Figure 4.

Leptin activates epithelial-to-mesenchymal transition-related ERK signaling pathway in A549 cells. (A) Protein levels of p-ERK and total-ERK were measured by western blot analysis after A549 cells were treated with TGF-β1 or leptin for 48 h (n=6). (B) The relative content of p-ERK was calculated against β-actin. (C) Protein levels of p-AKT and total-AKT were measured by western blot analysis after A549 cells were treated with TGF-β1 or leptin for 48 h. (D) The relative content of p-AKT was calculated against β-actin. Values are expressed as mean ± standard error of the mean. ^#P<0.05, ^##P<0.01 vs. the control group. AKT, protein kinase B; TGF, tumor growth factor; ERK, extracellular signal regulated kinase.