Hexamethylene bisacetamide (HMBA) stimulates the release of mitochondrial cytochrome c and loss of Bcl-2.

(A) Cytosolic extracts from CCRF and A7 CEM cells either untreated or treated with 10 mmol/L HMBA for 72 hours were separated by SDS/PAGE, and Western blots were performed using anti-cytochrome c monoclonal antibody (mAb) that migrates at approximately 15 kd. The same blots were reprobed with anti-α-Tubulin mAb denoted by a band of approximately 50 kd. In some wells, cells were pre-incubated for 4 hours with 40 μmol/L ZFA-fmk or ZVAD-fmk. (B) CCRF and A7 CEM cells were either untreated or treated with 10 mmol/L HMBA for 72 hours. In some wells, cells were pre-incubated for 4 hours with 40 mmol/L ZFA-fmk or ZVAD-fmk. Protein lystates were separated by SDS/PAGE, and Western blots were performed using anti-Bcl-2 mAb that detects a specific band of approximately 28 kd. The same blots were reprobed with anti-α-Tubulin mAb seen migrating as a 50-kD protein.