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1.
目的:寻找一种或多种能预测人类表皮生长因子受体2(Her-2)阳性乳腺癌患者是否发生淋巴结转移及其预后的分子标志物。创新点:本研究发现,miR-455与Her-2阳性乳腺癌转移相关,可能是一个预测Her-2阳性乳腺癌患者淋巴结转移和预后的分子标志物。miR-455可以通过与长链非编码RNA人肺腺癌转移相关转录本1(MALAT1)的相互作用,在乳腺癌的淋巴结转移过程中发挥重要功能。方法:通过下载肿瘤基因组图谱(TCGA)数据库中与乳腺癌相关的微小RNA(miRNA)测序数据,筛选与乳腺癌淋巴结转移相关的miRNA,进一步分析这些miRNA与乳腺癌患者预后的相关性。同时,用实时荧光定量聚合酶链反应(qRT-PCR)方法检测这些miRNA在不同程度淋巴结转移的Her-2阳性乳腺癌患者组织中的表达水平,及其与预后的相关性。通过细胞学实验研究过表达miR-455对Her-2阳性乳腺癌细胞系MDAMB-453增殖和侵袭能力的影响,并用qRT-PCR检测过表达miR-455对MALAT1表达的影响。结论:miR-455可能是Her-2阳性乳腺癌患者淋巴结转移和预后的潜在预测因子。  相似文献   

2.
目的:探索16个保守microRNA在雷蒙德氏棉中的表达情况。创新点:首次研究了microRNA在雷蒙德氏棉四个组织的表达情况。方法:设计16个microRNA的引物,并提取雷蒙德氏棉四个不同组织的RNA进行实时荧光定量聚合酶链式反应(q RT-PCR)。结论:在不同的组织中,这些micro RNA的表达水平差异很大。包括miR-159、miR-162、miR-164、miR-172、miR-390、miR-395、miR-397和miR-398在内的8个micro RNA在花蕾中表达含量非常高,而另外一些microRNA,例如miR-166和miR-160,在四个不同组织中都有很高的表达量。  相似文献   

3.
目的:探讨荧光定量检测在小儿患者巨细胞病毒(HCMV)感染中的诊断价值.方法:对102例小儿患者,取尿液用荧光定量PCR(FQ-PCR)技术检测.结果:102例标本中28例阳性,阳性率为27.5%.结论:荧光定量PCR检测方法具有快速、灵敏、特异等优点,在HCMV感染的早期诊断、治疗方案选择以及疗效观察方面具有广泛的应用前景.  相似文献   

4.
目的:探究新发现的两个miRNA对家蚕丝素轻链基因BmFib-L的调控作用。创新点:在家蚕后部丝腺中发现两个新的miRNA,并首次证明它们对家蚕丝素蛋白轻链基因BmFib-L有负调控作用。方法:本实验通过生物信息学分析,从家蚕后部丝腺miRNA高通量测序获得的新miRNA中,筛选出两个可能对家蚕丝素蛋白轻链基因BmFib-L有调控作用的miRNA,即bmo-miR-0001和bmo-miR-0015。设计茎环引物,采用反转录聚合酶链反应(RT-PCR)方法对家蚕5龄3 d头部、表皮、脂肪体、马氏管、精巢/卵巢、丝腺(前、中、后)、气管、中肠和血淋巴细胞等12个不同组织的bmo-miR-0001和bmo-miR-00015进行半定量表达分析。并采用双荧光报告基因检测系统进一步在细胞水平上验证bmo-miR-0001和bmo-miR-0015对BmFib-L表达的调控作用。结论:本实验中RT-PCR结果显示,这两个新miRNA在家蚕后部丝腺中表达量最高(图4)。双荧光报告基因检测结果显示,报告基因荧光素酶活性明显低于阳性对照组(图7),转染bmo-miR-0001和bmo-miR-0015表达载体的细胞,报告基因和荧光素酶活性分别只及对照组60%和69%。t检验分析结果显示两个实验组与对照组之间差异都达到显著水平(P0.05)。由此可见,bmo-miR-0001和bmo-miR-0015在体外对BmFib-L的表达具有显著的抑制作用。  相似文献   

