Activation of a positive feedback loop involving IL-6 and aromatase promotes intratumoral 17β-estradiol biosynthesis in endometrial carcinoma microenvironment

17β-estradiol biosensors based on different bioreceptors and their applications

17β-Estradiol (E2) is a critical sex steroid hormone, which has significant effects on the endocrine systems of both humans and animals. E2 is also believed to play neurotrophic and neuroprotective roles in the brain. Biosensors present a powerful tool to detect E2 because of their small, efficient, and flexible design. Furthermore, Biosensors can quickly and accurately obtain detection results with only a small sampling amount, which greatly meets the detection of the environment, food safety, medicine safety, and human body. This review focuses on previous studies of biosensors for detecting E2 and divides them into non-biometric sensors, enzyme biosensors, antibody biosensors, and aptamer biosensors according to different bioreceptors. The advantages, disadvantages, and design points of various bioreceptors for E2 detection are analyzed and summarized. Additionally, applications of different bioreceptors of E2 detection are presented and highlight the field of environmental monitoring, food and medicine safety, and disease detection in recent years. Finally, the development of E2 detection by biosensor is prospected.

The Relationship between Time, Race, and Estrogen Receptor Alpha in Estradiol-Induced Dermal Fibrosis

In the skin, estradiol (E2) promotes profibrotic and proinflammatory cytokines, contributing to extracellular matrix (ECM) deposition. However, the magnitude of the response differs. Using the human skin organ culture model, we evaluated donor characteristics and correlations that contribute to E2-induced interleukin-6 (IL-6), transforming growth factor beta 1 and 2 (TGFB1 and TGFB2), collagen IA2 (Col IA2), collagen IIIA1 (Col IIIA1), and fibronectin (FN) expressions. In vehicle- and E2-treated dermal skin tissue transcripts, we confirm differences in the magnitude; however, there were positive correlations between profibrotic mediators and ECM components 48 h after E2 treatment. Also, positive correlations exist between baseline and E2-induced TGFB1, IL-6, Col IIIA1, and FN transcripts. Since estrogen receptor alpha (ERA) can propagate E2's signal, we measured and detected differences in its baseline and fold change transcript levels, with a significant decline in baseline levels 48 h after incubation and an increase 48 h after E2 treatment. There was a trend to higher transcript levels in African American donors 24 h earlier. Finally, E2-induced ERA transcript levels negatively correlated with its own baseline levels and positively correlated with FN, TGFB1, and Col IA2 transcript levels. Therefore, our data suggest ERA, E2 exposure time, and race/ethnicity contribute to E2-induced dermal fibrosis.

Sex hormones and the total testosterone:estradiol ratio as predictors of severe acute respiratory syndrome coronavirus 2 infection in hospitalized men

BACKGROUND

The predictive ability of the early determination of sex steroids and the total testosterone:estradiol ratio for the risk of severe coronavirus disease 2019 or the potential existence of a biological gradient in this relationship has not been evaluated.

OBJECTIVES

To assess the relationship of sex steroid levels and the total testosterone:estradiol ratio with the risk of severe acute respiratory syndrome coronavirus 2 infection in men, defined as the need for intensive care unit admission or death, and the predictive ability of each biomarker.

MATERIALS AND METHODS

This was a prospective observational study. We included all consecutive adult men with severe acute respiratory syndrome coronavirus 2 infections in a single center admitted to a general hospital ward or to the intensive care unit. Sex steroids were evaluated at the centralized laboratory of our hospital.

RESULTS

We recruited 98 patients, 54 (55.1%) of whom developed severe coronavirus disease in 2019. Compared to patients with nonsevere coronavirus disease 2019, patients with severe coronavirus disease 2019 had significantly lower serum levels of total testosterone (111 ± 89 vs. 191 ± 143 ng/dL; p < 0.001), dehydroepiandrosterone (1.69 ± 1.26 vs. 2.96 ± 2.64 ng/mL; p < 0.001), and dehydroepiandrosterone sulfate (91.72 ± 76.20 vs. 134.28 ± 98.261 μg/dL; p = 0.009), significantly higher levels of estradiol (64.61 ± 59.35 vs. 33.78 ± 13.78 pg/mL; p = 0.001), and significantly lower total testosterone:estradiol ratio (0.28 ± 0.31 vs. 0.70 ± 0.75; p < 0.001). The lower the serum level of androgen and the lower the total testosterone:estradiol ratio values, the higher the likelihood of developing severe coronavirus disease 2019, with the linear trend in the adjusted analyses being statistically significant for all parameters except for androstenedione (p = 0.064). In the receiver operating characteristic analysis, better predictive performance was shown by the total testosterone:estradiol ratio, with an area under the curve of 0.77 (95% confidence interval 0.68-0.87; p < 0.001).

DISCUSSION AND CONCLUSION

Our results suggest that men with severe acute respiratory syndrome coronavirus 2 infection, decreased androgen levels and increased estradiol levels have a higher likelihood of developing an unfavorable outcome. The total testosterone:estradiol ratio showed the best predictive ability.

Roles of estrogen receptor α in endometrial carcinoma (Review)

Endometrial carcinoma (EC) is a group of endometrial epithelial malignancies, most of which are adenocarcinomas and occur in perimenopausal and postmenopausal women. It is one of the most common carcinomas of the female reproductive system. It has been shown that the occurrence and development of EC is closely associated with the interaction between estrogen (estradiol, E2) and estrogen receptors (ERs), particularly ERα. As a key nuclear transcription factor, ERα is a carcinogenic factor in EC. Its interactions with upstream and downstream effectors and co-regulators have important implications for the proliferation, metastasis, invasion and inhibition of apoptosis of EC. In the present review, the structure of ERα and the regulation of ERα in multiple dimensions are described. In addition, the classical E2/ERα signaling pathway and the crosstalk between ERα and other EC regulators are elucidated, as well as the therapeutic targeting of ERα, which may provide a new direction for clinical applications of ERα in the future.

Interplay between Estrogen, Kynurenine, and AHR Pathways: An immunosuppressive axis with therapeutic potential for breast cancer treatment

Breast cancer is one of the most common malignancies among women worldwide. Estrogen exposure via endogenous and exogenous sources during a lifetime, together with environmental exposure to estrogenic compounds, represent the most significant risk factor for breast cancer development. As breast tumors establish, multiple pathways are deregulated. Among them is the aryl hydrocarbon receptor (AHR) signaling pathway. AHR, a ligand-activated transcription factor associated with the metabolism of polycyclic aromatic hydrocarbons and estrogens, is overexpressed in breast cancer. Furthermore, AHR and estrogen receptor (ER) cross-talk pathways have been observed. Additionally, the Tryptophan (Trp) catabolizing enzymes indolamine-2,3-dioxygenase (IDO) and tryptophan-2,3-dioxygenase (TDO) are overexpressed in breast cancer. IDO/TDO catalyzes the formation of Kynurenine (KYN) and other tryptophan-derived metabolites, which are ligands of AHR. Once KYN activates AHR, it stimulates the expression of the IDO enzyme, increases the level of KYN, and activates non-canonical pathways to control inflammation and immunosuppression in breast tumors. The interplay between E2, AHR, and IDO/TDO/KYN pathways and their impact on the immune system represents an immunosuppressive axis on breast cancer. The potential modulation of the immunosuppressive E2-AHR-IDO/TDO/KYN axis has aroused great expectations in oncotherapy. The present article will review the mechanisms implicated in generating the immunosuppressive axis E2-AHR-IDO/TDO/KYN in breast cancer and the current state of knowledge as a potential therapeutic target.

Landscape of PCOS co-expression gene and its role in predicting prognosis and assisting immunotherapy in endometrial cancer

BACKGROUND

Endometrial carcinoma (EC) is the sixth most frequent malignancy in women and is often linked to high estrogen exposure. Polycystic ovarian syndrome (PCOS) is a known risk factor for EC, but the underlying mechanisms remain unclear.

