Development Of Ovarian Endometriosis Research Articles

AURKA Enhances the Glycolysis and Development of Ovarian Endometriosis Through ERβ.

Ovarian endometriosis (EMs) is a benign, estrogen-dependent gynecological disorder. Estrogen receptor beta (ERβ), a nuclear receptor for estradiol, plays an important role in the development of ovarian EMs. Here, we investigated the biological significance of aurora kinase A (AURKA) in ovarian EMs and the mechanism by which it regulates ERβ. We used immunohistochemical assays to verify that AURKA and ERβ were highly expressed in ectopic endometrial tissues. Cell proliferation and colony formation assays were used to demonstrate that AURKA promoted the proliferation of EMs cells. Wound-healing assay, Transwell migration assay, and Matrigel invasion assay further showed that AURKA enhanced the ability of EMs cells to migrate and invade. In addition, AURKA was shown to stimulate glycolysis in EMs cells by measuring the concentration of glucose and lactate in the cell supernatants. Moreover, the AURKA inhibitor alisertib was found to inhibit the progression of ovarian EMs and glycolysis in a mouse model of EMs by measuring ectopic tissues as well as by testing the peritoneal fluid of mice. Furthermore, coimmunoprecipitation assay showed that AURKA interacted with ERβ. The rescue experiments confirmed that AURKA regulated the development and glycolysis of ovarian EMs in an ERβ-dependent manner. AURKA contributed to the development of ovarian EMs by upregulating of ERβ. AURKA may represent a new target for the treatment of ovarian EMs.

Hypomethylation of the ENPP3 promoter region contributes to the occurrence and development of ovarian endometriosis via the AKT/mTOR/4EBP1 signaling pathway.

Growing evidence indicates that aberrant methylation is pivotal in the development and progression of endometriosis (EMs). This study explores the relationship between abnormal methylation of the ENPP3 promoter and the pathogenesis of ovarian EMs, focusing on its regulatory effect on ENPP3 expression. We analyzed the methylation levels of ENPP3 in ectopic endometrial tissues from ovarian EMs patients and in normal endometrial tissues from women without EMs. The expression and distribution of ENPP3 were evaluated using RT-qPCR and immunohistochemistry. Transwell assays were conducted to examine the impact of ENPP3 overexpression on the migratory and invasive capabilities of endometrial stromal cells. Our results demonstrated significantly reduced methylation levels at the CpG sites of the ENPP3 promoter region in ectopic endometrial tissues compared to normal endometrial tissues. RT-qPCR findings revealed a marked increase in ENPP3 expression in ovarian EMs tissues relative to endometrial tissues from patients without EMs, and this upregulation was negatively correlated with the methylation levels of the ENPP3 promoter region. Immunohistochemical analyses confirmed elevated ENPP3 expression in the glandular epithelial cells and stroma of ovarian EMs tissues. Furthermore, in vitro experiments showed that overexpressed ENPP3 notably intensified the invasion and migration of endometrial stromal cells. Transcriptome sequencing and functional analyses indicated that the increased ENPP3 expression activated the AKT/mTOR/4EBP1 signaling pathway. In summary, the study suggests that hypomethylation in the ENPP3 promoter region may contribute to the initiation and advancement of ovarian EMs by activating the AKT/mTOR/4EBP1 pathway, supporting the theory that EMs might be an epigenetically regulated disorder.

