Figure 5. Induction of apoptosis by Gomisin M2. (A) After 48 h of incubation with Gomisin M2 at the indicated concentrations, cell apoptosis was assessed by flow cytometry after staining with propidium iodide (PI) and Annexin V. Doxorubicin was used as positive control. (B) The quantitative data of panel a (MDA-MB-231 cells). The percentages of Annexin V-positive cells are shown. ** p < 0.01. (C) The quantitative data of panel a (HCC1806 cells). (D) Western blot analysis of apoptotic hallmarks, treated with different doses of Gomisin M2 for 48 h.