FIG 5.

Effect of etoposide treatment on p53 IRES activity in ZR75-1 and MDA-MB-175 cells. ZR75-1 (A) and MDA-MB-175 (B) cells were transfected with either pRF or pR5UTRF as described in Materials and Methods. At 48 h after transfection, the cells were treated with 10 μM etoposide for 2 h or were left untreated. The cells were then lysed with passive lysis buffer, and a dual-luciferase assay was performed as described in Materials and Methods. The results presented in panels A and B are averages ± the SEM from three individual experiments.