非病毒基因载体介导短发夹RNA转染抑制肿瘤细胞生长

利用肿瘤细胞表面抗原G250的单克隆抗体G250mAb和聚乙二醇(PEG)修饰非病毒基因载体聚乙烯亚胺(PEI), 获得肿瘤靶向基因载体G250mAb-PEI-PEG. 该载体对HeLa细胞的基因转染效率达到70%, 远远高于对非肿瘤细胞NIH3T3 30%的转染效率. 通过该基因载体将Nucleostemin(NS)基因的特异性短发夹RNA (short hairpin RNA, shRNA)高效率地转入靶细胞HeLa, RNA干扰下调了细胞中NS的表达, 显著抑制了HeLa细胞的增殖能力, 引起HeLa细胞凋亡, 而对NIH 3T3细胞的增殖和活性没有显著影响. 研究结果表明, 非病毒基因载体G250mAb-PEI-PEG可靶向性、高效率的转染HeLa细胞, 应用于基因治疗, 这对于宫颈癌的临床治疗具有重要的意义.     

国外科技期刊亮点

科学家鉴别出抑制HIV病毒基因美国Gladstone病毒学与免疫学研究所Mario L. Santiago和Warner C. Greene等证明,基因Rfv3就是基因Apobec3(带有抗逆转录病毒活性的先天免疫基因)。     

科学家揭示埃博拉古老家族史

<正>据国外媒体报道,美国布法罗大学的科学家成功揭示了埃博拉病毒的家族史。研究发现埃博拉和马尔堡病毒都是线状病毒家族成员,它们的祖先拥有悠久的历史,至少可追溯到1600万到2300万年前。科学家指出,这一发现不但有助于研制埃博拉疫苗,也改写了埃博拉的家族史。此外,这项研究加深了科学家对线状病毒的认知。专家们一度认为线状病毒在大约1万年前出现,     

非典疑凶如何找到

<正> 科学的确提供了许多方便。20世纪70年代,科学家花了7年时间才找到莱姆关节炎的病原体;80年代,科学家花了3年时间才找到艾滋病的病原体;而现在破译非典型肺炎的速度简直是个奇迹:短短七周内,科学家已经完成识别、     

壳聚糖在新型给药系统中的最新应用进展

壳聚糖作为新型药用辅料，已受到越来越多的关注，对其应用的开发和研究已渗透到了药剂学的多个领域。壳聚糖作为非病毒基因载体，是近年来主要的研究热点之一；将其应用于眼部、鼻腔及口腔给药，以及作为胃部、小肠和结肠的特异性给药载体，在近两年内也有大量报道。     

人类与病毒艰难作战 动物的警告

正埃博拉病毒被科学家所关注是从1976年9月29日开始的。这一天,比利时安特卫普的一所微生物学实验室接收了一份来自非洲国家刚果(金)的血液样本包裹,这一血液样本是从刚果埃博拉附近一种流行病患者体内采集的。这位患者是在刚果工作的一位比利时修女,她感染上了一种奇怪的病,并被诊断为疑似黄热病。她尽管接种了全部疫苗,最终还是死亡了。病毒学家通过显微镜照片看到,这种病毒呈长丝状体、像虫子一样结构,和黄热病病毒完全不同,而与马尔堡病毒类似。马尔堡病毒是德国学者在1967年秋发现的新病毒,一些药厂工人被出口自乌干达的一批猴子传     

In situ airborne virus inactivation by microwave irradiation

Infectious diseases cause tremendous costs of both human and economy annually. Previously, we have studied the bacterial, fungal, and allergen aerosol inacti- vation by direct microwave irradiation. Here, we further investigated its effects on airborne viruses. MS2 coliphage used as a human model virus was aerosolized and exposed to the direct microwave irradiation for ,-~ 2 min at three different power levels （700, 385, and 119 W）. In addition to the survival rate, the viral genes before and after the microwave treatments were also examined using PCR and gel electrophoresis. Direct exposure of airborne MS2 viruses to the microwave irradiation at 700 W for less than 2 min was shown to result in more than 90 % inactivation efficiency, about 65 % at medium power level （385 W）, and 50 % at the lowest level （119 W）. The aerosol inac- tivation rate followed a linear relationship with the microwave exposure time （R2 ---- 0.9889）. Scanning elec- tron images revealed visible damages to the viral surface after the exposure. Damages were also observed to the viral RNA genes coding for coat proteins, among which the A protein gene was completely destroyed. This study dem- onstrated that even without the filtration the direct micro- wave irradiation could also achieve rapid inactivation of viral aerosols. The information obtained can provide useful guidance on the development of microwave-based viral threat mitigation solutions in a closed or semi-closed space.     

Non-viral gene carrier mediated short hairpin RNA interference for inhibition of tumor cells growth

A tumor-targeting gene vector G250mAb-PEI-PEG has been prepared by modification of polyethylenimine （PEI） with polyethyleneglycol （PEG） and G250, a monoclonal antibody against the G250 antigen on tumor cell surface. The transfection efficiency was as high as 70% in G250 positive HeLa cells, whereas the transfection efficiency was relatively low （30%） in normal NIH3T3 cells. A plasmid encoding the short hairpin RNA （shRNA） specific for nucleostemin gene （NS） was efficiently transfected into the HeLa cells with this nonviral gene vector. RNA interference down-regulated the expression of NS gene in HeLa cells, inhibited cells proliferation and induced apoptosis. However, the growth and activity of the NIH3T3 cells were not affected under the same treatment. These results indicate that the reported nonviral gene vector, G250mAb-PEI-PEG, can target and efficiently deliver genes into HeLa cells, and has the potential for the cervical cancer treatment.     

马铃薯遗传转化系统的优化及禽流感病毒(H5N1)基因的导入

通过对以马铃薯（Ｓｏｌａｎｕｍ ｔｕｂｅｒｏｕｓｍ Ｌ．）块茎为受体的农杆力菌转化系统进行优化,筛选出使三个品种（鲁引１号、克新３号、优金）的受体均可得高频分化的培养基：ＭＳ＋２．０ｍｇ／Ｌ ＢＡ＋３。０ｍｇ／Ｌ ＺＴ＋０．５ｍｇ／Ｌ ＮＡＡ＋０．５ｍｇ／Ｌ ＧＡ。对几种农杆菌转化条件的比较研究发现,菌体用Ｍｓ＋０．５ｍｇ／Ｌ ＧＡ流体重悬并稀释４倍屿受体于２８℃,１００ｒ／ｍｉｎ振荡侵染２０～３