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Abstract
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@#Objective:To investigate the specific killing effect of magnetic nanoparticles Fe3O4@PEI induced targeted suicide gene therapycombinedwithmagneticfluidhyperthermiaonhepatomaxenograft.
METHODS:Thesuicidegenetargetinghepatomap[HRE]AFP-HSVTK and tumor cell imaging reporter gene vector p[HRE]AFP-Luc were constructed by sub-cloning gene recombination method, and tested by restriction endonuclease gel electrophoresis. Fe3O4 nano-particles were prepared by co-precipitation method and modified by Polyethyleneimine (PEI) to obtain the magnetic nano-particles Fe3O4@PEI,which could be used as carrier for tumor gene therapy and a medium for magnetic fluid hyperthermia treatment; and the characterization of Fe3O4@PEI was identified by transmission electron microscopy, particle size analyzer and Fourier transform infrared spectroscopy. The reporter genes p[HRE]AFP-Luc were delivered into the nude mice bearing xenografts via tail vein by Fe3O4@PEI, then the bioluminescence signals of mice were observed in an IVIS system.After the treatment of p[HRE]AFP-HSVTK/Fe3O4@PEI, the tumor cell inhibition rate was examined by MTT assay, the cell apoptosis was tested by Flow cytometry, the in vivo tumor development rate and tumor inhibition rate was tested by animal experiment, and the sub-cellular construction of tumor cells was observed by Transmission electron microscopy.
RESULTS: Nano-particles Fe3O4@PEI and recombinant vectors p[HRE]AFP-HSVTK and p[HRE]AFP-Luc were successfully constructed; after tale vein injection, image signals were detected only in tumor tissues via IVIS system, but no obvious pathologic damage in other major organs. In the in vitro cell killing test, the cell proliferation inhibition rate and the cell apoptosis rate in combination group was higher than that in hyperthermia treatment group and gene treatment group [inhibition rate: (76.02±7.33)% vs (42.31±4.28)%， (47.76±4.81)%, all P<0.05; apoptosis rate: (34.05±3.41)% vs (14.41±1.55)%， (11.64±1.20)%， all P<0.01]. The in vivo treatment showed that tumor volume development significantly slowed-down and even decreased in combination treatment group, and the tumor mass were significantly smaller than those of the single treatment groups (all P<0.05); and the tumor cell sub- cellular structure showed obvious apoptotic morphology.
CONCLUSION: the suicide gene p [HRE]AFP-HSVTK has specifickillingeffecton hepatomacells,Fe3O4@PEI can be used as effectivegene treatmentcarrierand mediaof magnetic heperthermia treatment; Fe3O4@PEI mediated target treatment combined with magnetic fluid hyperthermia treatment could specificallyinhibitthehepatomaxenograft.
Language: zh |