5.
目的：探索16个保守 microRNA在雷蒙德氏棉中的表达情况。
　　创新点：首次研究了microRNA在雷蒙德氏棉四个组织的表达情况。
　　方法：设计16个 microRNA的引物,并提取雷蒙德氏棉四个不同组织的 RNA进行实时荧光定量聚合酶链式反应（qRT-PCR）。
　　结论：在不同的组织中,这些microRNA的表达水平差异很大。包括 miR-159、miR-162、miR-164、miR-172、miR-390、miR-395、miR-397和miR-398在内的8个 microRNA 在花蕾中表达含量非常高,而另外一些 microRNA,例如 miR-166和miR-160,在四个不同组织中都有很高的表达量。  相似文献   

6.
目的:构建microRNA的表达载体,再转染生物体细胞观察该microRNA的转录或表达情况,以获知它的作用机理及对生物体的影响。方法:以microRNA-21(简化为miR-21)为例说明构建表达载体的方法。根据microRNA的成熟序列以及附近约200多碱基共约470个碱基序列,设计PCR引物,PCR扩增,PCR产物和pcDNA3.1(+)质粒双酶切后,用T4连接酶进行连接反应,并转化入感受态细胞,筛选后对重组质粒进行双酶切、琼脂糖凝胶电泳鉴定及测序分析,并将其转染Hela细胞,经RT-PCR实验检测其表达情况。结果:pcDNA3.1(+)/miR-21过表达载体转染细胞后使得miR-21在细胞中过表达。结论:成功构建了miR-21的真核表达载体,为进一步研究miR-21功能及作用机制奠定实验基础。  相似文献   

7.
目的:建立快速、灵敏、特异的基因2型鹅星状病毒(Goose astrovirus 2,GoAstV-2)检测方法。方法:以GoAstV-2 ORF2基因为靶标,设计特异性检测引物并构建含目标基因的重组质粒作为阳性质粒标准品,以其为模板优化建立一种EvaGreen饱和染料荧光定量一步法RT-PCR检测方法。结果:所建立方法采用dUTP/UDG酶防污染体系,其标准曲线在2.58×101～2.58×107 copies/μL质粒模板量呈现良好的线性关系,斜率为-3.413,相关系数(R2)为0.995,熔解温度TM为(85.5±0.5)℃;该方法对质粒标准品检测灵敏度下限为25.8 copies/μL;该方法特异性检测GoAstV-2,而新城疫病毒(NDV)、H5型禽流感病毒(AIV-H5)、禽呼肠孤病毒(ARV)等11种常见禽传染病病原检测结果均为阴性。重复性试验显示,组内和组间变异系数均小于2%,表明其具有良好的重复性。GoAstV-2感染病死鹅组织定量检测显示,心脏、肝脏、脾脏、肺脏、肾脏、腺胃、胰...  相似文献   

8.
目的:研究microRNA-638(miR-638)在神经胶质瘤U251细胞中的表达丰度,以及miR-638的表达对神经胶质瘤U251细胞增殖和迁移能力的影响,从而探讨miR-638在U251细胞中促进胶质瘤发生发展的分子机制.方法:实时荧光定量聚合酶链反应(RT-PCR)检测人正常星形胶质细胞系(NHA)与胶质瘤U251细胞株中miR-638的表达水平;U251细胞转染miR-638模拟物后,MTT实验以及细胞划痕实验检测miR-638的表达对U251细胞的增殖以及迁移作用的影响.结果:与正常人脑星形胶质细胞相比,胶质瘤U251细胞株中miR-638的表达上调(P0.01);miR-638的表达能促进U251细胞的迁移能力,但是不影响细胞增殖能力(P0.05).结论:miR-638在U251神经胶质瘤细胞中高表达,对胶质瘤细胞迁移有促进作用,miR-638可能具有促进胶质瘤U251细胞发生发展的作用.  相似文献   

9.
研究目的:研究低氧训练对肥胖大鼠肝脏microRNA表达的影响及对脂代谢的调节。创新要点:通过肝脏microRNA的表达以及脂代谢的变化,揭示microRNA调节低氧训练肥胖大鼠脂代谢的相关机制。研究方法:二十只高脂饮食致肥胖大鼠进入正式实验,分为常氧安静组和低氧训练组,观察4周后肥胖大鼠形态指标(图1)以及血脂的变化(图2),microRNA微阵列芯片筛选低氧训练肥胖大鼠肝脏中722个成熟miRNA表达的差异(表2),利用实时荧光定量聚合酶链式反应(PCR)检测大鼠肝脏微小RNA-378b(miR-378b)和过氧化物酶体增殖物激活受体α(PPARα)、脂肪酸合成酶(FAS)、肉碱棕榈酰转移酶1A(CPT1A)的mRNA表达水平(图3),酶联免疫吸附测定(ELISA)法检测PPARα、FAS、CPT1A的蛋白水平(图4)。重要结论:低氧训练通过降低肥胖大鼠肝脏miR-378b的表达水平,增加大鼠对高脂饮食诱导肥胖的抵抗能力;通过降低肝脏CPT1A蛋白表达水平,增加FAS/CPT1A蛋白表达比例降低肥胖大鼠肝脏脂肪酸的氧化能力。  相似文献   

