Fig. 7
From: PKNOX2 suppresses gastric cancer through the transcriptional activation of IGFBP5 and p53
IGFBP5 activates p53 signaling pathway in GC. a p53 mRNA and (b) protein was up-regulated by PKNOX2 overexpression in AGS and MKN45 cells; while an opposite trend was observed for GES1 cells. c PKNOX2 binds to the promoter of TP53. Binding motif of PKNOX2 was predicted by JASPAR database (red squares). ChIP-PCR validated the interaction between PKNOX2 and p53 promoter region. d PKNOX2 induced p53 luciferase activity in AGS and MKN45 cells(both P < 0.0001). e p53 signaling pathway PCR array showed that PKNOX2 overexpression up-regulated numerous p53 target genes in AGS and MKN45 cells. f Validation of differentially expressed genes by real-time PCR and RT-PCR. g and h Knockdown of IGFBP5 partly abolished the induction of p53 by PKNOX2 in AGS cells, as evidenced by real-time PCR and Western blot. IGFBP5 knockdown also down-regulated p53, p21 and p27 expression in GES1 cells. (*P < 0.05; **P < 0.01; ***P < 0.0001)
