MicroRNA-214 functions as an oncogene in human osteosarcoma by targeting TRAF3

Osteosarcoma is a malignant bone tumor with high incidence. The prognosis of osteosarcoma is very poor when it is diagnosed with metastasis. Numerous studies have demonstrated that aberrant expressions of microRNAs are involved in cancer initiation and development. However, the potential role of miR-214 in osteosarcoma remains largely unrevealed. The current study investigated the relationship between the miR-214 and TNF receptor-associated factor 3 (TRAF3) in osteosarcoma tissues and cell lines. We also aimed to evaluate the potential roles of miR-214 on the occurrence and metastasis in osteosarcoma and verify its effect on the regulation of TRAF3.

The miR-214 expression and TRAF3 expression in osteosarcoma tissue samples and cell line were measured using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Followed by transfection assays, transwell assay was conducted to detect the migration and invasion abilities of osteosarcoma cells. Subsequently, Western blotting and luciferase reporter assay were performed in osteosarcoma cells to confirm the target of miR-214.

The results showed that miR-214 expression levels were significantly increased not only in osteosarcoma tissues but also in osteosarcoma cell lines as compared with adjacent normal tissues and matched cell lines, respectively. On the contrary, the TRAF3 expression levels in osteosarcoma tissues and cell lines were frequently decreased compared to the control group. Moreover, TRAF3 was identified as a direct target of miR-214 and the inverse relationship between them was also observed in osteosarcoma tissues. Additionally, we found that miR-214 restoration could significantly promote osteosarcoma cell invasion and migration via targeting TRAF3.

MicroRNA-214 functioned as an oncogene in osteosarcoma via targeting TRAF3, which may provide new insights into osteosarcoma prevention and treatment.