1α,25（OH）2D3通过阻滞细胞周期抑制胃癌细胞系增殖简

 目的 研究1α,25(OH) 2D3对胃癌细胞增殖和细胞周期的影响,并探讨其相关的作用机制。方法 BGC-823和SGC-7901胃癌细胞株分别给予终浓度为10-10~10-7mol/L的1α,25(OH) 2D3处理72h,用MTT法检测细胞抑制率;用流式细胞仪检测细胞周期;用RT-qPCR技术检测细胞周期相关基因P21、cyclinD1、cyclinE1和CDK6 mRNA表达。 结果1α,25(OH) 2D3对胃癌细胞的增殖抑制率具有浓度依赖性, 1α,25(OH) 2D3干预导致BGC-823和SGC-7901细胞株G1期细胞比例升高,S期细胞比例降低 (P<0.05); 1α,25(OH) 2D3干预后,BGC-823和SGC-7901胃癌细胞P21 mRNA表达升高(P<0.01),而cyclinD1、cyclinE1和CDK6 mRNA表达降低(P<0.01)。结论 1α,25(OH) 2D3抑制胃癌细胞增殖,诱导细胞周期阻滞,可能与上调P21,下调cyclinD1、cyclinE1和CDK6的表达有关。     

miR-195在胃癌细胞中的表达及对癌细胞凋亡的机制研究

目的探讨miR-195在胃癌细胞中的表达及对癌细胞凋亡的影响和机制。方法以人胃黏膜正常细胞GES-1作为对照,RT-PCR检测人胃癌MNK-28、SGC-7901、BGC-823细胞中mi R-195基因的表达;将mi R-195 mimics转染BGC-823细胞,48 h后RT-PCR检测mi R-195的mR NA表达;流式细胞仪检测细胞凋亡;Western blot检测cleaved caspase3、Notch1、Hes1蛋白表达。结果 mi R-195在MNK-28、SGC-7901、BGC-823细胞中的mR NA表达均显著低于GES-1(P0.01),miR-195在BGC-823细胞中的表达最低,选择作为后续研究对象;过表达组细胞凋亡率及cleaved caspase3蛋白表达显著高于对照组,Notch1、Hes1蛋白表达显著低于对照组(P0.01),而空转染组细胞凋亡率及cleaved caspase3、Notch1、Hes1蛋白表达与对照组差异无统计学意义(P0.05)。结论 mi R-195在胃癌细胞的过表达可促进癌细胞的凋亡,其机制与下调cleaved caspase3蛋白表达及Notch1信号通路有关。     

1α,25(OH)_2D_3通过阻滞细胞周期抑制胃癌细胞系增殖

目的研究1α,25(OH)2D3对胃癌细胞增殖和细胞周期的影响,并探讨其相关的作用机制。方法 BGC-823和SGC-7901胃癌细胞系分别给予终浓度为1×10-10～1×10-7mol/L的1α,25(OH)2D3处理72 h,用MTT法检测细胞抑制率;用流式细胞仪检测细胞周期;用RT-qPCR技术检测细胞周期相关基因P21、cyclin D1、cyclin E1和CDK6 mRNA表达。结果 1α,25(OH)2D3对胃癌细胞的增殖抑制率具有浓度依赖性,1α,25(OH)2D3干预导致BGC-823和SGC-7901细胞系G1期细胞比例升高,S期细胞比例降低(P0.05);1α,25(OH)2D3干预后,BGC-823和SGC-7901胃癌细胞P21 mRNA表达升高(P0.01),而cyclin D1、cyclin E1和CDK6 mRNA表达降低(P0.01)。结论 1α,25(OH)2D3抑制胃癌细胞增殖,诱导细胞周期阻滞,可能与上调P21,下调cyclin D1、cyclin E1和CDK6的表达有关。     

