α-TEA induces apoptosis in human breast cancer cells. A & B, MDA-MB-231 cells were treated with 40 μM α-TEA for 9, 15, and 24 hrs. Apoptosis was determined by FACS/Annexin V assay (A) and depicted in graphic form (B). C, Western blot analyses were used to detect cleavage of caspases-8, -9 and PARP. Data in A & C are representative of three experiments. Data in B is presented as means ± S.D. of three independent experiments.