Figure 4.

The role of CHOP in the induction of persin-induced apoptosis. (A) MCF-7 cells were treated for 24 h with CHOP-specific siRNAs (siCHOP; 20 nM), non-targeting controls (siNT; 20 nM) or mock transfected and then treated for a further 24 h with an apoptotic concentration of persin (P; 10 μg ml⁻¹) or vehicle control (C). Protein samples were prepared and analysed for CHOP expression by immunoblotting. Representative blots from four independent experiments are shown. β-Actin was used as a loading control. (B) Attached and floating populations were then analysed for M30-FITC positivity by flow cytometry. Bars, mean of M30-positive fractions from four independent experiments±s.e. **P<0.005 for CHOP siRNA treatment vs NT siRNA treatment.