姜黄素调控Wnt信号通路抑制胃癌细胞上皮间质转化的研究

目的探讨姜黄素对人胃癌细胞株BGC-823上皮间质转化(EMT)的影响机制。方法将细胞分为姜黄素干预组、TGF-β组、BGC-823细胞对照组、GES-1细胞对照组。采用姜黄素(10μmol/L)干预人胃癌细胞株BGC-823,通过MTT试验检测胃癌细胞增殖能力;通过Transwell小室试验检测胃癌细胞侵袭功能改变;通过Western blot检测各组细胞E-cadherin、Vimentin蛋白及Wnt信号通路相关蛋白表达。结果 TGF-β诱导能够促进人胃癌细胞株BGC-823增殖(P 0.05),胃癌细胞表现出更高的侵袭能力(P 0.01),而姜黄素干预后胃癌细胞的增殖及侵袭能力均明显受抑制。Western blot检测表明,TGF-β诱导干预后,BGC-823细胞E-cadherin、Vimentin蛋白水平升高,与此同时GSK3β、β-catenin及c-Myc的表达明显上调(P 0.01);姜黄素干预能有效抑制胃癌细胞EMT作用,Wnt信号通路蛋白水平显著下调(P 0.05)。结论姜黄素可以通过调控Wnt/β-catenin信号通路抑制胃癌细胞EMT作用,从而抑制肿瘤细胞的侵袭、转移,实现抗肿瘤作用。     

FERM和merlin蛋白对不同分化程度胃癌细胞生物学功能的调节

目的研究FERM和merlin蛋白对不同分化程度胃癌细胞生物学功能的调节作用。方法利用Lipofectamine 2000将重组质粒FERM、merlin-1和-2,以及空白对照质粒分别转染到不同分化程度胃癌细胞BGC-823、MGC-803、SGC-7901和正常胃粘膜细胞GES-1中,培养36 h后用MTT检测法检测细胞增殖,用transwell方法检测细胞黏附侵移能力。结果与对照组相比,转染FERM、merlin-2蛋白到不同分化程度胃癌细胞(BGC-823、MGC-803、SGC-7901)、正常胃粘膜细胞(GES-1)后,发现对细胞增殖、细胞黏附侵移能力没有影响(P0.05);而转染merlin-1蛋白后,无论对不同分化程度胃癌细胞、还是正常胃粘膜细胞的增殖、细胞黏附能力均有显著抑制作用(P0.05)。结论 merlin-1对胃癌细胞和正常胃粘膜细胞增殖、黏附侵移能力有抑制作用。     

miRNA-542-3p对胃腺癌细胞侵袭转移能力的影响

目的研究microRNA-542-3p(miR-542-3p)在人胃腺癌细胞系及组织中的表达水平及对胃腺癌细胞侵袭转移的影响。方法通过RT-PCR检测miR-542-3p在人正常胃粘膜上皮细胞GES-1及人胃癌细胞系SGC-7901和BGC-823中的表达水平;同时应用RT-PCR检测miR-542-3p在50组患者胃腺癌和癌旁组织中的表达差异。体外实验通过外源转染miR-542-3p的模拟物和抑制剂,分别于24,36,48h检测SGC-7901的转染效率,选取最佳转染时间。应用划痕实验和Transwell评估细胞侵袭转移能力的变化。结果胃腺癌细胞系SGC-7901和BGC-823中miR-542-3p的表达水平低于其在GSE-1中的表达水平(P0.05);miR-542-3p在癌组织中表达低于癌旁组织(P0.05)。24 h后,miR-542-3p模拟物组侵袭转移能力显著低于对照组(P0.05),而miR-542-3p抑制剂组侵袭转移能力显著高于对照组(P0.05)。结论miR-542-3p在多种人胃癌细胞和胃腺癌组织中呈低表达,miR-542-3p抑制胃腺癌SGC7901细胞的侵袭转移能力。     

