Androgen receptors are acquired by healthy postmenopausal endometrial epithelium and their subsequent loss in endometrial cancer is associated with poor survival

Multi-Steroid Profiling and Machine Learning Reveal Androgens as Candidate Biomarkers for Endometrial Cancer Diagnosis: A Case-Control Study

OBJECTIVE

To evaluate the diagnostic and prognostic potential of preoperative serum steroid levels in endometrial cancer (EC) alone and in combination with clinical parameters and biomarkers CA-125 and HE4.

METHODS

This single-center observational study included 62 patients with EC and 70 controls with benign uterine conditions who underwent surgery between June 2012 and February 2020. Preoperative serum levels of classic androgens, 11-oxyandrogens, glucocorticoids and mineralocorticoids were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Machine learning was used to assess their diagnostic and prognostic value alone and combined with clinical parameters and tumor biomarkers.

RESULTS

Patients with EC had significantly higher serum levels of classic androgens (androstenedione, testosterone), 11-oxyandrogens (11β-hydroxy-androstenedione, 11β-hydroxy-testosterone) and glucocorticoids (17α-hydroxy-progesterone, 11-deoxycortisol) compared to controls. While individual steroids had limited diagnostic value, a multivariate model including classic androgens, CA-125, HE4, BMI and parity achieved an AUC 0.87, 79.1% sensitivity and 74.7% specificity in distinguishing EC from benign uterine condition. This model outperformed our previously published model based on CA-125, HE4 and BMI (AUC: 0.81, p < 0.0001). Prognostically, HE4 was the strongest marker for lymphovascular space invasion (LVSI) (AUC: 0.79) and deep myometrial invasion (MI) (AUC: 0.71). Among steroids, androstenedione was the most predictive of LVSI (AUC: 0.67), while 11β-hydroxy-testosterone was the strongest predictor of deep MI (AUC: 0.64).

CONCLUSIONS

Patients with EC exhibit distinct steroid hormone profiles. While steroids alone offer modest diagnostic and prognostic value, integrating them into multivariate models improves diagnostic accuracy.

The role of the Androgen Receptor (AR) in endometrial cancer aggressiveness: Correlation with other prognostic markers and therapeutic implications. A retrospective observational study

Endometrial carcinoma (EC) is the most common gynecological malignancy, with increasing incidence linked to rising risk factors. This retrospective observational study investigates the role of the Androgen Receptor (AR) in EC aggressiveness, its correlation with other prognostic markers, and its potential therapeutic implications. A total of 143 cases of EC treated with hysterectomy were analyzed for AR expression and its association with clinicopathological and molecular markers, including estrogen receptor (ER), progesterone receptor (PR), Ki-67, p53, β-catenin, E-cadherin, Bcl-2, Cyclin D1, and mismatch repair (MMR) status. AR expression was significantly higher in low-grade endometrioid carcinoma (LGEC) compared to high-grade endometrioid carcinoma (HGEC) and other high-risk histologies (p = 0.015), suggesting a role in less aggressive tumor phenotypes. AR strongly correlated with ER and PR (p < 0.0001), indicating shared regulatory pathways. A borderline association with tumor-infiltrating lymphocytes (TILs) suggests a potential role in immune response. However, AR expression did not significantly correlate with markers of proliferation (Ki-67) or tumor suppression (p53), nor with β-catenin, E-cadherin, Bcl-2, Cyclin D1, or MMR status. These findings support AR as a prognostic marker in hormone-responsive EC subtypes and suggest that AR-targeted therapies could be beneficial, particularly in ER/PR-negative tumors. The study highlights the potential integration of AR status into molecular profiling, aiding in personalized treatment strategies for improved patient outcomes in EC management.

Androgen receptor signalling in non-prostatic malignancies: challenges and opportunities

The androgen receptor (AR) signalling pathway has been intensively studied in the context of prostate cancer, where androgen deprivation therapy is part of the standard of care for metastatic disease. By contrast, fewer studies have investigated the impact and translational potential of targeting AR in other cancer types where it is also expressed and functional. In this Review, we discuss the current understanding of AR in non-prostatic cancer types and summarize ongoing AR-directed clinical trials. While different androgen levels contribute to sexual dimorphism in cancer, targeting the AR system could benefit both sexes and help overcome resistance to targeted therapies. However, a bimodal function of AR signalling, which suppresses stromal changes associated with the early stages of cancer development, also needs to be considered. Future research is necessary to scrutinize cellular and molecular mechanisms of action of AR in cancer cells and the tumour microenvironment, to develop selective modulators of AR activity, and to identify patients with non-prostatic cancer who might benefit from targeting this pathway. AR-directed manipulation of host immune cells may offer a promising therapeutic approach for many types of cancers.

Hormone receptor profile of ectopic and eutopic endometrium in adenomyosis: a systematic review

STUDY QUESTION

What is the hormone receptor profile of adenomyosis lesions in comparison to correctly located endometrium?

SUMMARY ANSWER

Adenomyosis lesions exhibit increased oestrogen receptor (ER) expression compared to the eutopic endometrium; there are conflicting results regarding progesterone receptor (PR) expression and a lack of studies on androgen receptor (AR) expression.

WHAT IS KNOWN ALREADY

Adenomyosis lesions express hormone receptors indicating an influence from ovarian steroid hormones. However, hormone treatments are often ineffective in controlling adenomyosis symptoms, which suggests alternate hormonal responses and, potentially, a distinct hormone receptor expression profile within adenomyosis lesions compared to the eutopic endometrium.

STUDY DESIGN SIZE DURATION

This systematic review with a thematic analysis retrieved studies from the PubMed, Ovid Medline, Embase, Scopus, and Cochrane Library databases, and searches were conducted from inception through to May 2024. Human studies were included and identified using a combination of exploded MeSH terms ('adenomyosis') and free-text search terms ('oestrogen receptor', 'progesterone receptor', 'androgen receptor', 'hormone receptor').

PARTICIPANTS/MATERIALS SETTING METHODS

This review was reported in accordance with the PRISMA guidelines. All studies reporting original data concerning hormone receptors in adenomyosis lesions compared to eutopic endometrium in adenomyosis were included. Studies that did not report original data or provide a review of the field were excluded. Bias analysis was completed for each study using the Newcastle-Ottawa scoring system.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 1905 studies identified, which were screened to include 12 studies that met the eligibility criteria, including 11 proteomic studies and one transcriptional study, with a total of 555 individual participants. ER expression was consistently increased in adenomyosis lesions compared to the eutopic endometrium, specifically in the secretory phase. When endometrial subregion was considered, this difference was specific to the endometrial functionalis only. When different isoforms were considered, this increase in ER expression was specific to ERα rather than ERβ. There were conflicting results on PR expression, with most studies showing no significant difference or reduced levels in adenomyosis lesions compared to the eutopic endometrium. There is a paucity of data on AR expression in adenomyosis lesions, with only one study of small sample size included.

LIMITATIONS REASONS FOR CAUTION

A high risk of bias arose from studies grouping endometrial samples across different menstrual cycle phases for analysis. The coexistence of gynecological conditions like endometriosis may also confound the hormone receptor profile of the eutopic endometrium. Most studies employing immunostaining did not comment on region-specific differences in the endometrium. Given the well-documented cyclical variations in hormone receptor expression within the endometrium, the need for more attention to region-specific differences represents a notable limitation in the current body of literature.

WIDER IMPLICATIONS OF THE FINDINGS

The systematic review highlights oestrogen dominance through elevated ERα levels in adenomyosis lesions, which agrees with the literature suggesting local hyper-oestrogenism in adenomyosis lesions. Heterogeneity in menstrual cycle timing and lack of endometrial region specificity prevent conclusions on progesterone resistance within adenomyosis lesions in this study. Future investigations should minimize the bias through well-defined cohorts, leading to robust exploration of hormone receptor profiles in adenomyosis lesions to identify therapeutic targets and deepen our understanding of adenomyosis pathogenesis.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by Wellbeing of Women Research Project grants RG1073 and RG2137 (D.K.H.), a Wellbeing of Women Entry-Level Scholarship ELS706 and a Medical Research Council grant MR/V007238/1 (A.M. and D.K.H.), as well as the University of Liverpool (L.T.). There are no conflicts of interest.

HROPEN-24-0294R2

The review protocol was published in the PROSPERO Register of Systematic Reviews on 27 September 2023, registration number CRD4202346.

Functional, patient-derived 3D tri-culture models of the uterine wall in a microfluidic array

STUDY QUESTION

Can a functional in vitro model, containing the main cellular components of the uterine wall, be generated from cells derived from patient tissues?

SUMMARY ANSWER

We present a three-dimensional (3D) physiologically relevant, organ-on-a-chip model of the uterine wall containing primary endometrial and myometrial cellular participants, generated from human uterine tissue.

WHAT IS KNOWN ALREADY

As a highly dynamic reproductive organ, the human uterus plays fundamental physiological roles in menstruation and childbirth. The endometrial-myometrial junction (EMJ) defines the interface between the inner mucosal layer (endometrium) and outer smooth muscle zone (myometrium) that comprises the uterine wall. The EMJ is implicit in several uterine pathologies of unknown aetiology, including adenomyosis and abnormally invasive placenta; however, despite this, no patient-derived in vitro models of the uterine wall containing all EMJ participants currently exist.

STUDY DESIGN, SIZE, DURATION

We employed microfluidic technology to characterize multiple miniaturized models of the uterine wall. Protocols were tested that included variations in the seeding order of endometrial and myometrial fractions, and the addition of a low viscosity extracellular matrix to influence cell behaviour. Ultimately, functional hormone responses of patient-derived uterine wall models were assessed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Endometrial (n = 9) and myometrial biopsies (n = 4) were enzymatically dissociated to create epithelial, stromal and myometrial cellular fractions. Cell suspensions were seeded into non-adhesive poly(dimethylsiloxane) microfluidic devices containing 5 × 5 microwell arrays. The fate of individual cell types was monitored in real-time using fluorescent tracers, and cell phenotype was characterized by immunocytochemistry. Model functionality was assessed by measuring Ca2+ responses to agonist stimulation, and both insulin-like growth factor binding protein 1 (IGFBP-1) and osteopontin secretion in response to hormone stimulation.

