Intra-tissue steroid profiling indicates differential progesterone and testosterone metabolism in the endometrium and endometriosis lesions

Single-cell analysis identifies distinct macrophage phenotypes associated with prodisease and proresolving functions in the endometriotic niche

Endometriosis negatively impacts the health-related quality of life of 190 million women worldwide. Novel advances in nonhormonal treatments for this debilitating condition are desperately needed. Macrophages play a vital role in the pathophysiology of endometriosis and represent a promising therapeutic target. In the current study, we revealed the full transcriptomic complexity of endometriosis-associated macrophage subpopulations using single-cell analyses in a preclinical mouse model of experimental endometriosis. We have identified two key lesion-resident populations that resemble i) tumor-associated macrophages (characterized by expression of Folr2, Mrc1, Gas6, and Ccl8+) that promoted expression of Col1a1 and Tgfb1 in human endometrial stromal cells and increased angiogenic meshes in human umbilical vein endothelial cells, and ii) scar-associated macrophages (Mmp12, Cd9, Spp1, Trem2+) that exhibited a phenotype associated with fibrosis and matrix remodeling. We also described a population of proresolving large peritoneal macrophages that align with a lipid-associated macrophage phenotype (Apoe, Saa3, Pid1) concomitant with altered lipid metabolism and cholesterol efflux. Gain of function experiments using an Apoe mimetic resulted in decreased lesion size and fibrosis, and modification of peritoneal macrophage populations in the preclinical model. Using cross-species analysis of mouse and human single-cell datasets, we determined the concordance of peritoneal and lesion-resident macrophage subpopulations, identifying key similarities and differences in transcriptomic phenotypes. Ultimately, we envisage that these findings will inform the design and use of specific macrophage-targeted therapies and open broad avenues for the treatment of endometriosis.

Corticosteroids, androgens, progestogens and oestrogens in the endometrial microenvironment, and their association with endometrial progression and function

RESEARCH QUESTION

How does the intracrine action of progestagens, oestrogens, androgens and corticosteroids affect endometrial tissue progression and function?

DESIGN

In this prospective observational study, 76 patients (<50 years old, no uterine pathologies and at least one failed IVF cycle) undergoing endometrial biopsy collection for endometrial evaluation between 2018 and 2021 were included. The concentrations of 11 steroid metabolites (cortisone, cortisol, progesterone, oestrone, 2-methoxyestrone, oestradiol, oestriol, testosterone, androstenedione, 17α-hydroxyprogesterone and 17-hydroxypregnenolone) were measured by ultra-performance liquid chromatography-tandem mass spectrometry in the endometrial tissue samples collected during the mid-secretory phase. Endometrial dating and reproductive outcomes (relative to the next good-quality fresh or frozen embryo transfer after the biopsy) were analysed in relation to endometrial steroid concentrations using Barnard's test; correlations between metabolite concentrations were measured by Pearson's correlation co-efficient.

RESULTS

Endometrial cortisol concentrations increased with age, whereas oestrone and 17α-hydroxyprogesterone concentrations had inverse relationships with body mass index (all P < 0.05). No statistically significant differences were found in age or body mass index related to endometrial progression and reproductive outcomes. Low endometrial progesterone (<40.07 μg/g), along with high endometrial cortisol (>2.18 ng/g) and testosterone concentrations (≥0.52 ng/g), were mainly associated with out-of-phase endometria. Although low oestrone (<21.27 ng/g) and high androstenedione endometrial concentrations (≥1.35 ng/g) impaired reproductive success, low oestradiol (<1.15 ng/g) endometrial concentrations favoured conception (all P < 0.05).

CONCLUSIONS

In addition to progesterone and oestrogens, other steroid hormones are involved in intracrine signalling, and are probably necessary for acquiring adequate endometrial competence and supporting conception.

The effect of androgens on the risk of endometriosis sub-phenotypes and ovarian neoplasms: A Mendelian randomization study

Endometriosis is a complex gynecological pathology with a broad spectrum of symptoms, affecting around 10% of reproductive-aged women. Ovarian cancer (OC) is a heterogeneous disease for which we lack effective diagnostic and therapeutic strategies. The etiology and pathogenesis of both diseases remain ambiguous. Androgens in endometriosis could have a distinct role beyond serving as estrogen sources, whereas in the case of serous OC could be important in the formation of precursor lesions which ultimately lead to tumor formation. Here we performed two-sample Mendelian randomization (MR) analysis to examine the causal relationship between the androgen precursor - dehydroepiandrosterone sulphate (DHEAS), bioactive androgen - testosterone (T), androgen metabolite - androsterone sulphate, steroid hormone binding globulin (SHBG) and albumin and the risk of endometrioses of various sub-phenotypes and ovarian neoplasms across the benign-borderline-malignant spectrum. Stringent quality control procedures were followed to select eligible instrumental variables that were strongly associated with the selected exposures, sensitivity analyses were performed to assess the heterogeneities, horizontal pleiotropy, and stabilities of SNPs in endometriosis and ovarian neoplasms. We discovered an inverse association between genetically predicted levels of all androgens and risk of endometriosis, the same trend was most evident in the ovarian sub-phenotype. Total T levels were also inversely associated with peritoneal sub-phenotype of endometriosis. Likewise, T was causally associated with decreased risk of clear-cell OC, an endometriosis-associated OC subtype, and with malignant serous OC of both low- and high-grade, but with higher risk of their counterpart of low malignant potential. These findings support further investigation of androgen's action at a molecular level in ovary-associated endometriotic lesions, clear cell ovarian tumors and serous precursor lesions.

Horizons in Endometriosis: Proceedings of the Montreux Reproductive Summit, 14-15 July 2023

Endometriosis is a complex and chronic gynaecological disorder that affects millions of women worldwide, leading to significant morbidity and impacting reproductive health. This condition affects up to 10% of women of reproductive age and is characterised by the presence of endometrial-like tissue outside the uterus, potentially leading to symptoms such as chronic pelvic pain, dysmenorrhoea, dyspareunia, and infertility. The Montreux summit brought a number of experts in this field together to provide a platform for discussion and exchange of ideas. These proceedings summarise the six main topics that were discussed at this summit to shed light on future directions of endometriosis classification, diagnosis, and therapeutical management. The first question addressed the possibility of preventing endometriosis in the future by identifying risk factors, genetic predispositions, and further understanding of the pathophysiology of the condition to develop targeted interventions. The clinical presentation of endometriosis is varied, and the correlation between symptoms severity and disease extent is unclear. While there is currently no universally accepted optimal classification system for endometriosis, several attempts striving towards its optimisation - each with its own advantages and limitations - were discussed. The ideal classification should be able to reconcile disease status based on the various diagnostic tools, and prognosis to guide proper patient tailored management. Regarding diagnosis, we focused on future tools and critically discussed emerging approaches aimed at reducing diagnostic delay. Preserving fertility in endometriosis patients was another debatable aspect of management that was reviewed. Moreover, besides current treatment modalities, potential novel medical therapies that can target underlying mechanisms, provide effective symptom relief, and minimise side effects in endometriotic patients were considered, including hormonal therapies, immunomodulation, and regenerative medicine. Finally, the question of hormonal substitution therapy after radical treatment for endometriosis was debated, weighing the benefits of hormone replacement.

The pathophysiological role of estrogens in the initial stages of pregnancy: molecular mechanisms and clinical implications for pregnancy outcome from the periconceptional period to end of the first trimester

BACKGROUND

Estrogens regulate disparate female physiological processes, thus ensuring reproduction. Altered estrogen levels and signaling have been associated with increased risks of pregnancy failure and complications, including hypertensive disorders and low birthweight babies. However, the role of estrogens in the periconceptional period and early pregnancy is still understudied.

OBJECTIVE AND RATIONALE

This review aims to summarize the current evidence on the role of maternal estrogens during the periconceptional period and the first trimester of pregnancies conceived naturally and following ART. Detailed molecular mechanisms and related clinical impacts are extensively described.

SEARCH METHODS

Data for this narrative review were independently identified by seven researchers on Pubmed and Embase databases. The following keywords were selected: 'estrogens' OR 'estrogen level(s)' OR 'serum estradiol' OR 'estradiol/estrogen concentration', AND 'early pregnancy' OR 'first trimester of pregnancy' OR 'preconceptional period' OR 'ART' OR 'In Vitro Fertilization (IVF)' OR 'Embryo Transfer' OR 'Frozen Embryo Transfer' OR 'oocyte donation' OR 'egg donation' OR 'miscarriage' OR 'pregnancy outcome' OR 'endometrium'.

OUTCOMES

During the periconceptional period (defined here as the critical time window starting 1 month before conception), estrogens play a crucial role in endometrial receptivity, through the activation of paracrine/autocrine signaling. A derailed estrogenic milieu within this period seems to be detrimental both in natural and ART-conceived pregnancies. Low estrogen levels are associated with non-conception cycles in natural pregnancies. On the other hand, excessive supraphysiologic estrogen concentrations at time of the LH peak correlate with lower live birth rates and higher risks of pregnancy complications. In early pregnancy, estrogen plays a massive role in placentation mainly by modulating angiogenic factor expression-and in the development of an immune-tolerant uterine micro-environment by remodeling the function of uterine natural killer and T-helper cells. Lower estrogen levels are thought to trigger abnormal placentation in naturally conceived pregnancies, whereas an estrogen excess seems to worsen pregnancy development and outcomes.

