Figure 5.

Doxorubicin potentiates the apoptotic effects of TGase 2 silencing by extending p53 stability. (a) CAKI-1 cells were treated with siTGase 2 for 48 h, and then with doxorubicin for an additional 8 h before harvesting for immunoblotting of TGase 2, p53 and downstream markers of p53. (b) Viable cell was counted by using SRB staining after a single treatment of control siRNA, siTGase 2, or doxorubicin (1 μM), or a combined treatment of doxorubicin (1 μM) and siTGase 2. Y-axis presents viable cell per square mm. (c) To measure combination effect of doxorubicin with TGase 2 knockdown against RCC growth, XTT assay was employed under same conditions as (b). (d) To measure induction of apoptosis by dual treatments, CAKI-1 and ACHN cells were treated with a combination of GK921 and doxorubicin (1 μM) for 0, 8, 12, 18 and 20 h. Immunoblotting was performed against cleaved PARP and p-p53. (e) To measure combination effect of doxorubicin and GK921 against RCC growth, XTT assay was employed under same conditions as (d). Cumulative data from three independent experiments is shown here as mean±S.D. (n=3). *P<0.05, **P<0.01, ***P<0.001