MAIN RESULTS AND THE ROLE OF CHANCE

When subjected to microfluidic culture in isolation, endometrial stromal cells and smooth muscle myocytes formed compact spheroids, whilst epithelial cells produced diffuse aggregates. Tri-cultures were established by sequential seeding of individual or combined cell fractions at various ratios. Regardless of the protocol, epithelial cells localized to the outer periphery of tri-culture spheroids, which varied in morphology across the protocols. Incorporation of 5% [v/v] Matrigel® improved the reproducibility of 3D aggregates which exhibited robust self-assembly of a stromal/smooth muscle core encased in epithelium. Exposure of tri-cultures to oestradiol, medroxyprogesterone acetate and cyclic adenosine monophosphate (cAMP) increased secretion of IGFBP-1, which indicates stromal decidualization, and enhanced epithelial cell osteopontin secretion. Stimulation with endothelin-1 induced Ca2+ signalling in myocytes.

LIMITATIONS, REASONS FOR CAUTION

Endometrial and myometrial tissue was collected from relatively few donors. Myometrial tissue was collected from pregnant donors, which may have influenced the myocyte phenotype. Furthermore, endometrial tissue sampling was from women not having a hysterectomy, thus may not include the deeper basalis region, which may limit the physiological mimicry of the final models.

WIDER IMPLICATIONS OF THE FINDINGS

Our novel approach to modelling the uterine wall in 3D captures all of the main cell types in a medium-throughput system, enabling the screening of hundreds of cultures in parallel from a single biopsy. This system shows great promise for examining the cellular interplay between physiological cues and EMJ pathologies, such as the impact of uterine peristalsis and cyclical hormones on the pathogenesis of adenomyosis.

STUDY FUNDING/COMPETING INTEREST(S)

C.B. was supported by an Organ-on-a-Chip Technologies Network Pump Priming Project grant. C.J.H. was supported by a Wellbeing of Women project grant (RG2137), SRI/Bayer and Wellcome Trust IFFS3. D.K.H. was supported by a Wellbeing of Women project grant (RG2137) and MRC clinical research training fellowship (MR/V007238/1). M.Z. is Director and Co-Founder of ScreenIn3D Limited. The other authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Pre-receptor regulation of 11-oxyandrogens differs between normal and cancerous endometrium and across endometrial cancer grades and molecular subtypes

Background

Endometrial cancer (EC) is a prevalent gynecological malignancy globally, with a rising incidence trend. While classic androgens have been implicated with EC risk, the role of their 11-oxygenated metabolites is poorly understood. Here, we studied 11-oxyandrogen formation from steroid precursors in EC for the first time.

Methods

We performed in vitro studies on a panel of four EC cell lines of varying differentiation degree and molecular subtype and a control cell line of normal endometrium to assess 11-oxyandrogen formation from steroid precursors. We also characterized the transcriptomic effects of dihydrotestosterone (DHT) and 11-keto-DHT on Ishikawa and RL95-2. Key molecular players in 11-oxyandrogen metabolism and action were explored in endometrial tumors using public transcriptomic datasets.

Results

We discovered that within endometrial tumors, the formation of 11-oxyandrogens does not occur from classic androgen precursors. However, we observed distinct regulatory mechanisms at a pre-receptor level in normal endometrium compared to cancerous tissue, and between low- and high-grade tumors. Specifically, in vitro models of low-grade EC formed higher levels of bioactive 11-keto-testosterone from 11-oxyandrogen precursors compared to models of noncancerous endometrium and high-grade, TP53-mutated EC. Moreover, the potent androgen, DHT and its 11-keto homologue induced mild transcriptomic effects on androgen receptor (AR)-expressing EC model, Ishikawa. Finally, using public transcriptomic datasets, we found HSD11B2 and SRD5A2, coding for key enzymes in steroid metabolism, to be associated with better disease-specific survival, whereas higher intra-tumoral AR expression correlated with lower recurrence in TP53-wt tumors.

Conclusions

The intra-tumoral metabolism of 11-oxyandrogen precursors is characteristic for low-grade EC of non-TP53-alt molecular subtypes. Our findings support further exploration of circulating 11-oxyandrogens as prognostic biomarkers in EC.

Androgen-responsive FOXP4 is a target for endometrial carcinoma

Although low estrogen is considered to suppress uterine endometrial carcinoma, the most cases occur in the postmenopausal stage. After menopause, the production of androgen level also declines. Therefore, to resolve the above enigma, we hypothesize that the postmenopausal decline of androgen is a trigger of its progression. In the present study, to validate this hypothesis, we examine the pathological roles of androgen/AR by analyzing clinical data, culturing endometrioid cancer cell lines, and using murine models. Clinical data show that androgen receptor (AR) expression and serum dihydrotestosterone (DHT) are associated with lower disease-free survival (DFS). DHT suppresses malignant behaviors in AR-transfected human endometrial cancer cells (ECC). In ovariectomized Ptenff/PRcre/+ mice, DHT decreases the proliferation of spontaneously developed murine ECC. In AR-transfected human ECC and Ptenff/PRcre/+ mice, DHT suppresses FOXP4 expression. FOXP4-overexpressed human ECC increases, while FOXP4-knocked-down ECC shows decreased malignant behaviors. DHT/AR-mediated ECC suppression is restored by FOXP4 overexpression. The high FOXP4 expression is significantly correlated with low postoperative DFS. These findings indicate that the androgen/AR system suppresses the malignant activity of endometrial carcinoma and that downstream FOXP4 is another target molecule. These findings will also impact developments in clinical approaches to elderly health.

Cellular heterogeneity and dynamics of the human uterus in healthy premenopausal women

The human uterus is a complex and dynamic organ whose lining grows, remodels, and regenerates in every menstrual cycle or upon tissue damage. Here we applied single-cell RNA sequencing to profile more the 50,000 uterine cells from both the endometrium and myometrium of 5 healthy premenopausal individuals, and jointly analyzed the data with a previously published dataset from 15 subjects. The resulting normal uterus cell atlas contains more than 167K cells representing the lymphatic endothelium, blood endothelium, stromal, ciliated epithelium, unciliated epithelium, and immune cell populations. Focused analyses within each major cell type and comparisons with subtype labels from prior studies allowed us to document supporting evidence, resolve naming conflicts, and to propose a consensus annotation system of 39 subtypes. We release their gene expression centroids, differentially expressed genes, and mRNA patterns of literature-based markers as a shared community resource. We find many subtypes show dynamic changes over different phases of the cycle and identify multiple potential progenitor cells: compartment-wide progenitors for each major cell type, transitional cells that are upstream of other subtypes, and potential cross-lineage multipotent stromal progenitors that may be capable of replenishing the epithelial, stromal, and endothelial compartments. When compared to the healthy premenopausal samples, a postpartum and a postmenopausal uterus sample revealed substantially altered tissue composition, involving the rise or fall of stromal, endothelial, and immune cells. The cell taxonomy and molecular markers we report here are expected to inform studies of both basic biology of uterine function and its disorders.

SIGNIFICANCE

We present single-cell RNA sequencing data from seven individuals (five healthy pre-menopausal women, one post-menopausal woman, and one postpartum) and perform an integrated analysis of this data alongside 15 previously published scRNA-seq datasets. We identified 39 distinct cell subtypes across four major cell types in the uterus. By using RNA velocity analysis and centroid-centroid comparisons we identify multiple computationally predicted progenitor populations for each of the major cell compartments, as well as potential cross-compartment, multi-potent progenitors. While the function and interactions of these cell populations remain to be validated through future experiments, the markers and their "dual characteristics" that we describe will serve as a rich resource to the scientific community. Importantly, we address a significant challenge in the field: reconciling multiple uterine cell taxonomies being proposed. To achieve this, we focused on integrating historical and contemporary knowledge across multiple studies. By providing detailed evidence used for cell classification we lay the groundwork for establishing a stable, consensus cell atlas of the human uterus.

RNA modification regulator DDC in endometrial cancer affects the tumor microenvironment and patient prognosis

Uterine corpus endometrial carcinoma (UCEC) is infiltrated by immune cells, which are involved in the growth and proliferation of malignant tumors and resistance to immunotherapy. This study suggested that RNA modification regulators played an important role in the development and prognosis of UCEC. Many studies confirmed that RNA modification played an essential role in tumor immune regulation, and abnormal RNA modification contributed to tumorigenesis and cancer progression. Based on the RNA modification regulatory factors, the UCEC samples from TCGA (The Cancer Genome Atlas) were classified into two clusters, namely Cluster A and Cluster B, using unsupervised consensus clustering. We obtained DEG (differentially expressed genes) between the two clusters, and constructed a risk model of RNA modification-related genes using DEGs. Cluster A had lower RNA modification regulatory factors, richer immune cell infiltration, and better prognosis. The differentially expressed genes between the two clusters were obtained, and these genes were used for modeling. This model divided patients with UCEC into two groups. The low-risk group had better immune infiltration, and the ROC (receiver operating characteristic) curve showed that this model had good predictive efficacy. The low-risk group had a better response to immunotherapy by immune checkpoint prediction. We obtained the key gene L-dopa decarboxylase (DDC) through the intersection of LASSO model genes and GEO dataset GSE17025. We evaluated the potential biological functions of DDC. The differences in the expression of DDC were verified by immunohistochemistry. We evaluated the relationship between DDC and immune cell infiltration and verified this difference using immunofluorescence. Cluster A with low expression of RNA modification regulators has better prognosis and richer immune cell infiltration, therefore, we believed that RNA modification regulators in UCEC were closely related to the tumor microenvironment. Also, the risk score could well predict the prognosis of patients and guide immunotherapy, which might benefit patients with UCEC.

