Selective and enhanced transgene expression in hepatocellular carcinoma cells by asialofetuin-labelled liposomes and AFP promoter

In the present study, it was showed that combination with the plasmid DNA of genes under the control of α-fetoprotein (AFP) promoter and asialofetuin-labelled cationic liposomes (AF-liposomes) achieved specific and enhanced gene expression in AFP high-producing HCC cells. The plasmids, containing luciferase gene (pAFP-luc) or herpes simplex virus thymidine kinase gene (pAFP-tk) under the human AFP enhancer/silencer/promoter sequence, were complexed with AF-liposomes and transfected to established cancer cell lines. The transfection of pAFP-luc with AF-liposomes led to higher luciferase expression than that with control cationic liposomes in AFP high-producing hepatocellular carcinomas (HCC). Conversely, almost no expression was observed in AFP non-producing cell lines. Exposure of HepG2 cells to acyclovir following transfection of pAFP-tk with AF-liposomes decreased viability of the cells significantly. These results suggest AF-liposomes significantly enhance specific transgene expression driven by AFP promoter and have the potentiality of a non-viral vector in gene therapy for AFP-producing HCC.