Oestrogen receptor-alpha gene polymorphism is associated with endometriosis, adenomyosis and leiomyomata

The clinical trial of alternative relugolix administration for uterine leiomyoma prior to surgically treatment: a study protocol for Non-Adverse Relugolix Administration (NARA) trial

BACKGROUND

Uterine leiomyomas are common for reproductive-aged women and affect women's quality of life due to heavy menstrual bleeding or dysmenorrhea. Leiomyomas grow according to estradiol exposure and decrease after post-menopause. In case serious symptoms are caused by leiomyomas, pharmacotherapy or surgical treatment is proposed. Prior to surgical treatment, pharmacotherapies aimed at the reduction of leiomyoma and uterine volume or improvement of anemia are introduced to conduct minimum invasive surgery (i.e., to reduce blood loss or surgical duration). Recently, relugolix (40 mg orally once daily) as a gonadotropin-releasing hormone (GnRH) receptor antagonist has proved its sufficient efficacy in suppressing estradiol levels without the transient estradiol flare-up compared with GnRH agonist. However, long-term administration should not be permitted liable to for climacteric disorder or osteoporosis, and evidence is lacking on the actual efficacy and extent of adverse effects of the every-other-day dosing regimen. This trial aimed to prove non-inferiority in volume reduction effect on leiomyoma and safety (i.e., reduction of adverse effects) by every-other-day administration after 2 months of everyday administration compared to daily administration throughout the duration.

METHODS

A minimization adaptive randomized control trial (RCT) will be conducted. Patients (over 20 years old) harboring leiomyoma who will be undergoing surgical treatment will be invited to participate. Patients who are enrolled in the intervention group will receive every-other-day administration for 16 weeks after 8 weeks of daily administration. Patients who are enrolled in the control group will receive daily throughout the 24 weeks. The primary outcome is the leiomyoma volume reduction, and the secondary endpoints are the reduction of uterine volume, the occurrence of the climacteric disorder, genital bleeding days, change rate of serum hormone or bone turnover markers, and bone mineral density after 24 weeks compared to before administration.

DISCUSSION

This study aims to prove both the non-inferiority in leiomyoma volume reduction and superiority in adverse effects occurrence reduction, which will provide a novel method to escape adverse effects while maintaining the effect of leiomyoma reduction.

TRIAL REGISTRATION

Japan Registry of Clinical Trials jRCTs051230078. Registered on 26 July 2023.

Concurrent Diagnosis of Adenomyosis and Congenital Uterine Anomalies: A Review

Background: Adenomyosis and congenital uterine anomalies (CUAs) can compromise reproductive potential and may coexist in the same patient, especially in cases of infertility. This review (CRD42022382850) aims to evaluate the published cases of concurrent adenomyosis and syndromic and nonsyndromic CUAs. Methods: A literature search for suitable articles published in the English language was performed using the following databases from inception to 30 November 2022: MEDLINE, EMBASE, Global Health, the Cochrane Library, Health Technology Assessment Database, and Web of Science. Articles including both CUAs and adenomyosis, with data about their potential relationship, were included. Results: The literature search retrieved 14 articles that met the purpose of this review and summarized the most recent findings regarding the concurrent diagnosis of adenomyosis and CUAs. Conclusions: Adenomyosis can be found in both syndromic and nonsyndromic CUAs, and may arise from several etiologies. The hypothesis that obstructions in CUAs increase uterine pressure and promote the development of adenomyosis remains to be further elucidated, and additional findings may also play a role. The patient's genetic, epigenetic, and hormonal patterns, as well as normal physiological processes, such as pregnancy, may influence the growth of adenomyosis.

The Effect of Estrogen-Related Genetic Variants on the Development of Uterine Leiomyoma: Meta-analysis

Uterine leiomyoma is the most common benign gynecological tumor in women of reproductive age. It has been diagnosed approximately in 5 to 69% of women and was symptomatic in 30% of them. The underlying pathobiology of uterine leiomyoma is not well understood yet, but it can be defined as an estrogen-dependent tumor. Thus, this meta-analysis aimed to investigate ESR1rs9340799 (XbaI, A351G), ESR1rs2234693 (Pvull, T397C), and COMT rs4680 (Val158Met) polymorphisms, which affect estrogen functioning and metabolism, in association with UL risk. According to PRISMA protocol, systematic searching of databases resulted 24 included studies. Pooled odds ratios (ORs) with 95% confidence intervals (CI) were used to evaluate associations of the three targeted polymorphisms with uterine leiomyoma risk in dominant model of inheritance. Meta-analysis included 4969 women diagnosed with uterine leiomyoma and 4934 controls. ESR1 (XbaI, A351G) polymorphism showed no significant association with uterine myeloma risk (OR = 1.19, 95% CI 0.98-1.45, P = 0.07). ESR1 (Pvull, T397C) was associated with a higher risk of uterine leiomyoma, but only in Asian (OR = 1.78, 95% CI 1.30-2.45, P = 0.0004) and COMT (Val158Met) according to our data is significantly associated with a lower risk of leiomyoma (OR = 0.83, 95% CI 0.71-0.97, P = 0.02). Our updated meta-analysis provided statistical evidence for the protective role of COMT (Val158Met) in association with the susceptibility to uterine leiomyoma and the possible role of ESR1 (Pvull, T397C) as a risk factor of this tumor.

Sex hormone-related polymorphisms in endometriosis and migraine: A narrative review

Some evidence indicates endometriosis and migraine have a common genetic predisposition in sex-hormone genes, which could have important implications for the treatment of these two heterogenous conditions. To date, the genes responsibility remains unknown. Based on the biological hypothesis that polymorphisms of genes involved in sex-hormone pathways may influence estrogen levels and phenotypes of both disorders, we did a literature search for candidate sex-hormone genes and genes involved in the metabolism of estradiol. The aim was to review the evidence for shared sex-hormone-related polymorphisms between endometriosis and migraine and provide an exhaustive overview of the current literature. We included case-control studies investigating associations between candidate sex-hormone-related genes and the disorders endometriosis and migraine, respectively. Results showed three overlapping sex-hormone-associated polymorphisms in estrogen receptor genes that are associated with both conditions. To confirm possible associations with other sex-hormone genes, larger studies are needed.

Association between single nucleotide polymorphism of the CYP19A1 and ESR2 genes and endometriosis

PURPOSE

Endometriosis is a frequent gynaecological condition, both in Poland and in the world. The development of this disease is supported by hormonal, immunological and environmental factors. During the recent years, a particular attention has been focused on the genetic polymorphisms which may be of particular significance for the increased incidence rates of endometriosis. According to literature data, Oestrogen Receptor 2 (ESR2) and Cytochrome P450 Family 19 Subfamily A Member 1 (CYP19A1) genes may be accounted to the potential risk factors of infertility associated with endometriosis. The reported research was aimed to evaluate the association between single nucleotide polymorphisms (SNPs) rs17179740 of ESR2 and rs2899470 of CYP19A1 genes and the incidence of endometriosis.

METHODS

The study material included blood specimens, collected from patients (n = 200) with endometriosis. Blood samples from age-matched, endometriosis-free women (n = 200) served as control. The High-Resolution Melter (HRM) technique was applied for polymorphism analysis.

RESULTS

Regarding rs2899470 polymorphism TT homozygotes was significantly more prevalent among the patients with endometriosis than in the controls (OR 2.19; p = 0.04). In case of rs17179740, GG homozygotes, as well as AG-AA genotypes, were significantly more prevalent among the endometriosis patients (OR 2.48, p = 0.04 and OR 2.36, p = 0.04, respectively).

