miR-152影响NK细胞对JEG-3细胞的杀伤效应

目的:研究miR-152分子对NK细胞杀伤JEG-3细胞效应的影响。方法:在滋养细胞肿瘤细胞系JEG-3细胞中分别转染pre-miR-152(实验组),Cy3标记的pre-miRNA-control(阴性对照),空白对照(NC)为未转染的JEG-3细胞。转染48h进行NK细胞的细胞毒测定,观察各组NK细胞对JEG-3细胞的杀伤效应。结果:与对照组相比,实验组NK细胞对JEG-3细胞的平均杀伤率显著增高(P<0.05),且随着效靶比的增高,杀伤率也增大。空白对照组与阴性对照组之间的NK细胞杀伤能力无显著差异(P>0.05)。结论:miR-152可以提高NK细胞对滋养细胞的杀伤作用。     

子宫内膜癌中microRNA-125b对HER2基因3＇非翻译区的调控作用

目的：明确miR-125b在子宫内膜癌中对HER2基因3＇UTR的靶向调控作用。方法：分别构建野生型和突变型HER2基因3＇UTR荧光素酶载体;软件预测HER2基因3＇UTR靶向miRNAs;共转染miR-125b和荧光素酶载体于HEC-1B细胞中,双荧光素酶检测系统测定荧光素酶活性。结果：通过软件预测在HER2 3＇UTR第37bp位置有一个miR-125b结合位点;与转染对照miR组和突变型载体组相比,miR-125b前体能明显降低野生型载体的荧光素酶活性。结论：miR-125b能够靶向负性调控HER2基因3＇UTR活性。     

微小RNA-152对乳腺癌细胞增殖及阿霉素敏感性影响的实验研究

目的 探讨微小RNA-152（miR-152）对乳腺癌细胞阿霉素敏感性的影响及其作用机制。方法 采用实时定量PCR（QPCR）检测人乳腺上皮细胞株HBL-100、人乳腺癌MCF-7细胞及阿霉素耐药株MCF-7／ADR细胞中的miR-152水平,分别向MCF-7细胞和MCF-7／ADR细胞转染miR-152模拟物 mimics（过表达组）和阴性对照NC（阴性对照组）,以未行转染为空白对照组。采用QPCR检测转染后MCF-7细胞和MCF-7／ADR细胞中miR-152的表达情况,采用MTT法检测不同浓度阿霉素（10、50、100、200和500 ng/ml）处理后各组的增殖情况,流式细胞术检测转染后各组的凋亡率,Western blotting检测磷脂酰肌醇激酶-3催化亚基α基因（PIK3CA）的蛋白水平,双荧光素酶报告实验评价miR-152对PIK3CA的靶向调控作用。结果 QPCR实验结果 表明MCF-7细胞和MCF-7／ADR细胞中的miR-152水平均低于HBL-100细胞,且MCF-7／ADR细胞的miR-152水平均低于MCF-7细胞,差异有统计学意义（P＜0.05）;过表达组转染后的miR-152水平均高于阴性对照组和空白对照组（P＜0.05）。与其余两组比较,过表达组的存活率降低而凋亡率升高,且PIK3CA蛋白水平也降低,差异有统计学意义（P＜0.05）。miR-152可抑制野生型PIK3CA 3’ UTR报告基因载体的荧光素酶活性,而对突变型PIK3CA 3’UTR的荧光素酶活性无影响。结论 miR-152表达在乳腺癌细胞中降低,且与阿霉素耐药有关,参与乳腺癌细胞的增殖和凋亡过程,在逆转乳腺癌耐药中发挥重要作用,具有一定价值。     