METHODS

We investigated shared gene signals and potential biological pathways to identify effective therapy options for PCOS- and EC-related malignancies. Weighted gene expression network analysis (WGCNA) was used to identify genes associated with PCOS and EC using gene expression data from the Gene Expression Omnibus (GEO) and Cancer Genome Atlas (TCGA) datasets. Enrichment analysis using Cluego software revealed that the steroid hormone biosynthetic process was a critical feature in both PCOS and EC. A predictive signature encompassing genes involved in steroid hormone production was developed using multivariate and least absolute shrinkage and selection operator (LASSO) regression analysis to predict the prognosis of EC. Then, we conducted further experimental verification.

RESULTS

Patients in the TCGA cohort with high predictive scores had poorer outcomes than those with low scores. We also investigated the relationship between tumor microenvironment (TME) features and predictive risk rating and found that patients with low-risk scores had higher levels of inflammatory and inhibitory immune cells. Also, we found that immunotherapy against anti-CTLA4 and anti-PD-1/PD-L1 was successful in treating individuals with low risk. Low-risk individuals were more responsive to crizotinib therapy, according to further research performed using the "pRRophetic" R package. We further confirmed that IGF2 expression was associated with tumor cell migration, proliferation, and invasion in EC cells.

CONCLUTIONS

By uncovering the pathways and genes linking PCOS and EC, our findings may provide new therapeutic strategies for patients with PCOS-related EC.

The roles and clinical applications of interleukins in endometrial carcinoma

As a common malignant tumor of the female reproductive system, endometrial carcinoma (EC) seriously endangers women's health with an increasing incidence. The oncogenesis and progression of cancer are closely linked with immune microenvironment, of which interleukins are the important components. In order to illustrate the roles and clinical applications of interleukins in EC, literature of interleukins and EC were reviewed. Based on the present studies, interleukins play crucial roles in the oncogenesis and development of EC via regulating the proliferation, migration, invasion, angiogenesis, apoptosis, pyroptosis and autophagy of EC as well as the immune function against EC. And some of the interleukins seems to have prospective clinical applications in EC, such as evaluating the risk of tumorigenesis, discriminating the malignancy from benign disorders or normal condition, indicating cancer aggressiveness, predicting the prognosis of patients and serving as the novel therapy. However, there is still a long way to go before the clinical applications of interleukins in EC come into reality. Nevertheless, it is certain that the exploration of interleukins will definitely be of great benefit to the screening, diagnosis and treatment of EC in the future.

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.

Gut and Endometrial Microbiome Dysbiosis: A New Emergent Risk Factor for Endometrial Cancer

Endometrial cancer is one of the most common gynaecological malignancies worldwide. Histologically, two types of endometrial cancer with morphological and molecular differences and also therapeutic implications have been identified. Type I endometrial cancer has an endometrioid morphology and is estrogen-dependent, while Type II appears with non-endometrioid differentiation and follows an estrogen-unrelated pathway. Understanding the molecular biology and genetics of endometrial cancer is crucial for its prognosis and the development of novel therapies for its treatment. However, until now, scant attention has been paid to environmental components like the microbiome. Recently, due to emerging evidence that the uterus is not a sterile cavity, some studies have begun to investigate the composition of the endometrial microbiome and its role in endometrial cancer. In this review, we summarize the current state of this line of investigation, focusing on the relationship between gut and endometrial microbiome and inflammation, estrogen metabolism, and different endometrial cancer therapies.

Macrophage Immune Memory Controls Endometriosis in Mice and Humans

Endometriosis is a frequent, chronic, inflammatory gynecological disease characterized by the presence of ectopic endometrial tissue causing pain and infertility. Macrophages have a central role in lesion establishment and maintenance by driving chronic inflammation and tissue remodeling. Macrophages can be reprogrammed to acquire memory-like characteristics after antigenic challenge to reinforce or inhibit a subsequent immune response, a phenomenon termed "trained immunity." Here, whereas bacille Calmette-Guérin (BCG) training enhances the lesion growth in a mice model of endometriosis, tolerization with repeated low doses of lipopolysaccharide (LPS^low) or adoptive transfer of LPS^low-tolerized macrophages elicits a suppressor effect. LPS^low-tolerized human macrophages mitigate the fibro-inflammatory phenotype of endometriotic cells in an interleukin-10 (IL-10)-dependent manner. A history of severe Gram-negative infection is associated with reduced infertility duration and alleviated symptoms, in contrast to patients with Gram-positive infection history. Thus, the manipulation of innate immune memory may be effective in dampening hyper-inflammatory conditions, opening the way to promising therapeutic approaches.

HPV-16/18 E6-induced APOBEC3B expression associates with proliferation of cervical cancer cells and hypomethylation of Cyclin D1

Oncogenic high-risk human papillomavirus (HR-HPV) infection causes a majority of cases of cervical cancer and pre-cancerous cervical lesions. However, the mechanisms underlying the direct evolution from HPV-16/18-infected epithelium to cervical intraepithelial neoplasia (CIN) III, which can progress to cervical cancer, remain poorly identified. Here, we performed RNA-seq after laser capture microdissection, and found that APOBEC3B was highly expressed in cervical cancer specimens compared with CIN III with HPV-16/18 infection. Furthermore, immunohistochemical analysis confirmed that high levels of APOBEC3B were correlated with lymph node metastasis in cervical cancer. Subsequent experiments revealed that HPV-16 E6 could upregulate APOBEC3B through direct binding to the promoter of APOBEC3B in cervical cancer cells. Silencing of APOBEC3B by stable short hairpin RNA-mediated knockdown reduced the proliferative capacity of Caski and HeLa cells in vitro and in vivo, but had only a small effect on the migration and invasion of two cervical cancer cell lines. Finally, we identified the changes in gene expression following APOBEC3B silencing in Caski cells by microarray, demonstrating a biological link between APOBEC3B and CCND1 in cervical cancer cells. Importantly, through methyl-capture sequencing and pyrosequencing, APOBEC3B was found to affect the levels of the downstream protein Cyclin D1 (which is encoded by the CCND1 gene) through hypomethylation of the CCND1 promoter. In conclusion, our study supports HPV-16 E6-induced APOBEC3B expression associates with proliferation of cervical cancer cells and hypomethylation of Cyclin D1. Thus, APOBEC3B may be a potential therapeutic target in human cervical cancer.

Expression of IL17A in endometrial carcinoma and effects of IL17A on biological behaviour in Ishikawa cells

Objective

A growing body of evidence suggests chronic inflammation triggers the process of endometrial carcinogenesis. Interleukin (IL) 17A is an important proinflammatory factor involved in the tumour angiogenesis processes of many solid tumours. This study aimed to characterize the function of IL17A in endometrioid-type endometrial carcinoma.

Methods

Levels of IL17A in human endometrial tissues were analysed by immunohistochemistry. In vitro proliferation and migration were analysed in Ishikawa cells treated with IL17A, using cell counting kit-8, wound healing and transwell assays. Western blots were used to analyse levels of oestrogen receptor (ER)α and ERβ proteins in Ishikawa cells treated with IL17A.

Results

IL17A levels were significantly higher in endometrial carcinoma tissues than in endometrial hyperplasic tissues. Significantly increased proliferation and migration was observed in Ishikawa cells treated with IL17A versus controls. Investigation of the molecular mechanism revealed that IL17A treatment upregulated the ERα/ERβ protein ratio in Ishikawa cells.

Conclusions

IL17A may be an important proinflammatory factor involved in promoting endometrial carcinogenesis.

Estrogen-ERα signaling and DNA hypomethylation co-regulate expression of stem cell protein PIWIL1 in ERα-positive endometrial cancer cells

Background

We previously identified PIWIL1 as an oncogene involved in endometrial carcinogenesis. However, the mechanism of Piwil1 mediated regulation of tumorigenesis remains poorly understood.

Methods

The expression levels of target genes in endometrial cancer cells were detected by quantitative reverse transcription-PCR (RT-qPCR) and western blotting. Up- or down-regulation of ERα or PIWIL1 was achieved by transient transfection with expressing plasmids or short hairpin RNA (shRNA). Dual-luciferase reporter assays and chromatin immunoprecipitation (ChIP) were used to demonstrate the ERα bound to the half estrogen response element (half-ERE) located in PIWIL1 promoter. The expression of PIWIL1 and ERα in endometrial carcinoma tissues were investigated using immunohistochemistry and RT-qPCR. The proliferation ability of cancer cells were evaluated by MTT. Methylation status of the PIWIL1 promoter was detected by bisulfite sequencing PCR (BSP).

