Molecular mechanisms of treatment resistance in endometriosis: the role of progesterone-hox gene interactions

Generation of epithelial-stromal assembloids as an advanced in vitro model of impaired adenomyosis-related endometrial receptivity

OBJECTIVE

To create a novel, more advanced in vitro model of human endometrium, using so-called assembloids, looking to explore endometrial receptivity in adenomyosis.

DESIGN

Evaluation of assembloid responsiveness to hormonal stimulation by immunohistochemistry, enzyme-linked immunosorbent assay, and scanning electron microscopy.

SETTING

University-based research unit in gynecology.

PATIENT(S)

Twelve women, six of whom were affected by adenomyosis.

INTERVENTION(S)

Organoids (in the form of glandular fragments) and stromal fibroblasts were collected from endometrial biopsies. The two populations were combined inside an extracellular matrix to create 3D assembloids, which were then exposed to hormonal stimulation (β-estradiol for 48 hours, followed by β-estradiol/progesterone/cyclic adenosine monophosphate for 72 hours) to mimic the window of implantation.

MAIN OUTCOME MEASURE(S)

Glycodelin, leukemia inhibitory factor (LIF), and homeobox A10 (HOXA10) expression, prolactin secretion, and pinopode development.

RESULT(S)

Endometrial organoids and stromal cells were successfully isolated from women with and without adenomyosis and combined to generate the assembloid model. On stimulation, assembloids from both groups acquired a more secretory phase-like phenotype, as demonstrated by histology, and were shown to be positive for glycodelin, LIF, and HOXA10 by immunohistochemistry. Adenomyotic assembloids expressed significantly lower levels of LIF and HOXA10 within the stromal compartment after stimulation than did healthy assembloids in the same condition. Enzyme-linked immunosorbent assay revealed prolactin secretion in vitro, showing an upward trend in hormonally treated assembloids from both healthy and affected women. By scanning electron microscopy, fully formed pinopodes were discerned on the epithelial surface of healthy assembloids after stimulation, but they were absent in case of adenomyosis.

CONCLUSION(S)

Primary assembloids can be generated from endometrial biopsies from both healthy subjects and women affected by adenomyosis. These assembloids are amenable to hormonal stimulation and mimic secretory phase-specific characteristics of endometrial tissue in vivo, including glycodelin, LIF, and HOXA10 expression, and pinopode formation. Assembloids from adenomyosis appear to be less sensitive to hormonal treatment, showing reduced expression of LIF and HOXA10 in the stromal compartment and failing to form pinopodes. All in all, endometrial assembloids may serve as an advanced preclinical model of adenomyosis-related impaired endometrial receptivity, opening up new horizons in understanding and treating the condition.

The role of progesterone and estrogen receptors in treatment choice after endometriosis surgery: A cross-sectional study

Background

The lack of improvement in some endometriotic people's pain after surgery even while using hormone treatment may suggest an inappropriate response to routine hormonal therapies.

Objective

This study aimed to determine a cut-off point for selecting the most appropriate treatment based on the hormone receptors of endometriotic lesions.

Materials and Methods

In this cross-sectional study, by reviewing the medical records of participants and testing their archive samples and phone interviews (if needed), 86 symptomatic women after endometriosis surgery who were operated into governmental hospitals, Shahid Faghihi and Hazrate Zeinab Shiraz Iran were enrolled between March 2017 and March 2019. Women were divided into 2 groups: responsiveness (n = 73 for dysmenorrhea, n = 60 for dyspareunia) to medical treatment and surgery, and unresponsiveness (n = 13, n = 7). We examined the pathological slides of 86 women to determine the amount of hormone receptors and the relationship between the type of medical treatment and the level of hormone receptors on pain relief within 1 yr after surgery.

Results

Based on the receiver operating characteristic curve, dysmenorrhea in the presence of tissue estrogen receptors > 60% (p = 0.1065), and dyspareunia in the presence of tissue progesterone receptors > 80% (p = 0.0001) responded well to medical treatment after surgery. In the presence of endometrioma-dysmenorrhea showed the best response to oral contraceptive pills (69.4%), while in deep infiltrative endometriosis-dyspareunia showed the best response to progesterone treatment (75%).

Conclusion

Prescribing an appropriate hormone therapy based on a specific immunohistochemistry staining pattern can improve the life quality of postoperative endometriosis individuals.

Affinity-tagged SMAD1 and SMAD5 mouse lines reveal transcriptional reprogramming mechanisms during early pregnancy

Endometrial decidualization, a prerequisite for successful pregnancies, relies on transcriptional reprogramming driven by progesterone receptor (PR) and bone morphogenetic protein (BMP)-SMAD1/SMAD5 signaling pathways. Despite their critical roles in early pregnancy, how these pathways intersect in reprogramming the endometrium into a receptive state remains unclear. To define how SMAD1 and/or SMAD5 integrate BMP signaling in the uterus during early pregnancy, we generated two novel transgenic mouse lines with affinity tags inserted into the endogenous SMAD1 and SMAD5 loci (Smad1HA/HA and Smad5PA/PA). By profiling the genome-wide distribution of SMAD1, SMAD5, and PR in the mouse uterus, we demonstrated the unique and shared roles of SMAD1 and SMAD5 during the window of implantation. We also showed the presence of a conserved SMAD1, SMAD5, and PR genomic binding signature in the uterus during early pregnancy. To functionally characterize the translational aspects of our findings, we demonstrated that SMAD1/5 knockdown in human endometrial stromal cells suppressed expressions of canonical decidual markers (IGFBP1, PRL, FOXO1) and PR-responsive genes (RORB, KLF15). Here, our studies provide novel tools to study BMP signaling pathways and highlight the fundamental roles of SMAD1/5 in mediating both BMP signaling pathways and the transcriptional response to progesterone (P4) during early pregnancy.

Affinity-tagged SMAD1 and SMAD5 mouse lines reveal transcriptional reprogramming mechanisms during early pregnancy

Endometrial decidualization, a prerequisite for successful pregnancies, relies on transcriptional reprogramming driven by progesterone receptor (PR) and bone morphogenetic protein (BMP)-SMAD1/SMAD5 signaling pathways. Despite their critical roles in early pregnancy, how these pathways intersect in reprogramming the endometrium into a receptive state remains unclear. To define how SMAD1 and/or SMAD5 integrate BMP signaling in the uterus during early pregnancy, we generated two novel transgenic mouse lines with affinity tags inserted into the endogenous SMAD1 and SMAD5 loci (Smad1HA/HA and Smad5PA/PA). By profiling the genome-wide distribution of SMAD1, SMAD5, and PR in the mouse uterus, we demonstrated the unique and shared roles of SMAD1 and SMAD5 during the window of implantation. We also showed the presence of a conserved SMAD1, SMAD5, and PR genomic binding signature in the uterus during early pregnancy. To functionally characterize the translational aspects of our findings, we demonstrated that SMAD1/5 knockdown in human endometrial stromal cells suppressed expressions of canonical decidual markers (IGFBP1, PRL, FOXO1) and PR-responsive genes (RORB, KLF15). Here, our studies provide novel tools to study BMP signaling pathways and highlight the fundamental roles of SMAD1/5 in mediating both BMP signaling pathways and the transcriptional response to progesterone (P4) during early pregnancy.

