Effect of SAT1 overexpression on growth arrest, apoptosis, and tumorigenesis. (A) Cells in the SAT1 Tet-on inducible stable cell line were treated with 0.5 μg/mL tetracycline for the indicated times followed by Western blot analysis. Actin was used as a loading control. (B) qRT-PCR analysis of mRNA levels of SAT1 in cells in the SAT1 Tet-on stable cell line at the indicated times after induction. (C) Representative phase-contrast images of SAT1 Tet-on stable cells uninduced (−) or induced with 0.5 μg/mL tetracycline (+) for 48 h. (Magnification: 10×.) The percentage of cells surviving at the indicated times is shown as mean ± SD. (D) SAT1 Tet-on stable cells were induced with 0.5 μg/mL tetracycline for the indicated times, and total protein lysates were subjected to Western blot analysis for the expression of PUMA, cleaved caspase3, cleaved PARP, and Actin. (E) Xenograft tumors from SAT1 Tet-on cells shown in A. (F) Tumor weight was determined (error bars indicate SD from four tumors in control mice and six tumors in Tet-on mice). ***P < 0.001.