Evaluation of the expression of 5-HMC and HDAC6 genes involved in epigenetic modification in the carcinogenesis of endometrial carcinoma

Objective: The aim of this study was to evaluate the expression of 5-hmC and HDAC6 genes involved in epigenetic modification in the carcinogenesis stages of endometrial carcinoma. There are very few studies in the literature investigating the expression of 5-hmC and HDAC6 in endometrial cancer and precancerous lesions. In the light of the results obtained in this study; with future molecular studies, it is aimed that our study will contribute to the discovery of new biomarkers related to the epigenetic modification of endometrial carcinoma. Material and Methods: Cases diagnosed between 2010-2019 in Karadeniz Technical University Faculty of Medicine, Department of Medical Pathology were classified as n=20 in each group as proliferative endometrium, endometrial hyperplasia without atypia, hyperplasia with atypia, and endometrial adenocarcinoma (grade 1-2-3). According to the results of the archive scanning, the age, gravida, menopausal status, smoking, CA125 level, endometrial thickness and body mass index data of the cases were recorded from the hospital system; myometrial invasion and lymphovascular invasion status of the cases in the endometrial adenocarcinoma group were also evaluated. Hematoxylin & Eosin stained preparations of the cases were reevaluated and appropriate blocks were selected for immunohistochemical examination. Results: While expression of 5-hmC is high in benign conditions, loss of expression was observed in the endometrial carcinoma group. The difference between the groups in terms of 5-hmC expression was statistically significant (p=0.001). A statistically significant difference was observed between endometrial adenocarcinoma and hyperplasia with atypia and proliferative endometrium. HDAC6 expression was found to be significantly lower in endometrial adenocarcinoma cases compared to other groups. The difference between groups in terms of HDAC6 expression was statistically significant (p=0.000). There was a statistically significant difference in HDAC6 expression between endometrial adenocarcinoma and hyperplasia with atypia, hyperplasia without atypia and proliferative endometrium groups. No statistically significant difference was found between the well, moderately and poorly differentiated endometrial adenocarcinoma groups in terms of 5-hmC and HDAC6 expression. When compared according to the menopausal status, the HDAC6 and 5-hmC averages of those in the premenopausal period were found to be significantly higher than the average of those in the postmenopausal period. There was no significant difference between the expressions of molecules and clinical parameters such as CA125 value, body mass index, intrauterine device and oral contraceptive use. Conclusion: In our study, it was seen that 5-hmC and HDAC6 genes, which are involved in epigenetic modification, may be useful in differentiating endometrial cancer from precancerous lesions. However, in this context, studies with more detailed clinical and pathological data in higher numbered patient groups are required. Since 5-hmC averages were found to be low in high-grade endometrioid cancers, it was thought to have prognostic significance. Although HDAC6 expression was increased in various cancers in the literature review, it was observed that the expression was decreased in endometrial cancer tissue in our study. This finding is inconsistent with the literature.