miRNA-144抑制小鼠RAW264.7巨噬细胞ABCA1表达

目的构建miR-144真核表达载体,检测miR-144是否调控小鼠RAW264.7巨噬细胞三磷酸腺苷结合盒转运体A1(ABCA1)的表达。方法结合文献,通过预测软件分析,选取评分较高、可作用于ABCA1 mRNA 3'非编码区(ABCA1 mRNA3'UTR)的miR-144。通过分子克隆技术,利用PCR扩增miR-144和ABCA1 mRNA 3'UTR的DNA序列,酶切胶回收后,分别连接至真核表达载体pcDNA3.1(+)载体和pcDNA3.1(+)-luciferase载体上。测序后,运用双荧光素酶报告基因系统检测萤火虫荧光素酶的活性,观察miR-144是否对ABCA1 mRNA 3'UTR具有直接靶向作用。运用LipofectamineTM2000将pcDNA3.1(+)空载体、pcDNA3.1(+)-miR-144转染至小鼠RAW264.7巨噬细胞。通过实时定量PCR(qRT-PCR)检测转染后miR-144的表达含量。通过qRT-PCR和Western blot法检测过表达miR-144后ABCA1在mRNA和蛋白水平的变化。结果 miR-144 PCR产物连接至pcDNA3.1(+)载体上,ABCA1 mRNA 3'UTR连接至pcDNA3.1(+)-luciferase载体上,测序正确。运用双荧光素酶报告基因系统检测发现,和对照组[pcDNA3.1(+)空载体、pcDNA3.1(+)-luciferase-ABCA1 3'UTR和PRL-SV40联合转染]三者相比,实验组[pcDNA3.1(+)-miR144、pcDNA3.1(+)-luciferase-ABCA1 3'UTR和PRL-SV40联合转染]三者可以显著降低萤火虫荧光素酶的活性(P0.05),证明miR-144对ABCA1 mRNA3'UTR具有直接靶向作用。将pcDNA3.1(+)空载体、pcDNA3.1(+)-miR-144转染至小鼠RAW264.7细胞中,qRT-PCR结果显示,转染pcDNA3.1(+)空载体组miR-144表达无明显变化(P0.05);转染pcDNA3.1(+)-miR-144组中miR-144表达量显著增高(P0.01).qRT-PCR结果显示,转染pcDNA3.1(+)空载体和pcDNA3.1(+)-miR-144对ABCA1 mRNA表达水平无明显影响(P0.05),Western blot结果显示转染pcDNA3.1(+)-miR-144可以显著降低ABCA1蛋白水平的表达(P0.01)。结论 miR-144可以在转录后水平降低ABCA1蛋白的表达。     

miR-21真核表达载体的构建及其活性鉴定

目的:构建miR-21的真核表达载体, 并使其在骨肉瘤MG63细胞中表达, 为研究miR-21对骨肉瘤细胞MG63的作用打下基础.方法:根据miRNA的成熟序列以及附近约200多碱基共433个碱基序列, 设计PCR引物, PCR扩增, 退火后用T4连接到线性化的pcDNA3.1(+)质粒中, 并对重组质粒进行双酶切、菌落PCR及测序分析, 鉴定完全正确的重组质粒转染骨肉瘤细胞MG63, G418(400 mg/L)筛选4周获得miR-21稳定表达细胞系, 用Northern blot及real time RT-RCR法鉴定pcDNA3.1(+)-miR-21可在真核细胞中过表达.结果:成功构建了miR-21的真核表达载体, 并获得稳定转染重组质粒的细胞系.结论:miR-21的真核表达载体在骨肉瘤细胞MG63中稳定高表达, 为进一步研究miR-21在骨肉瘤MG63中的功能及基因调控机制奠定了实验基础.     

