HeLa-S3 cells (JCRB Cell Bank) were cultured in MEM (WAKO) supplemented with 10% FBS (NICHIREI BIOSCIENCE INC., Lot No. 7G0031), 100 Units/mL penicillin and 100 μg/mL streptomycin (both Life Technologies). HepG2 Cells (RIKEN BRC) were cultured in DMEM (Life Technologies) supplemented with 10% FBS (NICHIREI BIOSCIENCE INC., Lot No. 7G0031), and MEM (WAKO) supplemented with 10% FBS (NICHIREI BIOSCIENCE INC., Lot No. 7G0031), 100 Units penicillin and 100 μg/mL streptomycin (Life Technologies). Cell lines were seeded into 96 well plates at a density of 7.5 × 103 cells/well one day before transfection. Firefly luciferase reporter plasmids (190 ng) and 10 ng of pGL4.73 renilla luciferase plasmid (Promega) were co-transfected into HepG2 or HeLa-S3 cells using Lipofectamine (Life Technologies) according to the manufacturer's instruction. Each transfection was independently performed three times. After 24 hours, the luciferase activities were measured by GloMax 96 Microplate luminometer (Promega) using the Dual-glo luciferase assay system (Promega) according to the manufacturer's instruction.