Results

In the present study, we found that PIWIL1 mediated E₂-stimulated cancer cell proliferation. In ERα-positive endometrial cancer cells, we demonstrated that estrogen-ERα signaling significantly up-regulated the expression of PIWIL1, which was mediated by binding of the ERα onto the PIWIL1 promoter. Furthermore, we found that a half-ERE in the PIWIL1 promoter was essential for ERα binding. The PIWIL1 promoter was hypomethylated in ERα-positive endometrial cancer cells. Treatment with 5-aza-deoxycytidine (5-aza-dC) could up-regulate PIWIL1 expression.

Conclusions

These findings uncover a novel molecular mechanism by which estrogen-ERα signaling and DNA hypomethylation co-regulate PIWIL1 expression. These findings provide novel insights into the hormonal regulation of PIWIL1 in endometrial cancer and the PIWIL1’s role in estrogen-stimulated endometrial carcinogenesis.

Sexual dimorphism in SARS-COV-2 infection

Previous studies have demonstrated that female patients with coronavirus disease 2019 (COVID-19) demonstrate more favorable prognosis relative to male patients. In this article, we elaborate the possible role of estrogen in the modulation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection severity. The potential interplay between several factors, including inherently lower estradiol (E₂) and slightly higher estrogen receptor β (ERβ) levels in males, with inflammatory mediators are described. Altogether, there seems to be a sexually dimorphic response towards SARS-CoV-2 infection, and a possibility that COVID-19 severity is dependent on both E₂ levels and ERα:ERβ expression ratio in lymphoid and lung cells.

The Role of Metabolic Syndrome in Endometrial Cancer: A Review

Endometrial cancer is one of the most common cancers of the female reproductive system. Although surgery, radiotherapy, chemotherapy, and hormone therapy can significantly improve the survival of patients, the treatment of patients with very early lesions and a strong desire to retain reproductive function or late recurrence is still in the early stages. Metabolic syndrome (MS) is a clustering of at least three of the five following medical conditions: central obesity, high blood pressure, high blood sugar, high serum triglycerides, and low serum high-density lipoprotein (HDL). Obesity, diabetes and hypertension often coexist in patients with endometrial cancer, which increases the risk of endometrial cancer, also known as the "triple syndrome of endometrial cancer." In recent years, epidemiological and clinical studies have found that MS associated with metabolic diseases is closely related to the incidence of endometrial cancer. However, the key molecular mechanisms underlying the induction of endometrial cancer by MS have not been elucidated to date. Characterizing the tumor metabolism microenvironment will be advantageous for achieving a comprehensive view of the molecular mechanism of metabolic syndrome associated with endometrial cancer and for providing a new target for the treatment of endometrial cancer. This review focuses on recent advances in determining the role of metabolic syndrome-related factors and mechanisms in the pathogenesis of endometrial cancer. We suggest that interfering with the tumor metabolic microenvironment-related molecular signals may inhibit the occurrence of endometrial cancer.

Hormonal Regulation of Patient-Derived Endometrial Cancer Stem-like Cells Generated by Three-Dimensional Culture

Low-grade and early-stage endometrial cancer usually has a favorable prognosis, whereas recurrent or metastatic disease is often difficult to cure. Thus, the molecular mechanisms underlying advanced pathophysiology remain to be elucidated. From the perspective of the origin of advanced endometrial cancer, the characterization of cancer stem-like cells (CSCs) will be the first step toward the development of clinical management. We established long-term culturable patient-derived cancer cells (PDCs) from patient endometrial tumors by spheroid cell culture, which is favorable for the enrichment of CSCs. PDC-derived xenograft tumors were generated in immunodeficient NOD/Shi-scid, IL-2RγKO Jic mice. Morphologically, PDCs derived from three distinct patient samples and their xenograft tumors recapitulated the corresponding original patient tumors. Of note, CSC-related genes including ALDH1A1 were upregulated in all of these PDCs, and the therapeutic potentiality of aldehyde dehydrogenase inhibitors was demonstrated. In addition, these PDCs and their patient-derived xenograft (PDX) models exhibited distinct characteristics on the basis of their hormone responsiveness and metastatic features. Interestingly, genes associated with inflammation and tumor immunity were upregulated by 17β-estradiol in PDC lines with high estrogen receptor expression and were also overexpressed in secondary PDCs obtained from metastatic tumor models. These results suggest that PDC and PDX models from endometrial cancer specimens would be useful to elucidate CSC traits and to develop alternative diagnostic and therapeutic options for advanced disease.

IL-6/p-BTK/p-ERK signaling mediates calcium phosphate-induced pruritus

Uremic pruritus with elevated levels of calcium phosphate (CaP) in skin is a common symptom in patients with chronic kidney disease (CKD). In this study, we demonstrate that intradermal injection of CaP into mice triggered scratching by up-regulating the IL-6 in skin and phosphorylation of ERKs in dorsal root ganglion (DRG) in a dose-dependent manner. IL-6 is essential because the CaP-induced up-regulation of phosphorylated (p)-ERK in DRG was considerably reduced in the IL-6 knockout mice. Microarray analysis in conjunction with real-time PCR revealed a higher mRNA expression of Bruton's tyrosine kinase (BTK) gene in DRG after CaP injection. The inhibition of BTK by ibrutinib noticeably diminish the CaP-induced up-regulation of IL-6 and p-ERK in mice. A high amount of IL-6 was detected in itchy skin and blood of patients with CKD. The expressions of p-BTK and p-ERK in DRG primary cells reached maximum levels at 1 and 10 min, respectively, after treatment of recombinant IL-6 and were significantly reduced by treatment of IL-6 along with ibrutinib. The mechanism by which the CaP-induced pruritus mediated by the IL-6/p-BTK/p-ERK signaling was revealed.-Keshari, S., Sipayung, A. D., Hsieh, C.-C., Su, L.-J., Chiang, Y.-R., Chang, H.-C., Yang, W.-C., Chuang, T.-H., Chen, C.-L., Huang, C.-M. IL-6/p-BTK/p-ERK signaling mediates calcium phosphate-induced pruritus.

17β-Estradiol promotes endometrial cancer proliferation and invasion through IL-6 pathway

Accumulating evidence revealed that the leading risk factor of endometrial cancer is exposure to endogenous and exogenous estrogens, while the exact mechanism underlying estrogen contribution to endometrial cancer progression has not been elucidated clearly. Interleukin (IL)-6 has been verified to be critical for tumor progression in several human cancers. In this study, we provided evidence that 17β-estradiol (E2) could significantly promote endometrial cancer cells viability, migration and invasion through activation of IL-6 pathway, which involved in its downstream pathway and target genes (p-Stat3, Bcl-2, Mcl-1, cyclin D1 and MMP2). Meanwhile, utilization of IL-6-neutralizing antibody could partially attenuate the increased cancer growth and invasion abilities in Ishikawa and RL95-2 endometrial cancer cell lines and an orthotopic endometrial cancer model. We established a causative link between estrogen and IL-6 signaling activation in the development of endometrial cancer. The molecular mechanism defined in this study provided the evidence that E2 promotes endometrial carcinoma progression via activating the IL-6 pathway, indicating that interruption of IL-6 might be an essential therapeutic strategy in estrogen-dependent endometrial cancer.

IL-6 promotes endometrial cancer cells invasion and migration through signal transducers and activators of transcription 3 signaling pathway

Interleukin (IL)-6 is the most well-known traditional activator of activating signal transducers and activators of transcription 3 (Stat3). They have been proved to promote cancer progression in several human cancers. However, their exact roles in endometrial cancer have not been elucidated clearly. In this study, we aimed to investigate the role of IL-6/Stat3 signaling pathway in human endometrial cancer cells invasion and migration. We demonstrated that Stat3 is activated in endometrial cancer cell lines. To investigate the role of Stat3 in endometrial cancer invasive capacity, we used Stat3 inhibitor Stattic and found that Stattic significantly inhibited the migration and invasion of endometrial cancer cells elevated by IL-6. Furthermore, we showed that Stat3 inhibitor significantly decreased the expression of MMP2 enhanced by IL-6, indicating that IL-6 promoted endometrial cancer invasion and migration by Stat3-induced MMP2 upregulation. Taken together, our findings indicate that targeting IL-6/Stat3 pathway might be a potentially effective therapeutic strategy for treating endometrial cancer.

