Immunoexpression of Wnt/β-catenin signaling pathway proteins in ameloblastoma and calcifying cystic odontogenic tumor

Abstract

Background: Wnt/β-catenin signaling pathway is essential for the beginning of odontogenesis and may be involved in the development and progression of some odontogenic tumors. Thus, the aim of this study was to comparatively evaluate the immunohistochemical expression of Wnt/β-catenin signaling pathway proteins in a series of AME and CCOT.

Material and methods: Immunohistochemical reactions were performed using antibodies against Wnt1, Wnt5a and β-catenin in 17 cases of solid AME and 6 cases of CCOT.

Results: In the AME group, Wnt1 and Wnt5a were identified in the epithelium in most of the cases, and β-catenin was mainly identified in the cytoplasm of the tumoral cells. In the CCOT group, Wnt1 and Wnt5a were identified in the epithelium and in the ghost cells in almost all the cases, and β-catenin was mainly identified in the cytoplasm and in the nuclei of the tumoral cells.

Conclusions: These results contribute to support the importance of Wnt/β-catenin signaling pathway proteins in AME and CCOT tumorigenesis. The abnormal expression of cytoplasmic and/or nuclear β-catenin appears to contribute to the development of both AME and CCOT. In addition, it is possible that Wnt1 and Wnt5a expression in ghost cells can contribute to its histogenesis in CCOT. Key words:Ameloblastoma, β-catenin, calcifying cystic odontogenic tumor, immunohistochemistry, Wnt.

Figure 1

Histological subtypes of AME and CCOT included in this study (hematoxylin and eosin). A, AME plexiform (original magnification, x200); B, AME follicular (original magnification, x200); C, AME acanthomatous (original magnification, x200); and D, CCOT showing a cystic cavity lined by an ameloblastomatous-like epithelium containing a great amount of ghost cells (hematoxylin and eosin, original magnification, x100)

Figure 2

Immunoexpression of Wnt/β-catenin signaling pathway proteins in AME epithelium (immunoperoxidase). A, Wnt1 identified in a plexiform AME (original magnification, x200); B, Wnt5a identified in a plexiform AME (original magnification, x400); C, β-catenin identified in a follicular AME (original magnification, x100).

Figure 3

Immunoexpression of Wnt/β-catenin signaling pathway proteins in CCOT ameloblastoma-like epithelium and ghost cells (immunoperoxidase). A, Wnt1 identified in the epithelium and ghost cells of a CCOT (original magnification, x200); B, Wnt5a identified in the epithelium and ghost cells of a CCOT (original magnification, x400); C, β-catenin identified only in the epithelium of a CCOT (original magnification, x100).