The importance of E-cadherin binding partners to evaluate the pathogenicity of E-cadherin missense mutations associated to HDGC

Eur J Hum Genet. 2013 Mar;21(3):301-9. doi: 10.1038/ejhg.2012.159. Epub 2012 Aug 1.

Abstract

In hereditary diffuse gastric cancer (HDGC), CDH1 germline gene alterations are causative events in 30% of the cases. In 20% of HDGC families, CDH1 germline mutations are of the missense type and the mutation carriers constitute a problem in terms of genetic counseling and surveillance. To access the pathogenic relevance of missense mutations, we have previously developed an in vitro method to functionally characterize them. Pathogenic E-cadherin missense mutants fail to aggregate and become more invasive, in comparison with cells expressing the wild-type (WT) protein. Herein, our aim was to develop a complementary method to unravel the pathogenic significance of E-cadherin missense mutations. We used cells stably expressing WT E-cadherin and seven HDGC-associated mutations (five intracellular and two extracellular) and studied by proximity ligation assays (PLA) how these mutants bind to fundamental regulators of E-cadherin function and trafficking. We focused our attention on the interaction with: p120, β-catenin, PIPKIγ and Hakai. We showed that cytoplasmic E-cadherin mutations affect the interaction of one or more binding partners, compromising the E-cadherin stability at the plasma membrane and likely affecting the adhesion complex competence. In the present work, we demonstrated that the study of the interplay between E-cadherin and its binding partners, using PLA, is an easy, rapid, quantitative and highly reproducible technique that can be applied in routine labs to verify the pathogenicity of E-cadherin missense mutants for HDGC diagnosis, especially those located in the intracellular domain of the protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, CD
  • Binding Sites
  • CHO Cells
  • Cadherins / genetics*
  • Cadherins / metabolism*
  • Catenins / metabolism
  • Cricetinae
  • Cytoplasm / genetics
  • Cytoplasm / metabolism
  • Exocytosis / genetics
  • Humans
  • Molecular Biology / methods
  • Mutation, Missense*
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism
  • Stomach Neoplasms / genetics*
  • Stomach Neoplasms / pathology
  • Ubiquitin-Protein Ligases / metabolism
  • beta Catenin / metabolism

Substances

  • Antigens, CD
  • CDH1 protein, human
  • Cadherins
  • Catenins
  • beta Catenin
  • delta catenin
  • CBLL1 protein, human
  • Ubiquitin-Protein Ligases
  • Phosphotransferases (Alcohol Group Acceptor)
  • 1-phosphatidylinositol-4-phosphate 5-kinase