CONCLUSION

Summing up, the investigated polymorphisms of ESR2 and CYP19A1 gene are associated with the observed incidence of endometriosis.

Genetic risk factors for endometriosis near estrogen receptor 1 and coexpression of genes in this region in endometrium

The etiology and pathogenesis of endometriosis are complex with both genetic and environmental factors contributing to disease risk. Genome-wide association studies (GWAS) have identified multiple signals in the estrogen receptor 1 (ESR1) region associated with endometriosis and other reproductive traits and diseases. In addition, candidate gene association studies identified signals in the ESR1 region associated with endometriosis risk suggesting genetic regulation of genes in this region may be important for reproductive health. This study aimed to investigate hormonal and genetic regulation of genes in the ESR1 region in human endometrium. Changes in serum oestradiol and progesterone concentrations and expression of hormone receptors ESR1 and progesterone receptor (PGR) were assessed in endometrial samples from 135 women collected at various stages of the menstrual cycle. Correlation between hormone concentrations, receptor expression and expression of genes in the ESR1 locus was investigated. The effect of endometriosis risk variants on expression of genes in the region was analyzed to identify gene targets. Hormone concentrations and receptor expression varied significantly across the menstrual cycle. Expression of genes in the ESR1 region correlated with progesterone concentration; however, they were more strongly correlated with expression of ESR1 and PGR suggesting coregulation of genes. There was no evidence that endometriosis risk variants directly regulated expression of genes in the region. Limited sample size and cellular heterogeneity in endometrial tissue may impact the ability to detect significant genetic effects on gene expression. Effects of these variants should be validated in a larger dataset and in relevant individual cell types.

The Genetic Background of Endometriosis: Can ESR2 and CYP19A1 Genes Be a Potential Risk Factor for Its Development?

Endometriosis is defined as the presence of endometrial foci, localized beyond their primary site, i.e., the uterine cavity. The etiology of this disease is rather complex. Its development is supported by hormonal, immunological, and environmental factors. During recent years, particular attention has been focused on the genetic mechanisms that may be of particular significance for the increased incidence rates of endometriosis. According to most recent studies, ESR2 and CYP19A1 genes may account for the potential risk factors of infertility associated with endometriosis. The paper presents a thorough review of the latest reports and data concerning the genetic background of the risk for endometriosis development.

Immunological changes associated with adenomyosis: a systematic review

BACKGROUND

Adenomyosis is a benign gynecological disorder associated with subfertility, pelvic pain and abnormal uterine bleeding that have significant consequences for the health and quality of life of women. Histologically, it is defined as the presence of ectopic endometrial islets within the myometrium. Its pathogenesis has not yet been elucidated and several pieces of the puzzle are still missing. One process involved in the development of adenomyosis is the increased capacity of some endometrial cells to infiltrate the myometrium. Moreover, the local and systemic immune systems are associated with the onset of the disease and with maintaining it. Numerous observations have highlighted the activation of immune cells and the release of immune soluble factors in adenomyosis. The contribution of immunity occurs in conjunction with hormonal aberrations and activation of the epithelial to mesenchymal transition (EMT) pathway, which promotes migration of endometrial cells. Here, we review current knowledge on the immunological changes in adenomyosis, with the aim of further elucidation of the pathogenesis of this disease.

OBJECTIVE AND RATIONALE

The objective was to systematically review the literature regarding the role of the immune system in development of adenomyosis in the inner and the outer myometrium, in humans.

SEARCH METHODS

A systematic review of published human studies was performed in MEDLINE, EMBASE and Cochrane Library databases from 1970 to February 2019 using the combination of Medical Subject Headings (MeSH): Adenomyosis AND ('Immune System' OR 'Gonadal Steroid Hormones'), and free-text terms for the following search terms (and their variants): Adenomyosis AND (immunity OR immune OR macrophage OR 'natural killer cell' OR lymphocyte* OR leucocyte* OR HLA OR inflammation OR 'sex steroid' OR 'epithelial to mesenchymal transition' OR 'EMT'). Studies in which no comparison was made with control patients, without adenomyosis (systemic sample and/or eutopic endometrium), were excluded.

OUTCOMES

A total of 42 articles were included in our systematic review. Changes in innate and adaptive immune cell numbers were described in the eutopic and/or ectopic endometrium of women with adenomyosis compared to disease-free counterparts. They mostly described an increase in lymphocyte and macrophage cell populations in adenomyosis eutopic endometrium compared to controls. These observations underscore the immune contributions to the disease pathogenesis. Thirty-one cytokines and other markers involved in immune pathways were studied in the included articles. Pro-inflammatory cytokines (interleukin (IL) 6, IL1β, interferon (IFN) α, tumor necrosis factor α, IFNγ) as well as anti-inflammatory or regulatory mediators (IL10, transforming growth factor β…) were found to be elevated in the eutopic endometrium and/or in the ectopic endometrium of the myometrium in women with adenomyosis compared to controls. Moreover, in women affected by adenomyosis, immunity was reported to be directly or indirectly linked to sex steroid hormone aberrations (notably changes in progesterone receptor in eutopic and ectopic endometrium) in three studies and to EMT in four studies.

WIDER IMPLICATIONS

The available literature clearly depicts immunological changes that are associated with adenomyosis. Both systemic and local immune changes have been described in women affected by adenomyosis, with the coexistence of changes in inflammatory as well as anti-inflammatory signals. It is likely that these immune changes, through an EMT mechanism, stimulate the migration of endometrial cells into the myometrium that, together with an endocrine imbalance, promote this inflammatory process. In light of the considerable impact of adenomyosis on women's health, a better understanding of the role played by the immune system in adenomyosis is likely to yield new research opportunities to better understand its pathogenesis.

Origin and Pathogenic Mechanisms of Uterine Adenomyosis: What Is Known So Far

Uterine adenomyosis is a benign disease, commonly encountered in reproductive-age women and responsible for chronic pelvic pain, abnormal uterine bleeding, and infertility. Although the exact origin and pathogenic mechanisms involved in adenomyosis still need to be elucidated, significant progress has been made over recent years. Ever since the theory of endometrium invaginating the myometrium via a traumatized interface was first proposed, numerous molecular mechanisms have been reported to participate in this process. At the same time, an alternative theory has suggested de novo development of adenomyotic lesions from metaplasia of Müllerian remnants or adult stem cells. Hence, our understanding of the pathogenesis of adenomyosis has been greatly enhanced and is anticipated to pave the way for development of an effective and safe treatment. The goal of this review is to analyze current knowledge on the origin and pathogenic mechanisms of adenomyosis, ranging from the most widely accepted theories to newly reported data.

Adenomyosis: Mechanisms and Pathogenesis

Adenomyosis is a common disorder of the uterus, and is associated with an enlarged uterus, heavy menstrual bleeding (HMB), pelvic pain, and infertility. It is characterized by endometrial epithelial cells and stromal fibroblasts abnormally found in the myometrium where they elicit hyperplasia and hypertrophy of surrounding smooth muscle cells. While both the mechanistic processes and the pathogenesis of adenomyosis are uncertain, several theories have been put forward addressing how this disease develops. These include intrinsic or induced (1) microtrauma of the endometrial-myometrial interface; (2) enhanced invasion of endometrium into myometrium; (3) metaplasia of stem cells in myometrium; (4) infiltration of endometrial cells in retrograde menstrual effluent into the uterine wall from the serosal side; (5) induction of adenomyotic lesions by aberrant local steroid and pituitary hormones; and (6) abnormal uterine development in response to genetic and epigenetic modifications. Dysmenorrhea, HMB, and infertility are likely results of inflammation, neurogenesis, angiogenesis, and contractile abnormalities in the endometrial and myometrial components. Elucidating mechanisms underlying the pathogenesis of adenomyosis raise possibilities to develop targeted therapies to ameliorate symptoms beyond the current agents that are largely ineffective. Herein, we address these possible etiologies and data that support underlying mechanisms.

