Caspase 3/7 activities and apoptosis levels in proliferating and differentiating C2C12 myoblasts following NDRG2 and 3A-NDRG2 overexpression. (A) Caspase 3/7 activities in myoblasts at P2, P3 and D0. Cells were infected with vector alone (black bars), NDRG2 (white bars) or 3A-NDRG2 (gray bars). Luminescence as a reflection of activity is represented as relative light units (RLU), n = 6 per sample. (B) Percentage of TUNEL positive myoblasts (10 fields of view counted per treatment), and (C) apoptotic DNA laddering gel at P3. Lanes: L, DNA 1 kb ladder; +C, positive control apoptotic U937 cells; V, vector; N, NDRG2; and 3A, 3A-NDRG2. (D) Immunoblots of total and cleaved PARP, total and cleaved caspase 3, Bcl-2, Bcl-xL and Bax proteins at P3, and (E), at or D0 for Bcl-2, Bcl-xL and Bax proteins (n = 3 per treatment). β-Actin protein indicates protein levels loaded. Data are mean of three independent experiments. ***P < 0.001 and **P < 0.01 compared to vector; ###P < 0.001 and #P < 0.05 compared to NDRG2.