Expression of Cytokeratin 8 (CK8) in Human Endometrium and Endometriosis

Cytokeratins are a multigene family of polypeptides expressed in distinct combinations along the various routes of epithelial differentiation. In endometrial cancer and cervical intraepithelial neoplasia/cervical squamous cell carcinoma, the expression of cytokeratins correlates with aggressive tumor features, lesion grade, and the International Federation of Gynecology and Obstetrics (FIGO) stage. Although the central elements involved in the pathogenesis of endometriosis are as yet unexplained, it is generally accepted that invasive mechanisms and hormonal effects influence endometriotic disease. On the basis of a preliminary microarray analysis showing increased mRNA expression of cytokeratin 8 in peritoneal endometriosis in comparison with eutopic endometrium, the present study therefore investigated the expression of CK8 in human eutopic and ectopic endometrium, using immunohistochemical staining. The results of our analyses points to a posttranscriptional regulation of cytokeratin 8 in endometriotic lesions possibly through noncoding miRNAs.