We attempted to improve the activity of hTERT promoter by fusing the vascular endothelial growth factor （VEGF） enhancer. To determine the potential as cancer specific promoters, we measured the reporter gene transfe...We attempted to improve the activity of hTERT promoter by fusing the vascular endothelial growth factor （VEGF） enhancer. To determine the potential as cancer specific promoters, we measured the reporter gene transfection assay driven by the hTERT promoter and the VEGF enhancer in human cancer cells. We found that the hTERT promoter containing VEGF enhancer conferred strong expression of the reporter gene only in different cancer cell lines but not in normal human cells. Retrovirus vector expressing HSV-TK controlled by the hTERT promoter and the VEGF enhancer was constructed. A549 cells infected with LN-enh-hT-TK was significantly suppressed and induced to apoptosis more than those infected with LN-hT-TK. The apoptosis ratio ofA549 cell infected with two kinds of retrovirus cell with GCV in lower concentration is 20.94% and 50.7%. It suggested that there is significant differentiation between the assay groups. Our results demonstrated the possible application of hTERT promoter and the VEGF enhancer in targeted cancer gene therapy.展开更多
Human ribosomal DNA (hrDNA) target- ing vector (pHrn) is one of the human derived vectors, which was devised by our lab and has got patent authority. To investigate its effect on gene therapy for hepatocellular carcin...Human ribosomal DNA (hrDNA) target- ing vector (pHrn) is one of the human derived vectors, which was devised by our lab and has got patent authority. To investigate its effect on gene therapy for hepatocellular carcinoma, a double suicide fusion gene expression cassette, CDUPRT/GFP controlled by a synthetic CMV enhancer-enhanced hTERT promoter (CeTp) which was determined by luciferase assays was constructed in pHrn backbone, creating an expression vector pHr-CeTpCDUPRT/GFP. After transfer of plasmid to hepatocellular carcinoma cell line Bel7402 in vitro, the transfection efficiency reached 30%―50% by using flow cytometer. The expression of CDUPRT/GFP was detected by RT-PCR and Western Blotting. After the administra- tion of 5-FC, high performance liquid chromatography (HPLC) was applied to examine the level of 5-FU in supernatant, resulting in a concentration of 60.15 μg/mL. The Methylthiazolyl tetrazolium (MTT) assay was then utilized to investigate the antitumor effect of pHr-CeTpCDUPRT/GFP in Bel7402 cells, and rela- tive cell survival of 60%-35% was observed after 5-FC treatment. In vivo experiments, the nude mouse model of hepatocellular carcinoma was constructed and in situ gene therapy was performed. The results indicated the tumor growth of treatment group was obviously suppressed, and some even shrank, whenthe vectors and prodrugs were injected continuously. The expression of CDUPRT in tumor tissues was also identified by RT-PCR, and the concentration of 5-FU was 7.694 μg/mL in blood serum using HPLC detection. Then the pathological section of tumor tissues revealed significant tumor cell necrosis. All of these results provide important experiment evidences of the gene therapy for hepatocellular carcinoma with the utilization of our vectors.展开更多
目的:比较不同长度的hTERT启动子以及Survivin启动子在肺癌A549细胞中的启动活性,为肺癌靶向性基因治疗提供依据。方法:用PCR法扩增1084 bp hTERT启动子、980 bp Survivin启动子和红色荧光蛋白基因;在真核表达质粒pGL3-hTERT基础上分别...目的:比较不同长度的hTERT启动子以及Survivin启动子在肺癌A549细胞中的启动活性,为肺癌靶向性基因治疗提供依据。方法:用PCR法扩增1084 bp hTERT启动子、980 bp Survivin启动子和红色荧光蛋白基因;在真核表达质粒pGL3-hTERT基础上分别构建3种启动子调控的、以红色荧光蛋白CDS为目的基因的真核表达质粒pGL-H-RED、pGL-LH-RED和pGL-S-RED。将重组质粒用脂质体分别转染A549和MRC-5细胞,72h后用Imagepro-Plus6.0分析3种启动子在相同时间内启动红色荧光蛋白的表达水平。结果:重组质粒在A549细胞中观察到了红色荧光,在MRC-5细胞中无红色荧光。pGL-S-RED质粒在A549细胞中表达最强,pGL-LH-RED次之,pGL-H-RED最弱,3种质粒在A549细胞中的荧光强度(IOD)分别为201.17、171.70和136.34。结论:所克隆的hTERT启动子和Survivin启动子均表现出肿瘤特异性,其中Survivin启动子在肺癌A549细胞中具有最好的启动效应,可望开发成为肺癌靶向性基因治疗工具。展开更多
文摘We attempted to improve the activity of hTERT promoter by fusing the vascular endothelial growth factor （VEGF） enhancer. To determine the potential as cancer specific promoters, we measured the reporter gene transfection assay driven by the hTERT promoter and the VEGF enhancer in human cancer cells. We found that the hTERT promoter containing VEGF enhancer conferred strong expression of the reporter gene only in different cancer cell lines but not in normal human cells. Retrovirus vector expressing HSV-TK controlled by the hTERT promoter and the VEGF enhancer was constructed. A549 cells infected with LN-enh-hT-TK was significantly suppressed and induced to apoptosis more than those infected with LN-hT-TK. The apoptosis ratio ofA549 cell infected with two kinds of retrovirus cell with GCV in lower concentration is 20.94% and 50.7%. It suggested that there is significant differentiation between the assay groups. Our results demonstrated the possible application of hTERT promoter and the VEGF enhancer in targeted cancer gene therapy.