活化型肝星状细胞中miRNA-193下调α-平滑肌肌动蛋白的表达

目的:研究活化型肝星状细胞(HSC)中miRNA-193(miR 193)下调肝纤维化相关基因的表达。方法:将大鼠miR-193的前体序列(pre-miR-193)克隆到真核表达载体pcDNA3.1(+)中,经酶切和DNA测序鉴定,获得质粒pcDNA3.1-miR-193;通过脂质体转染法将质粒转染到大鼠的活化型肝星状细胞(HSC-T6)中,采用荧光素酶报告基因分析法和免疫印迹检测肝纤维相关基因的表达。结果:构建的真核表达载体pcDNA3.1-miR-193经酶切鉴定及DNA测序显示,目的片段的大小与预期结果一致;荧光素酶报告基因分析法和免疫印迹检测显示,重组质粒转染到活化型H-SC-T6中后,肝纤维化相关基因的α-平滑肌肌动蛋白(α-SMA)的表达呈明显下降趋势,而胶原蛋白Ⅰα1和Ⅰα2的下调作用不明显。结论:miR-193能抑制活化型肝星状细胞中肝纤维化相关基囚α-SMA的表达。     

LINC00341通过靶向miR-187对前列腺癌DU145细胞增殖、凋亡、迁移及侵袭的影响

目的 探讨LINC00341对前列腺癌DU145细胞增殖、凋亡、迁移、侵袭的靶向影响及机制。方法 将LINC00341过表达载体（pcDNA3.1-LINC00341）转染前列腺癌细胞DU145,检测细胞的增殖力、细胞凋亡及迁移和侵袭能力,蛋白质印记（Western blot）法检测Cyclin D1、P21、Bcl-2、Bax、MMP-2和E钙黏蛋白（E-cadherin）的表达。双荧光素酶报告实验联合RT-qPCR验证LINC00341对miR-187的靶向调控关系。将miR-187模拟物（miR-187 mimics）和pcDNA3.1-LINC00341共转染DU145细胞,采用上述方法检测细胞增殖、凋亡、迁移和侵袭能力变化。结果 过表达LINC00341抑制DU145细胞Cyclin D1、Bcl-2和MMP-2的表达,促进P21、Bax和E-cadherin蛋白的表达水平,抑制DU145细胞的增殖、迁移和侵袭,促进细胞凋亡。miR-187是LINC00341的靶基因,LINC00341靶向负性调控miR-187表达。过表达miR-187可逆转LINC00341过表达对DU1...     

密码子优化HPV16衣壳基因真核共表达载体的构建及细胞转染

目的:构建密码子优化的HPV16衣壳基因真核共表达载体pcDNA3.1-L1-IRES-L2.方法:用PCR技术从988载体中获得L1-IRES-L2片段,将该片段克隆到pCR -XL-TOPO 载体,然后定向亚克隆到pcDNA3.1( )真核表达载体中,从而构建真核共表达载体pcDNA3.1-L1-IRES-L2;通过水动力转染技术(hydrodynamics-based transfection)和脂质体细胞转染法(liposome-mediated transfection of cells),检测衣壳基因的体内、外转录情况;重组质粒转染后293T细胞后观察其形态变化,用Western blot方法检测293T细胞中L1衣壳蛋白的表达.结果:酶切和测序结果表明真核共表达载体pcD-NA3.1-L1-IRES-L2构建正确.重组质粒中的L1和L2基因在小鼠肝脏、293T细胞中均发生转录.重组质粒转染293T细胞后出现CPE(cytopathic effect)现象,表明衣壳基因在细胞中已表达.Western blot方法检测发现L1蛋白在293T细胞中表达.结论:成功地构建了pcDNA3.1-L1-IRES-L2共表达真核载体,为进一步研究HPV16感染机制奠定基础.     