Epigenetic Dysregulation in Endometriosis: Implications for Pathophysiology and Therapeutics

Endometriosis is a prevalent gynecological condition associated with pelvic pain and infertility. Despite more than a century of research, the etiology of endometriosis still eludes scientific consensus. This lack of clarity has resulted in suboptimal prevention, diagnosis, and treatment options. Evidence of genetic contributors to endometriosis is interesting but limited; however, significant progress has been made in recent years in identifying an epigenetic role in the pathogenesis of endometriosis through clinical studies, in vitro cell culture experiments, and in vivo animal models. The predominant findings include endometriosis-related differential expression of DNA methyltransferases and demethylases, histone deacetylases, methyltransferases, and demethylases, and regulators of chromatin architecture. There is also an emerging role for miRNAs in controlling epigenetic regulators in the endometrium and endometriosis. Changes in these epigenetic regulators result in differential chromatin organization and DNA methylation, with consequences for gene expression independent of a genetic sequence. Epigenetically altered expression of genes related to steroid hormone production and signaling, immune regulation, and endometrial cell identity and function have all been identified and appear to play into the pathophysiological mechanisms of endometriosis and resulting infertility. This review summarizes and critically discusses early seminal findings, the ever-growing recent evidence of epigenetic contributions to the pathophysiology of endometriosis, and implications for proposed epigenetically targeted therapeutics.

Aberrant epigenetic regulation of estrogen and progesterone signaling at the level of endometrial/endometriotic tissue in the pathomechanism of endometriosis

Endometriosis is a term referring to a condition whereby the endometrial tissue is found outside the uterine cavity. This progressive and debilitating condition affects up to 15% of women of reproductive age. Due to the fact that endometriosis cells may express estrogen receptors (ERα, Erβ, GPER) and progesterone (P4) receptors (PR-A, PR-B), their growth, cyclic proliferation, and breakdown are similar to the processes occurring in the endometrium. The underlying etiology and pathogenesis of endometriosis are still not fully explained. The retrograde transport of viable menstrual endometrial cells with the retained ability to attach within the pelvic cavity, proliferate, differentiate and invade into the surrounding tissue explains the most widely accepted implantation theory. Endometrial stromal cells (EnSCs) with clonogenic potential constitute the most abundant population of cells within endometrium that resemble the properties of mesenchymal stem cells (MSCs). Accordingly, formation of the endometriotic foci in endometriosis may be due to a kind of EnSCs dysfunction. Increasing evidence indicates the underestimated role of epigenetic mechanisms in the pathogenesis of endometriosis. Hormone-mediated epigenetic modifications of the genome in EnSCs or even MSCs were attributed an important role in the etiopathogenesis of endometriosis. The roles of excess estrogen exposure and P4 resistance were also found to be crucial in the development of epigenetic homeostasis failure. Therefore, the aim of this review was to consolidate the current knowledge regarding the epigenetic background of EnSCs and MSCs and the changed properties due to estrogen/P4 imbalances in the context of the etiopathogenesis of endometriosis.

Loss of HOXA10 causes endometrial hyperplasia progressing to endometrial cancer

Endometrial cancer is the fourth most common malignancy in women and the precursor lesion is endometrial hyperplasia. HOXA10 is a transcription factor that plays key roles in endometrial functions such as the endowment of receptivity, embryo implantation, and trophoblast invasion. Herein, using testicular transgenesis, we developed transgenic mice that expressed a shRNA against HOXA10 and there was a nearly 70% reduction in the expression of HOXA10 in these animals. We observed that downregulation of HOXA10 led to the development of endometrial hyperplasia in the young animals (3 months), and as they aged (>1 year), most animals developed well-differentiated endometrial adenocarcinoma. In the endometrium of animals with reduced HOXA10, there was increased proliferation and elevated levels of ERα and ERβ. In parallel, there was increased expression of Wnt4 and β-Catenin, SOX9, and YAP1. We propose that chronic reduction in HOXA10 expression disrupts multiple pathways in the uterus that aids in the development of endometrial hyperplasia which progresses to endometrial cancer with age.

Progesterone Receptor Status of Epithelial Cells as a Predictive Marker for Postoperative Recurrence of Endometriosis

CONTEXT

Progesterone resistance including progesterone receptor (PR) deficiency contributes to the pathophysiology of endometriosis; however, whether the PR expression levels in ovarian endometrioma (OE) correlate with the postoperative recurrence of endometriosis remains unclear.

OBJECTIVE

This study aimed to investigate the association between PR expression levels in OE and the recurrence of endometriosis.

METHODS

OE specimens were obtained from 132 patients who underwent conservative surgery for endometriosis. The PR expression levels were evaluated using the H score after immunohistochemical staining.

RESULTS

Of the 132 patients, 36 (27.3%) experienced recurrence and 96 (72.7%) did not. No differences were observed in the patient characteristics between the recurrence and nonrecurrence groups except for follow-up period. PR immunoreactivity in the epithelial cells (ECs) was statistically significantly lower in the recurrent group than in the nonrecurrent group (P < .01); however, this change was not observed in the stromal cells. Moreover, multivariable logistic regression analysis revealed that the H score of PR in ECs was an independent factor and was statistically significantly associated with the recurrence of endometriosis (P = .01). Furthermore, we divided the patients into PR-negative or PR-positive groups. The cumulative recurrence rate in the negative PR group was statistically significantly higher than that in the positive PR group (P = .046).

CONCLUSION

Low PR expression levels in OE-ECs may predict the recurrence of endometriosis. The PR status in OE-ECs is associated with the pathophysiology of the recurrence of endometriosis, and optimized postoperative management for endometriosis may be provided by referring to the PR status.

Epigenetic Factors in Eutopic Endometrium in Women with Endometriosis and Infertility

Eutopic endometrium in patients with endometriosis is characterized by aberrant expression of essential genes during the implantation window. It predisposes to disturbance of endometrial receptivity. The pathomechanism of implantation failures in women with endometriosis remains unclear. This paper aims to summarize the knowledge on epigenetic mechanisms in eutopic endometrium in the group of patients with both endometriosis and infertility. The impaired DNA methylation patterns of gene promoter regions in eutopic tissue was established. The global profile of histone acetylation and methylation and the analysis of selected histone modifications showed significant differences in the endometrium of women with endometriosis. Aberrant expression of the proposed candidate genes may promote an unfavorable embryonic implantation environment of the endometrium due to an immunological dysfunction, inflammatory reaction, and apoptotic response in women with endometriosis. The role of the newly discovered proteins regulating gene expression, i.e., TET proteins, in endometrial pathology is not yet completely known. The cells of the eutopic endometrium in women with endometriosis contain a stable, impaired methylation pattern and a histone code. Medication targeting critical genes responsible for the aberrant gene expression pattern in eutopic endometrium may help treat infertility in women with endometriosis.

Metformin Alleviates Endometriosis and Potentiates Endometrial Receptivity via Decreasing VEGF and MMP9 and Increasing Leukemia Inhibitor Factor and HOXA10

Background: Endometriosis affects endometrial receptivity, a key factor for successful embryo implantation. Metformin treatment is associated with alleviating the symptoms of endometriosis; however the mechanism of metformin action is unclear. Neoangiogenesis plays an important role in the development and recurrence of endometriosis. In addition, the leukemia inhibitor factor (LIF) and HOXA10 genes are also distinguishing markers of endometriosis (decrease) and endometrial receptivity (increase). This study investigated the therapeutic potentials of metformin and the underlying mechanism using an in vivo rat endometriosis model. Methods: Female Wistar albino mature rats with experimentally induced endometriosis were used in this study. Metformin was administered at doses of 100 mg/kg/d and 200 mg/kg/d. The volume of endometriotic implants was assessed. The protein and mRNA expression of the vascular endothelial growth factor (VEGF), matrix metalloproteinase-9 (MMP-9), the endometrial receptivity markers, LIF and HOXA10, were measured in the endometrium of rats with endometriosis. Results: Metformin treatment significantly suppressed the growth of endometriotic implants. Further, the expression of VEGF and MMP-9 protein and mRNA in endometriotic implants were significantly reduced. Metformin also significantly upregulated LIF and HOXA10 expression in endometrium from rats with endometriosis. The inhibitory effect of metformin on the growth of endometriotic implants, VEGF and MMP-9, and upregulating effect on LIF and HOXA10, was optimal at a dose of 100 mg/kg/d. Conclusion: Our in vivo data demonstrates that metformin treatment alleviates endometriosis and potentiates endometrial receptivity. The underlying mechanisms are associated with decreased expression of VEGF and MMP-9 genes and upregulation of the LIF and HOXA10 genes. The effect of metformin was optimal at 100 mg/kg/d. These findings provide a potential alternative for women with endometriosis with the potential to increase fertility. Metformin is an approved drug by FDA for diabetes and this study may add another potential clinical use for metformin.

