摘要
目的 评价磁性脂质体作为基因载体在外加磁场的介导下发夹RNA （shRNA）对体内外人非小细胞肺癌生长的抑制作用和评价外加磁场对于体外磁转染效率的影响.方法 构建表达绿色荧光蛋白（GFP）和肺癌胰岛素样生长因子-1受体（IGF-1R）基因的shRNA的质粒pGFPshIGF-1R,由磁性氧化铁纳米颗粒CombiMAG和脂质体lipofectamine2000组成磁性脂质体,将pGFPshIGF-1R转染进肺癌A549细胞,此过程被称为磁转染,通过外加不同强度和不同作用时间的磁场,评价磁场对磁转染效率的影响；将质粒pGFPshIGF-1R分别通过磁转染,脂质体转染传递到A549细胞中,通过Western印迹评价两种转染方法下A549细胞IGF-1R蛋白过表达下调情况；在荷瘤鼠肺癌模型中静脉注射质粒pGFPshIGF-1R与磁性脂质体或单纯脂质体的复合物,比较两者体内抑瘤效果.结果 外加磁场的作用时间和磁场强度可影响磁转染效率.体外脂质体转染和磁转染的shRNA都明显的抑制了A549细胞IGF-1R的蛋白过表达,干扰率分别达56.1％±6.0％和85.1±3.0％（P＜0.01）.体内脂质体转染和磁转染的shRNA都明显的抑制了荷瘤鼠皮下移植瘤的生长,对照组、体内脂质体转染组和磁转染组裸鼠移植瘤瘤重分别为（0.46±0.12）、（0.27 ±0.05）、（0.16±0.04）g,脂质体转染组和磁转染组的抑瘤率分别为41.3％ （P ＜0.01）和65.2％ （P ＜0.01）.结论 以磁性脂质体作为基因载体的磁转染可能会成为靶向肺癌治疗的重要的转染方法,其转染效率受到外部磁场的影响.
Objective To evaluate the inhibition of shRNA mediated by magnetic liposome in the growth of non-small cell lung cancer （NSCLC） under the interference of magnetic field in vitro and in vivo andexplore the effects of magntic field on the efficiency of magnetofection. Methods The plasmid of pGFPshIGF-1R was constructed for expressing GFP and shRNA against IGF-1R. CombiMAG as superparamagnetic iron oxide nanoparticles （SPIONs） and Lipofectamine2000 as cationic liposome comprised the magnetic liposome.pGFPshIGF-1R was transferred into A549 cells by magnetofection under a series of interaction durations and intensity of external magnetic fields.pGFPshIGF-1R was delivered into A549 cells in vitro and injected intravenously into the tumor-bearing mice every 48 h for four doses in vivo by way of lipofection or magnetofection. The magnetofection efficiency was analyzed by cytometry and the potency of IGF-1R knockdown by Western blot.At Week 3 after the 4th injection,the mice were sacrificed and the tumors removed and weighed.The tumor inhibition rate was calculated.Results The interaction durations and intensity of magnetic field could influence the magnetofection efficiency.In vitro,IGF-1R specific-shRNA transfected by lipofection inhibited IGF-1R protein by 56.1% ± 6.0% and by liposomal magnetofection by 85.1% ± 3.0%. In vivo, pGFPshIGF-1R delivered by both lipofection and magnetofection significantly inhibited the tumor growth by 41.3% （ P 〈 0.01 ） and 65.2% （ P 〈 0.01 ）.Conclusions Based on magnetic liposome as gene vectors,magnetofection may become a promising targeted therapy for lung cancer.And the transfection efficiency is influenced by magnetic field.
出处
《中华医学杂志》
CAS
CSCD
北大核心
2012年第5期341-344,共4页
National Medical Journal of China
关键词
磁铁矿纳米颗粒
脂质体
癌
非小细胞肺
RNA干扰
Magnetite nanoparticles
Liposomes
Carcinoma, non-small-cell lung
RNA interference
