Fig. 3

Overexpression of RUNX1 promoted NB cell apoptosis, and knockdown of RUNX1 led to suppression of NB apoptosis. a Representative images (left panel) and quantification (right panel) of flow cytometry showing the apoptosis of NB cells (stably transfected with mock, RUNX1, sh-Scb, sh-RUNX1, or sh-RUNX1#2, n = 3) were double stained with an FITC-conjugated anti-Annexin V antibody and PI. The cells in the upper right and lower right quadrants depict late and early apoptosis. b Representative images (left panel) of the mitochondrial membrane potential was evaluated with JC-1 (2 μg/ml) dye. The right panel indicating the ratio of red/green fluorescence was calculated as an indicator of mitochondrial membrane potential. Red fluorescence (Ex/Em 550 nm/600 nm) and green fluorescence (Ex/Em 485 nm/535 nm) were measured using a fluorescence microscope. Scale bar, 100 μm. c-f Real-time RT-PCR and Western blot assays showing the transcript and protein levels of RUNX1, Bax, Bcl-2, and cleaved caspase-3 after stable transfection of NB cells with mock, RUNX1, sh-Scb, sh-RUNX1#1, or sh-RUNX2 and the ratio of Bcl-2/Bax. *P < 0.05 vs. mock or sh-Scb, **P < 0.01 vs. mock or sh-Scb, ***P < 0.001 vs. mock or sh-Scb. Data are shown as mean ± SEM and representative of three independent experiments in panels (a)–(f). Exact P values are specified in Additional file 2: Table S3