WIDER IMPLICATIONS

Most current evidence available endorses a relation between periconceptional and first trimester estrogen levels and pregnancy outcomes, further depicting an optimal concentration range to optimize pregnancy success. However, how estrogens co-operate with other factors in order to maintain a fine balance between local tolerance towards the developing fetus and immune responses to pathogens remains elusive. Further studies are highly warranted, also aiming to identify the determinants of estrogen response and biomarkers for personalized estrogen administration regimens in ART.

Impact of Heterotropic Allosteric Modulation on the Time-Dependent Inhibition of Cytochrome P450 3A4

The current study was designed to investigate the influence of allosteric effectors on the metabolism of the prototypical cytochrome P450 (CYP) 3A4 substrate midazolam (MDZ), and on the determination in vitro time-dependent inhibition (TDI) of CYP3A4 using human liver microsomes (HLM). As the concentration of midazolam increased to 250 µM in HLMs, homotropic cooperativity resulted in a decrease in the 1'-hydroxymidazolam to 4-hydroxymidazolam ratio to a maximum of 1.1. The presence of varying concentrations of testosterone, progesterone (PGS), or carbamazepine (CBZ) in HLMs with MDZ could recapitulate the effect of homotropic cooperativity such that the formation rates of the 1'hydroxymidazolam and 4-hydroxymidazolam were equal even at low concentrations of MDZ. The presence of PGS (10 or 100 µM) and CBZ (100 or 1000 µM) in in vitro TDI determination of four known CYP3A4 time-dependent inactivators (clarithromycin, troleandomycin, mibefradil, raloxifene) simultaneously decreased potency and inactivation rate constant, resulting in fold changes in inactivation efficiency on average of 1.6-fold and 13-fold for the low and high concentrations of allosteric modulator tested, respectively. The formation of a metabolic-intermediate complex (MIC) for clarithromycin and troleandomycin decreased in the presence of the allosteric modulators in a concentration-dependent manner, reaching a new steady state formation that could not be overcome with increased incubation time. Maximum reduction of the MIC formed by clarithromycin was up to ∼91%, while troleandomycin MIC decreased up to ∼31%. These findings suggest that the absence of endogenous allosteric modulators may contribute to the poor translation of HLM-based drug-drug interaction predictions. SIGNIFICANCE STATEMENT: The reported overprediction of in vitro human liver microsome time-dependent inhibition of CYP3A4 and observed drug interactions in vivo remains an issue in drug development. We provide characterization of allosteric modulators on the CYP3A4 metabolism of the prototypical substrate midazolam, demonstrating the ability of the modulators to recapitulate the homotropic cooperativity of midazolam. Furthermore, we demonstrate that allosteric heterotropic cooperativity of CYP3A4 can impact the time-dependent inhibition kinetics of known mechanisms-based inhibitors, providing a potential mechanism to explain the overprediction.

An integrative analysis of endometrial steroid metabolism and transcriptome in relation to endometrial receptivity in in vitro fertilization patients

OBJECTIVE

To study the relationship between the steroid concentration in the endometrium, in serum, and the gene expression level of steroid-metabolizing enzymes in the context of endometrial receptivity in in vitro fertilization (IVF) patients.

DESIGN

Case-control study of 40 IVF patients recruited in the SCRaTCH study (NTR5342), a randomized controlled trial investigating pregnancy outcome after "endometrial scratching." Endometrial biopsies and serum were obtained from patients with a first failed IVF cycle randomized to the endometrial scratch in the midluteal phase of the natural cycle before the next fresh embryo transfer during the second IVF cycle.

SETTING

University hopsital.

PATIENTS

Twenty women with clinical pregnancy were compared with 20 women who did not conceive after fresh embryo transfer. Cases and controls were matched for primary vs. secondary infertility, embryo quality, and age.

INTERVENTION

None.

MAIN OUTCOME MEASURE(S)

Steroid concentrations in endometrial tissue homogenates and serum were measured with liquid chromatography-mass spectrometry. The endometrial transcriptome was profiled by RNA-sequencing, followed by principal component analysis and differential expression analysis. False discovery rate-adjusted and log-fold change >|0.5| were selected as the threshold for differentially expressed genes.

RESULT(S)

Estrogen levels were comparable in both serum (n = 16) and endometrium (n = 40). Androgens and 17-hydroxyprogesterone were higher in serum than that in endometrium. Although steroid levels did not vary between pregnant and nonpregnant groups, subgroup analysis of primary women with infertility showed a significantly lower estrone concentration and estrone:androstenedione ratio in serum of the pregnant group (n = 5) compared with the nonpregnant group (n = 2). Expression of 34 out of 46 genes encoding the enzymes controlling the local steroid metabolism was detected, and estrogen receptor β gene was differentially expressed between pregnant and nonpregnant women. When only the primary infertile group was considered, 28 genes were differentially expressed between pregnant and nonpregnant women, including HSD11B2, that catalyzes the conversion of cortisol into cortisone.

CONCLUSION(S)

Steroidomic and transcriptomic analyses show that steroid concentrations are regulated by the local metabolism in the endometrium. Although no differences were found in endometrial steroid concentration in the pregnant and nonpregnant IVF patients, primary women with infertility showed deviations in steroid levels and gene expression, indicating that a more homogeneous patient group is required to uncover the exact role of steroid metabolism in endometrial receptivity.

CLINICAL TRIAL REGISTRATION NUMBER

The study was registered in the Dutch trial registry (www.trialregister.nl), registration number NL5193/NTR5342, available at https://trialsearch.who.int/Trial2.aspx?TrialID=NTR6687. The date of registration is July 31, 2015. The first enrollment is on January 1, 2016.

Novel aldo-keto reductase 1C3 inhibitor affects androgen metabolism but not ovarian function in healthy women: a phase 1 study

OBJECTIVE

Aldo-keto reductase 1C3 (AKR1C3) has been postulated to be involved in androgen, progesterone, and estrogen metabolism. Aldo-keto reductase 1C3 inhibition has been proposed for treatment of endometriosis and polycystic ovary syndrome. Clinical biomarkers of target engagement, which can greatly facilitate drug development, have not yet been described for AKR1C3 inhibitors. Here, we analyzed pharmacodynamic data from a phase 1 study with a new selective AKR1C3 inhibitor, BAY1128688, to identify response biomarkers and assess effects on ovarian function.

DESIGN

In a multiple-ascending-dose placebo-controlled study, 33 postmenopausal women received BAY1128688 (3, 30, or 90 mg once daily or 60 mg twice daily) or placebo for 14 days. Eighteen premenopausal women received 60 mg BAY1128688 once or twice daily for 28 days.

METHODS

We measured 17 serum steroids by liquid chromatography-tandem mass spectrometry, alongside analysis of pharmacokinetics, menstrual cyclicity, and safety parameters.

RESULTS

In both study populations, we observed substantial, dose-dependent increases in circulating concentrations of the inactive androgen metabolite androsterone and minor increases in circulating etiocholanolone and dihydrotestosterone concentrations. In premenopausal women, androsterone concentrations increased 2.95-fold on average (95% confidence interval: 0.35-3.55) during once- or twice-daily treatment. Note, no concomitant changes in serum 17β-estradiol and progesterone were observed, and menstrual cyclicity and ovarian function were not altered by the treatment.

CONCLUSIONS

Serum androsterone was identified as a robust response biomarker for AKR1C3 inhibitor treatment in women. Aldo-keto reductase 1C3 inhibitor administration for 4 weeks did not affect ovarian function.ClinicalTrials.gov Identifier: NCT02434640; EudraCT Number: 2014-005298-36.

Emerging hallmarks of endometriosis metabolism: A promising target for the treatment of endometriosis

Endometriosis, characterized by ectopic endometrium growth in the extrauterine environment, is one of the most notable diseases of the female reproductive system. Worldwide, endometriosis affects nearly 10 % of women in their reproductive years and causes a significant decline in quality of life. Despite extensive investigations of endometriosis over the past years, the mechanisms of endometriosis pathogenesis remain unclear. In recent years, metabolic factors have increasingly been considered factors in endometriosis. There is compelling evidence regarding the progress of endometriosis in the context of severe metabolic dysfunction. Hence, the curative strategies and ongoing attempts to conquer endometriosis might start with metabolic pathways. This review focuses on metabolic mechanisms and summarizes current research progress. These findings provide valuable information for the non-intrusive diagnosis of the disease and may contribute to the understanding of the pathogenesis of endometriosis.

Androgen Signaling in Uterine Diseases: New Insights and New Targets

Common uterine diseases include endometriosis, uterine fibroids, endometrial polyps, endometrial hyperplasia, endometrial cancer, and endometrial dysfunction causing infertility. Patients with uterine diseases often suffer from abdominal pain, menorrhagia, infertility and other symptoms, which seriously impair their health and disturb their lives. Androgens play important roles in the normal physiological functions of the uterus and pathological progress of uterine diseases. Androgens in women are synthesized in the ovaries and adrenal glands. The action of androgens in the uterus is mainly mediated by its ligand androgen receptor (AR) that regulates transcription of the target genes. However, much less is known about the signaling pathways through which androgen functions in uterine diseases, and contradictory findings have been reported. This review summarizes and discusses the progress of research on androgens and the involvement of AR in uterine diseases. Future studies should focus on developing new therapeutic strategies that precisely target specific AR and their related signaling pathways in uterine diseases.

Revisiting the physiological role of androgens in women

INTRODUCTION

Extensive research underlines the critical functions of androgens in females. Nevertheless, the precise mechanisms of their action are poorly understood. Here, we review the existing literature regarding the physiological role of androgens in women throughout life.

