Fig. 4.

Synergistic up-regulation of proapoptotic Noxa by the combination of ABT-737 plus chemotherapy. A, UM-22A cells were left untreated or were treated for 24 h with 0.1% DMSO, 10 μM ABT-737 alone, 10 μM cisplatin alone, 10 μM etoposide alone, ABT-737 plus cisplatin (10 μM each), or ABT-737 plus etoposide (10 μM each). After treatment, whole-cell lysates were prepared and subjected to immunoblotting for the indicated proteins. Similar results were seen in three independent experiments, and representative blots are shown. B, UM-22B cells exposed to ABT-737, cisplatin, or ABT-737 plus cisplatin for the indicated number of hours were subjected to immunoblotting for Noxa. The depicted results are representative of three independent experiments.