PML Expression Represses IFN-γ-inducible IP-10 Promoter Activity.

<p>(A) The murine IP-10 promoter contains a putative GAS-like element (underlined). (B) NIH3T3 cells were co-transfected with the IP-10-luc reporter containing a GAS-like element and/or <i>Pml</i> siRNA, or the PML IV protein expression vector. Cells were either untreated or treated with murine IFN-γ (10 ng/ml) for 24 h, and then luciferase activity was determined. The pCMV-β-galactosidase vector was included to normalize transfection efficiency. Luciferase activity is normalized to the activity in the absence of IFN-γ and the activity from parental cells was arbitrarily set at 100% (RLA; relative luciferase activity). Increased or reduced PML protein expression in cell lysates transfected with either PML IV expression vector or <i>Pml</i> siRNA was verified by immunoblotting, respectively. (C) SNU-638 gastric cancer cells were co-transfected with the IP-10-luc reporter containing a GAS-like element and/or <i>Pml</i> siRNA, or the PML IV protein expression vector and analyzed as described in B. Values are the mean ± SD of three separate experiments. Bars, SD. *<i>P</i><0.05, **<i>P</i><0.001.