Figure 5. Overexpression of ERK5 reverses TS-triggered EMT morphological change and migratory and invasive capacities of normal human bronchial epithelial (NHBE) cells.

NHBE cells were stably transfected with lentiviral control vector or ERK5 expression vector at a multiplicity of infection of 25 for 72 hours, and then exposed to cigarette smoke extract (CSE) for 7 days. A. ERK5 expression vector restored CSE-suppressed ERK5 activity and attenuated CSE-induced activation of AP-1 subunits (c-Fos, c-Jun and Fos B) in NHBE cells, as measured by Western blotting. B. ERK5 overexpression reduced CSE-triggered migratory capacity of NHBE cells shown by migration assay. C. ERK5 overexpression decreased invasive capacity of NHBE cells as determined by invasion assay. LV-control = lentiviral control vector; LV-ERK5 = lentiviral expression vector for ERK5. *P < 0.05, **P < 0.01, compared with control group; ^#P < 0.05, ^##P < 0.01, compared with lentiviral control vector group.