FIGURE 5.
HBXIP recruits p300 to transcription factor p53 to activate MDM2 promoter. A, P2 promoter activities of MDM2 were tested by luciferase reporter gene assays in MCF-7 cells. B, P2 promoter activities of MDM2 were examined by luciferase reporter gene assays in MCF-7 cells. C, P2 promoter activities of MDM2 were measured by luciferase reporter gene assays in MCF-7 cells. The efficiency of HBXIP siRNA was determined using Western blot analysis (WB). D, the interaction of p300 with p53 was detected by co-IP assays in MCF-7 cells. E, MCF-7 cells were transfected with HBXIP siRNA. ChIP assays were measured 24 h after transfection. F, the interference efficiency of p300 siRNA was tested in MCF-7 cells. G and H, the acetylation levels of histone H3 were examined by co-IP assays in MCF-7 cells with different treatments. Each experiment was repeated at least three times. Student's t test; *, p < 0.05; **, p < 0.01.