Effect of cholesterol on regulation of the MFP-1, ThB and FPPS promoter reporter genes. The HepG2 cells were transiently cotransfected (5 hours) with -3400/+20 pGLuc, 132 pGLuc, 58 pGLuc, -2800 pTBGLuc or pFPPSGLuc luciferase reporter plasmid and pCH110 β-galactosidase reporter plasmid and mock treated (filled bars) or treated (open bars) with 25-hydroxycholesterol+cholesterol (mixture) for 48 hours. The data represent the average of three independent experiments with the error bars. Luciferase activities were normalised according to the protein concentration and β-galactosidase activities. Relative luciferase activities are given, taking as 1 the activity obtained for each plasmid in the absence of sterols.