HPLC analysis of lipoproteins in culture medium of hepatoma cells: an in vitro system for screening antihyperlipidemic drugs.

We isolated a HepG2-derived sub-clone (HepG2-Lipo), which possessed an increased lipoprotein synthesizing ability. HepG2-Lipo cells could secrete triglycerides (TG) and cholesterol at rates 9.4- and 6-fold higher, respectively, when compared to HepG2 cells. Real-time RT-PCR analysis revealed that the expression levels of sterol regulatory element-binding protein-1c and -2 were 2.9- and 1.5-fold higher than in HepG2 cells. Furthermore, two apolipoprotein (apo) genes (apoA-1 and apoB-100) in HepG2-Lipo cells were expressed at 2.8- and 1.9-fold higher levels when compared to those in parental cells. We examined the effects of three antihyperlipidemic agents on the lipoprotein profiles of HepG2-Lipo cells. Simvastatin at 5 microM selectively suppressed cholesterol secretion from HepG2-Lipo cells, and 500 microM fenofibrate inhibited both TG and cholesterol secretion from the cells.