LAUSR

MicroRNAs (miRNAs) are key regulators in the development and progression of osteosarcoma (OS). Based on our previous microarray data, we found that miR-335 expression was downregulated in OS tissue relative to normal tissue. Herein, we further found that miR-335 was downregulated in OS cell lines relative to the osteoblastic cell line hFOB 1.19. Further functional experiments found that upregulation of miR-335 suppressed the proliferation, invasion and migration of OS cells in vitro and tumor growth and lung metastasis in vivo. In addition, the expression of a total of 750 mRNAs was decreased upon the upregulation of miR-335, and SNIP1 was found to be the direct target of miR-335. Restoration of SNIP1 expression attenuated the suppressive effect of miR-335 on OS cells. Additionally, miR-335 suppressed the mRNA and protein expression of SNIP1, MMP-2, and MMP-7 in vitro and in vivo. MiR-335 also suppressed c-Myc and NFκb p65 in vitro and in vivo. In conclusion, our data suggest that miR-335 plays a significant role in the tumorigenesis and metastasis of OS and may serve as a therapeutic target for OS treatment.