title: Gene expression profile differences in gastric cancer, pericancerous epithelium and normal gastric mucosa by gene chip.
abstract: OBJECTIVE
  To study the difference of gene expression in gastric cancer (T), pericancerous epithelium (P) and normal tissue of gastric mucosa (C), and to screen an associated novel gene in early gastric carcinogenesis by oligonucleotide microarray.
  
  
  METHODS
  U133A (Affymetrix, Santa Clara, CA) gene chip was used to detect the gene expression profile difference in T, P and C, respectively. Bioinformatics was used to analyze the detected results.
  
  
  RESULTS
  When gastric cancer was compared with normal gastric mucosa, 766 genes were found, with a difference of more than four times in expression levels. Of the 766 genes, 530 were up-regulated (Signal Log Ratio (SLR) >2), and 236 were down-regulated (SLR<-2). When pericancerous epithelium was compared with normal gastric mucosa, 64 genes were found, with a difference of more than four times in expression levels. Of the 64 genes, 50 were up-regulated (SLR>2), and 14 were down-regulated (SLR<-2). Compared with normal gastric mucosa, a total of 143 genes with a difference in expression levels (more than four times, either in cancer or in pericancerous epithelium) were found in gastric cancer (T) and pericancerous epithelium (P). Of the 143 genes, 108 were up-regulated (SLR>2), and 35 were down-regulated (SLR<-2).
  
  
  CONCLUSIONS
  To apply a gene chip could find 143 genes associated with the genes of gastric cancer in pericancerous epithelium, although there were no pathological changes in the tissue slices. More interesting, six genes of pericancerous epithelium were up-regulated in comparison with genes of gastric cancer and three genes were down-regulated in comparison with genes of gastric cancer. It is suggested that these genes may be related to the carcinogenesis and development of early gastric cancer.
authors.affiliation: Zhejiang Cancer Research Institute, No. 38 Guangji Road, Hangzhou 310022, Zhejiang Province, China. yuchuanding@hotmail.com
authors.forename: Chuan-Ding
authors.initials: CD
authors.lastname: Yu
authors.forename: Shen-Hua
authors.initials: SH
authors.lastname: Xu
authors.forename: Hang-Zhou
authors.initials: HZ
authors.lastname: Mou
authors.forename: Zhi-Ming
authors.initials: ZM
authors.lastname: Jiang
authors.forename: Chi-Hong
authors.initials: CH
authors.lastname: Zhu
authors.forename: Xiang-Lin
authors.initials: XL
authors.lastname: Liu
mesh_terms: D004848:Epithelium / Q000502:physiology; D005260:Female; D005753:Gastric Mucosa / Q000502:physiology*; D020869:Gene Expression Profiling / Q000379:methods*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D011230:Precancerous Conditions / Q000235:genetics*; D013274:Stomach Neoplasms / Q000235:genetics*