HBV基因组各基因真核表达载体的构建及转染

目的 构建HBV基因组各基因真核表达载体,转染HepG2细胞,建立稳定转染的HepG2细胞系.方法 采用PCR方法,以HBV全基因组质粒为模板扩增HBV基因的各基因片段,利用DNA重组技术将其定向插入到真核表达载体pcDNA3.1( ),经酶切和测序鉴定后,用脂质体转染法转染HepG2细胞,通过G418筛选,建立稳定转染的HepG2细胞系,用细胞流式技术及细胞免疫组化技术检测HBV各基因产物在细胞内的表达.结果 成功构建了pcDNA3.1( )/HBs、pcDNA3.1( )/HBc、pcDNA3.1( )/HBe、pcDNA3.1( )/HBp、pcDNA3.1( )/HB-preS1、pcDNA3.1( )/HB-preS2、pcDNA3.1( )/HBx真核表达载体,并建立了稳定转染的HepG2细胞系,成功地表达目的 基因.结论 真核表达载体成功构建和稳定转染HepG2细胞系的建立为进一步研究各基因的功能奠定良好的实验基础.     

miR-30a在心肌梗死大鼠心肌纤维化中的作用机制及对心功能的影响

目的探讨miR-30a在大鼠心肌梗死后对心肌纤维化的作用机制及对心功能的影响。方法构建携带大鼠miR-30a基因的载体,在HEK293细胞中包装病毒载体r AAV9-miR-30a及阴性对照r AAV9-miR-30a-NC,提取纯化后通过冠脉注射方法分别传导PBS缓冲液、r AAV9-miR-30-NC和r AAV9-miR-30a至大鼠心脏,再建立大鼠心肌梗死模型,分别设为PBS组、miR-30-NC组和miR-30a组,同时设立假手术组(sham组)。用心脏彩色多普勒超声检测心功能指标,包括短轴缩短率(FS)及左室射血分数(LVEF);Masson染色观察心肌胶原容积分数(CVF);免疫组化法检测Ⅰ、Ⅲ型胶原表达;实时荧光定量PCR(real-time PCR)检测心肌miR-30a及TGF-β1和CTGF mRNA表达;蛋白印迹法(Western blot)检测TGF-β1及CTGF蛋白的表达。结果 miR-30a组心功能较PBS组及miR-30-NC组显著改善(P0.05)。miR-30a组的心肌CVF及Ⅰ、Ⅲ胶原表达水平、Ⅰ/Ⅲ型胶原比值较PBS组及miR-30-NC组显著降低(P0.01);miR-30a组心肌TGF-β1 mRNA及蛋白表达水平与PBS组及miR-30-NC组比较显著下降(P0.001);CTGF mRNA及蛋白表达水平较PBS组及miR-30-NC组显著降低(P0.001)。结论 miR-30a过表达能下调心肌梗死后心肌TGF-β1、CTGF mRNA及蛋白水平,从而减少心肌胶原产生,抑制心肌纤维化,进而改善心功能。     

miR-3960对成骨细胞分化的影响**☆

背景：成骨细胞的分化成熟过程涉及多种激素和细胞因子对成骨细胞分化相关基因表达的调控,近来发现多个微小RNAs也参与了这一调控过程。 目的：观察miR-3960在小鼠骨髓基质细胞向成骨细胞分化过程中的作用。 方法：将miR-3960表达载体pSilencer4.1-miR-3960转染骨髓基质细胞,构建miR-3960过表达细胞模型,随后予300 μg/L骨形态发生蛋白2诱导分化,观察成骨细胞分化指标变化。 结果与结论：转染pSilencer4.1-miR-3960能够在细胞中稳定地高表达miR-3960。miR-3960过表达促进骨髓基质细胞向成骨细胞分化过程中的碱性磷酸酶活性增高和骨钙素分泌,增加细胞中的钙沉积量。抑制miR-3960降低骨髓基质细胞向成骨细胞分化过程中的碱性磷酸酶活性,减少骨钙素分泌,降低钙沉积量。表明miR-3960可以促进成骨细胞分化。     

