title: MMP-9 expression in peripheral blood mononuclear cells and the association with clinicopathological features and prognosis of nasopharyngeal carcinoma.
abstract: BACKGROUND
  Matrix metalloproteinase-9 (MMP-9) shows significant involvement with cancer invasion and therefore has prognostic significance. Tumor tissues from nasopharyngeal carcinoma (NPC) patients are not easy to access, and peripheral blood mononuclear cells (PBMC) are a valuable alternative. This study compared the expression levels of MMP-9 in PBMCs from NPC patients and healthy controls and evaluated the potential as a prognostic biomarker for NPC patients.
  
  
  METHODS
  MMP-9 mRNA concentrations in PBMCs from 146 NPC patients and 110 healthy controls were measured using quantitative real-time PCR. Differences in MMP-9 expression between NPC patients and controls were evaluated using non-parametric tests, and the effects of different clinical characteristics on MMP-9 expression were also analyzed. The Kaplan-Meier test and Cox regression model were used to explore the association between MMP-9 expression and overall survival of NPC patients.
  
  
  RESULTS
  MMP-9 mRNA levels in PBMCs were significantly higher in NPC patients than in healthy controls (p<0.001). Increased MMP-9 expression was associated with the following clinical characteristics: advanced clinical stage (p<0.001), T stage (p=0.016), N stage (p=0.002), histology type (p=0.037), and poor overall survival (p=0.049).
  
  
  CONCLUSIONS
  MMP-9 mRNA expression in PBMCs from NPC patients is increased and associated with the clinical characteristics and overall survival. It supports the belief that MMP-9 may contribute to the progression of NPC.
authors.affiliation: State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou, PR China.
authors.forename: Jian-Rong
authors.initials: JR
authors.lastname: He
authors.forename: Han
authors.initials: H
authors.lastname: Qin
authors.forename: Ze-Feng
authors.initials: ZF
authors.lastname: Ren
authors.forename: Cui
authors.initials: C
authors.lastname: Cui
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Dharshana
authors.initials: D
authors.lastname: Ranatunga
authors.forename: Yi-Xin
authors.initials: YX
authors.lastname: Zeng
authors.forename: Wei-Hua
authors.initials: WH
authors.lastname: Jia
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma; D016022:Case-Control Studies; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000235:genetics*; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000097:blood / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015996:Survival Rate; D055815:Young Adult
chemical_list: D012333:RNA, Messenger; D020780:Matrix Metalloproteinase 9