FIG. 5.

Effect of TAM-67 on the activation of the TNFα promoter reporter in U937 cells. (A) The AP-1 binding site centered 102/103 bp 5′ of the transcription start site contributes to the activation observed in TAM-67-expressing U937 cells. U937 cells stably transfected with TAM-67 were transiently transfected with either the −120 or the −95 TNFα promoter reporter construct (3 μg). Sixteen hours later, the cells were harvested and RLU was determined and corrected for total protein in each lysate. The results presented are the means ± 1 SE of a transfection performed in duplicate and are representative of two experiments. (B) DN C/EBPβ inhibits activation of the −120 TNFα promoter reporter in U937 cells stably expressing TAM-67. U937 cells stably transfected with TAM-67 were cotransfected with the −120 TNFα promoter-reporter (3 μg) plus DN C/EBPβ (6 μg) or the CMV control vector (6 μg). Cells were harvested and analyzed as described above. The results presented represent the means ± 1 SE of an experiment performed in replicate and are representative of four experiments.