表达miR-10a的重组腺病毒的构建与鉴定

目的 构建表达miR-10a的重组腺病毒(adenovirus,Ad)载体.方法 用红色荧光蛋白mCherry基因替换穿梭质粒pDC316-EGFP-U6的增强型绿色荧光蛋白(enhanced green fluorescent protein,EGFP)报告基因.利用表达siRNA的策略,合成编码miR-10a的长链DNA序列,双链退火后克隆至pDC316-mCherry-U6获得pDC316-mCherry-U6-miR-10a.pDC316-mCherry-U6-miR-10a与骨架质粒pBHGlox△E1,3Cre共转染HEK293细胞,包装成复制缺陷型重组腺病毒Ad-miR-10a,空斑形成实验纯化、扩增、滴定重组腺病毒.Ad-miR-10a感染HeLa细胞后在荧光显微镜下观察mCherry表达,用RT-qPCR检测miR-10a表达.结果 构建的pDC316-mCherry-U6-miR-10a序列正确,荧光显微镜下可见mCherry的表达,重组腺病毒Ad-miR-10a滴度为1.8 × 107pfu/mL,感染HeLa细胞后miR-10a表达较mock高40倍.结论 成功构建了表达miR-10a的重组腺病毒,siRNA表达策略可用于miRNA的人工表达.

Abstract：

Objective To develop a miR-10a-expressing recombinant adenoviral vector. Methods The EGFP gene in shuttle plasmid pDC316-EGFP-U6 was replaced by red fluorescent protein mCherry gene. Long DNA sequence coding miR-l0a was synthesized. After annealing, the double-stranded miR-10a-coding sequence was inserted into pDC316-mCherry-U6. The resultant pDC316-mCherryU6-miR-10a was co-transfected with adenoviral skeleton plasmid pBHGlox△E1, 3Cre into HEK293 cells. The replication-defective adenovirus Ad-miR-10a was purified, amplified, and tittered by plaque assay. The mCherry expression was detected by fluorescence microscope. The expression of miR-10a by Ad- miR- 10 a in HeLa cells was determined by RT-qPCR. Results The sequence of pDC316-mCherryU6-miR-10 a was confirmed by restriction enzyme digestion and sequencing. mCherry expression could be detected under fluorescence microscope. The titers of Ad-miR-10a was 1.8 × 107 pfu/mL, and the level of miR-10a expression in HeLa cells infected with Ad-miR-10a was 40 times higher than that with Admock. Conclusion A miR-10a-expressing recombinant adenovirs Ad-miR-10a has been successfully constructed. The strategy for artificial expression of siRNA is applicable for expression of miRNA.     

SNHG3调控miR-186对过氧化氢处理的血管内皮细胞损伤的影响北大核心CSCD

目的:探讨小核仁RNA宿主基因3(SNHG3)对过氧化氢(H_(2)O_(2))处理的血管内皮细胞损伤的影响及分子机制。方法:将Eahy926细胞分为对照组(不做任何处理)、H_(2)O_(2)组(500 mmol/L H_(2)O_(2))、H_(2)O_(2)+pcDNA3.1组(转染pcDNA3.1+500 mmol/L H_(2)O_(2))、H_(2)O_(2)+pcDNA3.1-SNHG3组(转染pcDNA3.1-SNHG3+500 mmol/L H_(2)O_(2))、H_(2)O_(2)+pcDNA3.1-SNHG3+miR-NC组(转染pc-DNA3.1-SNHG3和miR-NC+500 mmol/L H_(2)O_(2))、H_(2)O_(2)+pcDNA3.1-SNHG3+miR-186组(转染pcDNA3.1-SNHG3和miR-NC+500 mmol/L H_(2)O_(2))。RT-qPCR检测SNHG3和miR-186表达;四甲基偶氮唑盐比色法(MTT)检测细胞存活率;超氧化物歧化酶(SOD)和乳酸脱氢酶(LDH)试剂盒分别检测细胞SOD活性和培养液LDH含量;流式细胞术检测细胞凋亡;荧光素酶报告实验检测SNHG3和miR-186的靶向关系。结果:与对照组相比,H_(2)O_(2)处理的Eahy926细胞中SNHG3表达、存活率、SOD活性显著降低,LDH水平、细胞凋亡率显著升高(P<0.05)。过表达SNHG3,H_(2)O_(2)处理的Eahy926细胞存活率、SOD活性显著升高,LDH水平、细胞凋亡率显著降低(P<0.05)。SNHG3靶向调控miR-186表达,过表达miR-186逆转了SNHG3对H_(2)O_(2)处理的Eahy926细胞活性、凋亡及SOD、LDH的影响。结论:过表达SNHG3可促进H_(2)O_(2)处理的Eahy926细胞存活,抑制细胞凋亡,提高SOD活性,降低LDH水平,对H_(2)O_(2)诱导的Eahy926细胞损伤具有保护作用,其机制可能与miR-186有关。     

