miR-34a通过Notch信号通路影响乳腺癌细胞的生物学行为

目的探讨miR-34a通过Notch信号通路影响乳腺癌细胞的生物学行为。方法乳腺癌细胞MCF-7分为miR-34a及Control组,分别利用脂质体转染miR-34a mimics及miR-34a NC,RT-PCR法检测细胞中miR-34a表达,MTT、Hoechst染色及transwell法分别检测细胞活力、凋亡及侵袭情况;western blot检测细胞中Notch1,Notch2,Dll1及Jagged-1蛋白表达情况。结果与Control组比较,miR-34 mimics组中miR-34a表达量上调,细胞皱缩,变圆变亮,细胞活力降低(P0.01),细胞凋亡率显著提高(P0.01),细胞侵袭数目减少(P0.01),Notch1,Notch2,Dll1及Jagged-1蛋白表达量都显著降低(P0.01)。结论 miR-34a mimics通过抑制Notch信号通路进而诱导MCF-7乳腺癌细胞凋亡并抑制其侵袭。     

miR-34a靶向调控SOX7表达抑制垂体腺瘤细胞增殖

探讨miR-34a通过靶向调控SOX7表达对垂体腺瘤细胞增殖的影响。结果显示,miR-34a mimics转染组和siRNA-SOX7组细胞活力、S期、G2期分别低于NC-miR-34a转染组和NC-SOX7转染组,细胞凋亡率和G1期分别高于NC-miR-34a转染组和NC-SOX7转染组。miR-34a mimics转染组SOX7 mRNA、SOX7蛋白的相对表达量低于NC-miR-34a转染组。结果表明,miR-34a可以通过靶向抑制SOX7表达抑制垂体腺瘤细胞增殖。     

miR-34a通过靶向抑制Notch信号通路减轻糖尿病肾病小鼠的足细胞损伤

目的 探讨miR-34a介导Notch信号通路对糖尿病肾病（DN）足细胞损伤及凋亡的影响。方法 体外实验：通过RT-PCR法检测高糖（30 mmol/L）环境下足细胞中miR-34a表达水平,构建miR-34a过表达足细胞系（miR-34a组）及其阴性对照（miR-NC组）,使用荧光素酶实验验证miR-34a与Notch 1的靶向关系,构建Notch 1过表达足细胞系（Notch 1组）和miR-34a、Notch 1均表达升高细胞系（miR-34+Notch 1组）;采用CCK-8法检测足细胞存活情况,流式细胞法检测细胞凋亡情况,Western blot法检测细胞凋亡关蛋白水平。体内实验：通过高脂饮食和链脲佐菌素建立DN小鼠模型并分为模型组、miR-34a组（n=15/组）,另选15只不做干预小鼠为对照组,miR-34a组和模型组小鼠分别尾静脉注射agomir-34a[80 mg/(kg·d)]、agomir-NC[80 mg/(kg·d)],连续注射3 d,4周后,HE染色、TUNEL法分别观察肾组织病理、凋亡情况,Western blot检测肾组织凋亡相关蛋白和Notch 1蛋白...     

miR-34a通过靶向抗凋亡基因Survivin抑制皮肤鳞状细胞癌增殖的研究

[摘要]　目的　研究miR-34a在皮肤鳞状细胞癌(SCC)中的表达及对肿瘤细胞增殖、抗凋亡的调控作用及机制。　方法　采用实时定量PCR检测46例SCC病人肿瘤组织及15例正常皮肤组织中miR-34a及Survivin的表达;将miR-34a mimic转染进皮肤鳞状细胞癌A431细胞系,探讨miR-34a对SCC细胞增殖、Survivin表达的影响;评估miR-34a及Survivin表达对SCC预后的生物诊断价值。 　结果　　（1）低分化SCC患者miR-34a显著低于高分化组,而Survivin则显著高于高分化组（P均<0.05）。与正常皮肤比较,SCC病人的miR-34a显著降低,而Survivin表达则显著提高,P值分别为0.0013及<0.0001,差异均有极显著性意义。（2）与未转染组相比,miR-34a mimic可以显著抑制A431细胞增殖（P<0.05）;同时显著降低Survivin蛋白表达（P<0.01）。（3）高miR-34a表达的SCC患者生存率显著高于低表达者,P=0.020567;高Survivin表达的SCC患者生存率则显著低于高表达者,P=0.008198。　结论　　miR-34a可通过对Survivin表达调控影响SCC细胞增殖,同时它也可作为一个很好的生物学诊断指标为评估SCC病人预后提供参考。     