AREAS COVERED

Several studies show that androgen receptors (ARs) are broadly expressed in numerous female tissues. They are essential for many physiological processes, including reproductive, sexual, cardiovascular, bone, muscle, and brain health. They are also involved in adipose tissue and liver function. Androgen levels change with the menstrual cycle and decrease in the first decades of life, independently of menopause.

EXPERT OPINION

To date, studies are limited by including small numbers of women, the difficulty of dosing androgens, and their cyclical variations. In particular, whether androgens play any significant role in regulating the establishment of pregnancy is poorly understood. The neural functions of ARs have also been investigated less thoroughly, although it is expressed at high levels in brain structures. Moreover, the mechanism underlying the decline of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) with age is unclear. Other factors, including estrogen's effect on adrenal androgen production, reciprocal regulation of ARs, and non-classical effects of androgens, remain to be determined.

Endometrial factors in the implantation failure spectrum: protocol of a MUltidisciplinary observational cohort study in women with Repeated Implantation failure and recurrent Miscarriage (MURIM Study)

INTRODUCTION

Women with repeated implantation failure (RIF) and unexplained recurrent miscarriage (RM) are proposed to be at opposite ends of the implantation spectrum, with RM representing an overly receptive endometrium (implantation of genetically aberrant or poor-quality embryos) versus RIF representing an overly selective endometrium (no implantation even with good quality embryos). In both cases, often no explanation for reproductive failure can be found and although promising add-on treatments have been introduced, therapeutic options are frequently limited to supportive care. Both RM and RIF are multifactorial and research indicates that the interplay between steroidogenesis, uterine natural killer (uNK) cells and the microbiome determine the capacity of the endometrium to be a biosensor for invading embryos. Our objective is to elucidate whether there is a difference in endometrial receptivity parameters (ie, steroid metabolism, uNK cells and the microbiome) between women aged 18-38 years with reproductive failure (RIF and RM), and fertile controls.

METHODS AND ANALYSIS

Single-centre, observational cohort study. Endometrial biopsies, vaginal swabs and peripheral blood will be collected during the window of implantation and menstrual blood in the subsequent menstruation. The study parameters are the steroid profile (steroid levels and mRNA levels, protein expression and activity of steroid enzymes) in endometrial tissue and peripheral blood, as well as the activating or inhibitory phenotype of uNK cells based on receptor expression in menstrual blood and endometrial tissue and determination of the vaginal and endometrial microbiome using the inter spacer bacterial profiling technique.

ETHICS AND DISSEMINATION

The protocol is approved by the local medical ethical review committee at the Maastricht University Medical Centre. Findings from this study will be shared with the academic and medical community and the patient organisations to optimise and individualise medical care of patients with implantation failure and miscarriages.

TRIAL REGISTRATION NUMBER

NTR7571, registered 28 February 2019.

Uterine bleeding: how understanding endometrial physiology underpins menstrual health

Menstruation is a physiological process that is typically uncomplicated. However, up to one third of women globally will be affected by abnormal uterine bleeding (AUB) at some point in their reproductive years. Menstruation (that is, endometrial shedding) is a fine balance between proliferation, decidualization, inflammation, hypoxia, apoptosis, haemostasis, vasoconstriction and, finally, repair and regeneration. An imbalance in any one of these processes can lead to the abnormal endometrial phenotype of AUB. Poor menstrual health has a negative impact on a person's physical, mental, social, emotional and financial well-being. On a global scale, iron deficiency and iron deficiency anaemia are closely linked with AUB, and are often under-reported and under-recognized. The International Federation of Gynecology and Obstetrics have produced standardized terminology and a classification system for the causes of AUB. This standardization will facilitate future research endeavours, diagnosis and clinical management. In a field where no new medications have been developed for over 20 years, emerging technologies are paving the way for a deeper understanding of the biology of the endometrium in health and disease, as well as opening up novel diagnostic and management avenues.

The Modulatory Effect of Adipose-Derived Stem Cells on Endometrial Polyp Fibroblasts

Endometrial polyps (EPs) are benign overgrowths of the endometrium, with the potential to cause severe complications, ranging from discomfort to inflammation and infertility. Dysfunction of endometrial fibroblasts may be a critical component leading to the development of polyps. While surgical intervention is the common remedy for severe cases, it comes with drawbacks, including infection, bleeding, and risk of damage to the cervix and adjacent tissues. Adipose-derived mesenchymal stromal cells (ASCs) are at the focus of modern medicine, as key modulators of tissue homeostasis, inflammation and tissue repair, rendering them prime candidate agents for tissue regeneration and cell-based therapies. In the current work, endometrial polyps were isolated from patients admitted to the OB/GYN department at the Galilee Medical Center and extracted fibroblasts (EPFs) were isolated and characterized. ASCs were isolated from healthy patients. The effect of EPF- and ASC-conditioned media (CM) on polyp-derived fibroblasts was evaluated, in both 2D and 3D assays, as well as on the expression of matrix-related gene expression. Herein, EPFs exposed to ASC-CM exhibited reduced migration, invasion, contraction of hydrogels, and extracellular matrix deposition, compared to those exposed to EPF-CM. Altogether, the current work suggests that ASCs may have a modulating effect on fibroblasts involved in forming endometrial polyps and may serve as the basis for conservative treatment strategies aimed at treating severe cases of EPs.

Parallel targeted and non-targeted quantitative analysis of steroids in human serum and peritoneal fluid by liquid chromatography high-resolution mass spectrometry

We developed and validated a liquid chromatography high-resolution mass spectrometry method for the absolute quantification of 51 steroids for clinical analysis of human serum and, for the first time, peritoneal fluid. Data acquisition was performed in both targeted and untargeted mode simultaneously, thus allowing the accurate and precise quantification of the main components of the classical steroid pathways (17 steroids) as well as the analysis of 34 additional non-classical steroids. For targeted analysis, validation was performed according to FDA guidelines, resulting, among other parameters, in accuracy < 13% RSD and precision < 10% relative error, for both inter- and intra-day validation runs. By establishing steroid-specific response factors, the calibration curves of the targeted analytes can be extended to untargeted analytes. This approach opens novel possibilities for the post hoc analysis of clinical samples as the data can be examined for virtually any steroid even after data acquisition, enabling facile absolute quantification once a standard becomes available. We demonstrate the applicability of the approach to evaluate the differences in steroid content between peripheral serum and peritoneal fluid across the menstrual cycle phases, as well as the effect of the synthetic gestagen dienogest on the steroid metabolome.

HOXA10 Regulates the Synthesis of Cholesterol in Endometrial Stromal Cells

BACKGROUND

The expression of homeobox A10 (HOXA10) in endometrial stromal cells is regulated by steroid hormones, especially by estrogen. As a precursor molecule of estrogen, abnormal cholesterol metabolism is significantly positively correlated with endometriosis. The purpose of this study was to explore the regulation of HOXA10 on cholesterol synthesis in endometrial stromal cells.

METHOD

mRNA expression data of eutopic endometrial stromal cell (ESC) and ovarian endometriotic cysts stromal cell (OESC) were download from the Gene Expression Omnibus (GEO) databases. Overexpression and silence of HOXA10 were conducted in cultured ESC and subjected to mRNA sequencing. The differentially expressed genes (DEGs) were selected by analyzing the sequencing data. Weighted gene co-expression network analysis (WGCNA) was applied to identify the key genes associated with HOXA10. The methylation rate of HOXA10 CpGs and the correlation between HOXA10 expression and the methylation in eutopic endometrial tissue (EU) and ovarian cyst (OC) were analyzed.

RESULTS

HOXA10 in ESC was significantly higher expressed than that in OESC. Six key genes (HMGCR, MSMO1, ACAT2, HMGCS1, EBP, and SQLE), which were regulated by HOXA10, were identified from the salmon4 module by WGCNA. All these key genes were enriched in cholesterol synthesis. Moreover, the expression of HOXA10 was negatively related to its CpGs methylation rate.

CONCLUSION

In this study, six key genes that were regulated by HOXA10 were selected, and all of them were enriched in cholesterol synthesis. This finding provided a new insight into the metabolic mechanism of cholesterol in ESC. It also provided a potential treatment strategy for cholesterol metabolism maladjustment in patients with ovarian endometriosis.

Analysis of serum and endometrial progesterone in determining endometrial receptivity

STUDY QUESTION

Is there a relationship between serum and endometrial progesterone (P4) levels, including P4 and metabolites (oestrone, oestradiol and 17α-hydroxyprogesterone), and endometrial receptivity?

SUMMARY ANSWER

Serum P4 levels were not correlated with endometrial P4, nor associated with endometrial receptivity as determined by the ERA® test; however, endometrial P4 and 17α-hydroxyprogesterone levels were positively correlated and related to endometrial receptivity by ERA.

WHAT IS KNOWN ALREADY

Acquisition of endometrial receptivity is governed by P4, which induces secretory transformation. A close relationship between serum P4 and pregnancy outcome is reported for hormone replacement therapy (HRT) cycles. However, the relationship between serum and uterine P4 levels has not been described, and it is unknown whether uterine receptivity depends more on serum or uterine P4 levels.

