Silencing Proteases in Glioma Figure 4. Effect of bicistronic constructs on integrins and the expression of aVb3, a6b1 and a9b1 integrins on glioma xenografts and GBM clinical samples. (A) Western blot analysis depicting the reduced protein expressions of aV, a6, a9, b1 and b3 integrins after MMP-9/uPAR (MU-sh) and MMP-9/cathepsin B (MC-sh) plasmid shRNA treatments in 4910 cells. n = 3. Further, quantification of the Western blots (B) revealed significant reductions in protein expressions after MU-sh and MC-sh treatments. n = 3. Values shown are the mean (6SEM). *p,0.05 vs. control. (C) FACS analysis showing the presence of aVb3, a6b1 and a9b1 integrin heterodimers on 4910 glioma xenogaft cells. 4910 cells, in which iso match mouse IgG used as the primary antibody served as negative controls. NC-negative control (D) Immunohistochemistry of normal cerebrum and glioblastoma multiforme (GBM) for aVb3, a6b1 and a9b1 integrin heterodimer expressions. GBM tissue micro arrays were processed for immunohistochemistry. Prominent brown staining indicative of aVb3, a6b1 or a9b1 integrin expression was noticed in GBM samples. Scale bar = 100 mm. doi:10.1371/journal.pone.0011583.g004 PLoS ONE | www.plosone.org 6 July 2010 | Volume 5 | Issue 7 | e11583