Genetics of IL6 polymorphisms: Case-control study of the risk of endometrial cancer

Background

Endometrial cancer is the most common gynaecological malignancy. Cytokines gene may be important in endometrial cancer development. This study sought to investigate whether the IL4, IL6 two gene genetic variants were associated with susceptibility to endometrial cancer (EC) in Hainan Chinese Han women by a hospital‐based study.

Methods

The genetic polymorphisms for IL4 and IL6 were analyzed by Agena MassARRAY method. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by unconditional logistic regression.

Results

We observed a significant increase in risk of endometrial cancer of rs1524107 (IL6) (T/C, OR = 1.61, 95% CI = 1.09–2.37, p = 1.55 × 10⁻²), rs2066992 (IL 6) (OR = 3.09, 95% CI = 2.11–4.53, p = 3.13 × 10⁻⁹). However, for IL4 gene, no associations emerged the SNP and EC risk.

Conclusion

This study demonstrated that IL6 gene polymorphisms are significantly associated with increased EC susceptibility in Hainan Chinese Han women.

The Emerging Role of the Microenvironment in Endometrial Cancer

Endometrial cancer (EC) is one of the most frequently diagnosed cancers in women, and despite recent therapeutic advances, in many cases, treatment failure results in cancer recurrence, metastasis, and death. Current research demonstrates that the interactive crosstalk between two discrete cell types (tumor and stroma) promotes tumor growth and investigations have uncovered the dual role of the stromal cells in the normal and cancerous state. In contrast to tumor cells, stromal cells within the tumor microenvironment (TME) are genetically stable. However, tumor cells modify adjacent stromal cells in the TME. The alteration in signaling cascades of TME from anti-tumorigenic to pro-tumorigenic enhances metastatic potential and/or confers therapeutic resistance. Therefore, the TME is a fertile ground for the development of novel therapies. Furthermore, disrupting cancer-promoting signals from the TME or re-educating stromal cells may be an effective strategy to impair metastatic progression. Here, we review the paradoxical role of different non-neoplastic stromal cells during specific stages of EC progression. We also suggest that the inhibition of microenvironment-derived signals may suppress metastatic EC progression and offer novel potential therapeutic interventions.

Development of an Image-Guided Orthotopic Xenograft Mouse Model of Endometrial Cancer with Controllable Estrogen Exposure

Endometrial cancer (EC) is the most common gynaecological malignancy in Western society and the majority of cases are estrogen dependent. While endocrine drugs proved to be of insufficient therapeutic value in the past, recent clinical research shows promising results by using combinational regimens and pre-clinical studies and identified potential novel endocrine targets. Relevant pre-clinical models can accelerate research in this area. In the present study we describe an orthotopic and estrogen dependent xenograft mouse model of EC. Tumours were induced in one uterine horn of female athymic nude mice using the well-differentiated human endometrial adenocarcinoma Ishikawa cell line—modified to express the luciferase gene for bioluminescence imaging (BLI). BLI and contrast-enhanced computed-tomograph (CE-CT) were used to measure non-invasive tumour growth. Controlled estrogen exposure was achieved by the use of MedRod implants releasing 1.5 μg/d of 17β-estradiol (E2) in ovariectomized mice. Stable E2 serum concentration was demonstrated by LC-MS/MS. Induced tumours were E2 responsive as increased tumour growth was observed in the presence of E2 but not placebo, assessed by BLI, CE-CT, and tumour weight at sacrifice. Metastatic spread was assessed macroscopically by BLI and histology and was seen in the peritoneal cavity, in the lymphovascular space, and in the thoracic cavity. In conclusion, we developed an orthotopic xenograft mouse model of EC that exhibits the most relevant features of human disease, regarding metastatic spread and estrogen dependency. This model offers an easy to manipulate estrogen dosage (by simply adjusting the MedRod implant length), image-guided monitoring of tumour growth, and objectively measurable endpoints (including tumour weight). This is an excellent in vivo tool to further explore endocrine drug regimens and novel endocrine drug targets for EC.

Prostaglandin E2 triggers cytochrome P450 17α hydroxylase overexpression via signal transducer and activator of transcription 3 phosphorylation and promotes invasion in endometrial cancer

Prostaglandin E2 (PGE2) is the most common prostaglandin in the human body, meaning that its malfunction impacts on the development of numerous diseases. Prostaglandin E synthase 2 (PTGES2) is involved in the synthesis of PGE2. In the present study, immunohistochemistry of PTGES2 was performed in 152 patients with endometrial cancer and in 66 patients with normal endometria. The results indicate a notable association among increased expression of PTGES2 and age (P=0.0092) and the depth of myometrial invasion (P<0.0001). Reverse transcription-quantitative polymerase chain reaction and western blot analysis demonstrated that cytochrome P450 17α hydroxylase (CYP17), an enzyme for androgen synthesis, is overexpressed following PGE2 stimulation via signal transducer and activator of transcription 3 (STAT3) phosphorylation. ELISA also detected increased androgen (testosterone) secretion. Further invasion of endometrial cancer cells was induced at high androgen levels and when CYP17 was overexpressed. Furthermore, the present study observed that CYP17 is overexpressed via STAT3 phosphorylation in endometrial cancer cells, which grow at a high concentration of PGE2, resulting in increased androgen secretion. Concentrations of estrogen and progesterone were not elevated, while the concentration of androgens was. Overall, a high concentration of androgens caused increased invasion of endometrial cancer cells. A high concentration of androgens, which is initiated by a high expression of PTGES2 and a high concentration of PGE2, is an important promoter of myometrial invasion in endometrial cancer.

17β-estradiol upregulates IL6 expression through the ERβ pathway to promote lung adenocarcinoma progression

Background

In non-small cell lung cancer (NSCLC), estrogen (E2) significantly promotes NSCLC cell growth via estrogen receptor beta (ERβ). Discovery and elucidation of the mechanism underlying estrogen-promoted NSCLC progression is critical for effective preventive interventions. IL6 has been demonstrated to be involved in the development, progression and metastasis in several cancers and IL6 overexpression is associated with poor prognosis in NSCLC. However, the exact role played by IL6 in estrogen-promoted NSCLC progress remain unknown. Here, we evaluated the expression and biological effects of IL6 in NSCLC cells when treated with E2 and explored the underlying mechanism of IL6 in E2-promoted NSCLC progression.

Methods

Expression of ERβ/IL6 in 289 lung cancer samples was assessed by immunohistochemistry. Matched samples of metastatic lymph node and primary tumor tissues were used to quantify the expression of ERβ/IL6 by western blot. Expression levels of IL6 in NSCLC cells were quantified by western blotting, ELISA, and immunofluorescence staining. The effects of IL6 stimulated by E2 on cell malignancy were evaluated using CCK8, colony formation, wound healing and transwell. Furthermore, overexpression and knockdown ERβ constructs were constructed to measure the expression of IL6. The effects of IL6 stimulated by E2 on tumor growth were evaluated using a urethane-induced adenocarcinoma model. In addition, a xenograft mouse model was used to observe differences in ERβ subtype tumor growth with respect to IL6 expression.

Results

IL6/ERβ expression were significantly increased in lung cancer. Higher IL6/ERβ expression was associated with decreased differentiation or increased metastasis. IL6 was an independent prognostic factor for overall survival (OS), higher IL6 expression was associated with decreased OS. Furthermore, ERβ regulates IL6 expression via MAPK/ERK and PI3K/AKT pathways when stimulated by E2 and promotes cell malignancy in vitro and induced tumor growth in vivo. Finally we confirm that ERβ isolation 1/5 is essential for E2 promotion of IL6 expression, while ERβ2 not.

Conclusions

Our findings demonstrate that E2 stimulates IL6 expression to promote lung adenocarcinoma progression through the ERβ pathway. We also clarify the difference in each ERβ subtype for E2 promoting IL6 expression, suggesting that ERβ/IL6 might be potential targets for prognostic assessment and therapeutic intervention in lung cancer.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0804-5) contains supplementary material, which is available to authorized users.

