MicroRNA-128 inhibits EMT of human osteosarcoma cells by directly targeting integrin α2

Deregulated expression of miRNAs contributes to the development of osteosarcoma. The present study was to evaluate the level of miR-128 and integrin alpha 2 (ITGA2) in osteosarcoma tissues and cells. We further investigated the molecular mechanisms of miR-128 and ITGA2 in osteosarcoma cell lines. In the present study, we found that miR-128 expression was down-regulated in osteosarcoma tissues and MG-63, U2OS, and SAOS-2 cells (all p < 0.001). By contrast, ITGA2 was up-regulated. Furthermore, we found that miR-128 overexpression suppressed cell migration and invasion of MG-63 cells. Mechanically, miR-128 overexpression inhibited epithelial-mesenchymal transition (EMT) of MG-63 cells. Importantly, we identified that the 3'-untranslated region (3'-UTR) of ITGA2 was a direct target of miR-128. Luciferase reporter assays confirmed that miR-128 binding to the 3'-UTR regions of ITGA2 inhibited the expression of ITGA2 in MG-63 cells. At the same time, overexpressed ITGA2 also reversed EMT inhibited by miR-128. In conclusion, this study suggested that high miR-128 expression suppressed osteosarcoma cell migration, invasion, and EMT development through targeting ITGA2, which may be recommended as a therapeutic target for osteosarcoma.