miRNA-34a 对人胃癌 SGC-7901细胞增殖、凋亡的影响

目的：研究 microRNA-34a(mir-34a)在人胃癌细胞中的表达水平及对胃癌 SGC-7901细胞增殖、凋亡的影响。方法通过实时定量 PCR(RT-PCR)检测人正常胃黏膜上皮细胞 GES 及人胃癌细胞株 AGS、SGC-7901、MKN-45、BGC-823中 mir-34a 的表达水平。体外将表达人 mir-34a ( has-mir-34a)慢病毒感染人胃癌 SGC-7901细胞。荧光显微镜观察评估细胞感染情况,MTT 实验、流式细胞术检测感染后胃癌SGC-7901细胞的增殖、细胞周期及凋亡情况。结果胃癌细胞 AGS、SGC-7901、MKN-45、BGC-823中 mir-34a 的表达水平较正常胃黏膜上皮细胞 GES 明显降低,其中以胃癌 SGC-7901细胞降低最为明显(P <0．01)。与阴性对照组相比, mir-34a 感染组 SGC-7901细胞增殖明显减慢( P <0．01), G1/ G0期细胞比例显著增加(P <0．05),细胞凋亡率显著升高(P <0．01)。结论 mir-34a 在多种人胃癌细胞,尤其是SGC-7901细胞中呈低表达。 mir-34a 可以抑制胃癌 SGC7901细胞的增殖,诱导细胞周期停滞及细胞凋亡。     

MicroRNA-34a inhibits human brain glioma cell growth by down-regulation of notch1

The effects of microRNA-34a (miR-34a)-regulated Notch1 gene on the proliferation and apoptosis of the human glioma cell line U87 were investigated in this study. The U87 cells were divided into miR-34a mimics, negative control, mock transfection and blank control groups in terms of different treatments. In miR-34a mimics group, human U87 glioma cells were transfected with miR-34a mimics by using lipofectamine 2000. The cells transfected with nonsense microRNA were set up as negative control group. Those treated with lipofectamine 2000 only were designated to the mock tranfection group. In the blank control group, the cells were cultured routinely and no treatment was given. The expression of miR-34a and Notch1 was detected by using real-time RT-PCR. Western blotting was employed to monitor the change in Notch1 protein. Cell proliferation and apoptosis were measured by CCK-8 and flow cytometry. The results showed that the proliferative ability of U87 cells was significantly reduced and the apoptotic cells increased in miR-34a mimics group relative to control groups. The expression of miR-34a was significantly up-regulated in mimics group as compared with control groups (P<0.05). Furthermore, Notch1 protein levels were significantly decreased in miR-34a mimics group when compared with control groups (P<0.05), but the mRNA expression of Notch1 showed no significant difference among these groups. It was concluded that miR-34a may suppress the proliferation and induce apoptosis of U87 cells by decreasing the expression of target gene Notch1, suggesting that miR-34a may become a promising gene therapeutic target for brain glioma.     

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.     

胰高血糖素样肽-1对高糖诱导人脐静脉内皮细胞凋亡的影响及相关机制

目的：探讨胰高血糖素样肽-1（glucagon—like peptide-1,GLP—1）对高糖诱导人脐静脉内皮细胞huma numbilica lvein endothelial cells,HUVECs）凋亡的影响及相关机制。方法：HUVECs加入不同处理因素后分组,分别培养48h后,MTT检测细胞活力;流式细胞仪检测细胞早期凋亡率;Westernl印迹测定细胞P-Akt,p-eNOS水平;NO试剂盒检测NO浓度。结果：高糖（33mmol／L）培养48h后HUVECs细胞活力下降p〈0．05）,细胞凋亡率增加（p〈0．01）,细胞p-Akt,p-eNOS,NO水平均下降（P〈0．05）;高糖条件下加人GLP．1（3nmol／L）培养48h,与高糖组相比较,HUVECs细胞活力增加（P〈0．01）,细胞凋亡率减少（p〈O．05）,细胞p-Akt,p-eNOS,NO水平均增／JH（V〈0．05）;P13K抑制剂wortmannine（100nmol／L）可以阻断GLP-1的抗凋亡作用及其对P—Akt蛋白、p-eNOS蛋白及NO水平的影响;eNOS抑制剂L—NAME（100umol／L）仅能阻断GLP-1的抗凋亡作用及对NO水平的影响,不影响p-Akt蛋白的表达。结论：GLP．1可改善高糖诱导的HUVECs凋亡,该抗凋亡作用可能与P13K／Akt／eNOS通路的上调相关。     

