胞内氯离子通道蛋白1基因沉默对小鼠肝癌细胞株增殖及侵袭能力的影响

目的 合成和筛选有效抑制细胞内氯离子通道蛋白1 (CLICl) 基因的shRNA序列,构建表达质粒,并进一步研究CLIC1基因的表达被抑制后小鼠肝癌细胞株Hca-F细胞增殖及侵袭能力的变化.方法 设计并合成3条理论上最佳的siRNA序列,进而将相应的双链DNA插入pGPU6/GFP/Neo质粒中,以脂质体Lipofectamine 2000将DNA质粒稳定转染至小鼠Hca-F细胞中,收取细胞进行逆转录多聚酶链反应分析各组的CLIC1 mRNA表达水平,选出最佳干扰序列.应用细胞计数试剂盒检测最佳干扰序列表达质粒稳定转染的Hca-F细胞,对比观察其干扰前后增殖情况的变化;应用transwell小室检测其侵袭能力的变化.对研究数据应用统计学软件SPSS13.0进行方差分析.结果 靶向CLIC1 mRNA的3个shRNA重组质粒载体经测序分析,shRNA编码序列与设计的片段完全一致.经酶切凝胶电泳证实载体构建成功.稳定转染pGPU6/GFP/Neo-shRNA-3表达质粒的Hca-F细胞对其CLIC 1 mRNA抑制效果明显,抑制率达42.4%.经该表达质粒的干扰后,Hca-F细胞的增殖能力明显增强,侵袭能力显著下降,空白对照组、无关序列处理组、shRNA干扰组的穿膜细胞个数分别为98.93±5.00、96.27±2.60、50.73±3.89,P值均<0.01.结论 pGPU6/GFP/Neo-shRNA-3表达质粒能高效地抑制小鼠Hca-F细胞中CLIC1 mRNA的表达,CLIC1基因具有抑制小鼠肝癌细胞的增殖和促进其侵袭的作用.     

H.pylori对胃癌细胞线粒体外膜蛋白VDAC1表达的影响

目的观察幽门螺杆菌(H.pylori)作用于胃癌细胞后线粒体外膜蛋白VDAC1 mRNA及蛋白的表达变化,探讨H.pylori通过线粒体途径致凋亡的分子机制。方法H.pylori分别作用于胃癌细胞0、12、24、48 h后,收集细胞,应用RT-PCR和Western blot法检测各时相点VDAC1 mRNA和蛋白表达变化。结果H.pylori与胃癌细胞共培养12 h后,VDAC1 mRNA及蛋白的表达增加,24 h增加更明显,48 h达到高峰。VDAC1 mRNA及蛋白各时相点的表达量明显高于对照组(P<0.05)。结论H.pylori可能通过上调胃癌细胞线粒体外膜蛋白VDAC1 mRNA及蛋白的表达,引起线粒体外膜通透性改变,导致凋亡发生。     

Gli-1 siRNA induced apoptosis in Huh7 cells

AIM： To investigate the effects of Gli-1 small interference RNA （siRNA） on Huh7 cells, and the change of Bcl-2 expression in Huh7 cells. METHODS： Human hepatocellular carcinoma cells Huh7 were used. Cell viability was analyzed by 3-（4, 5-Dimethylthiazol-2-yl）-2, 5-diphenyl tetrazolium bromide （MTT） assay. The expressions of Gli-1 and Bcl-2 family members were detected by RT-PCR and Western blot. Apoptosis was detected by Flow cytometry using propidium iodide, measured by Hoechst 33258 staining using Advanced Fluorescence Microscopy and caspase-3 enzymatic assay. Cell growth was analyzed after treatment with Gli-1 siRNA and 5-fluorouracil （5-Fu）. RESULTS： Inhibition of Gli-1 mRNA in Huh7 cells through Gli-1 siRNA reduced cell viability. Gli-1 siRNA treatment also induced apoptosis by three criteria, increase in the sub-G1 cell cycle fraction, nuclear condensation, a morphologic change typical of apoptosis, and activation of caspase-3. Gli-1 siRNA was also able to down-regulate Bcl-2. However, Gli-1 siRNA resulted in no significant changes in Bcl-xl, Bax, Bad, and Bid. Furthermore, Gli-1 siRNA increased the cytotoxic effect of 5-Fu on Huh7 cell. CONCLUSION： Down-regulation of Bcl-2 plays an important role in apoptosis induced by Gli-1 siRNA in HCC cells. Combination Gli-1 siRNA with chemotherapeutic drug could represent a more promising strategy against HCC. The effects of the strategies need further investigation in vivo and may have potential clinical application.     

