Figure 2.

Effects of gefitinib or ATO monotherapy on APL cell apoptosis and proliferation. Gefitinib (5, 10, 20, and 40 μM) (A, B) and ATO (0.5, 1, 2, and 4 μM) (C, D) treatment for 24 h decreased the fraction of apoptotic NB4 and NB4-R2 cells in a concentration-dependent manner, as determined by Annexin V/PI staining and flow cytometry analysis. Proliferation of NB4 (E) and NB4-R2 (F) cells was reduced at gefitinib concentrations higher than twice the ED₅₀ after 24 h of treatment. (G, H) MFI values for NB4 and NB4-R2. Bar graphs show mean ± SD of at least three independent experiments. (*) p < 0.05, (**) p < 0.01, (***) p < 0.001, (****) p < 0.0001 (Kruskal–Wallis test, followed by Dunn’s post hoc test).