Oestrogen fuels the growth of endometrial hyperplastic lesions initiated by overactive Wnt/β-catenin signalling

Unraveling the Dynamics of Estrogen and Progesterone Signaling in the Endometrium: An Overview

The endometrium is crucial for the perpetuation of human species. It is a complex and dynamic tissue lining the inner wall of the uterus, regulated throughout a woman's life based on estrogen and progesterone fluctuations. During each menstrual cycle, this multicellular tissue undergoes cyclical changes, including regeneration, differentiation in order to allow egg implantation and embryo development, or shedding of the functional layer in the absence of pregnancy. The biology of the endometrium relies on paracrine interactions between epithelial and stromal cells involving complex signaling pathways that are modulated by the variations of estrogen and progesterone levels across the menstrual cycle. Understanding the complexity of estrogen and progesterone receptor signaling will help elucidate the mechanisms underlying normal reproductive physiology and provide fundamental knowledge contributing to a better understanding of the consequences of hormonal imbalances on gynecological conditions and tumorigenesis. In this narrative review, we delve into the physiology of the endometrium, encompassing the complex signaling pathways of estrogen and progesterone.

D-Chiro-Inositol in Endometrial Hyperplasia: A Pilot Study

Endometrial hyperplasia is a threatening pathology driven by unopposed estrogen stimulus. Moreover, insulin may act on the endometrium, prompting further growth. We aimed at assessing whether D-chiro-Inositol, an insulin sensitizer with estrogen-lowering properties, might improve the condition of patients with simple endometrial hyperplasia without atypia. We enrolled women with simple endometrial hyperplasia without atypia and related symptoms, including abnormal uterine bleeding. We treated the patients with one tablet per day, containing 600 mg of D-chiro-inositol for six months. Patients underwent ultrasound to assess the thickness of the endometrium at baseline, after three months, and at the end of this study. Endometrial thickness went from 10.82 ± 1.15 mm to 8.00 ± 0.81 mm after three months (p < 0.001) and to 6.9 ± 1.06 mm after six months (p < 0.001 versus baseline; p < 0.001 versus three months). D-chiro-inositol treatment also improved heavy menstrual bleeding and the length of menstruation. Despite the fact that our data should be validated in larger studies with appropriate control groups, our promising results support the hypothesis that D-chiro-inositol may represent a useful treatment in the case of endometrial hyperplasia without atypia.

Evaluation of sterol‑o‑acyl transferase 1 and cholesterol ester levels in plasma, peritoneal fluid and tumor tissue of patients with endometrial cancer: A pilot study

Endometrial cancer (EC) is the most prevalent gynecological malignancy. Abnormal accumulation of sterol-O-acyl transferase 1 (SOAT1) and SOAT1-mediated cholesterol ester (CE) contributes to cancer progression in various malignancies, including ovarian cancer. Therefore, it was hypothesized that similar molecular changes may occur in EC. The present study aimed to evaluate the diagnostic and/or prognostic potential of SOAT1 and CE in EC by: i) Determining SOAT1 and CE levels in plasma, peritoneal fluid and endometrial tissue from patients with EC and control subjects; ii) performing receiver operating characteristic curve analysis to determine diagnostic performance; iii) comparing SOAT1 and CE expression to that of the tumor proliferation marker Ki67; and iv) assessing the association between SOAT1 expression and survival. Enzyme-linked immunosorbent assay was used to determine the levels of SOAT1 protein in tissue, plasma and peritoneal fluid. The mRNA and protein expression levels of SOAT1 and Ki67 in tissues were detected by reverse transcription-quantitative polymerase chain reaction and immunohistochemistry, respectively. CE levels were determined colorimetrically in plasma and peritoneal fluid. SOAT1-associated survival data from the cBioPortal cancer genomics database were used to assess prognostic relevance. The results revealed that SOAT1 and CE levels were significantly elevated in tumor tissue and peritoneal fluid samples collected from the EC group. By contrast, the plasma levels of SOAT1 and CE in the EC and control groups were similar. Significant positive associations between CE and SOAT1, SOAT1/CE and Ki67, and SOAT1/CE and poor overall survival in patients with EC suggested that SOAT1/CE may be associated with malignancy, aggressiveness and poor prognosis. In conclusion, SOAT1 and CE may serve as potential biomarkers for prognosis and target-specific treatment of EC.