Piwi like RNA-mediated gene silencing 1 gene as a possible major player in gastric cancer

AIM To establish a permanent piwi like RNA-mediated genesilencing 1(PIWIL1) gene knockout in AGP01 gastric cancer cell line using CRISPR-Cas9 system and analyze phenotypic modifications as well as gene expression alterations.METHODS CRISPR-Cas9 system used was purchased from Dharmacon GE Life Sciences(Lafayette, CO, United States) and permanent knockout was performed according to manufacturer's recommendations. Woundhealing assay was performed to investigate the effect of PIWIL1 knockout on migration capability of cells and Boyden chamber invasion assay was performed to investigate the effect on invasion capability. For the gene expression analysis, a one-color microarray-based gene expression analysis kit(Agilent Technologies, Santa Clara, CA, United States) was used according to the protocol provided by the manufacturer. RESULTS PIWIL1 gene knockout caused a significant decrease in AGP01 migration capacity as well as a significant decrease in cell invasiveness. Moreover, functional analysis based on grouping of all differentially expressed m RNAs identified a total of 35 genes(5 up-regulated and 30 down-regulated) encoding proteins involved in cellular invasion and migration. According to current literature, 9 of these 35 genes(DOCK2, ZNF503, PDE4 D, ABL1, ABL2, LPAR1, SMAD2, WASF3 and DACH1) are possibly related to the mechanisms used by PIWIL1 to promote carcinogenic effects related to migration and invasion, since their functions are consistent with the changes observed(being up-or down-regulated after knockout). CONCLUSION Taken together, these data reinforce the idea that PIWIL1 plays a crucial role in the signaling pathway of gastric cancer, regulating several genes involved in migration and invasion processes; therefore, its use as a therapeutic target may generate promising results in the treatment of gastric cancer.     

RNAi沉默Polo-like kinase-1基因表达对胰腺癌细胞增殖的影响

目的:探讨polo-like kinase-1(PLK1)基因在胰腺癌细胞中的作用.方法:采用PLK1小干扰核糖核酸分子(small interfering RNA,siRNA)转染人胰腺癌Mi- aPaCa-2细胞后,分别采用实时定量PCR和Western blot检测PLK1基因mRNA和蛋白表达水平,观察PLK1 siRNA转染对胰腺癌细胞体内外增殖的影响.于转染不同时间后收集细胞,分别采用琼脂糖凝胶电泳和TUNEL方法检测胰腺癌细胞凋亡情况.结果:胰腺癌MiaPaCa-2细胞经siRNA转染处理后,PLK1 mRNA和蛋白表达水平明显下降(P<0.05).PLK1基因siRNA可明显抑制癌细胞体外生长(P<0.05)和体内裸鼠模型增殖(P<0.05).细胞凋亡检测发现,DNA电泳出现明显的梯度图谱,且与浓度相关(r=0.836,P<0.05).TUNEL结果显示,转染组癌细胞凋亡指数明显增加,且呈时间和浓度依赖性(r= 0.875,P<0.05).结论:PLK1 siRNA转染可明显抑制胰腺癌细胞增殖,其机制可能与诱导细胞凋亡有关.     

Abl相互作用蛋白1过表达对胃癌细胞系AGS体外凋亡及迁移的影响

目的 研究Abl相互作用蛋白1(ABI1)过表达对人胃癌细胞系AGS体外凋亡及迁移的影响,初步探讨ABI1在胃癌发生发展中可能的作用机制.方法 首先应用脂质体转染方法分别将基因重组表达载体鼠干细胞病毒(MSCV)-绿色荧光蛋白(GFP)-ABI1质粒和对照载体MSCV-GFP质粒导入胃癌细胞系AGS,用嘌呤霉素筛选获得稳定表达MSCV-GFP-ABI1和MSCV-GFP的细胞系;其后应用流式细胞仪及Transwell小室检测ABI1过表达对AGS细胞体外凋亡及迁移能力的影响.结果 流式细胞仪检测显示,AGS细胞凋亡率与ABI1过表达后AGS细胞凋亡率无明显变化,差异无统计学意义(P＞0.05);Transwell小室检测显示,AGS细胞迁移能力与ABI1过表达后AGS细胞迁移能力比较差异有统计学意义(P＜0.01).结论 ABI1过表达抑制胃癌细胞系AGS的体外迁移能力,提示影响胃癌细胞的迁移可能是ABI1在胃癌发生发展中发挥作用的重要途径之一.     

反义端粒酶基因与顺铂诱导原代胃癌细胞凋亡作用的研究

目的　探讨端粒酶反义寡核苷酸 (PS- ASODN)与顺铂 (DDP)联合应用对原代胃癌细胞凋亡作用的影响。方法　常规组织块培养法进行胃癌细胞原代纯化培养 ,取第 3代对数生长期细胞分六组进行实验。其中四组在培养 2 4小时及 4 8小时分别加入相同剂量的培养液 ,终浓度为 PS- ASODN3μM,N- ASODN3μM,DDP2 .0μg/ ml。作用 2 4小时后分别在 PS- ASODN组及 N- ASODN组加入终浓度为 2 .0 μg/ ml的 DDP;分别于培养后 2 4、4 8、72及 96小时收集各组细胞。以台盼蓝拒染法计算各组细胞生长抑制率 ,观察 PS- ASODN联合 DDP对原代胃癌细胞生长的影响 ;流式细胞学观察细胞凋亡率及细胞周期变化。结果　终浓度为 3μM的 PS- ASODN作用于原代胃癌细胞 2 4小时后加入 DDP 2 .0μg/ m l,能明显抑制胃癌细胞增殖 ,流式细胞学可检测到凋亡峰 ,细胞受阻于G0 / G1 期 ,作用 4 8及 72小时的凋亡细胞百分率 (35 .1%、4 5 .7% )明显高于 N- ASODN组、PS- ASODN组、DDP组及 N- ASODN+DDP组 ,差异有显著性 (P<0 .0 5 )。其作用呈时间依赖性及序列特异性。结论　以端粒酶 RNA模板区为靶点的 PS- ASODN可促进 DDP诱导的胃癌细胞凋亡 ,对胃癌具有治疗价值     

