Figure 3. NDGA induces apoptosis of trastuzumab-refractory cells.
(A) SK-parental, SK-HRp2, and SK-HRc3 cells, and (B) BT-parental and BT-HRp3 cells were treated with 0, 25, 50, or 100 μM NDGA for 6 h. Immunoblotting (50 μg) was performed for PARP and caspase 3 cleavage. Actin served as a loading control. Blots were repeated at least twice to ensure reproducible results, and representative blots are shown. NDGA activated cleavage of PARP from the full-length 116-kDa form to the 89-kDa form, and of caspase 3 into the 19-kDa and 17-kDa forms, indicating induction of apoptosis by NDGA. The cleaved 89-kDa PARP and 19-kDa caspase 3 bands were quantitated using NIH ImageJ software.