The interplay of sex steroid hormones and microRNAs in endometrial cancer: current understanding and future directions

Introduction

Endometrial cancer is a hormone-dependent malignancy, and sex steroid hormones play a crucial role in its pathogenesis. Recent studies have demonstrated that microRNAs (miRNAs) can regulate the expression of sex steroid hormone receptors and modulate hormone signaling pathways. Our aim is to provide an overview of the current understanding of the role of miRNAs in endometrial cancer regulated by sex steroid hormone pathways.

Methods

A thorough literature search was carried out in the PubMed database. The articles published from 2018 to the present were included. Keywords related to miRNAs, endometrial cancer, and sex steroid hormones were used in the search.

Results

Dysregulation of miRNAs has been linked to abnormal sex steroid hormone signaling and the development of endometrial cancer. Various miRNAs have been identified as modulators of estrogen and progesterone receptor expression, and the miRNA expression profile has been shown to be a predictor of response to hormone therapy. Additionally, specific miRNAs have been implicated in the regulation of genes involved in hormone-related signaling pathways, such as the PI3K/Akt/mTOR and MAPK/ERK pathways.

Conclusion

The regulation of sex steroid hormones by miRNAs is a promising area of research in endometrial cancer. Future studies should focus on elucidating the functional roles of specific miRNAs in sex steroid hormone signaling and identifying novel miRNA targets for hormone therapy in endometrial cancer management.

Loss of HOXA10 causes endometrial hyperplasia progressing to endometrial cancer

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

MicroRNA-133b Inhibits nTumor Cell Proliferation, Migration and Invasion by Targeting SUMO1 in Endometrial Carcinoma

Objectives: An increasing number of studies have confirmed that microRNAs (miRNAs/miRs), as oncogenes or tumor suppressor genes, play an important regulatory role in the occurrence and development of numerous types of cancer. The aim of the present study was to investigate the potential role and mechanism of miR-133b and small ubiquitin like modifier 1 (SUMO1) in the development of endometrial carcinoma (EC). Methods: First, Venn diagrams are used to identify the differential expressions of miRNAs in EC from GSE35794 and GSE25405 datasets. Next, we conduct a series of functional tests, including Cell Counting Kit-8, wound healing, and transwell and matrigel assays. Then, a bioinformatics tool, is used to identify downstream target genes of miR-133b and to verify the predicted results by RT-qPCR, Western blotting and double luciferase reporter gene analysis. Finally, in order to further study whether the cellular function of miR-133b is mediated by the expression of SUMO1, rescue experiments were carried out. Results: The results of bioinformatics studies showed that the expression of miR-133b was down-regulated in EC tissues, and the expression level of miR-133b was lower in patients with high grade, different histology or menopausal status. The results of functional assay showed that overexpression of miR-133b reduced cell proliferation, migration and invasion. On the contrary, miR-133b silence has the opposite effect. SUMO1 was the direct target of miR-133b and was negatively regulated by miR-133b. The decrease of SUMO1mRNA expression inhibited the proliferation, migration and invasion of EC cells, and reversed the effect of miR-133b on EC cells. Conclusion: The findings from the present study suggested that miR-133b may be a tumor suppressor gene and a potential therapeutic target for the treatment of EC.

