfected cells. Meanwhile, the percentage of cells in G1 phase in the K562/pNPM1-shRNA cells was significantly increased. In addition, there were higher relative activities of caspase-3/8 in the pNPM1-shRNA transfected cells. These results indicate that down-regulation of NPM1 expression inhibits leukemic cells proliferation, blocks cell cycle progression and induces cellular apoptosis. It may implicate a potential target for leukemia gene therapy.     

miR-375对人结肠癌细胞株HCT116活性、细胞周期及凋亡的影响

目的:探讨微小RNA-375(microRNA-375,miR-375)对人结肠癌细胞HCT116活性、细胞周期及凋亡的影响。方法:Real-time PCR检测不同结直肠癌细胞中miR-375的表达情况。脂质体转染法将miR-375模拟物(mimics)转入HCT116细胞,用real-time PCR法检测miR-375及AEG-1 mRNA的表达情况;MTT法检测细胞活性的改变情况;流式细胞技术检测miR-375对细胞凋亡及细胞周期的影响。结果:Real-time PCR结果显示HCT116在4个结直肠癌细胞株中miR-375的表达量最低;miR-375 mimics组中miR-375表达量较对照组明显上调;miR-375高表达可以显著抑制AEG-1 mRNA的表达水平。miR-375 mimics组细胞活性明显受到抑制,同时细胞凋亡率明显增加,G1期所占细胞数增加,而S期所占细胞数减少。结论:miR-375可以抑制结肠癌HCT116细胞的活性,介导细胞周期阻滞并促进其凋亡。miR-375作为一种抑癌因子,在结肠癌中可能通过抑制AEG-1发挥抑癌作用。     

RNA干扰抑制乙酰肝素酶对肺腺癌细胞A549增殖、侵袭和凋亡的影响

目的 探讨抑制乙酰肝素酶表达对人肺腺癌细胞A549增殖、侵袭和凋亡的影响.方法 构建靶向人乙酰肝素酶基因短发夹状双链RNA(shRNA)真核表达质粒(pshRNA-Hpa),用脂质体将其转入A549细胞,建立稳定转染细胞株系,经逆转录.PCR和Western blot法检测转染效率后,分别用四甲基偶氮唑蓝(MTT)、Transwell侵袭实验和流式细胞术(AnnexinV-FITC/PI双染法)检测其对A549细胞增殖、侵袭和凋亡的影响.采用Western blot法检测转染后磷酸化蛋白激酶B(PKB/Akt-Ser473)的表达.结果 转染pshRNA-Hpa的A549细胞乙酰肝素酶mRNA及蛋白表达明显低于未处理A549细胞,抑制率分别为54.09%和48.26%,细胞增殖速度减缓,侵袭能力降低,流式细胞术显示早期细胞凋亡率达(12.53±0.34)%,较空白对照组、空载体转染细胞组和阴性对照组明显增加(P＜0.01).同阴性对照质粒相比,转染pshRNA-Hpa的A549细胞Akt-Ser473的磷酸化水平降低52.15%.结论 靶向乙酰肝素酶重组shRNA质粒pshRNA-Hpa能有效抑制A549细胞乙酰肝素酶的表达,并可能通过下调磷酸化蛋白激酶B途径抑制细胞的增殖侵袭、促进细胞的凋亡.     

下调p21活化蛋白激酶2表达对人乳腺癌细胞增殖和凋亡的影响*

 目的： 应用RNA干扰技术下调人乳腺癌MCF-7细胞中p21活化蛋白激酶2（PAK2）的表达,观察其对MCF-7细胞增殖和凋亡的影响。方法: 构建针对PAK2基因的短发卡RNA(shRNA)慢病毒表达载体并包装病毒颗粒,感染MCF-7细胞,筛选获得稳定细胞株。Western blotting检测细胞中PAK2蛋白表达水平的改变;CellTiter 96 AQueous法和软琼脂集落形成实验检测MCF-7细胞体外增殖能力的改变;流式细胞术检测十字孢碱诱导的MCF-7细胞凋亡的变化。结果: MCF-7细胞的PAK2基因被沉默后,PAK2蛋白表达量明显下降（P<0.01）,与阴性对照组相比,sh-PAK2组细胞生长明显减缓（P<0.01）,克隆形成的数目和大小明显下降（P<0.01）,十字孢碱诱导的细胞凋亡率显著增加（P<0.01）。结论：通过RNA干扰技术下调PAK2的表达,可抑制MCF-7细胞的生长和增殖,并增强其对化疗药物诱导的细胞凋亡的敏感性。PAK2可能是潜在的乳腺癌治疗的新靶点。     

