NGAL基因在原发性肝癌中的表达及其功能分析

NGAL基因是Lipocalin家族成员,与MMP9的功能密切相关,在乳腺癌、食管癌等多种恶性肿瘤中异常表达,为了研究其在原发性肝癌中的表达及功能,通过荧光实时定量PCR法检测了NGAL基因在23对肝癌组织标本中的表达情况.结果显示：在12例肝癌组织中NGAL显著上调表达,占总样本数的52.17%（P〈0.05）,提示了NGAL基因的表达水平可能与肝癌的发生发展过程有关.通过构建绿色荧光蛋白融合表达载体,用脂质体法转化肝癌细胞株SMMC-7721进行瞬时表达.细胞周期实验显示NGAL的表达可促使SMCC-7721细胞从G1期向S期转化,转化NGAL的细胞中S期细胞显著增多（P〈0.05）,提示其可能具有促进肝癌细胞生长的功能;细胞凋亡实验发现NGAL的表达可显著抑制低血清诱导下的细胞凋亡率（P〈0.05）,提示其可能参与抑制肝癌细胞的凋亡.     

茶氯香酰胺脂质体对人肝癌细胞生长和迁移的抑制作用

以茶氯香酰胺脂质体(TClC-L)为研究对象,研究其对人肝癌细胞(SMMC7721)生长和迁移的影响,并且探索其作用的分子机制,为研发抗肝癌新药提供科学依据.应用MTT法检测TClC-L对SMMC7721细胞生长的影响;应用划痕法和细胞流式分别检测TClC-L对SMMC7721细胞迁移和死亡的影响;应用Hoechst 33258染色检测SMMC7721细胞凋亡形态学变化;应用Western blotting技术检测TClC-L对SMMC7721细胞生长、凋亡和迁移密切相关蛋白表达的影响和其可能作用的分子机制.结果显示,TClC-L对SMMC7721细胞生长有显著的抑制作用,显示出剂量和时间的依赖性关系; TClC-L能够显著地降低SMMC7721细胞的迁移能力,促进其凋亡; TClC-L显著上调抑制肝癌细胞生长和诱导癌细胞凋亡的相关蛋白因子Bax、Caspase-3、PARP和迁移抑制因子E-cadherin蛋白的表达水平,下调促进细胞生长和迁移以及抗凋亡的相关蛋白因子Bcl-2、HGF、cMet、NF-κB、MMP9、VEGFR2、c-Myc蛋白的表达水平. TClC-L抑制人肝癌细胞SMMC7721的生长和迁移作用的分子机制涉及到HGF/c-Met/VEGFR-NF-κB信号通路.     

PEI介导PKC-α反义核酸对肝癌SMMC-7721细胞的增殖抑制作用

目的:研究聚乙烯亚胺(PEI)-PKC-α反义脱氧核寡酸(ASODN)对人肝癌SMMC-7721细胞的增殖抑制作用.方法:RT-PCR检测肝癌SMMC-7721细胞、HepG2细胞PKC-α mRNA表达的差异,细胞增殖抑制实验检测PEI和ASODN混合的最佳质量比,WST法和克隆形成抑制实验检测细胞增殖抑制作用,免疫荧光检测PKC-α的表达水平.结果:SSMC-7721细胞PKC-α mRNA表达相对较高,PEI和ASODN的质量比为0.75/1时是PEI转染反义核酸的合适比例,对SMMC-7721细胞具有明显的增殖克隆抑制作用,且呈剂量-效应关系;ASODN和PEI-ASODN对SMMC-7721的IC50分别为16.6 μmol/L和0.58 μmol/L;PEI-ASODN能够有效抑制PKC-α蛋白的生物合成.结论:PEI-ASODN能显著抑制SMMC-7721细胞增殖和克隆形成,下调PKC-α蛋白的表达.     

文蛤抗癌多肽抑制肝癌细胞SMMC-7721差异蛋白质组分析

为了研究文蛤抗癌多肽对肝癌细胞抑制作用的蛋白表达差异,寻找并鉴定差异蛋白质,探讨多肽抑制肝癌细胞的作用机理,本文通过双向电泳、考马斯亮蓝染色、Melanie 4双向软件分析、质谱技术(MALDI-TOF-MS)和数据库检索分析多肽作用SMMC-7721后的差异蛋白质.利用差异蛋白质组方法分析了抗癌多肽对肝癌细胞SMMC-7721抑制后的蛋白变化,找到差异点并进行了质谱鉴定(MALDI-TOF-MS).结果表明,通过对差异蛋白功能的分析,推测抗癌多肽可能引起了肝癌细胞的凋亡,为进一步的抗癌多肽抑制肝癌细胞作用的研究提供了理论基础.     