Gut Microbiota and Gynecological Cancers: A Summary of Pathogenetic Mechanisms and Future Directions

Over the past 20 years, important relationships between the microbiota and human health have emerged. A link between alterations of microbiota composition (dysbiosis) and cancer development has been recently demonstrated. In particular, the composition and the oncogenic role of intestinal bacterial flora has been extensively investigated in preclinical and clinical studies focusing on gastrointestinal tumors. Overall, the development of gastrointestinal tumors is favored by dysbiosis as it leads to depletion of antitumor substances (e.g., short-chain fatty acids) produced by healthy microbiota. Moreover, dysbiosis leads to alterations of the gut barrier, promotes a chronic inflammatory status through activation of toll-like receptors, and causes metabolic and hormonal dysregulations. However, the effects of these imbalances are not limited to the gastrointestinal tract and they can influence gynecological tumor carcinogenesis as well. The purpose of this Review is to provide a synthetic update about the mechanisms of interaction between gut microbiota and the female reproductive tract favoring the development of neoplasms. Furthermore, novel therapeutic approaches based on the modulation of microbiota and their role in gynecological oncology are discussed.

Targeting Wnt Signaling in Endometrial Cancer

Simple Summary

Wnt has diverse regulatory roles at multiple cellular levels and numerous targeting points, and aberrant Wnt signaling has crucial roles in carcinogenesis, metastasis, cancer recurrence, and chemotherapy resistance; based on these facts, Wnt represents an appealing therapeutic target for cancer treatment. Although preclinical data supports a role for the Wnt signaling pathway in uterine carcinogenesis, this area remains understudied. In this review, we identify the functions of several oncogenes of the Wnt/β-catenin signaling pathway in tumorigenesis and address the translation approach with potent Wnt inhibitors that have already been established or are being investigated to target key components of the pathway. Further research is likely to expand the potential for both biomarker and cancer drug development. There is a scarcity of treatment choices for advanced and recurrent endometrial cancer; investigating the sophisticated connections of Wnt signaling networks in endometrial cancer could address the unmet need for new therapeutic targets.

Abstract

This review presents new findings on Wnt signaling in endometrial carcinoma and implications for possible future treatments. The Wnt proteins are essential mediators in cell signaling during vertebrate embryo development. Recent biochemical and genetic studies have provided significant insight into Wnt signaling, in particular in cell cycle regulation, inflammation, and cancer. The role of Wnt signaling is well established in gastrointestinal and breast cancers, but its function in gynecologic cancers, especially in endometrial cancers, has not been well elucidated. Development of a subset of endometrial carcinomas has been attributed to activation of the APC/β-catenin signaling pathway (due to β-catenin mutations) and downregulation of Wnt antagonists by epigenetic silencing. The Wnt pathway also appears to be linked to estrogen and progesterone, and new findings implicate it in mTOR and Hedgehog signaling. Therapeutic interference of Wnt signaling remains a significant challenge. Herein, we discuss the Wnt-activating mechanisms in endometrial cancer and review the current advances and challenges in drug discovery.

Organoids of the Female Reproductive Tract: Innovative Tools to Study Desired to Unwelcome Processes

The pelviperineal organs of the female reproductive tract form an essential cornerstone of human procreation. The system comprises the ectodermal external genitalia, the Müllerian upper-vaginal, cervical, endometrial and oviductal derivatives, and the endodermal ovaries. Each of these organs presents with a unique course of biological development as well as of malignant degeneration. For many decades, various preclinical in vitro models have been employed to study female reproductive organ (patho-)biology, however, facing important shortcomings of limited expandability, loss of representativeness and inadequate translatability to the clinic. The recent emergence of 3D organoid models has propelled the field forward by generating powerful research tools that in vitro replicate healthy as well as diseased human tissues and are amenable to state-of-the-art experimental interventions. Here, we in detail review organoid modeling of the different female reproductive organs from healthy and tumorigenic backgrounds, and project perspectives for both scientists and clinicians.

Endometrial biomarkers in premenopausal women with obesity: an at-risk cohort

BACKGROUND

Obesity is a well-known risk factor for endometrial cancer, but the mechanisms of obesity-related carcinogenesis are not well defined, particularly for premenopausal women. With the continuing obesity epidemic, increases in the incidence of endometrial cancer and a younger age of diagnosis are often attributed to a hyperestrogenic state created by hormone production in adipose tissue, but significant knowledge gaps remain. The balance of estrogen-responsive signals has not been defined in the endometrium of premenopausal women with obesity, where obesity may not create hyperestrogenism in the context of ovaries being the primary source of estrogen production. Obesity is associated with a state of low-grade, chronic inflammation that can promote tumorigenesis, and it is also known that hormonal changes alter the immune microenvironment of the endometrium. However, limited research has been conducted on endometrial immune-response changes in women who have an increased risk for cancer due to obesity.

