[1279] Investigation of Beta-Catenin Gene and Protein in Ameloblastoma

Ludmila De Faro Valverde, Caroline Brandi Schlaepfer-Sales, Marcilei Eliza Cavichiolli Buim, De Aquino Flavia Calo Xavier, Luciana Maria Pedreira Ramalho, Jean Nunes Dos Santos, Fernando Augusto Soares, Eduardo Antonio Goncalves Ramos, Clarissa Araujo Gurgel. Federal University of Bahia, Salvador, Bahia, Brazil; Oswaldo Cruz Foundation-Gonçalo Moniz Research Center, Salvador, Bahia, Brazil; AC Camargo Hospital, São Paulo, Brazil

Background: Ameloblastoma (AB) is a benign odontogenic tumor with agressive behaviour and high recurrence rates. Wingless Type signaling pathway (WNT) is involved in the development of dental organ and plays a key role by regulating the β-catenin protein proteolysis, which is involved in cell adhesion and proliferation. Thus, WNT signaling pathway in dental development prompted us to study β-catenin gene expression and protein in AB.
Design: Quantitative PCR was performed in 11 cases of AB and 3 cases of non-neoplastic mucosa (NNM) using SYBRTM Green PCR Master Mix to assess the expression of β-catenin gene. Analysis was perfomed according to Pfaffl (2001). Immunohistochemistry for β-catenin protein was performed using EnVisionTM System. Immunostaining was evaluated according to location (membrane, nuclear and cytoplasmic) and proportion of positive cells (0, <5%, 1+, 5-25%; 2+, 25-50%, 3+, 50-75%; 4+,> 75%).
Results: A higher expression of β-catenin gene was found in AB compared to NNM, specially in unicystic AB type (p = 0.0173). In NNM, β -catenin protein was observed in membrane of all epitelial cells. Membrane and nuclear immunostainings were more evident in unicystic AB comparing to solid tumor (p = 0.0004 and p=0.047, respectively).
Conclusions: The expression of β-catenin gene in ABs suggests the participation of the WNT pathway in the development of this tumor. In solid AB, the loss of membrane expression β-catenin, indicates that this protein could contribute to the greater invasiveness of this histological subtype of AB. In addition, in unicystic AB, the function of cell adhesion appears to be retained, while the nuclear staining of β-catenin suggests that this molecule could be involved in tumor growth.
Category: Head & Neck

Tuesday, March 5, 2013 9:30 AM

Poster Session III # 140, Tuesday Morning


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