Polymorphisms and endometriosis: a systematic review and meta-analyses

BACKGROUND

Endometriosis is an estrogen-dependent gynecological disorder that affects at least 10% of women of reproductive age. It may lead to infertility and non-specific symptoms such as chronic pelvic pain. Endometriosis screening and diagnosis are difficult and time-consuming. Late diagnosis (with a delay ranging from 3.3 to 10.7 years) is a major problem and may contribute to disease progression and a worse response to treatment once initiated. Efficient screening tests might reduce this diagnostic delay. As endometriosis is presumed to be a complex disease with several genetic and non-genetic pathogenic factors, many researchers have sought to identify polymorphisms that predispose to this condition.

OBJECTIVE AND RATIONALE

We performed a systematic review and meta-analysis of the most regularly reported polymorphisms in order to identify those that might predispose to endometriosis and might thus be of value in screening.

SEARCH METHODS

The MEDLINE database was searched for English-language publications on DNA polymorphisms in endometriosis, with no date restriction. The PubTator text mining tool was used to extract gene names from the selected publications' abstracts. We only selected polymorphisms reported by at least three studies, having applied strict inclusion and exclusion criteria to their control populations. No stratification based on ethnicity was performed. All steps were carried out according to PRISMA guidelines.

OUTCOMES

The initial selection of 395 publications cited 242 different genes. Sixty-two genes (corresponding to 265 different polymorphisms) were cited at least in three publications. After the application of our other selection criteria (an original case-control study of endometriosis, a reported association between endometriosis and at least one polymorphism, data on women of reproductive age and a diagnosis of endometriosis in the cases established by surgery and/or MRI and confirmed by histology), 28 polymorphisms were eligible for meta-analysis. Only five of the 28 polymorphisms were found to be significantly associated with endometriosis: interferon gamma (IFNG) (CA) repeat, glutathione S-transferase mu 1 (GSTM1) null genotype, glutathione S-transferase pi 1 (GSTP1) rs1695 and wingless-type MMTV integration site family member 4 (WNT4) rs16826658 and rs2235529. Six others showed a significant trend towards an association: progesterone receptor (PGR) PROGINS, interCellular adhesion molecule 1 (ICAM1) rs1799969, aryl-hydrocarbon receptor repressor (AHRR) rs2292596, cytochrome family 17 subfamily A polypeptide 1 (CYP17A1) rs743572, CYP2C19 rs4244285 and peroxisome proliferator-activated receptor gamma (PPARG) rs1801282), and 12 showed a significant trend towards the lack of an association: tumor necrosis factor (TNF) rs1799964, interleukin 6 (IL6) rs1800796, transforming growth factor beta 1 (TGFB1) rs1800469, estrogen receptor 1 (ESR1) rs2234693, PGR rs10895068, FSH receptor (FSHR) rs6166, ICAM1 rs5498, CYP1A1 rs4646903, CYP19A1 rs10046, tumor protein 53 (TP53) rs1042522, X-ray repair complementing defective repair in Chinese hamster cells 1 (XRCC1) rs25487 and serpin peptidase inhibitor clade E member 1 (SERPINE1) rs1799889; however, for the 18 polymorphisms identified in the latter two groups, further studies of the potential association with the endometriosis risk are needed. The remaining five of the 28 polymorphisms were not associated with endometriosis: glutathione S-transferase theta 1 (GSTT1) null genotype, vascular endothelial growth factor alpha (VEGFA) rs699947, rs833061, rs2010963 and rs3025039.

WIDER IMPLICATIONS

By carefully taking account of how the control populations were defined, we identified polymorphisms that might be candidates for use in endometriosis screening and polymorphisms not associated with endometriosis. This might constitute the first step towards identifying polymorphism combinations that predispose to endometriosis (IFNG (CA) repeat, GSTM1 null genotype, GSTP1 rs1695, WNT4 rs16826658 and WNT4 rs2235529) in a large cohort of patients with well-defined inclusion criteria. In turn, these results might improve the diagnosis of endometriosis in primary care. Lastly, our present findings may enable a better understanding of endometriosis and improve the management of patients with this disease.

Oestrogen receptor alpha PvuII polymorphism and uterine fibroid incidence in Caucasian women

Introduction

Uterine fibroids (UFs) are benign, monoclonal tumours of the female genital tract that originate from the myometrium. They may be diagnosed in as many as 80% of women depending on the selected population. UFs depend mostly on steroid hormones. Elevated levels of oestrogens and progesterone are believed to be among the most important factors inducing their formation and growth. These facts suggest that oestrogen (ESR) and progesterone receptors are crucial in UF pathophysiology as well. Previous studies have shown that, in some populations, polymorphisms in ESR genes (e.g. PvuII) constitute an important risk factor for UFs.

Material and methods

The aim of our study was to investigate whether ESRα PvuII polymorphism is associated with an increased risk of UFs in Caucasian women of Polish origin. A total of 197 patients (114 UF-positive and 83 controls) were included in this retrospective cohort study. ESRα gene polymorphism PvuII (rs2234693) was assayed with PCR and restriction fragment length polymorphism (RFLP).

Results

Our study found no significant difference in the occurrence of ESR PvuII polymorphism between women with UFs and UF-free controls in the selected population.

Conclusions

Our results did not indicate a significant association between ESRα gene PvuII polymorphism and the risk of UFs in Caucasian women of Polish origin. More studies and comparisons between races are necessary to clarify the role of ESRα in the development and progression of UFs.

Recent Advances in Molecular Genetics of Endometriosis

Endometriosis (MIM 131200) is a prevalent and complex gynecological disease polygenically inherited with multifactorial pathogenesis. It is increasingly recognized as a major women's health issue. Endometriosis is characterized by the presence of endometrial-like tissue in sites outside the uterus, mainly the pelvic peritoneum, ovaries and rectovaginal septum causing severe dysmenorrhoea, dyspareunia, chronic pelvic pain and subfertility. Recent advances in molecular technologies have provided many evidences about the underlying biological events that are likely to be involved in the development of endometriosis. Different chromosomal regions, genes and other molecules, such as microRNAs, have been identified as potentially involved in endometriosis pathogenesis. Moreover, genome-wide analyses of endometriosis have showed novel molecular signatures or individual genes that had not been previously associated with the disease. The goal of these studies is to provide information that might, in turn, lead to new therapies. In this review, some previous studies were updated supporting the polygenic/multifactorial inheritance and the association with malignant neoplasias. We have also emphasized the importance of identifying the causative genes and determining novel diagnostic and predictive biomarkers.

Evaluation of Risk Factors Associated with Endometriosis in Infertile Women

BACKGROUND

Endometriosis affects women's physical and mental wellbeing. Symptoms include dyspareunia, dysmenorrhea, pelvic pain, and infertility. The purpose of this study is to assess the correlation between some relevant factors and symptoms and risk of an endometriosis diagnosis in infertile women.

