MUC1-C activates the MYC promoter. (A) Schema of the pMYC-Luc vector with highlighting of the TBS at positions −270 to −263 with the germ line and mutant sequences. (B-E) RPMI8226 (B-C) and U266 (D-E) cells were transfected with (1) empty pGL3-Luc, (2) the indicated pMYC-Luc or mutant Mut-pMYC-Luc vectors, and (3) SV-40-Renilla-Luc as an internal control. Luciferase activity was measured at 24 hours after transfection. The results (mean ± SD of 3 determinations) are expressed as the relative luciferase activity compared with that obtained with cells expressing pGL3-Luc. TSS, transcription start site.