可溶性人TRAIL蛋白诱导肝癌细胞的凋亡

为研究可溶性人TRAIL蛋白（sTRAIL）对肝癌细胞株SMMC7721的生长抑制效应及凋亡诱导作用．采用显微镜、台盼蓝排斥试验、MTT比色试验、TUNEL法和DNA断裂实验等方法检测细胞增殖和细胞凋亡．通过显微镜观察到核染色质凝集等凋亡的形态学变化，台盼蓝排斥试验、MTT比色试验结果显示，sTRAIL蛋白可显著抑制SMMC7721细胞的生长和增殖，并且TUNEL法检测到经sTRAIL处理后的细胞凋亡指数与对照比较有显著差异，DNA断裂实验亦观察到典型的DNA梯形条带，这些结果提示sTRAIL可诱导肝癌细胞株SMMC7721发生凋亡，具有抗肝癌的作用．     

自噬对肝癌SMMC-7721细胞侵袭迁移能力的影响

为探讨自噬对照射过程中肝癌SMMC-7721细胞侵袭和迁移能力的影响及其潜在的作用机制,将肝癌SMMC-7721细胞分为6组,分别为阴性对照(NC)组、8 Gy X-线照射(IR)组、自噬激活剂雷帕霉素(Rapa)组、自噬抑制剂三甲基腺嘌呤(3-MA)组、照射+雷帕霉素(IR+Rapa)组和照射+三甲基腺嘌呤(IR+3-MA)组,利用划痕实验和Transwell实验检测自噬对肝癌SMMC-7721细胞迁移和侵袭的影响;用CCK8实验检测照射、雷帕霉素和3-MA对肝癌细胞增殖的影响;用蛋白免疫印迹(Western blot)检测N-钙黏蛋白(N-cadherin)、波形蛋白(Vimentin)和LC3B蛋白表达情况。研究结果显示,照射可增强肝癌SMMC-7721细胞侵袭迁移的能力(P<0.05),同时,照射可抑制细胞的增殖能力(P<0.05);雷帕霉素激活自噬可增强细胞的侵袭迁移能力(P<0.05),3-MA抑制自噬可抑制细胞侵袭迁移和细胞的增殖能力(P<0.05)。照射可上调N-cadherin、Vimentin表达水平(P<0.05),激活或抑制自噬可分别增加或抑制N-cadherin、Vimentin蛋白表达水平(P<0.05)。表明X-线照射可激活自噬,促进细胞上皮-间充质转化(Epithelial-Mesenchymal Transition,EMT)的发生。激活自噬可以提高肝癌细胞上皮间质转化进而促进肝癌细胞侵袭迁移;反之,抑制自噬可阻碍肝癌细胞的侵袭迁移。     

茶氟香酰胺对人肝癌细胞生长和迁移的抑制作用

茶氟香酰胺(Ethyl 6-fluorocoumarin-3-carboxylyl L-theanine,TFC)是对茶氨酸进行结构优化后的产物,通过实验研究其对人肝癌细胞(SMMC7721)生长和迁移的抑制作用,并了解其作用机制.MTT和Transwell chamber法分别检测不同浓度的TFC对SMMC7721细胞生长和迁移的影响,流式细胞术分析不同浓度的TFC对SMMC7721细胞凋亡的影响,Western blotting检测不同浓度的TFC组对与SMMC7721细胞中与肿瘤细胞生长、迁移和凋亡密切相关蛋白表达的影响.实验结果显示,TFC能够显著抑制SMMC7721细胞生长、迁移并诱导癌细胞凋亡,TFC药物分子作用机制可能与下调SMMC7721细胞中血管内皮生长因子受体VEGFR1、磷酸化蛋白激酶B(phosphorylated protein kinase B,p AKT)、核转录因子NF-κB、抗凋亡蛋白(BCL2,apoptosis regulator,BCL2)、细胞周期蛋白(cyclin D1,CCND1)表达和上调促凋亡蛋白(BCL2 associated X,apoptosis regulator,BAX)、细胞色素c(cytochrome c,somatic,CYCS)、人体抑癌基因蛋白(tumor protein p53,TP53)、半胱天冬酶3(caspase,CASP3)和E-cadherin蛋白表达有关,TFC抑制人肝癌SMMC7721细胞生长和迁移作用的重要信号通路涉及到VEGFR/AKT/NF-κB.     

