Purpose: Aberrant accumulation of beta-catenin plays an important role in a variety of human neoplasms. In this study we analyzed the somatic mutations of the beta-catenin gene and the immunohistochemical localization of beta-catenin and cyclin D1 in invasive ductal breast cancer.
Materials and methods: We investigated 65 human invasive ductal breast cancer samples for somatic mutations in the exons 3, 4, 5 and 6 of beta-catenin gene (N-terminal region) by the combined use of polymerase chain reaction (PCR), single-strand conformation polymorphism (SSCP) and sequencing. Sample tissues were also analyzed using beta-catenin and cyclin D1 immunocytochemistry staining.
Results: No beta-catenin mutation was detected in any of the tumor samples. Accumulation of aberrant beta-catenin protein in cellular compartments in the same breast cancer samples was confirmed with a related experiment by immunocytochemical methods.
Conclusion: Our results suggest that genetic defects in beta-catenin is not common in invasive ductal breast cancers, whereas mutations in other components of the Wnt signaling pathway should be considered.