Thrombin differently induces ERK1/2 activation in Met-5A and NCI-H28 cells.

A, relative intensity of pERK1/2 immunoreactive bands quantified by densitometric scanning. Serum and growth factor starved Met-5A and NCI-H28 cells were incubated in the presence and absence of various thrombin concentrations ranging from 0.01 to 100 nM for 5 min. ERK1/2 activation was then determined using a specific anti-phospho-ERK1/2 antibody. Nitrocellulose membranes were then stripped and reprobed for total ERK1/2. Data (mean ± SEM) are expressed as fold-increase over Ctrl and are the averages of three independent experiments performed in duplicate. The differences in phosphorylated ERK1/2 level between Ctrl (vehicle treated Met-5A or NCI-H28 cells) and thrombin-treated cells were significant (*P≤0.05, **P≤0.01) by one-way ANOVA followed by Bonferroni’s multiple comparison test. B, a representative immunoblot.