Low miR-491-5p is an unfavorable prognostic marker for osteosarcoma

Osteosarcoma is one of the most leading causes of cancer-related mortality in children and adolescence around the world. The aim of this study was to determine the clinical value of miR-491-5p in osteosarcoma. Quantitative real-time PCR was used to evaluate miR-491-5p level in the tissue/serum samples from patients with osteosarcoma. Then the clinical significance of tissue/serum miR-491-5p was analyzed. Our resulted showed that the expression level of miR-491-5p was significantly decreased in cancer tissues compared to adjacent normal tissues. Serum miR-491-5p was downregulated in osteosarcoma patients and was able to differentiate the osteosarcoma patients from healthy volunteers. In addition, tissue and serum miR-491-5p was highly correlated. Tissue/ serum miR-491-5p was significantly associated with various clinicopathological parameters such as distant metastasis, clinical stage and histological grade. Moreover, osteosarcoma patients with lower levels of tissue/serum miR-491-5p suffered worse 5 year overall/disease free survival. Finally, both tissue and serum miR-491-5p were independent prognostic factors for osteosarcoma. This study demonstrated that miR-491-5p had strong potential to serve as a noninvasive biomarker for osteosarcoma diagnosis and predicting prognosis.