Molecular genetic criteria for oral mucosal epithelial malignization

Introduction. When examining the oral mucosa (OM) in the presence of an inflammatory process, the initial signs of malignancy are not always visible. Amid an inflammatory infiltrate, benign changes such as epithelial hyperplasia (EH), epithelial dysplasia (ED) of varying severity, and squamous cell carcinoma (SCC) can be hidden. The aim of the paper was to study the proliferative activity of epithelial cells of the OM, TERT expression, and amplification of telomerase TERC gene in the development of epithelial hyper-plasia, dysplasia, and SCC. Materials and methods. We divided 60 patients into four groups: Group 1 with EH (n=16, 26.6%); Group 2 with low-grade epithelial dysplasia (LGED) [n=16, 26.6%]; Group 3 with high-grade epithelial dysplasia (HGED) [n=13, 21.6%]; and Group 4 with SCC (n=15, 25%). IHC and histological studies were carried out using standard methods; expression to Ki-67 protein and telomerase activity were evaluated. The FISH method was used with LSP TERC and CCP3 DNA probes. Results. High-cell proliferation and telomerase activity were revealed by IHC study in all groups. Amplification of TERC RNA site in chromosome 3 by FISH in Group 1 was almost absent and showed a 2:2 signal ratio in 1.3% of cases; in other groups, the amplification of TERC gene was positive: in groups 2, 3, and 4 it was in 83.9%, 97.3%, and 89.8% of cases, respectively. Conclusion. Amplification of TERC site signals in chromosome 3 is detected during malignization which may be the main criterion for early diagnosis of malignization of OM epithelium. © 2023, MDV Group. All rights reserved.