11 resultados para Neu Oncogene

em Chinese Academy of Sciences Institutional Repositories Grid Portal


Relevância:

20.00% 20.00%

Publicador:

Resumo:

为了探索抗HER2/neu单链抗体与TNF-α联合应用对表面过度表达HER2/neu卵巢癌细胞的生物效应,同时构建了抗HER2/neu单链抗体scFvC6.5的原核表达载体和人TNF-α的原核表达载体,将上述两种重组子分别转化入感受态宿主菌BL21(DE3),得到稳定表达.表达产物主要以包含体形式存在;包含体经过溶解、变性、复性和纯化,得到了分纯的产物.SDS-PAGE和Western-blot检测结果证实,蛋白表达正确.ELISA法验证了scFvC6.5和人TNF-α具有与卵巢癌细胞SKOV-3的结合活性.MTT细胞毒活性试验进一步表明,相对于单独使用TNF-α,联合应用上述两个重组蛋白细胞毒效应明显提高,SKOV-3细胞对TNF-α的敏感性增强.这将为抗HER2/neu抗体的联合抗肿瘤疗法提供一种新的途径,具有潜在的临床应用价值.图5参23

Relevância:

10.00% 10.00%

Publicador:

Resumo:

目的:探索以Lentivirus为载体,构建同时携带并表达多基因的基因工程人胚神经干细胞(hum an neu鄄ral stem cell,hNSC)的可行性,为脊髓损伤治疗的研究提供材料。方法:培养和鉴定hNSC;用携带绿色荧光蛋白(green fluorescence protein,GFP)和神经营养因子-3(neurotrophic factor-3,NT-3)的Lentivirus转染hNSC;用荧光显微镜观察、鼠胚背根神经结培养(dorsal root ganglion,DRG)和Slot blot等方法检测基因工程hNSC的多基因表达情况。结果:培养获得了大量的hNSC;荧光显微镜观察到几乎100%的hNSC表达GFP;基因工程hNSC的培养液能促使大鼠DRG旺盛生长;Slot blot检测到基因工程hNSC能高效分泌NT-3蛋白。结论:以Lentivirus为载体能构建同时携带并稳定表达多基因的基因工程hNSC,为脊髓损伤治疗的基础研究及进一步临床应用提供了有价值的细胞资源。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Microcystins (MCs) are a potent liver tumor promoter, possessing potent tumor-promoting activity and weak initiating activity. Proto-oncogenes are known to be involved in the tumor-promoting mechanisms of microcystin-LR. However, few data are available on the effects of MCs oil proto-oncogenes in the whole animal. To investigate the effects of MCs on the expression profile of the proto-oncogenes in different organs, male Wistar rats were injected intravenously with microcystin extracts at a dose of 86.7 mu g MC-LR eq/kg bw (MC-LR eq, MC-LR equivalents). mRNA levels of three proto-oncogenes c-fos, c-jun and c-myc in liver, kidney and testis were analyzed using quantitative real-time PCR at several time points post-injection. Significant induction of these genes at transcriptional level was observed in the three organs. In addition, the increase of mRNA expression of all three genes was much higher in liver than in kidney and testis. Meanwhile, the protein levels of c-Fos and c-Jun were investigated by western blotting. Both proteins were induced in the three organs. However, elevations of protein levels were Much lower than those of mRNA levels. These findings suggest that the expression of c-fos, c-jun and c-myc might be one possible mechanism for the tumor-promoting activity and initiating activity of microcystins. (c) 2008 Published by Elsevier Ltd.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Upregulated gene 19 (U19)/ELL-associated factor 2 (Eaf2) is a potential human tumor suppressor that exhibits frequent allelic loss and downregulation in high-grade prostate cancer. U19/Eaf2, along with its homolog Eaf1, has been reported to regulate transcriptional elongation via interaction with the eleven-nineteen lysine-rich leukemia (ELL) family of proteins. To further explore the tumor-suppressive effects of U19/Eaf2, we constructed and