The initial study of ultrasound-targeted microbubble destruction enhanced gene delivery in tumor xenografts accompanied with polyethylenimine
- VernacularTitle:超声靶向微泡破坏联合聚乙烯亚胺增强裸鼠移植瘤基因输送的初步研究
- Author:
Zhiyi CHEN
;
Mingxing XIE
;
Xinfang WANG
;
Qing Lü
- Publication Type:Journal Article
- Keywords:
Ultrasonography;
Microbubbles;
Gene transfer techniques;
Polyethyleneimine
- From:
Chinese Journal of Ultrasonography
2008;17(12):1082-1087
- CountryChina
- Language:Chinese
-
Abstract:
Objective To determine whether it could enhance gene delivery and tumor transfection in vivo by combination of ultrasound-targeted microbubble destruction(UTMD)with polyethylenimine(PEI)in tumor xenografts.Methods Two different reporter plasmid[lueiferase(pCMV-LUC)and red fluorescent protein(RFP)]were incubated with PEI to prepare cationic compound(PEI/DNA)in various nitrogen:phosphate ratios(N/P ratios,nmol of nitrogen in the PEI/nmol of phosphate in DNA).Formation of PEI/DNA complexes were confirmed by the gel retardation assay.Human cervical carcinoma(Hela)tumors were planted subcutaneously in both flanks of female nude mice.Tumor-bearing mice were administered by tail vein with PBS,plasmid,plasmid and Sono Vue microbubble,PEI/DNA and Sono Vue microbubble.One tumor was exposed to ultrasound irradiation (3 MHz,2 W/cm2,2 min exposure,duty cycle 20%),while the other served as control.The feasibility of targeted delivery and tissue specificity facilitated by UTMD and PEI was investigated.The mice were sacrificed 3 days after ultrasound exposure.Tissue specimens were viewed with microscopy to determine the presence of RFP expression.The efficiencies of luciferase transgene expression were determined.Histology analysis was detected.Results Electrophoresis experiment revealed that PEI was mixed with plasmid to condense DNA efficiently.The application of UTMD significantly increases the tissue transfection in vivo compared to plasmid alone.RFP expression was present in all sections of tumors that received ultrasound exposure but not in control tumors.Results of luciferase activity showed that the expression of luciferase was to be 14 times greater in ultrasound-exposed tumors(P＜0.01).More importantly,the increase in transgene expresgion was related to UTMD with the presence of PEI dramatically.At least 10-fold increase of luciferase gene transfer was obtained in irradiated tumors compared to non-irradiated controls(P＜0.01),111-fold increase compared to UTMD alone(P＜0.01).There was not significantly gene expression in other organs or tissues regardless of US exposure(P＞0.05).No tissue damage was seen histologically.Conclusions The combination of UTMD with PEI can enhance targeted delivery and expression of reporter gene to tumors at intravenous administration.It is a promising new and safe method for gene delivery in vivo.
