Differences in Invasive Capacity of Endometrial Cancer Cell Lines Expressing Different Progesterone Receptor Isotypes: Possible Involvement of Cadherins

Objective: Loss of expression of progesterone receptors (PR) in endometrial cancer is related to a more invasive and metastatic phenotype. In this study we aim to investigate whether selective loss of PRA or PRB affects the invasive capacity of endometrial cancer cells.Methods: cDNA microarrays were performed to compare gene expression profiles of a set of endometrial cancer sub-cell lines expressing PRA and/or PRB. In vitro invasion assays were performed to assess whether differences in gene expression between the lines were reflected by their invasive behavior.Results: It was observed that cell lines that express only PRA express higher levels of cadherins, and show a lower level of invasion compared to cell lines that express PRB. When cadherin function was inhibited in exclusively PRA-expressing cell lines, an increase of in vitro invasion was observed. In support of thesefindings, it was observed that in higher grade and more invasive endometrial cancer, expression of E-cadherin decreased.Conclusions...