MiR-630 inhibits cell proliferation by inhibiting CDC7-mediated DNA synthesis. A549 cells were transfected with scrambled small interfering RNA (siRNA) (control), miR-630 mimic and miR-630 inhibitor for 48 and 72 h. (a) Western blotting for CDC7, MCM2 and phospho-MCM2. β-Actin was used as a loading control. (b) Flow cytometric analysis of BrdU-positive cells. After 48 and 72 h transfection, cells were labeled with 50 μM BrdU for 1 h before collection. Samples were stained with anti-BrdU FITC antibody and PI, and analyzed by flow cytometry. BrdU-positive cells were included in the gate region. (c) Relative amount of BrdU-positive cells in the gate region compared with total cells in (b) experiments. Data are presented as mean±S.D. (n=3); 48 h: *P=0.0396, ##P=0.0054; 72 h: **P=0.0037, #P=0.0171. (d) MTS assay showed the survival of A549 cells transfected with miR-630 mimic or inhibitor for 48 h. Data are presented as mean±S.D. (n=3); **P=0.0026 and #P=0.0223