Figure 6. PCN activates the EGFR-PI3K-AKT/MEK1/2-ERK1/2 MAP kinase signaling pathway that positively regulates NRF2 during oxidative stress.

Cytoplasmic or crude plasma membrane proteins of A549 cells previously exposed to PCN or sterile H₂O were probed with anti-phospho–specific antibodies. (A–D) PCN induces the phosphorylation of EGFR (A), AKT (B), MEK1/2 (C) and ERK1/2 (D). The experiments were repeated three times with similar results. Right panels represent densitometry analysis of western blots in (A–D). Densitometry data represent the mean ± SD from all three experiments. *p<0.05 when PCN-exposed cells were compared with the control cells exposed to same volume of sterile H₂O.