Prognostic value of the microRNA-29 family in patients with primary osteosarcomas

The aim of this study was to facilitate and deepen the understanding of the associations of the microRNA-29 (miR-29) family with tumor progression and patients' prognosis of primary osteosarcoma. We examined expression levels of miR-29a, miR-29b, and miR-29c in tumor tissues and patients' sera of 80 cases of primary osteosarcomas by quantitative real-time reverse transcriptase-polymerase chain reaction. The correlations of their serum levels with clinicopathological characteristics and patient prognosis were also analyzed. The expression levels of miR-29a, miR-29b, and miR-29c in osteosarcoma tissues and patients' sera were all significantly higher than those in normal controls (all P < 0.05). The serum levels of miR-29a and miR-29b in the patients with higher tumor grade (both P = 0.01), positive metastasis (both P = 0.006), and positive recurrence (both P = 0.006) were both markedly higher than those with lower tumor grade, negative metastasis, and negative recurrence. According to the survival analysis of 80 osteosarcoma patients, cases in the miR-29a-high and miR-29b-high-expression groups both showed shorter overall survival (OS, both P < 0.001) and disease-free survival (DFS, both P < 0.001). Furthermore, the serum levels of miR-29a and miR-29b were both independent prognostic factors for OS and DFS of osteosarcoma patients. However, high miR-29c level was not related to any clinicopathological characteristics and patient prognosis of osteosarcomas (P > 0.05). The findings from the present study reveal that the miR-29 family may play crucial roles in the development and progression of human osteosarcoma. In particular, the serum levels of miR-29a and miR-29b may well estimate the prognosis of patients with this malignancy.