Stranger Things: New Roles and Opportunities for Androgen Receptor in Oncology Beyond Prostate Cancer

The androgen receptor (AR) is one of the oldest therapeutic targets in oncology and continues to dominate the treatment landscape for advanced prostate cancer, where nearly all treatment regimens include some form of AR modulation. In this regard, AR remains the central driver of prostate cancer cell biology. Emerging preclinical and clinical data implicate key roles for AR in additional cancer types, thereby expanding the importance of this drug target beyond prostate cancer. In this mini-review, new roles for AR in other cancer types are discussed as well as their potential for treatment with AR-targeted agents. Our understanding of these additional functions for AR in oncology expand this receptor's potential as a therapeutic target and will help guide the development of new treatment approaches.

The association of Wnt-signalling and EMT markers with clinical characteristics in women with endometrial cancer

Endometrial cancer is the most common gynecologic malignancy in the developed world. Risk stratification and treatment approaches are changing due to better understanding of tumor biology. Upregulated Wnt signaling plays an important role in cancer initiation and progression with promising potential for development of specific Wnt inhibitor therapy. One of the ways in which Wnt signaling contributes to progression of cancer, is by activating epithelial-to-mesenchymal transition (EMT) in tumor cells, causing the expression of mesenchymal markers, and enabling tumor cells to dissociate and migrate. This study analyzed the expression of Wnt signaling and EMT markers in endometrial cancer. Wnt signaling and EMT markers were significantly correlated with hormone receptors status in EC, but not with other clinico-pathological characteristics. Expression of Wnt antagonist, Dkk1 was significantly different between the ESGO-ESTRO-ESP patient risk assessment categories using integrated molecular risk assessment.

Androgens in endometrial carcinoma: the killer or helper?

PURPOSE

The aim of this review is to discuss the role of androgens in the progression of endometrial carcinoma (EC) with particular focus on the different kinds of androgenic hormones, androgen receptor (AR) and intracrine androgen metabolism.

METHODS

A comprehensive literature search within PubMed was performed. Selected publications related to androgens and EC were reviewed.

RESULTS

There are different kinds of androgenic hormones, and different kinds of androgens may have different effects. Elevated androgens (especially testosterone) have been associated with an increased EC risk in postmenopausal women. 5α-reductases (5α-Reds) and 17β-hydroxysteroid dehydrogenase type 2 (17βHSD2) pathway may inhibit the progression of EC mediated by dihydrotestosterone (DHT), but aromatases stimulate further progression of EC. The most of studies accessing the prognostic value of AR have found that AR expression may be a favorable prognostic indicator.

CONCLUSION

Androgens may have both oncogenic and tumor suppressive roles. Androgen-specific biases in metabolism and the expression of AR may contribute to the different prognosis of patients with EC.

What Role do Androgens Play in Endometrial Cancer?

The role of estrogens and progesterone in the development and progression of endometrial cancer is well-established, but there are very little data about the role of androgens. There are five different androgens produced in women: dehydroepiandrosterone sulphate (DHEAS), dehydroepiandrosterone (DHEA), androstenedione (A₄), testosterone (T) and dihydrotestosterone (DHT). The most potent hormones are T and DHT, the latter being mainly produced from T in peripheral tissues, including endometrium. Although they are considered to exert antiproliferative effects in many settings and the expression of their receptors is more often associated with a good prognosis in EC, it is still unknown in which specific settings androgens have carcinogenic or protective effects in EC.

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.

Integration of androgen hormones in endometrial cancer biology

Endometrial cancer (EC) is a gynecological pathology that affects the uterine inner lining. In recent years, genomic studies revealed continually evolving mutational landscapes of endometrial tumors that hold great potential for tailoring therapeutic strategies. This review aims to broaden our knowledge of EC biology by focusing on the role of androgen hormones. First, we discuss epidemiological evidence implicating androgens with EC pathogenesis and cover their biosynthesis and metabolism to bioactive 11-oxyandrogens. Next, we explore the endometrial tumor tissue and the altered microbiota as alternative sources of androgens and their 11-oxymetabolites in EC patients. Finally, we discuss the biological significance of androgens' genomic and nongenomic signaling as part of a medley of pathways ultimately deciding the fate of cells.

Hormonal regulation of telomerase activity and hTERT expression in steroid-regulated tissues and cancer

Naturally, in somatic cells chromosome ends (telomeres) shorten during each cell division. This process ensures to limit proliferation of somatic cells to avoid malignant proliferation; however, it leads to proliferative senescence. Telomerase contains the reverse transcriptase TERT, which together with the TERC component, is responsible for protection of genome integrity by preventing shortening of telomeres through adding repetitive sequences. In addition, telomerase has non-telomeric function and supports growth factor independent growth. Unlike somatic cells, telomerase is detectable in stem cells, germ line cells, and cancer cells to support self-renewal and expansion. Elevated telomerase activity is reported in almost all of human cancers. Increased expression of hTERT gene or its reactivation is required for limitless cellular proliferation in immortal malignant cells. In hormonally regulated tissues as well as in prostate, breast and endometrial cancers, telomerase activity and hTERT expression are under control of steroid sex hormones and growth factors. Also, a number of hormones and growth factors are known to play a role in the carcinogenesis via regulation of hTERT levels or telomerase activity. Understanding the role of hormones in interaction with telomerase may help finding therapeutical targets for anticancer strategies. In this review, we outline the roles and functions of several steroid hormones and growth factors in telomerase regulation, particularly in hormone regulated cancers such as prostate, breast and endometrial cancer.

Molecular Regulation of Androgen Receptors in Major Female Reproductive System Cancers

There are three main types of cancer in the female reproductive system, specifically ovarian cancer (OVCA), endometrial cancer (EC), and cervical cancer (CC). They are common malignant tumors in women worldwide, with high morbidity and mortality. In recent years, androgen receptors (ARs) have been found to be closely related to the occurrence, progression, prognosis, and drug resistance of these three types of tumors. This paper summarizes current views on the role of AR in female reproductive system cancer, the associations between female reproductive system cancers and AR expression and polymorphisms. AR regulates the downstream target genes transcriptional activity and the expression via interacting with coactivators/corepressors and upstream/downstream regulators and through the gene transcription mechanism of “classical A/AR signaling” or “non-classical AR signaling”, involving a large number of regulatory factors and signaling pathways. ARs take part in the processes of cancer cell proliferation, migration/invasion, cancer cell stemness, and chemotherapeutic drug resistance. These findings suggest that the AR and related regulators could target the treatment of female reproductive system cancer.

The Clinicopathological Significance and Prognostic Value of Androgen Receptor in Endometrial Carcinoma: A Meta-Analysis

Background

The role of androgen receptor (AR) in evaluating the prognosis of patients with endometrial cancer (EC) remains controversial. Here, we performed a meta-analysis to assess whether AR expression improves EC survival outcomes.

Methods

We searched related articles published before August 2021 in PubMed, EMBASE, and Web of Science. The association between AR expression and patient prognosis was estimated with hazard ratios (HRs) and odds ratios (ORs) with their corresponding 95% confidence intervals (95% CIs). The review is registered on PROSPERO, registration number: CRD42021268591.

Results

Ten studies including 1,485 patients were enrolled in the meta-analysis. The results showed that AR expression in EC tissues was associated with a better survival in crude analyses (HR = 1.63, 95% CI = 1.32–2.02, P < 0.001). However, no significant relation was found after the adjustment of the confounding factors (HR = 1.68, 95% CI = 0.75–3.75, P = 0.205). In subgroup analyses, grade 1–2 disease, stage I–II disease, negative lymph node status, and lack of the lymphovascular invasion were more common in AR-positive groups (OR = 0.47, 0.48, 0.37, and 0.57; 95% CI = 0.45–0.62, 0.35–0.65, 0.24–0.56, and 0.37–0.89). Furthermore, AR expression was more common in endometrioid cancers (OR = 2.39, 95% CI = 1.79–3.20).

Conclusions

AR expression is significantly associated favorable characteristics including low-grade disease, early-stage disease, negative lymph node status, and lack of the lymphovascular invasion and a specific histology—endometrioid cancer. However, AR is not an independent prognostic factor.

Differential Expression of Steroid Hormone Receptors and Ten Eleven Translocation Proteins in Endometrial Cancer Cells

Steroid hormones govern the complex, cyclic changes of the endometrium, predominantly through their receptors. An interplay between steroid hormones and epigenetic mechanisms controls the dynamic endometrial gene regulation. Abnormalities in expression of genes and enzymes associated with steroid hormone signaling, contribute to a disturbed hormonal equilibrium. Limited evidence suggests the involvement of TET (Ten Eleven Translocation)-mediated DNA hydroxymethylation in endometrial cancer, with some data on the use of TET1 as a potential prognostic and diagnostic biomarker, however the mechanisms guiding it and its regulation remains unexplored. This study aims to explore the changes in the expressions of TETs and steroid hormone receptors in response to estrogen and progesterone in endometrial cancer cells. Gene expression was examined using real-time PCR and protein expression was quantified using fluorescent western blotting in endometrial cancer cell lines (AN3 and RL95-2). Results indicate that TET1 and TET3 gene and protein expression was cell-specific in cancer cell-lines. Protein expression of TET1 was downregulated in AN3 cells, while TET1 and TET3 expressions were both upregulated in RL95-2 cells in response to estrogen-progesterone. Further, a decreased AR expression in AN3 cells and an increased ERα and ERβ protein expressions in RL95-2 cells was seen in response to estrogen-progesterone. PR gene and protein expression was absent from both cancer cell-lines. Overall, results imply that expressions of steroid hormones, steroid-hormone receptors and TETs are co-regulated in endometrial cancer-cells. Further studies are needed to interpret how these mechanisms fit in with DNMTs and DNA methylation in regulating endometrial biology. Understanding the role of TETs and hydroxymethylation in steroid hormone receptor regulation is crucial to comprehend how these mechanisms work together in a broader context of epigenetics in the endometrium and its pathologies.

