Cytoplasmic/nuclear expression without mutation of exon 3 of the beta-catenin gene is frequent in the development of the neoplasm of the uterine cervix.

OBJECTIVE: The dual function of beta-catenin (e.g., as an intermediate protein between adherence junctions and the microfilaments, and as a mediator of the Wnt signaling pathway) is currently known. Stabilization of beta-catenin and subsequent activation of the Wnt signaling pathway are involved in the development of some malignancies. We analyzed the immunohistochemical localization of beta-catenin and the somatic mutation of exon 3 of the beta-catenin gene in the malignant phenotype of the uterine cervix.
METHODS: Immunohistochemical localization of beta-catenin and mutation of exon 3 of the beta-catenin gene were analyzed in 38 precancerous lesions and 43 cancerous lesions.
RESULTS: In normal cervix, beta-catenin was observed around the plasma membrane of the cells in the basal and parabasal layers of the epithelium. The frequency of cytoplasmic/nuclear beta-catenin expression correlated with a high histological grade of cervical intraepithelial neoplasia. Among invasive carcinomas, 11 (73%) of 15 samples showed cytoplasmic/nuclear localization to variable extents. A mutational analysis showed that mutation occurred in 7 of 68 specimens. Six cases with mutations revealed cytoplasmic/nuclear beta-catenin expression, though 32 (84%) of the 38 samples showing cytoplasmic/nuclear beta-catenin expression were not associated with the mutation.
CONCLUSION: These results indicate that cytoplasmic/nuclear expression of beta-catenin is associated with the malignant phenotype of the cervix, but the contribution of mutation of the beta-catenin gene is limited. Copyright 2001 Academic Press.