Metformin inhibits stromal aromatase expression and tumor progression in a rodent model of postmenopausal breast cancer

BACKGROUND

Obesity and type II diabetes are linked to increased breast cancer risk in postmenopausal women. Patients treated with the antidiabetic drug metformin for diabetes or metabolic syndrome have reduced breast cancer risk, a greater pathologic complete response to neoadjuvant therapy, and improved breast cancer survival. We hypothesized that metformin may be especially effective when targeted to the menopausal transition, as this is a lifecycle window when weight gain and metabolic syndrome increase, and is also when the risk for obesity-related breast cancer increases.

METHODS

Here, we used an 1-methyl-1-nitrosourea (MNU)-induced mammary tumor rat model of estrogen receptor (ER)-positive postmenopausal breast cancer to evaluate the long-term effects of metformin administration on metabolic and tumor endpoints. In this model, ovariectomy (OVX) induces rapid weight gain, and an impaired whole-body response to excess calories contributes to increased tumor glucose uptake and increased tumor proliferation. Metformin treatment was initiated in tumor-bearing animals immediately prior to OVX and maintained for the duration of the study.

RESULTS

Metformin decreased the size of existing mammary tumors and inhibited new tumor formation without changing body weight or adiposity. Decreased lipid accumulation in the livers of metformin-treated animals supports the ability of metformin to improve overall metabolic health. We also found a decrease in the number of aromatase-positive, CD68-positive macrophages within the tumor microenvironment, suggesting that metformin targets the immune microenvironment in addition to improving whole-body metabolism.

CONCLUSIONS

These findings suggest that peri-menopause/menopause represents a unique window of time during which metformin may be highly effective in women with established, or at high risk for developing, breast cancer.

A role for G-protein coupled estrogen receptor (GPER) in estrogen-induced carcinogenesis: Dysregulated glandular homeostasis, survival and metastasis

Mechanisms of carcinogenesis by estrogen center on its mitogenic and genotoxic potential on tumor target cells. These models suggest that estrogen receptor (ER) signaling promotes expansion of the transformed population and that subsequent accumulation of somatic mutations that drive cancer progression occur via metabolic activation of cathecol estrogens or by epigenetic mechanisms. Recent findings that GPER is linked to obesity, vascular pathology and immunosuppression, key events in the development of metabolic syndrome and intra-tissular estrogen synthesis, provides an alternate view of estrogen-induced carcinogenesis. Consistent with this concept, GPER is directly associated with clinicopathological indices that predict cancer progression and poor survival in breast and gynecological cancers. Moreover, GPER manifests cell biological responses and a microenvironment conducive for tumor development and cancer progression, regulating cellular responses associated with glandular homeostasis and survival, invading surrounding tissue and attracting a vascular supply. Thus, the cellular actions attributed to GPER fit well with the known molecular mechanisms of G-protein coupled receptors, GPCRs, namely, their ability to transactivate integrins and EGF receptors and alter the interaction between glandular epithelia and their extracellular environment, affecting epithelial-to-mesenchymal transition (EMT) and allowing for tumor cell survival and dissemination. This perspective reviews the molecular and cellular responses manifested by GPER and evaluates its contribution to female reproductive cancers as diseases that progress as a result of dysregulated glandular homeostasis resulting in chronic inflammation and metastasis. This review is organized in sections as follows: I) a brief synopsis of the current state of knowledge regarding estrogen-induced carcinogenesis, II) a review of evidence from clinical and animal-based studies that support a role for GPER in cancer progression, and III) a mechanistic framework describing how GPER-mediated estrogen action may influence the tumor and its microenvironment.

Risk factors for ovarian involvement in young and premenopausal endometrioid endometrial cancer patients

OBJECTIVE

This study aimed to investigate the incidence of ovarian malignant involvement in young and premenopausal endometrioid endometrial cancer and study the possible risk factors.

METHODS

Premenopausal patients 45 years of age or younger with endometrioid endometrial cancer treated at the OB/GYN Hospital of Fudan University between 2009 and 2013 were identified. The incidence of ovarian malignant involvement in young and premenopausal endometrioid endometrial cancer patients were calculated and the possible risk factors were investigated.

RESULTS

A total of 144 younger (age ≤ 45, premenopausal) patients with endometrioid endometrial cancer were identified and coexisting malignant ovarian neoplasms were detected in 6 patients. Univariate analysis revealed that deeper myometrial invasion, positive lymphonode metastasis, positive LVSI, and high histologic grade (G2-G3) were associated with ovarian involvement in younger endometrial cancer patients. However, multivariate analysis revealed that only deep myometrial invasion was an independent risk factors for ovarian involvement (OR = 12.81, P = 0.046).

CONCLUSION

In conclusions, the incidence of coexisting ovarian malignant neoplasms in young and premenopausal patients with endometrioid endometrial cancer is low, and these findings may facilitate preoperative counseling of patients and decision making at the time of surgery.

Estrogen and high-fat diet induced alterations in C57BL/6 mice endometrial transcriptome profile

Unopposed estrogen stimulation and insulin resistance are known to play important roles in endometrial cancer (EC), but the interaction between these two factors and how they contribute to endometrial lesions are not completely elucidated. To investigate the endometrial transcriptome profile and the associated molecular pathway alterations, we established an ovariectomized C57BL/6 mouse model treated with subcutaneous implantation of 17-β estradiol (E2) pellet and/or high-fat diet (HFD) for 12 weeks to mimic sustained estrogen stimulation and insulin resistance. Histomorphologically, we found that both E2 and E2 + HFD groups showed markedly enlarged uterus and increased number of endometrial glands. The endometrium samples were collected for microarray assay. GO and KEGG analysis showed that genes regulated by E2 and/or HFD are mainly responsible for immune response, inflammatory response and metabolic pathways. Further IPA analysis demonstrated that the acute phase response signaling, NF-κB signaling, leukocyte extravasation signaling, PPAR signaling and LXR/RXR activation pathways are mainly involved in the pathways above. In addition, the genes modulated reciprocally by E2 and/or HFD were also analyzed, and their crosstalk mainly focuses on enhancing one another's activity. The combination analysis of microarray data and TCGA database provided potential diagnostic or therapeutic targets for EC. Further validation was performed in mice endometrium and human EC cell lines. In conclusion, this study unraveled the endometrial transcriptome profile alterations affected by E2 and/or HFD that may disturb endometrial homeostasis and contribute to the development of endometrial hyperplasia.

Reciprocal crosstalk between endometrial carcinoma and mesenchymal stem cells via transforming growth factor-β/transforming growth factor receptor and C-X-C motif chemokine ligand 12/C-X-C chemokine receptor type 4 aggravates malignant phenotypes

Designated for cyclic shedding, the endometrial stroma is rich in endometrial mesenchymal stem cells (EMSCs) and may play an important role in the development of endometrial carcinoma (EC). This study characterized the crosstalk of EC cells with EMSCs and the resultant effects on malignant phenotypes. The cultured EMSCs expressed CD73, CD90, and CD105, but not CD14, CD19, CD34, CD45, or human leukocyte antigen—antigen D related markers. These EMSCs also showed osteogenic, adipogenic, and chondrogenic differentiation ability. Transforming growth factor (TGF)-β1 and C–X–C motif chemokine ligand 12 (CXCL12) secretion or expression were reciprocally enhanced in EC cells and EMSCs, as well as in their tissues. By acting on the receptors expressed in their mutual target cells, the interaction between TGF-β and CXCL12 results in the enhanced migration, invasion, tumorigenesis, and epithelial–mesenchymal transition of EC cells, which can be blocked by neutralizing the antibody of either CXCL12 or C–X–C chemokine receptor type 4. The study revealed unprecedented paracrine interactions between EC cells and EMSCs that resulted in the enhancement of transformation phenotypes. Thus, the blocking of TGF-β or CXCL12 signaling can be a therapeutic target for EC.

