Figure 8. Regulation of MAPK signaling pathway by PCB1254 and miR-20b. (A) Total RNA was isolated from cells 24 hours after exposure of PCB1254, and the RNA level of Ras was gradually reduced. (B) Whole cell lysates were prepared 48 hours after exposure to PCB1254, and the results showed that as the concentration increased, the level of p-ERK1/2 gradually decreased. (C–F) the expression of Ras was decreased and the phosphorylation level was gradually decreased in the miR-20b overexpression group, whereas the silencing group was the opposite. (*: P<0.05).