中文摘要：

目的：构建缺失E1A区24bp，由端粒酶反转录酶基因启动子和缺氧基因启动子调控的增殖腺病毒SG600-IL24，研究人白细胞介素24（interleukin 24，IL24）在肝癌细胞内的表达水平和SG600-IL24的增殖情况及其对肝癌细胞的杀伤作用。方法：利用DNA克隆和重组技术，构建SG600-IL24。ELISA检测IL24在肝癌细胞SMMC-7721、BEL4404和正常成纤维细胞BJ内的表达。半数组织培养感染剂量（50％ tissue culture infectious dose，TCID50）法检测SG600-IL24在3种细胞内48和96h的增殖情况。MTT法和细胞病理效应（cytopathic effect，CPE）染色法检测SG600-IL24在不同MOI值对3种细胞的杀伤作用。结果：IL24在SMMC-7721和BEL-7404细胞内高表达而在BJ细胞内低表达。感染48和96h后，SG600-IL24在SMMC-7721、BEL-7404和BJ细胞内分别增殖794和7940倍、622和7810倍、20和200倍。MTT结果显示，杀伤50％和90％的SMMC-7721、BEL-7404和BJ细胞所需SG600-IL24的MOI值分别为0．3和5，3和20，50和150。CPE染色显示，SG600-IL24对肝癌细胞SMMC-7721和BEL-7404有明显杀伤作用，而对BJ细胞无明显影响，并且该病毒的杀伤能力比增殖腺病毒ZD55-IL24和非增殖腺病毒Ad-IL24强。结论：SG600-IL24高效感染肝癌细胞SMMC-7721和BEL-7404后，病毒增殖活跃，IL24的表达量显著升高。SG600-IL24对此2种肝癌细胞有良好的特异性杀伤作用，而对正常细胞没有明显影响，为应用该病毒治疗肝癌的体内研究建立了基础。

英文摘要：

Objective： To construct an E1A-deleted 24-bp triple regulated replicative adenovirus vector SG600/interleukin24 （IL24）, which was driven by both hTERT promoter and HRE promoter. The level of IL24 in liver cancer cells was determined and the replication capacity of SG600/IL24 and its killing effects on liver cancer cells were observed. Methods： SG600-IL-24 vector was constructed using DNA cloning and recombination techniques. The IL24 gene expression in liver cancer cell lines SMMC-7721 and BEL- 7404 and normal cell line BJ was detected by ELISA assay. The replications of SG600/IL-24 in different cell lines were determined by evaluating TCID50 （50% tissue culture infectious dose） at 48 and 96 h. In vitro cell-killing effects of SG600/IL24 on the three liver cancer cell lines were analyzed by MTT assay and CPE （cytopathic effect） staining method at different MOI values. Results： IL24 was over-expressed in both SMMC-7721 and BEL-7404 cells but was weakly expressed in BJ cells. At 48 and 96 h post infection the replication of SG600/IL-24 were 794 and 7940 folds in SMMC-7721 cells; 622 and 7 810 folds in BEL-7404 cells; 20 and 200 folds in BJ cells. MTT assay showed that the MOI values of SG600/IL24 for killing 50% and 90% cells were 0.3 and 5 for SMMC-7721 cells; 3 and 20 for BEL-7404 cells; 50 and 150 for BJ cells. CPE staining demonstrated that SG600/IL24 had significant killing effects on both liver cancer cells SMMC-7721 and BEL-7404 but had no significant influence on BJ cells. The cell-killing capability of SG600/IL24 was superior than that of replicative adenovirus ZD55/IL24 and non replicative adenovirus Ad-IL24. Conclusion： After SMMC-7721 and BEL- 7404 liver cancer cells are infected with SG600/IL24 at high efficiency, the virus replication is active and the expression of IL24 increases greatly. SG600/IL24 has specific cell-killing effects on the two liver cancer cell lines but has no significant influence on normal cells. This study provides a basis for further investigating the effect