Fig. 2
Over-expression of SALL1 in breast cancer cells inhibits tumor cell growth and proliferation, and promotes cell cycle arrest. a and b Transfection of SALL1 but not SALL4 significantly inhibited breast cancer cell growth and proliferation. However, over-expression of SALL1 in B16F0 melanoma cells and normal MCF12A cells (controls) did not affect cell growth and proliferation. Cells transfected with or without plasmids pcDNA3.1-SALL1, pcDNA3.1-SALL4, and pcDNA3.1, were cultured at a starting number of 2 × 104/well in 24 wells (a), or 1 × 104/well in 96-well plates (b). Cell growth was evaluated at different time points using by counting cell number (in a), and cell proliferation was determined using [3H]-thymidine assays (in b). Data are mean ± SD from three independent experiments with similar results. **p < 0.01 compared with the vector control group. c The suppression of breast cancer cell proliferation and growth mediated by SALL1 expression is not due to cell apoptosis. Transfected breast cancer and melanoma cells were cultured for additional 72 h. Apoptosis in transfected tumor cells was analyzed after staining with PE-labeled Annexin V and 7-AAD. Data shown are representative of three independent experiments with similar results. d SALL1 transfection in MCF-7, MDA-MB-231 and E0771 cells, but not in melanoma B16F0 cells significantly promoted cancer cell cycle arrest in S phase and decrease in G0/G1 phase. Cell treatment was the same as in (c). Cell cycle distribution in tumor cells was analyzed after incubation with 10 μg/ml propidium iodide and 100 μg/ml RNase A. B16F0 melanoma cells served as a control. Data are representative of three independent experiments with similar results