Exendin-4对高糖诱导的心肌细胞氧化应激的影响

目的:探讨Exendin-4对高糖诱导的心肌细胞氧化应激的影响。方法:通过酶消化法获取乳鼠心肌细胞,在体外高糖暴露条件下,采用不同浓度的Exendin-4处理,MTT法检测细胞的活性,同时运用生化试剂盒测定上清液中丙二醛(MDA)、超氧化物歧化酶(SOD)、还原型谷胱甘肽(GSH)的水平。结果:与对照组相比,高糖环境下的心肌细胞活性明显减低(P<0.05),MDA含量明显增加(P<0.05),SOD及GSH含量明显减少(P<0.05),而给予Exendin-4预处理后,能逆转上述指标的变化,在浓度为1nmol/L和10nmol/L时具有统计学意义(P<0.05)。结论:高浓度葡萄糖通过氧化应激作用诱导心肌细胞损伤,Exendin-4通过抗氧化作用对心肌细胞起到较好的保护性作用。     

microRNA-34a在肺癌细胞凋亡中的作用

目的 探讨microRNA-34a在肺癌细胞凋亡中的作用。 方法 将A549肺癌细胞株分为3组:microRNA-34a转染组、对照组和未转染组。分析microRNA-34a在A549肺癌细胞中的表达,microRNA-34a对A549肺癌细胞生长周期、细胞增殖、细胞凋亡的影响,microRNA-34a对A549肺癌细胞Bcl-2、P53和C-MYC蛋白以及mRNA表达的影响。 结果 miRNA-34a转染组microRNA-34a的表达明显高于对照组(P<0.05)。miRNA-34a转染组G₀/G₁细胞明显高于对照组和未转染组(P<0.05)。miRNA-34a转染组48 h和96 h的增殖率明显低于对照组和未转染组(P<0.05)。miRNA-34a转染组的细胞凋亡明显高于对照组和未转染组(P<0.05)。miRNA-34a转染组的Bcl-2蛋白和C-MYC蛋白表达水平明显低于对照组(P<0.05);miRNA-34a转染组的P53蛋白表达水平明显高于对照组(P<0.05)。miRNA-34a转染组的Bcl-2 mRNA和C-MYC mRNA表达水平明显低于对照组Bcl-2 mRNA和C-MYC mRNA表达水平(P<0.05);miRNA-34a转染组的P53 mRNA表达水平明显高于对照组P53 mRNA表达水平(P<0.05)。 结论 microRNA-34a抑制A549肺癌细胞增殖,促进A549肺癌细胞的凋亡,机制可能为下调Bcl-2和C-MYC基因,上调P53基因。      

6-OHDA Induces Cycle Reentry and Apoetosis of PC12 Cells through Activation of ERK1/2 Signaling Pathway

This study investigated the effect and mechanism of cell cycle reentry induced by 6-hydrodopamine (6-OHDA) in PCI2 cells.By using neural differentiated PCI2 cells treated with 6-OHDA,the apoptosis model of dopaminergic neurons was established.Cell viability was measured by MTT.Cell apoptosis and the distribution of cell cycle were assessed by flow cytometry.Western blot was used to detect the activation of extracellular regulator kinasel/2 (ERK1/2) pathway and the phosphorylation of retinoblastoma protein (RB).Our results showed that after PC12 cells were treated wtih 6-OHDA,the viability of PC12 cells was declined in a concentration-dependent manner.Flow cytometry revealed that 6-OHDA could increase the apoptosis ratio of PC12 cells in a time-dependent manner.The percentage of cells in G0/G1 phase of cell cycle was decreased and that in S phase and G2/M phase increased.Simultaneously,ERK1/2 pathway was activated and phos- phorylated RB increased.It was concluded that 6-OHDA could induce cell cycle reentry of dopa-minergic neurons through the activation of ERK1/2 pathway and RB phosphorylation.The aberrant cell cycle reentry contributes to the apoptosis of dopaminergic neurons.     

