The Epithelial-Mesenchymal Transition, E-cadherin and Tumor Progression in Ovarian Serous Tumors.

Abstract

The epithelial-mesenchymal transition (EMT), which is a change in the cell phenotype from epithelial to mesenchymal morphology, is an important step in the invasion process and metastasis of ovarian carcinomas. It is known that the suppression of cell adhesion molecules such as E-cadherin and the expression of mesenchymal markers such as Vimentin are key processes in EMT. There is controversy in the literature about the EMT status of ovarian carcinomas. To investigate EMT status using immunohistochemical expression of E-cadherin in benign, primary malignant serous ovarian tumors and metastases from them in order to assess their significance in tumor progression. The study included a retrospective investigation of 217 ovarian epithelial tumors. Ninety-two cases of serous ovarian tumors and metastases were examined for expression of E-cadherin. In our study, the predominant histological subtype in benign ovarian tumors and carcinomas was serous (73% and 61%, respectively). 65% of benign tumors demonstrated EMT negative status. The majority of carcinomas demonstrated EMT positive status (82%), whereas negative EMT status was only observed in 18% of cases. 89% of the metastases showed EMT positive status, whereas only 11% of them showed negative EMT status. In 6 selected cases with positive EMT status we found Vimentin expression in tumor cells. Positive EMT status (reduced E-cadherin expression) is a characteristic of ovarian carcinomas and metastases, but not of benign serous ovarian tumors.