miR-147靶向MDM2调控卵巢癌细胞Skov3增殖与凋亡的机制研究

目的 探讨微小RNA-147（miR-147）靶向调控鼠双微粒体2蛋白（MDM2）的表达及其对卵巢癌细胞株Skov3增殖与凋亡的影响。方法 采用Lipo2000脂质体法将miR-147 模拟物（mimics）及阴性对照（NC）转染至Skov3细胞并分为miR-147 mimics组和NC组,采用实时荧光定量PCR（QPCR）法检测转染48 h后Skov3细胞的miR-147水平以评价转染效果,分别采用MTT法及流式细胞术检测两组转染后的增殖及细胞凋亡情况,Western blotting检测两组MDM2、p53和caspase-3表达水平,采用双荧光素酶报告实验验证miR-147与靶标MDM2之间的靶向关系及结合位点。结果 QPCR检测显示,miR-147 mimics组miR-147的表达水平高于NC组,差异有统计学意义（P<0.05）,提示在Skov3细胞中过表达miR-147成功。与NC组相比,miR-147 mimics组的增殖率和MDM2水平均降低,但凋亡率及p53和caspase-3水平均升高,差异有统计学意义（P<0.05）;双荧光素酶报告实验检测发现miR-147可显著抑制野生型MDM2-3’端非翻译区（UTR）质粒转染细胞的荧光素酶活性,而对突变型MDM2-3’UTR质粒转染细胞的荧光素酶活性并无影响。结论 miR-147可靶向MDM2的表达,且过表达miR-147表达可抑制Skov3细胞的增殖并诱导凋亡,在卵巢癌防治上有一定参考价值。     

三氧化二砷联合miR-203对人白血病K562细胞的抑制作用及其机制

目的： 研究三氧化二砷（As 2O 3）联合过表达的微小RNA-203（microRNA-203,miR-203）对白血病K562细胞的抑制作用及其可能的分子机制。 方法： 将miR-203的真核表达载体pmiR-203转染K562细胞,Real-time PCR检测细胞内miR-203的表达。将K562细胞分为空白对照组、As 2O 3组、pmiR-203组、空质粒对照组、As 2O 3联合空质粒对照组和As 2O 3联合pmiR-203组,MTT法检测各组细胞增殖抑制率,流式细胞术仪检测细胞凋亡率,Western Blotting检测细胞内Bcr/abl蛋白的表达水平。构建Bcr/abl 3′UTR和Bcr/abl mut-3′UTR的双荧光素酶报告基因载体,将其与pmiR-203共转染K562细胞,通过荧光素酶活性分析判断miR-203是否与Bcr/abl基因的3′UTR结合。 结果： miR-203的真核表达载体pmiR-203转染K562细胞后,细胞内miR-203的表达水平明显增高( P <0.05)。高表达miR-203联合As 2O 3使K562细胞对As 2O 3的敏感性提高到单用As 2O 3的4.86倍,IC50 从3.4 μmol/L降低至0.7 μmol/L,两者联用表现为协同作用。As 2O 3联合pmiR-203组的细胞凋亡率显著高于As 2O 3联合空质粒对照组\[（29.97±3.19）% vs （10.77±1.71）%, P <0.05\]。过表达miR-203显著下调K562细胞内Bcr/abl蛋白的表达水平。Bcr/abl 3′UTR中带有明确的miR-203结合位点。 结论： miR-203可提高白血病K562细胞对As 2O 3的敏感性,miR-203和As 2O 3联用对K562细胞具有协同抑制作用,其作用机制可能与miR-203直接下调Bcr/abl融合基因的表达有关。     

miRNA-221对卵巢癌细胞生物学行为的影响分析

目的:探讨微小RNA-221（microRNA-221，miRNA-221)对卵巢癌细胞生物学行为的影响。方法:对人卵巢癌细胞系OVCAR3瞬时转染miR-221 mimics为实验组，转染miR-negative control mimics为阴性对照组，不进行任何转染为空白对照组，转染48 h后进行四甲基偶氮唑蓝(MTT)比色法实验、流式细胞实验、Transwell迁移实验，观察卵巢癌细胞OVCAR3生长状况。结果:实时定量PCR（real-time PCR）检测显示实验组miR-221的表达水平较阴性对照组与空白对照组均有增高(P＜0.05)。MTT检测显示，上调OVCAR3细胞内miR-221水平后，细胞增殖抑制率为（29.81±2.24）%，而阴性对照组与空白对照组分别为（2.49±0.28）%和（1.98±0.24）%，实验组与阴性对照组和空白对照组相比，细胞增殖抑制率增高，差异均有统计学意义（P＜0.05）。流式细胞术检测显示实验组OVCAR3细胞凋亡率为（30.33±2.39）%，而阴性对照组与空白对照组分别为（8.13±0.71）%和（6.89±0.58）%，实验组与阴性对照组和空白对照组相比，细胞凋亡率增高，差异均有统计学意义（P＜0.05）。Transwell迁移实验显示，转染miR-221 mimics后实验组、阴性对照组、空白对照组三组的细胞迁移能力差异无统计学意义(P＞0.05)。结论:瞬时转染miR-221 mimics的上皮性卵巢癌（EOC）细胞系，细胞增殖受到抑制而对细胞的迁移没有影响，表明miR-221可能参与了EOC细胞增殖和凋亡过程。     

