肿瘤抑制因子PTEN上调曲妥珠单抗(Trastuzumab)对胃癌细胞BGC-823的杀伤作用

进展胃癌患者往往失去手术等根治性治疗的机会;但目前西妥昔单抗(Cetuximab)、贝伐单抗(Bevacizumab)等分子靶向药物对胃癌极不敏感,仅有少数患者能够从曲妥珠单抗(Trastuzumab)治疗获益。检测肿瘤抑制因子PTEN上调Trastuzumab杀伤胃癌细胞作用及其分子机制。在胃癌细胞系中使用PTEN的抗体检测其表达水平。在最为公认的胃癌研究模型BGC-823细胞中利用脂质体转染PTEN的表达载体,检测其对胃癌细胞增殖等生物学行为的影响;利用系列浓度梯度的Trastuzumab处理胃癌细胞;并计算抑制率和IC_(50)值。在此基础上,利用MTT和Transwell等技术检测转染PTEN的表达载体对Trastuzumab杀伤胃癌细胞的影响。使用蛋白印迹方法(Western Blot,WB)检测PTEN对HER2下游信号通路AKT磷酸化的影响。结果是PTEN在胃癌细胞中的表达水平极低,过表达PTEN能够抑制BGC-823细胞的增殖作用。PTEN能够上调Trastuzumab抑制BG-823细胞的增殖、锚定非依赖性生长、体外侵袭/转移作用。说明PTEN具有对Trastuzumab杀伤胃癌细胞有增敏作用。     

肿瘤抑制基因PTEN的研究进展

评述了PTEN作为一个重要的肿瘤抑制基因,在功能、表达调控机制及与同源基因的关系等方面的最新研究进展. PTEN不仅有脂质磷酸酶活性,还有蛋白磷酸酶活性. 通过这两种活性,PTEN调节细胞的生长、增殖、迁移与凋亡;PTEN基因和蛋白的表达被包括p53,Egr-1,PPARγ与Sp1在内的多种因子调控;PTEN的同源基因PTEN 2是一种肿瘤睾丸抗原基因,在肝癌与肺癌中表达,有用于临床肿瘤免疫治疗的潜能.     

IGF-I、OPN、PTEN蛋白在非小细胞肺癌中的表达及其意义

探讨胰岛素样生长因子1(IGF-I)、骨桥蛋白(OPN)和PTEN在人非小细胞肺癌中的表达及其相关性,并分析其与非小细胞肺癌的关系。应用免疫组织化学SP法检测61例肺癌组织和30例癌旁组织中IGF-I、OPN、PTEN的表达情况。结果显示,①肿瘤组织中IGF-I、OPN蛋白表达显著高于癌旁组织(P<0.05),IGF-I的表达与肿瘤分化程度、淋巴结转移有关(P<0.05),OPN的表达与患者肿瘤分化程度、淋巴结转移、TNM分期有关(P<0.05),肿瘤组织中PTEN蛋白表达明显低于癌旁组织(P<0.05),PTEN的表达与肿瘤大小、肿瘤组织的分化程度、有无淋巴结转移有关(P<0.05)。②IGF-I的表达与OPN的表达呈正相关(P<0.05),IGF-I、OPN与PTEN的表达呈负相关(P<0.05)。研究表明,IGF-I、OPN、PTEN蛋白与非小细胞肺癌的发生发展密切相关,三者的表达对判断肺癌恶性程度和预后具有参考意义。     

PTEN基因在哈萨克族食管癌组织中的表达及意义

通过观察PTEN在哈萨克族食管癌癌组织及相应正常组织中的表达,探讨PTEN基因在哈萨克族食管癌发生中的作用。采用RT-PCR方法检测PTEN基因mRNA在36例哈萨克族食管癌及相应正常组织标本中的表达,选取mRNA水平差异组织标本,采用Western-bolt方法检测其蛋白水平的表达情况。结果显示,PTEN基因mRNA在36例癌组织中有30例表达,阳性率为83.33%。其中癌组织表达量高于相应正常组织(TN)21例,占70%;癌组织表达量等于相应正常组织(T=N)4例,占13.33%;癌组织表达量低于相应正常组织(TN)5例,占16.67%。PTEN基因mRNA在正常组织中表达仅有9例。癌组织与相应正常组织相比,PTEN基因的表达量明显增高。PTEN蛋白的表达在癌组织与相应正常组织中无明显差异。结果表明,PTEN基因的异常表达主要在转录水平,可能不是哈萨克族食管癌发生发展中的主导基因,其对哈萨克族食管癌发生发展过程中的具体作用有待进一步研究。     

蛋白酶体激活因子REGγ的肿瘤相关靶蛋白研究进展

蛋白酶体激活因子REGγ属于蛋白酶体激活因子REG(又名11 S)家族的成员之一,主要是通过激活20 S蛋白酶体以非泛素化和非ATP依赖的方式降解蛋白质.近年来,越来越多的研究表明,REGγ在多种肿瘤中出现了异常表达并与肿瘤的发生发展密切相关.REGγ主要是通过降解多种靶蛋白并调控相关的信号通路参与肿瘤的发生发展.本文综述了REGγ在肿瘤中发挥作用的靶蛋白,旨在进一步了解REGγ参与肿瘤发生发展的机制并揭示其作为人类多种肿瘤的诊断标志物和治疗靶点的潜在可能性.     