Potential clinical implications of iron metabolism in ovarian endometriosis

ObjectiveThe purpose of this study was to investigate iron metabolism indices in ovarian endometriosis (OEMs) and to demonstrate the potential clinical implications in the initiation and development of OEMs. MethodsThree datasets in Gene Expression Omnibus (GEO) database were selected to assess the expression levels of iron metabolites in endometrial tissues from patients with EMs and the health. To evaluate the differential expression of serum iron indices , hospitalized patients with OEMs and health examinees in Jilin University Second Hospital from November 2018 to December 2019 were recruited. Serum samples were obtained from 38 patients with OEMs and 36 health examinees. To compare the iron metabolism between peripheral circulation blood and local ectopic lesion, cyst fluid samples were obtained from 15 patients with ovarian chocolate cyst at the time of surgery. Iron metabolism indices include iron, transferrin (TF), ferritin, and unsaturated iron-binding capacity (UIBC)), which were measured by automatic biochemical analyzer. ResultsThe present study indicated the increased levels of the iron storage protein, ferritin, in the endometriotic tissues of patients with EMs. The expression of iron and ferritin in cyst fluid of patients with OEMs showed higher than that in serum, the results of TF and UIBC were opposite (P < 0.05). There was no statistical difference in the content of iron metabolites between patients with OEMs and the healthy examinees(P > 0.05). ConclusionThe ovarian chocolate cyst fluid and endometriotic tissues in patients with OEMs could more directly reflect the pathological changes of local ectopic lesion, which usually manifested as high levels of free iron and/or iron deposits in the ectopic sites. The implications of our work suggest iron metabolites in the serum may have potentially limited value as circulating biomarkers for OEMs. The iron variation in local lesions may be not only regulated by liver that mainly manipulate the systematic iron homeostasis, but also be tuned by the iron regulatory protein (IRP)/ iron responsive element (IRE) system. In summary, the iron metabolites, especially the iron and ferritin in the cyst fluid and endometriotic tissues, are meaningful biomarkers involved in the process of pathophysiology and pathogenesis of OEMs.

Genetic Variation of Glutathione S-Transferase M1 Is Associated with Patients with Ovarian Endometriosis and Endometriosis-Related Primary Infertility

Background: The aim of the study was to investigate the role of the genetic variation of glutathione S-transferase M1 (GSTM1) in the development of ovarian endometriosis and endometriosis-related primary infertility risk. Methods: This case-control study included 564 women with ovarian endometriosis and 576 normal women in the control group in northern China. The polymorphism of GSTM1 was genotyped by polymerase chain reaction (PCR)/ligase detection reaction method. To assess the biological significance of polymorphisms, the level of GSTM1 mRNA expression in patients’ endometrial tissues with different genotypes was detected by quantitative real-time PCR (qRT-PCR). Results: Compared with the positive genotype, the null genotype of GSTM1 was associated with the risk of developing ovarian endometriosis (OR = 1.29, 95% CI = 1.02–1.62). Further analysis showed that patients with a null genotype also had a significantly higher risk of primary infertility than patients with positive genotypes (OR = 1.59, 95% CI = 1.01–2.49). In addition, we found that GSTM1 mRNA expression was present in the endometrial tissue of all patients, but the expression level of patients with a positive genotype was nearly 10 times higher than that of patients with a negative genotype. Conclusion: Our results suggest that the GSTM1 polymorphism is not only related to the genetic susceptibility to ovarian endometriosis but also a potential molecular marker of primary infertility in patients with ovarian endometriosis.

A novel non-invasive molecular biomarker in ovarian endometriosis: estrogen-related receptor α.

This study aimed to explore whether estrogen-related receptors α (ERRα) can prognosticate the occurrence and development of ovarian endometriosis (EMs) as a non-invasive biomarker. The ectopic and its' correspond eutopic endometria from 47 patients with ovarian EMs and the control normal endometria from 32 cases were collected and detected the mRNA expression of ERRα by RT-qPCR. The serum protein of ERRα were tested by ELISA. The menstrual cycle, ovarian cyst sizes, relative clinical tumour markers, such as CA125, CA19-9 and HE-4, and other demographic data were also involved into analysis in these patients by SPSS 22.0 (IBM, Chicago, IL, USA). The ERRα mRNA expression in ectopic endometria were significantly lower than it in eutopic endometria (P < 0.05) and the normal endometria (P < 0.05). Similarly, the serum ERRα levels in patients with EMs were significantly lower than it in control group (P < 0.01). Moreover, the serum ERRα levels were decreasing with the increasing of the pathological stages and ovarian cyst sizes. While, the serum CA125, CA19-9, CA125/ERRα ratio and CA19-9/ERRα ratio in the study group were significantly higher than those in the control group (all P < 0.01). The expression of ERRα is correlated with the development of ovarian EMs pathological stages and ovarian cyst sizes and can be used as a novel and non-invasive biomarker for evaluating the progression of ovarian EMs.