OBJECTIVE

Endometrial estrogen-regulated biomarkers, previously shown to be dysregulated in endometrial cancer, were evaluated in a cohort of premenopausal women to determine if obesity is associated with differences in the biomarker expression levels, which might reflect an altered risk of developing cancer. The expression of a multiplexed panel of immune-related genes was also evaluated for expression differences related to obesity.

STUDY DESIGN

Premenopausal women with a body mass index of ≥30 kg/m² (n=97) or a body mass index of ≤25 kg/m² (n=33) were prospectively enrolled in this cross-sectional study, which included the assessment of serum metabolic markers and a timed endometrial biopsy for pathologic evaluation, hormone-regulated biomarker analysis, and immune response gene expression analysis. Medical and gynecologic histories were obtained. Endometrial gene expression markers were also compared across the body mass index groups in a previous cohort of premenopausal women with an inherited cancer risk (Lynch syndrome).

RESULTS

In addition to known systemic metabolic differences, histologically normal endometria from women with obesity showed a decrease in gene expression of progesterone receptor (P=.0027) and the estrogen-induced genes retinaldehyde dehydrogenase 2 (P=.008), insulin-like growth factor 1 (P=.016), and survivin (P=.042) when compared with women without obesity. The endometrial biomarkers insulin-like growth factor 1, survivin, and progesterone receptor remained statistically significant in multivariate linear regression models. In contrast, women with obesity and Lynch syndrome had an increased expression of insulin-like growth factor 1 (P=.017). There were no differences in endometrial proliferation, and limited endometrial immune differences were observed.

CONCLUSION

When comparing premenopausal women with and without obesity in the absence of endometrial pathology or an inherited cancer risk, the expression of the endometrial biomarkers does not reflect a local hyperestrogenic environment, but it instead reflects a decreased cancer risk profile that may be indicative of a compensated state. In describing premenopausal endometrial cancer risk, it may be insufficient to attribute a high-risk state to obesity alone; further studies are warranted to evaluate individualized biomarker profiles for differences in the hormone-responsive signals or immune response. In patients with Lynch syndrome, the endometrial biomarker profile suggests that obesity further increases the risk of developing cancer.

Prospective phase II trial of levonorgestrel intrauterine device: nonsurgical approach for complex atypical hyperplasia and early-stage endometrial cancer

BACKGROUND

The incidence of complex atypical hyperplasia and early-stage endometrioid endometrial cancer is increasing, in part owing to the epidemic of obesity, which is a risk factor tightly linked to the development of endometrial hyperplasia and cancer. The standard upfront treatment for complex atypical hyperplasia and early-stage endometrial cancer is hysterectomy. However, nonsurgical treatment of early-stage endometrial neoplasia may be necessary owing to medical comorbidities precluding surgery or desired future fertility.

OBJECTIVE

This study aimed to evaluate the efficacy of the levonorgestrel intrauterine device to treat complex atypical hyperplasia and grade 1 endometrioid endometrial carcinoma.

STUDY DESIGN

A single-institution, single-arm, phase II study of the levonorgestrel intrauterine device (52 mg levonorgestrel, Mirena) was conducted in patients with complex atypical hyperplasia or grade 1 endometrioid endometrial cancer. The primary endpoint was pathologic response rate at 12 months, including complete or partial response. Quality of life and toxicity were assessed. Molecular analyses for proliferation markers, hormone-regulated genes, and wingless-related integration site pathway activation were performed at baseline and 3 months.