characterized a murine U19/Eaf2-knockout model. Homozygous or heterozygous deletion of U19/Eaf2 resulted in high rates of lung adenocarcinoma, B-cell lymphoma, hepato cellular carcinoma and prostate intraepithelial neoplasia. Within the mouse prostate, U19/Eaf2 defficiency enhanced cell proliferation and increased epithelial cell size. The knockout mice also exhibited cardiac cell hypertrophy. These data indicate a role for U19/Eaf2 in growth suppression and cell size control as well as argue for U19/Eaf2 as a novel tumor suppressor in multiple mouse tissues. The U19/Eaf2 knockout mouse also provides a unique animal model for three important cancers: lung adenocarcinoma, B-cell lymphoma and hepatocellular carcinoma.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Silver crucian carp (Carassius auratus gibelio) is a unique gynogenetic fish. Because of its specific genetic background and reproduction mode, it is an intriguing model system for understanding regulatory mechanism of oocyte maturation division. It keeps its chromosomal integrity by inhibiting the first meiotic division (no extrusion of the first pole body). The spindle behavior during oocyte maturation is significantly different from that in gonochoristic fish. The chromosomes are first arranged in a tripolar spindle, and then they turn around and are reunited mutually to form a normal bipolar spindle. A new member of the fish A-type cyclin gene, cyclin A2, has been isolated by suppression of subtractive hybridization on the basis of its differential transcription in fully-grown oocytes between the gynogenetic silver crucian carp and gonochoristic color crucian carp. There are 18 differing amino acids in the total 428 residues of cyclin A2 between the two forms of crucian carps. In addition, cDNAs of cyclin A1 and cyclin B have also been cloned from them. Thus two members of A-type cyclins, cyclin A1 and cyclin A2, are demonstrated to exist in fish, just as in frog, humans, and mouse. Northern blotting reveals that cyclin A2 mRNA is more than 20-fold and cyclin A1 mRNA is about 2-fold in fully grown oocytes of gynogenetic silver crucian carp compared to gonochoristic color crucian carp. However, cyclin B does not show such a difference between them. Western blot analysis also shows that the cyclin A2 protein stockpiled in fully grown oocytes of gynogenetic crucian carp is much more abundant than in gonochoristic crucian carp. Moreover, two different cyclin A2 expression patterns during oocyte maturation have been revealed in the two closely related crucian carps. For color crucian carp, cyclin A2 protein is translated only after hormone stimulation. For silver crucian carp, cyclin A2 protein can be detected throughout the process of maturation division. The different expression of cyclin A2 may be a clue to understanding the special maturation division of gynogenetic silver crucian carp.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

