双靶向溶瘤腺病毒MD55对肿瘤细胞与正常细胞的杀伤作用比较

Selective Cytotoxic Effect of Dual Tumor-targeting Oncolytic Adenovirus MD55 on Tumor and Normal Cells in Vitro

应用分子克隆和同源重组技术构建双靶向溶瘤腺病毒MD55。分析MD55病毒在细胞中的复制能力,并用MTT和结晶紫方法检测MD55对肿瘤细胞和正常细胞生长的影响,West-ern印迹检测病毒感染后细胞中E1A蛋白和多聚ADP核糖聚合酶(PARP)片断的表达。结果显示,MD55能在MN/CA9阳性的肿瘤细胞SW620和OSRC-2中特异性表达E1A蛋白,并且在这些细胞中的复制能力和对这些细胞的杀伤性与对照病毒ZD55基本相同,而其在正常细胞中的复制能力很弱,对正常细胞的伤害很小;同时MD55可诱导肿瘤细胞SW620和OSRC-2的凋亡,而对正常细胞的凋亡无影响。实验结果表明双靶向溶瘤腺病毒MD55靶向性和安全性比单靶向病毒ZD55更高,有望成为一种很好的肿瘤靶向基因-病毒治疗载体。

A dual tumor-targeting oncolytic adenovirus （MD55） was constructed by molecular cloning and homologous recombination. The replication ability of MD55 virus in different cell lines was analyzed. Cytotoxic effects of the MD55 virus on tumor and normal cell lines were detected by crystal violet staining and MTT assay. After infected by virus, the expressions of E1A and PARP proteins in different cell lines were analyzed by Western blot. Results showed that MD55 displayed specific E1A expression in MN/CA9- positive cancer cell lines SW620 and OSRC-2. The proliferation ability and cytotoxic effect of MD55 virus became very low in normal cells, but almost equal to that of ZD55 in MN/CA9-positive cells. MD55 might induce apoptosis in SW620 and OSRC-2 cells but not in normal cells. The results suggest that MD55 has specific cytotoxicity in MN/CA9-positive cancer cells and more safety for normal cells in comparison with ZD55. It may be a good vector for cancer gene-virus therapy.