STUDY DESIGN, SIZE, DURATION

A prospective cohort study was performed during March 2018-2019 in 85 IVF patients undergoing an evaluation-only HRT cycle with oestradiol valerate (6 mg/day) and micronised vaginal progesterone (400 mg/12 h).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients were under 50 years of age, had undergone at least one failed IVF cycle, had no uterine pathology, and had adequate endometrial thickness (> 6.5 mm). The study was conducted at IVI Valencia and IVI Foundation. An endometrial biopsy and a blood sample were collected after 5 days of P4 vaginal treatment. Measures included serum P4 levels, ERA®-based evaluation of endometrial receptivity, and endometrial P4 levels along with metabolites (oestrone, oestradiol and 17α-hydroxyprogesterone) measured by ultra-performance liquid chromatography-tandem mass spectrometry.

MAIN RESULTS AND THE ROLE OF CHANCE

Seventy-nine women were included (mean age: 39.9 ± 4.6, BMI: 24.2 ± 3.9 kg/m2, endometrial thickness: 8.2 ± 1.4 mm). The percentage of endometria indicated as receptive by ERA® was 40.5%. When comparing receptive versus non-receptive groups, no differences were observed in baseline characteristics nor in steroid hormones levels in serum or endometrium. No association between serum P4 and endometrial steroid levels or ERA result was found (P < 0.05). When the population was stratified according to metabolite concentration levels, endometrial P4 and 17α-hydroxyprogesterone were significantly associated with endometrial receptivity (P < 0.05). A higher proportion of receptive endometria by ERA was observed when endometrial P4 levels were higher than 40.07 µg/ml (relative maximum) and a lower proportion of receptive endometria was associated with endometrial 17α-hydroxyprogesterone lower than 0.35 ng/ml (first quartile). A positive correlation R2 = 0.67, P < 0.001 was observed between endometrial P4 and 17α-hydroxyprogesterone levels.

LIMITATIONS, REASONS FOR CAUTION

This study did not analyse pregnancy outcomes. Further, the findings can only be extrapolated to HRT cycles with micronised vaginal progesterone for luteal phase support.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that the combined benefits of different routes of progesterone administration for luteal phase support could be leveraged to ensure an adequate concentration of progesterone both in the uterus and in the bloodstream. Further studies will confirm whether this method can optimise both endometrial receptivity and live birth rate. Additionally, targeted treatment to increase P4 endometrial levels may normalise the timing of the window of implantation without needing to modify the progesterone administration day.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by the IVI-RMA Valencia (1706-VLC-051-EL) and Consellería d'Educació, Investigació, Cultura, i esport Generalitat Valenciana (Valencian Government, Spain, GV/2018//151). Almudena Devesa-Peiro (FPU/15/01398) and Cristina Rodriguez-Varela (FPU18/01657) were supported by the FPU program fellowship from the Ministry of Science, Innovation and Universities (Spanish Government). P.D.-G. is co-inventor on the ERA patent, with non-economic benefits. The other authors have no competing interests.

TRIAL REGISTRATION NUMBER

NCT03456375.

Mild hyperandrogenemia in presence/absence of a high-fat, Western-style diet alters secretory phase endometrial transcriptome in nonhuman primates

OBJECTIVE

To identify novel transcriptomic changes to eutopic endometrium by exposure to chronic mild hypernadrogenemia (testosterone [T]) with/without exposure to an obesogenic Western-style diet (WSD).

DESIGN

Two-by-two factorial arrangement of treatments.

SETTING

National primate research center.

ANIMALS

Rhesus macaque females were chronically exposed to T and/or consumed a WSD from menarche through adulthood. After 4.5 years of treatment, Tru-Cut endometrial biopsies were obtained at the midsecretory phase (n = 6-4/group), and paired-end sequencing of RNA was performed. Several females in the T, WSD, and T+WSD cohorts developed endometriosis within 6 months of biopsy; a separate analysis was performed contrasting diagnosis of endometriosis stage 0-2 versus stages 3 and 4 (American Society for Reproductive Medicine revised criteria).

INTERVENTIONS

Chronic exposure to mild elevation of T (~five-fold elevation) and/or WSD from menarche until adulthood.

MAIN OUTCOME MEASURES

Limma voom empirical Bayes pipeline was performed to detect differentially expressed RNAs (DEs) significantly impacted by treatments and endometriosis severity. Differentially expressed RNAs were then interrogated by Ingenuity Pathway Analyses and Protein Analysis through Evolutionary Relationships.

RESULTS

Total DEs included C versus T, 469; C versus WSD, 525; C versus T+WSD, 549; and T versus T+WSD, 1,505. The majority of DEs mapped to the ontology pathways: heterotrimeric G-protein signaling pathways Gi alpha and Gs alpha (C vs. T), WNT signaling (C vs. WSD and T vs. T+WSD), and Huntington disease (C vs. T+WSD). A total of 2,171 DEs from eutopic endometrium were altered by the presence of stage 3 and 4 endometriosis lesions.

CONCLUSIONS

The present global transcriptomic analyses demonstrate that the greatest magnitude of changes occurred in contrasts of C and T versus T+WSD, adding to the evidence that these two insults have a synergistic effect on female physiology. These data also support the concept that prior alterations to the function of eutopic endometrium increase the risk for endometriosis.

Selective Progesterone Receptor Modulators-Mechanisms and Therapeutic Utility

Selective progesterone receptor modulators (SPRMs) are a new class of compounds developed to target the progesterone receptor (PR) with a mix of agonist and antagonist properties. These compounds have been introduced for the treatment of several gynecological conditions based on the critical role of progesterone in reproduction and reproductive tissues. In patients with uterine fibroids, mifepristone and ulipristal acetate have consistently demonstrated efficacy, and vilaprisan is currently under investigation, while studies of asoprisnil and telapristone were halted for safety concerns. Mifepristone demonstrated utility for the management of endometriosis, while data are limited regarding the efficacy of asoprisnil, ulipristal acetate, telapristone, and vilaprisan for this condition. Currently, none of the SPRMs have shown therapeutic success in treating endometrial cancer. Multiple SPRMs have been assessed for efficacy in treating PR-positive recurrent breast cancer, with in vivo studies suggesting a benefit of mifepristone, and multiple in vitro models suggesting the efficacy of ulipristal acetate and telapristone. Mifepristone, ulipristal acetate, vilaprisan, and asoprisnil effectively treated heavy menstrual bleeding (HBM) in patients with uterine fibroids, but limited data exist regarding the efficacy of SPRMs for HMB outside this context. A notable class effect of SPRMs are benign, PR modulator-associated endometrial changes (PAECs) due to the actions of the compounds on the endometrium. Both mifepristone and ulipristal acetate are effective for emergency contraception, and mifepristone was approved by the US Food and Drug Administration (FDA) in 2012 for the treatment of Cushing's syndrome due to its additional antiglucocorticoid effect. Based on current evidence, SPRMs show considerable promise for treatment of several gynecologic conditions.

Steroids receptors immunohistochemical expression in different sites of endometriosis

BACKGROUND

A better characterization of steroid intracrine pathways in endometriosis lesions may lead to a better understanding of the pathogenesis of the disease and insights on the mechanism of resistance to medical therapy. The study aims to evaluate the expression of steroid receptors in endometriosis lesions, including for the first-time androgen receptors, both in glandular and stromal tissue, and to describe the differences, in any, in receptor expression in the different subtypes.

BASIC PROCEDURES

This is a retrospective analysis of 76 specimens from 51 women, that underwent laparoscopic surgery for endometriosis at a tertiary hospital between 2015 and 2019. Immunohistochemical detections of estrogen, progesterone and androgen receptors positive cells was performed and the results described in terms of both density and intensity. The density and intensity scores were combined to obtain a final Histological Score (HS). Non-parametric Kruskal-Wallis test or Mann-Whitney U-test were used to compare continuous data, chi square test for categorical data.

MAIN FINDINGS

Estrogen receptor α expression was moderate/high in almost all specimens, regardless of the site. Samples from endometriomas presented lower progesterone receptor expression in the epithelium, compared to pelvic sites. Androgen receptor density was higher in stromal cells compared to epithelial cells and in pelvic sites compared to ovarian ones.

CONCLUSIONS

The roles of nuclear receptors in endometriosis, including differences in their expression, could help in defining the pathogenesis of the disease and in explaining different responsivity to therapies. The intracrine regulation of steroids plays a relevant role in the metabolic and inflammatory pathogenetic paths of endometriosis: if better understood, its manipulation could be a relevant therapeutic target for treatment.

Gonadotrophins modulate cell death-related genes expression in human endometrium

Background Gonadotrophins exert their functions by binding follicle-stimulating hormone receptor (FSHR) or luteinizing hormone and human chorionic gonadotropin receptor (LHCGR) present on endometrium. Within ovaries, FSH induces autophagy and apoptosis of granulosa cells leading to atresia of non-growing follicles, whereas hCG and LH have anti-apoptotic functions. Endometrial cells express functioning gonadotrophin receptors. The objective of this study was to analyze the effect of gonadotrophins on physiology and endometrial cells survival. Materials and methods Collected endometria were incubated for 48 or 72 h with 100 ng/mL of recombinant human FSH (rhFSH), recombinant human LH (rhLH) or highly purified hCG (HPhCG) alone or combined. Controls omitted gonadotrophins. The effect of gonadotrophins on cytochrome P450 family 11 subfamily A polypeptide 1 (CYP11A1), hypoxia inducible factor 1α (HIF1A), and cell-death-related genes expression was evaluated by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Immunohistochemistry for microtubule-associated proteins 1A/1B light chain 3B (MAP1LC3B) and apoptotic protease activating factor 1 (APAF-1) was performed. Results Gonadotrophins are able to modulate the endometrial cells survival. FSH induced autophagy and apoptosis by increasing the relative expression of MAP1LC3B and FAS receptor. In FSH-treated samples, expression of apoptosis marker APAF-1 was detected and co-localized on autophagic cells. hCG and LH does not modulate the expression of cell-death-related genes while the up-regulation of pro-proliferative epiregulin gene was observed. When combined with FSH, hCG and LH prevent autophagy and apoptosis FSH-induced. Conclusions Different gonadotrophins specifically affect endometrial cells viability differently: FSH promotes autophagy and apoptosis while LH and hCG alone or combined with rhFSH does not.

