Serum levels of microRNA-133b and microRNA-206 expression predict prognosis in patients with osteosarcoma

The aim of the present study was to investigate whether the aberrant expression of microRNA (miR)-133b and miR-206 can be used as potential prognostic markers of human osteosarcoma. Quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis was performed to detect the expression levels of miR-133b and miR-206 in 100 pairs of osteosarcoma tissues and matched noncancerous bone tissues, and serum samples from 100 patients with osteosarcoma as well as in serum samples from 100 healthy controls. As a result, expression levels of miR-133b and miR-206 were both significantly decreased in osteosarcoma tissues and patients' sera (both P<0.001). Then, the downregulation of miR-133b and miR-206 both more frequently occurred in osteosarcoma patients with high tumor grade (both P=0.01), positive metastasis (both P<0.001) and recurrence (both P<0.001). Moreover, the patients with low miR-133b expression and low miR-206 expression both had shorter overall survival (OS, both P<0.001) and disease-free survival (DFS, both P<0.001) than those with high expressions. Of note, the OS and DFS of patients with combined low expression of miR-133b and miR-206 (miR-133b-low/miR-206-low) were the shortest (both P<0.001). Furthermore, low miR-133b expression, low miR-206 expression and conjoined expression of miR-133b/miR-206 were all independent prognostic factors for OS and DFS of osteosarcoma patients. Collectively, the aberrant expression of miR-133b and miR-206 may be implicated in tumorigenesis and tumor progression of osteosarcoma. More interestingly, detection of serum miR-133b and miR-206 expression could be further developed as novel, non-invasive and efficient markers for prognosis in patients with osteosarcomas.