Mcl-1 AS ODNs inhibit Mcl-1 protein levels and induce apoptosis of MM cells.

Mcl-1 AS ODN or inverted control ODN (Inv) was introduced into 8226 cells by means of streptolysin-O (SLO). (A) At 4 and 8 hours after transfection, cell lysates were prepared, and Western blot analysis was performed with the use of antibodies directed against Mcl-1, Bcl-2, or Bcl-XL. Lane 7 contains extracts from 8226 cells grown under standard conditions (complete medium plus IL-6). (B) At 3 or 6 hours after the introduction of AS or Inv ODN, cells were harvested and cell lysates analyzed for effector caspase activity. Extracts in the lane marked ActD were from cells cultured for 6 hours in the presence of actinomycin D (1 μg/mL). (C) The 8226 cells were treated with SLO alone (Ci), SLO plus Inv ODN (Cii), SLO plus AS ODN (Ciii), or actinomycin D (1 μg/mL) (Civ), and cultured for an additional 6 hours. Cytospin preparations were fixed and then stained with Hoechst 33342. Magnification, × 400.