EFEMP1 is repressed by estrogen and inhibits the epithelial-mesenchymal transition via Wnt/β-catenin signaling in endometrial carcinoma

Epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) acted as a tumor suppressor in endometrial carcinoma (EC). However, the correlation between EFEMP1 and estrogen is unknown. Here, we reported that the expression of EFEMP1 was conversely associated with ERα in endometrial carcinoma tissues. In endometrial carcinoma cells, estrogen/ERα signaling significantly suppressed the expression of EFEMP1. Moreover, chromatin immunoprecipitation (CHIP) and dual-luciferase reporter assays demonstrate that estrogen/ERα bound to the estrogen response element (ERE) located in EFEMP1 promoter and repressed its expression. Besides, in vitro and in vivo, EFEMP1 could remarkably suppress the expression of epithelial-mesenchymal transition (EMT) markers such as Vimentin, Snail and the Wnt/β-catenin target genes like Cyclin-D1 and c-Myc, which could be restored when EFEMP1 was silenced. In addition, XAV93920 (the inhibitor of the Wnt/β-catenin pathway) blocked and LiCl (the activator of the Wnt/β-catenin pathway) enhanced the effect of EFEMP1 on EMT. In conclusion, we demonstrated that estrogen/ERα signal suppresses EFEMP1. Besides, EFEMP1 inhibits EMT via interfering the Wnt/β-catenin signaling.

Estrogen Stimulation Differentially Impacts Human Male and Female Antigen-Specific T Cell Anti-Tumor Function and Polyfunctionality

Sex-specific differences exist in innate and adaptive immune responses and are mediated by hormone signaling. Estrogen is able to differentially modulate the development and differentiation of immune cells, including T cells. However, the effect of estrogen on T cell function, especially at concentrations other than physiological, remains controversial and incompletely understood. Immunotherapy is one of the most promising cancer treatments to date with a high probability of future enhancements. The adoptive transfer of genetically modified T cells can mediate tumor regression but there are still many hurdles to enhancing the proficiency of this treatment. This study demonstrates for the first time that one major aspect to consider for designing potent immunotherapies for cancer is the impact of the patient's sex. Herein, using two different Ag-specific T cell groups, we investigated the effect of sex and estrogen in antitumor effector responses, T helper cytokine secretion, and, importantly, on T cell whole polyfunctionality important for memory T cell development and survival. Major differences were observed in T cell function and polyfunctionality between sexes and on E2 treatment. The findings of this study may be critical to understand the results of immunotherapy on different patients and for the enhancement of immunotherapy for cancer.

Aspirin use and endometrial cancer risk and survival

The role of acetylsalicylic acid (aspirin) as a chemo-preventive and adjuvant therapeutic agent for cancers is generating attention. Mounting evidence indicates that aspirin reduces the incidence and mortality of certain obesity-related cancers, particularly colorectal cancer. In endometrial cancer, previous studies examining the effect of aspirin remain inconsistent as to the reduction in the risk of endometrial cancer. While some evidence indicates protective effects in obese women, other studies have showed a potential deleterious effect of these medications on endometrial cancer outcomes. However, exposure measurement across studies has been inconsistent in recording dose, duration, and frequency of use; thus making comparisons difficult. In this article, we review the evidence for the association between endometrial cancer and obesity, the pharmacological differences between regular- and low-dose aspirin, as well as the potential anti-tumor mechanism of aspirin, supporting a possible therapeutic effect on endometrial cancer. A proposed mechanism behind decreased cancer mortality in endometrial cancer may be a result of inhibition of metastasis via platelet inactivation and possible prostaglandin E₂ suppression by aspirin. Additionally, aspirin use in particular may have a secondary benefit for obesity-related comorbidities including cardiovascular disease in women with endometrial cancer. Although aspirin-related bleeding needs to be considered as a possible adverse effect, the benefits of aspirin therapy may exceed the potential risk in women with endometrial cancer. The current evidence reviewed herein has resulted in conflicting findings regarding the potential effect on endometrial cancer outcomes, thus indicating that future studies in this area are needed to resolve the effects of aspirin on endometrial cancer survival, particularly to identify specific populations that might benefit from aspirin use.

Cross-talk between p21-activated kinase 4 and ERα signaling triggers endometrial cancer cell proliferation

Cross-talk between estrogen receptor alpha (ERα) and signal transduction pathways plays an important role in the progression of endometrial cancer (EC). Here, we show that 17β-estradiol (E₂) stimulation increases p21-activated kinase 4 (Pak4) expression and activation in ER-positive EC cells. The estrogen-induced Pak4 activation is mediated via the PI3K/AKT pathway. Estrogen increases Pak4 and phosphorylated-Pak4 (p-Pak4) nuclear accumulation, and Pak4 in turn enhances ERα trans-activation. Depletion or functional inhibition of Pak4 abrogates EC cell proliferation induced by E₂, whereas overexpression of Pak4 rescues cell proliferation decreased by inhibiting the estrogen pathway. Pak4 knockdown decreases cyclin D1 expression and induces G1-S arrest. Importantly, Pak4 suppression inhibits E₂ induced EC tumor growth in vivo, in a mouse xenograft model. These data demonstrate that estrogen stimulation increases Pak4 expression and activation, which in turn enhances ERα transcriptional activity and ERα-dependent gene expression, resulting in increased proliferation of EC cells. Thus inhibition of Pak4-ERα signaling may represent a novel therapeutic strategy against endometrial carcinoma.

STAT5 deletion in macrophages alters ductal elongation and branching during mammary gland development

Macrophages are required for proper mammary gland development and maintaining tissue homeostasis. However, the mechanisms by which macrophages regulate this process remain unclear. Here, we identify STAT5 as an important regulator of macrophage function in the developing mammary gland. Analysis of mammary glands from mice with STAT5-deficient macrophages demonstrates delayed ductal elongation, enhanced ductal branching and increased epithelial proliferation. Further analysis reveals that STAT5 deletion in macrophages leads to enhanced expression of proliferative factors such as Cyp19a1/aromatase and IL-6. Mechanistic studies demonstrate that STAT5 binds directly to the Cyp19a1 promoter in macrophages to suppress gene expression and that loss of STAT5 results in enhanced stromal expression of aromatase. Finally, we demonstrate that STAT5 deletion in macrophages cooperates with oncogenic initiation in mammary epithelium to accelerate the formation of estrogen receptor (ER)-positive hyperplasias. These studies establish the importance of STAT5 in macrophages during ductal morphogenesis in the mammary gland and demonstrate that altering STAT5 function in macrophages can affect the development of tissue-specific disease.

Supervised Clustering of Adipokines and Hormonal Receptors Predict Prognosis in a Population of Obese Women with Type 1 Endometrial Cancer

Obesity is a major risk factor for endometrial cancer (EC). Yet, its impact on prognosis is controversial. Obesity is associated with metabolic and hormonal dysregulation as well as adipokines increase. The aim of this study was to characterize the expression of biological factors related to obesity within the tumor and evaluate their impact on prognosis. One hundred and thirty-six patients, including 55 obese patients, with endometrioid type I EC operated by total hysterectomy were included in this retrospective study conducted in a Tertiary teaching hospital between 2000 and 2013. Immunohistochemistry (IHC) study was performed on type I EC tumor samples using five adipokines (SPARC, RBP4 (Retinol Binding Protein 4), adiponectin, TNF α, IL-6) and hormonal receptors (estrogen receptor and progesterone receptor). Supervised clustering of immunohistochemical markers was performed to identify clusters that could be associated with prognostic groups. The prognosis of the obese population was not different from the prognosis of the general population. Adipokine expression within tumors was not different in these two populations. In obese population, we found three clusters where co-expression was associated with a recurrence group in comparison with a non-recurrence group and four clusters where co-expression was associated with the high risk FIGO (International Federation of Gynecology and Obstetrics) stage I group in comparison of low risk FIGO stage I group. While obesity does not appear as a prognostic factor in endometrioid type I EC, the co-expression of biological factors in IHC on hysterectomy specimens allowed to distinguish two prognostic groups in obese population.