MicroRNA-34a通过下调Notch1的表达促进心肌细胞凋亡

目的：探讨microRNA-34a（miR-34a）对心肌细胞凋亡的影响及其机制。方法：体外培养大鼠心肌细胞H9C2,分别转染miR-34a mimics、miR-34a inhibitor、随机合成的miR-NC片段、Notch1的siRNA、随机合成的siRNA-NC片段,将实验分为6 组：normal组、miR-34a组、miR-inhibitor组、miR-NC组、miRinhibitor+siRNA-Notch1组和miR-inhibitor+siRNA-NC组。RT-qPCR检测各组miR-34a的表达量,Westernbolt技术检测各组中caspase-3 和Notch1的表达量,流式细胞技术检测各组细胞的凋亡率。双荧光素酶报告实验鉴定Notch1为miR-34a的靶基因。结果：双荧光素酶报告实验证实miR-34a和Notch1间存在靶向关系。与miR-NC组比较,miR-34a组的miR-34a和caspase-3的表达量明显增多,Notch1的表达量明显减少,细胞凋亡率明显升高（P ＜0.01）。与miR-NC组比较,miR-inhibitor组的miR-34a和caspase-3的表达量明显减少,Notch1的表达量明显增多,细胞凋亡率明显减低（P ＜0.01）。与miR-inhibitor+siRNA-NC组比较,miRinhibitor+siRNA-Notch1组的Notch1的表达量明显降少,caspase-3的表达量明显减少,细胞凋亡率明显减低（P ＜0.01）。结论：miR-34a促进心肌细胞凋亡,其作用机制与靶向负调控Notch1有关。     

miR-195调控人乳腺癌细胞MCF-7增殖与凋亡的作用及机制研究

目的 研究miR-195调控人乳腺癌细胞MCF-7(MCF-7)增殖与凋亡作用及机制.方法 体外培养正常乳腺上皮细胞MCF-10A(MCF-10A)和MCF-7,qRT-PCR检测miR-195表达,蛋白质免疫印迹(WB)检测蛋白磷酸酶1D(PPM1D)蛋白表达.MCF-7瞬时转染,3-(4,5-二甲基噻唑-2)-2,...     

miR-34a-5p下调Notch1表达增强三阴性乳腺癌MDA-MB-231细胞对紫杉醇的敏感性

目的:本研究旨在阐明miR-34a-5p是否通过下调Notch1表达,进而增强三阴性乳腺癌MDA-MB-231细胞对紫杉醇的化疗敏感性.方法:qRT-PCR测定MCF-10A细胞与MDA-MB-231细胞miR-34a-5p的表达水平;以miR-34a mimic瞬时转染MDA-MB-231细胞,qRT-PCR与wes...     

