Figure 4.
Apoptosis upon Bcl-XL/Mcl-1 inhibition is initiated in the absence of altered BH3-only protein expression levels. (a) Primary human fibroblasts were treated with Bcl-XL/Mcl-1 or Ctrl siRNAs. Expression of pro-apoptotic Bim was quantified 3 days after transfection on RNA (left panel) or protein level (right panel). Data show means±S.D. and immunoblots are representative of three independent transfections. (b) Analysis of pro-apoptotic Bid in fibroblasts treated with indicated siRNAs for 3 days. Data show means±S.D. and immunoblots are representative of three independent transfections. (c–g) Analysis of Puma, Noxa, Bad, Bik and Hrk in fibroblasts as described in b. Data show means±S.D. and immunoblots are representative of three independent transfections