Figure 4

Tbx3 represses PTEN promoter activity. (A) EP-PTEN and CP-PTEN reporter plasmids were transfected into HeLa and HEK cell lines with (1μg) or without Tbx3 expressing plasmid. Using a luminometer, promoter activities of both plasmids were measured by means of luciferase activity. pGL3 control and pGL3 Basic plasmids were transfected into both of the cell lines as positive and negative controls, respectively. In both of the cell lines, expression of Tbx3 caused 3- to 4-fold reduction in the promoter activities of EP-PTEN and CP-PTEN reporter plasmids. Over expression of Tbx3 protein upon transfections was confirmed by western blots (WB) using an antibody against Tbx3 protein. (B) CP-PTEN reporter plasmid was transfected into both HeLa and HEK cell lines together with increasing amounts of a Tbx3 expressing plasmid. Promoter activity of CP-PTEN was then measured via luciferase assays using a luminometer. The sign “*”denotes for statistically significant decrease (p<0.05) in the PTEN promoter activity with respect to the basal activity of CP-PTEN as measured in the absence of Tbx3 expressing plasmid (100%). Expression of Tbx3 has been demonstrated by western blots (WB) using an anti-Tbx3 antibody.