Modifying effect of obesity on the content of sex hormones and their receptors in endometrial adenocarcinoma and its surrounding tissue

To study the effect of comorbid pathology: obesity of degree 2-3 on the level of sex steroid hormones and their receptors in the tumor and its surrounding tissue in patients with endometrial cancer (EC). Materials and methods. In 30 patients with endometrioid adenocarcinoma T1-3N0-1M0 (the main group, 15 females with obesity grade 2-3 (BMI≥35); the reference group 15 females with normal BMI) in samples of the tumor and its perifocal zone taken after surgical treatment, the levels of estradiol (E2), estrone (E1), testosterone (T), progesterone (P4), androgen receptors (AR), progesterone receptors (RP4), estrogen receptors (ERα and ERβ) were determined by ELISA method. Statistical analysis was performed with STATISTICA 10.0. Results. Obese EC patients showed longer healing of postoperative wounds, slow recovery, and more frequent tumor metastasizing to regional lymph nodes. In the tumor samples in all patients, compared with the intact endometrium, the levels of estrogens, testosterone and their receptors were higher. Obesity accompanying the malignant process led to a local increase in the levels of estrogens, testosterone, progesterone and AR, ERα and ERβ in the tumor. In the tumor samples, there were no significant differences from the presence of obesity in the levels of RP4. In the perifocal zone of the tumor in patients with comorbid pathology, compared with the parameters in the reference group, the level of E2, P4 and T was also higher, but the content of all steroid receptors was lower. Conclusion. Obesity aggravates hyperestrogenism and progesterone deficiency in adenocarcinoma and increases its enrichment with the androgen and estrogen receptors with the prevalence of ERα over ERβ that may cause the autocrine-paracrine regulation of the growth and metastasizing of the malignant process in patients with endometrial cancer.

Telomere and Telomerase-Associated Proteins in Endometrial Carcinogenesis and Cancer-Associated Survival

Risk of relapse of endometrial cancer (EC) after surgical treatment is 13% and recurrent disease carries a poor prognosis. Research into prognostic indicators is essential to improve EC management and outcome. "Immortality" of most cancer cells is dependent on telomerase, but the role of associated proteins in the endometrium is poorly understood. The Cancer Genome Atlas data highlighted telomere/telomerase associated genes (TTAGs) with prognostic relevance in the endometrium, and a recent in silico study identified a group of TTAGs and proteins as key regulators within a network of dysregulated genes in EC. We characterise relevant telomere/telomerase associated proteins (TTAPs) NOP10, NHP2, NOP56, TERF1, TERF2 and TERF2IP in the endometrium using quantitative polymerase chain reaction (qPCR) and immunohistochemistry (IHC). qPCR data demonstrated altered expression of multiple TTAPs; specifically, increased NOP10 (p = 0.03) and reduced NHP2 (p = 0.01), TERF2 (p = 0.01) and TERF2IP (p < 0.003) in EC relative to post-menopausal endometrium. Notably, we report reduced NHP2 in EC compared to post-menopausal endometrium in qPCR and IHC (p = 0.0001) data; with survival analysis indicating high immunoscore is favourable in EC (p = 0.0006). Our findings indicate a potential prognostic role for TTAPs in EC, particularly NHP2. Further evaluation of the prognostic and functional role of the examined TTAPs is warranted to develop novel treatment strategies.

Androgen Receptor Immunohistochemical Expression in Undifferentiated/Dedifferentiated Endometrial Carcinoma

Uterine undifferentiated (UC)/dedifferentiated (DEAC) carcinomas are rare malignant neoplasms. They tend to pursue an aggressive clinical course with an advanced stage at presentation. It has been found that androgen receptor (AR) might play a role as a prognostic and therapeutic marker in endometrial carcinoma. However, its expression in UC/DEAC has not been investigated. Herein, the aim of this study was to evaluate the expression of AR along with estrogen receptor (ER), progestin receptor (PR), and HER2 in UC/DEAC and also in other subtypes of high-grade endometrial carcinomas. Review of our pathology database over the period of 2011 to 2019 identified 16 UC/DEAC cases (N=16). We also randomly selected other high-grade endometrial carcinomas including FIGO 3 endometrioid carcinoma (N=9), serous carcinoma (N=8), clear cell carcinoma (N=12) and carcinosarcoma (N=10) for comparison. Immunohistochemical stains for AR, ER, PR, and HER2 were performed on all 55 cases. The protein expression was evaluated both quantitatively and qualitatively. In DEAC cases both the undifferentiated component and the well-differentiated component were recorded separately. Overall, variable degrees of AR reactivity (by Allred scoring method) was present in 63% of UC/DEACs(10/16), 67% of FIGO 3 endometrioid carcinomas (6/9), 88% of serous carcinomas (7/8), 80% of carcinosarcomas (8/10), and 9% of clear cell carcinoma (1/12). AR expression was most often seen with PR (70%) or ER (60%) staining in UC/DEACs. Thirteen cases of UC/DEACs were positive for at least 1 hormone receptor. HER2 was negative in all UC/DEACs. Almost all other high-grade carcinoma cases were negative for HER2 except 20% of carcinosarcoma (2/10) and 13% of serous carcinoma (1/8) which showed 3+ HER2. Loss of AR appears to be associated with worse clinicopathologic parameters in UC/DEAC. AR is highly expressed in UC/DEAC, and in the majority of FIGO 3 endometrioid carcinomas, serous carcinomas, and carcinosarcoma. These findings suggest a potential role for androgen inhibitors in the management of patients with these tumors.

The effect of pre-analytical variables on downstream application and data analysis of human endometrial biopsies

STUDY QUESTION

What are the effects of pre-analytical variables on the downstream analysis of patient-derived endometrial biopsies?

SUMMARY ANSWER

There are distinct differences in the protein levels of the master regulator of oxygen homeostasis, hypoxia-inducible factor-1-alpha (HIF1α), and the protein and mRNA levels of three related genes, carbonic anhydrase 9 (CA9), vascular endothelial growth factor A (VEGFA) and progesterone receptor (PR) in human endometrial biopsies, depending on the pre-analytical variables: disease status (cancer vs benign), timing of biopsy (pre- vs post-hysterectomy) and type of biopsy (pipelle vs full-thickness).

WHAT IS KNOWN ALREADY

Patient-derived biopsies are vital to endometrial research, but pre-analytical variables relating to their collection may affect downstream analysis, as is evident in other tissues.

STUDY DESIGN SIZE DURATION

A prospective observational study including patients undergoing hysterectomy for endometrial cancer (EC) or benign indications was conducted at a large tertiary gynaecological unit in the UK. Endometrial biopsies were obtained at different time points (pre- or post-hysterectomy) using either a pipelle endometrial sampler or as a full-thickness wedge biopsy.

PARTICIPANTS/MATERIALS SETTING METHODS

The changes in HIF1α, CA9, VEGFA and PR protein levels were measured by semi-quantitative analysis of immunostaining, and the expression levels of three genes (CA9, VEGFA and PR) were investigated by quantitative real-time PCR, in endometrial biopsies from 43 patients undergoing hysterectomy for EC (n = 22) or benign gynaecological indications (n = 21).

MAIN RESULTS AND THE ROLE OF CHANCE

An increase in HIF1α immunostaining was observed in EC versus benign endometrium (functionalis glands) obtained pre-hysterectomy (P < 0.001). An increase in CA9 immunostaining was observed in EC versus benign endometrial functionalis glands at both pre- and post-hysterectomy time points (P = 0.03 and P = 0.003, respectively). Compared with benign endometrial pipelle samples, EC samples demonstrated increased mRNA expression of CA9 (pre-hysterectomy P < 0.001, post-hysterectomy P = 0.008) and VEGFA (pre-hysterectomy P = 0.004, post-hysterectomy P = 0.002). In benign uteri, HIF1α immunoscores (functionalis glands, P = 0.03 and stroma, P = 0.009), VEGFA immunoscores (functionalis glands, P = 0.03 and stroma, P = 0.01) and VEGFA mRNA levels (P = 0.008) were increased in matched post-hysterectomy versus pre-hysterectomy samples. Similarly, in EC, an increase in VEGFA immunoscores (epithelial and stromal) and VEGFA mRNA expression was observed in the matched post-hysterectomy versus pre-hysterectomy biopsies (P = 0.008, P = 0.004 and P = 0.018, respectively). Full-thickness benign post-hysterectomy endometrial biopsies displayed increased VEGFA (P = 0.011) and PR (P = 0.006) mRNA expression compared with time-matched pipelle biopsies.

LARGE SCALE DATA

N/A.

LIMITATIONS REASONS FOR CAUTION

This descriptive study explores the effect of pre-analytical variables on the expression of four proteins and three hypoxia-related genes in a limited number of endometrial biopsies from patients with EC and benign controls. Due to the small number, it was not possible to investigate other potential variables such as menstrual cycle phase, region-specific differences within the endometrium, grade and stage of cancer, and surgical technicalities.

WIDER IMPLICATIONS OF THE FINDINGS

Careful consideration of the effects of these pre-analytical variables is essential when interpreting data relating to human endometrial biopsies. A standardized approach to endometrial tissue collection is essential to ensure accurate and clinically transferrable data.

