Effect of NF-κB inhibition on cytochrome

c release from the mitochondria to the cytoplasm.NF-κB inhibition induces cytochrome c release from the mitochondria to the cytoplasm. Cytochrome c protein levels (nanograms per microgram of total protein, mean ± SD) were measured in the cytoplasmic and mitochondrial fractions of MM.1S cells treated with (white bars) or without (black bars) SN50 (20 μM) for 4 hours. Treatment with SN50 induced a rapid decrease of cytochromec in the mitochondrial fraction of MM.1S cells, associated with an increase of cytochrome c in the cytosolic fraction.