E2 -mediated EMT by activation of β-catenin/Snail signalling during the development of ovarian endometriosis.

Endometriosis is an oestrogen‐dependent disease, and epithelial‐mesenchymal transition (EMT) is involved in the process of endometriosis. Whether oestrogen could induce EMT in endometriosis remains largely unknown. Here, we reported that up‐regulated expression of EMT markers in ovarian chocolate cyst is accompanied by high expression 17β‐hydroxysteroid dehydrogenase 1 (17β‐HSD1), and exposure of primary human endometrial epithelial cells to oestradiol conditions could promote EMT occurrence and activate both β‐catenin and Snail signalling. Furthermore, we found nuclear β‐catenin and Snail expression was closely linked in ovarian endometriosis, and β‐catenin knockdown abrogated oestrogen‐induced Snail mediated EMT in vitro. This is due to that β‐catenin/ TCF‐3 could bind to Snail promoter and activate its transcription. These results suggested that β‐catenin signalling functions as the Snail activator and plays a critical role in oestradiol‐induced EMT in endometriosis.

Aberrant expression of CHL1 gene and long non-coding RNA CHL1-AS1, CHL1-AS2 in ovarian endometriosis

Objective(s)CHL1 (close homologue of L1 or cell adhesion molecule L1 like), also referred as CALL, is a member of the L1 gene family of neural cell adhesion molecules and belongs to immunoglobulin superfamily. This study aims to investigate the potential correlation of the CHL1 gene and the long non-coding RNAs (lncRNAs), i.e., CHL1-AS1 and CHL1-AS2, and to validate the expression patterns of CHL1 and CHL1-AS2 in ovarian endometriosis (EM). Study designOur previous microarray analyses (GSE86534) of 4 patients with ovarian EM indicated that CHL1 was the most upregulated mRNA in ectopic endometrium (EC) compared with eutopic endometrium (EU) tissues, and that its two antisense lncRNAs CHL1-AS1 and CHL1-AS2, exhibited the same expression pattern. We used a bioinformatics-based strategy to calculate the correlation among CHL1, CHL1-AS1 and CHL1-AS2. Gene set enrichment analysis (GSEA) was performed to analyze commonly enriched gene sets for CHL1-AS1 and CHL1-AS2. Using quantitative real-time polymerase chain reaction (qPCR), we examined the expression levels of CHL1 mRNA and lncRNA CHL1-AS2 in paired tissues of EC and EU from 30 EM patients and normal endometrium (NE) tissues from 27 controls using quantitative real-time polymerase chain reaction (qPCR). We also examined the expression of CHL1 protein in EC, EU and NE tissues using western blotting and immunohistochemistry (IHC). ResultsCHL1, CHL1-AS1 and CHL1-AS2 were significantly correlated with each other given that the Pearson correlation values were > 0.9 using bioinformatic calculation. GSEA revealed that CHL1-AS1 and CHL1-AS2 were negatively associated with the same gene set “WAMUNYOKOLI_OVARIAN_CANCER_LMP”. qPCR confirmed that the CHL1 and CHL1-AS2 expression levels were significantly higher in EC tissues than in EU and NE tissues, while they were not significantly different in EU compared with NE tissues. The relative expression levels of CHL1 and CHL1-AS2 in EC compared with EU tissues were positively significantly correlated (Pearson correlation coefficient = 0.421 and P value = 0.02). Elevated expression of CHL1 protein in EC tissues was detected by western blotting. IHC revealed that CHL1 protein expression levels enhanced in ectopic endometrial glands and stroma. Conclusion(s)Our results indicate a significant correlation among CHL1, CHL1-AS1 and CHL1-AS2, which might be involved in the development of ovarian EM and serve as novel targets for future research.