提出了一种基于仿生模式识别(Biomimatic Pattern Recognition)和多权值神经元网络(Multi-Weights.Neu-ral Network)的人脸识别新方法.对仿生模式识别理论在人脸识别中的应用模型作了讨论,并且介绍了一种新的人脸特征提取方法.本文通过实验对本文提出的基于仿生模式识别的方法和基于K近邻的方法做了对比,实验结果表明本文的方法克服了对未训练类型的人脸误识问题,提高了人脸识别系统的训练速度和正确识别率.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

HER2/neu基因在肿瘤中的过度表达使其成为许多肿瘤的标志分子。人肿瘤坏死因子(TNF-α)和肿瘤坏死因子相关的凋亡诱导配体(Trail)对肿瘤细胞的杀伤作用使其成为前景看好的抗肿瘤药物,对它们的细胞杀伤机制研究日渐深入。但临床研究发现HER2/neu过度表达的肿瘤细胞抵制TNF-α和Trail的肿瘤杀伤作用,因此经常产生耐药现象。为了增加过度表达HER2/neu的肿瘤细胞对TNF-a的敏感性和提高HER2/neu抗体的肿瘤杀伤效应,我们将抗HER2/neu人源化单链抗体scFvC6.5与人翔F-a融合,构建了免疫毒素scFvC6.5-TNF-α,完成了该重组蛋白在大肠杆菌中的表达,产率为800μg/L菌液。经过亲和层析和柱复性,融合蛋白的纯度达95%以上。ELISA试验表明scFvC6.5-TNF-a能够特异结合HER2/neu阳性卵巢癌细胞SKO从3和乳腺癌细胞MCF-7,而不结合HERZ/neu阴性的黑色素瘤细胞A-375。MTT试验表明scFvC6.5-TNF-a能够选择性的杀伤SKOV-3和MCF-7细胞,而不影响A-375细胞的生长。同时为了增加过度表达HER2/neu的肿瘤细胞对人可溶性肿瘤坏死因子相关的凋亡诱导配体(sTrail)的敏感性和提高HER2/neu抗体的肿瘤杀伤效应,我们构建了scFvC6.5与人sTrail的融合蛋白scFvC6.5-sTrail。重组子经酶切及测序证明序列正确后,在大肠杆菌BL21(DE3)中进行诱导表达。经SDS-PAGE及westem一blot鉴定,获得高水平包含体表达菌株,产率为700雌/L菌液。对表达产物进行变性、复性及纯化,SDS-PAGE结果显示纯度达95%以上。用ELISA法检测纯化后蛋白的结合活性表明融合蛋白scFvC6.5-sTrail能够特异结合HERZ/neu阳性卵巢癌细胞SKO从3、乳腺癌细胞McF-7和Trail敏感菌株MDA-MB-231,而不结合HER2/neu阴性和Trail受体阴性的黑色素瘤细胞A-375。MTT法检测其生物活性显示纯化后的scFvC6.5-sTrail蛋白对SKO从3、MCF-7、MDA-MB-231均具有细胞毒活性,并存在剂量依赖性,但对A-375细胞没有作用。细胞凋亡流式分析表明这两种免疫毒素对SKO从3靶细胞的杀伤作用是通过诱导细胞凋亡所致。提示这两种免疫毒素在抗肿瘤靶向治疗中具有潜在的应用价值。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Accurate and fast genotyping of single nucleotide polymorphisms (SNPs) is important in the human genome project. Here an automated fluorescent method that can rapidly and accurately genotype multiplex known SNPs was developed by using a homemade kit, which has lower cost but higher resolution than commercial kit. With this method, oncogene K-ras was investigated, four known SNPs of K-ras gene exon 1 in 31 coloerctal cancer patients were detected. Results indicate that mutations were present in 8(26%) of 31 patients, and most mutations were localized in codon 12. The presence of these mutations is thought to be a critical step and plays an important role in human colorectal carcinogenesisas. (C) 2003 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

HER2/neu基因在肿瘤中的过度表达使其成为许多肿瘤的标志分子.为了增加过度表达HER2/neu的肿瘤细胞对肿瘤坏死因子(TNF)的敏感性和提高HER2/neu抗体的肿瘤杀伤效应,将抗HER2/neu单链抗体C6.5与人肿瘤坏死因子hTNF-α融合,构建了scFvC6.5-hTNF-α融合蛋白,完成了重组蛋白在大肠杆菌中的表达,产率为400μg/L菌液.经过亲和层析和柱复性,融合蛋白的纯度达95%以上.ELISA试验表明,scFvC6.5-hTNF-α能够特异结合HER2/neu阳性卵巢癌细胞SKOV-3和乳腺癌细胞MCF-7,而不结合HER2/neu阴性的黑色素瘤细胞A375.MTT试验表明,scFvC6.5-hTNF-α能够选择性地杀伤SKOV-3和MCF-7细胞,而不影响A375细胞的生长.这种肿瘤细胞特异性杀伤作用提示该免疫毒素具有肿瘤靶向治疗的潜在应用价值.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Rhein, an anthraquinone derivative of rhubarb, inhibits the proliferation of various human cancer cells. In this paper, we focused on studying the effects of rhein on human hepatocelluar carcinoma BEL-7402 cells and further understanding the underlying molecular mechanism in an effort to make the potential development of rhein in the treatment of cancers. Using MTT assay and flow cytometry, we demonstrate a critical role of rhein in the suppression of BEL-7402 cell proliferation in a concentration- and time-dependent manner. The increase of apoptosis rate was observed after incubation of BEL-7402 cells with rhein at 50-200 mu M for 48 hours, and the cells exhibit typical apoptotic features including cellular morphological change and chromatin condensation. Moreover, rhein-induced cell cycle S-phase arrest. Additionally, after rhein treatment, expression levels of c-Myc gene were decreased, while those of caspase-3 gene were increased in a dose-dependent manner by using real-time PCR assay. The results demonstrate for the first time that cell cycle S-phase arrest is one of the mechanisms of rhein in inhibition of BEL-7402 cells. Rhein plays its role by inducing cell cycle arrest via downregulation of oncogene c-Myc and apoptosis through the caspase-dependent pathway. It is expected that rhein will be effective and useful as a new agent in hepatocelluar carcinoma treatment in the future.