miR-155在非小细胞肺癌组织和细胞中的表达及对细胞增殖、迁移、侵袭的影响

目的:探讨miR-155在非小细胞肺癌（NSCLC）中的表达及其对NSCLC细胞增殖、迁移、侵袭的影响机制。方法:通过生物信息学网站预测miR-155的可能靶基因,双荧光素酶报告基因实验进行验证;采用qRT-PCR测定NSCLC组织及细胞中miR-155和ZIC3的表达;通过LipofectamineTM2000试剂盒向A549细胞中分别转染miR-155 mimic和mimic NC,共转染miR-155 mimic+pMIR-ZIC3;Western blot检测转染miR-155 mimic对ZIC3蛋白表达的影响;MTT法、划痕实验及Transwell侵袭实验分别检测miR-155对A549细胞增殖、迁移及侵袭的影响。结果:生物信息学网站预测显示ZIC3-3' UTR与miR-155存在结合位点,双荧光素酶报告基因实验验证ZIC3是miR-155的靶基因,ZIC3表达受miR-155的负向调控。NSCLC组织及细胞中miR-155显著低表达,ZIC3显著高表达（P＜0.05）;过表达miR-155抑制了ZIC3蛋白的表达水平（P＜0.05）。转染miR-155 mimic显著抑制NSCLC细胞的增殖、迁移及侵袭能力（P＜0.01）;共转染miR-155 mimic+pMIR-ZIC3逆转了miR-155 mimic对NSCLC细胞增殖、迁移及侵袭的抑制作用（P＜0.05）。结论:NSCLC中miR-155显著低表达,其过表达可抑制NSCLC细胞的增殖、迁移及侵袭;miR-155可能通过靶向负调控ZIC3影响NSCLC细胞的生物学行为。     

miRNA-24下调S100A8蛋白表达能够抑制人喉鳞癌Hep2细胞侵袭

目的：探讨microRNA-24（miRNA-24）对喉鳞状细胞癌（laryngeal squamous carcinoma,LSCC）Hep2细胞侵袭影响的分子机制。方法：应用miRanda和RNA22靶基因预测软件预测miR-24的靶基因及其结合位点,根据预测结果通过转染miR-24前体上调其在Hep2细胞中的表达,应用荧光定量PCR和Western blot分别检测miR-24过表达对S100钙结合蛋白A8（S100 calcium binding protein A8,S100A8）mRNA和蛋白表达变化的影响。S100A8抗体阻断方法,检测转染miR-24前体后Hep2细胞侵袭能力的变化。结果：S100A83＇非翻译区（3＇-untranslation region,3＇UTR）含有一个miR-24结合位点,而且该位点与大鼠的同源性高达95%;miR-24基因转染的Hep2细胞中miR-24的表达显著升高,S100 A8蛋白的表达显著降低,（P均〈0.05）,而S100A8 mRNA表达变化未见显著性差异,（P〉0.05）。与未阻断组相比,miR-24前体转染能明显降低阻断S100A8组的Hep2细胞侵袭能力,（P〈0.05）。结论：LSCC Hep2细胞中,miR-24可结合到S100A8基因的3＇UTR,在转录后水平上负性调控S100A8基因的表达,从而抑制Hep2细胞侵袭。     