miR-34a通过靶向调控Notch1表达影响乳腺癌细胞的增殖

目的探讨miR-34a通过靶向调控Notch1表达影响乳腺癌细胞的增殖。方法乳腺癌细胞MCF-7转染miR-34a mimics及miR-34a NC,RT-PCR法检测细胞中miR-34a表达,MTT,克隆形成实验,Hoechst染色及流式细胞术分别检测miR-34a mimics对乳腺癌MCF-7细胞活力、克隆能力、凋亡情况及细胞周期的影响;通过双荧光素酶报告基因实验,western blot及RT-PCR检测Notch1是否是miR-34a的下游靶基因。结果与miR-34a NC比较,miR-34 mimics组中miR-34a表达量上调,细胞活力降低(P0.01),细胞凋亡率显著提高(P0.01),细胞克隆数目减少(P0.01),细胞周期阻滞在G1期(P0.01),Notch1蛋白及mRNA表达量都显著降低(P0.01),同时荧光素酶报告基因实验也证实miR-34a mimics能与报告基因结合。结论 miR-34a mimics能通过负性调控Notch1表达,从而显著的抑制MCF-7乳腺癌细胞增值,并诱导细胞凋亡。     

Bcl-2抑制剂S1诱导人卵巢癌细胞凋亡及其机制的研究

目的:以人卵巢癌细胞SKOV3为研究对象,探讨Bcl-2抑制剂S1诱导人卵巢癌细胞凋亡的机制。方法:通过MTT法检测S1作用下卵巢癌细胞的生存率;S1 10μmol/L作用不同时间,流式细胞术检测细胞凋亡率;Western Blot检测凋亡相关蛋白Mcl-1的变化。结果:与对照组相比S1能明显抑制SKOV3的生存率;流式细胞术结果显示,S1引起SKOV3细胞凋亡明显升高;蛋白水平检测S1作用8 h能明显抑制SKOV3细胞Mcl-1蛋白表达。结论:S1可能通过抑制Mcl-1蛋白诱导人卵巢癌细胞凋亡。     

转录因子NF-kB在肿瘤坏死因子α介导的胰岛β细胞凋亡中的作用

目的 探讨肿瘤坏死因子(17NFα)是否可引起胰岛B细胞凋亡以及转录因子核因子kB(NF—kB)在TNFα诱导的β细胞凋亡中所起的作用。方法培养INS-1胰岛β细胞,采用DNA重组、转染和再感染技术获得可表达NF—kB的特异性抑制物：IkBα的突变体IkBα△N的INS-1／IkB△N细胞。应用DNA片段分析技术和kB—luc报告基因荧光分析技术观察NF—kB活性和β细胞的凋亡情况。结果IL—Iβ可诱导INS-1细胞的NF—kB激活,但在INS-1／IkB△N细胞则无此作用。将细胞与IL-1β(10μg/L)、TNFα(100μg/L)以及IFNγ(100000U／L)一道培养48h后显示,TFNFα与IFNγ合用可诱导INS-1细胞发生凋亡,而在INS-1／IkB△N细胞未见此现象。单用IL—Iβ或IFN-γ或IL—IB加IFNγ均未能诱导INS-1细胞凋亡。结论凋亡是TNFα导致B细胞死亡的方式之一,NF—kB在TNFα介导的β细胞凋亡中具有重要作用,抑制NF—kB激活可能保护β细胞免于TNFα诱导的凋亡。     