LncRNA SLC16A1-AS1 通过靶向 miR-15a-5p 负向调控子宫颈癌细胞的增殖和侵袭

目的探讨LncRNA SLC16A1-AS1通过靶向miR-15a-5p调控子宫颈癌细胞增殖和侵袭的作用机制。方法采用qRT-PCR法检测SLC16A1-AS1在子宫颈癌组织、癌旁组织、人正常子宫颈上皮细胞(H8)及子宫颈癌细胞株(HeLa、HCC94、SiHa、C33A)中的表达水平。选择SLC16A1-AS1表达最少的子宫颈癌细胞株,分别转染阴性质粒和SLC16A1-AS1过表达质粒,标记为NC组和SLC16A1-AS1组。应用MTT法和Transwell实验分别检测过表达SLC16A1-AS1对子宫颈癌细胞增殖和侵袭能力的影响。生物信息学网站预测及双荧光素酶报告基因实验,验证SLC16A1-AS1与靶基因的靶向关系。qRT-PCR和Western blot法检测靶基因及相关蛋白的表达。结果子宫颈癌组织中SLC16A1-AS1的表达水平显著低于癌旁组织(P0.01)。与H8细胞相比,HeLa、HCC94、SiHa、C33A细胞中SLC16A1-AS1的表达水平降低(P0.05)。与NC组相比,过表达SLC16A1-AS1的C33A细胞增殖能力降低(P0.05),过表达SLC16A1-AS1的C33A细胞侵袭数下降(P0.01)。生物信息学网站预测显示,SLC16A1-AS1可与miR-15a-5p有特异性结合位点。双荧光素酶报告基因实验结果证实SLC16A1-AS1可与miR-15a-5p直接结合(P0.01)。SLC16A1-AS1可负向调控miR-15a-5p的表达(P0.01)。与NC组相比,SLC16A1-AS1组细胞增殖表型蛋白(如PCNA、Ki-67)和细胞侵袭表型蛋白(如N-cadherin、Slug)表达均降低。结论 SLC16A1-AS1在子宫颈癌中低表达,SLC16A1-AS1通过靶向下调miR-15a-5p的表达,抑制子宫颈癌细胞C33A的增殖和侵袭。     

siRNA沉默Nox1基因抑制胃癌细胞的生长

目的: 探讨siRNA沉默NADPH氧化酶1(Nox1)基因表达对胃癌细胞的生长抑制作用。方法: 合成Nox1 siRNA, 采用实时定量PCR 和Western blotting观察Nox1 siRNA 转染后胃癌SGC-7901细胞Nox1 mRNA及相应蛋白表达的变化; 用CCK-8细胞增殖实验、流式细胞检测技术分别检测胃癌SGC-7901细胞增殖及凋亡的变化。结果: 转染Nox1 siRNA 后的胃癌SGC-7901细胞Nox1 mRNA及蛋白表达明显受抑制。与对照组相比, 干扰组SGC-7901细胞生长明显变缓(P<0.05), 细胞凋亡率明显增高(P<0.01)。结论: Nox1 siRNA 可明显下调靶基因Nox1的表达, 在体外可抑制胃癌SGC-7901细胞的生长并促进其凋亡。     

PRRX2通过调控Wnt/β-catenin信号通路促进胃癌细胞活力和迁移

目的:研究配对相关同源框2(paired-related homeobox 2,PRRX2)基因对胃癌细胞活力和迁移能力的影响,并分析其调控Wnt/β-catenin信号通路的机制。方法:通过生物信息学分析在线数据库中胃癌和正常胃组织的PRRX2表达水平及PRRX2在胃癌组织中的表达与胃癌患者总生存率的相关性;将PRRX2小干扰RNA(si RNA)和过表达质粒分别转染到胃癌细胞MGC-803和SGC-7901中,敲低和过表达PRRX2基因;MTT法和Transwell实验检测胃癌细胞的活力和迁移能力;Western blot和TOPflash/FOPflash双萤光素酶报告基因实验检测Wnt/β-catenin信号通路的活化情况;免疫共沉淀实验检测PRRX2与β-catenin蛋白的相互作用。结果:敲低PRRX2能够减弱胃癌细胞MGC-803的活力和迁移能力(P0.05)。过表达PRRX2能够增强胃癌细胞SGC-7901的活力和迁移能力(P0.05),增加β-catenin、c-Myc和cyclin D1的蛋白的表达水平(P0.05),增强TOPflash/FOPflash双萤光素酶报告基因活性(P0.05)。PRRX2与β-catenin蛋白存在相互作用。结论:PRRX2可促进胃癌细胞的活力和迁移,其机制可能与Wnt/β-catenin信号通路有关。     

