Figure 4.

Depletion of OPN suppresses cell proliferation, colony formation, and tumorigenesis. (A) Two independent shRNAs that target OPN (shOPN¹ and shOPN²) or a control shRNA (shSc) were stably expressed in Tca8113 cells. The expression of OPN was examined by western blotting and β-actin was used as a control. (B) The proliferation of Tca8113 cells expressing shSc, shOPN¹, or shOPN² was examined by MTT assay. Data indicate mean ± SD of triplicate samples. *P<0.05, **P<0.01, ***P<0.001, compared with the respective controls. (C) The number of colonies formed in soft agar by Tca8113 cells expressing shSc, shOPN¹, or shOPN². Representative images were presented. Data indicate mean ± SD of triplicate samples. **P<0.01, compared with the respective controls. (D) Tca8113 cells expressing shSc or shOPN¹ were inoculated subcutaneously into nude mice, and followed for tumor development (top panel) and survival (bottom panel). (E) Tumor tissues from these nude mice were subjected to immunoblotting for OPN expression and β-actin was used as a control. (F) Tumor tissues were subjected to immunohistochemical staining. Representative images were presented.