微小RNA-373靶向调控LATS2的表达及其对肝癌细胞HepG2增殖与凋亡的影响

目的 探讨微小RNA-373（miR-373）靶向调控大肿瘤抑制因子2（LATS2）的表达及其对肝癌细胞HepG2增殖与凋亡的影响。方法 采用实时荧光定量PCR（QPCR）法检测HepG2细胞及正常肝细胞LO2中miR-373的表达水平,采用Lipofectamine脂质体法将miR-373抑制剂及阴性对照转染至HepG2细胞并分为抑制剂组和对照组,采用QPCR法检测两组的miR-373水平以评价转染效果,MTT法和流式细胞术分别检测各组细胞的增殖及凋亡情况,Western blotting检测各组凋亡相关基因（Bax和caspase-3）及LATS2的表达情况,采用双荧光素酶报告实验验证miR-373与LATS2间的靶标关系。结果 与LO2细胞相比,HepG2细胞中miR-373的表达水平升高,差异有统计学意义（P＜0.05）;转染后抑制剂组的miR-373水平低于对照组（P＜0.05）,提示抑制HepG2细胞miR 373表达成功;与对照组比较,抑制组的细胞增殖率降低,凋亡率及Bax、caspase-3和LATS2蛋白水平均升高,差异有统计学意义（P＜0.05）;双荧光素酶报告基因实验表明miR-373可显著抑制野生型LATS2-3’UTR质粒转染细胞的荧光素酶活性,而对突变型LATS2-3’UTR质粒转染细胞的荧光素酶活性并无影响。结论 miR-373可靶向调控LATS2的表达,且抑制miR-373表达可抑制HepG2细胞增殖并诱导凋亡,为肝癌的靶向治疗提供一定参考。     

微小RNA-199b-3p靶向调控SOX6的表达及其对结肠癌细胞SW620增殖和凋亡的影响

目的 探讨微小RNA-199b-3p（miR-199b-3p）靶向调控SOX6的表达及其对结肠癌细胞SW620增殖及凋亡的影响。方法 采用Lipofectamine脂质体法将miR-199b-3p抑制剂及阴性对照（NC）转染至SW620细胞并分为抑制剂组和NC组,同时以未转染的SW620细胞作对照。采用实时荧光定量PCR（QPCR）法检测3组miR-199b-3p的表达以评价转染效果,MTT法和Annexin Ⅴ-FITC／PI流式细胞术检测转染后的增殖活性及凋亡率,QPCR和Western blotting检测各组凋亡相关基因（Bax和caspase-3）及SOX6的mRNA和蛋白水平,构建含有野生型及突变型SOX6-3’UTR的荧光报告基因质粒并采用双荧光素酶报告实验验证miR-199b-3p对SOX6的靶向调控作用。结果 QPCR检测显示,转染48 h后抑制剂组的miR-199b-3p的表达水平为0.526±0.034,低于未转染组的1.009±0.064和NC组的0.960±0.057,差异有统计学意义（P＜0.05）;与其余两组相比,抑制剂组转染24、48、72 h后的SW620细胞的增殖活性均降低（P＜0.05）;抑制剂组的凋亡率为（37.533±1.459）％,高于未转染组的（6.101±0.663）％和NC组的（8.753±1.061）％,差异均有统计学意义（P＜0.05）;抑制剂组SW620细胞的SOX6、Bax、caspase-3 mRNA和蛋白表达水平均高于未转染组和NC组,差异均有统计学意义（P＜0.05）。双荧光素酶报告基因实验表明 miR-199b-3p可显著抑制野生型 SOX6-3’UTR的荧光荧光素酶活性,而对突变型质粒转染细胞的荧光素酶活性并无影响。结论miR-199b-3p可靶向调控SOX6的表达,且下调miR-199b-3p表达可抑制SW620细胞的增殖并诱导凋亡,为结肠癌的治疗提供潜在的分子治疗靶点。     

Downregulations of B‐cell lymphoma 2 and myeloid cell leukemia sequence 1 by microRNA 153 induce apoptosis in a glioblastoma cell line DBTRG‐05MG

