Hydrodynamic injection of naked plasmid DNA (pDNA) via the tail vein is a safe and effective method of gene transfer to the liver. However, successful gene transfer has yet to be shown for hepatocellular carcinoma (HCC); therefore, we investigated the feasibility and efficacy of hydrodynamic injection via the tail vein and hepatic artery in a diethylnitrosamine (DEN)-induced HCC model in rats.
HCC was induced in Sprague-Dawley rats by 100 ppm DEN in drinking water. pCMV-SPORT-β-galactosidase (β-gal, 400 µg) was injected (i) via the tail vein in a volume of 0.1 ml/g in 30 s or (ii) via the hepatic artery in a volume of 5 or 10 ml at 1 ml/s, either with or without temporary occlusion of the inferior vena cava (IVC) and portal vein (PV). The liver was harvested 24 h after administration, and β-gal expression was evaluated with X-gal staining and measurement of enzymatic activity in tissue homogenates.
Hydrodynamic injection via the tail vein achieved transgene expression only in non-cancerous tissue (tumor: 0.16 ± 0.04%, non-tumor: 5.07 ± 1.66%). Hydrodynamic injection via the hepatic artery was tolerated, but failed to produce efficient transgene expression in tumor and non-tumor cells. On the other hand, concomitant use of temporary IVC/PV occlusion with hydrodynamic injection via the hepatic artery dramatically increased transgene expression in cancer cells, but tumor-selective gene transfer was not achieved with this procedure (tumor: 7.38 ± 3.66%, non-tumor: 7.77 ± 1.06%).
High-volume hydrodynamic injection of a pDNA solution via the hepatic artery with IVC/PV occlusion achieved a high level of gene expression in a HCC rat model. This gene transfer technique may have potential in clinical gene therapy for HCC. Copyright © 2006 John Wiley & Sons, Ltd.