Figure 1. miR-542-3p was down-regulated in osteosarcoma tissues and cells. (A) The results of qRT-PCR showed that miR-542-3p was low expressed in osteosarcoma tissues. **P<0.01 compared to the peri-tumorous group; (B) The expression of miR-542-3p in cell lines 143B and U-2OS were lower than that in normal human osteoblastic cell line hFOB1.19. **P<0.01 compared to the hFOB1.19 group; (C) The miR-542-3p mimics and inhibitor had high transfection efficiency.