p120-catenin expression in human colorectal cancer

Int J Cancer. 1996 Sep 27;68(1):14-20. doi: 10.1002/(SICI)1097-0215(19960927)68:1<14::AID-IJC3>3.0.CO;2-#.

Abstract

Recent data suggest that p120-catenin plays a role in the regulation of functionality of E-cadherin, a protein essential for the establishment and maintenance of cell-cell contacts. Since dysfunction of intercellular adhesiveness is an alteration frequently observed in colon cancer we have studied the expression and distribution of p120-catenin in human colorectal tumors. In normal colon, p120-catenin was observed in the crypt and surface epithelium; the cells showed reactivity both in the membrane and in the cytosol. Thirteen primary tumors were examined for p120-catenin expression: they were graded as uniformly positives (+) (4); heterogeneous (+/-) (6), with a diminished expression, detected mainly in the cytosol; and negatives (-) (3). Although the number of tumors was low, the reduction in p120-catenin correlated with a larger size of the tumors (p = 0.038). Association of p120-catenin to the cytoskeleton was also determined in 5 tumors by detergent extraction and Western blot; this analysis shows that lack of reactivity in the membrane was accompanied by absence of p120-catenin in the cytoskeleton-associated fraction. Analysis of E-cadherin was performed in order to compare the distribution of this protein and p120-catenin. Although no complete correlation was found between the expression of both proteins (p = 0.077), our results showed that alterations in the level or distribution of p120-catenin were accompanied by lack of E-cadherin reactivity in the membrane, whereas absence of p120-catenin in the cytoskeleton fraction was associated with important decreases in the amount of E-cadherin in this same fraction. These results show that alterations in p120-catenin levels are a common event in colorectal tumors, and suggest that the distribution of this protein and E-cadherin is coordinately regulated.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal
  • Blotting, Western
  • Cadherins / analysis
  • Catenins
  • Cell Adhesion Molecules / analysis*
  • Cell Membrane / chemistry
  • Colorectal Neoplasms / chemistry*
  • Colorectal Neoplasms / ultrastructure
  • Cytoskeleton / chemistry
  • Fluorescent Antibody Technique
  • Humans
  • Immunohistochemistry
  • Phosphoproteins / analysis*

Substances

  • Antibodies, Monoclonal
  • Cadherins
  • Catenins
  • Cell Adhesion Molecules
  • Phosphoproteins
  • delta catenin