FIGURE 4.

Phosphorylation and stabilization of p53 by the combination of luteolin and EGCG. H460 (A) and A549 (B) cells were treated with luteolin (L), EGCG (E), or their combination (C), and total cell lysates were immunoblotted with anti-p53 (Santa Cruz Biotechnology) and anti-phospho p53 (Ser¹⁵, Cell Signaling Technologies). Representative data from three independent experiments are shown. Numbers below each lane represent fold change. C, H460 cells were pretreated with 10 μm Ku55933 for 1 h, followed by treatment with 20 μm luteolin, 30 μm EGCG, their combination, or 2 μg/ml camptothecin (Cp) for 48 h. Cells were treated with capmtothecin for 24 h. Total cell lysates were immunoblotted with antiphospho p53 Ser¹⁵. Representative data from three independent experiments are shown. D, H460 cells were treated with luteolin, EGCG, their combination, or camptothecin for 24 h. Total cell lysates were immunoblotted with phospho-H2AX (γ-H2AX) and p53. Experiments were repeated three times. NT, no treatment.