Differential expression of cytoplasmic carbonic anhydrases, CA I and II, and membrane-associated isozymes, CA IX and XII, in normal mucosa of large intestine and in colorectal tumors

Dig Dis Sci. 2001 Oct;46(10):2179-86. doi: 10.1023/a:1011910931210.


This study compares the localization of carbonic anhydrase isozymes (CA) I and II and that of IX and XII in normal large intestine and in colorectal tumors. Immunohistochemical studies were performed on 69 colorectal lesions. While the normal mucosa of the large intestine showed high expression for CA I and II, the intensity of the immunostaining for both isozymes decreased in benign lesions and was very weak in malignant tumors. The reciprocal pattern of expression observed for these cytoplasmic isozymes and transmembrane CA IX and XII in intestinal tissue specimens supports the suggestion that CA IX and XII may be functionally involved in tumor progression to malignancy and/or in invasion. By contrast, while CA I and II are prominent in normal colorectal mucosa, where they play a role in regulation of pH homeostasis and water and ion transport, loss of expression of these cytoplasmic isozymes consistently accompanies progression to malignant transformation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenocarcinoma / metabolism*
  • Adenomatous Polyps / metabolism
  • Antigens, Neoplasm*
  • Carbonic Anhydrase I / metabolism
  • Carbonic Anhydrase II / metabolism
  • Carbonic Anhydrase IX
  • Carbonic Anhydrases / metabolism
  • Colorectal Neoplasms / metabolism*
  • Humans
  • Immunohistochemistry
  • Intestinal Mucosa / metabolism*
  • Neoplasm Proteins / metabolism


  • Antigens, Neoplasm
  • Neoplasm Proteins
  • Carbonic Anhydrase I
  • Carbonic Anhydrase II
  • CA9 protein, human
  • Carbonic Anhydrase IX
  • Carbonic Anhydrases