%0 Journal Article %T Expression of the G protein-coupled estrogen receptor (GPER) in endometriosis: a tissue microarray study %A Nicolas Samartzis %A Eleftherios P Samartzis %A Aurelia Noske %A Andre Fedier %A Konstantin J Dedes %A Rosmarie Caduff %A Daniel Fink %A Patrick Imesch %J Reproductive Biology and Endocrinology %D 2012 %I BioMed Central %R 10.1186/1477-7827-10-30 %X A tissue microarray, which included 74 samples from different types of endometriosis (27 ovarian, 19 peritoneal and 28 deep-infiltrating) and 30 samples from normal endometrial tissue, was used to compare the expression levels of the GPER, estrogen receptor (ER)-alpha, ER-beta and progesterone receptor (PR). The immunoreactive score (IRS) was calculated separately for epithelium and stroma as the product of the staining intensity and the percentage of positive cells. The expression levels of the hormonal receptors were dichotomized into low (IRSˋ<ˋ6) and high (IRSˋ>ˋ=6) expression groups.The mean epithelial IRS (+/ˋstandard deviation, range) of cytoplasmic GPER expression was 1.2 (+/ˋ1.7, 0每4) in normal endometrium and 5.1 (+/ˋ3.5, 0每12) in endometriosis (pˋ<ˋ0.001), of nuclear GPER 6.4 (+/ˋ2.6, 0每12) and 6.8 (+/ˋ2.9, 2每12; pˋ=ˋ0.71), of ER-alpha 10.6 (+/ˋ2.4, 3每12) and 9.8 (+/ˋ3.0, 2每12; pˋ=ˋ0.26), of ER-beta 2.4 (+/ˋ2.2; 0每8) and 5.6 (+/ˋ2.6; 0每10; pˋ<ˋ0.001), and of PR 11.5 (+/ˋ1.7; 3每12) and 8.1 (+/ˋ4.5; 0每12; pˋ<ˋ0.001), respectively. The mean stromal IRS of nuclear GPER expression was 7.7 (+/ˋ3.0; 2每12) in endometrium and 10.8 (+/ˋ1.7; 6每12) in endometriosis (pˋ<ˋ0.001), of ER-alpha 8.7 (+/ˋ3.1; 2每12) and 10.6 (+/ˋ2.4; 2每12; pˋ=ˋ0.001), of ER-beta 1.8 (+/ˋ2.0; 0每8) and 5.4 (+/ˋ2.5; 0每10; pˋ<ˋ0.001), and of PR 11.7 (+/ˋ0.9; 8每12) and 10.9 (+/ˋ2.0; 3每12; pˋ=ˋ0.044), respectively. Cytoplasmic GPER expression was not detectable in the stroma of endometrium and endometriosis. The observed frequency of high epithelial cytoplasmic GPER expression levels was 50% (nˋ=ˋ30/60) in the endometriosis and none (0/30) in the normal endometrium samples (pˋ<ˋ0.001). High epithelial cytoplasmic GPER expression levels were more frequent in endometriomas (14/20, 70%; pˋ=ˋ0.01), as compared to peritoneal (9/18, 50%) or deep-infiltrating endometriotic lesions (7/22, 31.8%). The frequency of high stromal nuclear GPER expression levels was 100% (nˋ=ˋ74/74) in endometriosis and 76.7% ( %K GPER %K GPR30 %K Endometriosis %K Immunohistochemistry %K Tissue microarray %U http://www.rbej.com/content/10/1/30/abstract