Effects of dual inhibition of AKT and ERK1/2 pathways on endometrial pro-inflammatory, hormonal, and epigenetic microenvironment in endometriosis

Endometriosis is an estrogen-dependent and progesterone-resistant gynecological inflammatory disease of reproductive-age women. The prevalence of endometriosis is ~5-10% in reproductive-age women, increasing to 20-30% in women with subfertility. The current anti-estrogen therapies can be prescribed only for a short time because of the undesirable side effects on menstruation, pregnancy, bone health, and failure to prevent a recurrence. The causes of endometriosis-associated infertility are multifactorial and poorly understood. The objective of the present study was to determine the inhibitory effects of AKT and/or ERK1/2 pathways on the microenvironment of the endometrium in a xenograft mouse model of endometriosis of human origin. Results indicate that dual inhibition of AKT and ERK1/2 pathways, but not inhibition of either AKT or ERK1/2 pathway, suppresses the growth of the endometriotic lesions in vivo. Dual inhibition of AKT and ERK1/2 pathways suppresses the production of proinflammatory cytokines, decreases E₂ biosynthesis and signaling, and restores progesterone receptor-B signaling components in the epithelial and stromal cells of the endometrium in a cell-specific manner. These results together suggest that dual inhibition of AKT and ERK1/2 pathways suppresses the estrogen-dominant state and concomitantly increases the progesterone-responsive state of the endometrium. Therefore, dual inhibition of AKT and ERK1/2 pathways could emerge as long-term nonsteroidal therapy for endometriosis.

Investigation of HoxB3 and Growth Factors Expression in Placentas of Various Gestational Ages

An evaluation of transforming growth factor beta (TGFβ), hepatocyte growth factor (HGF), basic fibroblast growth factor (FGF-2), fibroblast growth factors receptor 1 (FGFR1) and Hox-positive cells in the human placenta, and their correlation with gestational time at delivery and pregnancy outcomes, may provide not only a better understanding of the role of Hox genes and growth factors in human development, but also may be of clinical importance in reproductive medicine. This study analyzed the immunohistochemical identification of TGFβ, HGF, FGF-2, FGFR1 and HoxB3 in placentas of various gestational ages. We found few (+) TGFβ, moderate (++) FGF-2 and numerous (+++) HGF and FGFR1 positive structures. Occasional (0/+) to numerous (+++) HoxB3-positive structures were detected in different types of placental cells specifically, cytotrophoblasts, syncytiotrophoblast, extravillous trophoblasts, and Höfbauer cells. Correlating the appearance of HoxB3 staining in placentas with neonatal parameters, we found a statistically significant negative correlation with ponderal index (r = −0.323, p = 0.018) and positive correlation with neonate body length (r = 0.541, p = 0.046). The number of HoxB3-positive cells did not correlate with growth factors and gestational age, but with neonatal anthropometrical parameters, indicating the role of HoxB3 not only in placental development, but also in the longitudinal growth of the fetus. TGFβ and FGF-2 did not play a significant role in the development of the placenta beyond 22nd week of pregnancy, while HGF and FGFR1 immunoreactive cells increased with advancing gestation, indicating increasingly evolving maturation (growth, proliferation) of the placenta, especially in the third trimester.

Estrogen- and Progesterone (P4)-Mediated Epigenetic Modifications of Endometrial Stromal Cells (EnSCs) and/or Mesenchymal Stem/Stromal Cells (MSCs) in the Etiopathogenesis of Endometriosis

Endometriosis is a common chronic inflammatory condition in which endometrial tissue appears outside the uterine cavity. Because ectopic endometriosis cells express both estrogen and progesterone (P4) receptors, they grow and undergo cyclic proliferation and breakdown similar to the endometrium. This debilitating gynecological disease affects up to 15% of reproductive aged women. Despite many years of research, the etiopathogenesis of endometrial lesions remains unclear. Retrograde transport of the viable menstrual endometrial cells with retained ability for attachment within the pelvic cavity, proliferation, differentiation and subsequent invasion into the surrounding tissue constitutes the rationale for widely accepted implantation theory. Accordingly, the most abundant cells in the endometrium are endometrial stromal cells (EnSCs). These cells constitute a particular population with clonogenic activity that resembles properties of mesenchymal stem/stromal cells (MSCs). Thus, a significant role of stem cell-based dysfunction in formation of the initial endometrial lesions is suspected. There is increasing evidence that the role of epigenetic mechanisms and processes in endometriosis have been underestimated. The importance of excess estrogen exposure and P4 resistance in epigenetic homeostasis failure in the endometrial/endometriotic tissue are crucial. Epigenetic alterations regarding transcription factors of estrogen and P4 signaling pathways in MSCs are robust in endometriotic tissue. Thus, perspectives for the future may include MSCs and EnSCs as the targets of epigenetic therapies in the prevention and treatment of endometriosis. Here, we reviewed the current known changes in the epigenetic background of EnSCs and MSCs due to estrogen/P4 imbalances in the context of etiopathogenesis of endometriosis. Graphical Abstract.

Low-dose aspirin can downregulate progesterone resistance and increase the expression of LIF in endometriosis during the implantation window

AIM

Study the effect of low-dose aspirin on the endometrial receptivity in endometriosis rat models.

MATERIALS AND METHODS

This study is to explore the expressions of progesterone receptor and LIF among three groups of endometriosis rat models: control group (n = 12), EMs group (n = 15), and aspirin group (n = 17). The expressions of progesterone receptor (PR), PRA, PRB, and leukemia inhibitory factor receptor (LIFR) in eutopic endometrium were determined using immunohistochemistry technology, western blot, and qRT-PCR. The levels of LIF in eutopic endometrium and serum were detected by western blot, qRT-PCR, and ELISA.

RESULTS

The expressions of PR, PRA, and PRB protein were significantly increased in the eutopic endometrium after low-dose aspirin treatment, and the level of PRB mRNA was also increased while the ratio of PRA/PRB mRNA was decreased in the eutopic endometrium. The levels of LIF in eutopic endometrium and serum were increased compared with the untreated endometriosis rats. However, the expression of LIFR was not statistically different among the three groups.

CONCLUSIONS

The results suggest that the low-dose aspirin treatment could downregulate progesterone resistance and increase the expression of LIF of endometriosis rats during the implantation window, which could improve endometrial receptivity and enhance the pregnant rate of endometriosis. It may provide a potential treatment method for endometriosis-related infertility.

