Figure 2
(a) Cropped blots related to the effect of compounds 17b and 24 on α5β1 integrin-mediated phosphorylation of ERK1/2 in K562 cells. Cells were serum-starved in RPMI-1640 containing 1% FBS for 16 h; then cells were preincubated with different concentrations of the antagonist 17b (10−7–10−9 M) or its vehicle for 1 h in suspension and then were allowed to adhere for 1 h on fibronectin (FN). Cells treated with the agonist 24 (10−7–10−9 M) were not incubated with fibronectin. Thereafter cells were lysed and lysates were analysed in Western blot using an antibody directed against phosphorylated ERK1/2 (pERK1/2) or total ERK1/2 (totERK1/2). Western blot showed that cells plated on FN had a much stronger signal for phosphorylated ERK1/2 than vehicle-treated cells. Compound 17b prevented FN-induced phosphorylation of ERK1/2 in a concentration-dependent manner, while agonist 24 significantly increased ERK1/2 phosphorylation. Full-length blots are presented in Supplementary Figure S40. (b) Densitometric analysis of the bands (Mean ± SEM; n = 4); the amount of pERK1/2 is normalized to that of totERK1/2. *p < 0.05, **p < 0.001 vs. FN; #p < 0.05. ##p < 0.01 vs. vehicle (Newman-Keuls test after ANOVA).