MATERIALS AND METHODS

A retrospective study of 1282 surgical patients in an infertility Institute, Iran between 2011 and 2013 were evaluated by laparoscopy. Of these, there were 341 infertile women with endometriosis (cases) and 332 infertile women with a normal pelvis (comparison group). Chi-square and t tests were used to compare these two groups. Logistic regression was done to build a prediction model for an endometriosis diagnosis.

RESULTS

Gravidity [odds ratio (OR): 0.8, confidence interval (CI): 0.6-0.9, P=0.01], parity (OR: 0.7, CI: 0.6-0.9, P=0.01), family history of endometriosis (OR: 4.9, CI: 2.1-11.3, P<0.001), history of galactorrhea (OR: 2.3, CI: 1.5-3.5, P=0.01), history of pelvic surgery (OR: 1.9, CI: 1.3-2.7, P<0.001), and shorter menstrual cycle length (OR: 0.9, CI: 0.9-0.9, P=0.04) were associated with endometriosis. Duration of natural menstruation and age of menarche were not correlated with subsequent risk of endometriosis (P>0.05). Fatigue, diarrhea, constipation, dysmenorrhea, dyspareunia, pelvic pain and premenstrual spotting were more significant among late-stage endometriosis patients than in those with early-stage endometriosis and more prevalent among patients with endometriosis than that of the comparison group. In the logistic regression model, gravidity, family history of endometriosis, history of galactorrhea, history of pelvic surgery, dysmenorrhoea, pelvic pain, dysparaunia, premenstrual spotting, fatigue, and diarrhea were significantly associated with endometriosis. However, the number of pregnancies was negatively related to endometriosis.

CONCLUSION

Endometriosis is a considerable public health issue because it affects many women and is associated with the significant morbidity. In this study, we built a prediction model which can be used to predict the risk of endometriosis in infertile women.

Association of endometriosis and breast cancer: mini review of the literature

BACKGROUND

Endometriosis is a common, estrogen-dependent, gynecological disease, which is defined as the presence of endometrial tissue outside the uterine cavity. Current data have associated endometriosis with specific malignancies, including ovarian and breast cancer.

PURPOSE

The purpose of our study is to summarize and present published literature providing evidence regarding the possible relationship between endometriosis and breast cancer.

METHODS

Pubmed and Scopus databases were searched systematically for studies that sought to identify a potential association of endometriosis and breast cancer. 15 relevant articles were retrieved and included in the present review.

RESULTS

A small number of observational studies have shown a correlation of endometriosis and breast cancer. Other studies found that the risk of breast cancer increases with age. The scenario of an early interruption of the inflammatory process, derived from endometriosis, by oophorectomy and a possible consequent decrease in the risk of breast cancer has also been proposed. The hypothesis that both conditions could be related through common mutations on BRAC1 and BRAC2 genes has also been investigated.

CONCLUSION

The available published evidence is inconclusive. Further studies are needed to evaluate the association of endometriosis and breast cancer and the possible pathogenetic pathways that relate the two disorders.

Risk for estrogen-dependent diseases in relation to phthalate exposure and polymorphisms of CYP17A1 and estrogen receptor genes

Evidence has shown that polymorphisms of various genes known to be involved in estrogen biosynthesis and function are associated with estrogen-dependent diseases (EDDs). These genes include CYP17A1, estrogen receptor 1 (ESR1), and 2 (ESR2). Phthalates are considered estrogenic endocrine disruptors, and recent research has suggested that they may act as a risk factor for EDDs. However, extremely few studies have assessed the effects of gene-environment interaction on these diseases. We recruited 44 patients with endometriosis or adenomyosis, 36 patients with leiomyoma, and 69 healthy controls from a medical center in Taiwan between 2005 and 2007. Urine samples were collected and analyzed for seven phthalate metabolites using liquid chromatography tandem mass spectrometry. Peripheral lymphocytes were used for DNA extraction to determine the genotype of CYP17A1, ESR1, and ESR2. Compared to controls, patients with leiomyoma had significantly higher levels of total urinary mono-ethylhexyl phthalate (ΣMEHP) (52.1 vs. 29.6 μg/g creatinine, p = 0.040), mono-n-butyl phthalate (MnBP) (75.4 vs. 51.3 μg/g creatinine, p = 0.019), and monoethyl phthalate (MEP) (103.7 vs. 59.3 μg/g creatinine, p = 0.031). In contrast, patients with endometriosis or adenomyosis showed a marginally increased level of urinary MEHP only. Subjects who were homozygous for both the ESR1 C allele (rs2234693) and CYP17A1 C allele (rs743572) showed a significantly increased risk for leiomyoma (OR = 19.8; 95 % CI, 1.70; 231.5; p = 0.017) relative to subjects with other genotypes of ESR1 and CYP17A1. These results were obtained after adjusting for age, cigarette smoking, MEHP level, GSTM1 genotype and other covariates. Our results suggested that both CYP17A1 and ESR1 polymorphisms may modulate the effects of phthalate exposure on the development of leiomyoma.

Potential mechanisms of an antiadenomyosis chinese herbal formula shaoyao-gancao decoction in primary cell culture model

Background. Shaoyao-Gancao Decoction (SGD), a well-known traditional Chinese medicine prescription, has been widely used to treat adenomyosis, dysmenorrhea, abdominal pain, and inflammation in Asia. However, the mechanism underlying the effectiveness of SGD in the treatment of adenomyosis still remains elusive. The present study aimed to investigate the bioactivity of SGD and its underlying molecular mechanisms using cultured human adenomyosis-derived cells. Methods. Human adenomyosis-derived cells were treated with SGD and its major constituents (paeoniflorin and liquiritin) in vitro. Effects of SGD, paeoniflorin, and liquiritin on cell proliferation and apoptosis were examined by MTT assay and flow cytometry analyses. The effects of SGD, paeoniflorin, and liquiritin on the production of PGE₂ and PGF_2α were assayed using ELISA. ER-α and OTR mRNA expression levels were also evaluated by real-time qRT-PCR. Results. SGD, paeoniflorin, and liquiritin inhibited proliferation and induced apoptosis of human adenomyosis-derived cells in a dose-dependent manner. SGD and paeoniflorin significantly reduced the PGE₂ and PGF_2α production. Furthermore, they remarkably decreased the mRNA levels of ER-α and OTR. Conclusions. The results of this study provide possible mechanisms for the bioactivity of SGD for treating adenomyosis and contribute to the ethnopharmacological knowledge about this prescription.

Screening of a panel of steroid-related genes showed polymorphisms of aromatase genes confer susceptibility to advanced stage endometriosis in the Taiwanese Han population

OBJECTIVE

To establish a multilocus model for studying the effect of steroid-related genes on advanced stage endometriosis.

MATERIALS AND METHODS

A total of 121 patients with advanced stage endometriosis and 171 control women were included. Eighteen single-nucleotide polymorphisms (SNPs) from nine genes (HSD17B1, HSD17B2, HSD17B5, HSD17B6, CYP17, CYP19, ERα, ERβ, and PGR) were genotyped using the TaqMan assays. Logistic regression models were used to evaluate the genetic effects, with adjustment for other covariates.

RESULTS

Only the presence of the mutant CYP19 (aromatase gene) was associated with a significantly increased risk of endometriosis after adjusting for age, BMI, and parity (p = 0.002, OR = 2.69; 95% CI = 1.44-5.02). No association was ascertained between the other investigated SNPs and endometriosis.

CONCLUSION

Polymorphisms of the aromatase gene confer susceptibility to advanced stage endometriosis in the Taiwanese Han population.