RESULTS

A total of 57 patients were treated (21 endometrial cancer, 36 complex atypical hyperplasia). The median age was 48.0 years, and the median body mass index was 45.5 kg/m². Of the 47 evaluable patients, 12-month response rate was 83% (90% credible interval, 72.7-90.3)-37 were complete responders (8 endometrial cancer; 29 complex atypical hyperplasia), 2 were partial responders (2 endometrial cancer), 3 had stable disease (2 endometrial cancer; 1 complex atypical hyperplasia), and 5 had progressive disease (3 endometrial cancer; 2 complex atypical hyperplasia). After stratification for histology, the response rate was 90.6% for complex atypical hyperplasia and 66.7% for grade 1 endometrioid endometrial cancer. Notably, 4 patients (9.5%) experienced relapse after the initial response. Adverse events were mild, primarily irregular bleeding and cramping. Quality of life was not negatively affected. At 3 months, exogenous progesterone effect was present in 96.9% of responders (31 of 32) vs 25% of nonresponders (2 of 8) (P=.001). Nonresponders had higher baseline proliferation (Ki67) and lower dickkopf homolog 3 gene expression than responders (P=.023 and P=.030). Nonresponders had significantly different changes in secreted frizzled-related protein 1, frizzled class receptor 8, and retinaldehyde dehydrogenase 2 compared with responders.

CONCLUSION

The levonorgestrel intrauterine device has a substantial activity in complex atypical hyperplasia and grade 1 endometrioid endometrial cancer, with a modest proportion demonstrating upfront progesterone resistance. Potential biomarkers were identified that may correlate with resistance to therapy; further exploration is warranted.

WNT/β-catenin pathway activation via Wnt1 overexpression and Axin1 downregulation correlates with cadherin-catenin complex disruption and increased lymph node involvement in micropapillary-predominant lung adenocarcinoma

Background

Micropapillary-predominant adenocarcinoma (MPA) of the lung is associated with extensive lymph node involvement and rapid terminal metastasis. However, this subtype has been recognized for only a few years, and there have been few studies of the molecular mechanisms associated with its highly invasive behaviors.

Methods

The present study utilized immunohistochemical staining of surgically resected tissue blocks of MPA and lepidic-predominant lung adenocarcinoma to quantify the expression of specific biological markers in the WNT/β-catenin pathway and evaluate their influence on the lymph nodes invasion of these two types of lung adenocarcinomas.

Results

Our findings revealed that disruption of the cell membrane cadherin-catenin complex, which weakens the tumor cell adherence of MPA, was caused by the dissociation of β-catenin from the cadherin-catenin complex and the subsequent accumulation of β-catenin in the cytoplasm. This caused abnormal activation of the WNT/β-catenin pathway. We also found that Wnt-1-specific overexpression and Axin1 inhibition in MPA could explain the redistribution and cytoplasmic retention of β-catenin. Collectively, these findings suggest that an abnormality in the WNT/β-catenin pathway could enhance the invasiveness of MPA through the overexpression of Wnt-1 and downregulation of Axin1 molecules.

Conclusions

Our data support the need for further research regarding the WNT/β-catenin pathway and the need to develop novel targeted therapies for restoration of tumor cell adherence and improvement of the prognosis of MPA.

Changes in subsets of immunocytes in endometrial hyperplasia

PROBLEM

Endometrial hyperplasia (EH) is characterized by an endometrial gland-to-stroma ratio >1 and is one of the most common gynecological diseases in the world. The role of immunocyte subsets in the development of EH remains unknown.

METHODS

Patients who underwent dilatation and curettage due to abnormal uterine bleeding were recruited in the present study. Alterations in the numbers of different types of immune cell subsets in the endometrium of patients were analyzed by flow cytometry.

RESULTS

The present study included 48 patients who were divided into three groups, based on the pathological results: (a) proliferative period (PP, n = 12); (b) simple EH (SEH, n = 30); and (c) complex EH (CEH, n = 6). The results showed that immune cell subpopulations were significantly different between these three groups. Compared with the PP group, the proportion of CD45⁺ cells and neutrophils and the subtypes of T cells and macrophages were significantly increased in the SEH patients. Compared with the PP and SEH groups, subsets of immunocytes in the CEH group were significantly decreased, including the population of CD45⁺ cells and the subtypes of T cells and natural killer cells; in contrast, the proportion of macrophages was significantly increased. There were no significant differences between the other cell subsets in each group.

