Investigating of the EZH2 protein in normal endometrium, endometrial hyperplasia and endometrium cancers with the molecular methods

Objective: The aim of this study, in terms of malignity, is to investigate the Enhancer of Zeste Homolog-2 (EZH2)'s role in two different human endometrium cancer cell lines and in the normal endometrium, endometrial hyperplasia and endometrium cancers. Material and methods: On the human endometrium cancer cell lines Ishikawa and MFE-319 (ACC-423); normal endometrium (proliferation and secretion stage); endometrial hyperplasia (basic non-atypia and complex atypia) and endometrial adenocarcinoma (Type I and Type II) samples, the evaluation of EZH2 protein was made with the indirect immunohistochemical and Western blotting methods. With the TUNEL method, the percentage of apoptotic indexes was evaluated. The immunoreactivity staining of the EZH2 protein was detected as light (1), medium (2), strong (3) and very strong (4). Stained cell numbers were counted as percent rate, with the staining intensity, the H-score was obtained, and then the results were evaluated by using the One-way ANOVA statistical test in a comparative manner. P<0.05 was accepted as significant. Results: In this study, the two different human endometrial cell lines were evaluated comparatively with the EZH2 immunoreactivity in terms of malignity. The aggressive MFE319 human endometrium cell line was strongly (4) stained, meanwhile the Ishikawa cells were stained as light/medium (1/2) degrees (p<0.05). After the histopathologic evaluation, when the EZH2 immunoreactivity was evaluated in the endometrium samples, at the transition at normal endometrium to hyperplasia and at the transition of endometrial hyperplasia to carcinogenesis process; statistically increased EZH2 immunoreactivity was observed. When the percent of TUNEL indexes were evaluated, at the later stage of cancer progression, TUNEL positive cell numbers increased in a statistically significant manner. With the Western Blotting method, EZH2 protein presence was detected at the human cell lines. Conclusion: In the two different human endometrium cancer cell lines that differ in the way of malignity and from the normal endometrium to endometrial hyperplasia to the carcinogenesis process; the significance of the EZH2 protein was revealed as a prognostic factor and as a target molecule in cancer treatment.