Figure 1.

N-Myc downstream-regulated gene 2 (NDRG2) overexpression sensitized U937 cells to As₂O₃ in a caspase-dependent manner. (A) U937-Mock and three U937-NDRG2 lines were incubated with As₂O₃ (2 μM, 24 h). The cells were stained with Annexin V/propidium iodide (PI) and analyzed by flow cytometry. (B) The cells were incubated with As₂O₃ at the indicated time and concentration, and apoptotic cell population was validated with Annexin V/PI staining. (C) Here, 2 μM As₂O₃ was treated in the presence or absence of zVad-fmk (Pan-caspase inhibitor, 50 μM). The apoptotic population was validated with Annexin V/PI staining. (D) U937-Mock and U937-NDRG2 cells treated with As₂O₃ at the indicated dose. The cleavages (Cf) of Caspase3 and PARP were analyzed by immunoblotting. * is non-specific band. ** p < 0.01, *** p < 0.005 determined from t-tests. Data are presented as means ± standard error of the mean (SEM).