Figure 4

Predicted NKX3.1 binding sequences of the TMPRSS2 promoter are portable repressor elements. (A) The transcriptional regulatory function of predicted NKX3.1 binding sites (NBS1-5) was assessed by luciferase reporter systems. Relative luciferase units are shown as fold changes relative to the control expression levels. Significant (P < 0.05) reduction of reporter gene expression are marked by asterics (B) Specific recruitment of endogenous NKX3.1 to predicted NBS1 and NBS4 binding sites of the TMPRSS2 promoter upstream regions was assessed by in vivo ChIP assay in the absence (NT) or presence of NKX3.1 siRNA (NKX).