Figure 6

Maspin regulates the stability of Bcl-2 family proteins and the release of cytochrome c from mitochondria. A. Bax stability in TM40D cells. TC and T18 cells were induced with STS (1 μM) for 1 hour before they were treated by CHX (50 μM) for 0, 2, 3, and 4 hours. DMSO was used as a vehicle control (-CHX, 4 hrs). β-actin was used as a loading control. B. Release of cytochrome c protein from mitochondria to cytosol. TC, T16, and T18 tumor cells were treated with serum starvation for 48 hrs before they were harvested for preparation of cell extract and for cellular fractionation. Mitochondria were removed from cytosolic fraction by centrifugation. Both whole cell extracts and cytosolic fractions were subjected to Western blot analysis using antibodies against cytochrome c and beta-actin. β-actin was used as a loading control.