FOXO3, estrogen receptor alpha, and androgen receptor impact tumor growth rate and infiltration of dendritic cell subsets differentially between male and female mice

Tumors evade immune recognition and destruction in many ways including the creation of an immune-suppressive tumor microenvironment (TME). Dendritic cells (DC) that infiltrate the TME are tolerogenic, and suppress effector T cells and anti-tumor activity. Previous reports demonstrated that a key regulator of tolerance in DC is the transcription factor FOXO3. Gender disparity has been studied in cancer in relation to incidence, aggressiveness, and prognosis. Few studies have touched on the importance in relation to impact on the immune system. In the current study, we show that there are significant differences in tumor growth between males and females. Additionally, frequencies and the function of FOXO3 expressed by DC subsets that infiltrate tumors vary between genders. Our results show for the first time that DC FOXO3 expression and function is altered in females. In vitro results indicate that these differences may be the result of exposure to estrogen. These differences may be critical considerations for the enhancement of immunotherapy for cancer.

Transition into inflammatory cancer-associated adipocytes in breast cancer microenvironment requires microRNA regulatory mechanism

The role of adipocytes in cancer microenvironment has gained focus during the recent years. However, the characteristics of the cancer-associated adipocytes (CAA) in human breast cancer tissues and the underlying regulatory mechanism are not clearly understood. We reviewed pathology specimens of breast cancer patients to understand the morphologic characteristics of CAA, and profiled the mRNA and miRNA expression of CAA by using indirect co-culture system in vitro. The CAAs in human breast cancers showed heterogeneous topographic relationship with breast cancer cells within the breast microenvironment. The CAAs exhibited the characteristics of de-differentiation determined by their microscopic appearance and the expression levels of adipogenic markers. Additionally, the 3T3-L1 adipocytes indirectly co-cultured with breast cancer cells showed up-regulation of inflammation-related genes including Il6 and Ptx3. The up-regulation of IL6 in CAA was further observed in human breast cancer tissues. miRNA array of indirectly co-cultured 3T3-L1 cells showed increased expression of mmu-miR-5112 which may target Cpeb1. Cpeb1 is a negative regulator of Il6. The suppressive role of mmu-miR-5112 was confirmed by dual luciferase reporter assay, and mmu-miR-5112-treated adipocytes showed up-regulation of Il6. The transition of adipocytes into more inflammatory CAA resulted in proliferation-promoting effect in ER positive breast cancer cells such as MCF7 and ZR-75-1 but not in ER negative cells. In this study, we have determined the de-differentiated and inflammatory natures of CAA in breast cancer microenvironment. Additionally, we propose a miRNA-based regulatory mechanism underlying the process of acquiring inflammatory phenotypes in CAA.

Increased TET1 Expression in Inflammatory Microenvironment of Hyperinsulinemia Enhances the Response of Endometrial Cancer to Estrogen by Epigenetic Modulation of GPER

Background: Insulin resistance (IR) has been well studied in the initiation and development of endometrial endometrioid carcinoma (EEC). As yet, it has been largely neglected for estrogen sensitivity in local endometrium in hyperinsulinemia-induced systemic microenvironment. The aim of this study was to investigate the role of insulin in regulating estrogen sensitivity and explore the potential mechanisms in insulin-driven inflammatory microenvironment.

Methods: We first investigated the effect of insulin on estradiol-driven endometrial cancer cells proliferation in vitro to address the roles of insulin in modulating estrogen sensitivity. Then GPER, ERα and TET1 in EEC samples with or without insulin resistance were screened by immunohistochemistry to confirm whether insulin resistance regulates estrogen receptors. Further mechanism analysis was carried out to address whether TET1 was mediated epigenetic modulation of GPER in insulin-induced microenvironment.

Results: Insulin enhanced estradiol-driven endometrial cancer cells proliferation by up-regulating G-protein-coupled estrogen receptor (GPER) expression, but not ERα or ERβ. Immunohistochemistry of EEC tissues showed that GPER expression was greatly increased in endometrial tissues from EEC subjects with insulin resistance and was positively correlated with Ten-eleven-translocation 1 (TET1) expression. Mechanistically, insulin up-regulates TET1 expression, and the latter, an important DNA hydroxymethylase, could up-regulate GPER expression through epigenetic modulation.

Conclusion: This study identified TET1 as the upstream regulator of GPER expression and provides a possible mechanism that insulin-induced positive regulation of estrogen sensitivity in endometrial cancer cells. Increasing expression of GPER through TET1-mediated epigenetic modulation may emerge as the main regulator to enhance the response of endometrial cancer to estrogen in insulin-driven inflammatory microenvironment.

Dysregulation of Aromatase in Breast, Endometrial, and Ovarian Cancers: An Overview of Therapeutic Strategies

Aromatase is the rate-limiting enzyme in the biosynthesis of estrogens, which play crucial roles on a spectrum of developmental and physiological processes. The biological actions of estrogens are classically mediated by binding to two estrogen receptors (ERs), ERα and ERβ. Encoded by the cytochrome P450, family 19, subfamily A, polypeptide 1 (CYP19A1) gene, aromatase is expressed in a wide variety of tissues, as well as benign and malignant tumors, and is regulated in a pathway- and tissue-specific manner. Overexpression of aromatase, leading to elevated systemic levels of estrogen, is unequivocally linked to the pathogenesis and growth of a number malignancies, including breast, endometrium, and ovarian cancers. Aromatase inhibitors (AIs) are routinely used to treat estrogen-dependent breast cancers in postmenopausal women; however, their roles in endometrial and ovarian cancers remain obscure. While AI therapy is effective in hormone sensitive cancers, they diminish estrogen production throughout the body and, thus, generate undesirable side effects. Despite the effectiveness of AI therapy, resistance to endocrine therapy remains a major concern and is the leading cause of cancer death. Considerable advances, toward mitigating these issues, have evolved in conjunction with a number of histone deacetylase (HDAC) inhibitors for countering an assortment of diseases and cancers, including the aforesaid malignancies. HDACs are a family of enzymes that are frequently dysregulated in human tumors. This chapter will discuss the current understanding of aberrant regulation and expression of aromatase in breast, endometrial, and ovarian cancers, and potential therapeutic strategies for prevention and treatment of these life-threatening diseases.

N,N-Dimethylacetamide Significantly Attenuates LPS- and TNFα-Induced Proinflammatory Responses Via Inhibition of the Nuclear Factor Kappa B Pathway

Previously, we have shown that N,N-dimethylacetamide (DMA) prevents inflammation-induced preterm birth in a murine model, inhibits LPS-induced increases in placental pro-inflammatory cytokines and up-regulates the anti-inflammatory cytokine Interleukin-10 (IL-10). However, DMA's mechanism of action remains to be elucidated. In the current study we investigate how DMA produces its anti-inflammatory effect. Using in vitro and ex vivo models, we show that DMA suppresses secretion of pro-inflammatory cytokines in lipopolysaccharide (LPS)-induced RAW 264.7 cells, TNFα-challenged JEG-3 cells and LPS-stimulated human placental explants. DMA significantly attenuated the secretion of TNFα, IL-6, IL-10, and granulocyte macrophage colony stimulating factor (GM-CSF) from LPS-stimulated RAW 264.7 cells, IL-6 secretion from TNFα-stimulated JEG-3 cells and TNFα, IL-6, IL-10, GM-CSF and Interleukin-8 (IL-8) from LPS-stimulated human placental explants. We further investigated if DMA's effect on cytokine expression involves the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. DMA (10 mM) significantly inhibited nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) degradation in LPS-stimulated RAW 264.7 cells, but there was no significant change in the expression of phosphorylated or native forms of downstream proteins in the MAPK pathway. In addition, DMA significantly attenuated luciferase activity in cells co-transfected with NF-κB-Luc reporter plasmid, but not with AP-1-Luc or CEBP-Luc reporters. Overall, our findings suggest that the anti-inflammatory activity of DMA is mediated by inhibition of the NF-κB pathway via decreased IκBα degradation.

