Figure 7

SM22 re-expression reduces PC3 Matrigel invasion and podosome formation. Re-expression of SM22 in PC3 cells reduces significantly the number of cells invading and traversing the filter in Matrigel coated Boyden chamber assays in response to a serum gradient (A); mean ± SEM 3 independent experiments, * p < 0.03 PC3 compared to PC3-SM22 in 0-10% gradient. PC3 cells stained for F-actin (B, E, H red in merge), cortactin (C, F, I green in merge). Cells in B-G are control PC3, cell in H-J is expressing SM22. Normal PC3 exhibit prominent ruffling membranes and podosomes (arrowed) as indicated by the co-staining of F-actin and cortactin, whereas SM22 expressing PC3 cells have reduced ruffling membranes and are devoid of podosomes.