MicroRNA‐153 (miR‐153) is a brain‐specific miRNA that is expressed at a significantly lower level in glioblastoma (GBM) relative to non‐neoplastic brain tissue. Although the expression pattern of miR‐153 has been extensively established, its target genes and cellular mechanism remain undefined. To investigate into the potential function of miR‐153 in glioblastmas, we transfected a GBM cell line DBTRG‐05MG with synthetic miR‐153 oligos and observed decreased cell proliferation and increased apoptosis. Bioinformatics analysis revealed that anti‐apoptosis family member B‐cell lymphoma 2 (Bcl‐2) and myeloid cell leukemia sequence 1 (Mcl‐1) are potential targets of miR‐153. Indeed, Western blot analysis indicated that miR‐153 downregulated both Bcl‐2 and Mcl‐1 at the protein levels. Single strand miR‐153 inhibitor, which forms complementary base‐pair with endogenous miR‐153, efficiently blocked the apoptosis and target protein degradation induced by overexpression of miR‐153. By luciferase reporter assays, we further showed that miR‐153 inhibited Bcl‐2 and Mcl‐1 expressions by directly targeting the 3′UTR regions of their respective mRNAs.     

Evaluation of genetic variants in microRNA biosynthesis genes and risk of breast cancer in Chinese women

MicroRNAs (miRNA) are a class of small, noncoding RNA molecules involved in a diversity of cellular functions. Single nucleotide polymorphisms (SNPs) in miRNA biosynthesis genes may affect the biogenesis of miRNAs and consequently affect the miRNAs regulation. In this study, we systematically selected 24 functional SNPs located in eight key biosynthesis genes of miRNA (DROSHA, DGCR8, RAN, DICER, AGO2, GEMIN3, GEMIN4 and HIWI) and investigated the association between these SNPs and the risk of breast cancer in a Chinese population. All 24 SNPs were firstly genotyped in stage 1 (878 cases and 900 controls) and three promising SNPs (DROSHA rs2291109, RAN rs7301722 and DGCR8 rs417309) were selected for further validation in stage 2 (914 cases and 967 controls). We found that only one SNP (rs417309) located in the 3′‐UTR of DGCR8 was consistently associated with an increased breast cancer risk in two stages with a combined odds ratio (OR) of 1.50 [95% confidence interval (CI) = 1.16–1.93]. Based on the bioinformatics prediction, rs417309 is located at the binding sites of miR‐106b and miR‐579 in the 3′‐UTR of DGCR8. To evaluate whether rs417309 variant affects the binding capacity of miRNAs, we cotransfected luciferase reporter plasmids of DGCR8 3′‐UTR and miR‐106b/miR‐579 in three cell lines. Luciferase activity assay showed a higher expression level with rs417309 A allele compared with G allele in MCF‐7 cell lines (p = 3.31 × 10^–7, 9.29 × 10^–7 for miR‐106b and miR‐579, respectively). Our findings suggested that DGCR8 rs417309 G > A might affect breast cancer risk through the interruption of miRNA binding.     

DNA修复基因RAD52 miRNA靶序列单核苷酸多态性与肝细胞癌遗传易感性研究

目的 探讨DNA修复基因RAD52 3'非翻译区（3'- untranslated region,3'-UTR）miRNA靶序列单核苷酸多态性（single nucleotide polymorphism,SNP）与广西地区人群肝细胞癌（hepatocellular carcinoma,HCC）遗传易感性的关系。方法 采用病例- 对照研究,对1 002例确诊的HCC新发病例和1 013例非肿瘤患者RAD52基因3'-UTR区域miRNA靶序列SNPs （rs1051669、rs1051672、rs7301931和rs7310449）进行基因分型,并分析其基因型频率分布及其与HCC遗传易感性的关系。结果 RAD52基因各SNP基因型在病例组和对照组中的分布频率差异均无统计学意义（P>0.05）。调整年龄、性别、吸烟、饮酒和HBV感染等因素后,未发现各SNP与HCC易感性有关联;分层分析发现,在女性人群中,与携带rs1051669 C等位基因相比,TT基因型可显著降低个体罹患HCC的风险（TT vs CT/CC：OR=0.03,95%CI：0.00~0.62,P=0.03）;与携带rs1051672 G等位基因相比,AA基因型可显著降低个体罹患HCC的风险（AA vs GA/GG：OR=0.03,95%CI：0.01~0.88,P=0.04）。结论 RAD52基因3'- UTR区域miRNA靶序列SNPs rs1051669、rs1051672位点可能与广西地区女性人群HCC易感性有关。     

