Figure 1.

Effect of tBHQ on luciferase production in HepG2 hepatoma cells transfected with TI-luciferase plasmids containing AREs, ARE mutants, or ARE-like sequences. The transfected plasmids carrying synthetic TI-promoter-luciferase reporter genes contained the indicated sequence in the multiple cloning site in the luciferase promoter region. The insert sequences are presented in Table 1. HepG2 cells were transfected as described with a mixture of the luciferase construct, pCH-110 (β-galactosidase reporter plasmid), and pUC19 (carrier plasmid). After 24 hr dishes of cells were treated with tBHQ (90 μM) or solvent (DMSO). Lysates were assayed for luciferase and β-galactosidase activities by standard assays. The values presented are the ratio of average luciferase activities (standardized to β-galactosidase activities) from treated versus untreated cell extracts. The averages were derived from three transfections.