Figure 3

Identification of an EGFR and STAT3 response element in the cyclin D1 promoter. (A) Schematic diagram of mutant cyclin D1 promoter constructs are shown. The expansion for EGFR and STAT3 binding site illustrates the wild-type sequence and frames the nucleotides replaced by mutations. (B-C) Dual luciferase-reporter assays were performed in LMP1-negative and LMP-positive CNE1 cells after co-transfection of a wild type or mutant cyclin D1 promoter-reporter construct, plasmids expressing wild-type EGFR or STAT3, and a Renilla luciferase transfection control plasmid. The fold induction by EGFR and STAT3 is displayed as the ratio of promoter activity obtained with wild-type compared to the DNA-binding mutant. (mean ± SD, n = 3, *p < 0.05, **p < 0.01). mt: mutation, wt: wild-type.