COX-2-directed migration of human chondrosarcoma cells involves up-regulation of α2β1 integrin. (A) JJ012 cells were incubated with PGE2 for 24 hr, and the cells surface α5, α2, β3, α5β1, αvβ3 and α2β1 integrin was determined using flow cytometry. (B) Cells were incubated with PGE2 for 24 hr, and the mRNA levels of α2 and β1 integrin was determined using qPCR. (C) JJ012 cells were transfected with IPTG/COX-2 expression plasmid or control vector for 24 hr followed by stimulation with IPTG (5 mM) for 24 hr, the mRNA expression of α2 and β1 integrin was determined by qPCR. JJ012 cells were incubated with PGE2 for indicated time intervals, and mRNA and cell surface α2β1 integrin were examined by qPCR (D) and flow cytometry (E). (F) Cells were pretreated with α2β1 monoclonal antibody (3 μg/ml) for 30 min followed by stimulation with PGE2. The in vitro migration activity measured after 24 hr. (E) JJ012 cells were treated with 17-phenyl trinor PGE2 (3 μM), 11-deoxy-PGE1 (10 μM), PGE2, and PGE2 plus SC19220 (10 μM), and cells surface α2β1 integrin was determined using flow cytometry. Results are expressed as the mean ± S.E. *, p < 0.05 compared with control; #, p < 0.05 compared with PGE2-treated group.