FAK, paxillin, and PI3K in ameloblastoma and adenomatoid odontogenic tumor

Objective Integrins function to bind cells to extracellular matrix in tissues, which triggers downstream signaling cascades that are important in cell survival, proliferation, cytokine activation, and cytoskeleton reorganization. These processes also play significant roles in neoplasms. This work aimed to investigate the pattern of expression of FAK, paxillin, and PI3K in ameloblastoma and adenomatoid odontogenic tumor (AOT). Materials and methods Immunohistochemistry was used to study FAK, paxillin, and PI3K in 45 ameloblastomas (32 conventional, 12 unicystic, and 1 peripheral types), 7 AOTs, and two developing human teeth. Results Weak expression of FAK was seen in all AOT cases, while ameloblastoma had varying expression patterns, mostly strong to weak. The pattern of expression of paxillin and PI3K was relatively similar in both tumor types. In the dental germ, FAK and paxillin stained all the enamel organ components, while PI3K stained strongly the inner enamel epithelium. Stromal expression of FAK was not found to be useful in differentiating between tumors or tumor classes. Conclusion The expression of the proteins in the enamel organ suggests that their signaling may be important in odontogenesis. While some ameloblastomas strongly expressed FAK, all cases of AOT had weak signals suggesting low presence and phosphorylating activity of FAK in the latter.

Automated summary

Integrins serve the purpose of binding cells to the extracellular matrix in tissues, triggering downstream signaling cascades important for cell survival, proliferation, cytokine activation, and cytoskeleton reorganization. This study investigated the expression patterns of FAK, paxillin, and PI3K in ameloblastoma and adenomatoid odontogenic tumor (AOT), finding different expression patterns of FAK and relatively similar patterns of paxillin and PI3K in both tumor types. The expression of these proteins in the enamel organ suggests their potential importance in odontogenesis, with strong FAK expression in some ameloblastomas and weak signals in all AOT cases.