MiR-204-5p promotes apoptosis and inhibits migration of osteosarcoma via targeting EBF2.

Osteosarcoma is one of the most malignant cancer adolescents and young adults and metastatic osteosarcoma is a huge life threat with a 5-year survival lower than 20%. However, the mechanisms through which localized osteosarcoma turned metastatic are not fully understood. Here, we studied the role of miR-204-5p in osteosarcoma and found that miR-204-5p is downregulated in both osteosarcoma patients and osteosarcoma cell lines. In addition, overexpression of miR-204-5p resulted in increase of osteosarcoma cell apoptosis and decrease of osteosarcoma cell migration and invasion. Besides, our in vivo xenograft data showed strong inhibitory role of miR-204-5p in tumor growth. Importantly, our data showed that miR-204-5p regulates the mRNA stability of Early B Cell Factor 2 (EBF2), a crucial regulator in osteosarcoma apoptosis, by directly binding to 3' UTR of EBF2. Besides, our data further revealed that overexpressed EBF2 inhibited apoptosis and facilitated migration and invasion of osteosarcoma cells. Additionally, EBF2 overexpression rescued the phenotype caused by miR-204-5p.Our data indicated that miR-204-5p is an anti-oncogenic miRNA in osteosarcoma which functions through inhibiting oncogenic transcription factor EBF2. These results provided new therapeutic targets for metastatic osteosarcoma and insights into molecular regulation of EBF2.