血管内皮生长因子反义核酸增强HL60和K562细胞对As2O3的敏感性细胞对As2O3的敏感性

目的:探讨血管内皮生长因子(VEGF)反义核酸能否提高HL60和K562细胞对三氧化二砷(As2O3)的敏感性.方法:采用经筛选所得的最优反义核酸(A7),20个碱基经过全硫代修饰;以脂质体介导转染细胞,反义核酸和As2O3联合作用72 h以后,用MTT法检测细胞生长情况,求IC50值;用ELISA法检测培养液中VEGF蛋白的浓度,用流式细胞仪检测细胞凋亡百分数.结果:VEGF反义核酸可显著降低HL60、K562细胞对As2O3的IC50值,下调VEGF蛋白的表达,增加As2O3诱导的HL60、K562细胞凋亡作用.结论:VEGF反义核酸具有增强HL60和K562细胞对As2O3的敏感性,增强As2O3诱导的HL60和K562细胞凋亡作用;提示内源性VEGF蛋白具有使细胞产生耐药性的作用.     

反义人端粒酶催化亚单位基因转染对人结肠癌细胞恶性表型的逆转作用

利用基因重组技术,人端粒酶催化亚单位基因反向插入真核表达载体pcDNA3.0,获得重组体pcDRTRT,通过脂质体法导入人结肠癌细胞株SW-111C,获得稳定转染细胞系,即反义细胞.该细胞易脱落,出现明显生长抑制现象;失去叠落生长能力;流式细胞仪(FCM)证实导入反义hTRT后,G0/1期细胞增加,G2M和S期细胞减少,增殖指数(PI)降低;且不能在软琼脂中形成集落.说明反义hTRT基因体外导入结肠癌细胞株SW-111C可以明显降低端粒酶活性,抑制结肠癌细胞的增殖且能使其恶性表型发生逆转.     

血管内皮生长因子反义核酸增强HL60和K562细胞对As_2O_3的敏感性

目的:探讨血管内皮生长因子(VEGF)反义核酸能否提高HL60和K562细胞对三氧化二砷(As2O3)的敏感性。方法:采用经筛选所得的最优反义核酸(A7),20个碱基经过全硫代修饰;以脂质体介导转染细胞,反义核酸和As2O3联合作用72h以后,用MTT法检测细胞生长情况,求IC50值;用ELISA法检测培养液中VEGF蛋白的浓度,用流式细胞仪检测细胞凋亡百分数。结果:VEGF反义核酸可显著降低HL60、K562细胞对As2O3的IC50值,下调VEGF蛋白的表达,增加As2O3诱导的HL60、K562细胞凋亡作用。结论:VEGF反义核酸具有增强HL60和K562细胞对As2O3的敏感性,增强As2O3诱导的HL60和K562细胞凋亡作用;提示内源性VEGF蛋白具有使细胞产生耐药性的作用。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

英文诗歌中的喻类修辞

为了有助于提高英文爱好者的个人情操、文化素养和学习兴趣,以及专业人员对英语学习和研究进行多途径的探索,本文通过一些精选诗歌的引证和分析,着重论述了喻类修辞法在英文诗歌中的运用其及效果。     

Man Is Unable to Change the Miserable Life——Analysis of the Arrangement of Four Characters in The Glass Menagerie

Tennessee Williams is considered as one of the most important American playwrights since World War II.The Glass Menagerie is his first successful drama,which describes a tragic situation of family and means to say that Man is unable to change the miserable life,no matter whatever means he try,This essay focuses on the analysis of the arrangement of the four main characters:Laura.Amanda,Jim and Tom to reveal the theme.Laura is fragile.Amanda is brave.Jim is vital.Tom is sensible.And all of them develop and try the different means to struggle against life,but fail tragically.With the evidence,the paper comes to conclusion naturally that Man is unable to change the miserable life,and he dooms to fail.     

Characterization of root-nodulating bacteria on Retama raetam in arid Tunisian soils

The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most effective isolate.     

An Affordable Accurate Evaluation of the Binding Conformations Predicted by Molecular Docking Studies in Bio-System

正Recently,docking has been widely used to predict the binding-modes of protein-inhibitors,when the crystal complexes structure was absent.Most docking algorithms are able to generate a large number of probable conformations,it,however,is difficult to effectively evaluate these docking poses and identify the most reasonable bindingmode.In the present study,on the basis of the crystallographic data of human 3-hydroxy-3-methylglutaryl coenzyme     

WIMAX与WI-FI技术分析及联合组网

介绍了WiMAX与Wi-Fi两种无线宽带接入技术,并对两者之间的关系及相互之间的影响做了对比及分析,并对WiMAX的关键技术进行了详细说明,最后对两者的联合组网方式做了简单的探讨。