Figure 2

Overexpression of miR-9 suppresses tumor cell growth in vitro. (A) In pcDNA3/pri-miR-9 transfected MGC803 cells, the mature miR-9 level was significantly increased. (B) MGC803 cells were transfected with pri-miR-9, control vector or pri-miR-9 with pcDNA3/NF-κB1, and cell growth activity was determined at 72 h post-transfection by MTT assay. Values are means ± SD of three duplications and the relative cell growth activity is shown (*P < 0.05). (C) MGC803 cells were transfected with gradually increasing concentrations of pri-miR-9 from 0 ng/μl to 15 ng/μl (final concentration) and the dose-dependent anti-proliferative effects were detected by MTT assay. (D) Cell independent growth activity was detected by colony formation assay. MGC803 cells were transfected with pri-miR-9, control vector or pri-miR-9 with pcDNA3/NF-κB1, and then seeded in 12-well plates. The number of colonies was counted from the 6th day after seeding. The colony formation rate was calculated and is shown. (E) The validity of NF-κB1 ectopic expression vector pcDNA3/NF-κB1 was confirmed by Western blot assay. MGC803 cells were transfected with pri-miR-9 as well as pcDNA3/NF-κB1 or control vector. The NF-κB1 protein level was detected by Western blot assay. GAPDH protein was regarded as endogenous normalizer and the relative NF-κB1 protein quantity is shown.