Aberrant methylation of the IL-12B promotor region contributes to the risk of developing ovarian endometriosis.

Studies have shown that aberrant expression of IL-12p40, which is encoded by the interleukin-12B (IL-12B) gene, may be involved in the development of endometriosis. In this study, we investigated the role of aberrant methylation of the IL-12B promoter region and its associated expression in the development of ovarian endometriosis. By using pyrosequencing, we analyzed the methylation level of the IL-12B promoter region in eutopic and ectopic endometrium of patients with ovarian endometriosis and normal endometrium of control women. The expression of IL-12B mRNA was detected by quantitative real-time PCR. The results showed that the methylation level of the IL-12B promoter region in ectopic and eutopic endometrium of patients with ovarian endometriosis was significantly lower than that in endometrium of women without endometriosis ( p < 0.001 and p = 0.041, respectively). In contrast, mRNA levels were significantly increased in ectopic and eutopic endometrium of patients with ovarian endometriosis compared to those in endometrium of women without endometriosis ( p < 0.001 and p = 0.042, respectively). Correlation analysis showed that the methylation level of the IL-12B promoter region was negatively correlated with mRNA levels of IL-12B ( p < 0.001). Our data suggested that aberrant methylation of the IL-12B promoter region may be responsible for aberrant IL-12B mRNA expression in endometrium tissue of women, which may be associated with the development of ovarian endometriosis in northern Chinese women.

Novel CTCF mutations in Chinese patients with ovarian endometriosis.

Endometriosis is a common gynecological disease characterized by the outgrowth of the endometrium, however, the detailed molecular etiology remains largely uncharacterized. Recent studies have implicated that endometriosis is potentially a precancerous lesion, and that CCCTC‑binding factor (CTCF) mutations may be involved in the pathogenesis of this disorder. However, the detailed CTCF mutation spectrum in Chinese patients with ovarian endometriosis remains largely unknown. In the present study, a cohort of 92patients with ovarian endometriosis were analyzed for the presence of CTCF mutations by sequencing the entire coding regions. In addition, 67 healthy eutopic endometrial tissues and 46healthy ovarian tissues from control samples (without endometriosis) were also analyzed. In total, two CTCF missense mutations, p.K206E (c.616A>G) and p.H373L (c.1118A>T), were identified in 2/92 (2.2%) endometriotic lesions. The patient with the p.K206E mutation was 26years old and diagnosed with primary infertility, whereas the patient with the p.H373L mutation was 37years old and concurrently diagnosed with uterine leiomyoma. The p.H373L mutation was previously identified in endometrial cancer samples with low frequency, while the p.K206E mutation was novel. In addition, no CTCF mutations were detected in the 67healthy eutopic endometrial and 46 healthy ovarian tissue samples. Insilico prediction and evolutionary conservation analysis suggested that these CTCF mutations may be pathogenic. In summary, the present study identified 2potential pathogenic CTCF mutations in endometriotic lesions from 2/92patients with ovarian endometriosis. These results, together with a prior exome‑sequencing based study, suggest that CTCF mutations may be involved in the development of ovarian endometriosis.

Analysis of CARD10 and CARD11 somatic mutations in patients with ovarian endometriosis.