CircCBFB is a mediator of hepatocellular carcinoma cell autophagy and proliferation through miR-424-5p/ATG14 axis

This study aims to investigate the role of circCBFB in hepatocellular carcinoma (HCC) cell proliferation and autophagy. qRT-PCR and Western blotting analyses quantified the expression levels of circCBFB, miR-424-5p, and ATG14 in HCC tissues and/or HCC cell lines. After transfection with pcDNA3.1-CircCBFB, sh-CircCBFB, miR-424-5p mimic, miR-424-5p inhibitor, pcDNA3.1-ATG14, sh-ATG14, sh-CircCBFB?+?miR-424-5p inhibitor, pcDNA3.1-CircCBFB?+?miR-424-5p mimic, sh-CircCBFB?+?pcDNA3.1-ATG14, or pcDNA3.1-CircCBFB?+?sh-ATG14, the proliferation, cell cycle, and apoptosis of Huh-7 and HCCLM3 cells were detected, respectively, through MTT assay and flow cytometry. Western blotting measured the expression levels of ATG14 and autophagy-related proteins (LC3-ΙΙ/LC3-Ι, Beclin1, and p62). The interactions among circCBFB, miR-424-5p, and ATG14 were identified through RNA fluorescence in situ hybridization and RNA immunoprecipitation. In HCC tissues, circCBFB and ATG14 were highly expressed, and miR-424-5p expression was downregulated. Transfection of pcDNA3.1-CircCBFB, miR-424-5p inhibitor, or pcDNA3.1-ATG14 into HCC cells facilitated HCC cell proliferation and autophagy, while suppressing cell apoptosis, evidenced by elevated cell viability, increased protein levels of autophagosome markers (LC3-ΙΙ/LC3-Ι and Beclin1), repressed apoptosis rate, and suppressed protein level of autophagy receptor p62. miR-424-5p was a target gene of circCBFB, and miR-424-5p negatively mediated ATG14. CircCBFB inhibits miR-424-5p and upregulates ATG14, thus promoting HCC cell proliferation and autophagy.

     

Upregulation of miR‑95-3p inhibits growth of osteosarcoma by targeting HDGF

Osteosarcoma is the most common bone malignancy and miR-95-3p plays an important role in multiple cancers. The purpose of this study was to explore the effect and potential mechanism of miR-95-3p on the growth of osteosarcoma. In vitro, the osteosarcoma cell lines, SAOS-2 and U2OS cells, were transfected with miR-95-agomir to assess the role of miR-95-3p in proliferation and apoptosis of osteosarcoma cells. We determined that overexpression of miR-95-3p significantly attenuated cell proliferation but enhanced apoptosis in SAOS-2 and U2OS cells. We also found that overexpression of miR-95-3p in osteosarcoma cells downregulated the expression of hepatoma-derived growth factor (HDGF). Next, knockdown of HDGF by siRNA targeting HDGF clearly inhibited cell proliferation and induced apoptosis in U2OS cells. In vivo, a tumor formation assay in BALB/c nude mice was conducted by injecting the pre-miR-95 or control vector lentivirus-infected U2OS cells to determine the effect of miR-95-3p on the growth of osteosarcoma. Results showed miR-95-3p overexpression inhibited the osteosarcoma growth and downregulated the HDGF expression in xenografted tumor. For mechanism study, we co-transfected HDGF/pcDNA3.1 plasmid and miR-95-agomir to U2OS cells, and we demonstrated that overexpression of HDGF could attenuate the effects of miR-95-3p on U2OS cell proliferation, apoptosis and migration. These findings indicated that miR-95-3p might act as a potential tumor suppressor in osteosarcoma by targeting HDGF. Thus, miR-95-3p may become a potential therapeutic in treatment of osteosarcoma.     

