Publications (2)4.67 Total impact
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Article: Liver-specific gene therapy of hepatocellular carcinoma by targeting human telomerase reverse transcriptase with pegylated immuno-lipopolyplexes.
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ABSTRACT: The purpose of this study is to explore the possibility and feasibility of liver-specific gene therapy. A shRNA expression plasmid against human telomerase reverse transcriptase (hTERT) was constructed under the control of liver-specific promoter apolipoprotein A-I (ApoAI), designated as pApoAI-shTERT, and its liver-specific cytotoxicity and inhibition of telomerase activity were first evaluated in different cell lines, and its therapeutic effect was further studied in SMMC-7721 human liver tumor-bearing mice in vivo. The results showed that compared to pU6-shTERT, a shRNA expression plasmid against hTERT under the control of U6 promoter, pApoAI-shTERT only significantly diminished the cell viability in the telomerase positive hepatocarcinoma cells and showed no cytotoxicity in the telomerase negative cell lines as well as in the telomerase positive cell line of non-liver origin. Besides, pApoAI-shTERT only significantly reduced telomerase activity in the telomerase positive cell lines of liver origin. Intravenous administration of pegylated immuno-lipopolyplexes (PILP) formulated green fluorescent protein (GFP) expression plasmid under the control of ApoAI into liver tumor-bearing mice resulted in restricted GFP expression in liver and liver tumor. The treatment of pApoAI-shTERT formulated as PILP caused a 56% increase in the life span of SMMC-7721 tumor-bearing mice in vivo relative to the control, which was in agreement with the reduced tumor size and down-regulated hTERT mRNA level in the tumors. We conclude that the vector pApoAI-shTERT was able to cause liver-specific and hTERT target-specific cytotoxicity, and utilizing PILP to deliver pApoAI-shTERT is a promising strategy for liver-specific gene therapy.European journal of pharmaceutics and biopharmaceutics: official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V 01/2011; 78(3):320-5. · 3.15 Impact Factor -
Article: Construction, modification and evaluation of apolipoprotein A-I promoter-driven shRNA expression vectors against hTERT.
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ABSTRACT: Liver-specific gene knockdown cannot be achieved by short hairpin RNA (shRNA) generated by RNA polymerase III promoter. Here we constructed, modified and evaluated apolipoprotein A-I (ApoA-I) promoter-driven shRNA expression vectors against human telomerase reverse transcriptase (hTERT) in SMMC-7721 cells. The roles of the cis-acting hammerhead ribozyme and the specific pausing site MAZ, the liver-specific promoter ApoA-I, as well as SV40 and CMV enhancers were first individually evaluated, and then they were incorporated to construct a liver-specific shRNA expression plasmid against hTERT, and the inhibitory effects on hTERT were examined in SMMC-7721 cells. The results showed that the introduction of the cis-acting hammerhead ribozyme and the specific pausing site MAZ did not change gene knockdown efficiency significantly, but eliminated the off-target effect. Green fluorescent protein (GFP) expressing plasmid under the control of ApoA-I promoter can produce liver-specific GFP expression, but at a much lower level compared to the CMV promoter. The CMV or SV40 enhancer-modified ApoA-I promoter caused a four or two folds increase in mRNA expression of GFP relative to ApoA-I alone, respectively. The liver-specific shRNA expression plasmid against hTERT under the control of CMV enhancer-modified ApoA-I promoter with the sequences of the cis-acting hammerhead ribozyme and MAZ, induced significant inhibitory effect on hTERT at both mRNA and protein levels in SMMC-7721 cells. Therefore, liver-specific gene therapy is made possible by utilizing shRNA expression vector under the control of CMV enhancer-modified ApoA-I promoter.Plasmid 11/2010; 65(1):42-50. · 1.52 Impact Factor
