γ射线联合HSV-tk/GCV基因治疗系统抗肿瘤体外实验研究  

Cytocidal efficacy of γ-rays combined with HSV-tk/GCV gene therapy on Lewis lung carcinoma cells in vitro

作　　者：陈治国[1] 杨业鹏[1] 周梅[1] 占晓海[1] 沈剑 沈磊[1] 李五岭[1] 王新娟[2] 

机构地区：[1]北京大学基础医学院放射医学教研室,100083 [2]北京大学生物化学与分子生物学系,100083

出　　处：《中华放射医学与防护杂志》2005年第6期509-513,共5页Chinese Journal of Radiological Medicine and Protection

基　　金：国家自然科学基金资助项目(30470523)

摘　　要：目的研究γ射线与人单纯疱疹病毒胸苷激酶(HSV-tk)/丙氧鸟苷(GCV)基因治疗系统联合应用对Lewis肺癌细胞的杀伤作用及其可能机制。方法以脂质体介导法将含HSV-tk基因的真核表达质粒体外转染小鼠Lewis肺癌细胞,建立稳定表达的细胞株;RT-PCR检测细胞tk基因表达;Hoechst33258/PI荧光活染、流式细胞术检测γ射线与HSV-tk/GCV系统单独及联合作用下的细胞凋亡;集落形成法检测细胞存活曲线,反映放射敏感性变化;同时检测旁观者效应及γ射线对该效应的影响。结果HSV-tk/GCV系统对转染基因的Lewis细胞(Lewis-Hytk细胞)具有选择性杀伤作用。γ射线与HSV-tk/GCV系统联合应用可使Lewis-Hytk细胞的凋亡和坏死率显著高于二者单独作用之和。0.1μg/ml GCV可使Lewis-Hytk细胞的放射敏感性明显增高(SER=1.47)。γ射线可增强HSV-tk/GCV系统的旁观者效应,二者联合作用后的Lewis-Hytk细胞的培养液对未处理过的Lewis细胞具有杀伤作用。结论γ射线与HSV-tk/GCV系统联合应用对Lewis肺癌细胞具有协同杀伤效应。γ射线增强HSV-tk/GCV系统的旁观者效应可能是其协同效应产生的机制之一。Objective To observe cytocidal efficacy of γ-rays combined with HSV-tk/GCV gene therapy on murine Lewis lung carcinoma cells in vitro and to explore the mechanism of the combined effects. Methods HSV-tk gene packaged with Lipofectin was stably transfected into Lewis lung carcinoma cells. HSV-tk mRNA expression was detected by reverse transcription polymerase chain reaction （RT-PCR）. Hoechst/PI vital staining and flow cytometry were used to measure apoptosis induced by the individual and the combined treatment of γ-rays and HSV-tk/GCV system. Cell survival curves were determined by colony formation method to evaluate changes of radiosensitivity of the cells. Moreover, bystander effect of the HSV-tk/GCV system and influence of γ irradiation on the bystander effect were detected. Results The HSV-tk/GCV system showed a selective cytocidal effect on the Lewis cells transfected with HSV-tk gene （Lewis-Hytk cells） . The apoptosis rate and necrosis rate of the cells treated by combined modality was significantly higher than the sum of those of the cells treated separately by these two individual modalities. A dose of 0.1 μg/ml GCV could obviously raise the radiosensitivity of Lewis-Hytk cells （SER = 1.47）. It was also noted that γ-rays could enhance the bystander effect of HSV-tk/GCV system and the medium from cultured Lewis-Hytk cells treated by combined modality showed a clear cell-killing effect on untreated Lewis cells. Conclusions γ-rays combined with HSV-tkGCV system can produce synergic cell-kithng effects on Lewis lung carcinoma cells. γ irradiation can enhance the bystander effect of HSV-tkGCV system, which may be one of the mechanisms that results in the synergism.

关 键 词：Γ射线 人单纯疱疹病毒胸苷激酶 基因治疗 LEWIS肺癌细胞 旁观者效应 

分 类 号：R73-3[医药卫生—肿瘤]