FIGURE 7.

Smad7 suppresses the in vivo tumor formation. A, to check the effect of Smad7 on tumor formation, we performed xenograft experiment with 10 nude mice per group. After inoculating control and Smad7 cells onto mammary fat pads, TRAIL was loaded by intraperitoneal injection for 10 days. Tumor size was measured every 3 or 4 days, and volume was calculated as described under “Experimental Procedures.” B, after sacrificing the mice, tumor tissues were fixed and checked with H&E staining. C, to measure the induction of apoptosis in TRAIL-treated tumors, TUNEL assay was performed. Nuclei were stained with DAPI. Scale bar indicates 50 μm. D, to check expression of apoptotic markers, tumor tissues were lysed and detected with Western blotting. Caspase 8, PARP, and activated caspase 3 were detected with specific antibodies, and β-actin was used as normalization control.