PRIMA-1^Met did not increase expression of the p53 target genes p21 and DR5 but did increase the expression of Noxa. (A) PRIMA-1^Met did not induce the expression of the p53 target gene p21. XG6 (TP53^wt), OPM2 (TP53^R175H), and JJN3 (TP53^neg) cells were treated overnight with 35 μM PRIMA-1^Met, with or without 5 mM NAC. Protein expression was assessed using western blotting. (B) PRIMA-1^Met did not increase the expression of the p53 target gene DR5. Cells, treated as described in the legend of Figure 2A, were strained with control-PE immunoglobulin or anti-DR5-PE mAbs, and fluorescence was analyzed on a FACsCalibur. The ratio of fluorescence was determined by dividing the specific fluorescence mean by the control fluorescence mean. Control staining of untreated and treated cells was identical and is not represented in the figure. The data represent 1 experiment out of 3.