CONCLUSION

The changes in immune cell subsets may be closely associated with the progression of EH. Although the specific role of different immune cell subsets in the development of the diseases requires further study, the changes in the proportions of immune cell subsets should not be ignored.

Wnt Signaling in Gynecologic Malignancies

Gynecologic malignancies, including ovarian cancer, endometrial cancer, and cervical cancer, affect hundreds of thousands of women worldwide every year. Wnt signaling, specifically Wnt/β-catenin signaling, has been found to play an essential role in many oncogenic processes in gynecologic malignancies, including tumorigenesis, metastasis, recurrence, and chemotherapy resistance. As such, the Wnt/β-catenin signaling pathway has the potential to be a target for effective treatment, improving patient outcomes. In this review, we discuss the evidence supporting the importance of the Wnt signaling pathways in the development, progression, and treatment of gynecologic malignancies.

Cyclooxygenase-2 and β-Catenin as Potential Diagnostic and Prognostic Markers in Endometrial Cancer

Objectives: Explore the diagnostic and prognostic value of cyclooxygenase-2 and wnt3a/β-catenin pathway in endometrial cancer.

Methods: A prospective cohort study of 93 women underwent hysterectomy at the China-Japan Friendship Hospital (61 patients with primary endometrial carcinoma, and 32 control patients with uterine prolapse or leiomyoma of uterus). Cox2 and β-catenin expression were determined by immunohistochemistry. The serum levels of cox2 and wnt3a were detected via ELISA assays.

Results: Patients with endometrial cancer showed overexpression of cox2 and β-catenin, as well as significantly higher serum levels of cox2 and wnt3a. The serum cox2 level, which is highly significant in predicting the risk of disease progression (RR, 9.617, 95% confidence interval, 1.162–79.622, P = 0.036), showed good diagnostic and prognostic potential, with cut-off of 55 U/L, but alongside β-catenin expression in tissues, were related to poor prognosis (RR, 12.426; 95% confidence interval, 1.618–95.450; P = 0.015).

Conclusion: Serum levels of cox2 and wnt3a exhibited diagnostic value for endometrial cancer. Cox2 serum levels and β-catenin expression also showed potential value of prognostic prediction. Cox2 serum levels might be a potential marker for early diagnosis and prognosis prediction in endometrial cancer.

Crosstalk of estrogen receptors and Wnt/β-catenin signaling in endometrial cancer

PURPOSE

To investigate the interaction between Wnt/β-catenin and estrogen signaling pathways in endometrial cancer (EC).

METHODS

119 women were involved in this study, including 65 women with histologically confirmed EC and 54 healthy women as a control group. Serum protein levels of Dkk1 were measured using ELISA. Protein expression levels of Dkk1, β-catenin, ER-β isoforms (β1, β2, β5), and ER-α were tested in paraffin-embedded tissues using IHC. Gene expression levels of Dkk1, CTNNB, ESR1, and ESR2 were tested in fresh tumorous and normal endometrium tissues using RT-PCR.

RESULTS

EC patients had significantly higher serum levels of Dkk1 protein compared with healthy women. Dkk1 and β-catenin showed different expression pattern in tumor cells compared to it in normal cells at the protein level but not at the gene level. Protein expression levels of ERβ2 and ERα were significantly lower in tumor cells compared with tumor-adjacent normal cells. Increased protein expression levels of ERα were associated with favorable clinicopathological features and better overall survival rate (OS). Protein expression levels of ERα were correlated with protein expression levels of Dkk1 and cytoplasmic β-catenin. The association between ERα expression levels and OS was no more significant when tested in regard to Dkk1- and cytoplasmic β-catenin expression levels.

CONCLUSIONS

Our data demonstrated that Wnt/β-catenin and estrogen signaling systems are dysregulated in EC showing; for the first time, a potential crosstalk between certain components of these two pathways, which in turn has affected the specificity of these molecules in disease characteristics. Understanding the signaling networks in EC is crucial in designing clinical trials to evaluate the efficacy of molecular-targeted agents and providing more successful therapies in the future.