Objective: To investigate the feasibility of marking the human tumor cells with enhanced green fluorescent protein (EGFP) in vitro. Methods: The retroviral vector LGSN encoding EGFP was constructed and three human tum...Objective: To investigate the feasibility of marking the human tumor cells with enhanced green fluorescent protein (EGFP) in vitro. Methods: The retroviral vector LGSN encoding EGFP was constructed and three human tumor cell lines were infected with LGSN amphotropic virus. Tumor cell lines that stably express EGFP were selected with G418. The integration and expression of EGFP gene were analyzed by polymerase chain reaction, and flow cytometry (FCM). Results: After gene transfection and ping-pong transduction, amphotropic producer line Am12/LGSN was generated with a stable green fluorescence signal readily detectable by FCM in up to 97% of examined cells. The viral titer in the supernatants was up to 8.2×105CFU/ml. After transduction and selection, G418-resistant leukemia K562, mammary carcinoma MCF-7, and bladder cancer 5637 cells were developed, in which the integration of both EGFP and neomycin resistance gene was confirmed by DNA amplification. In comparison with uninfected cells, FCM analysis revealed EGFP expression in up to 90% (range 85.5%–90.0%) of tumor cells containing LGSN provirus. Conclusion: The retroviral vector LGSN can effectively mark the human tumor cells with a stably EGFP expression which may be in studying tumor growth, metastasis and angiogenesis.展开更多
Telomerase activity was found to be high in various human cancers, but absent in most normal tissues. Its expression pattern made it a novel target for antitumor agents. Several strategies against telomerase were pres...Telomerase activity was found to be high in various human cancers, but absent in most normal tissues. Its expression pattern made it a novel target for antitumor agents. Several strategies against telomerase were presented in this review. Targeting the telomerase RNA component by oligonucleotide/ribozyme was considered to be one of the most hopeful approaches. Some progresses were made in this area, such as the use of PANs and 2–5A antisense compounds. The relationships among telomerase activity and cell differentiation, signal transduction, oncogene, tumor suppressor gene as well as cell cycle modulation also provided a series of valuable ideas in designing anti-telomerase drugs for cancer therapy. In conclusion, although there is still a long way in understanding the mechanism and regulation of telomerase, the advance of studies on telomerase has allowed the development of numerous strategies for the treatment of cancer.展开更多
为探讨腺病毒介导肿瘤坏死因子 - α(TNF- α)基因转染诱导树突细胞 (DCs)趋化因子受体差异性表达 ,分别用 10 0 MOI的 Ad V- TNF- α和 Ad V- p L p A (无外源基因插入 )感染小鼠树突细胞 (m DCs) ,经流式细胞仪检测细胞表型变化 ,RNA...为探讨腺病毒介导肿瘤坏死因子 - α(TNF- α)基因转染诱导树突细胞 (DCs)趋化因子受体差异性表达 ,分别用 10 0 MOI的 Ad V- TNF- α和 Ad V- p L p A (无外源基因插入 )感染小鼠树突细胞 (m DCs) ,经流式细胞仪检测细胞表型变化 ,RNA酶保护实验检测其趋化因子受体表达 ,体内、体外细胞趋化试验分析比较其迁移差异。发现 Ad V- TNF-α感染 m DCs后 CD11b、CD40、CD86 ,ICAM- 1以及 CCR7受体表达较对照组明显增高 ,CCR2受体表达量却下调 ;体外细胞趋化试验表明 DCTNF -α对 MIP- 3β(CCR7配体 )迁移应答增强 ,体内细胞趋化试验显示 DCTNF-α淋巴结趋化迁移效率较空白对照组和 Ad V- p L p A感染组分别增高 7倍和 3倍。提示 :Ad V- TNF- α感染促使 m DCs成熟 。展开更多
文摘Objective: To investigate the feasibility of marking the human tumor cells with enhanced green fluorescent protein (EGFP) in vitro. Methods: The retroviral vector LGSN encoding EGFP was constructed and three human tumor cell lines were infected with LGSN amphotropic virus. Tumor cell lines that stably express EGFP were selected with G418. The integration and expression of EGFP gene were analyzed by polymerase chain reaction, and flow cytometry (FCM). Results: After gene transfection and ping-pong transduction, amphotropic producer line Am12/LGSN was generated with a stable green fluorescence signal readily detectable by FCM in up to 97% of examined cells. The viral titer in the supernatants was up to 8.2×105CFU/ml. After transduction and selection, G418-resistant leukemia K562, mammary carcinoma MCF-7, and bladder cancer 5637 cells were developed, in which the integration of both EGFP and neomycin resistance gene was confirmed by DNA amplification. In comparison with uninfected cells, FCM analysis revealed EGFP expression in up to 90% (range 85.5%–90.0%) of tumor cells containing LGSN provirus. Conclusion: The retroviral vector LGSN can effectively mark the human tumor cells with a stably EGFP expression which may be in studying tumor growth, metastasis and angiogenesis.