An assessment of the multifactorial profile of steroid-metabolizing enzymes and steroid receptors in the eutopic endometrium during moderate to severe ovarian endometriosis

BACKGROUND

Previous studies of expression profiles of major endometrial effectors of steroid physiology in endometriosis have yielded markedly conflicting conclusions, presumably because the relative effects of type of endometriosis, fertility history and menstrual cycle phases on the measured variables were not considered. In the present study, endometrial mRNA and protein levels of several effectors of steroid biosynthesis and action in patients with stage III-IV ovarian endometriosis (OE) with known fertility and menstrual cycle histories were compared with the levels in control endometrium to test this concept.

METHODS

Endometrial samples were collected from patients without endometriosis (n = 32) or OE stages III-IV (n = 52) with known fertility and cycle histories. qRT-PCR and immunoblotting experiments were performed to measure levels of NR5A1, STAR, CYP19A1, HSD17Bs, ESRs and PGR transcripts and proteins, respectively. Tissue concentrations of steroids (P4, T, E1 and E2) were measured using ELISAs.

RESULTS

The levels of expression of aromatase and ERβ were lower (P < 0.0001) and 17β-HSD1 (P < 0.0001) and PRA (P < 0.01) were higher in OE endometrium. Lower aromatase levels and higher 17β-HSD1 levels were detected in fertile (aromatase: P < 0.05; 17β-HSD1: P < 0.0001) and infertile (aromatase: P < 0.0001; 17β-HSD1: P < 0.0001) OE endometrium than in the matched control tissues. Both proliferative (PP) and secretory (SP) phase OE samples expressed aromatase (P < 0.0001) and ERβ (PP: P < 0.001; SP: P < 0.01) at lower levels and 17β-HSD1 (P < 0.0001) and PRA (PP: P < 0.01; SP: P < 0.0001) at higher levels than matched controls. Higher 17β-HSD1 (P < 0.01) and E2 (P < 0.05) levels and a lower (P < 0.01) PRB/PRA ratio was observed in infertile secretory phase OE endometrium than in control.

CONCLUSIONS

We report that dysregulated expression of 17β-HSD1 and PGR resulting in hyperestrogenism and progesterone resistance during the secretory phase of the menstrual cycle, rather than an anomaly in aromatase expression, was the hallmark of eutopic endometrium from infertile OE patients. Furthermore, the results provide proof of concept that the fertility and menstrual cycle histories exerted relatively different effects on steroid physiology in the endometrium from OE patients compared with the control subjects.

Rapid and structure-specific cellular uptake of selected steroids

Steroid hormones and their respective nuclear receptors are essential mediators in numerous physiologic and pathophysiologic processes, ranging from regulation of metabolism, immune function, and reproductive processes to the development of hormone-dependent cancers such as those of the breast and prostate. Because steroids must enter cells before activating nuclear receptors, understanding the mechanisms by which cellular uptake occurs is critical, yet a clear understanding of these mechanisms has been elusive. It is generally assumed that diffusion-driven uptake is similar across various steroids whereas an elevated cellular concentration is thought to reflect active uptake, but these assumptions have not been directly tested. Here we show that intact cells rapidly accumulate free steroids to markedly elevated concentrations. This effect varies widely depending on steroid structure; more lipophilic steroids reach more elevated concentrations. Strong preferences exist for 3β-OH, Δ5-steroids vs. 3-keto, Δ4-structural features and for progestogens vs. androgens. Surprisingly, steroid-structure-specific preferences do not require cell viability, implying a passive mechanism, and occur across cells derived from multiple tissue types. Physiologic relevance is suggested by structure-specific preferences in human prostate tissue compared with serum. On the other hand, the presence of serum proteins in vitro blocks much, but not all, of the passive accumulation, while still permitting a substantial amount of active accumulation for certain steroids. Our findings suggest that both passive and active uptake mechanisms make important contributions to the cellular steroid uptake process. The role of passive, lipophilicity-driven accumulation has previously been largely unappreciated, and its existence provides important context to studies on steroid transport and action both in vitro and in vivo.

Aldo-keto reductase 1C3-Assessment as a new target for the treatment of endometriosis

Endometriosis is a common gynecological disorder, which is treated surgically and/ or pharmacologically with an unmet clinical need for new therapeutics. A completed phase I trial and a recent phase II trial that investigated the steroidal aldo-keto reductase 1C3 (AKR1C3) inhibitor BAY1128688 in endometriosis patients prompted this critical assessment on the role of AKR1C3 in endometriosis. This review includes an introduction to endometriosis with emphasis on the roles of prostaglandins and progesterone in its pathophysiology. This is followed by an overview of the major enzymatic activities and physiological functions of AKR1C3 and of the data published to date on the expression of AKR1C3 in endometriosis at the mRNA and protein levels. The review concludes with the rationale for using AKR1C3 inhibitors, a discussion of the effects of AKR1C3 inhibition on the pathophysiology of endometriosis and a brief overview of other drugs under clinical investigation for this indication.

Local estrogen metabolism (intracrinology) in endometrial cancer: A systematic review

Endometrial cancer (EC) is the most common malignancy of the female gynaecological tract and increased exposure to estrogens is a risk factor. EC cells are able to produce estrogens locally using precursors like, among others, adrenal steroids present in the serum. This is referred to as local estrogen metabolism (or intracrinology) and consists of a complex network of multiple enzymes. Particular relevant to the final generation of active estrogens in endometrial cells are: steroid sulfatase (STS), estrogen sulfotransferase (SULT1E1), aromatase (CYP19A1), 17β-hydroxysteroid dehydrogenase (HSD17B) type 1 and type 2. During the last decades, a plethora of studies explored the level of these enzymes in EC but contrasting data were reported, which generated vigorous debate and controversies. Several reviews attempted at clarifying some of the debated issues, but published reviews are based on investigator-defined bibliography selection and not on systematic analysis. Therefore, we performed a systematic review of the literature reporting about the level of STS, SULT1E1, CYP19A1, HSD17B1 and HSD17B2 in EC. Additional intracrine enzymes and networks (e.g., HSD17Bs other than types 1 and 2, aldo-keto reductases, progesterone and androgen metabolism) were non-systematically reviewed as well.

Secreted frizzled-related protein 2 (SFRP2) expression promotes lesion proliferation via canonical WNT signaling and indicates lesion borders in extraovarian endometriosis

STUDY QUESTION

What is the role of SFRP2 in endometriosis?

SUMMARY ANSWER

SFRP2 acts as a canonical WNT/CTNNB1 signaling agonist in endometriosis, regulating endometriosis lesion growth and indicating endometriosis lesion borders together with CTNNB1 (also known as beta catenin).

WHAT IS KNOWN ALREADY

Endometriosis is a common, chronic disease that affects women of reproductive age, causing pain and infertility, and has significant economic impact on national health systems. Despite extensive research, the pathogenesis of endometriosis is poorly understood, and targeted medical treatments are lacking. WNT signaling is dysregulated in various human diseases, but its role in extraovarian endometriosis has not been fully elucidated.

STUDY DESIGN, SIZE, DURATION

We evaluated the significance of WNT signaling, and especially secreted frizzled-related protein 2 (SFRP2), in extraovarian endometriosis, including peritoneal and deep lesions. The study design was based on a cohort of clinical samples collected by laparoscopy or curettage and questionnaire data from healthy controls and endometriosis patients.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Global gene expression analysis in human endometrium (n = 104) and endometriosis (n = 177) specimens from 47 healthy controls and 103 endometriosis patients was followed by bioinformatics and supportive qPCR analyses. Immunohistochemistry, Western blotting, primary cell culture and siRNA knockdown approaches were used to validate the findings.

MAIN RESULTS AND THE ROLE OF CHANCE

Among the 220 WNT signaling and CTNNB1 target genes analysed, 184 genes showed differential expression in extraovarian endometriosis (P < 0.05) compared with endometrium tissue, including SFRP2 and CTNNB1. Menstrual cycle-dependent regulation of WNT genes observed in the endometrium was lost in endometriosis lesions, as shown by hierarchical clustering. Immunohistochemical analysis indicated that SFRP2 and CTNNB1 are novel endometriosis lesion border markers, complementing immunostaining for the known marker CD10 (also known as MME). SFRP2 and CTNNB1 localized similarly in both the epithelium and stroma of extraovarian endometriosis tissue, and interestingly, both also indicated an additional distant lesion border, suggesting that WNT signaling is altered in the endometriosis stroma beyond the primary border indicated by the known marker CD10. SFRP2 expression was positively associated with pain symptoms experienced by patients (P < 0.05), and functional loss of SFRP2 in extraovarian endometriosis primary cell cultures resulted in decreased cell proliferation (P < 0.05) associated with reduced CTNNB1 protein expression (P = 0.05).