Endometriosis is a complex and heterogeneous pre-malignant inflammatory disease harboring multiple gene mutations. Previous studies have suggested that caspase recruitment domain family member (CARD)10 and CARD11 mutations may exist in endometriosis. In the present study, a collection of endometriotic lesions and paired peripheral blood from 101 patients with ovarian endometriosis were obtained, and the entire coding sequences of the CARD10 and CARD11 genes were sequenced. Evolutionary conservation analysis and online prediction programs were applied to analyze the disease-causing potential of the identified mutations. A total of 4 novel somatic mutations were identified in 4 out of the 101 (4.0%) samples: 2 in-frame deletions in CARD10 (c.785_790delAGGAGA, p.K272_E273delKE; c.785_802delAGGAGAAGGAGAAGGAGA, p.K272_V277delKEPDNV) and 2 heterozygous missense mutations in CARD11 (c.49G>T, p.D17Y; c.160G>C, p.E54Q). The sample with CARD10 p.K272_E273delKE deletion was obtained from a 47-year-old patient who was also diagnosed with uterine leiomyoma, while the CARD10 p.K272_V277delKEPDNV-mutated sample was from a 43-year-old patient exhibiting a decreased blood eosinophil granulocyte ratio (0.3%) and an elevated serum creatine kinase level (314 U/l). The patient with the CARD11 p.D17Y mutation was 38 years old and exhibited an increased level of cancer antigen 125 (45.4 U/ml), while the patient with the CARD11 p.E54Q mutation was 46 years old and exhibited no other gynecological conditions. Evolutionary conservation analysis and online prediction programs suggested that these mutations may be disease-causing. In summary, 4 novel somatic mutations in the CARD10 and CARD11 genes were identified from amongst 101 cases of ovarian endometriosis for the first time, these mutations may serve active roles in the development of ovarian endometriosis.

Epithelial-to-mesenchymal transition and stem cells in endometrial cancer

This review article describes the main features of epithelial-to-mesenchymal transition (EMT) and its possible role in understanding myometrial invasion in endometrial carcinoma (EC), as well as the development of malignant mixed Müllerian tumor (MMMT). Moreover, the article discusses the possible role of somatic (SSC) and cancer stem cells (CSC) in EC. Different transcriptional repressors of E-cadherin have been identified in EMT, including Snail and Slug, ZEB1 and ZEB2, and E47 and Twist. The expression of some of these genes is increased at the myoinvasive front and correlates inversely with E-cadherin inmunoreactivity. Whereas the transient occurrence of the EMT phenomenon is important for myometrial invasion in conventional EC, MMMT shows permanent expression of EMT leading to repression of E-cadherin and increased expression of mesenchymal markers including proteins involved in skeletal muscle development. An SSC population, identified as a side population, assessed by the Hoechst dye exclusion test has been identified in human endometrium. CSCs have been defined in analogy to SSC as cancer cells that have the capacity to self-renew, which means undergoing divisions that allow the generation of more identical CSCs and give rise to the variety of more differentiated cells found in the malignancy. Although published data show that CD133(+) cells retain the characteristics of CSC, there is no conclusive evidence showing that CD133 is the universal marker for EC stem cells. Finally, a possible role for endometrial stem cells in the development of ovarian endometriosis and ovarian endometrioid carcinoma is commented.

Unravelling the Ovarian Endometrioma Pathogenesis: “The Long and Winding Road” across the Various Theories

Controversy exists regarding the pathogenesis of endometriotic ovarian cysts. Different and complex theories have been proposed over the years since the description of chocolate cysts by Sampson in 1921. We have herein reviewed findings in support and against the most widely accepted theories. According to the theory of Hughesdson and Brosens, a prerequisite for endometrioma formation seems to be the inversion and progressive invagination of the ovarian cortex after the accumulation of menstrual debris derived from bleeding of superficial endometriotic implants, which are located on the ovarian surface and adherent to the peritoneum. Disproving the metaplasia hypothesis put forward by Donnez and coworkers and supporting the involvement of the ovulation process in the development of ovarian endometriosis, Vercellini and colleagues have recently demonstrated that a cystic corpus luteum may be a transitory step toward endometrioma formation. As these theories are not able to explain the various aspects of endometrioma formation fully, the possibility that the coelomic metaplasia of the ovarian mesothelium with changes into typical endometrial glands and stroma might be responsible for the endometrioma formation cannot be totally ruled out. Further research is needed to clearly elucidate the pathogenetic aspects of endometriotic ovarian cysts.