Anti‐miR‐21 oligonucleotide sensitizes leukemic K562 cells to arsenic trioxide by inducing apoptosis

Arsenic trioxide (ATO), an ancient traditional Chinese medicine, has been successfully used as a therapeutic agent for leukemia. Drug resistance and toxicity are major concerns with the treatment. MicroRNAs (miRNAs) are endogenous small non‐coding RNA molecules that might modulate cellular sensitivity to anticancer drugs. miRNA‐21 (miR‐21) is one of the most prominent miRNAs involved in various aspects of human cancers. However, miR‐21 has been rarely characterized in chronic myelogenous leukemia (CML). Here, we used a specific anti‐miR‐21 oligonucleotide (AMO‐miR‐21) to sensitize K562 cells to ATO by degradation of miR‐21. The results showed that both AMO‐miR‐21 and ATO caused growth inhibition, apoptosis, and G1‐phase arrest in K562 cells. Meanwhile, AMO‐miR‐21 significantly promoted ATO‐mediated growth inhibition and apotosis without affecting the G1 phase. Apoptotic cells were confirmed morphologically with Giemsa’s staining. Furthermore, dual‐luciferase reporter vector, containing two tandem miR‐21 binding sites from PDCD4 3′UTR, validated that PDCD4 was directly regulated by miR‐21. Therefore, AMO‐miR‐21 sensitized leukemic K562 cells to ATO by inducing apoptosis partially due to its up‐regulation of PDCD4 protein level. The combination of ATO and AMO‐miR‐21 present therapeutic potential for CML. (Cancer Sci 2010; 101: 948–954)     

子宫内膜癌中microRNA-125b对HER2基因3' 非翻译区的调控作用

目的:明确miR-125b在子宫内膜癌中对HER2基因3'UTR的靶向调控作用.方法:分别构建野生型和突变型HER2基因 3'UTR荧光素酶载体;软件预测HER2基因 3'UTR靶向miRNAs;共转染miR-125b和荧光素酶载体于HEC-1B细胞中,双荧光素酶检测系统测定荧光素酶活性.结果:通过软件预测在HER2 3'UTR第37bp位置有一个miR-125b结合位点;与转染对照miR组和突变型载体组相比,miR-125b前体能明显降低野生型载体的荧光素酶活性.结论:miR-125b能够靶向负性调控HER2基因 3'UTR活性.     

MicroRNA-200a suppresses the Wnt/β-catenin signaling pathway by interacting with β-catenin

The Wnt/β-catenin signaling pathway is crucial for human organ development and is involved in tumor progression of many cancers. Accumulating evidence suggests that the expression of β-catenin is, in part, regulated by specific microRNAs (miRNAs). The purpose of this study was to determine the expression of a recently identified epithelial to mesenchymal transition (EMT)-associated tumor suppressor microRNA (miR)-200a, in cancer cells. We also aimed to identify specific miR-200a target genes and to investigate the antitumor effects of miR-200a on the Wnt/β-catenin signaling pathway. We employed TOP/FOP flash luciferase assays to identify the effect of miR-200a on the Wnt/β-catenin pathway and we confirmed our observations using fluorescence microscopy. To determine target genes of miR-200a, a 3' untranslated region (3' UTR) luciferase assay was performed. Cell viability, invasion and wound healing assays were carried out for functional analysis after miRNA transfection. We further investigated the role of miR-200a in EMT by Western blot analysis. We found fluctuation in the expression of miR-200a that was accompanied by changes in the expression of members of the Wnt/β-catenin signaling pathway. We also determined that miR-200a can directly interact with the 3' UTR of CTNNB1 (the gene that encodes β-catenin) to suppress Wnt/β-catenin signaling. MiR-200a could also influence the biological activities of SGC790 and U251 cells. Our results demonstrate that miR-200a is a new tumor suppressor that can regulate the activity of the Wnt/β-catenin signaling pathway via two mechanisms. MiR-200a is a candidate target for tumor treatment via its regulation of the Wnt/β-catenin signaling pathway.