Figure 4. IB-DNQ induces apoptosis of Vari068 ALDH⁺ CSCs and ATN224 enhances IB-DNQ-mediated apoptosis in SUM149 BC cells expressing low/modest levels of NQO1.

A-B, Vari068 cells treated with IB-DNQ for 20h were examined by flow cytometry to assess early and late apoptotic cells (A), or fixed and examined by ALDH1A3 and TUNEL dual labeling fluorescent microscopy (B) and % of TUNEL⁺ over total or ALDH1A3⁺ cells were scored in 3 different areas. C-D, SUM149 cells treated with IB-DNQ alone or together with ATN224 (5 μM) for 20h were examined by flow cytometry to detect early and late apoptotic cells (C), or fixed and examined by ALDH1A3 and TUNEL dual labeling (D), and % of TUNEL⁺ over total or ALDH1A3⁺ cells were scored in 3 different areas. ****: P < 0.0001 vs. Vehicle. n=3, one-way ANOVA for A and C and unpaired student’s t-test for B and D. Scale bar: 50 μm.