Steroid Receptor RNA Activator1(SRA1)Regulates Estrogen Receptors Expression And Affects The Biological Behaviors Of Ovarian Endometriosis

Part OneSteroid Receptor RNA Activator1(SRA1) Regulates Estrogen Receptors Expression and Affects the Proliferation of Stromal Cells Derived from Ovarian EndometriosisBackground:Estradiol and its nuclear receptors, estrogen receptor (ER)-a, and ER-β,play key roles in endometriosis and the transcriptional activity of these receptors is modulated by co-activators and co-repressors. The steroid receptor RNA activator gene (SRA1), via alternative splicing event, produces SRA long non-coding RNA (lncRNA) and SRA protein (SRAP) which regulate ERs expression at the RNA and protein levels in some hormone-dependent tumors. Objective:The aim of the study was to determine whether SRA1regulates ERs gene expression and its role in the development of ovarian endometriosis.Methods:SRAl, ERs, and progesterone receptor (PGR) expressions in human endometrial and endometriotic tissues (or stromal cells) were analyzed using Real-time RT-PCR, Western blot, and immunohistochemical techniques. The effects of SRAl on ERs expression were observed in the endometrial or endometriotic stromal cells treated with versus without SRAl small interfering RNA. The effects of SRA-siRNA on proliferation and apoptosis of endometriotic stromal cells were examined by colorimetric and flow cytometry assays, respectively.Results:High expression levels of SRAP and ER-(3but relatively low expression levels of ER-a and PGR were detected in ovarian endometriotic tissues versus normal endometrial tissues. SRA lncRNA: mRNA ratio decreased from normal endometria to ovarian endometriosis. SRAl siRNA treatment significantly increased ER-a mRNA and protein levels in endometrial or endometriotic stromal cells. However, the treatment only reduced ER-β levels in the presence of E2in endometriotic other than endometrial stromal cells. Furthermore, SRAl knockdown can attenuate the proliferation and promote early apoptosis in endometriotic stromal cells. Conclusions:SRA1gene, via decline of SRA lncRNA:mRNA ratio, plays a critical role in the development of ovarian endometriosis. SRA1regulates ERs expression and affects the proliferation in endometriotic stromal cells. Part TwoInfluence of Ovarian Endometrioma on Expression of SRA, ERs, VEGF, and TSP-1in Surrounding Ovarian TissuesThis study investigates the influence of ovarian endometrioma on expression of steroid receptor RNA activator (SRA), estrogen receptors (ERs), vascular endothelial growth factor (VEGF), and thrombospondin-1(TSP-1) in the surrounding ovarian tissues. Taken from the women with ovarian endometrioma and mature teratoma during laparoscopy, the biopsies were analyzed by real-time polymerase chain reaction (PCR) and Western blot. Our Results indicated ovarian tissues surrounding endometrioma had lower SRA and ER-a levels but higher SRAP and ER-β levels than ovarian endometrioma. With lower VEGF levels and higher TSP-1levels, surrounding ovarian tissues showed higher expression levels of SRA, SRAP, ER-a, and ER-β in ovarian endometrioma group when compared to the controls. These data showed that ovarian endometrioma increases SRA, ERs and TSP-1but decreases VEGF levels in surrounding ovarian tissues, suggesting that abnormal expression of these molecules may affect biological behaviors of ovarian endometrioma. Part ThreeIncreased SRAP Companying with Decreased ER-β Levels during the Malignant Transformation of Endometriosis Associated Ovarian Clear Cell CarcinomaObjective:To investigate the expression of steroid receptor RNA activator protein (SRAP) and estrogen receptors (ERs) in the pathogenesis from ovarian endometriosis to clear cell carcinoma.Design:Molecular studies in human tissue.Setting:University hospital research laboratory. Patient(s):Ten patients with endometriosis associated ovarian clear cell carcinoma (EAOCCC).Inter vention(s):Paraffin-embedded tissue samples were collected.Main Outcome Measure(s):SRAP, ER-a, and ER-β expressions from malignant transformation tissues of endometriosis-atypical endometriosis-ovarian clear cell carcinoma were analyzed by immunohistochemistry.Result(s):There was no change regarding ER-a level in the malignant transformation from endometriosis to atypical endometriosis to EAOCCC. During the process, a gradual increase in SRAP and a gradual reduction in ER-β expression were observed. Furthermore, there is a negative relationship between the expressions of these two molecules.Conclusion(s):An increase in SRAP and a reduction in ER-β expressions were observed with progression from endometriosis to atypical endometriosis to EAOCCC samples, which might be associated with malignant transformation to EAOCCC.