Expression of beta-catenin and Adenomatous Polyposis Coli(APC) Protein in Squamous Cell Carcinoma of the Laryngeal Cancers

Park, Hoon; Kim, Hyo Jin; Park, Jin Gyo; Kim, Dong Wook; Lee, Byung Don; Chang, Hyuck Soon

Abstract

BACKGROUND AND OBJECTIVES
beta-catenin has an essential role in intercellular adhesion and signal transduction. The Adenomatous poliposis coli (APC) protein interacts with beta-catenin in a multi-protein complex to regulate the level of expression of beta-catenin. Mutations in beta-catenin or APC gene can lead to the accumulation of beta-catenin in the cytosol and the nucleus. This study was designed to investigate the expression of APC and beta-catenin in laryngeal cancer. SUBJECTS AND METHOD: Immunohistochemical methods were used to determine the beta-catenin and APC protein expression in 15 laryngeal cancers. Results were correlated with clinicopathological parameters. RESULTS: beta-catenin expression to the plasma membrane was reduced or absent in 11 of 15 cases (73%) of the laryngeal cancers. Cytoplasmic expression of the beta-catenin was seen in 6 out of 15 cases (40%). APC immunoactivity was negative in 5 of 15 (33%) of the laryngeal cancers. One of the six cytoplasmic expressions of the beta-catenin was negative for APC immunoactivity, and one of the five negative for APC immunoactivity was cytoplasmic expression of the beta-catenin. CONCLUSION: There was no correlation between beta-catenin and APC protein in the analysis. This finding suggests that cytoplasmic expression of the beta-catenin resulted not from the APC mutation but from the beta-catenin mutation and abnormal Wnt signal. Only the expression of the beta-catenin in cytoplasm was associated with lymph node metastasis.