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Gene delivery using a receptor-mediated gene transfer system targeted to hepatocellular carcinoma cells
Abstract:
For gene therapy to be effective in cancers, it is necessary to deliver therapeutic genes into cells with high specificity and efficiency. In this study, we examined the in vitro and in vivo gene delivery efficiency of a new, growth receptor-mediated gene transfer system in hepatocellular carcinoma (HCC). The effects of transfection of wild-type p53 using this system were also studied. The system consisted of a ligand oligopeptide for epidermal growth factor receptor (EGFR) recognition, a polypeptide for DNA binding, and an endosome-releasing oligopeptide for endosomolysis. Two human HCC cell lines and a normal liver cell line were used, and pCMV-beta-galactosidase (beta-gal) was used as a reporter gene. Both HCC cell lines had strong expression of EGFR and the in vitro transfer efficiency peaked at day 5 at about 50%. This finding was in contrast to the normal liver cell line, which had weak EGFR expression and less than 1% transfer efficiency throughout. For in vivo gene transfer in tumors produced by inoculating HCC cells in nude mice and with the vector-beta-gal gene complex injected peritumorally, beta-gal expression was detected within the tumors at 12 hr, peaked at day 5 involving about 50% of the tumor cells and persisted at 2 weeks. Using this vector system, transfection of wild-type p53 into Huh-7 cells that had mutated p53 resulted in significant growth inhibition of cancer cells accompanied by a decreased G2/M phase and increased p53 protein. In conclusion, this receptor-mediated gene transfer system appears to work specifically in HCC cells with high efficiency, and may be promising in delivering apoptotic and other genes into HCC cells.
Insights
This study introduces a novel gene transfer system targeting hepatocellular carcinoma (HCC) via epidermal growth factor receptor (EGFR). The system demonstrated high efficiency in delivering genes to HCC cells both in vitro and in vivo, showing promise for cancer gene therapy.
Area of Science:
- Oncology
- Molecular Biology
- Biotechnology
Background:
- Effective cancer gene therapy requires specific and efficient delivery of therapeutic genes.
- Hepatocellular carcinoma (HCC) presents a significant challenge for targeted treatment strategies.
- Growth factor receptor-mediated gene transfer offers a potential avenue for enhanced delivery.
Purpose of the Study:
- To evaluate the in vitro and in vivo gene delivery efficiency of a novel growth receptor-mediated system in HCC.
- To investigate the effects of wild-type p53 gene transfection into HCC cells using this system.
- To assess the specificity of the gene transfer system for HCC cells over normal liver cells.
Main Methods:
- Development of a gene transfer system comprising an EGFR-ligand oligopeptide, DNA-binding polypeptide, and endosome-releasing oligopeptide.
- In vitro gene transfer assays using two human HCC cell lines and one normal liver cell line with a beta-galactosidase reporter gene.
- In vivo gene transfer studies in nude mice bearing HCC tumors, with peritumoral injection of the vector-gene complex.
- Assessment of wild-type p53 transfection effects on Huh-7 HCC cells with mutated p53.
Main Results:
- The system achieved approximately 50% gene transfer efficiency in HCC cell lines in vitro, peaking at day 5.
- Normal liver cells with low epidermal growth factor receptor (EGFR) expression showed less than 1% transfer efficiency.
- In vivo studies detected beta-galactosidase expression in ~50% of tumor cells by day 5, persisting for 2 weeks.
- Wild-type p53 transfection significantly inhibited Huh-7 HCC cell growth, reduced the G2/M phase, and increased p53 protein levels.
Conclusions:
- The developed receptor-mediated gene transfer system exhibits high specificity and efficiency for HCC cells.
- This system holds promise for delivering therapeutic genes, such as apoptotic or tumor suppressor genes, into HCC.
- The findings suggest a viable strategy for advancing gene therapy approaches in hepatocellular carcinoma treatment.