Study on expression of estrogen receptor isoforms in eutopic and ectopic endometrium of ovarian endometriosis

To investigate the distribution of ER isoforms in endometriosis and eutopic endometrium. Tissue samples of patients with ovarian endometriosis, treated in People's Liberation Army General Hospital from January 2004 to December 2006, were retrieved. A total of 60 cases of ovarian endometriotic cysts with their corresponding eutopic endometrium (30 cases of proliferation phase and 30 of secretary phase eutopic endometrium) and 30 cases of normal endometrium (15 proliferative and 15 secretary phase endometrial samples respectively) were included. Expressions of ERalpha and ERbeta were analyzed using immunohistochemistry and the expression ratio was statistically analyzed by using SPSS 12.0 software. Expressions of both ERalpha and ERbeta in epithelial cells were positively correlated with that of the stromal cells. The expression of ERalpha in eutopic endometrium (73.3% in epithelium and 76.7% in stroma) was significantly higher than that in ovarian endometriotic cysts (43.3% in epithelium and 46.7% in stroma), or normal control (56.7% in epithelium and 50.0% in stroma, respectively, each P < 0.05. However, the expression of ERbeta (90.0% in epithelium and 76.7% in stroma) was higher in ovarian endometriotic cysts than that in the eutopic endometrium (68.0% in epithelium and 63.3% in stroma respectively, P < 0.05), and ERbeta expression in eutopic endometrium was higher than that in the normal control endometrium (36.7% in epithelium and 26.7% in stroma, respectively, P < 0.05). The expressions of both ERalpha and ERbeta changed periodically in eutopic and normal endometrium, whereas ERalpha and ERbeta level were less variable in the ectopic endometrium. The expression of ERbeta was statistically higher than that of ERalpha (P < 0.05) in ectopic endometrium, whereas no significant difference was seen between the two isoforms in the eutopic or normal endometrium. Both ERalpha and ERbeta have higher expression levels in eutopic endometrium of patients with ovarian endometriotic cysts. ERbeta is predominantly expressed in endometriotic cysts, where the expression of ERalpha is limited. The different distribution of ERalpha and ERbeta may play an important role in the development of ovarian endometriosis.

Arguments for a left lateral predisposition of endometrioma

To analyze a hypothesis regarding the pathogenesis of endometriosis. Retrospective study. Two academic endometriosis referral centers. We evaluated operative and pathologic reports of 251 women who underwent laparoscopic or laparotomy treatment of endometrioma from August 1996 to February of 2002 at Yale University School of Medicine and at the University of Crete Department of Obstetrics and Gynecology. Laparascopic examination. Statistical methods included chi(2) and Mann-Whitney U tests measuring incidence of right- vs. left-sided endometria. One hundred seventy patients from Yale University and 81 Greek patients participated in this study. Endometrioma was significantly more frequent in the left ovary (139 of 206 [67.4%]) than in the right ovary (67 of 206 [32.6%]; odds ratio [OR] = 4.3; 95% confidence interval [CI) 2.9-6.5; chi(2) = 48.9) and significantly different from the expected proportion of 50% (chi(2) = 25.2). When bilateral endometriomas were included, 62.1% (184 of 296) were left-sided and 37.15 (112 of 296) were right-sided (OR = 17.5; 95% CI 1.9-3.8; chi(2) = 34.1). Dilated ovarian veins in were found in 22 (68.7%) of 32 Greek cases with endometrioma. All 20 women with left endometrioma had left ovarian vein dilated. We suggest a new mechanical theory of implication, the female varicocele theory, which could play an important role in the development of ovarian endometriosis or endometriomas.