STUDY FUNDING/COMPETING INTERESTS

The authors have no conflicts of interest to declare. The work included in this manuscript was funded by Wellbeing of Women project grants RG1073 and RG2137 (D.K.H.), Wellbeing of Women Entry-Level Scholarship ELS706 and Medical Research Council MR/V007238/1 (A.M./D.K.H.), Liverpool Women's Hospital Cancer Charity (M.A.) and University of Liverpool (L.B., L.R. and E.N.).

Mixed Epithelial and Stromal Tumor Family of Kidney (Adult Cystic Nephroma, Mixed Epithelial and Stromal Tumor): Retrospective Clinicopathological Evaluation

OBJECTIVE

Tumors belonging to the mixed epithelial stromal tumor family (MESTF) are rare; thus clinicopathological experience about them are limited. Each epithelial and stromal component shows different patterns in these tumors.

MATERIAL AND METHOD

Clinicopathological features of 11 MESTF cases that were diagnosed between 2000 and 2021 at a single center were evaluated.

RESULTS

Ten of the 11 patients were female (F:M = 10:1). The mean age of the females was 47 (31-63) years; the male patient was 45 years old. The mean tumor diameter was 6.7 (3.5-19) cm. All tumors had varying proportions of cystic and solid components. Eight cases were well circumscribed, and the others had distinct but irregular borders. Two of the tumors with irregular borders were bulging into the renal sinus. The epithelial component was dominant in most cases. In the epithelial component, macrocyst, microcyst, and tubules were the most common patterns and the most common types of lining epithelium were flat, cuboidal and hobnail. The stromal component was variable in most cases and included hypocellular (mostly collagenous) and cellular areas. In most cases, the cellular stroma had an ovarian-like appearance. Among the other features observed, hyalinization and dystrophic calcification were common. The positivity for estrogen and progesterone receptor in the stromal component was observed in almost all female cases.

CONCLUSION

MESTF, which has distinctive features, should be considered in the differential diagnosis of cystic kidney tumors.

Novel microarchitecture of human endometrial glands: implications in endometrial regeneration and pathologies

BACKGROUND

Human endometrium remains a poorly understood tissue of the female reproductive tract. The superficial endometrial functionalis, the site of embryo implantation, is repeatedly shed with menstruation, and the stem cell-rich deeper basalis is postulated to be responsible for the regeneration of the functionalis. Two recent manuscripts have demonstrated the 3D architecture of endometrial glands. These manuscripts have challenged and replaced the prevailing concept that these glands end in blind pouches in the basalis layer that contain stem cells in crypts, as in the intestinal mucosa, providing a new paradigm for endometrial glandular anatomy. This necessitates re-evaluation of the available evidence on human endometrial regeneration in both health and disease in the context of this previously unknown endometrial glandular arrangement.

OBJECTIVE AND RATIONALE

The aim of this review is to determine if the recently discovered glandular arrangement provides plausible explanations for previously unanswered questions related to human endometrial biology. Specifically, it will focus on re-appraising the theories related to endometrial regeneration, location of stem/progenitor cells and endometrial pathologies in the context of this recently unravelled endometrial glandular organization.

SEARCH METHODS

An extensive literature search was conducted from inception to April 2021 using multiple databases, including PubMed/Web of Science/EMBASE/Scopus, to select studies using keywords applied to endometrial glandular anatomy and regeneration, and the references included in selected publications were also screened. All relevant publications were included.

OUTCOMES

The human endometrial glands have a unique and complex architecture; branched basalis glands proceed in a horizontal course adjacent to the myometrium, as opposed to the non-branching, vertically coiled functionalis glands, which run parallel to each other as is observed in intestinal crypts. This complex network of mycelium-like, interconnected basalis glands is demonstrated to contain endometrial epithelial stem cells giving rise to single, non-branching functionalis glands. Several previous studies that have tried to confirm the existence of epithelial stem cells have used methodologies that prevent sampling of the stem cell-rich basalis. More recent findings have provided insight into the efficient regeneration of the human endometrium, which is preferentially evolved in humans and menstruating upper-order primates.

WIDER IMPLICATIONS

The unique physiological organization of the human endometrial glandular element, its relevance to stem cell activity and scarless endometrial regeneration will inform reproductive biologists and clinicians to direct their future research to determine disease-specific alterations in glandular anatomy in a variety of endometrial pathological conditions.

The role of androgens in women's health and wellbeing

Androgens in women, as well as in men, are intrinsic to maintenance of (i) reproductive competency, (ii) cardiac health, (iii) appropriate bone remodeling and mass retention, (iii) muscle tone and mass, and (iv) brain function, in part, through their mitigation of neurodegenerative disease effects. In recognition of the pluripotency of endogenous androgens, exogenous androgens, and selected congeners, have been prescribed off-label for several decades to treat low libido and sexual dysfunction in menopausal women, as well as, to improve physical performance. However, long-term safety and efficacy of androgen administration has yet to be fully elucidated. Side effects often observed include (i) hirsutism, (ii) acne, (iii) deepening of the voice, and (iv) weight gain but are associated most frequently with supra-physiological doses. By contrast, short-term clinical trials suggest that the use of low-dose testosterone therapy in women appears to be effective, safe and economical. There are, however, few clinical studies, which have focused on effects of androgen therapy on pre- and post-menopausal women; moreover, androgen mechanisms of action have not yet been thoroughly explained in these subjects. This review considers clinical effects of androgens on women's health in order to prevent chronic diseases and reduce cancer risk in gynecological tissues.

Fallopian tube epithelial cells express androgen receptor and have a distinct hormonal responsiveness when compared with endometrial epithelium

STUDY QUESTION

How does steroid receptor expression, proliferative activity and hormone responsiveness of the fallopian tube (FT) epithelium compare to that of the endometrial epithelium?

SUMMARY ANSWER

Proliferative indices, hormone receptor expression-scores and in vitro response to oestrogen and androgens of the human FT demonstrate a distinct pattern from the matched endometrium.

WHAT IS KNOWN ALREADY

The FT epithelium exists as a continuum of the endometrium, and both express steroid hormone receptors. The ovarian steroid hormones regulate cyclical proliferation and regeneration of the endometrium, but their effects on steroid hormone receptor expression and proliferation in the FT have not yet been fully elucidated.

STUDY DESIGN, SIZE, DURATION

We included women with proven fertility, undergoing hysterectomy and bilateral salpingo-oophorectomy for benign, gynaecological conditions at Liverpool Women's NHS Foundation Trust. They had no known endometrial or tubal pathology and were not on hormonal treatments for at least 3 months preceding sample collection in this prospective observational study (conducted between 2010 and 2018). A full-thickness sample of the endometrium and a sample from the FT were collected from each woman.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The differential protein and mRNA levels of steroid hormone receptors, oestrogen receptors α and β, androgen receptor (AR) and progesterone receptor (PR), and the proliferative marker (Ki67) of the endometrium and the FT tissue samples from 47 healthy women undergoing surgery (37 premenopausal and 10 postmenopausal) were investigated using immunohistochemistry and quantitative real-time PCR. The comparative responsiveness to oestrogen and androgen of the endometrium and the fimbrial end of the FT was analysed using an in vitro short-term explant culture model. The endpoints assessed in the explants were the changes in mRNA and protein levels for AR, PR and the epithelial proliferative index after 24 h treatment with oestradiol (E2) or dihydrotestosterone (DHT).

MAIN RESULTS AND THE ROLE OF CHANCE

The premenopausal endometrial functionalis glands (FG) displayed the well-known cyclic variation in cellular proliferation and steroid receptor scores. Compared with the endometrial FG, the matched FT epithelium (both fimbrial or isthmic ends) displayed a significantly lower proportion of cells expressing Ki67 (2.8% ± 2.2%, n = 18 vs 30.0% ± 26.3%, n = 16, P = 0.0018, respectively) accompanied with a significantly higher AR immunoscores (6.7 ± 2.7, n = 16 vs 0.3 ± 1.0, n = 10, P = 0.0136). The proportion of cells expressing Ki67 and the AR immunoscores of the FT epithelium correlated positively with endometrial luminal epithelium (r = 0.62, P = 0.005, and r = 0.68, P = 0.003, respectively). In vitro experiments suggested the tubal explants to be apparently less responsive to E2 yet more sensitive to DHT compared with the matched endometrium explants.

LIMITATIONS, REASONS FOR CAUTION

The short-term in vitro nature of the tissue explant cultures used in the study may not be representative of how different anatomical regions of the endometrium and FT behave in vivo. Our study included a high proportion of older premenopausal women with a regular menstrual cycle, which may therefore affect extrapolation of findings to a younger group.

WIDER IMPLICATIONS OF THE FINDINGS

Advancing our understanding of tubal and endometrial epithelial cell function has important implications for the diagnosis and treatment of diseases such as infertility, ectopic pregnancy, endometriosis and cancer.

STUDY FUNDING/COMPETING INTEREST(S)

The work included in this article was funded by Wellbeing of Women project grants RG1073 and RG2137 (D.K.H.) and Wellbeing of Women Entry-Level Scholarship ELS706 (A.M). A.M. was also supported by an NIHR ACF fellowship grant. Further support received from Liverpool Women's Hospital NHS Trust (S.M.), University of Liverpool (E.B. and A.W.). All authors declare there are no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Anterior Gradient Protein 3 and S100 Calcium-Binding Protein P Levels in Different Endometrial Epithelial Compartments May Play an Important Role in Recurrent Pregnancy Failure

Recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL) are distressing conditions without effective treatments. The luminal epithelium (LE) is integral in determining receptivity of the endometrium, whereas functionalis glands and stroma aid in nurturing early embryo development. Calcium signalling pathways are known to be of vital importance to embryo implantation and pregnancy establishment, and anterior gradient protein 3 (AGR3) and S100 calcium-binding protein P (S100P) are involved with these pathways. We initially examined 20 full-thickness endometrial biopsies from premenopausal women across the menstrual cycle to characterize levels of AGR3 protein in each endometrial sub-region at the cellular level. A further 53 endometrial pipelle biopsies collected in the window of implantation were subsequently assessed to determine differential endometrial AGR3 and S100P levels relevant to RIF (n = 13) and RPL (n = 10) in comparison with parous women (n = 30) using immunohistochemistry. Significantly higher AGR3 and S100P immunostaining was observed in ciliated cells of the LE of women with recurrent reproductive failure compared with parous women, suggesting aberrant subcellular location-associated pathophysiology for these conditions. The nuclear localisation of S100P may allow transcriptional regulatory function, which is necessary for implantation of a viable pregnancy. Further work is thus warranted to assess their utility as diagnostic/therapeutic targets.

