Fig. 5.

Higher levels of p53 phosphorylation are observed in mismatch repair-defective cells in response to the combination of honokiol and IR. A: p53 mRNA levels were analyzed by real-time PCR. Analyses of total RNA from HCT116 and HCT116-CH3 cells following combination of honokiol and IR treatment for 48 h showed upregulation of p53 mRNA (*P < 0.05). B: lysates obtained from HCT116 cells treated with the combination of honokiol and IR caused significant upregulation of phosphorylated p53 protein levels. In contrast, there were significantly lower levels of phosphorylated p53 protein levels in HCT116-CH3 cells.