Features of CCND1 and EGFR gene amplification and their correspondence with the expression of CYCLIN D1 and EGFR proteins in the tongue squamous cell carcinoma

The purpose of the study: Evaluation tumor cell number with CCND1 and EGFR gene amplification and its correlation with Cyclin D1 and EGFR protein expression in squamous cell carcinoma of the tongue. Material and methods. For cytogenetic examination, smears from 19 cases of squamous tongue cancer were used, after which a biopsy of the corresponding tumor sites was performed. The cytogenetic study was performed by interphase fluorescent in situ hybridization (FISH). The immunohistochemical study was performed using antibodies to Cyclin D1 and EGFR. Results. Amplification of the EGFR and CCND1 genes was detected in the tumor cells of all samples. The number of cells with amplification of the studied genes occupied a wide range. Thus, for the EGFR gene, it ranged from 1 to 59 cells, and for the CCND1 gene, it ranged from 1 to 87 cells. In 100 % of observations, EGFR and CCND1 amplification were combined. Diffuse, mostly moderate EGFR expression was detected in 17 (89 %) of the 19 observations, and focal weak expression was detected in two observations (11 %). Cyclin D1 expression in all analyzed observations was focal, weak and moderate. Conclusion. The cytogenetic features of the tongue squamous cell carcinoma are wide range of cells with amplification of EGFR and CCND1 genes, amounting to 1–59 and 1–87 cells, respectively. Tumors with EGFR amplification correspond to diffuse EGFR protein expression in 89% of cases and focal expression in 11% of cases. Tumors with CCND1 amplification correspond to the focal expression of Cyclin D1 in all observations.