Fig. 2

Cell death induced by β-lapachone displays either apoptotic or necrotic features. Human ovary, breast, and colon cancer cells were treated with β-lapachone 0 µM (DMSO), 4 µM, or 8 µM for 4 hr, followed by incubation in drug-free medium for 20 hr before they were subjected to flow-cytometric analysis after staining with propidium iodide for quantitating the sub-G1 fraction (A), or for the analysis of externalization of phosphatidylserine (B), as measured by Annexin V staining. □, DU 145; ○, A2780; ■, DLD; ●, MCF, +21MT.