title: MicroRNA-9 expression is a prognostic biomarker in patients with osteosarcoma.
abstract: BACKGROUND
  The purpose of the present study was to examine the expression levels of microRNA-9 (miR-9) in osteosarcoma tissues and normal bone tissues, and investigate the relationships between miR-9 expression, clinicopathological features and the prognosis of patients with osteosarcoma.
  
  
  METHODS
  The expression levels of miR-9 in osteosarcoma tissues and corresponding non-cancerous tissues were detected using a real-time quantitative assay. Differences in patient survival were determined using the Kaplan-Meier method and a log-rank test. A Cox proportional hazards regression analysis was used for univariate and multivariate analyses of prognostic values.
  
  
  RESULTS
  Compared to non-cancerous bone tissues, the expression levels of miR-9 in osteosarcoma tissues were significantly elevated (P < 0.001). We found that the expression level of miR-9 was significantly associated with tumor size (P = 0.011), clinical stage (P = 0.009) and distant metastasis (P < 0.001). The Kaplan-Meier curve showed that patients with low miR-9 expression survived significantly longer than patients with high miR-9 expression (P = 0.0017). Multivariate analysis suggested that miR-9 expression level (P = 0.002) is an independent prognostic factors for overall survival.
  
  
  CONCLUSIONS
  The findings of our study suggest that increased miR-9 expression has a strong correlation with the aggressive progression of osteosarcoma and its overexpression is a statistically significant risk factor affecting overall survival, suggesting that increased miR-9 expression could be a valuable marker of tumor progression and for prognosis of osteosarcoma.
authors: Shi-hong
authors: SH
authors: Xu
authors: Yong-liang
authors: YL
authors: Yang
authors: Shu-mei
authors: SM
authors: Han
authors: Department of ultrasound diagnosis, Shandong Medical Imaging Research Institute, Shandong University, 324 Jingwu Road, Jinan, Shandong Province 250021, China. dr_wuzonghui@126.com.
authors: Zong-hui
authors: ZH
authors: Wu
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics*; D001859:Bone Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D001842:Bone and Bones / Q000378:metabolism*; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D012516:Osteosarcoma / Q000235:genetics* / Q000401:mortality / Q000556:secondary; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; C541874:MIRN92 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger