ZEB1 expression is a potential indicator of invasive endometriosis

Introduction Although endometriosisis a benign disease, it shares some features with cancers, such as invasiveness and the potential to metastasize. This study sought to investigate the epithelial-mesenchymal transitionstatus in human endometriotic lesions. Material and methods Thirteen endometriosispatients and 10 control women without endometriosisundergoing surgery for benign indications were recruited. We examined the expression of E-cadherin, vimentin, and epithelial-mesenchymal transition-induced transcriptional factors, such as Snail and ZEB1, by immunohistochemistry. We evaluated the expression of each marker in epithelial cells of both endometriotic lesions (ovarian endometrioma, deep infiltrating endometriosis, adenomyosis) and normal endometria. The correlation between ZEB1 expression and serum level of CA125 was also investigated. Results Immunohistochemical analysis revealed that although E-cadherin, vimentin, and Snail were expressed in epithelia of normal endometria and endometriotic lesions, ZEB1 expression was only expressed in epithelia of endometriotic lesions. Additionally, ZEB1 was most frequently observed in epithelial cells of invasive endometriosis. The endometriosispatients with high serum CA125 level were more likely to have ZEB1-positive lesions. Conclusion This is the first observation of ZEB1 expression in epithelial cells of benign disease. The preferential expression of ZEB1 in epithelial cells of endometriotic lesions suggests that these cells may have, at least in part, a higher level of mesenchymalfeatures possibly via ZEB1-driven epithelial-mesenchymal transitionthan normal endometria and that ZEB1 can be a potential indicator of invasiveness or severity of endometriosis.