Luciferase reporter assay: Cells (2 × 105) were seeded in six-well plates and transfected with 1 µg DNA. At 48 h post-transfection, cells were lysed in 400 µL passive lysis buffer (Promega). Luciferase assays were performed according to the manufacturer's instructions (Luciferase Assay System, Promega). Results were normalised for protein concentration with all experiments being performed a minimum of three times before calculating means and standard error of the means.