Empirical study of hepatocellular carcinoma's gene therapy using hTERTp-TK/GCV in HepG2 which was mediated by chitosan nanoparticles vehicles

Abstract

Objective To compare the transfection efficiency of galactosylated chitosan nanoparticle vehicle with chitosan nanoparticles vehicle,and observe the therapeutic effect of pGL3-hTERTp-TK on HCC cell line HepG2. Methods Preparing the chitosan and galaetosylated chitosan. Constructing the pGL3-hTERTp-TK plasmid and the Ch/DNA and GC/DNA complexes.Transfecting the HepG2 and the normal hepatic cell L-02 with chitosan/DNA and galactosylated chitosan/DNA complexs.Detecting the fluorescence and the expression of luciferase gene using the fluorescent microscope and the scintillation counter.Detecting the cell growth and apoptosis through the Caspase-3 and the flow cytometry. Results Two clear straps appeared in the agarose gel.The locations were 300 bp and 1100 bp.The relative lueiferase activity of pGL3-hTERTp-Luc+mediated by galactosylated chitosan was powerful than which of pGL3-hTERTp-Luc+mediated by chitosan in HepG2 by the scintillation counter.However,the relative luciferase activity was very weak in L-02.The same results were observed by fluorescent microscope.When the concertration of the GCV was 10 μg/ml(t=51.40,P=0.000),the HepG2 cell inhibition which was transfected by GC-pGL3-hTERTp-TK was obviously different from the L-02 cell inhibition which was transfected by GC-pGL3-hTERTp-TK in the statistics.The significant apoptotic rate was 65.28%in HepG2 which was transfected with GC/DNA,whereas it was only 10.80% in L-02. The significant apoptotic rate in HepG2 which was transfected with GC/DNA was very higher than the other groups (LSD, P ＜0.05). The significant apoptotic rate (10.80%) in L-02 which was transfected with GC/DNA was very higher than the group which was Ch-pGL3-control (LSD, P =0.000). The average fluorescence intensity of the HepG2 which is transfected by the Ch-pGL3-hTERTp-TK was 168.02± 3.68. The average fluorescence intensity of the HepG2 which is transfected by the GC-pGL3-hTERTp-TK was 204.45 ±3.45. The two groups had a significant difference in the statistics (t=-12.504, P＜0.05). Conclusion Galactosylated chitosan has higher transfection efficiency than chitosan. GC-pGL3-hTERTp-TK could specially attack HCC cell line and almost has no influence on normal hepatic cells. Key words: Liver neoplasms, experimental; Chitosan; Target gene therapy; h-TERT promoter; Genes, trasgenis, suicide