LIMITATIONS REASONS FOR CAUTION

SFRP2 and CTNNB1 improved extraovarian endometriosis lesion border detection in a relatively small cohort (n = 20), although larger studies with different endometriosis subtypes in variable cycle phases and under hormonal medication are required.

WIDER IMPLICATIONS OF THE FINDINGS

The highly expressed SFRP2 and CTNNB1 improve endometriosis lesion border detection, which can have clinical implications for better visualization of endometriosis lesions over CD10. Furthermore, SFRP2 acts as a canonical WNT/CTNNB1 signaling agonist in endometriosis and positively regulates endometriosis lesion growth, suggesting that the WNT pathway may be an important therapeutic target for endometriosis.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the Academy of Finland and by Tekes: Finnish Funding Agency for Innovation. The authors have no conflict of interest to declare.

Endometrial Intracrinology: Oestrogens, Androgens and Endometrial Disorders

Peripheral tissue metabolism of steroids (intracrinology) is now accepted as a key way in which tissues, such as the endometrium, can utilise inactive steroids present in the blood to respond to local physiological demands and 'fine-tune' the activation or inhibition of steroid hormone receptor-dependent processes. Expression of enzymes that play a critical role in the activation and inactivation of bioactive oestrogens (E1, E2) and androgens (A4, T, DHT), as well as expression of steroid hormone receptors, has been detected in endometrial tissues and cells recovered during the menstrual cycle. There is robust evidence that increased expression of aromatase is important for creating a local microenvironment that can support a pregnancy. Measurement of intra-tissue concentrations of steroids using liquid chromatography⁻tandem mass spectrometry has been important in advancing our understanding of a role for androgens in the endometrium, acting both as active ligands for the androgen receptor and as substrates for oestrogen biosynthesis. The emergence of intracrinology, associated with disordered expression of key enzymes such as aromatase, in the aetiology of common women's health disorders such as endometriosis and endometrial cancer has prompted renewed interest in the development of drugs targeting these pathways, opening up new opportunities for targeted therapies and precision medicine.

Intracrine Regulation of Estrogen and Other Sex Steroid Levels in Endometrium and Non-gynecological Tissues; Pathology, Physiology, and Drug Discovery

Our understanding of the intracrine (or local) regulation of estrogen and other steroid synthesis and degradation expanded in the last decades, also thanks to recent technological advances in chromatography mass-spectrometry. Estrogen responsive tissues and organs are not passive receivers of the pool of steroids present in the blood but they can actively modify the intra-tissue steroid concentrations. This allows fine-tuning the exposure of responsive tissues and organs to estrogens and other steroids in order to best respond to the physiological needs of each specific organ. Deviations in such intracrine control can lead to unbalanced steroid hormone exposure and disturbances. Through a systematic bibliographic search on the expression of the intracrine enzymes in various tissues, this review gives an up-to-date view of the intracrine estrogen metabolisms, and to a lesser extent that of progestogens and androgens, in the lower female genital tract, including the physiological control of endometrial functions, receptivity, menopausal status and related pathological conditions. An overview of the intracrine regulation in extra gynecological tissues such as the lungs, gastrointestinal tract, brain, colon and bone is given. Current therapeutic approaches aimed at interfering with these metabolisms and future perspectives are discussed.

Intratumoral androgen levels are linked to TMPRSS2-ERG fusion in prostate cancer

Intratumoral androgen biosynthesis is one of the mechanisms involved in the progression of prostate cancer, and an important target for novel prostate cancer therapies. Using gas chromatography-tandem mass spectrometry and genome-wide RNA sequencing, we have analyzed androgen concentrations and androgen-regulated gene expression in cancerous and morphologically benign prostate tissue specimens and serum samples obtained from 48 primary prostate cancer patients. Intratumoral dihydrotestosterone (DHT) concentrations were significantly higher in the cancerous tissues compared to benign prostate (P < 0.001). The tissue/serum ratios of androgens were highly variable between the patients, indicating individual patterns of androgen metabolism and/or uptake of androgens within the prostate tissue. An unsupervised hierarchical clustering analysis of intratissue androgen concentrations indicated that transmembrane protease, serine 2/ETS-related gene (TMPRSS2-ERG)-positive patients have different androgen profiles compared to TMPRSS2-ERG-negative patients. TMPRSS2-ERG gene fusion status was also associated with an enhanced androgen-regulated gene expression, along with altered intratumoral androgen metabolism, demonstrated by reduced testosterone concentrations and increased DHT/testosterone ratios in TMPRSS2-ERG-positive tumors. TMPRSS2-ERG-positive and -negative prostate cancer specimens have distinct intratumoral androgen profiles, possibly due to activation of testosterone-independent DHT biosynthesis via the alternative pathway in TMPRSS2-ERG-positive tumors. Thus, patients with TMPRSS2-ERG-positive prostate cancer may benefit from novel inhibitors targeting the alternative DHT biosynthesis.

SULFATION PATHWAYS: Contribution of intracrine oestrogens to the aetiology of endometriosis

Endometriosis is an incurable hormone-dependent inflammatory disease that causes chronic pelvic pain and infertility characterized by implantation and growth of endometrial tissue outside the uterine cavity. Symptoms have a major impact on the quality of life of patients resulting in socioeconomic, physical and psychological burdens. Although the immune system and environmental factors may play a role in the aetiology of endometriosis, oestrogen dependency is still considered a hallmark of the disorder. The impact of oestrogens such as oestrone and particularly, oestradiol, on the endometrium or endometriotic lesions may be mediated by steroids originating from ovarian steroidogenesis or local intra-tissue production (intracrinology) dependent upon the expression and activity of enzymes that regulate oestrogen biosynthesis and metabolism. Two key pathways have been implicated: while there is contradictory data on the participation of the aromatase enzyme (encoded by CYP19A1), there is increasing evidence that the steroid sulphatase pathway plays a role in both the aetiology and pathology of endometriosis. In this review, we consider the evidence related to the pathways leading to oestrogen accumulation in endometriotic lesions and how this might inform the development of new therapeutic strategies to treat endometriosis without causing the undesirable side effects of current regimes that suppress ovarian hormone production.

Evidence for expression and functionality of FSH and LH/hCG receptors in human endometrium

PURPOSE

Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) mediate intracellular functions by binding their specific protein G-coupled gonadotrophin receptor, respectively FSH receptor (FSHR) and LH/choriogonadotrophin receptor (LHCGR). Whereas the expression of FSHR and LHCGR in mammals was considered gonad-specific and cell-specific, studies identified gonadotrophin receptors in human female extragonadal reproductive tissues. This study aims to demonstrate that gonadotrophin receptors are expressed in endometrium and mediates intracellular functions.

METHODS

Collected endometria (n = 12) from healthy patients (mean age of 36 ± 6) were primary cultured for 24 h. The presence of gonadotrophin receptors was evaluated by RT-PCR followed by the sequencing of the resulted amplicons and by immunohistochemistry in original samples. Endometrial primary cultures were treated with increasing concentration (range 0-100 ng/ml) of either recombinant human LH (rhLH) or recombinant human FSH (rhFSH). Endometria controls had gonadotrophin replaced by the same volume of the culture medium. In gonadotrophin-treated samples, it was evaluated the intracellular cyclic adenosine monophosphate (cAMP) content by enzymatic immunoassay and the expression of steroidogenic genes by reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR).

RESULTS

The sequencing of the RT-PCR amplicons confirmed the presence of both gonadotrophin receptors and immunohistochemistry localized them on the membrane of endometrial glands cells throughout the glandular epithelium. The gonadotrophin-receptor complex was able to increase the intracellular cAMP in a dose-response and time-course manner and to induce steroidogenic genes expression.

CONCLUSION

This study demonstrates that both gonadotrophin receptors are expressed along the glandular epithelium of endometria and they mediate the effects of gonadotrophins on intracellular functions.

Androgen-induced alterations in endometrial proteins crucial in recurrent miscarriages

High androgen level impairs endometrial receptivity in women experiences the recurrent miscarriage. The mechanism of androgen actions on endometrium is still uncertain. We hypothesized that androgen has a direct effect on the endometrium in women with recurrent miscarriage. In the present study, we assess the impact of androgen (A₂) at high concentration (10^–7 M) on Ishikawa cells compared with the physiological concentration of androgen (10^–9 M). To go into deeper analysis, we use global stable isotopes labeled profiling tactic using iTRAQ reagents, followed by 2D LC-MS/MS. We determine 175 non-redundant proteins, and 18 of these were quantified. The analysis of differentially expressed proteins (DEPs) identified 8 up-regulated proteins and 10 down-regulated in the high androgen group. These DEPs were examined by ingenuity pathway (IPA) analysis and established that these proteins might play vital roles in recurrent miscarriage and endometrium receptivity. In addition, proteins cyclin-dependent kinase inhibitor 2a (CDKN2a), endothelial protein C receptor (EPCR), armadillo repeat for velocardiofacial (ARVCF) were independently confirmed using western blot. Knockdown of CDKN2a significantly decreased the expression level of CDKN2a protein in ishikawa cells, and decreased migration (p < 0.01), invasion (p < 0.05), proliferation (p < 0.05), and the rate of Jar spheroid attachment (p < 0.05) to Ishikawa cell monolayer. The present results suggest that androgen at high concentration could alter the expression levels of proteins related to endometrium development and embryo implantation, which might be a cause of the impaired endometrial receptivity and miscarriage.

