Association of circulating miR-125b and survival in patients with osteosarcoma–A single center experience

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.