title: Possible involvement of leptin and leptin receptor in developing gastric adenocarcinoma.
abstract: OBJECTIVE
  To investigate the expression of leptin and leptin receptor (ob-R) in intestinal-type gastric cancer and precancerous lesions, and to explore the possible mechanism and role of the leptin system in developing intestinal-type gastric adenocarcinoma.
  
  
  METHODS
  Immunohistochemistry was performed to examine the expression of leptin and leptin receptor in archival samples of gastric adenocarcinoma and preneoplastic lesions, including intestinal metaplasia and mild to severe gastric epithelial dysplasia. Positive staining was identified and percentage of positive staining was graded.
  
  
  RESULTS
  Dual expression of leptin and leptin receptor were detected in 80% (16/20) intestinal metaplasia, 86.3% (25/30) mild gastric epithelial dysplasia, 86.7% (26/30) moderate gastric epithelial dysplasia, 93.3% (28/30) severe gastric epithelial dysplasia, 91.3% (55/60) intestinal-type gastric adenocarcinoma and 30.0% (9/30) diffuse-type gastric carcinoma. The percentage of dual expression of leptin and leptin receptor in intestinal-type gastric adenocarcinoma was significantly higher than that in diffuse-type gastric adenocarcinoma (c2 = 37.022, P<0.01).
  
  
  CONCLUSIONS
  Our results indicate the presence of an autocrine loop of leptin system in the development of intestinal-type gastric adenocarcinoma.
authors.affiliation: Department of Gastroenterology, Renmin Hospital, Wuhan University, Wuhan 430060, Hubei Province, China. airman-zhao@tom.com
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.forename: Zhi-Xiang
authors.initials: ZX
authors.lastname: Shen
authors.forename: He-Sheng
authors.initials: HS
authors.lastname: Luo
authors.forename: Lei
authors.initials: L
authors.lastname: Shen
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry / Q000209:etiology*; D006801:Humans; D007150:Immunohistochemistry; D020738:Leptin / Q000032:analysis / Q000502:physiology*; D020935:MAP Kinase Signaling System; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology; D011230:Precancerous Conditions / Q000737:chemistry / Q000209:etiology; D011956:Receptors, Cell Surface / Q000032:analysis / Q000502:physiology*; D054411:Receptors, Leptin; D013274:Stomach Neoplasms / Q000737:chemistry / Q000209:etiology*
chemical_list: D020738:Leptin; D019869:Phosphatidylinositol 3-Kinases; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin; C515448:LEPR protein, human