miR-218 significantly decreased the ability of osteosarcoma cells to proliferate. (A) GFP images displaying control, miR-218 and miR-218-sponge expressing stable MG63 cell lines. Scale bar, 100 µm; magnification, ×200. (B) Expression of miR-218 was verified using reverse transcription-quantitative polymerase chain reaction. (C) The cell cycle was analyzed using flow cytometry. (D) The number of proliferating cells in the stable cell lines using the EdU proliferation assay. Scale bar, 100 µm; magnification, ×200. (E) Statistical analysis of the EdU proliferation experiments. (F) Plate colony formation depicting the colony formation ability of the stable cell lines. (G) Statistical analysis of the colony formation experiments. GFP, green fluorescent protein; miR, microRNA. *P<0.05 and **P<0.01 compared with control and miR-218 group; and miR-218 and miR-218-sponge group.