title: Differences in gene expression profiles and carcinogenesis pathways between colon and rectal cancer.
abstract: OBJECTIVE
  Colon cancer is more common in the USA and Europe than that in China, for reasons that are unclear. The aim of this study was to investigate the differences in gene expression profiles and carcinogenesis pathways between colon and rectal cancer.
  
  
  METHODS
  Expression profiling of primary tumor tissues from 12 colon and 12 rectal cancers was performed using oligonucleotide microarray analysis. All samples were strictly matched by clinical features. Bioinformatic analyses such as the Kyoto Encyclopedia of Genes and Genomes were used to identify genes and pathways specifically associated with colon or rectal cancers.
  
  
  RESULTS
  A total of 824 genes were differentially expressed in colon and rectal cancers. All differential gene interactions in the Signal-Net were analyzed. More genes were differentially expressed and included in the Signal-Net for rectal than colon cancer. Of the genes differentially expressed between colon and rectal cancer, S100P, the Reg family, ACTN1, CAMK2G and ACAT1 were the most significantly altered. Genes involved in the cell cycle pathway were present in rectal and colon cancers, but were more important in rectal cancer. The p53 and metabolic signaling pathways were significantly different in colon and rectal cancers. Gene expression profiles differed between colon and rectal cancer, with metabolic pathways being more important in rectal cancer.
  
  
  CONCLUSIONS
  The oncogenesis of rectal cancer may be more complex than that of colon cancer. Some genes could be new biomarkers for distinguishing between these two cancers.
authors.affiliation: Department of Gastroenterology, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China.
authors.forename: Jing Nan
authors.initials: JN
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Zhao
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.forename: Bin
authors.initials: B
authors.lastname: Wu
authors.forename: Hong
authors.initials: H
authors.lastname: Yang
authors.forename: Heng Hui
authors.initials: HH
authors.lastname: Zhang
authors.forename: Jia Ming
authors.initials: JM
authors.lastname: Qian
mesh_terms: D000101:Acetyl-CoA C-Acetyltransferase / Q000235:genetics; D000185:Actinin / Q000235:genetics; D000368:Aged; D002135:Calcium-Binding Proteins / Q000235:genetics; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000235:genetics; D003110:Colonic Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000503:physiopathology; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics; D012004:Rectal Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000503:physiopathology; D015398:Signal Transduction / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics
chemical_list: C526905:ACTN1 protein, human; D002135:Calcium-Binding Proteins; D009363:Neoplasm Proteins; C103003:S100P protein, human; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D000185:Actinin; C506639:ACAT1 protein, human; D000101:Acetyl-CoA C-Acetyltransferase; C517662:CAMK2G protein, human; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2