Retraction note: Up-regulation of miR-130b expression level and down-regulation of miR-218 serve as potential biomarker in the early detection of human osteosarcoma

BACKGROUND Osteosarcoma (OS) is a primary malignant bone tumor with high morbidity that principally emerges in children and adolescents. MiRNAs regulate a variety of normal physiologic processes and are involved in tumorigenesis and development of multiple malignancies, including OS. This study was aimed to evaluate the clinical significance of miR-130b and miR-218 in osteosarcoma patient. METHODS We utilized quantitative real-time PCR to evaluate the level of miR-130b and miR-218 expressions in OS patients and normal tissues and their relationship with clinicopathological features and survival in OS patients. RESULTS QRT-PCR indicated that miR-130b expression in tumor tissues was strongly elevated than adjacent non-tumor tissues (P < 0.001), while the level of miR-218 expression in osteosarcoma tissues was down-regulated than adjacent non-tumor tissues (P < 0.001). We evaluated the clinical significance of miR-130b and miR-218 in osteosarcoma. Clinical correlation analysis showed that increased expression of miR-130b and decreased expression of miR-218 were significantly associated with advanced tumor stage (x (2) = 6.285, P < 0.009; x (2) = 7.172, P < 0.007), distant metastasis (x (2)  = 5.528; P < 0.001; x (2) = 4.617, P < 0.001) and size of tumor (x (2) = 5.01, P = 0.013; x (2) = 4.271, P = 0.019). CONCLUSIONS Taken together, our data indicated that high miR-130b level and low level of miR-218 are associated with poor clinicopathological characteristics. Furthermore, miR-130b may play a key role in the progression of osteosarcoma.