Figure 5.

Only Noxa synergizes with ABT-737 in Bcl-B, Bfl-1 and Mcl-1 overexpressing cells. J16 clones with Dox-inducible expression of the indicated BH3-only proteins and overexpression of Bcl-B, Bfl-1 or Mcl-1, were tested for interaction of the BH3-only protein with ABT-737. (a) Cell death assay: Cells were treated with ABT-737 at 80, 400, 2000, or 10000 nℳ, in the absence or presence of Dox (Bim and Noxa, 1 μg/ml; Puma, 0.25 μg/ml; tBid-C, 0.03 μg/ml). Cell death was assessed by PI uptake after 48 h. Data shown are mean values+S.D. derived from three independent experiments. CI indicate synergy. (b) Clonogenic assay: Cells were sorted at one cell per well into round-bottom 96-well plates, with medium alone (control), or added ABT-737 (1 μM), Dox (2 μg/ml), or both. Cells were allowed to proliferate for 3 weeks, and wells with evident colonies were scored positive. Colony formation in medium alone was set at 100%. Data shown are mean values+S.D. derived from three independent experiments