Figure 4: Inhibiting TGase 2 with GK921 induces apoptosis in RCC through transcriptional activation of p53. A. Apoptotic effect of GK921 in ACHN and CAKI-1 cells was analyzed by immunoblotting with antibodies to p53, poly(ADP-ribose) polymerase (PARP), and β-actin. The blots shown are representative of more than three independent experiments. B. Expression of p53 increased in ACHN and CAKI-1 cells exposed to GK921 (1μM) for 4 h. Cells were analyzed by immunocytochemistry using anti-p53 primary antibody and fluorophore-conjugated anti-rabbit immunoglobulin secondary antibody, and counterstained with 4,6-diamindino-2-phenylindole to visualize nuclei. Scale bar, 50 mm. C. CAKI-1 cells were transfected with Bax-Luc reporter construct and then exposed to GK921. Lysates were subjected to luciferase assay. D. Caki-1 cells were transfected with control siRNA or TGase 2 siRNA along with Bax-Luc reporter construct. E. HEK293 cells were transfected with Bax-Luc reporter construct and then exposed to GK921 (1 μM). Graph; meanĀ±SE. *p<0.05.