miRNA-191对人乳腺癌细胞增殖、侵袭的影响

目的探讨miR-191在人乳腺癌细胞中的表达情况,研究其对乳腺癌细胞的增殖、侵袭的影响。方法 real-time PCR检测乳腺癌细胞[MDA-MB-231(雌激素受体阴性,ER-)、MCF-7(雌激素受体阳性,ER+)]和正常乳腺上皮细胞(HBL-100)中miR-191表达水平的差异;利用Lipofectamine2000将miR-191抑制体瞬时转染乳腺癌MCF-7,并用real-time PCR检测转染效果;分别用CCK-8法检测MCF-7细胞增殖,流式细胞术检测MCF-7细胞的细胞周期,Transwell法检测MCF-7细胞的侵袭能力。结果与正常乳腺细胞相比,miR-191在乳腺癌细胞中高表达(P<0.01),且在ER(+)乳腺癌细胞MCF-7中的表达水平高于ER(-)乳腺癌细胞MDA-MB-231(P<0.01),转染miR-191抑制体后,MCF-7细胞增殖能力(0.65±0.04)较阴性对照组(1.18±0.05)明显受到抑制(F=122.238,P<0.01),侵袭能力(56.67±2.58)较阴性对照组(82.5±5.79)减弱(F=18.734,P<0.01),G0/G1期的细胞比例(73.39±1.10)%较阴性对照组(69.28±2.11)%增加(F=61.060,P<0.01),S期细胞比例(20.9±1.17)%较阴性对照组(25.48±1.19)%减少(F=46.937,P<0.01)。结论 miR-191在人乳腺癌细胞中,特别是ER(+)乳腺癌中高表达,转染miR-191抑制体后,MCF-7细胞增殖、侵袭能力明显受到抑制。     

m iR-335通过靶向生存素对乳腺癌细胞增殖的调控作用

目的：探讨miR‐335通过靶向生存素对乳腺癌细胞增殖的调控作用。方法（1）选取乳腺癌组织及癌旁正常组织,分别采用RT‐PCR、Western blot检测组织中 miR‐335及生存素蛋白表达。（2）选取乳腺癌细胞系 MCF‐7,分别转染 miR‐335 mimic及mimic对照组,采用RT‐PCR、Western blot检测组织中miR‐335及生存素蛋白表达。（3）选取乳腺癌细胞系MCF‐7,分别将野生型survivin 3′‐UTR质粒（survivin‐wt）和突变型survivin 3′‐UTR质粒（survivin‐Mut）与miR‐335 mimic或模拟物阴性对照（NC）共转染至乳腺癌细胞系MCF‐7,双荧光素酶报告基因检测细胞荧光素酶活性。（4）选取乳腺癌细胞系MCF‐7,分别转染mimic对照组、miR‐335 mimic及miR‐335 mimic＋survivin ,采用四甲基偶氮唑蓝（MTT）法检测各组细胞增殖活性。结果（1）与癌旁组织相比较,乳腺癌组织中miR‐335表达显著降低（P＜0．05）,同时生存素蛋白表达显著增高（P＜0．05）。（2）与转染mimic对照组相比较,转染miR‐335 mimic可使乳腺癌细胞MCF‐7中miR‐335表达上调（P＜0．05）,同时生存素蛋白表达表达下调（P＜0．05）。（3）与转染NC相比较,共转染miR‐335 mimic与survivin‐wt可使MCF‐7荧光素酶活性降低（P＜0．05）,而共转染miR‐335 mimic与survivin‐Mut则MCF‐7荧光素酶活性无显著性变化（P＞0．05）。（4）转染miR‐335mimic后,MCF‐7增殖活性较转染mimic对照组显著降低（P＜0．05）;而转染miR‐335 mimic＋survivin后,MCF‐7增殖活性较单纯转染miR‐335 mimic显著提高（P＜0．05）,但仍显著低于转染mimic对照组（P＜0．05）。结论在乳腺癌组织中miR‐335呈现低表达,生存素呈现高表达;而miR‐335可通过靶向生存素抑制乳腺癌细胞系MCF‐7增殖。     