Endometriosis and Medical Therapy: From Progestogens to Progesterone Resistance to GnRH Antagonists: A Review

Background: The first objective of this review was to present, based on recent literature, the most frequently applied medical options (oral contraceptive pills (OCPs) and progestogens) for the management of symptomatic endometriosis, and evaluate their effectiveness in treating premenopausal women with endometriosis-associated pelvic pain, dysmenorrhea, non-menstrual pelvic pain and dyspareunia. The second objective was to review the concept of progesterone resistance and newly available treatment options. Methods: We reviewed the most relevant papers (n = 73) on the efficacy of OCPs and progestogens as medical therapy for endometriosis, as well as those on progesterone resistance and new medical alternatives (oral gonadotropin-releasing hormone (GnRH) antagonist). Eleven papers, essentially reviews, were selected and scrutinized from among 94 papers discussing the concept of progesterone resistance. Results: Having reviewed the most significant papers, we can confirm that OCPs and progestogens are effective in two-thirds of women suffering from endometriosis, but that other options are required in case of failure (in one-third of women due to progesterone resistance) or intolerance to these compounds. It is clear that there is a need for effective long-term oral treatment capable of managing endometriosis symptoms, while mitigating the impact of side effects. Biochemical, histological and clinical evidence show that estrogens play a critical role in the pathogenesis of endometriosis, so lowering levels of circulating estrogens should be considered an effective medical approach. The efficacy of three oral GnRH antagonists is discussed on the basis of published studies. Conclusion: There is a place for GnRH antagonists in the management of symptomatic endometriosis and clinical trials should be conducted, taking into account the different phenotypes in order to propose novel algorithms.

Revisiting estrogen-dependent signaling pathways in endometriosis: Potential targets for non-hormonal therapeutics

Endometriosis is an estrogen-dependent gynecologic disease. Endometriotic cells survive in oxidative stress and hypoxic environments. The aim of this review is to reconsider new therapeutic strategies for endometriosis by focusing on estrogen signaling, ROS production and scavenging, and mitochondrial metabolism. Each keyword alone or in combination was used to search from PubMed and Embase by applying the filters of the title and the publication years between January 2000 and May 2020. Abnormal epigenetic marks of estrogen receptors (ERs) in endometriosis cause overexpression of ERβ, progesterone resistance, inflammation, anti-apoptosis, and mitochondrial metabolic modification. In addition to hormonal action, estrogen is involved in various functions such as mitochondrial biosynthesis and energy metabolism. Estrogen works with its downstream target genes to modulate mitochondrial gene expression, regulate ROS production, and affect mitochondrial biology, including ATP production, antioxidant defenses, mitochondrial biosynthesis, quality control, and energy-transducing capacity. Endometriosis can shift mitochondrial metabolism from oxidative phosphorylation to aerobic glycolysis. This metabolic conversion suppresses ROS production and thus activates the survival signal of endometriotic cells. Therefore, molecules associated with aerobic glycolysis and mitochondrial metabolism are considered therapeutic targets for endometriosis. In conclusion, estrogen downstream target genes involved in mitochondrial metabolic biosynthesis may be potential targets for non-hormonal treatment of endometriosis.

Insight into epigenetics of human endometriosis organoids: DNA methylation analysis of HOX genes and their cofactors

OBJECTIVE

To evaluate and compare the methylation pattern of Human Homeobox (HOX) clusters (A-D) and HOX cofactors in normal, eutopic, and ectopic endometrial tissues with ectopic and eutopic endometriosis organoids as advanced preclinical research models.

DESIGN

A chromatin immunoprecipitation (ChIP) array containing 84 genes was used to analyze methylation levels of HOX clusters (A-D) and HOX cofactors in normal, eutopic, and ectopic endometrial biopsy specimens as well as ectopic and eutopic endometriosis organoids.

SETTING

Reproductive biomedicine and cell science research centers.

PATIENT(S)

Nine healthy women without endometriosis (control) and 16 women diagnosed with endometriosis.

INTERVENTION(S)

Ectopic endometrial lesions were obtained using a laparoscopic procedure, and eutopic and control endometrium biopsy specimens were obtained using pipelle sampling.

MAIN OUTCOME MEASURE(S)

Methylation levels of HOX clusters (A-D) and HOX cofactors in eutopic and ectopic endometrial biopsy specimens, as well as eutopic and ectopic endometriosis organoids and normal endometrium.

RESULT(S)

Most HOX clusters (A-D) and HOX cofactors showed methylation alterations in ectopic/eutopic endometrial tissues and ectopic/eutopic endometriosis organoids compared with normal endometrium. These methylation alterations had the same pattern in ectopic/eutopic tissue biopsy specimens and ectopic/eutopic endometriosis organoids in most genes. A contrariwise methylation pattern was observed in 28 of 84 genes in the ectopic/eutopic tissue biopsy specimens and ectopic/eutopic endometriosis organoids.

CONCLUSION(S)

Because a conserved pattern of methylation alterations in endometriosis tissues and organoids was observed for most of the investigated genes (56 of 84), it can be concluded that endometriosis organoids maintain epigenetic changes. Therefore, our study suggests endometriosis organoids as a novel preclinical model to determine the epigenetic mechanisms that underlie endometriosis.

Study of the Characterization of Side Population Cells in Endometrial Cancer Cell Lines: Chemoresistance, Progestin Resistance, and Radioresistance

Introduction: Radiotherapy, combined regimens as platinum-paclitaxel chemotherapy and/or endocrine therapy is an important adjuvant treatment after surgery for endometrial cancer (EC). While, the resistance to them remain unclear. In our study, to separate the characteristics of side population (SP) cells from EC cell lines, study the mechanism of Taxol-resistance, progestin resistance and radioresistanc, and provide the basic for EC.

Methods: SP cells from EC cell lines HEC-1A, Ishikawa and RL95-2 were separated by Hoechst 33342 staining and flow cytometry analysis. The expression of breast cancer resistance protein (BCRP) in SP cells and non-SP cells from HEC-1A was examined by immunocytochemistry, and the radiation-resistant and Taxol-resistant characteristics of SP cells and non-SP cells were compared by MTS. Ishikawa, Ishikawa-SP, and Ishikawa-non-SP cells incubated with MPA were selected for cell apoptosis assays by using flow cytometry. The expression of caspase-3 was examined by immunocytochemistry, and autophagy was detected by MDC staining.

Results: Small proportions of SP cells, namely, 1.44 ± 0.93%, 2.86 ± 3.09%, and 2.87 ± 1.29%, were detected in HEC-1A, Ishikawa and RL95-2, respectively. There was a stronger clone formation efficiency for the SP cells than for non-SP cells in HEC-1A [(6.02 ± 1.17) vs. (0.53±0.20)%, P = 0.001], and there was a significant difference in the rate of tumourigenicity between the SP cells and non-SP cells in HEC-1A (87.5 vs. 12.5%). There were higher levels of BCRP expression (P = 0.001) and resistance to Taxol and radiation (P < 0.05) in the SP cells than in non-SP cells. After MPA treatment, the apoptosis rates were significantly different among the Ishikawa, Ishikawa-SP and Ishikawa-non-SP groups [(4.64 ± 0.18)%, (4.01 ± 0.43)%, and (9.3 ± 0.67)%; (P = 0.05)], and the expression of Caspase-3 in the Ishikawa group was higher than that in Ishikawa-SP group. The autophagic activity of the Ishikawa-SP cells was the strongest, while the autophagic activity of Ishikawa-non-SP was the weakest.

Conclusions: There is a significant enrichment in SP cells among different EC cell lines, and these SP cells be more resistant to Taxol, MPA and radiation therapy. The overexpression of BCRP among SP cells may be the cause of resistance to Taxol, progestin and radiotherapy, which may be related to apoptosis and autophagic activity.

Progesterone's role in deep infiltrating endometriosis: Progesterone receptor and estrogen metabolism enzymes expression and physiological changes in primary endometrial stromal cell culture

To study progesterone signaling activation, we measured changes in extracellular pH as a reflection of Na+/H+ exchange (NHE) using a cytosensor microphysiometer and assessed progesterone receptor (PR) and estrogen metabolism enzymes mRNA expression in cultured endometrial cells from women with deep infiltrating endometriosis and healthy controls using real-time quantitative PCR. This study was conducted at a University hospital and included patients with and without deep infiltrating endometriosis (DIE). Primary endometrial stromal cells (ECs) from women with DIE and controls were treated with 17β-estradiol and progesterone prior to microphysiometer measurements and qPCR evaluations. Decreased progesterone responsiveness and decreased total nuclear PR and HSD17B1 mRNA expression were observed in cultured ECs from women with deep infiltrating endometriosis relative to those from control samples before and after hormone treatment. These cells also showed increased 17β-hydroxysteroid dehydrogenases types 2 (HSD17B2) relative to control group and increased expression of aromatase (CYP19) after exposure to progesterone. These physiological and expression patterns observed in ECs cultures from women with DIE reinforces previous findings in the literature supporting the progesterone resistance hypothesis in the pathogenesis of endometriosis.

