FIGURE 2.

Tumor cells are more sensitive to archazolid. A and B, SKBR3 cells and the nontumor epithelial cell line MCF10A were treated with different concentrations of archazolid for (A) 48 h, and apoptosis was measured via propidium iodide staining and flow cytometry or (B) 72 h and proliferation was measured by crystal violet staining. C, for analysis of colony formation cells were treated with 2.5 nm archazolid for 24 h, trypsinized, and seeded at low density for 7 days, stained with crystal violet, and colonies were counted. Colonies of untreated control cells were set as 100%. D, for V-ATPase inhibition cells were treated for 2 h or left untreated (Co), and acidity of lysosomes was visualized using a pH-dependent LysoTracker and confocal microscopy. One representative picture of three independent sets is shown. E, growth inhibition of tumor and nontumor cells after archazolid treatment for 72 h and increasing doses was analyzed by CellTiter-Blue assay. *, p ≤ 0.001, Student's t test.