miR-134-3p靶向细胞周期蛋白D1抑制胃癌细胞增殖的作用及机制

目的：研究mi R-134-3p靶向细胞周期蛋白D1(CCND1)抑制胃癌细胞增殖的作用及机制。方法：收集手术切除的胃癌组织及癌旁组织，培养正常胃黏膜上皮细胞株GES-1及胃癌细胞株MGC-803、SGC-7901、BGC-823，检测mi R-134-3p、CCND1的表达水平；BGC-823细胞分组并转染阴性对照(NC)模拟物或mi R-134-3p模拟物、感染NC腺病毒或CCND1腺病毒，检测细胞增殖抑制率、细胞周期比例、mi R-134-3p及CCND1表达水平；双荧光素酶报告基因验证mi R-134-3p与CCND1的靶向结合；饲养BALB/c裸鼠，皮下注射感染NC腺病毒或mi R-134-3p腺病毒的BGC-823，成瘤后测定移植瘤质量、体积及CCND1表达水平。结果：与癌旁组织相比，胃癌组织中mi R-134-3p表达水平明显降低、CCND1表达水平明显升高(P<0.05)，且mi R-134-3p与CCND1呈负相关；与GES-1细胞相比，BGC-823、MGC-803、SGC-7901细胞中mi R-134-3p表达水平明显降低，CCND1表达水平明显升高(P&...     

Interferon-Inducible Cholesterol-25-Hydroxylase Broadly Inhibits Viral Entry by Production of 25-Hydroxycholesterol

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Highlights? CH25H inhibits viral growth by production of an oxysterol, 25-hydroxycholesterol ? 25HC inhibits replication of VSV, HSV, HIV, MHV68, EBOV, NiV, RSSEV, and RVFV ? 25HC inhibits viral fusion of VSV and HIV ? In vivo, 25HC suppresses HIV growth and Ch25h is required for antiviral immunity     

The 25 Years of Neomycin

Abstract

The year 1974 marked the 20th anniversary of the dedication of the Institute of Microbiology of Rutgers University and the official changing of its name to The Waksman Institute of Microbiology. It was also the expiration date of the U.S. Patent No. 2,799,620, “Neomycin and Process of Preparation,” granted in 1957 to Dr. Selman A. Waksman and to me and assigned to the Rutgers Research and Educational Foundation. Nineteen seventy-four also marked the 25th year following the announcement of the discovery of neomycin, but the tale of neomycin goes further back in time.     

25 Jahre Wassermannsche Reaktion

Ohne Zusammenfassung     

The C-terminal part of the CDC25 gene product has Ras-nucleotide exchange activity when present in a chimeric SDC25-CDC25 protein

The CDC25 gene from S. cerevisiae encodes an activator of Ras proteins. The C-terminal part of a structurally-related protein encoded by the SDC25 gene is characterised by a Ras-guanine nucleotide exchange activity in vitro whereas the C-terminal part of CDC25 gives no detectable exchange activity. A chimera between the 3 regions of these two genes was constructed by homeologous recombination. This chimeric gene suppresses cdc25 mutations. When expressed in E. coli, the chimeric product is detectable by antibodies directed against the carboxy-terminal CDC25 peptide and has an exchange-factor activity on the Ras2 protein. Therefore, the carboxy-terminal parts of both the CDC25 and the SDC25 gene products are structurally and functionally similar. The CDC25 part of the chimeric protein contains an intrinsic guanine exchange factor which does not require an additional cofactor.     

Omalizumab: anti-IgE monoclonal antibody E25, E25, humanised anti-IgE MAb,IGE 025, monoclonal antibody E25, Olizumab,Xolair, rhuMAb-E25

