Fig. 1.
Induction of apoptosis by proteasome inhibition in CLL patient isolates. (A) DNA fragmentation analysis. Cells from a representative glucocorticoid-sensitive patient (see Table 1) were preincubated in the presence of 25 μmol/L zAPFcmk or 200 μmol/L zVADfmk for 1 hour and then treated with 10 μmol/L MG132, and DNA fragmentation was measured at 16 hours by PI staining and FACS analysis. (B) Surface phosphatidylserine exposure. Cells were incubated in absence or presence of 10 μmol/L methylprednisolone or 10 μmol/L MG132 with or without 200 μmol/L zVADfmk, and surface PS exposure was quantitated by staining with annexin-FITC and measured by FACS analysis. Results characteristic of three independent experiments with different patient isolates.