Fig. 3

Knockdown of SALL1 in breast cancer cells promotes tumor cell growth, proliferation, and colony formation. a and b Knockdown of SALL1 significantly promoted breast cancer cell growth and proliferation. However, over-expression of SALL1 dramatically inhibited breast cancer cell growth and proliferation. In addition, knockdown or over-expression of SALL1 in normal breast cells MCF12A (control) did not affect cell growth and proliferation. Tumor or normal cells were infected with lentivirus carrying shRNA specific for SALL1 or scramble shRNA control, or transfected with or without plasmids pcDNA3.1-SALL1, and then 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 control shRNA and medium only groups. c and d Knockdown of SALL1 expression in breast cancer cells dramatically increased numbers and sizes of tumor colonies, while over-expression of SALL1 significantly inhibited breast cancer cell colony formation ability. Five thousand per well of tumor cells with the indicated treatments were cultured in soft agar in 6-well plate for 3 weeks and examined for their anchorage-dependent colony formation ability. Results shown in the histogram (in d) are mean ± SD from three independent experiments. **p < 0.01 compared with the control shRNA and medium only groups