ABSTRACT
OBJECTIVE@#To determine the role of extracellular signal regulated kinase (ERK) signaling pathway in SiO₂ induced epithelial-mesenchymal transition (EMT) in human bronchial epithelial cells (HBEC) in vitro.@*METHODS@#HBEC were treated with SiO₂ (0-300 μg/mL) for 72 h or pretreated with U0126 (0-30 μmol/L) for 1 h and then treated with 200 μg/mL SiO₂ for 72 h. Western blot was used to detect the protein expression of E-cadherin and α-smooth muscle actin (α-SMA). The activity of ERK was examined by mitogen-activated protein kinase (MAPK) activity assay kit in HBEC exposing to SiO₂ (200 μg/mL) for 0-8 h.@*RESULTS@#The expression of E-cadherin decreased gradually in SiO₂ -stimulated HBEC, and the effect was most significant at 300 μg/mL (P<0.01). The expression of α-SMA increased and the effect was most evident at 200 μg/mL (P<0.01). With SiO₂ treatment, the activity of ERK was upregulated significantly. The phosphorylation of ERK increased at 30 min and decreased after 1 h. U0126 significantly inhibited SiO₂ -induced expression changes in E-cadherin and α-SMA. At 30 μmol/L, the effect was most evident(P<0.01).@*CONCLUSION@#ERK signaling pathway mediated EMT induced by SiO₂ in HBEC.
Subject(s)
Humans , Actins , Metabolism , Bronchi , Cell Biology , Cadherins , Metabolism , Cell Transdifferentiation , Cells, Cultured , Epithelial Cells , Cell Biology , Physiology , Epithelial-Mesenchymal Transition , MAP Kinase Signaling System , Physiology , Mitogen-Activated Protein Kinases , Metabolism , Silicon Dioxide , PharmacologyABSTRACT
OBJECTIVE@#To investigate the expression of fibroblast growth factor-2 (FGF-2) and osteopontin (OPN) in non-small cell lung cancer (NSCLC) tissues and analyze the correlation between FGF-2 and OPN.@*METHODS@#Immunohistochemical SP method was used to detect the expression of FGF-2 and OPN in 76 patients with NSCLC and 15 normal lung tissues. The effect of FGF-2 on OPN expression at mRNA and protein level in A549 cell was examined by RT-PCR and Western blot.@*RESULTS@#The positive expression of FGF-2 (65.8%) and OPN (60.5%) in the NSCLC tissues was significantly higher than that in the normal lung tissues (13.3% and 0, respectively ) (P0.05).A positive correlation was found between the expression of FGF-2 and OPN in NSCLC (r=0.552,P<0.01). The expression of OPN protein and mRNA was up-regulated by FGF-2 in A549 cells.@*CONCLUSION@#The overexpression of FGF-2 and OPN is related to the metastasis and invasion of NSCLC.FGF-2 may promote the metastasis and invasion of NSCLC depending on the upregulation of OPN expression.