title: miR-21 predicts poor prognosis in patients with osteosarcoma.
abstract: OBJECTIVE
  miR-21 has been demonstrated to play an important role in tumour progression. The aim of the present study was to analyse the correlation between miR-21 expression level and clinicopathologic features, as well as to assess the prognostic significance of miR-21 in osteosarcoma.
  
  
  METHODS
  Eighty-four pairs of osteosarcoma and corresponding non-cancerous bone tissues were obtained, and miR-21 expression levels were detected using quantitative real-time PCR (qRT-PCR). A χ2test was used to assess the relationship between miR-21 expression and clinicopathological features. Overall survival (OS) and disease-free survival (DFS) rates were determined by the Kaplan-Meier method and analysed by the log-rank test. The Cox proportional hazards model was used for multivariate analysis.
  
  
  RESULTS
  qRT-PCR indicated that miR-21 expression in tumour tissues was strongly elevated compared with the adjacent corresponding non-cancerous bone tissue (7.88 ± 1.04 vs. 1.12 ± 0.37, respectively; P < 0.001). High miR-21 expression levels were linked to advanced clinical stage (P = 0.001), distant metastasis (P = 0.001), high tumour grade (P = 0.032) and large-sized tumours (P = 0.013). A higher miR-21 expression was significantly linked to shorter OS and DFS (both P < 0.001). Furthermore, a multivariate analysis confirmed that miR-21 was an independent and significant prognostic factor to predict poor OS and DFS (both P < 0.001).
  
  
  CONCLUSIONS
  Upregulation of miR-21 was associated with poor clinicopathological characteristics. It is used as a marker of poor prognosis in patients with osteosarcoma.
authors.affiliation: a Department of Orthopaedics , The Affiliated Hospital of Qingdao University , Qingdao , China.
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Ren
authors.affiliation: b Department of Surgery , People's Hospital of Rizhao , Rizhao , China.
authors.forename: Yuqin
authors.initials: Y
authors.lastname: Shen
authors.affiliation: c Department of Medcine , People's Hospital of Zhangqiu , Zhangqiu , China.
authors.forename: Shuyun
authors.initials: S
authors.lastname: Zheng
authors.affiliation: a Department of Orthopaedics , The Affiliated Hospital of Qingdao University , Qingdao , China.|b Department of Surgery , People's Hospital of Rizhao , Rizhao , China.
authors.forename: JianYong
authors.initials: J
authors.lastname: Liu
authors.affiliation: b Department of Surgery , People's Hospital of Rizhao , Rizhao , China.|d Department of Orthopaedics , People's Hospital of Weifang , Weifang , China.
authors.forename: Xin
authors.initials: X
authors.lastname: Jiang
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000235:genetics*; D001859:Bone Neoplasms / Q000235:genetics* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D015999:Multivariate Analysis; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D012516:Osteosarcoma / Q000235:genetics* / Q000473:pathology; D011379:Prognosis; D016016:Proportional Hazards Models; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000706:statistics & numerical data; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; C524940:MIRN21 microRNA, human; D035683:MicroRNAs
keywords: Osteosarcoma; miR-21; prognosis