10.
为了快速检测出实验动物临床样品中的金黄色葡萄球菌（SA），建立了一种普通PCR方法。同时合成3对引物，用金黄色葡萄球菌的阳性核酸DNA做模板，进行引物扩增，筛选出一对能扩增出270 bp单一目的片段的引物。逐一对该引物灵敏度、重复性和特异性进行了测试。实验结果显示，该方法具有高度的特异性，除了识别金黄色葡萄球菌基因组外，对小鼠其他常见病原菌均不发生交叉反应，具有优良的敏感性和稳定性。两个不同操作人员，在两个不同时间段，利用两台不同品牌的PCR仪器，用金黄色葡萄球菌阳性样品进行测试，结果显示此方法再现性良好。用该方法检测待测样本，效果也良好。  相似文献   

11.
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12.
提取人乳腺癌细胞（MCF7）基因组DNA,应用PCR扩增miR-34a启动子序列,将其克隆连接到荧光素酶报告质粒p GL3-Basic中;瞬时转染人肾上皮细胞（293T）,检测荧光素酶活性。成功构建了p GL3-miR34a-promoter报告基因载体并对其测序验证,结果表明启动子序列正确,载体具有较高的启动子活性。  相似文献   

13.
《学习科学杂志》2013,22(2):153-199
We analyze the types of information that human learners rely on in the acquisition of predictive and explanatory knowledge. We present OCCAM, a computational model of this learning task that integrates three learning methods: similarity-based learning (SBL), explanation-based learning (EBL), and theory-driven learning (TDL). We focus on the strengths and weaknesses of each learning method and describe how they can be integrated in a complementary fashion. The goal of this integration is to provide a learning architecture that accounts for the effects of prior knowledge on human learning. The integration helps to explain how a learner can learn rapidly when new experiences are consistent with prior knowledge while still retaining the ability to learn in novel domains (although more slowly). In addition, we present experimental evidence that an integrated model converges on accurate concepts more rapidly than either method applied individually. OCCAM is unique among learning models in that it can make use of data-intensive learning methods to acquire the knowledge needed for knowledge-intensive learning.  相似文献   

14.
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15.
Computational prediction of microRNA genes in silkworm genome   总被引：3，自引：0，他引：3  
MicroRNAs （miRNAs） constitute a novel, extensive class of small RNAs （-21 nucleotides）, and play important gene-regulation roles during growth and development in various organisms. Here we conducted a homology search to identify homologs of previously validated miRNAs from silkworm genome. We identified 24 potential miRNA genes, and gave each of them a name according to the common criteria. Interestingly, we found that a great number of newly identified miRNAs were conserved in silkworm and Drosophila, and family alignment revealed that miRNA families might possess single nucleotide polymorphisms, miRNA gene clusters and possible functions of complement miRNA pairs are discussed.  相似文献   

16.
To investigate the effects of hypoxic exercise training on microRNA (miRNA) expression and the role of miRNA expression in regulating lipid metabolism, 20 dietary-induced obese SD rats were divided into a normoxic sedentary group (N, n=10) and a hypoxic exercise training group (H, n=10). After four weeks, measurements were taken of body weight, body length, fat mass, serum lipid concentration, miRNAs differentially expressed in rat liver, and gene and protein expression levels of peroxisome proliferator activated receptor α (PPARα), fatty acid synthetase (FAS), and carnitine palmitoyl transferase 1A (CPT1A) in rat liver. Body weight, Lee’s index, fat mass, fat/weight ratio, and serum levels of total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C) were all significantly lower in the H group than in the N group (P<0.01). Six miRNAs expressed significantly differently in the liver (P<0.05). Specifically, expression levels of miR-378b were significantly lower in the H group than in the N group (P<0.05). Compared with the normoxic sedentary group, hypoxic exercise training resulted in a lower ratio of FAS mRNA to CPT1A mRNA (P<0.05), as well as lower CPT1A protein levels (P<0.01), while a higher ratio of FAS to CPT1A protein levels (P<0.01) was observed. In conclusion, hypoxic training may elevate the resistance of high fat diet induced obesity in rats by reducing the expression of miR-378b, and decrease the fatty acid mitochondrial oxidation in obese rat livers by decreasing the protein expression of CPT1A and increasing the protein expression ratio of FAS/CPT1A.  相似文献   