Omalizumab [anti-IgE monoclonal antibody E25, E25, humanised anti-IgE MAb, IGE 025, monoclonal antibody E25, olizumab, rhuMAb-E25, Xolair] is a chimeric monoclonal antibody. It binds specifically to the Cepsilon3 domain of immunoglobulin E (IgE). Cepsilon3 is the site of high-affinity IgE receptor binding. IgE plays a major role in allergic disease by causing the release of histamine and other inflammatory mediators from mast cells. Omalizumab binds to and neutralises circulating IgE by preventing IgE from binding to its high-affinity mast-cell receptor. In addition, omalizumab does not bind to or induce histamine release from basophils, nor does it bind to or recognise IgG. The immune complexes formed between IgE and omalizumab in vivo are relatively small (molecular weight <1 million) and are therefore unlikely to cause organ damage. COLLABORATION BETWEEN GENETECH NOVARTIS AND TANOX: omalizumab is very similar to the Tanox product CGP 51901. Genentech (Roche), Novartis and Tanox (formerly Tanox Biosystems) were developing both antibodies in phase II studies, with an agreement to collaborate on phase III development of the most promising one. The Genentech product, omalizumab, was selected for further development. Tanox has marketing rights to the drug in some Asian markets. Novartis and Genentech have marketing rights in the USA. Roche has an option to participate in the commercialisation of omalizumab and other anti-IgE products of the collaboration in Japan and Europe. Roche may exercise this option if specific events relating to commercialisation of the product occur; Roche has waived this option for omalizumab in Japan. If Genentech withdraws from the collaboration, Roche has an option to assume its place. Either Novartis or Genentech may withdraw from the collaboration on short notice, in which case rights to omalizumab revert to Tanox and the remaining collaborator unless Roche exercises its option in the event of withdrawal by Genentech. PATENTS: Protein Design Labs holds fundamental antibody humanisation patents. Protein Design Labs stated in its Annual Report for 2000 that Genentech may elect to take a patent licence for Xolair under a 1998 patent rights agreement. CLINICAL TRIALS: Phase III clinical trials of omalizumab for the treatment of allergic rhinitis and allergic asthma were in progress with Genentech (Roche) in the USA, Canada, Europe and Japan, and are now completed. In New Zealand, the antibody was investigated in clinical trials for the treatment of allergic asthma at the Wellington School of Medicine. In the phase III trials, omalizumab was administered as a subcutaneous injection. It may also be administered intravenously. In additional phase I and II studies, the safety and efficacy of aerosol administration for allergic asthma was tested. Initial results of these studies indicated that aerosol administration is less effective than intravenous or subcutaneous administration. TEMPORARY SUSPENSION OF TRIALS: In September 2000, the US FDA requested that Genentech and Novartis suspend new trials of omalizumab. Existing long-term trials, however, could continue. The hold on new trials was due to concerns about the preclinical toxicity of omalizumab and the follow-up antibody E26. Thrombocytopenia was reported in studies in monkeys for omalizumab at 5-27 times the maximum clinical dose and for E26 at 3-15 times the maximum dose. In response to FDA requests, Novartis and Genentech carried out additional preclinical trials so that a specific explanation of the toxicity could be obtained; Novartis suspected a species specificity for the adverse events, as no thrombocytopenic events occurred in the completed phase III clinical trials. The supplementary data were submitted to the FDA and the hold on clinical trials was lifted in November 2000. REGULATORY FILINGS: in June 2000, Genentech, Novartis and Tanox submitted a Biologics Licence Application (BLA) to the US FDA for approval of omalizumab for the treatment of allergic asthma and allergic rhinitis. Novartis fileiled for marketing approval of omalizumab in the European Union, Switzerland, Australia and New Zealand. INDICATION NARROWED TO ADULT ALLERGIC ASTHMA: In July 2001, the FDA requested additional data, both preclinical and clinical, for Xolair, as well as more detailed information concerning the effect of prolonged action of the drug. Genentech is to satisfy the FDA's request with data from the ALTO platelet monitoring safety study and with ongoing open-label studies. Genentech, Novartis and Tanox believe that substantial information can be provided from continuing trials, but additional trials on specific subgroups may be necessary. The new data will be submitted to both the US FDA and the EMEA in the European Union. The application for approval of Xolair that was submitted to the EMEA was withdrawn when it became clear that there would be a delay in approval in the USA. Tanox had originally anticipated that Xolair would be launched in mid-2001 in the USA and Europe. In November 2001, Genentech and Novartis stated that an amended BLA would be submitted to the FDA in the fourth quarter of 2002. The amended approval application will focus on the use of Xolair in adults only with allergic asthma. The original application was for treatment of both adults and children, and included allergic rhinitis. Genentech has stated that it will first pursue the narrower indication before filing supplemental BLAs. Approval of the drug in the USA may now be delayed until as late as the end of 2003. In Europe, Novartis is planning to develop Xolair for use only in asthmatic patients who are classed as being 'at risk', i.e. those who have been hospitalised or have visited an emergency department. Clinical studies are to be carried out, with submission for regulatory approval planned for 2003. APPROVAL IN AUSTRALIA: In June 2002, Xolair was approved by the Therapeutic Goods Administration in Australia for the treatment of adults and adolescents with moderate allergic asthma. This is the first marketing approval for Xolair.