文摘Telomerase activity was found to be high in various human cancers, but absent in most normal tissues. Its expression pattern made it a novel target for antitumor agents. Several strategies against telomerase were presented in this review. Targeting the telomerase RNA component by oligonucleotide/ribozyme was considered to be one of the most hopeful approaches. Some progresses were made in this area, such as the use of PANs and 2–5A antisense compounds. The relationships among telomerase activity and cell differentiation, signal transduction, oncogene, tumor suppressor gene as well as cell cycle modulation also provided a series of valuable ideas in designing anti-telomerase drugs for cancer therapy. In conclusion, although there is still a long way in understanding the mechanism and regulation of telomerase, the advance of studies on telomerase has allowed the development of numerous strategies for the treatment of cancer.
文摘目的:探讨通过增强树突状细胞(dendritic cells,DC)与T细胞的相互作用来进一步增强DC介导的抗肿瘤免疫效果。方法:体外培养的小鼠骨髓DC体外经携带人MIP-1β基因的重组腺病毒(adenovirus expressing human macrophoge irrflam—matory protein-1 beta,AdhMIP-1β)转染后(MIP-1β-DC),用小鼠CT26结肠腺癌细胞相关抗原冲击致敏,然后免疫正常同系小鼠,观察其体内诱导的细胞毒性T淋巴细胞(cytotoxic T lymphocyte,CTL)的保护性免疫反应;通过体内阻断试验探讨免疫细胞亚群及免疫分子在DC诱导抗肿瘤免疫应答中的作用。结果:经抗原致敏的MIP-1β—DC能更有效地诱导特异CTL活性,能使免疫动物产生更有效的免疫保护作用,抵抗肿瘤细胞的攻击。通过对其抗肿瘤免疫机理的分析发现,CD4+、CD8+T细胞共同参与了经抗原致敏的:MIP-1β—DC介导的抗肿瘤免疫反应,是主要的抗瘤效应细胞,NK细胞作用不明显。结论:通过基因修饰增强树突状细胞对T细胞的体内趋化活性,能更有效地诱导抗肿瘤免疫反应,为树突状细胞介导的肿瘤免疫基因治疗开辟了新的途径。
文摘为探讨腺病毒介导肿瘤坏死因子 - α(TNF- α)基因转染诱导树突细胞 (DCs)趋化因子受体差异性表达 ,分别用 10 0 MOI的 Ad V- TNF- α和 Ad V- p L p A (无外源基因插入 )感染小鼠树突细胞 (m DCs) ,经流式细胞仪检测细胞表型变化 ,RNA酶保护实验检测其趋化因子受体表达 ,体内、体外细胞趋化试验分析比较其迁移差异。发现 Ad V- TNF-α感染 m DCs后 CD11b、CD40、CD86 ,ICAM- 1以及 CCR7受体表达较对照组明显增高 ,CCR2受体表达量却下调 ;体外细胞趋化试验表明 DCTNF -α对 MIP- 3β(CCR7配体 )迁移应答增强 ,体内细胞趋化试验显示 DCTNF-α淋巴结趋化迁移效率较空白对照组和 Ad V- p L p A感染组分别增高 7倍和 3倍。提示 :Ad V- TNF- α感染促使 m DCs成熟 。
