Abstract: Objective: To analyse the expression of microRNA-93 (miR-93) in osteosarcoma and investigate the effect of miR-93 on the proliferation and cell cycle in osteosarcoma cell lines. Methods: To detect the expression of miR-93 in 38 pairs of osteosarcoma and cartilaginous tissues using TagMan MGB Real-time PCR. To construct the miR-93 overexpressed vector and synthesis the miR-93 antisense nucleotide sequence. Then they were transfected into osteosarcoma cell lines U2-OS and MG-63. Cell proliferation was detected by MTT assay and cell cycle was detected by flow cytometry. Results: 65.8%（25/38）of miR-93 was overexpressed in osteosarcoma compared to cartilaginous tissue (P<0.05). Overexpression of miR-93 could promote the growth of osteosarcoma cell lines and delay the cell cycle in S phase. The reduction of miR-93 could inhibit the growth of osteosarcoma cell lines and delay the cell cycle in G0/G1 phase. Conclusions: miR-93 was overexpressed in osteosarcoma and miR-93 could regulate the growth of osteosarcoma cells via mediating the transition of G1/S phase, which may become a targeted gene of osteosarcoma.

Key words: osteosarcoma, microRNAs, cell proliferation, cell cycle, transfection, miR-93