Figure 4.

Overexpression of ErbB2 decreased the mitochondria membrane potential following 3-BrPA treatment, inducing apoptosis. (A) The mitochondria membrane potential (MMP) was measured in 231V, 231ErbB2, BT474 scramble and BT474 siErbB2 cells following treatment with 3-BrPA at 200 µM for 4 h. (B) The cells groups were treated with 3-BrPA at 300 µM for 16 h, and the cytosolic and mitochondrial fractions were then isolated for western blot analysis. The high ErbB2-expressing cells exhibited more release of cytochrome C from mitochondria to cytoplasm under 3-BrPA treatments (left). The quantitation of the western blot analysis was quantified (right). (C) Whole cell lysates were isolated from the above 3-BrPA treated cells and subjected to western blot analysis for the detection of PARP cleavage. The high ErbB2-expressing cells exhibited increased levels of cleaved PARP following 3-BrPA treatment. Plotted data are mean values of three independent experiments; bars, SE. *P<0.05; **P<0.01.