ESR1 rs9340799 is associated with endometriosis-related infertility and in vitro fertilization failure

Estrogen receptor alpha has a central role in human fertility by regulating estrogen action in all human reproductive tissues. Leukemia inhibitory factor (LIF) expression, a cytokine critical for blastocyst implantation, is mediated by estrogen signaling, so we hypothesized that ESR1 gene polymorphisms might be candidate risk markers for endometriosis-related infertility and in vitro fertilization (IVF) failure. We included 98 infertile women with endometriosis, 115 infertile women with at least one IVF failure and also 134 fertile women as controls. TaqMan SNP assays were used for genotyping LIF (rs929271), MDM2 (rs2279744), MDM4 (rs1563828), USP7 (rs1529916), and ESR1 (rs9340799 and rs2234693) polymorphisms. The SNP ESR1 rs9340799 was associated with endometriosis-related infertility (P < 0.001) and also with IVF failure (P = 0.018). After controlling for age, infertile women with ESR1 rs9340799 GG genotype presented 4-fold increased risk of endometriosis (OR 4.67, 95% CI 1.84–11.83, P = 0.001) and 3-fold increased risk of IVF failure (OR 3.33, 95% CI 1.38–8.03, P = 0.007). Our results demonstrate an association between ESR1 rs9340799 polymorphism and infertile women with endometriosis and also with women who were submitted to IVF procedures and had no blastocyst implantation.

Genetic Polymorphisms Associated with Endometriosis in Pakistani Women

Background

Endometriosis is a common disease that causes pain and infertility. The heritable predisposition toward endometriosis motivates an interest to identify the genes and genomic variants involved in the pathogenesis of endometriosis. Both genetic and environmental factors contribute to this disease. Here we investigated in Pakistani women the association of endometriosis and single nucleotide polymorphisms (SNP) in genes previously identified in the development of this disease.

Methods

DNA samples from 52 genetically unrelated endometriosis subjects with endometriosis and 52 randomly selected controls were analyzed by direct sequencing to determine polymorphisms in four genes. These included estrogen receptor alpha (ESR1) (rs2234693 C/T, rs9340799 G/A SNP), estrogen receptor beta (ESR2) (rs4986938 G/A SNP), progesterone receptor (PGR) (rs1042838 G/T, rs10895068 G/A SNPs) and interleukin 10 (IL10) (rs1800871 C/T, rs1800872 C/A and rs1800896 G/A SNPs).

Results

The allele A at −592, T at −819 and G at −1080 of IL10 and all of the SNPs studied at ESR2 and PGR show strong, statistically significant associations with the disease. However, the genetic variation at ESR1 was distributed similarly among cases and control groups.

Conclusion

These findings suggest that the functional promoter polymorphism of the IL10 gene, identified by the “ATG” genotype, may contribute to the risk of endometriosis. Genetic variants of ESR2 and PGR gene may also be a risk factor as well as influence the fertility status of patients with endometriosis.

Genetic polymorphims of estrogen receptor alpha -397 PvuII (T>C) and -351 XbaI (A>G) in a portuguese population: prevalence and relation with breast cancer susceptibility

Estrogen receptor alpha (ERα), that mediates the biologic effects of estrogen in estrogen-sensitive tissues like breast, is genetically polymorphic. To evaluate the association between -397 PvuII (T>C) and -351 XbaI (A>G) restriction fragment length polymorphisms (RFLPs) in intron 1 of ERα gene and susceptibility of breast cancer, we undertook a case-control study in BRCA1 185delAG and 5382insC/BRCA2 6174delT negative Portuguese women. The study population consisted of 107 patients with histological diagnosis of breast cancer and 121 women with no history of breast cancer. Genomic DNA was extracted from blood samples and genotyping analyses were performed by PCR-RFLP. XbaI polymorphism was associated with a significant reduced risk of breast cancer for carriers of the x allele in homozygozity (OR 0.178; 95% CI 0.070-0.456; P<0.001) or heterozigozity (OR 0.223; 95% CI 0.089-0.561; P=0.001). The PvuII polymorphism was associated with a non-significantly reduced risk. The combined analysis of PvuII and XbaI polymorphisms revealed none synergistic effect of the two genotypes, except for simultaneous carriers of pp and xx genotypes, that have a reduced risk of breast cancer (OR 0.226; 95% CI 0.049-1.035; P=0.044). The combination of PvuII and XbaI genotypes into haplotypes showed that carriers of two copies of the px (ppxx) haplotype had a reduced risk of breast cancer (OR 0.405; 95% CI 0.194-0.843; P=0.014), compared with PX (PPXX+PPXx+PpXX+PpXx) haplotypes. PvuII and XbaI polymorphisms were in linkage disequilibrium both in cases (D=0.044, r2=0.049, X2=5.216, P=0.022) and controls (D=0.090, r2=0.139, X2=16.819, P<0.001), but not in the entire sample population analyzed as a whole (D=0.087, r2=0.0076, X2=1.733, P=0.188). In conclusion, in this case-control study we found that ERα gene XbaI polymorphism may modify individual susceptibility for breast cancer in this population.

Is fibroid heterogeneity a significant issue for clinicians and researchers?

The clinical and scientific literature overwhelmingly deals with fibroids as a single entity or disease. This convenient assumption of homogeneity may be an important oversight given that substantial evidence exists for heterogeneity between fibroids at many levels. Failure to recognize and accommodate fibroid heterogeneity can have significant ramifications for both clinical treatment decisions and research protocol design. The aim of this article is to review the current knowledge of fibroid heterogeneity and to identify key areas where fibroid heterogeneity should be taken into consideration both clinically and when designing research protocols. Uterine leiomyomata display significant and well-documented heterogeneity in symptoms, diagnostic imaging appearance, pathology, genetic background and therapeutic requirements. Additional research is needed to better understand fibroid heterogeneity as it relates to pathogenesis, molecular targets for potential new therapies, patient symptoms and, ultimately, treatment. To this list should also be added heterogeneity of genetics, lifestyle and individual clinical characteristics of the fibroid. Increasingly, an understanding of uterine leiomyoma heterogeneity will be of importance for clinicians who see patients with this common and costly disease.

Association of estrogen receptor alpha (ERα) gene polymorphisms with endometrial thickness and lipid profile in women with breast cancer treated with aromatase inhibitors

Aromatase inhibitors (AIs) provide an alternative to tamoxifen as an adjuvant therapy for post-menopausal, hormone-receptor positive breast cancer patients. The aim of the present study was to evaluate the effect of PvuII and XbaI polymorphisms of the ERα gene at ΑΙs treatment's adverse effects in post-menopausal women with breast cancer. The study included 87 post-menopausal women with ER-positive breast cancer treated with AIs and 80 healthy controls. The overall presence of ERα polymorphisms in all women with breast cancer was not different from the healthy controls. Endometrial thickness under AIs treatment was reduced from (mean value ± SD) 6,404 ± 2,901 mm to 3,666 ± 1,4656 mm. Moreover, the AA XbaI genotype was associated with greater reduction in endometrial thickness during therapy with AIs (p = 0.005). The presence of the CC PvuII and the AA XbaI genotypes were associated with elevated LDL levels and elevated triglycerides. In conclusion, the results of the present study showed that the genotype of women with breast cancer under AIs treatment might influence treatment's adverse effects, as, the presence of the CC PvuII and the AA XbaI genotypes of the ERα were associated with elevated LDL and triglycerides serum levels, while the AA XbaI genotype was associated with a greater reduction in endometrial thickness.

