title: Clinicopathological significance of altered metallothionein 2A expression in gastric cancer according to Lauren's classification.
abstract: BACKGROUND
  Dysregulated metallothionein 2A (MT2A) has been implicated in carcinogenesis. The purpose of this study was to investigate the expression of MT2A in gastric cancer (GC) and its correlation with prognosis.
  
  
  METHODS
  Reverse transcription-polymerase chain reaction and real-time polymerase chain reaction were used to detect the mRNA expression of MT2A in 12 GC cell lines, normal gastric epithelial GES-1 cells, and 36 GC and adjacent normal tissues. MT2A protein expression was determined in 258 GC tissues and 171 adjacent normal tissues by immunohistochemistry.
  
  
  RESULTS
  MT2A mRNA expression was lower in GC cells and primary tumors than in GES-1 cells and adjacent normal tissues, respectively. High protein expression of MT2A was present in 130 of 171 normal tissues (76.0%) and in 56 of 258 GC tissues (21.7%; P < 0.001). MT2A protein expression was higher in well/moderately differentiated GC (22/54; 40.7%) than in poorly differentiated GC (34/204; 16.7%; P < 0.001). Moreover, the protein expression of MT2A was lower in diffuse-type GC (6/82; 7.3%) than in intestinal-type GC (50/176; 28.4%; P = 0.0001). Importantly, MT2A expression was an independent prognostic factor for GC, and decreased MT2A expression was associated with poor clinical outcome (P < 0.001). The expression status of MT2A could predict prognosis in intestinal and diffuse-type GCs.
  
  
  CONCLUSIONS
  Expression status of MT2A might be a useful prognostic biomarker for GC, especially when used in combination with Lauren's classification.
authors.affiliation: Department of Gastroenterology & Hepatology, Chinese People's Liberation Army General Hospital, Beijing, China.
authors.forename: Yuan-ming
authors.initials: YM
authors.lastname: Pan
authors.forename: Rui
authors.initials: R
authors.lastname: Xing
authors.forename: Jian-tao
authors.initials: JT
authors.lastname: Cui
authors.forename: Wen-mei
authors.initials: WM
authors.lastname: Li
authors.forename: You-yong
authors.initials: YY
authors.lastname: Lü
mesh_terms: D000328:Adult; D000368:Aged; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008668:Metallothionein / Q000032:analysis* / Q000235:genetics; D035683:MicroRNAs / Q000032:analysis; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D013274:Stomach Neoplasms / Q000737:chemistry / Q000145:classification / Q000473:pathology*
chemical_list: C552430:MIRN23a microRNA, human; C491053:MT2A protein, human; D035683:MicroRNAs; D008668:Metallothionein