Characterization of cell fusion in an experimental mouse model of endometriosis†

Cell fusion is involved in the development of some adult organs, is implicated in the pathogenesis of specific types of cancer, and is known to participate in repair/regeneration processes mediated by bone-marrow-derived cells (BMDCs). Endometriosis is a disease characterized by growth of functional endometrial tissue outside of the uterine cavity. Endometriosis shares some molecular properties with cancer and BMDCs home to endometriosis lesions in a mouse model. Our objective was to determine if cell fusion can occur in endometriosis and establish whether bone-marrow-derived cells participate in cell fusion events in lesions. We employed a Cre-Lox system to identify cell fusion events in a mouse model of endometriosis. Fused cells were detected in endometriotic lesions, albeit at a low frequency (∼1 in 400 cells), localized to the stromal compartment, and displayed restricted proliferation. Using 5-fluorouracil-based nongonadotoxic bone marrow transplantation model, we demonstrate that bone marrow cells represent a principal cell source for fusion events in lesions. Cell fusion progeny uniformly lacked expression of selected markers of hematopoietic, endothelial, and epithelial markers, though they expressed the mesenchymal/stromal markers Sca-1 and CD29. This study is the first to describe the phenomenon of cell fusion in endometriosis and points to a mesenchymal population derived from cell fusion events with limited proliferative activity, properties previously attributed to endometrial stem cells. Their putative role in the pathogenesis of the disease remains to be elucidated.

Large, Non-Cavity Distorting Intramural Leiomyomas Decrease Leukemia Inhibitory Factor in the Secretory Phase Endometrium

Despite mounting evidence that large intramural leiomyomas decrease fecundity during in vitro fertilization cycles, few studies have demonstrated a mechanism for this impact. We hypothesize that large intramural leiomyomas (IM) decrease the expression of endometrial implantation factors during the window of implantation. We prospectively recruited sub-fertile patients with IM 3 cm or greater in size planning myomectomy and performed endometrial biopsies the day of planned myomectomy (n = 9). Preoperative screening demonstrated no intercavitary lesions. Control endometrial samples were obtained from young, normally menstruating women free of uterine leiomyomas (n = 8). Endometrial samples were obtained in the mid-secretory phase (average cycle day for control patients and intramural leiomyoma patients were 24.5 and 21.3, respectively). Expression of implantation markers HOXA10, leukemia inhibitory factor (LIF), ER-α, and PR was compared using quantitative immunohistochemistry. Standard descriptive statistics were used to compare H-scores between the cohorts. Patients with intramural leiomyomas were found to have decreased LIF compared to controls (p value < 0.001). Expressions of HOXA10 and PR were no different between cohorts; however, ER-α showed a trend toward increased expression in the fibroid cohort (p value 0.07). LIF is downregulated in the endometrium of patients with large IM. This study is among the first to show decreased LIF expression in patients with uterine leiomyomas. We hypothesize that this difference from previously published work is due to sampling the endometrium at the height of LIF expression. Further work is needed to show if LIF downregulation is corrected with leiomyoma resection.

Clinical Outcome Analysis and Correlation of Reproductive Outcome with Endometriosis Fertility Index in Laparoscopically Managed Endometriosis Patients: A Retrospective Cohort Study

Background:

Laparoscopy is important for management of endometriosis patients with estimation of endometriosis fertility index (EFI) which can predict reproductive outcome.

Aims:

This study aims to evaluate clinical outcome in laparoscopically managed pelvic endometriosis and correlation of reproductive outcome with EFI.

Setting and Design:

Retrospective cohort study carried out in the Department of Obstetrics and Gynecology.

Materials and Methods:

Our study included 123 patients who had undergone laparoscopic management of endometriosis from January 2017 to March 2018. Case files were retrieved and meticulously analyzed. All patients were contacted and interviewed. Symptomatic relief and pregnancy in infertility patients were recorded. EFI was calculated.

Statistical Analysis:

Data analyses were carried out using statistical software STATA version 12.0. P < 0.05 was considered statistically significant.

Results and Conclusions:

A total of 123 cases were enrolled; the most common complaint was infertility 107 (86.99%); the mean age was 32.4 years. EFI was found to be (6 to 10) in 28(26.2%) patients, EFI of (4 to 5) in 49 (45.8%) and EFI of (0 to 3) in 30 (28.0%). Post surgery, dysmenorrhoea was relieved in 56 (65.88%) patients, menstrual irregularities were relieved in 45 (76.27 %) patients, dyspareunia in 32 (54.24%) and chronic pelvic pain in 24 (40.5%) patients. 8 (40%) patients with low EFI conceived, 20 (58.82%) with moderate, and 26 (96.29%) with high EFI conceived. EFI score showed statistically significant positive correlation with pregnancy outcome P = 0.001, higher the EFI score, better the reproductive outcome. Laparoscopic surgeries are important for managing patients of endometriosis. It provides significant symptomatic relief, and EFI estimation can be done, which is a good tool to predict reproductive outcome of infertility patients with endometriosis.

Up-regulation of HOXB cluster genes are epigenetically regulated in tamoxifen-resistant MCF7 breast cancer cells

Tamoxifen (TAM) is commonly used to treat estrogen receptor (ER)-positive breast cancer. Despite the remarkable benefits, resistance to TAM presents a serious therapeutic challenge. Since several HOX transcription factors have been proposed as strong candidates in the development of resistance to TAM therapy in breast cancer, we generated an in vitro model of acquired TAM resistance using ER-positive MCF7 breast cancer cells (MCF7-TAMR), and analyzed the expression pattern and epigenetic states of HOX genes. HOXB cluster genes were uniquely up-regulated in MCF7-TAMR cells. Survival analysis of in slico data showed the correlation of high expression of HOXB genes with poor response to TAM in ER-positive breast cancer patients treated with TAM. Gain- and loss-of-function experiments showed that the overexpression of multi HOXB genes in MCF7 renders cancer cells more resistant to TAM, whereas the knockdown restores TAM sensitivity. Furthermore, activation of HOXB genes in MCF7-TAMR was associated with histone modifications, particularly the gain of H3K9ac. These findings imply that the activation of HOXB genes mediate the development of TAM resistance, and represent a target for development of new strategies to prevent or reverse TAM resistance.

DNA Methylation Inhibitor 5-Aza-2'-Deoxycytidine Modulates Endometrial Receptivity Through Upregulating HOXA10 Expression

Endometrial receptivity is a critical factor for embryo implantation. A decrease in endometrial homeobox A10 (HOXA10) expression is associated with hypermethylation of its promoter and lower endometrial receptivity in animals and humans. 5-Aza-2'-deoxycytidine (AZA) is a DNA methyltransferase inhibitor. However, whether demethylation of the HOXA10 gene could increase the receptivity of the human endometrium remains unknown. Homeobox A10 promoter methylation was analyzed using bisulfite genomic sequencing polymerase chain reaction. Quantitative real time polymerase chain reaction and Western blotting were used to analyze the expression of HOXA10 and its downstream target genes (integrin subunit β 3 [ITGB3] and insulin growth factor binding protein 1 [IGFBP1]) in Ishikawa cells treated with or without AZA for 24 hours. Their protein expression was analyzed with or without HOXA10 siRNA treatment. The effect of AZA on embryo implantation was examined using a Jeg-3 spheroid-endometrial cell attachment assay. The percentage of methylated CpG islands in the HOXA10 promoter was 72.0% without AZA treatment. However, it was 38% and 35% in the 1 and 10 μM AZA treatment groups, respectively. 5-Aza-2'-deoxycytidine strongly induced the expression of HOXA10, ITGB3, and IGFBP1 messenger RNA and their protein expression. Homeobox A10 knockdown led to decreased expression of HOXA10, ITGB3, and IGFBP1, with or without AZA treatment. The attachment rate of Jeg-3 spheroids increased significantly from 82% (control) to 95% (AZA 1 μM) and 96% (AZA 10 μM) after AZA treatment. 5-Aza-2'-deoxycytidine could upregulate the expression of ITGB3 and IGFBP1 via HOXA10 upregulation, and upregulation of ITGB3 and IGFBP1 plays an important role in endometrial receptivity during implantation. 5-Aza-2'-deoxycytidine may improve endometrial receptivity by upregulating the expression of HOXA10.