缺血后适应中心肌营养素1对心肌细胞的保护作用研究

目的探讨心肌营养素1（CT-1）在缺血后适应中对心肌细胞的保护作用机制及参与的信号通路。方法选择H9C2乳鼠心肌细胞株．实验分为对照组、缺氧复氧组、缺氧后适应组、缺氧后适应＋cT_1组、缺氧后适应＋CT—1＋Akt阻断剂组、缺氧后适应＋CT-1＋二甲基亚砜组,MTS法检测细胞的存活率,流式细胞仪检测细胞的凋亡率,Western—blot检测Akt蛋白表达,Q．PCR检测BadmRNA的表达。结果缺氧复氧组较对照组细胞凋亡率明显增加,存活率降低,缺氧后适应组细胞比缺氧复氧组凋亡率低,存活率增加,缺氧后适应＋CT-1组细胞比缺氧后适应组凋亡率进一步降低,存活率进一步增加．Akt磷酸化蛋白水平明显升高,BadmRNA表达下调,加入Akt阻滞剂（A6730）后,这种保护作用被抑制。结论心肌营养素1参与激活Akt信号通路协同缺氧后适应减轻缺氧复氧对心肌细胞的损伤,对心肌细胞起保护作用。     

苦参碱诱导人肺鳞癌SK-MES-1细胞凋亡作用及其可能机制

目的：探讨苦参碱（MT）诱导人肺鳞癌细胞株SK-MES-1凋亡作用及其抗肿瘤机制。方法：培养人肺鳞癌细胞株SK-MES-1,用不同浓度的MT处理SK-MES-1细胞,用MTT法检测MT对SK-MES-1细胞生长增殖的抑制作用;流式细胞术检测细胞凋亡率和细胞周期;流式细胞术检测细胞相关凋亡蛋白Bcl-2、bax、caspase-3表达。结果：MT抑制SK-MES-1细胞增殖和诱导SK-MES-1细胞的凋亡作用均呈剂量和时间依赖性。与对照组相比,苦参碱处理后的SK-MES-1细胞G0/G1期百分比明显增高,S期细胞比例下降。Bax和capase-3表达增强,Bcl-2表达下调。结论：MT在体外能抑制人肺鳞癌细胞株SK-MES-1增殖,诱导细胞凋亡,其诱导作用具有明显的量效和时效关系,可能与抑制Bcl-2活性、激活bax和capase-3有关。     

p38MAPK/eNOS信号通道在胰高血糖素样肽-1抑制AGEs诱导的人脐静脉内皮细胞凋亡中的作用

目的探讨p38MAPK信号通道在胰高血糖素样肽-1（GLP-1）拮抗糖基化终末产物（AGEs）诱导的人脐静脉内皮细胞凋亡
的作用。方法实验组分为对照组、AGEs组、GLP-1组、AGEs+GLP-1组、AGEs+抑制剂组及AGEs+GLP-1+抑制剂组,western
blot技术检测p-p38MAPK/p38MAPK、p-eNOS/eNOS蛋白表达情况,Annexin V/PI流式检测细胞凋亡率。结果与对照相比较,
单独加入AGEs或GLP-1可分别导致p-p38MAPK蛋白表达水平明显上升（P=0.001）或下降（P<0.001）;与对照组相比AGEs可
显著降低p-eNOS表达水平（P=0.007）,而予以GLP-1或p38MAPK抑制剂（SB203580）预处理后,受抑制的eNOS蛋白表达水平
再次显著升高（P=0.004）;在AGEs 组加入SB203580 或GLP-1 预处理后,AGEs诱导的细胞凋亡率均显著下降（P<0.001,P<
0.001）。结论GLP-1至少部分通过抑制p38MAPK蛋白磷酸化,上调磷酸化eNOS蛋白的表达,对人脐静脉内皮细胞起到抗凋
亡的保护作用。
     

6-OHDA induces cycle reentry and apoptosis of PC12 cells through activation of ERK1/2 signaling pathway

