{"paper_id":"170ee860-78b7-4c50-8e06-142e766fa095","body_text":"Abstract\nEndometriosis is a common gynaecological disorder of unknown aetiology. Among the several factors, estrogen has been implicated as a causative factor in endometriosis. In the present study using mouse model, we assessed the role of estrogen in the initial implantation and growth of endometrium in ectopic locations. Uterine tissues from green fluorescent protein (GFP) mice were transplanted in to the peritoneum of wild type mice in presence and absence of estrogen. As compared to untreated controls, the implantation of uterine tissue at ectopic locations was higher when estrogen was administered to both host and donor animals. However, this effect was not sustained as lesions regressed within 14 days of treatment. Irrespective of the treatment, peritoneal adipose was the most preferred site of lesion establishment. The lesions did not have typical features of the endometriosis (presence of glands and stroma) even after estrogen treatment and the ectopic tissue underwent regression by apoptosis irrespective of treatment. Since estrogen promotes implantation of endometrial tissue to ectopic locations but failure of these ectopic lesions to grow and sustain even in high estrogenic environment we propose that estrogen is necessary but not sufficient to sustain endometriosis.\nSimilar content being viewed by others\nReferences\nAbid S, Gokral J, Maitra A, Meherji P, Kadam S, Pires E, Modi D 2008 Altered expression of progesterone receptors in testis of infertile men. Reprod. BioMed. Online 17 175–184\nBecker CM, Rohwer N, Funakoshi T, Cramer T, Bernhardt W, Birsner A, Folkman J and D’Amato RJ 2008 2-Methoxyestradiol inhibits hypoxia-inducible factor-1α and suppresses growth of lesions in a mouse model of endometriosis. Am. J. 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NS is financially supported by a JRF from a DBT project (BT/514/NE/TBP/2013) to DM.\nAuthor information\nAuthors and Affiliations\nCorresponding author\nAdditional information\nCorresponding editor: S Shivaji\nRights and permissions\nAbout this article\nCite this article\nGalvankar, M., Singh, N. & Modi, D. Estrogen is essential but not sufficient to induce endometriosis. J Biosci 42, 251–263 (2017). https://doi.org/10.1007/s12038-017-9687-4\nReceived:\nAccepted:\nPublished:\nIssue date:\nDOI: https://doi.org/10.1007/s12038-017-9687-4","source_license":"CC0","license_restricted":false}