Androgens and endometrium: New insights and new targets

Androgens are synthesised in both the ovary and adrenals in women and play an important role in the regulation of female fertility, as well as in the aetiology of disorders such as polycystic ovarian syndrome, endometriosis and endometrial cancer. The endometrium is an androgen target tissue and the impact of AR-mediated effects has been studied using human endometrial tissue samples and rodent models. In this review we highlight recent evidence that endometrial androgen biosynthesis and intracrine action is important in preparation of a tissue microenvironment that can support implantation and establishment of pregnancy. The impact of androgens on endometrial cell proliferation, in repair of the endometrial wound at the time of menstruation and in endometrial disorders is discussed. Future directions for research focused on AR function as a therapeutic target are considered.

Deleting the mouse Hsd17b1 gene results in a hypomorphic Naglu allele and a phenotype mimicking a lysosomal storage disease

HSD17B1 is a steroid metabolising enzyme. We have previously generated knockout mice that had the entire coding region of Hsd17b1 replaced with lacZ-neo cassette (Hsd17b1-LacZ/Neo mice). This resulted in a 90% reduction of HSD17B1 activity, associated with severe subfertility in the knockout females. The present study indicates that Hsd17b1-LacZ/Neo male mice have a metabolic phenotype, including reduced adipose mass, increased lean mass and lipid accumulation in the liver. During the characterisation of this metabolic phenotype, it became evident that the expression of the Naglu gene, located closely upstream of Hsd17b1, was severely reduced in all tissues analysed. Similar results were obtained from Hsd17b1-LacZ mice after removing the neo cassette from the locus or by crossing the Hsd17b1-LacZ/Neo mice with transgenic mice constitutively expressing human HSD17B1. The deficiency of Naglu caused the accumulation of glycosaminoglycans in all studied mouse models lacking the Hsd17b1 gene. The metabolic phenotypes of the Hsd17b1 knockout mouse models were recapitulated in Naglu knockout mice. Based on the data we propose that the Hsd17b1 gene includes a regulatory element controlling Naglu expression and the metabolic phenotype in mice lacking the Hsd17b1 genomic region is caused by the reduced expression of Naglu rather than the lack of Hsd17b1.

Is cytochrome P450 3A4 regulated by menstrual cycle hormones in control endometrium and endometriosis?

The estrogen-metabolizing activities of cytochrome P450 (CYP) enzymes have been implicated in endometriosis. However, their regulation in various sources of endometrial tissue under different hormonal conditions has not been clarified. Our objective was to study the hormone regulation of a specific CYP enzyme, namely CYP3A4, in control (n = 15) and endometriosis patients (n = 42). To this end, we evaluated mRNA expression (using real-time PCR) of CYP3A4 in tissue samples classified according to the phase of menstrual cycle at which they were obtained as confirmed by the related circulating hormone levels. Protein expression was also evaluated by Western Blot. In order to further investigate the hormonal regulation of CYP3A4, stromal cells from ovarian endometriotic lesions were cultured with the prevailing hormones of the distinct phases of the menstrual cycle. We observed that all control and endometriosis tissues express CYP3A4. Nevertheless, changes in CYP3A4 gene expression related to cycle phase were only seen in the control eutopic endometrium and not in samples from endometriosis patients, with an increase in the luteal phase. Stromal cells isolated from ovarian endometriotic lesions expressed CYP3A4 and their exposure to luteal phase-mimicking hormones (estradiol + progesterone) reduced CYP3A4 mRNA in parallel with a diminished expression of the corresponding receptors, estrogen receptor alpha and progesterone receptor. Our findings suggest that steroid hormones are able to regulate CYP3A4 mRNA expression, although the circulating levels of these hormones can only regulate control endometrium and not endometriosis tissues, probably because of dysregulated local steroid concentration in these latter samples.

Regulation of androgen action during establishment of pregnancy

During the establishment of pregnancy, the ovarian-derived hormones progesterone and oestradiol regulate remodelling of the endometrium to promote an environment that is able to support and maintain a successful pregnancy. Decidualisation is characterised by differentiation of endometrial stromal cells that secrete growth factors and cytokines that regulate vascular remodelling and immune cell influx. This differentiation process is critical for reproduction, and inadequate decidualisation is implicated in the aetiology of pregnancy disorders such as foetal growth restriction and preeclampsia. In contrast to progesterone and oestradiol, the role of androgens in regulating endometrial function is poorly understood. Androgen receptors are expressed in the endometrium, and androgens are reported to regulate both the transcriptome and the secretome of endometrial stromal cells. In androgen-target tissues, circulating precursors are activated to mediate local effects, and recent studies report that steroid concentrations detected in endometrial tissue are distinct to those detected in the peripheral circulation. New evidence suggests that decidualisation results in dynamic changes in the expression of androgen biosynthetic enzymes, highlighting a role for pre-receptor regulation of androgen action during the establishment of pregnancy. These results suggest that such enzymes could be future therapeutic targets for the treatment of infertility associated with endometrial dysfunction. In conclusion, these data support the hypothesis that androgens play a beneficial role in regulating the establishment and maintenance of pregnancy. Future studies should be focussed on investigating the safety and efficacy of androgen supplementation with the potential for utilisation of novel therapeutics, such as selective androgen receptor modulators, to improve reproductive outcomes in women.

Androgen action in female reproductive physiology

PURPOSE OF REVIEW

In the last decade, it has been proven that androgens acting via the androgen receptor (AR) play an important role in the regulation of female reproductive function. However, the specific site of action and the precise pathways involved remain to be fully elucidated. This review aims to combine findings from emerging basic research to provide new insights into the roles of AR-mediated actions, and the mechanisms involved, in normal ovarian, uterine, and mammary gland function.

RECENT FINDINGS

Our understanding of the specific roles of androgens in females has been hindered as females with complete androgen insensitivity cannot be generated by natural breeding, and interpretation of results from pharmacological studies has led to confusion as some androgens can be converted into estrogens, which can mediate actions via estrogen receptors. However, with the creation of global and cell-specific female AR knockout mouse models by Cre-LoxP technology, and the use of aromatizable and nonaromatizable androgens, novel roles for androgens in the regulation of female reproductive physiology have been revealed.

SUMMARY

AR-mediated mechanisms play important roles in mediating normal ovarian, uterine, and mammary gland function and there is hope that further elucidation of the role of androgens in female reproductive physiology may translate into the development of novel, evidence-based, and targeted treatment for androgen-associated conditions.

Increased steroid hormone dehydroepiandrosterone and pregnenolone levels in post-mortem brain samples of alcoholics

Intra-tissue levels of steroid hormones (e.g., dehydroepiandrosterone [DHEA], pregnenolone [PREGN], and testosterone [T]) may influence the pathological changes seen in neurotransmitter systems of alcoholic brains. Our aim was to compare levels of these steroid hormones between the post-mortem brain samples of alcoholics and non-alcoholic controls. We studied steroid levels with quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) in post-mortem brain samples of alcoholics (N = 14) and non-alcoholic controls (N = 10). Significant differences were observed between study groups in DHEA and PREGN levels (p values 0.0056 and 0.019, respectively), but not in T levels. Differences between the study groups were most prominent in the nucleus accumbens (NAC), anterior cingulate cortex (ACC), and anterior insula (AINS). DHEA levels were increased in most alcoholic subjects compared to controls. However, only a subgroup of alcoholics showed increased PREGN levels. Negative Spearman correlations between tissue levels of PREGN and previous reports of [(3)H]naloxone binding to μ-opioid receptors were observed in the AINS, ACC, NAC, and frontal cortex (R values between -0.6 and -0.8; p values ≤ 0.002), suggesting an association between the opioid system and brain PREGN levels. Although preliminary, and from relatively small diagnostic groups, these results show significantly increased levels of DHEA and PREGN in the brains of alcoholics, and could be associated with the pathology of alcoholism.

A Role for Androgens in Epithelial Proliferation and Formation of Glands in the Mouse Uterus

The endometrium consists of stromal and epithelial compartments (luminal and glandular) with distinct functions in the regulation of uterine homeostasis. Ovarian sex steroids, namely 17β-estradiol and progesterone, play essential roles in modulating uterine cell proliferation, stromal-epithelial cross-talk and differentiation in preparation for pregnancy. The effect of androgens on uterine function remains poorly understood. The current study investigated the effect of the non-aromatizable androgen dihydrotestosterone (DHT) on mouse endometrial function. Ovx female mice were given a single sc injection (short treatment) or 7 daily injections (long treatment) of vehicle alone (5% ethanol, 0.4% methylcellulose) or vehicle with the addition of 0.2 mg DHT (n=8/group) and a single injection of bromodeoxyuridine 2 hours prior to tissue recovery. Treatment with DHT increased uterine weight, the area of the endometrial compartment and immunoexpression of the androgen receptor in the luminal and glandular epithelium. Treatment-dependent proliferation of epithelial cells was identified by immunostaining for MKi67 and bromodeoxyuridine. Real-time PCR identified significant DHT-dependent changes in the concentrations of mRNAs encoded by genes implicated in the regulation of the cell cycle (Wee1, Ccnd1, Rb1) and stromal-epithelial interactions (Wnt4, Wnt5a, Wnt7a, Cdh1, Vcl, Igf1, Prl8, Prlr) as well as a striking effect on the number of endometrial glands. This study has revealed a novel role for androgens in regulating uterine function with an effect on the glandular compartment of the endometrium. This previously unrecognized role for androgens has implications for our understanding of the role of androgens in regulation of endometrial function and fertility in women.