17.
课程改革是一种探索,但不是拓荒。我们探究实施项目教学法时的必改之处与可不改之处,目的是充分利用现有的一切人力、物力资源,一方面发挥在长期教学实践中积累的宝贵经验,另一方面进行有针对性的弥补和拓展。  相似文献   

18.
对于复杂人脸模式、脸部特征的提取,是人脸自动识别技术的关键,本文对固定背景下人脸图像特征的定位和提取算法进行了分析.文中首先对彩色图像背景进行分割,得到二值化图像;然后采用边界搜索方法确定人脸外接矩形;最后在色度空间中,结合SUSAN角点检测方法,实现人眼、嘴角定位,完成了人脸图像特征的提取和识别.实验证明,该算法在降低运算区域的同时,降低了运算复杂度和其他干扰因素,并且在速度、效率、准确性方面均有良好的性能.  相似文献   

19.

Objective

Hepatocellular carcinoma (HCC) is still one of the most common death-related malignancies worldwide. Because the way onset and progression are hidden most, HCC diagnoses are made at an advanced stage, when they are unsuitable for surgical resection. MicroRNAs are a class of small non-coding RNAs, participating in many aspects of cancers. In this study, we tried to establish the role of microRNA-718 (miR-718) in the malignant phenotype of HCC cells and its possible role in HCC diagnosis.

Methods

Here we first used a methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay, Transwell migration and invasion assays, and colony formation assay to evaluate the impact of miR-718 on the malignant phenotypes of HCC cells. Then, we used bioinformatic methods to predict the target gene of miR-718 and used green fluorescence protein (GFP) reporter assay, Western blot, and quantitative real-time polymerase chain reaction (qRT-PCR) to validate the regulation relationship. Finally, we determined the role of the target gene in the HCC phenotype.

Results

We found that the expression of miR-718 was significantly reduced in various HCC cell lines and HCC tissues. Re-expression of miR-718 significantly reduced the cellular viability and colony formation ability as well as inhibited the migration and invasion abilities of HCC cell lines. Early growth response protein 3 (EGR3) is a direct target of miR-718 and is negatively regulated by miR-718. EGR3 could increase the viability and proliferation of HCC cells, and promot the migration and invasion of HCC cells.

Conclusions

miR-718 acts as a tumor suppressive microRNA in HCC via regulating the expression of EGR3, which may provide a new diagnostic marker and treatment target for HCC.
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20.
RNA interference (RNAi) is considered as a potential modality for clinical treatment and anti-virus animal breeding. Here, we investigate the feasibility of inhibiting classical swine fever virus (CSFV) replication by short hairpin RNA (shRNA) in vitro and in vivo. We generate four different shRNA-positive clonal cells and two types of shRNA-transgenic pigs. CSFV could be effectively inhibited in shRNA-positive clonal cells and tail tip fibroblasts of shRNA-transgenic pigs. Unexpectedly, an early lethality due to shRNA is observed in these shRNA-transgenic pigs. With further research on shRNA-positive clonal cells and transgenic pigs, we report a great induction of interferon (IFN)-responsive genes in shRNA-positive clonal cells, altered levels of endogenous microRNAs (miRNA), and their processing enzymes in shRNA-positive cells. What is more, abnormal expressions of miRNAs and their processing enzymes are also observed in the livers of shRNA-transgenic pigs, indicating saturation of miRNA/shRNA pathways induced by shRNA. In addition, we investigate the effects of shRNAs on the development of somatic cell nuclear transfer (SCNT) embryos. These results show that shRNA causes adverse effects in vitro and in vivo and shRNA-induced disruption of the endogenous miRNA pathway may lead to the early lethality of shRNA-transgenic pigs. We firstly report abnormalities of the miRNA pathway in shRNA-transgenic animals, which may explain the early lethality of shRNA-transgenic pigs and has important implications for shRNA-transgenic animal preparation.  相似文献   

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