title: Clinical significance of matrix metalloproteinase-9 expression in esophageal squamous cell carcinoma.
abstract: OBJECTIVE
  To evaluate the expression of matrix metalloproteinase-9 (MMP-9) and its clinical significance in esophageal squamous cell carcinoma (ESCC).
  
  
  METHODS
  The expression of MMP-9 in 208 cases of ESCC was detected by immunohistochemistry (IHC) and its clinical significance in ESCC especially the relationship with the clinicopathological parameters was analyzed.
  
  
  RESULTS
  The percentage of positive cases for MMP-9 detected by IHC was 49.0%. MMP-9 was mainly expressed in the cytoplasm of cancer cells especially in the invasive front. Only weak expression was detected in the stromal cells and no expression in non-cancerous mucosa. The expression of MMP-9 was positively correlated with poorer differentiation (P = 0.001<0.01), existence of vessel permeation (P = 0.027<0.05) and lymph node metastasis (P = 0.027<0.05).
  
  
  CONCLUSIONS
  The expression of MMP-9 correlates with the cancer cell differentiation, vessel permeation and lymph node metastasis. It may be a novel biomarker for the diagnosis and treatment of ESCC.
authors.affiliation: Department of Thoracic Surgery, Peking University School of Oncology, Beijing Cancer Hospital, Beijing 100036, China.
authors.forename: Zhen-Dong
authors.initials: ZD
authors.lastname: Gu
authors.forename: Ke-Neng
authors.initials: KN
authors.lastname: Chen
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Jin
authors.initials: J
authors.lastname: Gu
authors.forename: Ji-You
authors.initials: JY
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000556:secondary; D002454:Cell Differentiation; D004938:Esophageal Neoplasms / Q000235:genetics* / Q000473:pathology; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000235:genetics*; D008875:Middle Aged; D011379:Prognosis
chemical_list: D014408:Biomarkers, Tumor; D020780:Matrix Metalloproteinase 9