Differential expression of aquaporin 8 in human colonic epithelial cells and colorectal tumors

BMC Physiol. 2001;1:1. doi: 10.1186/1472-6793-1-1. Epub 2001 Jan 23.


Background: The gene expression pattern in tumor cells differs from that in corresponding normal cells. In order to identify differentially expressed genes in colorectal tumors and normal colorectal epithelium, a differential display experiment was used to compare RNA expression in normal and tumor tissue samples.

Results: One gene fragment was expressed only in normal tissue and not, or to a much lesser extent, in the adenomas, carcinomas and cancer cell lines. The isolated gene fragment was identical to Aquaporin 8 (AQP8), a water channel protein. In situ hybridization demonstrated that AQP8 was expressed in the cells facing the lumen in the normal colonic epithelium.

Conclusion: Our result suggests that the expression of AQP8 is a marker of normal proliferating colonic epithelial cells and suggest these cells to be involved in fluid transport in the colon.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoma / genetics
  • Adenoma / metabolism
  • Aquaporins / genetics
  • Aquaporins / metabolism*
  • Carcinoma / genetics
  • Carcinoma / metabolism
  • Cell Line, Tumor
  • Colon / cytology
  • Colon / metabolism*
  • Colorectal Neoplasms / genetics
  • Colorectal Neoplasms / metabolism*
  • Epithelial Cells / metabolism
  • Humans
  • In Situ Hybridization
  • Intestinal Mucosa / chemistry
  • Intestinal Mucosa / metabolism*
  • Ion Channels*
  • RNA, Messenger / analysis
  • RNA, Messenger / metabolism
  • Transcription, Genetic
  • Tumor Cells, Cultured


  • Aquaporins
  • Ion Channels
  • RNA, Messenger
  • aquaporin 8