This study investigated the effect and mechanism of cell cycle reentry induced by 6-hydrodopamine （6-OHDA） in PC12 cells. By using neural differentiated PC12 cells treated with 6-OHDA, the apoptosis model of dopaminergic neurons was established. Cell viability was measured by MTT. Cell apoptosis and the distribution of cell cycle were assessed by flow cytometry. Western blot was used to detect the activation of extracellular regulator kinasel/2 （ERK1/2） pathway and the phosphorylation of retinoblastoma protein （RB）. Our results showed that after PC12 cells were treated wtih 6-OHDA, the viability of PC12 cells was declined in a concentration-dependent manner. Flow cytornetry revealed that 6-OHDA could increase the apoptosis ratio of PC12 cells in a time-dependent manner. The percentage of ceils in G0/G1 phase of cell cycle was decreased and that in S phase and G2/M phase increased. Simultaneously, ERK1/2 pathway was activated and phosphorylated RB increased. It was concluded that 6-OHDA could induce cell cycle reentry of dopaminergic neurons through the activation of ERK1/2 pathway and RB phosphorylation. The aberrant cell cycle reentry contributes to the apoptosis of dopaminergic neurons.     

人GLP-1(7-36)酰胺对非肥胖型糖尿病小鼠胰岛β细胞凋亡的影响

目的探讨人胰高糖素样肽1(GLP-1)对非肥胖型糖尿病(NOD)小鼠胰岛β细胞凋亡的影响。方法 GLP-1治疗组小鼠用微型渗透泵皮下持续泵入人GLP-1,对照组小鼠泵入生理盐水,4周后将其胰腺组织做HE染色、TUNEL/胰岛素双重免疫荧光染色,显微镜下观察小鼠胰岛炎的变化及胰岛β细胞的凋亡情况。结果与对照组相比,GLP-1治疗组小鼠胰岛单核细胞浸润明显减轻,胰岛炎评分明显下降(P<0.001)。在对照组小鼠胰腺组织切片中观察到较多凋亡β细胞,而在GLP-1治疗组却很少见到。GLP-1治疗组小鼠胰岛β细胞凋亡率与对照组小鼠相比明显下降(0.07±0.01%vs0.26±0.02%,P<0.001)。结论人GLP-1持续刺激NOD小鼠后,可使1型糖尿病小鼠胰岛炎减轻并抑制β细胞凋亡。     

凋亡信号调节激酶1在紫花牡荆素诱导结肠癌细胞凋亡中的作用

目的:研究紫花牡荆素诱导人结肠癌细胞凋亡作用及其作用机制。方法:体外培养人结肠癌HT-29细胞。碘化丙啶(P)I染色流式细胞术(FCM)和细胞凋亡ELISA试剂盒检测细胞凋亡。荧光探针二氯荧光素(DCFH-DA)标记FCM测定细胞内活性氧的含量。Western blot和小干扰RNA转染用于探索其分子机制。结果:紫花牡荆素以浓度依赖性的方式诱导结肠癌HT-29细胞系细胞凋亡。紫花牡荆素引起活性氧(ROS)的产生,并激活HT-29细胞的凋亡信号调节激酶1(ASK1)。N-乙酰半胱氨酸(NAC)预处理HT-29细胞有效地抑制ASK1活性,减弱紫花牡荆素处理引起的细胞凋亡。ASK1特异小干扰RNA能显著减弱紫花牡荆素诱导HT-29细胞凋亡作用。结论:紫花牡荆素通过刺激活性氧形成活化ASK1诱导结肠癌HT-29细胞凋亡。     

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。     

Pannexin1通道在顺铂诱导睾丸癌I-10细胞凋亡中的作用

目的观察pannexin1通道在顺铂诱导睾丸癌I-10细胞凋亡中的作用及其机制。方法MTT法检测细胞存活率;Annexin V/PI双染法和Hoechst 33258染色法分别检测细胞早期和晚期凋亡;化学发光法检测细胞外ATP浓度;ELISA法检测细胞内IP3 含量。结果MTT法显示pannexin1通道抑制剂CBX与顺铂合用组的细胞存活率高于单用顺铂组（P<0.01）;Annexin V/PI双染 法显示CBX与顺铂合用组的细胞早期凋亡率低于单用顺铂组（P<0.001）;Hoechst 33258染色法显示CBX与顺铂合用组的细胞 晚期凋亡率低于单用顺铂组（P<0.01）;化学发光法表明CBX与顺铂合用组的细胞外ATP浓度低于单用顺铂组（P<0.05）;ELISA 法表明CBX与顺铂合用组的细胞内IP3浓度低于单用顺铂组（P<0.05）。结论Pannexin1通道参与顺铂诱导睾丸癌I-10细胞的 凋亡,其机制可能与介导ATP/IP3信号通路有关。     