基金This work was supported by the National Natural Science Foundation of China(Grant No.30500302)Chinese 973 Projects(Grant No.2004CB518800)863 Projects(Grant No.2002AA227012).
文摘Human ribosomal DNA (hrDNA) target- ing vector (pHrn) is one of the human derived vectors, which was devised by our lab and has got patent authority. To investigate its effect on gene therapy for hepatocellular carcinoma, a double suicide fusion gene expression cassette, CDUPRT/GFP controlled by a synthetic CMV enhancer-enhanced hTERT promoter (CeTp) which was determined by luciferase assays was constructed in pHrn backbone, creating an expression vector pHr-CeTpCDUPRT/GFP. After transfer of plasmid to hepatocellular carcinoma cell line Bel7402 in vitro, the transfection efficiency reached 30%―50% by using flow cytometer. The expression of CDUPRT/GFP was detected by RT-PCR and Western Blotting. After the administra- tion of 5-FC, high performance liquid chromatography (HPLC) was applied to examine the level of 5-FU in supernatant, resulting in a concentration of 60.15 μg/mL. The Methylthiazolyl tetrazolium (MTT) assay was then utilized to investigate the antitumor effect of pHr-CeTpCDUPRT/GFP in Bel7402 cells, and rela- tive cell survival of 60%-35% was observed after 5-FC treatment. In vivo experiments, the nude mouse model of hepatocellular carcinoma was constructed and in situ gene therapy was performed. The results indicated the tumor growth of treatment group was obviously suppressed, and some even shrank, whenthe vectors and prodrugs were injected continuously. The expression of CDUPRT in tumor tissues was also identified by RT-PCR, and the concentration of 5-FU was 7.694 μg/mL in blood serum using HPLC detection. Then the pathological section of tumor tissues revealed significant tumor cell necrosis. All of these results provide important experiment evidences of the gene therapy for hepatocellular carcinoma with the utilization of our vectors.
文摘为了确定人端粒酶催化亚基 h TERT基因的启动子结构特征 ,采用 Panhandle PCR技术 ,从正常人外周血单核细胞基因组 DNA中扩增 h TERT基因 5′端上游旁侧序列 ,结果获得了 h TERT基因翻译起始位点上游 2 0 90 bp的基因组 DNA序列。序列分析表明 h TERT基因的启动子区域缺少典型真核启动子的核心元件 ( TATA box和 CAAT box) ,但含有多个已知转录因子蛋白结合的核心序列 ,如 E box及 Sp1核心序列。提示 h TERT基因的表达可能受特殊的转录因子调控 ,这些转录因子的激活可能与癌变细胞中 h
文摘目的:比较不同长度的hTERT启动子以及Survivin启动子在肺癌A549细胞中的启动活性,为肺癌靶向性基因治疗提供依据。方法:用PCR法扩增1084 bp hTERT启动子、980 bp Survivin启动子和红色荧光蛋白基因;在真核表达质粒pGL3-hTERT基础上分别构建3种启动子调控的、以红色荧光蛋白CDS为目的基因的真核表达质粒pGL-H-RED、pGL-LH-RED和pGL-S-RED。将重组质粒用脂质体分别转染A549和MRC-5细胞,72h后用Imagepro-Plus6.0分析3种启动子在相同时间内启动红色荧光蛋白的表达水平。结果:重组质粒在A549细胞中观察到了红色荧光,在MRC-5细胞中无红色荧光。pGL-S-RED质粒在A549细胞中表达最强,pGL-LH-RED次之,pGL-H-RED最弱,3种质粒在A549细胞中的荧光强度(IOD)分别为201.17、171.70和136.34。结论:所克隆的hTERT启动子和Survivin启动子均表现出肿瘤特异性,其中Survivin启动子在肺癌A549细胞中具有最好的启动效应,可望开发成为肺癌靶向性基因治疗工具。