RNA干扰在胃癌治疗中的研究进展

RNA干扰(RNAi)是近几年发展起来的一种新兴的基因沉默技术,他是由双链RNA介导的靶向基因序列特异性转录后沉默机制.目前,RNAi技术已被广泛应用于各种肿瘤研究,结果发现其可特异地抑制癌基因、癌相关基因或突变基因的过度表达,从而抑制肿瘤的发生、发展.同时RNAi技术在胃癌治疗方面也进行了许多积极的探索,取得了一些突破性进展.RNAi技术可直接作用于胃癌的靶向基因,也可通过抑制肿瘤血管新生间接治疗胃癌,并且他对胃癌化疗多药耐药也有作用.     

miR-107靶向PCDH17表达调控EMT通路抑制胃癌细胞迁移、侵袭的分子机制

目的 探讨微小RNA(miR)-107靶向原钙黏蛋白(PCDH)-17调控EMT通路影响胃癌细胞迁移、侵袭的作用机制.方法 采用实时荧光定量PCR(qRT-PCR)检测miR-107、PCDH17 mRNA在胃癌组织中表达;双荧光素酶报告基因系统检测miR-107对PCDH17转录活性的影响;胃癌MKN-28细胞转染pcDNA-PCDH17或siRNA-PCDH,Transwell迁移及侵袭实验检测PCDH17的表达对MKN-28细胞迁移及侵袭能力的影响;Western印迹检测PCDH17的表达对EMT通路的蛋白表达水平的影响.miR-107过表达验证细胞迁移及侵袭.结果 miR-107在胃癌组织中高表达,PCDH17在胃癌组织中低表达;过表达PCDH17后,细胞迁移及侵袭能力明显降低,E-Cadherin表达水平明显升高,而N-Cadherin、Vimentin表达水平明显降低;抑制PCDH17表达后,细胞迁移及侵袭能力明显增强,E-Cadherin表达水平明显降低,而N-Cadherin、Vimentin表达水平明显升高;双荧光素酶报告基因系统检测结果 显示,miR-107可直接调控PCDH17的转录活性;miR-107可通过负向调控PCDH17而促进EMT转化进而增强胃癌细胞迁移及侵袭能力.结论 miR-107靶向PCDH17表达从而调控胃癌细胞迁移及侵袭能力,其可能通过激活EMT通路而发挥作用.     

Influence of up-regulation of Notch ligand DLL4 on biological behaviors of human gastric cancer cells

AIM: To investigate the potential roles of Delta-like ligand 4 (DLL4) on the biological behavior of gastric cancer cells and its molecular mechanisms. METHODS: A recombinant eukaryotic expression vector containing human DLL4 gene was constructed and transfected into the human gastric cancer cell line SGC7901. Clones with up-regulated DLL4 were selected and amplified. The effect of DLL4 up-regulation on gastric cancer cell growth was assessed using cell growth assay. The migration and invasion were assessed using a transwell migration assay and matrigel invasion assay. Matrix metalloproteinases were detected using the zymogram technique. Cells were implanted subcutaneously into male BALB/c nu/nu mice. Tumor volumes were then calculated and compared. DLL4 staining in the implanted tumor was performed using immunohistochemistry technique. RESULTS: Growth curves over a six-day time course showed significantly promoted cell proliferation of SGC7901 cells with up-regulated DLL4. DLL4 up-regulation in SGC7901 cells promoted the migration (205.4 ± 15.2 vs 22.3 ± 12.1, P < 0.05) and invasion (68.8 ± 5.3 vs 18.2 ± 6.0, P < 0.05) in vitro and tumorigenicity in vivo (2640.5 ± 923.6 mm 3 vs 1115.1 ± 223.8 mm 3 , P < 0.05). Furthermore, significantly increased mRNA level and increased secretion of matrix metalloproteinase-2 (MMP-2) proenzyme were observed in SGC7901 cells with up-regulated DLL4. However, increased MMP-9 mRNA level but decreased extracellular MMP-9 proenzyme level was observed. CONCLUSION: Our observations indicated a mechanism by which activation of DLL4-mediated Notch signaling promotes the expression and secretion of MMP-2 proenzyme and influences the progress of gastric cancer.