Aberrant Dyskerin Expression Is Related to Proliferation and Poor Survival in Endometrial Cancer

Simple Summary

Telomeres are the protective caps at the ends of chromosomes, and they are maintained by an enzyme called telomerase. Telomerase activity allows rapid reproduction of the cells (proliferation) of the lining of the womb (endometrium). Telomerase levels are high in cancers in general, including in endometrial cancer. Dyskerin is one of the main components of the telomerase enzyme. While the other main components of telomerase have been studied in endometrial cancer, there are no previous studies on dyskerin in the endometrium. Our study shows that dyskerin levels are significantly lower in endometrial cancer and levels are linked to the survival of women. Experimentally increasing dyskerin protein in endometrial cells in the laboratory reduces the rate of cell proliferation. Consequently, we propose that dyskerin may be a regulator of endometrial cancer cell proliferation, and further studies are required to test if it can be targeted to develop new therapies for endometrial cancer.

Abstract

Dyskerin is a core-component of the telomerase holo-enzyme, which elongates telomeres. Telomerase is involved in endometrial epithelial cell proliferation. Most endometrial cancers (ECs) have high telomerase activity; however, dyskerin expression in human healthy endometrium or in endometrial pathologies has not been investigated yet. We aimed to examine the expression, prognostic relevance, and functional role of dyskerin in human EC. Endometrial samples from a cohort of 175 women were examined with immunohistochemistry, immunoblotting, and qPCR. The EC cells were transfected with Myc-DDK-DKC1 plasmid and the effect of dyskerin overexpression on EC cell proliferation was assessed by flow cytometry. Human endometrium expresses dyskerin (DKC1) and dyskerin protein levels are significantly reduced in ECs when compared with healthy postmenopausal endometrium. Low dyskerin immunoscores were potentially associated with worse outcomes, suggesting a possible prognostic relevance. Cancer Genome Atlas (TCGA) ECs dataset (n = 589) was also interrogated. The TCGA dataset further confirmed changes in DKC1 expression in EC with prognostic significance. Transient dyskerin overexpression had a negative effect on EC cell proliferation. Our data demonstrates a role for dyskerin in normal endometrium for the first time and confirms aberrant expression with possible prognostic relevance in EC. Interventions aimed at modulating dyskerin levels may provide novel therapeutic options in EC.

AKR1C3 Is Associated with Better Survival of Patients with Endometrial Carcinomas

The aldo-keto reductase (AKR) superfamily is gaining attention in cancer research. AKRs are involved in important biochemical processes and have crucial roles in carcinogenesis and chemoresistance. The enzyme AKR1C3 has many functions, which include production of prostaglandins, androgens and estrogens, and metabolism of different chemotherapeutics; AKR1C3 is thus implicated in the pathophysiology of different cancers. Endometrial and ovarian cancers represent the majority of gynecological malignancies in developed countries. Personalized treatments for these cancers depend on identification of prognostic and predictive biomarkers that allow stratification of patients. In this study, we evaluated the immunohistochemical (IHC) staining of AKR1C3 in 123 paraffin-embedded samples of endometrial cancer and 99 samples of ovarian cancer, and examined possible correlations between expression of AKR1C3 and other clinicopathological data. The IHC expression of AKR1C3 was higher in endometrial cancer compared to ovarian cancer. In endometrioid endometrial carcinoma, high AKR1C3 IHC expression correlated with better overall survival (hazard ratio, 0.19; 95% confidence interval, 0.06−0.65, p = 0.008) and with disease-free survival (hazard ratio, 0.328; 95% confidence interval, 0.12–0.88, p = 0.027). In patients with ovarian cancer, there was no correlation between AKR1C3 IHC expression and overall and disease-free survival or response to chemotherapy. These results demonstrate that AKR1C3 is a potential prognostic biomarker for endometrioid endometrial cancer.

Endometriosis Is Associated with a Significant Increase in hTERC and Altered Telomere/Telomerase Associated Genes in the Eutopic Endometrium, an Ex-Vivo and In Silico Study

Telomeres protect chromosomal ends and they are maintained by the specialised enzyme, telomerase. Endometriosis is a common gynaecological disease and high telomerase activity and higher hTERT levels associated with longer endometrial telomere lengths are characteristics of eutopic secretory endometrial aberrations of women with endometriosis. Our ex-vivo study examined the levels of hTERC and DKC1 RNA and dyskerin protein levels in the endometrium from healthy women and those with endometriosis (n = 117). The in silico study examined endometriosis-specific telomere- and telomerase-associated gene (TTAG) transcriptional aberrations of secretory phase eutopic endometrium utilising publicly available microarray datasets. Eutopic secretory endometrial hTERC levels were significantly increased in women with endometriosis compared to healthy endometrium, yet dyskerin mRNA and protein levels were unperturbed. Our in silico study identified 10 TTAGs (CDKN2A, PML, ZNHIT2, UBE3A, MCCC2, HSPC159, FGFR2, PIK3C2A, RALGAPA1, and HNRNPA2B1) to be altered in mid-secretory endometrium of women with endometriosis. High levels of hTERC and the identified other TTAGs might be part of the established alteration in the eutopic endometrial telomerase biology in women with endometriosis in the secretory phase of the endometrium and our data informs future research to unravel the fundamental involvement of telomerase in the pathogenesis of endometriosis.

Human Endometrial Carcinogenesis Is Associated with Significant Reduction in Long Non-Coding RNA, TERRA

Telomeres are transcribed as long non-coding RNAs called TERRAs (Telomeric repeat containing RNA) that participate in a variety of cellular regulatory functions. High telomerase activity (TA) is associated with endometrial cancer (EC). This study aimed to examine the levels of three TERRAs, transcribed at chromosomes 1q-2q-4q-10q-13q-22q, 16p and 20q in healthy (n = 23) and pathological (n = 24) human endometrium and to examine their association with cellular proliferation, TA and telomere lengths. EC samples demonstrated significantly reduced levels of TERRAs for Chromosome 16p (Ch-16p) (p < 0.002) and Chromosome 20q (Ch-20q) (p = 0.0006), when compared with the postmenopausal samples. No significant correlation was found between TERRA levels and TA but both Ch-16p and Ch-20q TERRA levels negatively correlated with the proliferative marker Ki67 (r = -0.35, p = 0.03 and r = -0.42, p = 0.01 respectively). Evaluation of single telomere length analysis (STELA) at XpYp telomeres demonstrated a significant shortening in EC samples when compared with healthy tissues (p = 0.002). We detected TERRAs in healthy human endometrium and observed altered individual TERRA-specific levels in malignant endometrium. The negative correlation of TERRAs with cellular proliferation along with their significant reduction in EC may suggest a role for TERRAs in carcinogenesis and thus future research should explore TERRAs as potential therapeutic targets in EC.

Evaluating the efficacy of enzalutamide and the development of resistance in a preclinical mouse model of type-I endometrial carcinoma

Androgen Receptor (AR) signaling is a critical driver of hormone-dependent prostate cancer and has also been proposed to have biological activity in female hormone-dependent cancers, including type I endometrial carcinoma (EMC). In this study, we evaluated the preclinical efficacy of a third-generation AR antagonist, enzalutamide, in a genetic mouse model of EMC, Sprr2f-Cre;Pten^fl/fl. In this model, ablation of Pten in the uterine epithelium leads to localized and distant malignant disease as observed in human EMC. We hypothesized that administering enzalutamide through the diet would temporarily decrease the incidence of invasive and metastatic carcinoma, while prolonged administration would result in development of resistance and loss of efficacy. Short-term treatment with enzalutamide reduced overall tumor burden through increased apoptosis but failed to prevent progression of invasive and metastatic disease. These results suggest that AR signaling may have biphasic, oncogenic and tumor suppressive roles in EMC that are dependent on disease stage. Enzalutamide treatment increased Progesterone Receptor (PR) expression within both stromal and tumor cell compartments. Prolonged administration of enzalutamide decreased apoptosis, increased tumor burden and resulted in the clonal expansion of tumor cells expressing high levels of p53 protein, suggestive of acquired Trp53 mutations. In conclusion, we show that enzalutamide induces apoptosis in EMC but has limited efficacy overall as a single agent. Induction of PR, a negative regulator of endometrial proliferation, suggests that adding progestin therapy to enzalutamide administration may further decrease tumor burden and result in a prolonged response.

Histological 3D reconstruction and in vivo lineage tracing of the human endometrium

Regular menstrual shedding and repair of the endometrial functionalis is unique to humans and higher-order primates. The current consensus postulates endometrial glands to have a single-tubular architecture, where multi-potential stem cells reside in the blind-ending glandular-bases. Utilising fixed samples from patients, we have studied the three-dimensional (3D) micro-architecture of the human endometrium. We demonstrate that some non-branching, single, vertical functionalis glands originate from a complex horizontally interconnecting network of basalis glands. The existence of a multipotent endometrial epithelial stem cell capable of regenerating the entire complement of glandular lineages was demonstrated by in vivo lineage tracing, using naturally occurring somatic mitochondrial DNA mutations as clonal markers. Vertical tracking of mutated clones showed that at least one stem-cell population resides in the basalis glands. These novel findings provide insight into the efficient and scar-less regenerative potential of the human endometrium. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

High serum Androgen and Insulin concentrations increase the tendency of Endometrial Carcinoma

Purpose: The objective of the study was to evaluate the important role played by androgen and insulin in the development of endometrial carcinoma (EC), and their combined effect on EC risk.