靶向泛素连接酶SIAH2的shRNA对人肝癌细胞株HepG2细胞周期和凋亡的影响

 目的：探讨shRNA介导的泛素连接酶SIAH2(seven in absentia homolog 2)基因表达抑制对人肝癌细胞株HepG2细胞周期和凋亡的影响。方法：用已构建的pGenesil-SIAH2重组质粒转染HepG2细胞,荧光显微镜下观察转染效率。采用RT-PCR和Western blotting 技术检测重组质粒对SIAH2 mRNA和蛋白表达的影响,MTS比色法测定重组质粒转染对细胞体外增殖能力的影响,流式细胞术检测重组质粒转染后细胞周期和凋亡的变化。结果：与对照组相比,pGenesil-SIAH2能显著抑制SIAH2 mRNA和蛋白的表达水平;pGenesil-SIAH2转染组细胞增殖速度明显减慢;pGenesil-SIAH2组细胞明显阻滞于G1期,细胞凋亡率明显升高。结论: pGenesil-SIAH2能有效抑制HepG2增殖,使细胞周期阻滞在G1期,并诱导其早期凋亡。上述研究为以SIAH2为靶点的肝癌基因治疗提供实验依据。     

RNA interference targeting ORC1 gene suppresses the proliferation of vascular smooth muscle cells in rats

Background

The proliferation of vascular smooth muscle cells (VSMCs) plays an important role in the pathogenesis of vascular diseases such as atherosclerosis and postangioplasty restenosis. The largest subunit of the origin recognition complex (ORC), ORC1, plays a critical role during the initiation of DNA replication in eukaryotes. However, the involvement of ORC1 in the initiation of DNA replication in VSMCs has not been studied yet.

Objective

The aim of this study was to silence ORC1 gene selectively by using RNA interference and analyze the effects of ORC1 gene on the proliferation and apoptosis of rat VSMCs.

Methods

Freshly isolated rat VSMCs were transfected with siRNA targeting ORC1 gene capsulated in liposome. ORC1 protein expression was determined by Western blotting and ORC1 mRNA level by RT-PCR. DNA synthesis was analyzed by ³H thymidine (³H-TdR) incorporation and cell proliferative activity and cell cycle distribution by flow cytometry. Two apoptosis-related proteins, Bax and Bcl-2, were examined immunohistochemically.

Results

Down-regulation of ORC1 mRNA and protein expression was observed in rat VSMCs at 24 h after transfection with the three pairs of siRNA targeting ORC1 gene and this reduction persisted at least 7 days post-transfection. Down-regulation of ORC1 mRNA (60%) and protein (80%) expression was observed at 72 h post-transfection in the cells transfected with B-ORC1 siRNA. A significant decrease in ³H thymidine incorporation was observed in rat VSMCs with ORC1 gene silencing after serum challenge, but not in the non-silenced control. A significant increase in the proliferation index and a significant decrease in the percentage of cells at G₀/G₁ phase after serum challenge were observed in the non-silenced control, but not in ORC1 gene silenced cells. A significant increase in the ratio of Bcl-2/Bax was observed after serum challenge in the non-silenced control, but only a slight increase was found in the ORC1 gene silenced cells. ORC1 gene silencing disappeared 7 days after transfection. Continuous serum challenge stimulated VSMCs to synchronously reenter the cell cycle as evidenced by increases in [³H] thymidine incorporation, the proliferation index, and the ratio of Bcl-2/Bax, as non-silenced cells were induced to resume cell cycle progression by the addition of 15% fetal bovine serum to the culture medium.

Conclusion

ORC1 gene silencing causes rat VSMCs to enter a reversible G₀ quiescent, growth arrested state; thus, ORC1 gene may be an important new target for suppressing VSMCs proliferation.     

脑源性神经营养因子基因沉默对HeLa细胞增殖和凋亡的影响

目的 以高表达脑源性神经营养因子(BDNF)的官颈癌细胞系HeLa细胞为模型,筛选针对BDNF基因的有效干扰RNA序列,并观察BDNF基因沉默对HeLa细胞增殖和凋亡的影响.方法 设计和构建两个针对人BDNF基因的siRNA真核表达载体,经酶切鉴定和DNA序列分析鉴定后用脂质体Lipofectamine 2000介导转染,将空载体质粒pGenesil-1和两个重组质粒pGenesil-shRNA-BDNF1、pGenesil-shRNA-BDNF2分别转染人人HeLa细胞(依次命名为P_0、P_1和P_2组);采用RT-PCR和Western blot法分别从mRNA水平和蛋白水平检测BDNF表达的变化;四甲基偶氮唑盐(MTT)法检测细胞的增殖水平;流式细胞仪和Hoechest 33258染色检测细胞凋亡.结果 成功构建了针对BDNF的siRNA真核表达载体.P_1组与未转染、P_0、P_2组相比,BDNF mRNA表达水平(F=48.19,P<0.01)和BDNF蛋白表达水平(F=13.74,P<0.01)均明显降低,P_2组则未达实验预期的干扰目的 (P>0.05).通过MTT实验,发现P_1组细胞生长速度明显减慢,增殖高峰后移;流式细胞术检测证实早期凋亡率P_1组[(53.4±4.2)%]明显高于未转染组[(0.8±0.4)%]、P_0组[(5.1±1.8)%]和P_2组[(7.9±2.4)%;F=269.77,P<0.01].结论 BDNF基因高表达于官颈痛细胞系HeLa细胞,BDNF基因沉默能明显增加HeLa细胞的凋亡并抑制其增殖,提示BDNF基因可能成为恶性肿瘤治疗的新靶点.