Estrogen receptor-alpha gene PvuII (T/C) and XbaI (A/G) polymorphisms and endometriosis risk: a meta-analysis

Estrogen receptor-alpha (ER-α) polymorphisms have been hypothesized to be associated with the risk of endometriosis (EMT) development by many epidemiological studies, however, the available results were conflicting. To derive a more precise estimation of association between the ER-α PvuII (T/C) and XbaI (A/G) polymorphisms and risk of EMT, we performed a meta-analysis. Summary odds ratios (ORs) and 95% confidence intervals (95% CIs) for ER-α polymorphisms and EMT were calculated in a fixed-effects model and a random-effects model when appropriate. This meta-analysis included 20 case-control studies with 1752 cases and 1742 controls for PvuII polymorphism and 15 case-control studies with 1349 cases and 1411 controls for XbaI polymorphism. For PvuII T/C polymorphism, no obvious associations were found for all genetic models when all studies were pooled into the meta-analysis. In the subgroup analyses by ethnicity, country, HWE in controls and study sample size, a significantly increased risk was observed among Caucasians (recessive model, OR=2.56, 95% CI=1.06-6.16) and among studies without the HWE (recessive model, OR=1.85, 95% CI=1.20-2.84). For XbaI A/G polymorphism, also no obvious associations were found for all genetic models. In the subgroup analyses by ethnicity, country, HWE in controls and study sample size, still no obvious associations were found. No publication bias was found in the present study. This meta-analysis suggests that ER-α gene PvuII (T/C) and XbaI (A/G) polymorphisms may not be associated with EMT risk, while the observed increase in risk of EMT may be due to small-study bias.

Cyclooxygenase-2 ( COX -2) gene-765G/C polymorphism and advanced-stage endometriosis in Korean women

PROBLEM

We investigated the association of COX -2 gene-765G/C polymorphism and risk of advanced-stage endometriosis in Korean women.

METHOD OF STUDY

This study consisted of 268 women with advanced-stage endometriosis and 242 control women without endometriosis in Korea. Subjects were genotyped for the -765G/C polymorphism of the COX -2 gene by RFLP-PCR analysis.

RESULTS

There were significant differences in the genotype distributions of the -765G/C polymorphism between patients with advanced-stage endometriosis and control subjects. The C allele for -765G/C was associated with significantly lower risk of advanced-stage endometriosis (OR, 0.14; 95% CI, 0.06-0.30).

CONCLUSIONS

We have demonstrated a significant genetic association between the -765G/C polymorphism and advanced-stage endometriosis in Korean women. The -765C allele may be protective against the development of the disease in Korean women.

Pathogenesis of endometriosis: the role of genetics, inflammation and oxidative stress

INTRODUCTION

Endometriosis is defined as the presence of endometrial tissue outside the uterine cavity.

MATERIALS AND METHODS

The etiology of this multifactorial disease is still unresolved and an increasing number of studies suggest that genetic, hormonal, environmental, immunological and oxidative factors may all play an important role in the pathogenesis of this disorder.

CONCLUSIONS

In this literature review, inflammatory activity, oxidative stress as well as genetic abnormalities and mutations have been studied in an effort to identify factors predisposing to endometriosis.

Failure to detect significant association between estrogen receptor-alpha gene polymorphisms and endometriosis in Japanese women

OBJECTIVES

The aim of the study was to test whether estrogen receptor 1 (ESR1) gene polymorphisms are correlated with the risk of the development of endometriosis in Japanese women, as a preliminary study.

METHODS

To compare allelic frequencies and genotype distributions, a case-control study of 100 affected women and 143 women with no evidence of disease was performed using 10 microsatellite repeat markers and 66 single-nucleotide polymorphisms (SNPs) in the ESR1 gene region.

RESULTS

Although our results might be insufficient to detect genetic susceptibility, owing to the small sample size and low genetic power, statistical analysis of the differences in allelic frequency between the cases and controls at each microsatellite locus demonstrated that no microsatellite locus in the ESR1 gene displayed a significant association with the disease when multiple testing was taken into account. Also, there were no statistically significant differences in the SNP allele frequencies and genotypes between the cases and controls when multiple testing was taken into account.

CONCLUSION

The findings in our pilot study suggest that ESR1 polymorphisms do not contribute to endometriosis susceptibility.

Enhanced transcription of estrogen receptor α and mitochondrial cytochrome b genes in uterine leiomyomas

The relative expression levels of estrogen receptor α (ERα) and mitochondrial cytochrome b (MTCYB) transcripts and their association with ERα, -397T > C gene polymorphism was determined in premenopausal uterine leiomyomas and myometrium tissues to gain an insight into the role of ER-mediated action of estrogen on mitochondrial gene transcription. Both ERα and MTCYB transcripts were overexpressed in leiomyomas compared with myometrium tissues with 9.18 ± 0.79 folds and 5.24 ± 0.48 folds, respectively. ERα demonstrated ≥1.7 folds overexpression expressed over MTCYB (p < 0.001). Genotype correlation with transcript expression revealed that leiomyomas with CC genotype had significantly increased levels of ERα with 11.9 ± 1.02 folds as compared with 6.46 ± 0.56 folds seen in CT and TT genotypes together (p < 0.001). Interestingly, MTCYB transcript levels were also >1.9 folds overexpressed in leiomyomas with the CC genotype as compared with leiomyomas with other genotypes (p < 0.01).Significant elevation of ERα and MTCYB transcript levels in premenopausal leiomyomas and its association with ERα, -397 CC genotype suggests the mitochondrial-mediated role of estrogen as the promoter of leiomyoma tumorigenesis.

Association of estrogen receptor α gene PvuII and XbaI polymorphisms with non-small cell lung cancer

Single nucleotide polymorphisms (SNPs) of the estrogen receptor (ER)-α have been found to be associated with various diseases at significantly different frequencies. However, whether any relationship exists between ER-α polymorphisms and lung cancer remains to be determined. In this study, 84 non-smoking, female, non-small cell lung cancer patients with various stages of disease and 234 cancer-free reference controls were enrolled to examine the association of ER-α polymorphisms in lung cancer. Two restriction SNP sites, PvuII and XbaI, in the first intron of the ER-α gene were genotyped by polymerase chain reaction-restriction fragment length polymorphism. The frequencies of the PvuII-XbaI haplotypes and genotypes in a Taiwanese population were revealed for the first time. Although the genotypic frequencies of two polymorphic sites of ER- α were in linkage disequilibrium for the lung cancer group (χ(2)=50.013, d.f.=4) and reference controls (χ(2)=60.797, d.f.=4); and 7 and 8 combined genotypes were present, respectively, the distribution and the major genotypes are different in the two groups (p<0.0001). The p-values for PvuII and XbaI genotypes were significantly different between the lung cancer and reference controls. The PP genotype presence was found to be significantly lower in the lung cancer group (P=0.005), whereas presence of the xx genotype was significantly higher (P=0.042). These findings suggested that the PP genotype had a lower risk of lung cancer; whereas the xx genotype had a higher risk. In comparison with other studies conducted in various populations, it is of note that the pX haplotype frequency of this study was higher than that of other studies, whereas the px haplotype was lower. Moreover, the Xx genotypic frequency of XbaI polymorphisms in the ER-α gene of the reference control group was found to be extremely high, whereas the xx genotypic frequency was extremely low. In conclusion, PvuII-XbaI polymorphisms of the ER-α gene were found to be associated with the risk, but not cancer severity, of non-small cell lung cancer in a Taiwanese population.