Progesterone Receptor Status Predicts Response to Progestin Therapy in Endometriosis

Context

Progestin-based therapy is the first-line treatment for managing endometriosis-associated pain. However, response to progestins is currently variable and unpredictable. Predictive markers for response to progestin-based therapy would allow for a personalized approach to endometriosis treatment.

Objective

We hypothesize that progesterone receptor (PR) levels in endometriotic lesions determine response to progestin-based therapy.

Design

Retrospective cohort study.

Setting

Academic center.

Patients

Fifty-two subjects with histologically confirmed endometriosis and a previous documented response to hormonal therapy were included.

Interventions

Immunohistochemistry was performed on sections of endometriotic lesions using a rabbit polyclonal IgG for detection of PR-A/B.

Main Outcome Measures

The Histo (H)-score was used for quantifying PR status. Response to progestin-based therapies was determined from review of the electronic medical record.

Results

H-score was higher in responders compared with nonresponders. Subjects were categorized into three groups: high (H-score > 80, n = 7), medium (H-score 6 to 80, n = 28), and low (H-score ≤ 5, n = 17) PR status. The threshold of PR > 80 was associated with a 100% positive predictive value. The threshold of PR < 5 was associated with a 94% negative predictive value.

Conclusion

PR status is strongly associated with response to progestin-based therapy. Receptor status in endometriosis could be used to tailor hormonal-based regimens after surgery, and negate trialing progestin-based therapy to determine resistance. Ascertainment of PR status may allow for a novel, targeted, precision-based approach to treating endometriosis.

Decay-accelerating factor promotes endometrial cells proliferation and motility under ovarian hormone stimulation

The intent of the study was to explore the elevating expression of decay-accelerating factor(DAF) exerts influence on biological behaviors of endometrial stromal cells except in classical immunology on the basis of bioinformatic statistics and clinical miscarriages findings suggesting its potential role in the establishment of endometrial receptivity. We confirmed that DAF locates on the cellular surface of endometrial epithelium and stroma. By using plasmid transfection to down-regulate DAF expression in primary endometrial stromal cells(ESCs), we discovered that DAF expression in ESCs increases in response to estradiol and progesterone stimulation in dose- and time-dependent manners; moreover, tamoxifen and RU486 stimulations to block estrogen receptors(ERs) and progesterone receptors(PRs) respectively result in reduced DAF mRNA and protein, and it is more obvious to block PRs. Meanwhile, knocked-down DAF in ESCs weakens the proliferation, migration and invasion of endometrial cells. Cell cycle analysis showed knocked-down DAF accumulates cells in S phase and diminishes cells in G0/G1 phase, which substantiates DAF mediates endometrial cells proliferation. In conclusion, DAF is a potential molecule involving in endometrial cellular proliferation and motility to verify up-expressed DAF during the WOI may facilitate endometrial physiobiological behavior changes, which shed light on DAF function and potential role in the endometrial receptivity establishment.

G-Protein-Coupled Receptor CXCR7 Is Overexpressed in Human and Murine Endometriosis

Endometriosis is a chronic inflammatory disease. Dysfunctional regulation of chemokines and chemokine receptors is a crucial aspect of endometriosis pathogenesis. Chemokine G-protein-coupled receptors (GPCRs) are important drug targets that regulate inflammation and immunity. Recently, CXCR7, a C-X-C motif containing GPCR, has been identified as a receptor for chemokine ligand CXCL12, one of the best characterized chemokines for cell trafficking, angiogenesis, and cell proliferation in cancer and inflammation. Here, we investigated the expression and localization of CXCR7 in human endometriosis and a murine model of the disease. Normal endometrial epithelium and stroma showed undetectable or very low expression of CXCR7, without any significant changes across phases of the menstrual cycle in humans. CXCR7 is significantly upregulated in endometriosis, showing higher staining in glands and in associated vessels. The mouse model recapitulated the human findings. In conclusion, overexpression of CXCR7 in different cellular populations of endometriosis microenvironment may play a role in the pathogenesis and represent a novel target for treatment.

Predictive Biomarkers May allow Precision Therapy of Endometriosis

Introduction

Endometriosis is a chronic inflammatory gynecological disorder that causes pelvic pain. Due to the heterogeneity of the disease, response to any treatment in an individual is variable. We aimed to develop in vitro testing that could be adapted for use in precision therapy for endometriosis. We piloted a personalized medicine approach by identifying predictive biomarkers while determining the effect of bazedoxifene (BZA) and medroxyprogesterone acetate (MPA) on the gene expression of a progesterone receptor (PR), an estrogen receptor (ER), and an aromatase (CYP19A1) enzyme in cells cultured from biopsies of endometriosis patients. The differential expression of the most common molecular targets in endometriosis therapy correlated with cellular response.

Methods

Primary eutopic endometrial stromal cells were cultured from endometrial biopsies obtained in secretory phase from women between 24 and 42 years old with moderate-to-severe endometriosis (stages III and IV). Exclusion criteria included use of hormonal treatments and intrauterine contraception in the 6 months prior to surgery. Cells were treated either with BZA, MPA, or vehicle control. Total RNA was extracted from the treated and untreated cells. Differential expression of genes that are involved in the pathogenesis of endometriosis was determined by quantitative reverse transcriptase-polymerase chain reaction analysis.

Results

After determining the baseline expression levels of PRA/B, ERα and CYP19A1, response to treatment was monitored using Ki-67 as a marker of cell proliferation. MPA was effective in blocking proliferation in the group expressing high levels of PRA/B. Endometrium expressing high levels of CYP19A1 preferentially responded to BZA, a selective estrogen receptor modulator known to block estrogen action in endometrium.

Conclusions

PR expression may predict progestin resistance in endometriosis while CYP19A1 expression may indicate the need to block estrogen signaling.

Research Priorities for Endometriosis

The 3rd International Consensus Workshop on Research Priorities in Endometriosis was held in São Paulo on May 4, 2014, following the 12th World Congress on Endometriosis. The workshop was attended by 60 participants from 19 countries and was divided into 5 main sessions covering pathogenesis/pathophysiology, symptoms, diagnosis/classification/prognosis, disease/symptom management, and research policy. This research priorities consensus statement builds on earlier efforts to develop research directions for endometriosis. Of the 56 research recommendations from the 2011 meeting in Montpellier, a total of 41 remained unchanged, 13 were updated, and 2 were deemed to be completed. Fifty-three new research recommendations were made at the 2014 meeting in Sao Paulo, which in addition to the 13 updated recommendations resulted in a total of 66 new recommendations for research. The research recommendations published herein, as well as those from the 2 previous papers from international consensus workshops, are an attempt to promote high-quality research in endometriosis by identifying and agreeing on key issues that require investigation. New areas included in the 2014 recommendations include infertility, patient stratification, and research in emerging nations, in addition to an increased focus on translational research. A revised and updated set of research priorities that builds on this document will be developed at the 13th World Congress on Endometriosis to be held on May 17-20, 2017, in Vancouver, British Columbia, Canada.

