title: Upregulation of neutrophil gelatinase-associated lipocalin in oesophageal squamous cell carcinoma: significant correlation with cell differentiation and tumour invasion.
abstract: BACKGROUND
  Neutrophil gelatinase-associated lipocalin (NGAL) is a member of the lipocalin family. Recently, an elevated NGAL expression was reported in several types of cancers. However, the characteristics of NGAL expression in oesophageal squamous cell carcinoma (ESCC) are still unknown.
  
  
  OBJECTIVE
  To demonstrate the role of NGAL in ESCC.
  
  
  METHODS
  NGAL expression in 81 paraffin sections, including ESCC, normal mucosa, simple hyperplasia and dysplasia, and in 73 fresh specimens of ESCC was analysed by immunohistochemistry, western blot and gelatin zymography.
  
  
  RESULTS
  On immunohistochemical study, ESCC showed a diverse staining pattern for NGAL. However, only a weak positive signal was present within a restricted cytoplasmic area in the normal oesophageal epithelium. In dysplasia, altered NGAL expression could also be observed. On western blot study, NGAL expression level was found to be significantly higher in ESCC than in normal mucosa (p=0.030), and to be positively correlated with cell differentiation. However, no significant association was observed between NGAL expression and cell proliferation. In addition, the enzymic activity of the NGAL/matrix metalloproteinase 9 complex was much higher in ESCC than in normal mucosa, and was significantly correlated with the depth of tumour invasion in zymography analysis (p=0.006).
  
  
  CONCLUSIONS
  The findings suggest that NGAL is involved in the differentiation pathway and invasive progression of ESCC.
authors.affiliation: Department of Biochemistry and Molecular Biology, Medical College of Shantou University, Shantou,Guangdong Province, People's Republic of China.
authors.forename: Haihua
authors.initials: H
authors.lastname: Zhang
authors.forename: Liyan
authors.initials: L
authors.lastname: Xu
authors.forename: Dawei
authors.initials: D
authors.lastname: Xiao
authors.forename: Jianjun
authors.initials: J
authors.lastname: Xie
authors.forename: Hongmei
authors.initials: H
authors.lastname: Zeng
authors.forename: Zhaoyang
authors.initials: Z
authors.lastname: Wang
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Zhang
authors.forename: Yongdong
authors.initials: Y
authors.lastname: Niu
authors.forename: Zhongying
authors.initials: Z
authors.lastname: Shen
authors.forename: Jinghui
authors.initials: J
authors.lastname: Shen
authors.forename: Xuan
authors.initials: X
authors.lastname: Wu
authors.forename: Enmin
authors.initials: E
authors.lastname: Li
mesh_terms: D000209:Acute-Phase Proteins / Q000378:metabolism*; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D002454:Cell Differentiation; D004848:Epithelium / Q000378:metabolism; D004938:Esophageal Neoplasms / Q000378:metabolism* / Q000473:pathology; D004947:Esophagus / Q000473:pathology; D005260:Female; D006801:Humans; D006965:Hyperplasia / Q000378:metabolism; D007124:Immunoenzyme Techniques; D000071068:Lipocalin-2; D054834:Lipocalins; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000378:metabolism; D009367:Neoplasm Staging; D011230:Precancerous Conditions / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D000209:Acute-Phase Proteins; D014408:Biomarkers, Tumor; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D009363:Neoplasm Proteins; D018809:Proliferating Cell Nuclear Antigen; D011518:Proto-Oncogene Proteins; D020780:Matrix Metalloproteinase 9