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Figure 3. p53 functional stabilization in pediatric ALL cells in response to RG7388. Western blot analysis for (A) established Nalm6 and CCREF-CEM cell lines and (B) representative of patient samples with functional p53 and dysfunctional p53. RG7388 showed stabilization of p53 and upregulation of p53 transcriptional target gene protein levels, MDM2 and p21^WAF1, 6 h after the commencement of treatment in wild-type TP53 Nalm6 and p53 functional ALL cells with the indicated doses (μM). However, it had no effect on downstream transcriptional targets of p53 in mutant TP53 CCRF-CEM and dysfunctional p53 patient samples with the delivered dose of RG7388 (μM); (C) western blot analysis indicated stabilization of p53 and induction of WIP1 expression following 6 h treatment with indicated doses of RG7388 (μM) in wild-type TP53 Nalm6 in a concentration manner. Conversely, there was no effect on the p53 stabilization and WIP1 expression in mutant TP53 CCRF-CEM with the delivered dose range of RG7388 (μM). RG, RG7388. ALL: Acute lymphoblastic leukemia; MDM2: mouse double minute 2 Homolog; WIP1: wild-type p53-induced phosphatase 1.