الفهرس | Only 14 pages are availabe for public view |
Abstract The combination of clinically aggressive behavior, certain histopathological characteristics, and understanding of genetic nature changed the classification of what was known as an odontogenic keratocyst to keratocystic odontogenic tumor. Growth Factor Receptor-bound protein 2 (Grb2) is a key molecule in intracellular signal transduction, linking activated cell surface receptors to downstream targets (as it is located in the nucleus, cytoplasm, endosome, golgi apparatus) by binding to specific phosphotyrosine-containing and proline-rich sequence motifs. HER family includes four epidermal growth factor receptors, HER1, HER2, HER3, and HER4. They are also called as ErbB-1, ErbB-2, ErbB-3, and ErbB-4. These are transmembrane tyrosine kinase receptors and their functions include regulation of cell growth, cell survival, adhesion, migration, differentiation and cellular responses. The immunohistochemical results of the present study showed positive nuclear Her2 staining seen mainly in the suprabasal and granular layers of the epithelial lining of KCOTs. The immunohistochemical results of the present study showed that Grb2 immunoreactivity was seen in both cytoplasm and nucleus of the epithelial cells of KCOT. This Grb2 expression pattern might explain the neoplastic nature of KCOT as it was found that In human cancers, Grb2-mediated signaling (such as EGFR pathway) are often overexpressed, correlating with poor prognosis. Statistical analysis of the present study revealed that there is positive correlation between the HER2 and Grb2 expression in KCOT (R=0.931). The relationship between Grb2 and HER2 (erbB2) expression can be explained by the fact that Grb2 and HER2 are both located at chromosome 17q. |