Time-course of flavopiridol- and UCN-01–induced decreases in XIAP and Mcl-1 protein levels.

B-CLL cells were cultured with (shaded symbols) or without (open symbols) 0.1 μmol/L flavopiridol (panels A and B) or 1 μmol/L UCN-01 (panels C and D). At various times, cells were recovered from cultures, and either lysates were prepared for immunoblot analysis (circles) with the use of antibodies specific for XIAP (panels A and C) or Mcl-1 (panels B and D) and the data were expressed as a percentage of untreated cells, or apoptosis was determined by TUNEL assay (squares). Data are representative of results obtained from 3 consecutive B-CLL specimens.