Transcription Factor Sp1 Is Involved in Expressional Regulation of Coxsackie and Adenovirus Receptor in Cancer Cells
Figure 2
Effect of the mutation in Sp1 binding motif or Sp1 on CAR promoter activity. (a, b) For the examination of the effect of Sp1 on the promoter activity, either Sp1 or its dominant negative form (Sp1 DN) was cotransfected into MCF-7 (a) and PC-3 cells (b) with reporter construct of core promoter and β-galactosidase gene in the presence or absence of mithramycin. *, *** relative to pCMV vector control, ** relative to Sp1 control. (c, d) For the examination of the effect of Sp1 binding site on the core promoter activity in response to ectopic expression of Sp1, either wild type or mutant type of core promoter was cotransfected with Sp1 and β-galactosidase into MCF-7 (c) and PC-3 (d), and the following procedures were identical to above case. From total cell extracts, luciferase activities were examined and normalized by β-galactosidase activity. The relative luciferase activities were determined by statistical analysis of three independent experiments. #, # # # relative to pGL3 vector control, # # relative to wild-type core promoter (−585/−400) DMSO. Bars represent the mean ± SD.
