Molecular analysis of beta-catenin, caveolin-1, and braf in odontogenic myxomas

Abstract

Objective: The purpose of this investigation was to assess Single Nucleotide Variants (SNVs) and protein expression levels of Caveolin-1, Beta-Catenin, and BRAF in Odontogenic Myxoma (OM).

Methods: Nine formalin-fixed, paraffin-embedded OM tissue specimens were subjected to analysis. Immunohistochemistry was employed to detect protein expression patterns, while Polymerase Chain Reaction (PCR) followed by bidirectional sequencing was conducted to determine the presence of wild-type or mutated gene sequences. Results: Beta-Catenin showed weak positivity in the tumor cells of four samples (44.4%) and in the odontogenic epithelium of one sample (11.1%). Sequencing analysis revealed that the ctnnb1 gene remained wild-type in four cases, whereas five cases exhibited a mutation at codon GAC (G>A), potentially causing an amino acid substitution from aspartic acid to asparagine. Caveolin-1 expression was positive across all nine OM cases. Mutation screening of the caveolin-1 gene identified alterations in two cases at codon CAG (G>C), which may lead to a glutamine-to-histidine change. None of the cases showed immunopositivity for the BRAF-V600E variant, and sequencing confirmed that the braf gene was wild-type in all samples. Conclusions: This study found that OM exhibits weak Beta-Catenin immunoreactivity with frequent mutations in the ctnnb1 gene. Caveolin-1 was ubiquitously expressed, with sporadic mutations that might affect its function. The absence of BRAF-V600E mutations suggests that this pathway is not commonly involved in OM.