Enhanced plasma cholesterol lowering effect of retrovirus-mediated LDL receptor gene transfer to WHHL rabbit liver after improved surgical technique and stimulation of hepatocyte proliferation by combined partial liver resection and thymidine kinase ganciclovir treatment

In the study we report an improved method for in vivo gene transfer to live r. Repealed injections of Moloney murine leukemia virus-derived retroviruse s containing LDL receptor cDNA were given to the portal vein in combination with 10% partial liver resection and stimulation of hepatocyte proliferati on by plasmid/liposome-mediated thymidine kinase gene transfer and ganciclo vir treatment The method was used for the treatment of LDL receptor deficie ncy in Watanabe heritable hyperlipidemic rabbits. We demonstrate an increas e in hepatocyte proliferation index by thymidine kinase and ganciclovir tre atment from 0.9 to 1.35% and a maximum of 35% decrease in total plasma chol esterol level 2-3 months after the gene transfer. A 20% decline was still p resent after a 52-week follow-up period. A 50% decrease was also observed i n plasma triglycerides. Liver function tests indicated a transient increase in plasma alkaline phosphatase level up to 12 weeks after the gene transfe r. In situ PCR and RT-PCR analyses indicated that the transgene was present in periportal areas and was transcribed to mRNA 1 week after the gene tran sfer. Because of the relatively simple and controllable technique we sugges t that repeated retrovirus injections via a portal vein catheter together w ith the limited partial liver resection and plasmid/liposome-mediated thymi dine kinase gene transfer-ganciclovir treatment may be used to improve the results of retrovirus-mediated liver gene therapy.