* To whom correspondences should be addressed: r.aflatoonian@gmail.com Expression of Tumor Necrosis Factor (TNF-α) and Estrogen Receptors gene in endometrial tissue Sima Golkar1, Salehe Fallahi1, Samaneh Aghajanpour1, Fariba Ramazanali1, Ashraf Moini1, Reza Aflatoonian*1 1.Department of Endocrinology and Female infertility, Reproductive Biomedicine, Center, Royan institute for Reproductive Biomedicine, Tehran, Iran. * To whom correspondences should be addressed: r.aflatoonian@gmail.com Objectives Methods Endometriosis is classically defined as the presence of functional endometrial glands and stroma outside the uterine cavity. Physiological changes during menstrual cycle cause the endometerium and endometriosis to develop specific kind of tissues, especially in regard to the gene expression profiles. Alterations in estrogen-mediated cellular signaling play an essential role in the pathogenesis of endometriosis. ER-β interacts with cellular apoptotic machinery in the cytoplasm to inhibit TNFα induced apoptosis. Tumor necrosis factor (TNF)-alpha is a major cytokine involved in inflammatory and immune function. Our aim in this study was to determine the expression of TNFα and ERα, ERβ in endometriosis. With the usage of RT-PCR, we researched the expression of as TNFα and ERα ,ERβ reliable reference genes in Eutopic and ectopic endometrial tissue specimens obtained during standard surgery of women of reproductive age. Conclusions In RT-PCR based analyses of gene expression level in Eutopic and Ectopic endometrium, The imbalance in expression of TNFα and ERα, ERβ in the endometrium may play a role in the development of endometriosis. Result References 1.Han SJ, Jung SY, Wu SP, Hawkins SM, Park MJ, Kyo S, Qin J, Lydon JP, Tsai SY, Tsai MJ, DeMayo FJ. Estrogen receptor β modulates apoptosis complexes and the inflammasome to drive the pathogenesis of endometriosis. Cell. 2015 Nov 5;163(4):960-74. 2. Díaz-Gimeno P, Horcajadas JA, Martínez-Conejero JA, Esteban FJ, Alamá P, Pellicer A, Simón C. A genomic diagnostic tool for human endometrial receptivity based on the transcriptomic signature. Fertility and sterility. 2011 Jan 1;95(1):50-60. s During this study, changes in the expression of TNFα and ERα ,ERβ were observed between endometriosis groups. Eutopic endometrium of women with endometriosis had higher expression levels of ER-α, ER-β mRNA and lower expression levels of TNF-α mRNA than that of women with Ectopit endometriosis.