Elevated expression of microRNA-19a predicts a poor prognosis in patients with osteosarcoma

MicroRNA (miR)-19a, a member of the miR-17-92 cluster, functions as an oncomiRNA in multiple kinds of cancers. However, its involvement in human osteosarcomas remains unclear. In this study, to analyze the expression pattern of miR-19a and to investigate its clinical implication in human osteosarcomas, quantitative reverse-transcription polymerase chain reaction was performed to detect expression levels of miR-19a in 166 self-pairs of osteosarcoma and noncancerous bone tissues. Associations between miR-19a expression and various clinicopathological parameters and patients' prognosis of osteosarcomas were further evaluated. As a results, miR-19a expression in osteosarcoma tissues was significantly higher than that in corresponding noncancerous bone tissues (P<0.001). Osteosarcoma patients with high miR-19a expression more frequently had large tumor size (P=0.03), advanced clinical stage (P=0.01), positive distant metastasis (P=0.008) and poor response to chemotherapy (P=0.01) than those with low miR-19a expression. Additionally, kaplan-Meier analysis showed that both overall and disease-free survivals of osteosarcoma patients with high miR-19a expression were shorter than those with low miR-19a expression (both P<0.001). Further multivariate analysis identified miR-19a expression as an independent prognostic factor for both overall (P=0.001) and disease-free (P=0.006) survivals. In conclusion, the aberrant expression of miR-19a may play a crucial role in development and progression of human osteosarcomas. MiR-19a may act as a novel prognostic marker for patients with this malignancy.