GRIM-19 Disrupts E6/E6AP Complex to Rescue p53 and Induce Apoptosis in Cervical Cancers
Figure 2
GRIM-19 induced p53 protein accumulation in HR-HPV infected cervical tumor cells.
(A & B) The protein levels of GRIM-19 and p53 in primary cervical cancers. Western blotting with the indicated antibodies was performed using lysates from the indicated cell lines. (C) Effect of GRIM-19 on p53 mRNA expression. The mRNA of GRIM-19 (left panel) significantly high in HeLa/pG19 cells (* p<0.01), the right panel shows p53 mRNA expression. Differences are not statistically significant. (D) GRIM-19 did not affect the p53-promoter activity. A p53-Luc reporter was used. The data presented are the mean of three independent experiments with triplicate samples in each test. (E) GRIM-19 increases the half-life of p53. Cells were treated with CHX (100 µg/ml) for the indicated time periods and lysates were subjected for Western blotting with the indicated antibodies. Representative results from one out of three independent experiments are shown (left panel). The remaining value for p53 was calculated as the ratio of the densitometric values of p53 over GAPDH in each sample (right panel). The average remaining values from three independent experiments were plotted. (F) GRIM-19 inhibited p53 degradation in vivo. Before harvesting the cells were treated with MG132 for 4 h, and immunoprecipitation with p53 antibody was performed. Western blotting of the IP products was using ubiquitin antibody. GAPDH antibodies were used to determine the comparable loading.