MicroRNA-212 Inhibits Osteosarcoma Cells Proliferation and Invasion by DownRegulation of Sox4

Background: Multiple MicroRNAs (miRNAs) have been identified in the development and progression of osteosarcoma. However, the expression and roles of miR-212 in osteosarcoma remain largely undefined. Methods: Real-time PCR assays were used to detect the expression of miR-212 in human osteosarcoma tissues. MiR-212 mimics were introduced into MG63 and U2OS cells. Bioinformatic prediction was used to identify the potential targets of miR-212. Protein expression analysis, luciferase assays and rescue assays were used to confirm the substrate of miR-212. Results: miR-212 was significantly down-regulated in human osteosarcoma tissues, compared with adjacent normal tissues. Introduction of miR-212 mimics into MG63 and U2OS cells inhibited cell proliferation and invasion. Besides, miR-212 overexpression could also inhibit tumor growth in the nude mice. Additionally, bioinformatic prediction suggested that the sex-determining region Y-box 4 (Sox4) is a target gene of miR-212. Sox4 inhibition phenocopied the roles of miR-212, while restored expression of Sox4 dampened miR-212-mediated suppression of tumor progression. Conclusion: The miR-212/Sox4 interaction plays an important role of in the osteosarcoma progression. Copyright (C) 2014 S. Karger AG, Basel