title: Relationship between let-7a and gastric mucosa cancerization and its significance.
abstract: OBJECTIVE
  To investigate let-7a expression and analyze the correlation between let-7a and progression of gastric mucosa cancerization.
  
  
  METHODS
  The tissue microarray was constructed previously in 52 cases of human gastric carcinoma, 17 cases of chronic atrophic gastritis (atypical hyperplasia) and 11 cases of normal gastric tissue, and tissue microarrays combined with in situ hybridization were used to detect the expression of let-7a.
  
  
  RESULTS
  The positive rates of let-7a in normal gastric tissue, chronic atrophic gastritis and gastric carcinoma were 90.9%, 88.2% and 86.5%, respectively, without significant differences among the groups (P > 0.05). However, an intense signal of let-7a was observed in gastric epithelial cells, whereas a less intense signal was found in gastric atypical hyperplasia epithelial cells and a weak signal in gastric carcinoma epithelial cells. The expression of let-7a decreased along with the progression of gastric mucosa cancerization (P < 0.05). In the group of gastric carcinoma, the expression of let-7a was even significantly lower in gastric carcinomas with lymph node metastasis than in those without metastasis (P < 0.05).
  
  
  CONCLUSIONS
  Gastric carcinoma has relatively lower expression of let-7a. Reduced let-7a may be a fundamental factor in the formation and lymph node metastasis of gastric carcinoma.
authors.affiliation: Department of General Surgery, The Second Hospital of Jiaxing, Jiaxing 314000, Zhejiang Province, China.
authors.forename: Yi-Min
authors.initials: YM
authors.lastname: Zhu
authors.forename: Zheng-Xiang
authors.initials: ZX
authors.lastname: Zhong
authors.forename: Zhi-Ming
authors.initials: ZM
authors.lastname: Liu
mesh_terms: D016022:Case-Control Studies; D005753:Gastric Mucosa / Q000378:metabolism; D005757:Gastritis, Atrophic / Q000235:genetics / Q000378:metabolism; D006801:Humans; D017403:In Situ Hybridization; D008207:Lymphatic Metastasis / Q000235:genetics; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism*; D012334:RNA, Neoplasm / Q000235:genetics* / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000235:genetics* / Q000378:metabolism*; D046888:Tissue Array Analysis
chemical_list: D035683:MicroRNAs; D012334:RNA, Neoplasm; C487931:mirnlet7 microRNA, human