MicroRNA-520d-3p inhibits osteosarcoma progression by degradation of Akt1.

OBJECTIVE: To detect the expression of microRNA-520d-3p in osteosarcoma tissue and the function on the osteosarcoma cells proliferation.

PATIENTS AND METHODS: We used qRT-PCR to access microRNA-520d-3p level from 10 cases of osteosarcoma and its adjacent tissues. The osteosarcoma cell lines were screened. The microRNA-520d-3p mimics or inhibitor was transfected into human osteosarcoma cells by liposome method, and the cell proliferation of each group was detected by the CCK8 assay. We used bioinformatics methods to detect and predict the target genes of microRNA-520d-3p. Luciferase reporter assay was utilized to detect the relative luciferase activity between microRNA-520d-3p and Akt1. Meanwhile, after cells were transfected with microRNA-520d-3p mimics, microRNA-520d-3p mimics + OE-Akt1, microRNA-520d-3p inhibitor or microRNA-520d-3p inhibitor + si-Akt1, we detected cell viability using CCK-8 assay, respectively to access the interaction between Akt1 and microRNA-520d-3p.

RESULTS: Lowly expressed microRNA-520d-3p in osteosarcoma tissues was observed in comparison with adjacent tissues. After transfecting with microRNA-520d-3p mimics, the viability of MG63 and U-20S cells decreased, which was higher in cells transfecting microRNA-520d-3p inhibitor. Bioinformatics prediction and dual luciferase reporter assay illustrated that microRNA-520d-3p targeted on Akt1. At the same time, Akt1 expression was higher in osteosarcoma tissues than in adjacent ones, cell proliferation was inhibited after blocking its expression. In addition, after transfected with microRNA-520d-3p mimic, viability of MG63 and U-20S cells decreased, which can be reversed by OE-Akt1. In contrast, the viability of MG63 and U-20S cells increased after transfection with microRNA-520d-3p inhibitor and which were reversed by si-Akt1.

CONCLUSIONS: Lowly expressed microRNA-520d-3p was observed in osteosarcoma; overexpression of microRNA-520d-3p can target Akt1 thus inhibiting proliferation of osteosarcoma cells.