Osteosarcoma is the most common non-hematological primary bony
malignancy in children and young adults with
tumor metastasis being a common event at diagnosis. Understanding the pathogenesis of metastatic
osteosarcoma may help identify potential therapeutic targets. In this study, we found that the level of microRNA-645 (miR-645) in
osteosarcoma tumor tissues was significantly increased compared with their paired non-tumorous tissues, and was associated with histologic grade, TNM staging, lymph
metastasis and distant
metastasis. Knockdown of miR-645 caused a remarkable inhibition of migration of
osteosarcoma U2OS cells. Furthermore, miR-645 inhibited NME2 (
nucleoside diphosphate kinase 2) expression through directly binding to its
3' untranslated region. In human
osteosarcoma tissues, we also found that NME2 was significantly decreased in
tumor tissues, and its level was negatively correlated with miR-645. In addition, silencing NME2 attenuated the decreased cell migration by knockdown of miR-645, suggesting that it was involved in the miR-645 induced cell migration of
osteosarcoma cells. Taken together, we found that miR-645 was up-regulated in
osteosarcoma tissues and could promote
osteosarcoma cell migration through directly inhibiting the
tumor suppressor NME2. Our data provide novel insight into the role of miR-645 in
osteosarcoma and indicate that miR-645 might be a potential therapeutic target of
osteosarcoma.