Luciferase reporter assays for L1CAM promoter 1 and promoter 2. (A and B) Schematic illustration of luciferase promoter constructs of variable length. The E-boxes (E1-E9) and LEF-1 binding sites (LE1-LE4) have been labelled in a consecutive fashion and are indicated. Note that the constructs contain variable number of E-boxes and LEF-1 binding sites and are referred to as L1-P1 to L1-P3 (from promoter 1) and A-F (from promoter 2). (C and D) Luciferase activity assay in Ishikawa cells using the indicated promoter constructs. Values have been normalized to the internal control (renilla) to account differences in transfection efficiency. The pGl3 vector was used as negative control and pGl3-SV40 as positive control. Luciferase activity was determined after 48 h. A representative experiment from each n = 4 is shown. (E) Luciferase activity assay of promoter 1 reporter constructs L1-P1 to -P3 in Ishikawa cells using the indicated constructs in combination with overexpression of Snail-HA, Slug-HA, stabilised β-catenin or pcDNA3 negative control. (F) Luciferase activity assay of promoter 2 reporter constructs A-D in Ishikawa cells using the indicated constructs in combination with overexpression of Snail-HA, Slug-HA, stabilised β-catenin or pcDNA3 negative control. Data ± SD of a representative experiment from n = 3 is shown. (*** p ≤ 0.001, **p ≤ 0.01, *p ≤ 0.05, n.s. not signicicant).