Downregulation of miR-185 and upregulation of miR-218 expression may be potential diagnostic and prognostic biomarkers of human chondrosarcoma.

Increasing evidence has confirmed that dysregulation of microRNAs (miRNAs) can contribute to the progression and metastasis of human tumors. Chondrosarcoma is the most common primary malignant bone tumor in adults and has no effective systemic treatment, and patients with this disease have poor survival. Thus, it is important to find new diagnostic markers and improve treatment options. In the current study, we are interested to examine the role of miR-185 and miR-218 expression in patients with chondrosarcoma using real-time PCR. Moreover, the association of the two miRNAs with clinicopathological features and prognosis was evaluated. Survival and Cox proportional hazards analyses were performed to find the association of miR-185 expression and miR-218 levels with prognosis in the patients. Our results indicated that the miR-185 expression was significantly downexpressed in clinical chondrosarcoma bone tissues compared with adjacent normal tissues (P = 0.001). MiR-218 expression level was increased in clinical chondrosarcoma bone tissue than those adjacent normal tissues (P = 0.001). Decreased expression of miR-185 showed remarkable correlation with advanced tumor stage (P = 0.019), tumor grade (P < 0.001), and distant metastasis (P = 0.001). Moreover, high expression of miR-218 was strongly correlated with advanced tumor stage (P = 0.014), tumor grade (P < 0.001), and distant metastasis (P = 0.002). Kaplan-Meier survival analysis revealed that the low miR-185 expression group and the high miR-218 expression group had remarkably shorter overall survival (log-rank test P = 0.007, P = 0.004). The multivariate Cox proportional hazards model indicated that decreased expression of miR-185 and increased expression of miR-218 (P = 0.017, P = 0.012), advanced tumor stage (P = 0.006, P = 0.012), tumor grade (P = 0.032, P = 0.016), and distant metastasis (P = 0.004, P = 0.015) were independently related to overall survival in patients with chondrosarcoma. In conclusion, downregulation of miR-185 and upregulation of miR-218 can be associated with progression of chondrosarcoma and also both of them may act as tumor suppressor genes in chondrosarcoma.