miR-211通过靶向调控TFAM抑制人乳腺癌细胞系增殖

目的探讨miR-211靶向线粒体转录因子A(TFAM)对人乳腺癌细胞增殖的影响。方法用miR-211及TFAM作为研究对象。首先,在乳腺癌细胞中转染miR-211 mimics或miR-211抑制剂以实现miR-211过表达或miR-211沉默,并检测miR-211过表达或沉默时TFAM蛋白质的表达水平;其次,构建了在TFAM的5'端有或无6对碱基突变的荧光酶报告基因质粒(mut-TFAM/wt-TFAM),与miR-211 mimics或miR-211抑制剂共转染后检测荧光酶活性变化;然后,构建pc DNA3.1/TFAM质粒,与miR-211 mimics或miR-211抑制剂共转染后检测TFAM蛋白质表达水平变化;最后,检测pc DNA3.1/TFAM和mimics NC/miR-211 mimics共转染后乳腺癌细胞增殖的增殖。结果miR-211过表达抑制TFAM蛋白质表达(P0.01),miR-211沉默促进TFAM蛋白质表达(P0.01);miR-211可靶向结合TFAM调控其表达;pc DNA3.1/TFAM可实现TFAM过表达(mRNA P0.01,蛋白质P0.01),并可恢复miR-211对TFAM的抑制作用;miR-211可抑制乳腺癌细胞的增殖和增殖(P0.05),TFAM可促进乳腺癌细胞增殖增殖(P0.01),TFAM可回复miR-211对乳腺癌细胞增殖增殖的抑制作用(P0.05)。结论 miR-211靶向TFAM基因抑制人乳腺癌细胞的增殖。     

CircAGFG1 acts as a sponge of miR-4306 to stimulate esophageal cancer progression by modulating MAPRE2 expression

ObjectiveThis work aims to determine the role of circular RNA (circRNA) AGFG1 and related molecular mechanism in esophageal squamous cell carcinoma (ESCC) cells.MethodsCircAGFG1 expression in ESCC cell lines was probed with qRT-PCR. ESCC cells were transfected/cotransfected with si-circAGFG1, pcDNA3.1-circAGFG1, si-Microtubule Associated Protein RP/EB Family Member 2 (MAPRE2), pcDNA3.1-circAGFG1 + miR-4306 mimic or pcDNA3.1-circAGFG1 + si-MAPRE2. The interactions between circAGFG1 and miR-4306 as well as miR-4306 and MAPRE2 were confirmed by dual-luciferase reporter assay. Cell proliferation, migration and invasion were detected by CCK-8, cell scratch and Transwell assays, respectively. Relative RNA expression levels of circAGFG1, miR-4306 and MAPRE2 in ESCC cells were measured by qRT-PCR. The protein level of MAPRE2 in ESCC cells was monitored by Western blot.ResultsCircAGFG1 was observably upregulated in ESCC cell lines. Besides, circAGFG1 silencing hindered ESCC cell development in vitro, and these effects were enhanced by miR-4306 overexpression or MAPRE2 silencing. Mechanistic analysis evidenced that circAGFG1 might act as a competitive endogenous RNA of miR-4306 to relieve the repressive effect of miR-4306 on its target MAPRE2.ConclusionCircAGFG1 facilitates ESCC progression via the miR-4306/MAPRE2 axis, and it may act as a possible biomarker for therapy and diagnosis in ESCC treatment.     

