MiR-598: A tumor suppressor with biomarker significance in osteosarcoma.

AIMS: Osteosarcoma is the most frequent primary malignant bone tumor in children and adolescents. Identifying specific and sensitive biomarkers is beneficial to early detection and improvement of life qualities and overall survival rates of osteosarcoma patients.

MATERIALS AND METHODS: Realtime PCR was used to detect the expression of miR-598. CCK-8 assay was employed to detect the proliferation of osteosarcoma cells, while transwell assays were used to examine the migration and invasion. Tumor xenograft experiments were performed to test the in vivo malignancy of osteosarcoma cells. Co-culture experiment was used to study the relationship between osteosarcoma cells and osteoblast. Realtime PCR, Western Blotting and luciferase report assays were conducted for the target genes analysis.

KEY FINDINGS: Using a cohort of 20 cases of osteosarcoma and paired adjacent tissue samples, we found that miR-598 expression was decreased in osteosarcoma tissues and serum, as well as the osteosarcoma cell lines. Over expression of miR-598 suppressed the proliferation, migration, and invasion of osteosarcoma cells, while inhibition of miR-598 expression stimulated the proliferation, migration, and invasion. However, MiR-598 had no effect on osteosarcoma cell apoptosis. Data from nude mice further demonstrated the inhibitory role of miR-598 in osteosarcoma progression in vivo. Mechanically, miR-598 played its role by modulating osteoblastic differentiation in the microenvironment and targeting PDGFB and MET.

SIGNIFICANCE: Our findings enrich the knowledge of miR-598 in osteosarcoma progression, and reveal miR-598 as a promising diagnostic, prognostic, therapeutic biomarker for osteosarcoma.