MicroRNA-194-3p inhibits the metastatic biological behaviors of spinal osteosarcoma cells by the repression of matrix metallopeptidase 9.

: Osteosarcoma is the most common primary malignant bone tumor, but only 3%-5% of cases occur in the spine. Spinal osteosarcoma presents a significant challenge, and most patients die in spite of aggressive surgery. MicroRNAs (miRNAs) are small noncoding RNAs that have a pivotal role in the post-transcriptional regulation of gene expression. The aim of this study was to investigate the role of miR-194-3p and to identify its potential mechanism in spinal osteosarcoma. Here, spinal osteosarcoma tissues showed down-regulated expression of miR-194-3p compared to adjacent non-tumorous tissues. The level of miR-194-3p was negatively correlated with metastasis in patients with spinal osteosarcoma. MiR-194-3p over-expression in spinal osteosarcoma cells significantly inhibited cell migration and invasion in vitro. Furthermore, mechanistic analyses showed that MMP-9 (matrix metallopeptidase 9) is a direct target of miR-194-3p, and the ectopic expression of miR-194-3p inhibits MMP-9 expression by directly binding to the 3'-untranslated region (3'-UTR) of the MMP-9 gene. In summary, our results demonstrate that miR-194-3p suppresses migration and invasion of spinal osteosarcoma cells by targeting MMP-9, indicating miR-194-3p may serve as a promising novel target for spinal osteosarcoma therapy.