Fig. 6

LSCs exhibit greater ouabain sensitivity than LPCs regardless of cell cycle status. A Cell cycle distribution of enriched LSCs and LPCs with or without ouabain treatment (30 nM) as analyzed by flow cytometry using PI DNA dye at 0 − 48 h. Data are mean (n = 3). ^**P < 0.01, ^***P < 0.001 versus nontreated LSCs in the same phase of cell cycle; ^##P < 0.01, ^###P < 0.001 versus ouabain-treated LSCs in the same phase of cell cycle; two-sided Student’s t test. B Enriched LSCs and LPCs were sorted according to cell cycle distribution analyzed by flow cytometry using Hoechst 33342 DNA dye into G0/G1, S, and G2/M cells and subsequently treated with ouabain (30 nM) for 48 h. (upper) Percentage of apoptosis in cells obtained from each phase of cell cycle in LSCs (left) and LPCs (right) was determined by Annexin V/7-AAD assay. Data are mean (n = 3). ^**P < 0.01, ^***P < 0.001 versus nontreated control in the same phase of cell cycle in LSCs or LPCs; two-sided Student’s t test. (lower) Relative ouabain sensitivity was calculated from the ratio of apoptosis of treated to nontreated control cells. Data are mean (n = 3). ^*P < 0.05, ^**P < 0.01, ^***P < 0.001 versus nontreated control in G0/G1 cells in LSCs or LPCs; one-way ANOVA with Tukey’s posttest. ^#P < 0.05, ^##P < 0.01, ^###P < 0.001 versus ouabain-treated LSCs in the same phase of cell cycle; two-sided Student’s t test. NS, not significant