miR-34a在膀胱癌细胞中的表达及对细胞的增殖、迁移的影响

目的:探究在膀胱癌细胞中miR-34a的表达及对细胞的增殖、迁移的影响。方法:在ATCC细胞库购买膀胱癌细胞株,随机分为3组,miR-34a组通过转染方法将miR-34a mimics转染到膀胱癌细胞中;膀胱癌组(BC组)单纯膀胱癌细胞株不做其他处理,正常培养;抑制组(IN组)将miR-34a inhibitor转染到膀胱癌细胞株中。通过TUNEL法、CCK-8法、克隆实验、Transwell分析3组膀胱癌细胞凋亡、增殖、迁移、侵袭情况的差异性来探究在膀胱癌细胞中miR-34a的表达及对细胞的增殖的影响。结果:结果显示,IN组癌细胞内的miR-34a mRNA表达量最低,miR-34a组癌细胞内的miR-34a mRNA表达量最高,IN组和BC组、miR-34a组相比较miR-34a mRNA含量下降,说明转染成功(P<0.05)。IN组癌细胞凋亡数量最少,miR-34a组癌细胞大量凋亡,IN组和BC组、miR-34a组相比较癌细胞分布明显稀疏,数量明显减少(P<0.05)。组间两两比较发现IN组和miR-34a组之间OD值具有明显差异,IN组癌细胞的增殖数量最多,miR-34a组癌细胞的增殖数量最少,IN组显著高于BC组,BC组癌细胞的生长情况显著高于miR-34a组(P<0.05)。对3组癌细胞进行克隆迁移实验。由结果明显可知,IN组癌细胞迁移能力强,显微镜下细胞数量多(P<0.05),IN组和BC组、miR-34a组相比较整体迁移能力明显增强,癌细胞数量明显增多(P<0.05)。由结果明显可知,IN组膀胱癌细胞侵袭能力强,miR-34a组膀胱癌细胞显微镜下细胞数量少,侵袭能力弱(P<0.05),IN组和CO组、miR-34a组相比较,数量显著上升,整体侵袭能力增强(P<0.05)。结论:在膀胱癌细胞中,过表达的miR-34a能够抑制癌细胞生长,降低miR-34a的水平含量可以促进膀胱癌细胞的增殖。     

miR-205慢病毒表达载体的构建及其对乳腺癌细胞作用的初步研究

目的 构建micoRNA-205(miR-205)慢病毒表达载体,感染乳腺癌细胞MB231,建立稳定表达miR-205的MB231细胞株,观察其增殖能力的变化.方法 酶切慢病毒载体GV369,设计并合成miR-205引物,通过PCR扩增目的基因连接到慢病毒载体上.对重组质粒双酶切鉴定,进行慢病毒hsa-miR-205的包装和滴度测定.用构建好的慢病毒感染MB231细胞,定量PCR检测细胞中miR-205表达水平的变化,MTT和划痕实验观察过表达miR-205后MB231细胞增殖和迁移能力的变化.结果 测序显示,目的基因连接慢病毒载体成功.慢病毒稳定感染了MB231,定量PCR结果显示,感染hsa-miR-205的MB231中miR-205表达明显提高,MTT和划痕实验结果显示感染后MB231的细胞增殖和迁移能力受到抑制.结论 成功构建了miR-205慢病毒表达载体,并建立了稳定表达miR-205的细胞株MB231,显示其可能负调控乳腺癌细胞的恶性生物学行为,为后期进一步研究miR-205的功能和机制奠定了基础.     

Inhibitory effects of microRNA-34a on cell migration and invasion of invasive urothelial bladder carcinoma by targeting notch1

MicroRNAs (miRNAs or miRs) are a class of short, non-coding RNAs that participate in various oncological processes. This study aims to explore the roles of microRNA-34a (miR-34a) in invasive urothelial bladder carcinoma. miR-34a was transfected into bladder cancer cell lines 253J and J82. The miR-34a expression levels in tissues and cells were detected by using qRT-PCR. The Notch1 expression was detected by qRT-PCR and Western blotting. Cell migratory and invasive abilities were measured by Transwell chamber assay. Bioinformatics and luciferase assay were performed to predict and analyze the binding sites between miRNA-34a and Notch1. It was found that there was aberrant expression of miR-34a in bladder cancer tissues. Moreover, we revealed that ectopic expression of miR-34a suppressed cell migration and invasion, while forced expression of Notch1 increased cell migratory and invasive abilities. Finally, we observed that miR-34a transfection significantly down-regulated luciferase activity and reduced the mRNA and protein levels of Notch1. Our study concluded that microRNA-34a antagonizes Notch1 and inhibits cell migration and invasion of bladder cancer cells, which indicates the tumor-suppressive function of microRNA-34a in bladder cancer.     

