Abstract
BACKGROUND: It is known that miRNAs play various roles in malignant tumors. This study is designed to investigate whether miR-125b levels can be used to predict the clinical response of patients with osteosarcoma (OS) to cisplatin-based chemotherapy. METHODS: From January 2010 to July 2015, 82 patients with resectable OS and 56 patients with unresectable OS were enrolled. Blood samples were collected and quantitative real-time PCR was applied to determine miR-125b expression. Clinical data was collected through medical records, and patients were treated according to National Comprehensive Cancer Network guidelines on OS. RESULTS: Our study found that patients with low miR-125b expression had shorter disease-free survival (p<0.001) in the OS group, which was verified by Kaplan-Meier analysis and univariate and multivariate Cox analyses (p<0.001). For patients with unresectable OS, low miR-125b expression was found to be associated with advanced tumor stages (p=0.006). No complete remission was observed, and there were 13 patients with partial remission, 21 with stable disease, and 22 with disease progression. Negative correlation was found between miR-125b expression and response to chemotherapy (p<0.001, r=-0.606). Furthermore, ROC analysis indicated that miR-125b at the cut point of 0.61 yielded an area under the ROC curve of 0.793 (p<0.001, 95% CI: 0.664-0.890) in distinguishing chemotherapy-resistant OS from chemotherapy-sensitive OS, with sensitivity and specificity at 76.9% and 79.1%, respectively. Kaplan-Meier analysis and univariate and multivariate Cox analyses showed that patients with low miR-125b expression suffered shorter overall survival (p=0.014, p=0.024, and p=0.049, respectively). CONCLUSION: Down-regulation of circulating miR-125b might have the potential to predict cisplatin-based chemotherapy resistance and poor prognosis in OS.