MiR-20a promoted growth of GC cell lines. SGC7901 or MKN45 cells were transfected with miR-20a precursor/inhibitor or the corresponding control, respectively. (A) At 24, 48, 36, 72, or 96 h after transfection, MTT assay was performed to examine SGC7901 proliferation; (B) MTT assay of MKN45 cells; (C) Representative results of colony formation assay in SGC7901 and MKN45 cells transfected with miR-20a precursor/inhibitor or the corresponding control, respectively; (D) The apoptosis of SGC7901 and MKN45 cells after miR-20a precursor transfection; (E) The proliferation index of SGC7901 and MKN45 cells transfected with miR-20a precursor; (F) qRT-PCR for miR-20a was performed in SGC7901 and MKN45 cells transfected with miR-20a precursor/inhibitor or the corresponding control, respectively. The data represented at least four measurements. *p < 0.05, **p < 0.01 compared with control.