5/35嵌合型溶瘤腺病毒SG635对肝癌细胞的抑制作用

Inhibitory effect of 5/35 chimeric oncolytic adenovirus SG635 on hepatocarcinoma cells

目的:研究5/35嵌合型溶瘤腺病毒SG635在体外对肝癌HepG2和SMMC-7721细胞的特异性杀伤作用。方法:将SG600载体中5型腺病毒(Ad5)纤毛蛋白的knob和shaft结构域替换为35型腺病毒(Ad35)纤毛蛋白的相应结构域,构建成5/35嵌合型溶瘤腺病毒SG635。流式细胞术检测5/35嵌合型腺病毒Ad5/35-EGFP对HepG2和SMMC-7721细胞的感染效率,体外病毒增殖实验观察溶瘤腺病毒SG635的增殖能力,Western blotting检测SG635感染后肝癌细胞中E1A蛋白的表达,CCK-8实验检测SG635对肝癌HepG2和SMMC-7721细胞的杀伤作用。结果:在肝癌HepG2和SMMC-7721细胞中,Ad5/35-EGFP的感染效率明显强于5型腺病毒Ad5-EGFP;5/35嵌合型溶瘤腺病毒SG635在HepG2和SMMC-7721细胞中72 h的增殖倍数高于5型溶瘤腺病毒SG600(15 848.93vs6 309.57,6 309.57vs5 011.87,均P<0.01),而在人正常成纤维细胞BJ中几乎不增殖。SG635感染后,HepG2和SMMC-7721细胞中E1A蛋白表达高于SG600感染,在BJ中则无E1A表达。在一定MOI范围内,SG635对于HepG2细胞和SMMC-7721细胞的杀伤作用逐渐增强,且杀伤率明显强于SG600(MOI为1时,90%vs60%;MOI为10时,90%vs50%),对BJ无杀伤作用。结论:5/35嵌合型溶瘤腺病毒SG635能够高效感染并特异性杀伤肝癌细胞,具有较好的靶向性和安全性。

Objective：To investigate the specific cytotoxicity effect of 5/35 chimeric oncolytic adenovirus SG635 on hepatocellular carcinoma HepG2 and SMMC-7721 cells.Methods： The knob and shaft domains of type 5 adenovirus（Ad5） in SG600 plasmid were replaced by the domains of type 35 adenovirus（Ad35）,and chimeric oncolytic adenovirus Ad5/35 was established.Flow cytometry was used to examine the infection efficiency of chimeric adenovirus Ad5/35（Ad5/35-EGFP） in HepG2 and SMMC-7721 cells;replication assay was used to evaluate the replication of oncolytic adenovirus SG635;Western blotting analysis was used to examine the expression of E1A in cells after SG635 infection;and Kit-8 assay was used to assess the cytotoxicity of SG635 and SG600 on HepG2 and SMMC-7721 cells.Results： The infection efficiency of Ad5/35-EGFP in HepG2 and SMMC-7721 cells was obviously enhanced compared with Ad5-EGFP.The replication activity of SG635 in HepG2 and SMMC-7721 cells was higher than that of SG600 72 h after infection（15 848.93,6 309.57 vs 6 309.57,5 011.87,P〈0.01）,but SG635 did not replicate in normal BJ cells.Moreover,SG635 induced a higher expression of E1A protein in HepG2 and SMMC-7721 cells than SG600,but did not induce E1A expression in normal BJ cells.At a certain MOI,SG635 showed increasing cytotoxicity on HepG2（MOI=1,90% vs 60%） and SMMC-7721（MOI=10,90% vs 50%） cells,and the cytotoxicity was stronger than SG600,without causing significant cytotoxicity on normal BJ cells.Conclusion： The 5/35 chimeric oncolytic adenovirus SG635 can effectively infect and specifically kill hepatocarcinoma cells with satisfactory safety and specificity.