P73蛋白在胃炎、不典型增生和胃癌中的表达及意义

目的探讨p73基因在胃癌发生、发展中的作用和意义。方法采用免疫组化技术检测胃炎、轻度不典型增生、中重度不典型增生和胃癌（均为外科手术患者）各30例组织中p73蛋白的表达。结果p73蛋白在胃癌组和不典型增生组中表达高于胃炎组,胃癌组中表达高于不典型增生组（P〈0．05）;p73蛋白的阳性表达率在胃癌的不同的分化度之间有差异,低分化腺癌组织中的阳性表达强度高于高、中分化腺癌（P〈0．05）,p73蛋白在中、重度不典型增生组的阳性表达率与轻度不典型增生组无显著差异（P〉0．05）;在胃癌的不同TNM分期之间也有差异（P〈0．05）,并且TNM分期越高,阳性表达率越高;均与淋巴结转移、肿瘤部位、胃癌侵及层次、肿瘤大小无关（P〉0．05）。结论p73的高表达可能参与了胃癌发生、发展,作为胃癌发生、发展及预后的肿瘤指标物。     

MiR-17促进胃癌细胞上皮间质转化机制

目的 探讨miR-17调控胃癌细胞上皮间质转化的作用机制.方法 检测胃癌组织和胃癌细胞系中miR-17的表达水平;分别将miR-17模拟物(抑制物)和TGFBR2过表达载体(siRNA)转染到SGC-7901胃癌细胞中,通过MTT法、流式细胞术、Transwell实验和Western blotting检测细胞增殖、凋亡、侵袭和EMT标志蛋白表达;荧光素酶报告基因分析验证miR-17与TGFBR2的靶向关系.结果 胃癌组织和胃癌细胞系中miR-17表达上调;过表达miR-17促进SGC-7901细胞增殖、侵袭,抑制凋亡;miR-17靶向TGFBR2的3'UTR;过表达TGFBR2抑制SGC-7901细胞增殖、侵袭,促进凋亡;miR-17通过激活PTEN/PI3K/AKT信号通路促进SGC-7901细胞EMT.结论 miR-17靶向下调TGFBR2表达,激活PTEN/PDK/AKT信号通路,促进SGC-7901细胞EMT.体内研究结果证明miR-17促进肿瘤的生长.因此,miR-17可能是胃癌抗转移治疗的潜在策略.     

PTEN和FHIT在口腔鳞癌中的表达及意义

目的：检测抑癌基因VIEN、FHIT在正常口腔黏膜上皮和口腔鳞癌中的表达情况，并探讨其与肿瘤组织学类型的关系。方法：采用SP法免疫组化方法检测62例口腔鳞癌中和12例正常口腔黏膜中FHIT、PTEN的蛋白表达。结果：在正常口腔黏膜中PTEN均为强阳性表达(12／12)，在口腔鳞癌中24．2％(15／62)表现为PTEN蛋白表达的缺乏或减少；而FHIT在正常口腔黏膜中也均为强阳性表达(12／12)；在口腔鳞癌中17．7％(11／62)表现为FHIT蛋白表达缺乏或减少。结论：PTEN、FHIT在口腔鳞癌的发生过程中起着一定的作用。     

CD147与恶性肿瘤关系的研究进展

CD147是广泛表达于人体多个组织的跨膜糖蛋白,属于免疫球蛋白超家族。CD147在不同组织中呈现不同水平的表达,此外其在不同种属间的表达亦存在很大差异,有研究表明CD147在多种生理及病理过程起重要作用。经检测CD147在多种恶性肿瘤中均呈现高水平表达,在肿瘤的发生发展中,CD147通过诱导基质金属蛋白（MMPs）的产生,实现对肿瘤生长、浸润及转移的促进作用。     

MCM6/PCNA在胃癌中的表达及相关性分析

为了探究MCM6和PCNA表达量与胃癌的发生发展之间的关系,并进一步探讨MCM6/PCNA作为胃癌标志物的可能性,采用GEPIA数据库分析对比MCM6和PCNA在胃癌细胞中的表达,并对收集到的胃癌标本进行免疫组织化学染色,观察染色结果.随后利用shRNA敲低胃癌细胞系MGC-803和AGS中MCM6,分别利用MTT、克隆形成以及Western Blot分析MCM6与肿瘤细胞增殖的关系,再采用小鼠肿瘤体内生长实验分析MCM6对体内肿瘤生长的作用.最后通过数据分析得出研究结果,即MCM6和PCNA对胃癌的影响.结果表明:GEPIA数据库的数据显示MCM6和PCNA在胃癌中的表达量显著上调,且MCM6与PCNA的表达显著正相关(R=0.65;P<0.01).进行免疫组织化学染色分析MCM6与胃癌之间的关系,发现MCM6与胃癌的肿瘤大小明显相关(P=0.010),且MCM6低表达的胃癌患者的PCNA表达量也相应下调.MTT实验和克隆形成实验表明MCM6的表达抑制会显著降低胃癌细胞的增殖,而体内实验可表明MCM6表达下调可抑制胃癌细胞的体内增殖.上述结果说明MCM6/PCNA的表达量与胃癌...     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that