Methods: We enrolled 510 type I EC patients and 510 age-, time-, and nationality-matched subjects into this study. Metabolic and hormonal parameters of enrolled subjects were examined. Univariate and multivariate logistic regression analyses for EC and control subjects were performed. Type I EC risk was evaluated with respect to testosterone, androstenedione, and insulin levels based on odds ratios (ORs) using stratified data.

Results: EC risk was positively associated with C-peptide, estrone, androgen (including testosterone and androstenedione) and insulin levels, BMI, WHR, family history of cancer, nulliparity, irregular menstruation, diabetes, and hypertension. In multivariate logistic regression models, high C-peptide and testosterone levels, diabetes, and hypertension were independent risk factors after adjustment for BMI, WHR, family history of cancer, high serum insulin, and estrone levels. Increased serum total testosterone and insulin levels were positively correlated with EC risk in total, premenopausal, and postmenopausal women. Androstenedione was correlated with EC in total and postmenopausal, but not in premenopausal subjects. Compared with higher testosterone and insulin, odds ratios (ORs) for higher testosterone with lower insulin and lower testosterone with higher insulin were decreased in total, premenopausal, and postmenopausal women. Similarly, compared to both higher FAI and insulin, ORs for higher FAI with lower insulin and lower FAI with higher insulin were decreased in all three groups. Coordinately, ORs for higher androstenedione with lower insulin and lower androstenedione with higher insulin were decreased in total and postmenopausal, but not premenopausal subjects.

Conclusions: These findings suggested that androgen and insulin were risk factors of type I EC, and relatively high levels of both testosterone and insulin synergistically affected EC risk.

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.

An immune competent orthotopic model of endometrial cancer with metastasis

Endometrial cancer is the most common gynecologic malignancy in the U.S. with metastatic disease remaining the major cause of patient death. Therapeutic strategies have remained essentially unchanged for decades. A significant barrier to progression in treatment modalities stems from a lack of clinically applicable in vivo models to accurately mimic endometrial cancer; specifically, ones that form distant metastases and maintain an intact immune system. To address this problem, we have established the first immune competent murine orthotopic tumor model for metastatic endometrial cancer by creating a green fluorescent protein labeled cell line from an endometrial cancer that developed in a Pgr ^cre/+ Pten ^f/f Kras ^G12D genetically engineered mouse. These cancer cells were grafted into the abraded uterine lumen of ovariectomized recipient mice treated with estrogen and subsequently developed local and metastatic endometrial tumors. We noted primary tumor formation in 59% mixed background and 86% of C57BL/6 animals at 4 weeks and distant lung metastases in 78% of mice after 2 months. This immunocompetent orthotopic tumor model closely resembles some human metastatic endometrial cancer, modeling both local metastasis and hematogenous spread to lung and has significant potential to advance the study of endometrial cancer and its metastasis.

Validation of Androgen Receptor loss as a risk factor for the development of brain metastases from ovarian cancers

Background

Central nervous system (CNS) spreading from epithelial ovarian carcinoma (EOC) is an uncommon but increasing phenomenon. We previously reported in a small series of 11 patients a correlation between Androgen Receptor (AR) loss and localization to CNS. Aims of this study were: to confirm a predictive role of AR loss in an independent validation cohort; to evaluate if AR status impacts on EOC survival.

Results

We collected an additional 29 cases and 19 controls as validation cohort. In this independent cohort at univariate analysis, cases exhibited lower expression of AR, considered both as continuous (p <  0.001) and as discrete variable (10% cut-off: p <  0.003; Immunoreactive score: p <  0.001). AR negative EOC showed an odds ratio (OR) = 8.33 for CNS dissemination compared with AR positive EOC. Kaplan-Meier curves of the combined dataset, combining data of new validation cohort with the previously published cohort, showed that AR <  10% significantly correlates with worse outcomes (p = 0.005 for Progression Free Survival (PFS) and p = 0.002 for brain PFS (bPFS) respectively).

Comparison of AR expression between primary tissue and paired brain metastases in the combined dataset did not show any statistically significant difference.

Conclusions

We confirmed AR loss as predictive role for CNS involvement from EOC in an independent cohort of cases and controls. Early assessment of AR status could improve clinical management and patients’ prognosis.

Human Uterine Biopsy: Research Value and Common Pitfalls

The human uterus consists of the inner endometrium, the myometrium, and the outer serosa. Knowledge of the function of the uterus in health and disease is relevant to reproduction, fertility, embryology, gynaecology, endocrinology, and oncology. Research performed on uterine biopsies is essential to further the current understanding of human uterine biology. This brief review explores the value of the uterine biopsy in gynaecological and human fertility research and explores the common problems encountered when analysing data generated from different types of uterine biopsies, with the aim of improving the quality, reproducibility, and clinical translatability of future research.

Therapeutic Targets and Opportunities in Endometrial Cancer: Update on Endocrine Therapy and Nonimmunotherapy Targeted Options

Worldwide, the incidence of endometrial cancer is increasing. Although the prognosis remains good for patients diagnosed with early-stage disease, for those diagnosed with recurrent or metastatic disease, options have been limited, and prognosis is short. Optimizing and identifying new well-tolerated treatments for women living with endometrial cancer is a top priority. A new era is dawning where we are starting to see the integration of clinically relevant genomic and pathologic data to inform and refine treatment strategies for women with endometrial cancer. Here, we focus on reviewing nonimmunotherapy-based targeted treatment options and emerging directions for women with endometrial cancer.

The androgen receptor expression and association with patient's survival in different cancers

To understand the androgen receptor (AR) in different human malignancies, we conducted a pan-cancer analysis of AR in different tumor tissues and association with patient survival and obtained AR expression data from The Cancer Genome Atlas. Pan-Cancer Analysis of AR indicated that 12 tumor types had decreased AR expression in the tumor, while glioblastoma multiforme has overexpressed AR. The survival analysis showed that high AR mRNA is associated with poor survival of stomach adenocarcinoma and low-grade glioma, but better survival of adrenocortical carcinoma, kidney renal clear cell carcinoma, acute myeloid leukemia, liver hepatocellular carcinoma, ovarian serous cystadenocarcinoma, and skin cutaneous melanoma based on AR mRNA, protein or AR-score. AR was associated with different clinical characteristics and AR correlated genes enriched in cancer-related pathways. These data indicate that AR signaling may be strongly associated with some cancer development and patients' survival, which is promising for potential treatment using antiandrogen therapies.

Enriching Personalized Endometrial Cancer Research with the Harmonization of Biobanking Standards

Endometrial cancer is the commonest gynecological cancer, with an incidence predicted to escalate by a further 50-100% before 2025, due to the rapid rise in risk factors such as obesity and increased life expectancy. Endometrial cancer associated mortality is also rising, depicting the need for translatable research to improve our understanding of the disease. Rapid translation of scientific discoveries will facilitate the development of new diagnostic, prognostic and therapeutic strategies. Biobanks play a vital role in providing biospecimens with accompanying clinical data for personalized translational research. Wide variation in collection, and pre-analytic variations in processing and storage of bio-specimens result in divergent and irreproducible data from multiple studies that are unsuitable for collation to formulate robust conclusions. Harmonization of biobanking standards is thus vital, in facilitating international multi-center collaborative studies with valuable outcomes to improve personalized treatments. This review will detail the pitfalls in the biobanking of biosamples from women with cancer in general, and describe the recent international harmonization project that developed standardized research tools to overcome these challenges and to enhance endometrial cancer research, which will facilitate future development of personalized novel diagnostic strategies and treatments.

Abnormally located SSEA1+/SOX9+ endometrial epithelial cells with a basalis-like phenotype in the eutopic functionalis layer may play a role in the pathogenesis of endometriosis

STUDY QUESTION

Is endometriosis associated with abnormally located endometrial basalis-like (SSEA1+/SOX9+) cells in the secretory phase functionalis and could they contribute to ectopic endometriotic lesion formation?

SUMMARY ANSWER

Women with endometriosis had an abnormally higher number of basalis-like SSEA1+/SOX9+ epithelial cells present in the stratum functionalis and, since these cells formed 3D structures in vitro with phenotypic similarities to ectopic endometriotic lesions, they may generate ectopic lesions following retrograde menstruation.

WHAT IS KNOWN ALREADY

Endometrial basalis cells with progenitor potential are postulated to play a role in the pathogenesis of endometriosis and SSEA1 and nuclear SOX9 (nSOX9) mark basalis epithelial cells that also have some adenogenic properties in vitro. Induction of ectopic endometriotic lesions in a baboon model of endometriosis produces characteristic changes in the eutopic endometrium. Retrograde menstruation of endometrial basalis cells is proposed to play a role in the pathogenesis of endometriosis.

STUDY DESIGN, SIZE, DURATION

This prospective study included endometrial samples from 102 women with and without endometriosis undergoing gynaecological surgery and from six baboons before and after induction of endometriosis, with in vitro assays examining the differentiation potential of human basalis-like cells.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study was conducted at a University Research Institute. SSEA1 and SOX9 expression levels were examined in human endometrial samples from women aged 18-55 years (by immunohistochemistry (IHC) and qPCR) and from baboons (IHC). The differential gene expression and differentiation potential was assessed in freshly isolated SSEA1+ endometrial epithelial cells from women with and without endometriosis (n = 8/group) in vitro. In silico analysis of selected published microarray datasets identified differential regulation of genes of interest for the mid-secretory phase endometrium of women with endometriosis relative to that of healthy women without endometriosis.