A Preliminary Communication: Ongoing Study on HOXA10 Methylation Profile of Endometriosis Patients with Infertility

Background

Endometriosis and infertility have been shown to be related to one another. The mechanisms that explain this phenomenon are not fully understood. One of the possible mechanisms of infertility in endometriosis patients is failure of implantation of the embryo in the endometrium. This may be caused by high levels of methylation of HOXA10 gene in patients with endometriosis, resulting a decrease in the expression of genes that play a role in this endometrial receptivity.

Objective

To determine the methylation profile of HOXA10 gene on eutopic endometrium in endometriosis patients with infertility.

Methods

This is a cross-sectional study conducted at Cipto Mangunkusumo General Hospital from July 2015 to July 2016. The subjects of research were cystic ovarian endometriosis patients with infertility, confirmed histopathologically and non-endometriosis-fertile patients. The methylation status of HOXA 10 gene in both groups was examined and compared. Statistical analysis is Mann-Whitney U-test, a two-tailed p value less than 0.05 was considered significant.

Results

There were six endometriosis patients and six controls. Six samples on endometriosis group showed the following percentage rate of methylation: 63.29%, 55.28%, 33.92%, 43.27%, 77.20% and 65.94%. Meanwhile, four samples in the control group did not undergo methylation at all and two other samples methylated at low levels equal to 15.24% and 16.48%. Methylation status between these two groups is statistically different with p 0.03.

Conclusions

In patients with endometriosis-associated infertility, HOXA10 gene in eutopic endometrium has a higher methylation level.

Endometrial Expression of Steroidogenic Factor 1 Promotes Cystic Glandular Morphogenesis

Epigenetic silencing of steroidogenic factor 1 (SF1) is lost in endometriosis, potentially contributing to de novo local steroidogenesis favoring inflammation and growth of ectopic endometrial tissue. In this study, we examine the impact of SF1 expression in the eutopic uterus by a novel mouse model that conditionally expresses SF1 in endometrium. In vivo SF1 expression promoted the development of enlarged endometrial glands and attenuated estrogen and progesterone responsiveness. Endometriosis induction by autotransplantation of uterine tissue to the mesenteric membrane resulted in the increase in size of ectopic lesions from SF1-expressing mice. By integrating the SF1-dependent transcriptome with the whole genome binding profile of SF1, we identified uterine-specific SF1-regulated genes involved in Wingless and Progesterone receptor-Hedgehog-Chicken ovalbumin upstream promoter transcription factor II signaling for gland development and epithelium-stroma interaction, respectively. The present results indicate that SF1 directly contributes to the abnormal uterine gland morphogenesis, an inhibition of steroid hormone signaling and activation of an immune response, in addition to previously postulated estrogen production.

Clinical management of endometriosis-associated infertility

Endometriosis is a common chronic benign disease that affects reproductive age women and causes chronic pelvic pain and infertility. Despite its prevalence, the exact mechanisms of the pathogenesis of endometriosis-associated infertility are unknown, and precise standards of management have not yet been established. Medical and surgical treatments for endometriosis have different effects on the chance of conception, either spontaneously or via assisted reproductive technologies (ART). In this manuscript, we review the literature from years 1979 to 2015 to report on the proposed mechanism of endometriosis-associated infertility, the staging system of endometriosis for pregnancy outcomes and the current management of patients with endometriosis-associated infertility.

Aberrant HOXA10 Methylation in Patients With Common Gynecologic Disorders: Implications for Reproductive Outcomes

HomeoboxA10 (HOXA10) is a transcription factor that is crucial for the development and patterning of the uterus during embryogenesis. In the adult endometrium, HOXA10 expression is regulated by steroid hormones and embryonic signals. Expression of sufficient HOXA10 messenger RNA is essential to endometrial receptivity and embryo implantation. Aberrant methylation is believed to alter the expression of HOXA10. Methylation of this gene may be associated with decreased fertility, implantation defects, and/or reproductive wastage seen in certain disease states that affect the female reproductive tract. This study describes the differences in methylation patterns of HOXA10 gene in uterine myomas, endometriosis, uterine septum, Asherman syndrome, or uterine polyps of women undergoing hysteroscopic surgery. In the endometrium of uteri with polyps, submucosal myomas, and intramural myomas, there were CpG sites within the HOXA10 gene that were highly methylated compared to controls. The HOXA10 gene in women with endometriosis was hypomethylated compared to controls. DNA methylation may be a common molecular mechanism that results in reproductive dysfunction seen in gynecologic disease.

Endometriosis Located Proximal to or Remote From the Uterus Differentially Affects Uterine Gene Expression

The mechanisms that lead to the altered uterine gene expression in women with endometriosis are poorly understood. Are these changes in gene expression mediated by proximity to endometriotic lesions or is endometriosis a systemic disease where the effect is independent of proximity to the uterus? To answer this question, we created endometriosis in a murine model either in the peritoneal cavity (proximal) or at a subcutaneous remote site (distal). The expression of several genes that are involved in endometrial receptivity (homeobox A10 [Hoxa10], homeobox A11 [Hoxa11], insulin-like growth factor binding protein 1 [Igfbp1], Kruppel-like factor 9 [Klf9], and progesterone receptor [Pgr]) was measured in the eutopic endometrium of mice transplanted with either proximal or distal endometriosis lesions. Decreased expression of Hoxa10, Igfbp1, Klf9, and total Pgr genes was observed in the eutopic endometrium of mice with peritoneal endometriosis. In the mice with distal lesions, overall expression of these genes was not as severely affected, however, Igfbp1 expression was similarly decreased and the effect on Pgr was more pronounced. Endometriosis does have a systemic effect that varies with distance to the end organ. However, even remote disease selectively and profoundly alters the expression of genes such as Pgr. This is the first controlled experiment demonstrating that endometriosis is not simply a local peritoneal disease. Selective alteration of genes critical for endometrial receptivity and endometriosis propagation may be systemic. Similarly, systemic effects of endometriosis on other organs may also be responsible for the widespread manifestations of the disease.

A current view of the role of epigenetic changes in the aetiopathogenesis of endometriosis

The purpose of the study was to examine the role of epigenetic changes in the aetiopathogenesis of endometriosis. The analysis and review of the relevant current literature in English language related to the role of epigenetic changes in the aetiopathogenesis of endometriosis. Epigenetic changes are common denominators for hormonal, immunological and inflammatory aberrations which play a key role in the aetiopathogenesis of endometriosis. Many internal and external factors may cause the different running of the epigenetic mechanism. As yet fully unknown genetic factors may increase the sensitivity of the epigenetic mechanism to various internal and external factors. The breakdown of epigenetic regulation is the main factor initiating the pathogenetic mechanisms for endometriosis formation.

Neonatal Progesterone Programs Adult Uterine Responses to Progesterone and Susceptibility to Uterine Dysfunction

In this report, we investigated the consequences of neonatal progesterone exposure on adult rat uterine function. Female pups were subcutaneously injected with vehicle or progesterone from postnatal days 3 to 9. Early progesterone exposure affected endometrial gland biogenesis, puberty, decidualization, and fertility. Because decidualization and pregnancy success are directly linked to progesterone action on the uterus, we investigated the responsiveness of the adult uterus to progesterone. We first identified progesterone-dependent uterine gene expression using RNA sequencing and quantitative RT-PCR in Holtzman Sprague-Dawley rats and progesterone-resistant Brown Norway rats. The impact of neonatal progesterone treatment on adult uterine progesterone responsiveness was next investigated using quantitative RT-PCR. Progesterone resistance affected the spectrum and total number of progesterone-responsive genes and the magnitude of uterine responses for a subset of progesterone targets. Several progesterone-responsive genes in adult uterus exhibited significantly dampened responses in neonatally progesterone-treated females compared with those of vehicle-treated controls, whereas other progesterone-responsive transcripts did not differ between female rats exposed to vehicle or progesterone as neonates. The organizational actions of progesterone on the uterus were dependent on signaling through the progesterone receptor but not estrogen receptor 1. To summarize, neonatal progesterone exposure leads to disturbances in endometrial gland biogenesis, progesterone resistance, and uterine dysfunction. Neonatal progesterone effectively programs adult uterine responsiveness to progesterone.

