Accumulation of beta-catenin protein, mutations in exon-3 of the beta-catenin gene and a loss of heterozygosity of 5q22 in solid pseudopapillary tumor of the pancreas

J Surg Oncol. 2006 Oct 1;94(5):418-25. doi: 10.1002/jso.20509.

Abstract

Background: Solid pseudopapillary tumors (SPT) of the pancreas are neoplasms with a low malignant potential. The molecular events contributing to the pathogenesis of SPTs are still unknown.

Objectives: This study was intended to help better understand the early steps of human SPT development.

Methods: We microdissected 20 SPTs and normal pancreatic tissue. In addition, we examined the DNA from each SPT for mutations in exon-3 of beta-catenin and loss of heterozygosity (LOH) on 9 chromosome arms using 10 microsatellite markers. Immunohistochemical staining for beta-catenin was performed.

Results: Activating mutations between codons 32 and 37 of beta-catenin exon-3 were present in 16 cases (80%). Allelic loss on chromosome 5q22.1 was present in 10 cases (55.5%), while no allelic loss was found on chromosomes 1p, 6q, 9p, 9q, 11p, 11q, 17p, or 22q. Nuclear accumulation of beta-catenin was found in 20 cases (100%).

Conclusion: Mutations in exon-3 of the beta-catenin gene, nuclear accumulation of beta-catenin, and LOH on chromosome 5q22.1 in SPT tissue suggest that these mutations are involved in SPT tumorigenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Carcinoma, Papillary / genetics*
  • Carcinoma, Papillary / pathology
  • Child
  • Chromosomes, Human, Pair 5 / genetics*
  • Cystadenoma, Papillary
  • DNA Mutational Analysis
  • Exons / genetics*
  • Female
  • Gene Expression
  • Humans
  • Immunohistochemistry
  • Loss of Heterozygosity*
  • Male
  • Microsatellite Repeats
  • Middle Aged
  • Mutation*
  • Pancreatic Neoplasms / genetics*
  • Pancreatic Neoplasms / pathology
  • beta Catenin / genetics*

Substances

  • beta Catenin