Human Endometrial Fibroblasts Derived from Mesenchymal Progenitors Inherit Progesterone Resistance and Acquire an Inflammatory Phenotype in the Endometrial Niche in Endometriosis

Human endometrium undergoes cyclic regeneration involving stem/progenitor cells, but the role of resident endometrial mesenchymal stem cells (eMSC) as progenitors of endometrial stromal fibroblasts (eSF) has not been definitively demonstrated. In endometriosis, eSF display progesterone (P4) resistance with impaired decidualization in vivo and in vitro. To investigate eMSC as precursors of eSF and whether endometriosis P4 resistance is inherited from eMSC, we analyzed transcriptomes of eutopic endometrium eMSC and eSF isolated by fluorescence-activated cell sorting (FACS) from endometriosis (eMSCendo, eSFendo) and controls (eMSCcontrol, eSFcontrol) and their derived primary cultures. Differentially expressed lineage-associated genes (LG) of FACS-isolated eMSC and eSF were largely conserved in endometriosis. In culture, eSFcontrol maintained in vitro expression of a subset of eSF LG and decidualized in vitro with P4 The eMSCcontrol cultures differentiated in vitro to eSF lineage, down-regulating eMSC LG and up-regulating eSF LG, showing minimal transcriptome differences versus eSFcontrol cultures and decidualizing in vitro. Cultured eSFendo displayed less in vitro LG stability and did not decidualize in vitro. In vitro, eMSCendo differentiated to eSF lineage but showed more differentially expressed genes versus eSFendo cultures, and did not decidualize in vitro, demonstrating P4 resistance inherited from eMSCendo Compared to controls, cultures from tissue-derived eSFendo uniquely had a pro-inflammatory phenotype not present in eMSCendo differentiated to eSF in vitro, suggesting divergent niche effects for in vivo versus in vitro lineage differentiation. These findings substantiate eMSC as progenitors of eSF and reveal eSF in endometriosis as having P4 resistance inherited from eMSC and a pro-inflammatory phenotype acquired within the endometrial niche.

Effects of steroid hormone on estrogen sulfotransferase and on steroid sulfatase expression in endometriosis tissue and stromal cells

Endometriosis is an estrogen-dependent disease that afflicts about 10% of women in their reproductive age, causing severe pain and infertility. The potential roles of female steroid hormones in modulating key estrogen-metabolizing enzymes, steroid sulfatase (STS) and estrogen sulfotransferase (SULT1E1), were investigated. The expression of STS and SULT1E1 mRNA in biopsy samples (n=78) of superficial and deep endometriotic lesions, eutopic endometrium of women with endometriosis and endometrium from control patients were compared according to the menstrual cycle phase. Increased STS gene expression was detected in superficial and deep-infiltrating lesions and a reduced SULT1E1 expression was also observed in the eutopic endometrium relative to the superficial lesions. Additionally, a significantly positive correlation was detected between STS and SULT1E1 mRNA expression levels in biopsy specimens collected from the endometriosis patients, and not in control individuals. The actions of female steroid hormones on SULT1E1 and STS expression were evidenced in endometriosis, revealed by increased expression levels in the luteal phase of the cycle. There was an increased STS expression in primary eutopic and ectopic endometrial stromal cells treated with estradiol and progesterone (representative of the luteal phase, n=3). Although an increased STS mRNA expression was observed in hormone-induced endometrial stromal cells in vitro, no difference could be detected between the hormone treatment groups in estradiol formation from estradiol sulfate measured by LC-MS-MS. Interestingly, a greater expression of STS was observed in stromal cells from eutopic endometrium with an agreement in estradiol formation originated from estradiol sulfate. The differential regulation of STS and SULT1E1 could provide insights for novel studies of the therapeutic use of STS inhibitors.

Increased expression of CYP1A1 and CYP1B1 in ovarian/peritoneal endometriotic lesions

Endometriosis is an estrogen-dependent disease affecting up to 10% of all premenopausal women. There is evidence that different endometriosis sites show distinct local estrogen concentration, which, in turn, might be due to a unique local estrogen metabolism. We aimed to investigate whether there was a site-specific regulation of selected enzymes responsible for the oxidative metabolism of estrogens in biopsy samples and endometrial and endometriotic stromal cells. Cytochrome P450 (CYP) 1A1 and CYP1B1 mRNA and protein expressions in deep-infiltrating (rectal, retossigmoidal, and uterossacral) lesions, superficial (ovarian and peritoneal) lesions, and eutopic and healthy (control) endometrium were evaluated by real-time PCR and western blot. Using a cross-sectional study design with 58 premenopausal women who were not under hormonal treatment, we were able to identify an overall increased CYP1A1 and CYP1B1 mRNA expression in superficial lesions compared with the healthy endometrium. CYP1A1 mRNA expression in superficial lesions was also greater than in the eutopic endometrium. Interestingly, we found a similar pattern of CYP1A1 and CYP1B1 expression in in vitro stromal cells isolated from ovarian lesions (n=3) when compared with stromal cells isolated from either rectum lesions or eutopic endometrium. In contradiction, there was an increased half-life of estradiol (measured by HPLC-MS-MS) in ovarian endometriotic stromal cells compared with paired eutopic stromal endometrial cells. Our results indicate that there is a site-dependent regulation of CYP1A1 and CYP1B1 in ovarian/peritoneal lesions and ovarian endometriotic stromal cells, whereas a slower metabolism is taking place in these cells.

Genome-wide Long Non-coding RNA Analysis Identified Circulating LncRNAs as Novel Non-invasive Diagnostic Biomarkers for Gynecological Disease

Increasing evidence indicates that long non-coding RNAs (lncRNAs) play important roles in human diseases. This study aimed to investigate the tissue and serum lncRNAs that are differentially expressed between patients with endometriosis, a gynecological disease, to evaluate the potential of these lncRNAs as non-invasive markers for the disease. The differentially expressed lncRNAs as competing endogenous RNAs (ceRNAs) were also analyzed to predict their functions in disease development. Genome-wide profiling of lncRNA expression patterns revealed that many lncRNAs were abnormally expressed between sera and tissuesof the patient samples. A set of aberrant differentially expressed lncRNAs were further validated in a validation cohort of 110 serum and 24 tissue samples. Functional analysis predicted that differentially expressed lncRNAs may participate in disease development through crosstalk between the ceRNAs of miRNAs and may be involved in a range of cellular pathways including steroid or hormone responses. We also found a unique set of lncRNAs that were associated with disease severity and progression, and their diagnostic values were also investigated. Our study demonstrated that lncRNAs could potentially serve as non-invasive biomarkers for the diagnosis of endometriosis and as important regulators in the progression of this disease.

Intracrine Androgens Enhance Decidualization and Modulate Expression of Human Endometrial Receptivity Genes

The endometrium is a complex, steroid-dependent tissue that undergoes dynamic cyclical remodelling. Transformation of stromal fibroblasts (ESC) into specialised secretory cells (decidualization) is fundamental to the establishment of a receptive endometrial microenvironment which can support and maintain pregnancy. Androgen receptors (AR) are present in ESC; in other tissues local metabolism of ovarian and adrenal-derived androgens regulate AR-dependent gene expression. We hypothesised that altered expression/activity of androgen biosynthetic enzymes would regulate tissue availability of bioactive androgens and the process of decidualization. Primary human ESC were treated in vitro for 1–8 days with progesterone and cAMP (decidualized) in the presence or absence of the AR antagonist flutamide. Time and treatment-dependent changes in genes essential for a) intra-tissue biosynthesis of androgens (5α-reductase/SRD5A1, aldo-keto reductase family 1 member C3/AKR1C3), b) establishment of endometrial decidualization (IGFBP1, prolactin) and c) endometrial receptivity (SPP1, MAOA, EDNRB) were measured. Decidualization of ESC resulted in significant time-dependent changes in expression of AKR1C3 and SRD5A1 and secretion of T/DHT. Addition of flutamide significantly reduced secretion of IGFBP1 and prolactin and altered the expression of endometrial receptivity markers. Intracrine biosynthesis of endometrial androgens during decidualization may play a key role in endometrial receptivity and offer a novel target for fertility treatment.

Increased dose single-agent gemcitabine in platinum-taxane resistant metastatic ovarian cancer

CONCLUSION

In platinum–taxane resistant epithelial ovarian cancer (EOC), we aimed to determine the effectiveness.

PATIENTS AND METHODS

Between 2004 and 2013, patients afflicted with platinum–taxane resistant EOC and who were administered a 30-minute i.v. infusion of single-agent gemcitabine at a dose of 1,250 mg/m2 on the 1st, 8th and 15th days, every 28 days, were examined retrospectively.

RESULTS

Twenty-six patients with platinum–taxane resistant EOC were included in the study. The overall survival (OS) was 48 months. The median survival after becoming platinum–taxane resistant was 16 months for the study population. Median time to progression (TTP) and median survival after becoming platinum–taxane resistant for patients who received second-line treatment were 3.3 months and 16 months, respectively; for patients who received third-line treatment with gemcitabine, these were 3.7 months and 19 months, respectively. Administration of gemcitabine as second- and third-line chemotherapy in platinum–taxane resistant EOC, provides similar TTP and OS outcomes (p = 0.4, p = 0.9) with a similar response and toxicity rate.

CONCLUSIONS

Second- and third-line gemcitabine at a dose of 1,250 mg/m2 on days 1, 8 and 15 every 28 days as a 30-minute i.v. infusion in platinum–taxane resistant EOC is an effective treatment option with a tolerable and manageable toxicity.