MiR-181a靶向RASSF1A促进骨肉瘤细胞的生长和转移

目的：探讨miR-181a是否靶向调控抑癌基因RAS相关区域家族1A(Ras-association domain family 1,isoform A,RASSF1A),从而促进骨肉瘤细胞的生长和转移。方法：采用real-time PCR检测30例人骨肉瘤组织及其癌旁正常骨组织中miR-181a的表达,并分析miR-181a表达水平与骨肉瘤患者临床病理特征的相关性。在骨肉瘤细胞MG-63中瞬时转染miR-181a模拟物和miR-181a抑制剂,分别采用MTT和transwell检测miR-181a对骨肉瘤细胞生长和转移的作用。随后,预测并通过双荧光素酶报告基因验证miR-181a与RASSF1A基因3'-非编码区(3'-untranslated region,3'-UTR)的特异性结合作用。结果：与癌旁正常骨组织比较,miR-181a在骨肉瘤组织中高表达(P<0.001),但其表达水平与骨肉瘤患者的性别、年龄、肿瘤大小及肿瘤病理分期等无明显相关性(P>0.05)。MTT及transwell结果显示过表达miR-181a促进了MG-63细胞生长、迁移和侵袭,显著高于阴性对照组(P<0.05);而抑制miR-181a的表达降低了MG-63细胞生长、迁移和侵袭,显著低于阴性对照组(P<0.05)。双荧光素酶报告基因检测结果显示miR-181a可靶向结合RASSF1A基因3'-UTR,从而调控RASSF1A的表达。结论：miR-181a可特异性结合RASSF1A基因3'-UTR,下调RASSF1A基因的表达,从而促进人骨肉瘤细胞MG-63的生长和转移。     

miR-200c inhibits metastasis of breast cancer cells by targeting HMGB1

miR-200c has been shown to regulate the epithelial-mesenchymal transition （EMT） by inhibiting ZEB1 and ZEB2 expression in breast cancer cells. This study further examined the role of miR-200c in the invasion and metastasis of breast cancer that goes beyond the regulation on ZEB1 and ZEB2 expression. In this study, the bioinformatics software （miRanda） was used to predict the target gene of miR-200c and Renilla luciferase assay to verify the result. The metastatic breast cancer cells MDA-MB-231 were cultured and transfected with the miR-200c mimic or inhibitor. The expressions of miR-200c and HMGB 1 were detected by RT-PCR and Western blotting, respectively. Transwell assay and wound healing assay were employed to examine the invasive and migrating ability of transfected cells. Target prediction and Renilla luciferase analysis revealed that HMGB1 was a putative target gene of＇miR-200c. After transfection of MDA-MB-231 cells with the miR-200c mimic or inhibitor, the expression of miR-200c was significantly increased or decreased when compared with cells transfected with the miR-200c mimic NC or inhibitor NC. Moreover, the expression of HMGB1 was reversely correlated with that of miR-200c in transfected cells. Tranwell assay showed that the number of invasive cells was significantly reduced in miR-200c mimic group when compared with miR-200c inhibitor group. It was also found that the migrating ability of cells transfected with miR-200c mimics was much lower than that of cells transfected with miR-200c inhibitors. It was suggested that miR-200c can suppress the invasion and migration of breast cancer cells by regulating the expression of HMGB1. miR-200c and HMGB1 may become useful biomarkers for progression of breast cancer and targets of gene therapy.