Laparoscopic endometrioma resection increases peri-implantation endometrial HOXA-10 and HOXA-11 mRNA expression

OBJECTIVE

To determine whether laparoscopic endometrioma resection alters peri-implantation endometrial HOXA-10, HOXA-11, LIF, ITGB3 and ITGAV mRNA expression.

DESIGN

Case-control study.

SETTING

Medical school.

PATIENT(S)

Twenty infertile patients with uni- or bilateral endometrioma, five infertile patients having nonendometriotic benign ovarian cyst, and five fertile control subjects.

INTERVENTION(S)

Mid-luteal-phase endometrial sampling was performed at the time of surgery. Second endometrial biopsies were obtained 3 months after laparoscopic endometrioma resection during the mid-luteal phase of the cycle.

MAIN OUTCOME MEASURE(S)

Endometrial HOXA-10, HOXA-11, LIF, ITGAV, and ITGB3 mRNA expressions were evaluated with the use of reverse-transcription polymerase chain reaction.

RESULT(S)

Significantly decreased endometrial ITGAV mRNA expression was noted in biopsies obtained from endometrioma and nonendometriotic cyst groups before surgery. Trends toward decreased endometrial HOXA-10, HOXA-11, LIF, and ITGB3 mRNA expressions were noted in the endometrioma and nonendometriotic cyst groups before surgery compared with the fertile subjects. However, the differences failed to show statistical significance. Compared with preoperative values, significantly increased HOXA-10 (12.1-fold change) and HOXA-11 (17.2-fold change) mRNA expressions were noted in endometrial biopsies obtained from subjects who were undergoing endometrioma surgery. Fold change in endometrial ITGAV mRNA after endometrioma surgery was found to be 30.1 and indicated a positive regulation. However, this fold increase was statistically insignificant. Expressions of these endometrial receptivity markers did not change significantly after surgical removal of nonendometriotic benign ovarian cysts.

CONCLUSION(S)

Laparoscopic endometrioma resection increases peri-implantation endometrial HOXA-10 and HOXA-11 mRNA expression, suggesting an improvement in endometrial receptivity.

Hox transcription factors: modulators of cell-cell and cell-extracellular matrix adhesion

Hox genes encode homeodomain-containing transcription factors that determine cell and tissue identities in the embryo during development. Hox genes are also expressed in various adult tissues and cancer cells. In Drosophila, expression of cell adhesion molecules, cadherins and integrins, is regulated by Hox proteins operating in hierarchical molecular pathways and plays a crucial role in segment-specific organogenesis. A number of studies using mammalian cultured cells have revealed that cell adhesion molecules responsible for cell-cell and cell-extracellular matrix interactions are downstream targets of Hox proteins. However, whether Hox transcription factors regulate expression of cell adhesion molecules during vertebrate development is still not fully understood. In this review, the potential roles Hox proteins play in cell adhesion and migration during vertebrate body patterning are discussed.

Regulation of myeloid ecotropic viral integration site 1 and its expression in normal and abnormal endometrium

OBJECTIVE

To identify the expression profile and sex steroid regulation pattern of myeloid ecotropic viral integration site 1 (MEIS1) in endometrium.

DESIGN

Molecular studies in human and animal tissue.

SETTING

Reproductive medicine center of a university hospital.

PATIENT(S) AND ANIMAL(S)

Women with normal menstrual cycles for male infertility and female infertility with endometriosis. Sexually mature female mice (Kunming White strain).

INTERVENTION(S)

Primary cultured endometrial stromal cells, Ishikawa cells, and oophorectomized mice were treated with sex steroid.

MAIN OUTCOME MEASURE(S)

MEIS1 expression in the human endometrium during the menstrual cycle, mouse uterus during the peri-implantation period of pregnancy, and eutopic endometrium from patients with endometriosis was analyzed by immunohistochemistry staining and western blot. In addition, MEIS1 expression in response to sex steroid was examined both in vitro and in vivo by immunohistochemistry staining and western blot.

RESULT(S)

MEIS1 expression was markedly increased in endometrium during the implantation period, and in decidualizing stromal cells in human endometrium and murine uterus. Steroid hormones increased MEIS1 expression in primary cultured endometrial stromal cells, Ishikawa cells, and endometrium of oophorectomized mice. The effects of estrogen and progesterone were more marked in oophorectomized mice and were additive. MEIS1 expression was significantly lower in eutopic endometrium compared with normal endometrium in the midsecretory stage.

CONCLUSION(S)

MEIS1 is likely a key mediator between sex steroid and genes for uterine receptivity. Diminished endometrium MEIS1 expression may contribute to implantation failure in endometriosis.

Genome-wide DNA methylation analysis predicts an epigenetic switch for GATA factor expression in endometriosis

Endometriosis is a gynecological disease defined by the extrauterine growth of endometrial-like cells that cause chronic pain and infertility. The disease is limited to primates that exhibit spontaneous decidualization, and diseased cells are characterized by significant defects in the steroid-dependent genetic pathways that typify this process. Altered DNA methylation may underlie these defects, but few regions with differential methylation have been implicated in the disease. We mapped genome-wide differences in DNA methylation between healthy human endometrial and endometriotic stromal cells and correlated this with gene expression using an interaction analysis strategy. We identified 42,248 differentially methylated CpGs in endometriosis compared to healthy cells. These extensive differences were not unidirectional, but were focused intragenically and at sites distal to classic CpG islands where methylation status was typically negatively correlated with gene expression. Significant differences in methylation were mapped to 403 genes, which included a disproportionally large number of transcription factors. Furthermore, many of these genes are implicated in the pathology of endometriosis and decidualization. Our results tremendously improve the scope and resolution of differential methylation affecting the HOX gene clusters, nuclear receptor genes, and intriguingly the GATA family of transcription factors. Functional analysis of the GATA family revealed that GATA2 regulates key genes necessary for the hormone-driven differentiation of healthy stromal cells, but is hypermethylated and repressed in endometriotic cells. GATA6, which is hypomethylated and abundant in endometriotic cells, potently blocked hormone sensitivity, repressed GATA2, and induced markers of endometriosis when expressed in healthy endometrial cells. The unique epigenetic fingerprint in endometriosis suggests DNA methylation is an integral component of the disease, and identifies a novel role for the GATA family as key regulators of uterine physiology-aberrant DNA methylation in endometriotic cells correlates with a shift in GATA isoform expression that facilitates progesterone resistance and disease progression.

The role of progesterone and the progesterone receptor in human reproduction and cancer

Insufficient progesterone, effect possibly more on immune factors rather than adequate endometrial development, can be an easy remedial cause of infertility by simply supplementing the luteal phase with either vaginal or intramuscular or oral (dydrogesterone) progesterone. Progesterone will also help to reduce miscarriage rates when follicle maturing drugs are used for those with regular menses but follicular maturation defects, or women with recurrent miscarriages. One mechanism of action seems to be related to production of an immunomodulatory protein, the progesterone-induced blocking factor either in the cytoplasm or in the circulation. PIBF inhibits cytotoxicity of natural killer cells. Cancer cells may 'borrow' the same mechanism to escape NK cell immunosurveillance.