Luciferase Reporter Assay

For measurement of the transcriptional activity of FoxM1, luciferase report assay was conducted according to the previous study (Smale, 2010). Following FoxM1-luc reporter vector (containing FoxM1 proximal promoter) transfection, cells were treated with agent and luciferase report assay was performed 48 h later. Then the relative luciferase activity was analyzed. For the dual-luciferase assay, the human ABCB1 gene promoter was sub-cloned into pGL3 vector (wild-type:5′-TTTGTTTGTTTT-3′ or mutant: 5′-TCCATCCAGGGT-3′) (Promega, MA, USA) in HEK293T cells. Cells were co-transfected with ABCB1 promoter vector, pcDNA-FoxM1 and internal control plasmid, and luciferase assays were performed 48 h after transfection using the Firefly/Renilla Dual Luciferase Reporter Assay System according to the manufacturer’s instructions (Promega, MA, USA).