Figure 2

Hyper-IL-6 dependent activation of the JAK/STAT signaling pathway. (A) Western blot analysis of phosphorylated STAT3 (P-STAT3) and unphosphorylated STAT3 in DU-145 cells after co-incubation with sterile filtered supernatants of mock- (-), GLV-1h68- (68) or GLV-1h90- (90) infected cells. Oncostatin M (OSM) served as positive control and gp130/Fc chimera was added in excess to the supernatants of GLV-1h90-infected cells (90/gp130) to show specific activation via cellular gp130. Hyper-IL-6 and oncostatin M dependent migration of STAT3 into the nuclei (B) and phosphorylation (C) of STAT3 in DU-145 cells were proven by immunofluorescent microscopy. Overlay images (large picture) resulting from cells stained for (phosphorylated) STAT3 (red), and Hoechst 33342 stained nuclei (blue) were depicted. Scale bars indicate 8.6 μm.