Estrogen receptor 1, glutathione S-transferase P1, glutathione S-transferase M1, and glutathione S-transferase T1 genes with dysmenorrhea in Korean female adolescents

BACKGROUND

Dysmenorrhea is the most common gynecologic complaint among adolescent females. We investigated the association between genetic polymorphisms and dysmenorrhea.

METHODS

A total of 202 postmenarcheal Korean female adolescents 16-17 yr old participated in this study. Genotyping for glutathione S-transferase mu 1 (GSTM1), glutathione S-transferase theta 1 (GSTT1), glutathione S-transferase pi 1 (GSTP1), and estrogen receptor 1 (ESR1) was performed using PCR-based methods.

RESULTS

The PP+Pp genotype of the ESR1 gene was more frequent than pp genotypes in subjects with dysmenorrhea than in subjects without dysmenorrhea (odds ratio=2.440; 95% confidence interval, 1.036-5.753; P=0.040) using an unadjusted univariate logistic regression analysis. The relationship between dysmenorrhea and ESR1 gene polymorphisms remained significant after adjustment for premenstrual syndrome, years elapsed after menarche, and family history of dysmenorrhea. No significant difference was observed between subjects with dysmenorrhea and subjects without dysmenorrhea for polymorphisms of GSTM1, GSTT1, and GSTP1 genes.

CONCLUSIONS

Our results suggest that ESR1 gene polymorphisms may be associated with dysmenorrhea.

Advances in the genetics of endometriosis

Endometriosis is a gynecological disease characterized by implantation of endometrial tissue outside of the uterus. Early familial aggregation and twin studies noted a higher risk of endometriosis among relatives. Studies on the roles of the environment, genetics and aberrant regulation in the endometrium and endometriotic lesions of women with endometriosis suggest that endometriosis arises from the interplay between genetic variants and environmental factors. Elucidating the hereditary component has proven difficult because multiple genes seem to produce a susceptibility to developing endometriosis. Molecular techniques, including linkage and genome-wide analysis, have identified candidate genes located near known loci related to development and regulation of the female reproductive tract. As new candidate genes are discovered and hereditary pathways identified using technologies such as genome-wide analysis, the possibility of prevention and treatment becomes more tangible for millions of women affected by endometriosis. Here, we discuss the advances of genetic research in endometriosis and describe technologies that have contributed to the current understanding of the genetic variability in endometriosis, variability that includes regulatory polymorphisms in key genes.

CYP17 and CYP2C19 gene polymorphisms in patients with endometriosis

Endometriosis seems to be the result of a complex interaction between environmental factors and various genes. In this regard, the cytochrome subfamily 17 (CYP17) may play an important role by altering the biosynthesis of sex steroids. CYP2C19 is also an important member of the cytochrome P450 (CYP) family, and related mutations may result in an inability to fully metabolize environmental chemicals and cytokines, leading to several diseases. This study sought to determine whether there is a relationship between endometriosis and CYP17 T>C, CYP2C19 *2 and CYP2C19 *3 polymorphisms. When samples from 46 patients with endometriosis and 39 healthy controls were analysed, A2A2 type mutation of the CYP17 gene was observed to be more frequent in patients with endometriosis (34.8 versus 7.7%, P = 0.003). No association was found between the severity of endometriosis and CYP2C19 *2 or CYP2C19 *3 polymorphisms of the CYP2C19 gene. These results suggest that mutations related with sex steroid metabolism seem to have an important role in endometriosis. However, the relation between detoxification ability and endometriosis should be examined in further studies with larger sample sizes.

Estrogen receptor-alpha polymorphisms and predisposition to TMJ disorder

Temporomandibular joint disorders (TMJD) affect women with greater frequency than men, and sex hormones may contribute to this female predominance. Therefore, this study investigated whether estrogen receptor-alpha (XbaI/PvuII) single nucleotide polymorphisms (SNPs) are associated with TMJD in women. DNA was obtained from 200 women with TMJD (100 with chronic pain and 100 with signs of TMJD but no pain) diagnosed according to the Research Diagnostic Criteria for Temporomandibular Disorder (RDC/TMD) and 100 control women without TMJD. Restriction fragment length polymorphisms of polymerase chain reaction products were used to analyze XbaI and PvuII SNPs in DNA fragments. A model directly characterizing specific DNA sequence variants based on the risk haplotypic structure implemented with the EM algorithm was used to analyze the data. The [GC] haplotype of the XbaI locus was significantly more prevalent in both TMJD groups when compared with the control group (P = .0012). Specifically, the [GC] haplotype was more prevalent within the painful TMJD group versus the control group (OR = 3.203, 95% CI = 1.633, 6.284) and in the TMJD no pain versus the control group (OR = 2.51, 95% CI = 1.267, 4.97). In conclusion, the presence of [GC] haplotype in the XbaI locus may increase the susceptibility of women to develop TMJD.

PERSPECTIVE

This study suggests that a polymorphism in the estrogen receptor may increase the risk of women developing temporomandibular joint disorder. This finding may elucidate the interindividual differences in the contribution of estrogen to TMJD, the genetic influences on TMJD predisposition, and may serve as the basis for future treatment tailoring, which could enhance outcomes for these patients.

Hormone therapy for endometriosis and surgical menopause

BACKGROUND

Endometriosis is characterized by the presence of ectopic endometrial tissue that might lead to many distressing and debilitating symptoms. Despite available studies supporting standard hormone therapy for women with endometriosis and post-surgical menopause, there is still a concern that estrogens may induce a recurrence of the disease and its symptoms.

OBJECTIVES

This review aimed to look at pain and disease recurrence in women with endometriosis who used hormone therapy for post-surgical menopause.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group Specialized Register (March 2008), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 3), MEDLINE (1966 to March 2008), EMBASE (1980 to March 2008), and references lists of articles. Relevant journals and conference proceedings were handsearched.

SELECTION CRITERIA

Randomized controlled trials studying hormone therapy for women with endometriosis in post-surgical menopause.

DATA COLLECTION AND ANALYSIS

Review authors assessed the eligibility of trials and their quality.

MAIN RESULTS

Two studies fulfilled our inclusion criteria. One trial compared the nonstop transdermal application of 17beta-estradiol (0.05 mg/day) combined with cyclic medroxy progesterone acetate (10 mg per day) for 12 days per month in women with a conserved uterus with nonstop tibolone (2.5 mg/day). The second trial used sequential administration of estrogens and progesterone with two 22 cm(2) patches applied weekly to produce a controlled release of 0.05 mg/day. Micronized progesterone was administered orally (200 mg/day) for 14 days with a 16-day interval free of treatment. Pain and dyspareunia The first trial reported recurrence of pain in the estrogen and progesterone arm in 4/10 of women compared with 1/11 in the tibilone arm. In the latter, 4/115 women reported recurrence of pain in the treatment group compared with 0/57 patients in the no-treatment arm. Neither finding was statistically different.Confirmed recurrence or exacerbation of endometriosis This outcome was not reported in the first trial. The second found that 2/115 of the treatment group developed recurrence of endometriosis with no recurrence reported in the no-treatment group. This was not statistically significant. No woman was re-operated on in the no-treatment group compared with 2/115 in the treatment group.

AUTHORS' CONCLUSIONS

Hormone replacement therapy for women with endometriosis in post-surgical menopause could result in pain and disease recurrence. However, the evidence in the literature is not strong enough to suggest depriving severely symptomatic patients from this treatment. There is a need for more randomised controlled studies.

