title: Increased argonaute 2 expression in gliomas and its association with tumor progression and poor prognosis.
abstract: BACKGROUND
  Previous studies have showed that argonaute 2 is a potential factor related to genesis of several cancers, however, there have been no reports concerning gliomas.
  
  
  METHODS
  Paraffin specimens of 129 brain glioma cases were collected from a hospital affiliated to Binzhou Medical University from January 2008 to July 2013. We examined both argonaute 2 mRNA and protein expression by real-time quantitative PCR (qRT-PCR), Western blot analysis, and immunohistochemistry (IHC). The survival curves of the patients were determined using the Kaplan-Meier method and Cox regression, and the log-rank test was used for statistical evaluations.
  
  
  RESULTS
  Both argonaute 2 mRNA and protein were upregulated in high-grade when compared to low-grade tumor tissues. Multivariate analysis revealed that argonaute 2 protein expression was independently associated with the overall survival (HR=4.587, 95% CI: 3.001-6.993; P=0.002), and that argonaute 2 protein expression and WHO grading were independent prognostic factors for progression-free survival (HR=4.792, 95% CI: 3.993-5.672; P<0.001, and HR=2.109, 95% CI: 1.278-8.229; P=0.039, respectively). Kaplan-Meier analysis with the log-rank test indicated that high argonaute 2 protein expression had a significant impact on overall survival (P=0.0169) and progression-free survival (P=0.0324).
  
  
  CONCLUSIONS
  The present study showed that argonaute 2 expression is up-regulated in gliomas. Argonaute 2 might also serve as a novel prognostic marker.
authors.affiliation: Department of Neurology, Hospital Affiliated to Binzhou medical University, Binzhou, China E-mail : dr_hupeng@126.com.
authors.forename: Bo
authors.initials: B
authors.lastname: Feng
authors.forename: Peng
authors.initials: P
authors.lastname: Hu
authors.forename: Shu-Jun
authors.initials: SJ
authors.lastname: Lu
authors.forename: Jin-Bo
authors.initials: JB
authors.lastname: Chen
authors.forename: Ru-Li
authors.initials: RL
authors.lastname: Ge
mesh_terms: D000328:Adult; D000368:Aged; D060565:Argonaute Proteins / Q000096:biosynthesis*; D014408:Biomarkers, Tumor / Q000235:genetics; D001932:Brain Neoplasms / Q000235:genetics / Q000401:mortality / Q000473:pathology*; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D005910:Glioma / Q000235:genetics / Q000401:mortality / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012333:RNA, Messenger / Q000235:genetics; D014021:Tissue Preservation
chemical_list: C466422:AGO2 protein, human; D060565:Argonaute Proteins; D014408:Biomarkers, Tumor; D012333:RNA, Messenger