摘要
目的研究叶酸受体为靶向的脂质体包裹MYCN基因小干扰性RNA在神经母细胞瘤裸鼠骨髓、骨转移模型中的靶向性及治疗作用。方法 16只成功建立神经母细胞瘤骨髓、骨转移模型的裸鼠,将其随机分为靶向性研究组(4只)和疗效性研究组(12只)。靶向性研究组裸鼠静脉给予CY3荧光标记叶酸脂质体包裹的MYCN siRNA,荧光显微镜检测CY3在体内瘤组织及重要器官的荧光强度。疗效性研究组12只裸鼠随机分MYCN siRNA组和无关siRNA组,静脉分别给予叶酸脂质体包裹的MYCN siRNA与叶酸脂质体包裹的无关siRNA,采用荧光定量PCR检测肿瘤组织MYCN mRNA表达,原位细胞凋亡检测法(TUNEL)观察肿瘤细胞凋亡数。结果 CY3荧光标记的叶酸脂质体MYCN siRNA给药8 h后,荧光主要分布在肿瘤组织内,MYCN siRNA组瘤组织中MYCN mRNA的表达量明显较无关siRNA组降低(P<0.05),MYCN siRNA组凋亡细胞数量高于无关siRNA组(P<0.05)。结论①叶酸脂质体MYCN siRNA经静脉给药后主要靶向瘤组织,叶酸脂质体是肿瘤基因治疗的有效载体;②叶酸脂质体MYCNsiRNA在体内显著下调肿瘤MYCN mRNA的表达,促进肿瘤细胞凋亡,有望成为神经母细胞瘤治疗的新药物。
Objective To study the targeted efficacy and therapeutic effects of folate liposome entrapped MYCN siRNA in xenograft mouse model with neuroblastoma bone marrow and bone metastasis.Methods Mouse model with bone and bone marrow metastasric neuroblastoma were established and sixteen mouses were randomly assigned to two groups： targeting efficacy study group and antitumor efficacy study group.4 mouses in targeting efficacy study group were intravenous injected of folate liposome entrapped MYCN gene siRNA,which was labeled with Cy3 fluorescence,distribution of MYCN siRNA in tumor and normal tissue was detected by fluorescence microscope.12 mouses in antitumor efficacy study group were divided into two groups,folate liposome entrapped MYCN gene siRNA and folate liposome entrapped non-sense siRNA were administrated by intravenous injection respectively.The level of MYCN mRNA expression in the tumor was quantified by quantitative reverse transcription polymerase chain reaction（RT-PCR）,tumor cell apoptosis was observed by TdT-mediated dUTP nick end labeling（TUNEL）.Results CY3 fluorescent was concentrated in tumor tissue 8 hours after administered and the level of MYCN mRNA expression was significantly knock-downed compared to control MYCN siRNA.A significant increase of positive cells was observed at MYCN siRNA group compared with those at non-sense siRNA group.Conclusion MYCN siRNA is highly concentrated in neuroblastoma tissue via folate liposome entrapment after intravenous injection.It significantly reduces MYCN mRNA expression and inhibits neuroblastoma cell apoptosis in nude mouse,these findings suggest that FR-targeted liposome is an effective vehicle for tumor-targeted siRNA delivery and the liposome entrapped folate FT-targeted MYCN siRNA is potential agent for neuroblastoma therapy.
出处
《中国医药导报》
CAS
2012年第16期22-24,共3页
China Medical Herald
基金
国家高科技研究发展计划(863计划)课题(课题名称:RNA干扰等新型的基因治疗研究
课题编号:2010AA020804)
