miR-196 acts as a tumor suppressor in osteosarcoma by targeting HOXA9

Abnormal expression of microRNAs (miRNAs) has been found in most cancer types. Therefore, the discovery of miRNAs could help us to understand the mechanism of tumor initiation and development. The purpose of this study was to investigate the significance of miR-196 in osteosarcoma (OS) and to identify its target genes. We found miR-196 expression was significantly reduced in OS tissues and cell lines (Saos-2 and MG-63) as compared to normal tissues and cell line. The OS cell line proliferation and migration abilities were inhibited by miR-196 overexpression but promoted by miR-196 downregulation in vitro. Moreover, we revealed that miR-196 could bind to the 3'-untranslated region (3'-UTR) of homeobox A9 (HOXA9) and inhibit HOXA9 expression in OS cell lines. Furthermore, knockdown the expression of HOXA9 resulted in decreased proliferation and migration which was similar to that observed with miR-196 overexpression in OS cell lines. In summary, miR-196 inhibits proliferation and migration of OS cell lines through regulating HOXA9, which might be a useful target for OS treatment.