Figure 6
The role of EpCAM, integrin β4 and uPA in migration and invasion of DU145-LN4 cells. Cell migration of DU145-LN4 cells in a transwell migration assay (A-C) and a Matrigel invasion assay (D-F). siRNA knockdown of (A) EpCAM, (B) integrin β4, or (C) uPA significantly inhibited cell migration relative to control siRNA and untreated cells. siRNA knockdown of (D) EpCAM or (E) ITGB4 did not significantly affect cell invasion in a Matrigel invasion assay. (F) uPA siRNA significantly inhibited cell invasion relative to control siRNA and untreated cells. Western blot analysis of whole cell lysates from cells treated with siRNA in parallel with migration/invasion assays: (G) EpCAM, (H) integrin β4, and uPA western blots. Blots were probed with GAPDH as loading controls. (I) Western blot analysis of whole cell lysates from cells treated with control siRNA or si-uPA and serum starved (−) or serum stimulated (+). p-AKT and p-S6K were induced after serum addition in control cells but not in cells lacking uPA. Total AKT, S6K, and GAPDH served as controls. DU145-LN4 cell migration (J), and cell invasion (K) were significantly inhibited by treatment with 10 μM amiloride or 10 μM UK122. Students t-test, *p ≤ 0.05, **p ≤ 0.01, n.s.-not significant. Top asterisked p value represents analysis between untreated cells and specific siRNA, lower value indicates analysis between control siRNA treated cells and specific siRNA.