title: Tissue microRNA-126 expression level predicts outcome in human osteosarcoma.
abstract: BACKGROUND
  MicroRNA-126 has been found to be consistently under-expressed in osteosarcoma tissues and cell lines compared with normal bone tissues and normal osteoblast cells, respectively. The purpose of the present study was to detect the expression levels of miR-126 in osteosarcoma patients and to further investigate the clinicopathological, and prognostic value of miR-126.
  
  
  METHODS
  We recruited 122 patients with osteosarcomas from the Department of Orthopedic Surgery, Yantaishan Hospital between May 2008 and April 2013. The expression level of miR-126 was determined by qRT-PCR. Associations between miR-126 expression and various clinicopathological characteristics were analyzed using the χ (2) test. Survival rate was determined with Kaplan-Meier and statistically analyzed with the log-rank method between groups. Survival data were evaluated through multivariate Cox regression analysis.
  
  
  RESULTS
  miR-126 expression was significantly decreased in osteosarcoma tissues compared to adjacent normal bone tissues (2.421 ± 1.250 vs. 6.212 ± 1.843, P = 0.001). We found that low miR-126 expression had significant association with advanced TNM stage (P <0.001), distant metastasis (P <0.001), and higher tumor grade (P = 0.001). Kaplan-Meier survival analysis showed that the miR-126 low-expression group had significantly shorter overall survival time than those with high-expression (log-rank test, P = 0.008). Furthermore, multivariate Cox proportional hazards model analysis showed that miR-126 expression was independently associated with overall survival of patients with osteosarcoma (HR = 3.102, 95 % CI: 1.113-9.023, P = 0.018).
  
  
  CONCLUSIONS
  This is the first study revealing that miR-126 down-expression may be related to the prediction of poor prognosis for osteosarcoma patients, suggesting that miR-126 may serve as a prognostic marker for the optimization of clinical treatments.
authors.affiliation: College of Basic Medicine, Binzhou Medical University, No. 346 Guanhai Road, Laishan District, Yantai, 264003, Shandong, China. binzhou_liuwei@126.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of orthopedics, Yantaishan Hospital, Yantai, 264000, Shandong, China. bz_zhaozhongyuan@126.com.
authors.forename: Zhong-yuan
authors.initials: ZY
authors.lastname: Zhao
authors.affiliation: College of Basic Medicine, Binzhou Medical University, No. 346 Guanhai Road, Laishan District, Yantai, 264003, Shandong, China. bz_shilei@126.com.
authors.forename: Lei
authors.initials: L
authors.lastname: Shi
authors.affiliation: College of Basic Medicine, Binzhou Medical University, No. 346 Guanhai Road, Laishan District, Yantai, 264003, Shandong, China. bz_yuanwendan@126.com.
authors.forename: Wen-dan
authors.initials: WD
authors.lastname: Yuan
mesh_terms: D000293:Adolescent; D014408:Biomarkers, Tumor / Q000235:genetics*; D001859:Bone Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D016009:Chi-Square Distribution; D002681:China; D015536:Down-Regulation; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D015999:Multivariate Analysis; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D012516:Osteosarcoma / Q000235:genetics* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D060888:Real-Time Polymerase Chain Reaction; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; C527111:MIRN126 microRNA, human; D035683:MicroRNAs