CYP17 and CYP19 gene polymorphisms in women affected with endometriosis

OBJECTIVE

To investigate whether CYP17 T>C polymorphism and polymorphisms C1558T and Val80 of CYP19 are related to endometriosis.

DESIGN

Clinical study.

PATIENT(S)

Women affected with endometriosis (n = 104) and control group (n = 86). The diagnosis of endometriosis was confirmed by the histologic examination of the endometriotic lesions.

RESULT(S)

In patients affected with endometriosis, we observed that AA and CC genotypes were significantly represented in Val80 and C1558T polymorphisms of CYP19.

CONCLUSION(S)

The molecular mechanisms that underlie the development of endometriosis are unclear. Both environmental and genetic factors are involved in the pathogenesis of the disease. The inheritable susceptibility to endometriosis justifies the growing interest in identifying genes and/or genetic polymorphisms that predispose women to an increased risk of developing endometriosis. The identification of single-nucleotide polymorphism (SNP), probably linked to endometriosis, could help to explain its pathogenesis.

Functional genetic polymorphisms and female reproductive disorders: part II--endometriosis

BACKGROUND

Endometriosis has a strong genetic component, and numerous genetic studies have been reported.

METHODS

We have systematically reviewed these studies and included 114 in our final selection.

RESULTS

We found no consistent evidence linking endometriosis with specific polymorphisms in genes encoding inflammatory mediators, proteins involved in sex steroid metabolism, vascular function and tissue remodelling. Although a number of polymorphisms have been associated with endometriosis in selected populations, the associations have not been independently confirmed, either because only single studies were carried out on these markers/genes or because other studies reported no association. The most solid evidence linking specific polymorphisms to endometriosis came from studies investigating glutathione-S-transferase, a phase II detoxification enzyme. Carriage of the GSTT1 null deletion variant showed consistent association with endometriosis with a 29% increased risk; however, it cannot be excluded that this result was due to publication bias, and this association should be independently confirmed in large-scale, well-designed case–control studies.

CONCLUSIONS

The evidence of an association between genetic polymorphisms and endometriosis is weak. Carriage of the GSTT1 null deletion may moderately increase the risk of this disease. We suggest that the methodology of association studies should be improved in order to identify and validate associations in endometriosis.

[Association of HLA-A, B antigens with susceptibility to advanced endometriosis in Koreans]

BACKGROUND

Endometriosis is defined as the presence of endometrial tissue outside the uterus, causing diverse diseases, including infertility, pelvic pain, dysmenorrhea, and constipation. While there is a growing body of evidence that genetic and immunologic factors play important roles in the pathogenesis of the disease, HLA-A, B antigens have been reported to be associated with the risk of endometriosis in the Japanese population. This study was performed to determine whether the susceptibility to advanced endometriosis is also associated with HLA-A, B antigens in the Korean population, which is the closest ethnic group to Japanese.

METHODS

We recruited 50 Korean patients with advanced endometriosis confirmed by surgical and histolological examinations. Distribution of HLA-A and B antigens was compared with that of 200 unrelated ethnically matched individuals. HLA-A and B genotyping was carried out using a PCRsequence specific oligonucleotide hybridization method.

RESULTS

An increased frequency of B39 was observed in endometriosis patients compared with control subjects, but the difference was not statistically significant after correcting for multiple comparisons (4.0% patients vs 0.8% controls, OR=5.5, 95% CI=1.21-25.04, P=0.03, P(c)=not significant). No significant differences were found between the patients with endometriosis and the general control group with regards to the distribution of other HLA-A and B antigens.

CONCLUSIONS

The findings of the present study suggest that the susceptibility to advanced endometriosis, unlike in the Japanese population, is not associated with HLA-A, B antigens in the Korean population.

Intron 1 and exon 1 alpha estrogen receptor gene polymorphisms in women with endometriosis

OBJECTIVE

To evaluate the association of intron 1 and exon 1 polymorphisms in the estrogen receptor alpha gene (ER-alpha) with endometriosis in women.

DESIGN

Association study.

SETTING

Endometriosis Unit, Federal University of São Paulo.

PATIENT(S)

The control group consisted of volunteers older than 45 years who had no evidence of endometriosis antecedents. Two groups with the disease were evaluated: the first group had stage I or II endometriosis and the second group stage III or IV.

INTERVENTION(S)

Polymerase chain reaction (PCR) followed by digestion with HaeIII and MspI endonucleases (RFLP) were applied to detect intron 1 and exon 1 polymorphisms, respectively, in a total of 125 controls and 105 affected women.

MAIN OUTCOME MEASURE(S)

Frequency and distribution of HaeIII and MspI polymorphisms in ER-alpha.

RESULT(S)

No significant differences in the frequency of polymorphisms either in intron 1 or exon 1 of ER-alpha were found when endometriosis patients were compared with control subjects. Furthermore, the frequency of ER-alpha polymorphisms within the two different groups of patients with disease was statistically similar. The odds ratio between presence of intron 1 single-nucleotide polymorphisms (SNP) and endometriosis was 0.904, and the odds ratio between exon 1 SNP and endometriosis was 0.976.

CONCLUSION(S)

The evaluated polymorphisms were not associated with endometriosis.

Role of shigella infection in endometriosis: A novel hypothesis

Endometriosis is the presence of endometrial cells and stroma at ectopic sites outside the uterine cavity. The natural history of endometriosis is uncertain, its etiology unknown, the clinical presentation inconsistent, diagnosis difficult and the treatment poorly standardized. It causes significant morbidity due to pelvic pain and infertility among 15-25% of women during their reproductive age. The benign disease causes peritoneal inflammation, fibrosis, adhesions and ovarian cysts but displays features of malignancy, like neo-vascularization, local invasion and distant metastasis. Mechanical, hormonal, immunological, environmental and genetic factors have been implicated in its etiology but provide inconclusive explanations. Present study was carried out on ectopic and eutopic endometriotic tissue specimens collected during laproscopy/laprotomy from cases of endometriosis. mRNA was isolated from the tissues and converted to cDNA by RT and subsequently subjected to differential display Polymerase Chain Reaction using seven sets of arbitrary primers. A unique band was identified only in the ectopic endometriotic tissue, which was sequenced. BLAST search results revealed sequence homology to shigella bacterial DNA leading us to hypothesize that infection may be playing a role in the etiology of endometriosis. This is the first report implicating the role of bacterial infection in the etiology of endometriosis. Shigella is known to invade the mucosa of the colon through the feco-oral route causing Shigellosis. The pathogenesis of shigellosis involves inflammation, ulceration, haemorrhage, tissue destruction and fibrosis of the colonic mucosa resulting in abdominal pain and diarrhoea/dysentery, this is similar to the pathogenesis of endometriosis which also involves inflammation, haemorrhage, tissue destruction and fibrotic adhesions of the pelvic peritoneum resulting in abdominal pain and infertility. The non-motile shigella bacteria invade the deeper mucosal layers by travelling from cell to cell of colonic epithelium, reaching the lamina propria of the colonic mucosa. We propose that, by the same mechanism, the bacteria travel across the colon wall to reach the outer peritoneal surface of the colon, which is in close proximity to the posterior uterine surface in the Pouch of Douglas, the site which incidentally happens to be the commonest site of early endometriosis. Our hypothesis therefore proposes that shigella or shigella-like organisms may be the trigger for the initiation of immunological changes in the pelvic peritoneum causing endometriosis. Once the endometrial cells are implanted at ectopic sites they are sustained by hormones and angiogenic factors. Hence "Infection hypothesis" provides a novel explanation for the etiopathogenesis of endometriosis.