Figure 5.

Involvement of putative TRE in TPFS-mediated PD-L1 inhibition. A549 cells stably transfected with reporter vectors under the control of PD-L1 promoter (pPD-L1-luc) or its mutants (pmTREPD-L1-luc and pdTREPD-L1-luc), in which the putative TRE was mutated or deleted as delineated at the left, were cultured in the absence or presence of the indicated concentrations of TPFS-202 for 48 h. Cells were subsequently harvested and cell lysates were subjected to the luciferase assay and protein determination. The luciferase values were normalized with respect to protein content. Normalized luciferase activity from vehicle-treated cells was set as 100% and the values in the compound-treated groups are expressed as the relative percentage. The results presented are from three independent triplicate transfections. ^*P<0.05 vs. untreated controls. TRE, TEAD response element; PD-L1, programmed death-ligand 1; pm, mutant; pd, deletion.