Fig. 4From: β-Lapachone Induces Cell Cycle Arrest and Apoptosis in Human Colon Cancer CellsInduction of apoptosis by β-lapachone in human colon cancer cells. (A) Annexin V staining of SW480, SW620, and DLD1 cells that had been treated with DMSO alone (Con) or 5 µM β-lapachone (β-Lap) for 4 hr and further incubated in drug-free medium for 20 hr. The numbers shown are the percentages of annexin V-positive cells obtained, based on negative controls. (B) Apoptotic analysis of SW620 cells that had been treated with DMSO alone (Con) or 5 µM β-lapachone (β-Lap) for 4 hr and further incubated in drug-free medium for 20 hr. The percentages of apoptotic cells in sub-G1 population are indicated. (C) DNA laddering analysis of SW620 cells that had been treated with 5 µM β-lapachone for 4 hr and incubated in drug-free medium for up to 24 (lane 2), 48 (lane 3), 72 (lane 4), and 96 hr (lane 5). Control cells (Con) were treated with DMSO alone.Back to article page