GLP-1受体激动剂Exendin4对胰岛β细胞胰岛素和IAPP分泌模式的影响

目的：探讨GLP-1受体激动剂（GLP-1RA）Exendin4作用下胰岛β细胞的胰岛素及胰淀粉样多肽（IAPP）的分泌模式。方法：观察小鼠胰岛瘤细胞系MIN6细胞在不同浓度Exendin4作用不同时间后的细胞形态的变化;利用MTT实验检测MIN6细胞在不同干预后的细胞活性的变化;采用葡萄糖刺激胰岛素分泌实验,检测MIN6细胞在不同干预后培养液上清中的胰岛素和IAPP分泌量的变化;采用荧光定量PCR（RT-PCR）检测各组MIN6细胞的胰岛素和IAPP mRNA表达水平的变化。结果：与正常对照组比较,Exendin4组的细胞数量增加,贴壁牢固,形态正常;细胞活性随Exendin4作用浓度以及作用时间的增加而显著增加,具有一定的浓度及时间依赖性;胰岛素和IAPP的分泌水平随Exendin4作用浓度以及作用时间的增加而显著增加,具有一定的浓度及时间依赖性,而IAPP/胰岛素的比值随作用浓度以及作用时间的增加而减小;胰岛素和IAPP mRNA水平均随Exendin4作用浓度以及作用时间的增加而上调,具有一定的浓度及时间依赖性,IAPP/胰岛素mRNA比值随作用浓度以及作用时间的增加而减小。结论：Exendin4作用于MIN6细胞可增加细胞数量和细胞活性,改善细胞状态,保护胰岛细胞功能;并且可引起胰岛素以及IAPP分泌水平增加,胰岛素和IAPP mRNA表达水平增加,而IAPP/胰岛素比值下降。     

MircoRNA-218下调BMI-1表达水平介导的抗骨肉瘤作用

目的初步探讨microRNA-218在人骨肉瘤中的抗肿瘤作用及其分子机制。方法利用qRT-PCR检测68例人骨肉瘤组织 和癌旁组织中miR-218 的表达水平。将miR-218 模拟物或抗miR-218 模拟物转染入人骨肉瘤Saos-2 细胞,通过CCK-8、 Annexin V-FITC和Western blotting检测转染后的细胞活性、细胞凋亡和C-PARP蛋白表达水平。利用luciferase assay筛选和识 别miR-218的作用靶点及具体作用位点,进一步通过qRT-PCR 和Western blotting检测转染miR-218模拟物或抗miR-218模拟 物后Saos-2细胞中BMI-1基因和蛋白的表达水平。结果人骨肉瘤组织中的miR-218表达水平明显低于癌旁组织。CCK-8结 果显示,与对照组相比,转染miR-218模拟物24、36和48 h后的Saos-2细胞活性显著降低,而转染抗miR-218模拟物的Saos-2细 胞活性则显著增高。同时,转染miR-218模拟物组的C-PARP的蛋白表达水平较转染抗miR-218模拟物组和对照组明显增强。 Annexin V-FITC凋亡检测结果显示,转染miR-218模拟物组的细胞凋亡数和凋亡率较对照组显著增加。此外,luciferase assay 结果显示Saos-2细胞中miR-218的特异性作用靶点为BMI-1,在miR-218过表达时BMI-1的基因和蛋白表达水平明显被抑制, 而miR-218 敲除时则显著增强;miR-218 可通过直接结合BMI-1 3’-UTR抑制BMI-1 的表达。结论miR-218 可能通过下调 BMI-1水平促进人骨肉瘤细胞Saos-2细胞凋亡,进而发挥其抗肿瘤作用。