New Insights into p53 Signaling and Cancer Cell Response to DNA Damage: Implications for Cancer Therapy

Figure 4

Dynamics of p53 and p21 protein levels in A172 (p53 wild-type) cells after exposure to ionizing radiation (IR; 5 Gy). (a) Representative Western blots showing p53 and p21 levels before (control) and at indicated times post-irradiation. CPTS staining (blue) was used to confirm equal amount of protein loading in each well. (b and c) Relative amounts of p53 and p21 protein levels at indicated times after irradiation. The data are expressed as normalized p21 and p53 values for irradiated samples relative to the values for the corresponding controls (set at 1). Bars, SE. Western blot analysis of p53 and p21 protein levels was performed using our published techniques [15].