MAIN RESULTS AND THE ROLE OF CHANCE

Women with endometriosis demonstrated higher number of basalis-like cells (SSEA1+, nSOX9+) in the functionalis layer of the eutopic endometrium compared with the healthy women without endometriosis in the secretory phase of the cycle (P < 0.05). Induction of endometriosis resulted in a similar increase in basalis-like epithelial cells in the eutopic baboon endometrium. The isolated SSEA1+ epithelial cells from the eutopic endometrium of women with endometriosis had higher expression of OCT4, NANOG, FUT4 mRNA (P = 0.05, P = 0.007, P = 0.018, respectively) and they differentiated into ectopic endometriotic gland-like structures in 3D culture, but not into mesodermal lineages (adipose or bone cells).

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Small sample size. Bioinformatics analysis and results depends on the quality of published microarray datasets and the stringency of patient selection criteria employed. Differentiation of SSEA-1+ cells was only examined for two mesodermal lineages (adipogenic and osteogenic).

WIDER IMPLICATIONS OF THE FINDINGS

Since endometrial epithelial cells with SSEA1+/nSOX9+ basalis-like phenotype generate endometriotic gland-like structures in vitro, they may potentially be a therapeutic target for endometriosis. An in depth analysis of the function of basalis-like eutopic endometrial epithelial cells might provide insights into their potential deregulation in other disorders of the endometrium including heavy menstrual bleeding and endometrial cancer where their function may be aberrant.

STUDY FUNDING/COMPETING INTEREST(S)

We acknowledge the support by Wellbeing of Women project grant RG1073 (D.K.H., C.E.G.) and R01 HD083273 from the National Institutes of Health (A.T.F.). We also acknowledge the support of Liverpool Women's Hospital Foundation Trust (J.D.), Institute of Translational Medicine (L.D.S., H.A.L., A.J.V., D.K.H.), University of Liverpool, the National Health and Medical Research Council of Australia ID 1042298 (C.E.G.) and the Victorian Government Operational Infrastructure Support Fund. All authors declare no conflict of interest.

Telomerase and Telomeres in Endometrial Cancer

Telomeres at the termini of human chromosomes are shortened with each round of cell division due to the “end replication problem” as well as oxidative stress. During carcinogenesis, cells acquire or retain mechanisms to maintain telomeres to avoid initiation of cellular senescence or apoptosis and halting cell division by critically short telomeres. The unique reverse transcriptase enzyme complex, telomerase, catalyzes the maintenance of telomeres but most human somatic cells do not have sufficient telomerase activity to prevent telomere shortening. Tissues with high and prolonged replicative potential demonstrate adequate cellular telomerase activity to prevent telomere erosion, and high telomerase activity appears to be a critical feature of most (80–90%) epithelial cancers, including endometrial cancer. Endometrial cancers regress in response to progesterone which is frequently used to treat advanced endometrial cancer. Endometrial telomerase is inhibited by progestogens and deciphering telomere and telomerase biology in endometrial cancer is therefore important, as targeting telomerase (a downstream target of progestogens) in endometrial cancer may provide novel and more effective therapeutic avenues. This review aims to examine the available evidence for the role and importance of telomere and telomerase biology in endometrial cancer.

Postmenopausal Androgen Metabolism and Endometrial Cancer Risk in the Women's Health Initiative Observational Study

Background

After menopause, several androgens continue to be produced primarily by the adrenal glands; these can be converted into estrogens via aromatization or into androgen metabolites. It is unclear if androgens are associated with endometrial cancer risk independently of their being precursors to estrogens or if alternative metabolic pathways influence risk.

Methods

We measured prediagnostic serum concentrations of 12 androgens and their metabolites using highly sensitive liquid chromatography-tandem mass spectrometry assays in a nested case-control study of postmenopausal women from the Women's Health Initiative Observational Study (313 endometrial cancer case subjects, 354 matched control subjects). Estrogens were previously assayed. We used conditional logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for endometrial cancer with adjustment for confounders.

Results

Compared to the lowest concentrations, the highest levels of adrenal androgens were associated with increased endometrial cancer risk: dehydroepiandrosterone (5th vs 1st quintile: OR = 1.85, 95% CI = 1.06 to 3.25), androstenedione (OR = 2.36, 95% CI = 1.34 to 4.16), and testosterone (OR = 1.91, 95% CI = 1.12 to 3.24). Downstream androgen metabolites were not associated with endometrial cancer. Although increased risks for the parent androgens were still suggested after adjustment for unconjugated estradiol, the associations attenuated, and with the exception of androstenedione, were no longer statistically significant. We also evaluated ratios of estrogens relative to their androgenic precursors; both higher unconjugated estrone:androstenedione and higher unconjugated estradiol:testosterone were associated with increased endometrial cancer risk.

Conclusions

We identified increased risks for endometrial cancer with the highest levels of adrenal androgens and high levels of estrogens relative to these androgens. As adrenal androgens can be aromatized to estrogens, this suggests androgens likely influence endometrial carcinogenesis via estrogen metabolism.

Molecular Modifiers of Hormone Receptor Action: Decreased Androgen Receptor Expression in Mismatch Repair Deficient Endometrial Endometrioid Adenocarcinoma

Endometrial endometrioid carcinoma is related to estrogen excess and expression of estrogen and progesterone receptors. Epidemiological evidence suggests that exposure to elevated androgens, as in polycystic ovarian syndrome, increases the risk of endometrial cancer. Factors impacting androgen receptor (AR) expression are not well studied. Mismatch repair (MMR) deficiency due to MLH1 gene methylation is one of the most common molecular alterations in endometrial cancer, occurring in 15% to 20% of cases. MLH1 methylation can be associated with decreased expression of other genes, so we examined the effect of MMR status on AR expression. As NF-κB is known to induce AR, this transcription factor was also examined. Three hundred forty-four unselected endometrial carcinomas were evaluated for DNA MMR. Loss of expression of MLH1 with MLH1 methylation was defined as MMR deficient, and positive expression of MMR proteins was defined as MMR intact. A case-control cohort of 96 grade 2 endometrioid carcinomas was studied from this set (47 MMR deficient, 49 MMR intact). Cases were matched for histotype, grade, and age. AR and NF-κB immunohistochemical expression were evaluated by 2 different scoring systems (CAP/ASCO and Allred) used for estrogen receptor. Despite higher levels of NF-κB, MMR deficiency was associated with a significantly lower mean percentage of AR expression. The MMR deficient group had more variable AR expression, with more cases scoring on the lower end of the spectrum. These findings have implications for clinical trials of AR antagonists in gynecologic cancers.

Does human endometrial LGR5 gene expression suggest the existence of another hormonally regulated epithelial stem cell niche?

STUDY QUESTION

Is human endometrial leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5) gene expression limited to the postulated epithelial stem cell niche, stratum basalis glands, and is it hormonally regulated?

SUMMARY ANSWER

LGR5 expressing cells are not limited to the postulated stem cell niche but LGR5 expression is hormonally regulated.

WHAT IS KNOWN ALREADY

The human endometrium is a highly regenerative tissue; however, endometrial epithelial stem cell markers are yet to be confirmed. LGR5 is a marker of stem cells in various epithelia.

STUDY DESIGN, SIZE, DURATION

The study was conducted at a University Research Institute. Endometrial samples from 50 healthy women undergoing benign gynaecological surgery with no endometrial pathology at the Liverpool Women's hospital were included and analysed in the following six sub-categories; proliferative, secretory phases of menstrual cycle, postmenopausal, those using oral and local progestagens and samples for in vitro explant culture.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In this study, we used the gold standard method, in situ hybridisation (ISH) along with qPCR and a systems biology approach to study the location of LGR5 gene expression in full thickness human endometrium and Fallopian tubes. The progesterone regulation of endometrial LGR5 was examined in vivo and in short-term cultured endometrial tissue explants in vitro. LGR5 expression was correlated with epithelial proliferation (Ki67), and expression of previously reported epithelia progenitor markers (SOX9 and SSEA-1) immunohistochemistry (IHC).

MAIN RESULTS AND THE ROLE OF CHANCE

LGR5 gene expression was significantly higher in the endometrial luminal epithelium than in all other epithelial compartments in the healthy human endometrium, including the endometrial stratum basalis (P < 0.05). The strongest SSEA-1 and SOX9 staining was observed in the stratum basalis glands, but the general trend of SOX9 and SSEA-1 expression followed the same cyclical pattern of expression as LGR5. Stratum functionalis epithelial Ki67-LI and LGR5 expression levels correlated significantly (r = 0.74, P = 0.01), however, they did not correlate in luminal and stratum basalis epithelium (r = 0.5 and 0.13, respectively). Endometrial LGR5 demonstrates a dynamic spatiotemporal expression pattern, suggesting hormonal regulation. Oral and local progestogens significantly reduced endometrial LGR5 mRNA levels compared with women not on hormonal treatment (P < 0.01). Our data were in agreement with in silico analysis of published endometrial microarrays.

LARGE SCALE DATA

We did not generate our own large scale data but interrogated publically available large scale data sets.

LIMITATIONS, REASONS FOR CAUTION

In the absence of reliable antibodies for human LGR5 protein and validated lineage markers for the various epithelial populations that potentially exist within the endometrium, our study does not formally characterise or examine the functional ability of the resident LGR5+ cells as multipotent.

WIDER IMPLICATIONS OF THE FINDINGS

These data will facilitate future lineage tracing studies in the human endometrial epithelium; to identify the location of stem cells and further complement the in vitro functional studies, to confirm if the LGR5 expressing epithelial cells indeed represent the epithelial stem cell population.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by funding from the Wellbeing of Women project grant (RTF510) and Cancer Research UK (A14895). None of the authors have any conflicts of interest to disclose.

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.