%0 Journal Article %T Investigation of Tenascin Expression in Endometriosis %A Zehra Sema Ozkan %A Hasan Cilgin %A Remzi Atilgan %A Mehmet Simsek %A Bengu Cobanoglu %A Necip Ilhan %A Ekrem Sapmaz %J ISRN Pathology %D 2012 %R 10.5402/2012/873759 %X Objective. To evaluate the serum and tissue levels and local expression pattern of tenascin, a high molecular weight extracellular matrix protein, in eutopic and ectopic endometrium from patients with and without endometriosis and to compare the proliferative and secretory phase differences. Materials and Methods. Thirty women with endometriosis and fifteen women without endometriosis undergoing surgery for benign indications were included in the study. Serum and tissue levels and proliferative and secretory phase expression patterns of tenascin in the ectopic and eutopic endometrium were analyzed with immunohistochemistry and immunoassays. The results were compared with Mann-Whitney U test. values <0.05 were considered as statistically significant. Results. Tenascin expression was detected in both of eutopic and ectopic endometrium of women with and without endometriosis. In immunohistochemical staining, intense staining of tenascin was observed in glandular cells of eutopic and ectopic endometrial tissue samples of both groups during secretory phase ( ). Eutopic and ectopic tissue levels of tenascin were higher than serum tenascin levels only secretory phase ( ). There was no significant difference between groups for tissue and serum levels of tenascin during cycle phases. Conclusion. Tenascin expression showed cyclic change on eutopic and ectopic endometrium. 1. Introduction Endometriosis is characterized by the presence of endometrial stromal and glandular cells outside the uterine cavity, mainly in the pelvis [1]. The exact etiology and pathophysiology of the disease is still not clear. The widely accepted theory is retrograde menstruation and implantation of endometrial cells on peritoneal surface [2¨C4]. Endometriotic cells are capable of attaching to the peritoneal mesothelium, break the peritoneal lining, and destroy extracellular matrix (ECM), thereby invading surrounding tissue [5]. ECM is involved in the regulation of these cellular events, and ECM invasion may be on the critical corner of endometriotic development. Tenascin is a high molecular weight ECM protein and plays a critical role in tissue regeneration, hyperplastic, and neoplastic processes [6]. Tenascin may have function in angiogenesis by the effect of migration of vascular endothelial cells [7]. Tenascin expression in endometrium is changing under the influence of ovarian steroids during menstruel cycle. The function of endometrial tenascin is not well known but, it is thought that tenascin plays role in endometrial regeneration and endometriotic implantation via cellular %U http://www.hindawi.com/journals/isrn.pathology/2012/873759/