Immunohistochemical detection of beta-catenin and adenomatous polyposis coli in ameloblastomas.
BACKGROUND
To clarify the roles of the Wnt signaling pathway in oncogenesis and cytodifferentiation of odontogenic tumors, expression of beta-catenin and adenomatous polyposis coli (APC) was analyzed in ameloblastomas as well as in tooth germs.


METHODS
Tissue specimens of 10 tooth germs, 40 benign ameloblastomas, and five malignant ameloblastomas were examined immunohistochemically with the use of antibodies against beta-catenin and APC.


RESULTS
Immunohistochemical reactivity for beta-catenin was detected in the cell membrane and cytoplasm of most odontogenic epithelial cells in tooth germs and ameloblastomas. Nuclear beta-catenin expression was recognized in nine of 40 ameloblastomas and two of five malignant ameloblastomas, but not in tooth germs. APC was evidently expressed in odontogenic epithelial cells neighboring the basement membrane in tooth germs and ameloblastomas, and the reactivity was significantly lower in benign and malignant ameloblastomas than in tooth germs. Follicular ameloblastomas and acanthomatous ameloblastomas tended to show high nuclear beta-catenin expression and low APC reactivity, as compared with other ameloblastoma variants.


CONCLUSIONS
Expression of beta-catenin and APC in tooth germs and ameloblastomas suggests that aberration of the Wnt signaling pathway might play a role in oncogenesis and cytodifferentiation of odontogenic epithelium via deregulation of cell proliferation.
Kumamoto
H
H
Division of Oral Pathology, Department of Oral Medicine and Surgery, Tohoku University Graduate School of Dentistry, Sendai, Japan. kumamoto@mail.tains.tohoku.ac.jp
Ooya
K
K
D025601:Adenomatous Polyposis Coli Protein / Q000032:analysis*; D000564:Ameloblastoma / Q000737:chemistry*; D000818:Animals; D003598:Cytoskeletal Proteins / Q000032:analysis*; D006801:Humans; D007150:Immunohistochemistry; D007573:Jaw Neoplasms / Q000737:chemistry*; D051379:Mice; D018709:Statistics, Nonparametric; D014083:Tooth Germ / Q000737:chemistry; D015534:Trans-Activators / Q000032:analysis*; D051176:beta Catenin
D025601:Adenomatous Polyposis Coli Protein; C495270:CTNNB1 protein, human; C495267:CTNNB1 protein, mouse; D003598:Cytoskeletal Proteins; D015534:Trans-Activators; D051176:beta Catenin