Increase of nuclear expression of metallothionein I/II in neoplastic transformation of the endometrium

Abstract

Objectives: The aim of our study was to investigate the expression of epidermal growth factor receptor (EGFR), metallothionein (MT) I/II, and Ki-67 antigen in endometrial cancer. We analyzed cytoplasmic (cMT) and nuclear (nMT) metallothionein fractions separately. Moreover, we evaluated the relationships between expressions of the above mentioned proteins and compared them with clinicopathologic data. Material and methods: The study material included paraffin-embedded endometrial cancer samples from 84 patients. The control group consisted of 52 non-neoplastic endometrium samples. Immunohistochemical reactions were performed using monoclonal antibodies against EGFR, MT I/II and Ki-67. Expression intensity of the tested proteins was assessed by computer image analysis software. Chi-square, Spearman’s correlation, Mann-Whitney and Kruskal-Wallis tests were used for statistical analysis with Statistica 8.0 PL. Results: Strong expression of nMT was revealed in endometrial cancer cells in relation to benign hyperplasia (p<0.001) and normal cells (p<0.001) of the endometrium. Statistically significant but weaker expressions in analogous relationships were observed for cMT. Moreover, higher grade of histological malignancy G was positively associated with increased expression of nMT (p=0.009). Conclusions: Expression of nMT remains in distinct correlation with neoplastic transformation of the endometrium and histologic grades. Our results clearly indicate a need for further research on metallothionein expression in tumor cells.