Fig. 4
From: Integrin-uPAR signaling leads to FRA-1 phosphorylation and enhanced breast cancer invasion
Vitronectin (VN)-stimulated Fos-related antigen 1 (FRA-1) phosphorylation requires urokinase/plasminogen activator urokinase receptor (uPAR) expression. a Expression of selected integrin subunits and uPAR in a panel of human breast cancer cell lines. b Quantitative PCR analysis of plaur expression in selected human breast cancer and BRC cell lines. Data presented are the mean expression from three independent RNA extractions and plaur expression is normalized to actb. Error bars represent the standard error of the mean. BaA basal A subtype; BaB basal B subtype; Lum, luminal subtype. c Immunoblot analyses of BT549, BRC-31 and HCC1143 cells transfected with siRNAs against plaur (U) or scrambled control (S), which were subsequently plated on plastic (PL), a low (40 ng/cm2) or high (400 ng/cm2) concentration of VN for 30 minutes. Representative blots from one of three independent experiments are shown. FAK, focal adhesion kinase; ERK, extracellular signal-related kinase. d The level of phosphorylation of FRA-1 was quantified and expressed as a ratio to the loading control α-Tubulin. The data from three independent lysates are plotted and the error bars represent the standard deviation between samples. *P ≤ 0.05