miR-24通过SIRT1调控晶状体上皮细胞凋亡的研究

目的探讨氧化应激情况下miR-24对晶状体细胞凋亡的调控。方法采用实时定量PCR检测40例白内障患者晶状体上皮组织及临近晶状体上皮组织中miR-24的表达水平,并在氧化应激情况下检测miR-24的表达变化。通过miR-24 mimics、miR-24 inhibitor转染晶状体上皮细胞SAR01/04以过表达和敲低miR-24,利用pcDNA3.1-SIRT1转染SAR01/04以过表达SIRT1,FITC/PI流式细胞术检测晶状体细胞凋亡情况,Western blot检测凋亡相关蛋白Bcl-2、Bax表达情况,CCK-8检测细胞活性状态。结果miR-24在白内障晶状体上皮组织中的表达高于临近组织,氧化应激情况下促进miR-24表达增高,差异有统计学意义(P<0.05);氧化应激情况下,敲低miR-24抑制晶状体上皮细胞的凋亡;过表达或敲低miR-24可以分别降低或促进SIRT1的表达;过表达miR-24和过表达SIRT1后抑制了晶状体细胞的凋亡。结论氧化应激促进晶状体上皮细胞miR-24表达上调,miR-24通过下调SIRT1促进晶状体上皮细胞的凋亡,为白内障的靶向治疗提供一定的策略。     

miR-21通过靶向FasL基因对脑胶质瘤细胞生长的影响

目的:探讨脑胶质瘤细胞中miR-21对Fas L表达的调控作用以及对细胞生长和凋亡的影响,并研究其分子作用机制。方法:将miR-21模拟物(miR-21 mimics)、miR-21抑制物(miR-21 inhibitor)以及阴性对照(scramble)瞬时转染到U251细胞中,CCK-8法和流式细胞术检测细胞活力和凋亡情况。构建Fas L 3’UTR双萤光素酶报告载体,通过采用双萤光素酶报告实验验证miR-21的靶基因。构建表达载体pc DNA3.1-Fas L,回复实验分析miR-21对细胞凋亡的影响。结果:miR-21过表达可促进U251细胞的活力,抑制细胞凋亡;miR-21表达下调则抑制细胞活力,促进细胞凋亡,和对照组比较差异有统计学意义(P0.05)。双萤光素酶报告实验和回复实验结果提示miR-21可以通过作用于Fas L的3’UTR区,负向调控其表达,从而抑制细胞的凋亡。结论:miR-21可以通过靶向调控Fas L的表达进而促进U251细胞的生长。     

miR-200c阻滞转化生长因子-β1在腹膜后成纤维细胞增殖和迁移侵袭中的作用

目的：阐明miR-200c对腹膜后成纤维细胞增殖的影响,并分析其分子机制,为抑制腹膜后纤维化提供理论依据。方法：收集36例人腹膜后组织,原代培养成纤维细胞,以5 ng/ml TGF-β1刺激者为TGF-β1组,pcDNA3-1-miR-200c转染成纤维细胞,再给予5 ng/ml TGF-β1刺激者为miR-200c组,仅以pcDNA3-1质粒转染者为pcDNA3-1质粒组,正常培养的成纤维细胞为对照组。分别以噻唑蓝（MTT）细胞增殖实验、细胞划痕实验、Transwell细胞小室迁移实验检测成纤维细胞增殖和迁移能力,并以ELISA实验检测各组细胞裂解液中Akt蛋白的含量。结果：miR-200c组成纤维细胞的增殖OD值明显比TGF-β1组降低（P＜0.01）;与TGF-β1组相比,miR-200c组细胞迁移率明显降低（P＜0.01）;miR-200c组Akt蛋白的含量比TGF-β1组明显降低（P＜0.01）。结论：miR-200c下调Akt通路而抑制TGF-β1对成纤维细胞的增殖或迁移效果,对抑制腹膜纤维化具有重要意义。     

Survivin-2B诱导人乳腺癌细胞凋亡的初步研究*

 目的：探讨存活蛋白2B (survivin-2B)在诱导肿瘤细胞凋亡中的分子机制。方法：将survivin-2B基因插入真核表达载体pCDNA3.1,得到重组载体pCDNA3.1-survivin-2B。将空载体pCDNA3.1及重组载体pCDNA3.1-survivin-2B分别转染人乳腺癌细胞株MCF7,转染后48 h,用annexin V/7-AAD染色法分析细胞凋亡情况,利用碘化丙啶染色法分析转染对细胞周期的影响;同时提取总RNA并反转录成cDNA,进行多重聚合酶链反应。利用GeXP多基因表达分析系统检测21个与肿瘤相关基因的表达情况。结果：过表达survivin-2B基因导致MCF7细胞凋亡与细胞周期阻滞,并引起8个基因表达上调,2个基因表达下调。变化最大的为醛脱氢酶4家族成员A1（ALDH4A1）,表达下降48%;变化最小的为胞质分裂调控蛋白1（PRC1）,上调1.08倍。结论：Survivin-2B能够诱导细胞凋亡与细胞周期G2/M期阻滞,并引起部分肿瘤相关基因的表达变化。     

A brain-targeted rabies virus glycoprotein-disulfide linked PEI nanocarrier for delivery of neurogenic microRNA

Recent advances in efficient microRNA (miRNA) delivery techniques using brain-targeted nanoparticles offer critical information for understanding the functional role of miRNAs in vivo, and for supporting targeted gene therapy in terms of treating miRNA-associated neurological diseases. Here, we report the rabies virus glycoprotein (RVG)-labeled non-toxic SSPEI nanomaterials capable of neuron-specific miR-124a delivery to neuron in vivo. The RVG-labeled BPEI-SS (RVG-SSPEI) nanocarrier showed less toxicity in acetylcholine receptor-positive Neuro2a cells, and electrostatic interaction of RVG-SSPEI with miR-124a exhibited optimal transfection efficacy. The RVG-SSPEI polymer specifically targeted Neuro2a using cy5.5-miR-124a mixed with RVG-SSPEI. The functional action of miR-124a oligomers released from polyplexes in the cytoplasmic region was evaluated by a reporter vector containing a miR-124a -binding sequence, and showed a significantly reduced reporter signal in a dose-dependent manner. Cy5.5-miR-124a/RVG-SSPEI- injected into mice via tail veins displayed the enhanced accumulation of miR-124a in the isolated brain. Hindrance of the efficient penetration of neuronal cells by size limitation of the miR-124a/RVG-SSPEI improved with the help of mannitol through blood-brain barrier disruption. These findings indicated that the RVG peptide combined with mannitol infusion using SSPEI polymer for neuron-specific targeting in vivo is sufficient to deliver neurogenic microRNA into the brain.     

c-Myc-activated long non-coding RNA H19 downregulates miR-107 and promotes cell cycle progression of non-small cell lung cancer

To verify c-Myc can regulate the expression of lncRNA H19 directly in non-small cell lung cancer (NSCLC) and clarify the molecular mechanism on how lncRNA H19 promote the cell cycle progression of NSCLC. The mRNA levels of lncRNA H19 in NSCLC tissues and cells, the adjacent tissues and normal cells were determined by RT-PCR. The expression change of lncRNA H19 in NSCLC cells after transfection with pcDNA3.1-c-Myc or c-Myc-siRNA was determined by RT-PCR, respectively. Targeted role of c-Myc on the promoter of H19 was studied by luciferase reporter assay. Chromosome immune coprecipitation (ChIP) was used to confirm the relationship between c-Myc and H19. MiRNAs that have base-pairing with H19 was predicted by online software. The relationship between H19 and miR-107 was determined by disturbing and overexpressing the expression of H19. The influence of the changes of H19 and miR-107 on cell cycle progression was determined by flow cytometry. The mRNA levels of lncRNA H19 in NSCLC tissues and cells were significantly higher than the adjacent tissues and normal cells, respectively. The expression of H19 increased or decreased accordingly with the overexpression and knockdown of c-Myc. The activity of the promoter of H19 was strengthened by c-Myc. While the expression of miR-107 increased or decreased with the overexpression and knockdown of H19, respectively. The number of cells in G2/M stage decreased significantly with the knockdown of H19 and miR-107 compared with the control group. Our study demonstrates that lncRNA H19, which is induced by c-Myc, is up-regulated in NSCLC. H19 influences the mitotic progression of NSCLC cell lines.