In situ androgen and estrogen biosynthesis in endometrial cancer: focus on androgen actions and intratumoral production

In situ estrogen biosynthesis is considered to play pivotal roles in the development and progression of human endometrial carcinoma. However, the biological roles of androgen have remained virtually unknown. Various epidemiological studies have revealed that elevated serum androgen levels are generally associated with an increased risk of developing endometrial carcinoma; however, studies directly examining androgens in carcinoma tissues are relatively rare and reviews summarizing this information are scarce. Therefore, we summarized recent studies on androgens in endometrial carcinoma, especially focusing androgen actions and in situ androgen biosynthesis. Among the enzymes required for local biosynthesis of androgen, 17β-hydroxysteroid dehydrogenase type 5 (conversion from androstenedione to testosterone) and 5α-reductase (reduction of testosterone to dihydrotestosterone (DHT)) are the principal enzymes involved in the formation of biologically most potent androgen, DHT. Both enzymes and androgen receptor were expressed in endometrial carcinoma tissues, and in situ production of DHT has been reported to exist in endometrial carcinoma tissues. However, testosterone is not only a precursor of DHT production, but also a precursor of estradiol synthesis, as a substrate of the aromatase enzyme. Therefore, aromatase could be another key enzyme serving as a negative regulator for in situ production of DHT by reducing amounts of the precursor. In an in vitro study, DHT was reported to exert antiproliferative effects on endometrial carcinoma cells. Intracrine mechanisms of androgens, the downstream signals of AR, which are directly related to anticancer progression, and the clinical significance of DHT-AR pathway in the patients with endometrial carcinoma have, however, not been fully elucidated.

Prostaglandin E2 (PGE2) promotes proliferation and invasion by enhancing SUMO-1 activity via EP4 receptor in endometrial cancer

Prostaglandin E2 (PGE2), a derivative of arachidonic acid, has been identified as a tumorigenic factor in many cancers in recent studies. Prostaglandin E synthase 2 (PTGES2) is an enzyme that in humans is encoded by the PTGES2 gene located on chromosome 9, and it synthesizes PGE2 in human cells. In our study, we selected 119 samples from endometrial cancer patients, with 50 normal endometrium tissue samples as controls, in which we examined the expression of PTGES2. Both immunohistochemistry (IHC) and Western blot analyses demonstrated that synthase PTGES2, which is required for PGE2 synthesis, was highly expressed in endometrium cancer tissues compared with normal endometrium. Stable PTGES2-shRNA transfectants were generated in Ishikawa and Hec-1B endometrial cancer cell lines, and transfection efficiencies were confirmed by RT-PCR and Western blot analyses. We found that PGE2 promoted proliferation and invasion of cells in Ishikawa and Hec-1B cells by cell counting kit-8 tests (CCK8) and transwell assays, respectively. PGE2 stimulation enhanced the expression of SUMO-1, via PGE2 receptor subtype 4 (EP4). Further analysis implicated the Wnt/β-catenin signaling pathway function as the major mediator of EP4 and SUMO-1. The increase in SUMO-1 activity prompted the SUMOlyation of target proteins which may be involved in proliferation and invasion. These findings suggest SUMO-1 and EP4 as two potential targets for new therapeutic or prevention strategies for endometrial cancers.

Tumor-associated macrophage-derived CXCL8 could induce ERα suppression via HOXB13 in endometrial cancer

PURPOSE

To elucidate the role of tumor-associated macrophage (TAM) in the loss of ERα in endometrial cancer (EC) and the underlying mechanism.

MATERIALS AND METHODS

Tissue microarrays and immunohistochemistry assays were performed using endometrial cancer tissue along with coculture, immunofluorescence, invasion assays and ChIP-qPCR using a human endometrial cancer cell line.

RESULTS

Compared with normal tissue, an increased number of TAM was found in EC tissue (34.0 ± 2.6 vs. 8.3 ± 1.1, respectively; p < 0.001), which may downregulate ERα (27.4%, p < 0.05 for HEC-1A and 16.9%, p < 0.05 for Ishikawa) and promote EC cell invasion (1.8-fold, p < 0.001 for HEC-1A and 2.0-fold, p < 0.001 for Ishikawa). Furthermore, we found that TAM-derived CXCL8 mediated the loss of ERα and cancer invasion via HOXB13. HOXB13 was highly expressed in the ERα-negative subtype (r = -0.204, p = 0.002) and low expression of ESR1 was associated with a poor prognosis for EC patients (log-rank p < 0.05).

CONCLUSION

TAM-secreted CXCL8 downregulated the ERα expression of EC cells via HOXB13, which may be associated with cancer invasion, metastasis and poor prognosis.

Cancer development, chemoresistance, epithelial to mesenchymal transition and stem cells: A snapshot of IL-6 mediated involvement

Interleukin-6 (IL-6) is a cytokine present in tumor microenvironment. Elevated level of IL-6 is associated with cancer cell proliferation, angiogenesis and metastasis through fueling STAT3, MAPK and Akt signaling. It promotes epithelial to mesenchymal transition (EMT) through altered expression of N-cadherin, vimentin, snail, twist and E-cadherin leading to cancer metastasis. IL-6 boosts mammosphere formation, self-renewal of stem cells, stemness properties of cancer cells and recruitment of mesenchymal stem cells. IL-6 is also a contributing factor for multidrug resistance in cancer due to gp130/MAPK/STAT3 mediated activation of transcription factors C/EBPβ/δ, overexpression of p-glycoprotein, EMT transition and expansion of stem cells. The in-depth investigation of IL-6 mediated cellular effects and its signaling pathway can provide the new window for future research and clinical development of IL-6 targeted therapy in cancer. Thus, an overview is delivered in this review deciphering the emerging aspect of the predominant influence of IL-6 in malignant transformation, EMT, cancer-associated stem cells and chemoresistance.

Macrophages: Regulators of the Inflammatory Microenvironment during Mammary Gland Development and Breast Cancer

Macrophages are critical mediators of inflammation and important regulators of developmental processes. As a key phagocytic cell type, macrophages evolved as part of the innate immune system to engulf and process cell debris and pathogens. Macrophages produce factors that act directly on their microenvironment and also bridge innate immune responses to the adaptive immune system. Resident macrophages are important for acting as sensors for tissue damage and maintaining tissue homeostasis. It is now well-established that macrophages are an integral component of the breast tumor microenvironment, where they contribute to tumor growth and progression, likely through many of the mechanisms that are utilized during normal wound healing responses. Because macrophages contribute to normal mammary gland development and breast cancer growth and progression, this review will discuss both resident mammary gland macrophages and tumor-associated macrophages with an emphasis on describing how macrophages interact with their surrounding environment during normal development and in the context of cancer.

Multimodal Imaging of Orthotopic Mouse Model of Endometrial Carcinoma

BACKGROUND

Orthotopic endometrial cancer models provide a unique tool for studies of tumour growth and metastatic spread. Novel preclinical imaging methods also have the potential to quantify functional tumour characteristics in vivo, with potential relevance for monitoring response to therapy.

METHODS

After orthotopic injection with luc-expressing endometrial cancer cells, eleven mice developed disease detected by weekly bioluminescence imaging (BLI). In parallel the same mice underwent positron emission tomography-computed tomography (PET-CT) and magnetic resonance imaging (MRI) employing 18F-fluorodeoxyglocose (18F-FDG) or 18F- fluorothymidine (18F-FLT) and contrast reagent, respectively. The mice were sacrificed when moribund, and post-mortem examination included macroscopic and microscopic examination for validation of growth of primary uterine tumours and metastases. PET-CT was also performed on a patient derived model (PDX) generated from a patient with grade 3 endometrioid endometrial cancer.

RESULTS

Increased BLI signal during tumour growth was accompanied by increasing metabolic tumour volume (MTV) and increasing MTV x mean standard uptake value of the tumour (SUVmean) in 18F-FDG and 18F-FLT PET-CT, and MRI conspicuously depicted the uterine tumour. At necropsy 82% (9/11) of the mice developed metastases detected by the applied imaging methods. 18F-FDG PET proved to be a good imaging method for detection of patient derived tumour tissue.

CONCLUSIONS

We demonstrate that all imaging modalities enable monitoring of tumour growth and metastatic spread in an orthotopic mouse model of endometrial carcinoma. Both PET tracers, 18F-FDG and 18F-FLT, appear to be equally feasible for detecting tumour development and represent, together with MRI, promising imaging tools for monitoring of patient-derived xenograft (PDX) cancer models.

Establishment of a novel cell-based assay for screening small molecule antagonists of human interleukin-6 receptor

AIM

Blockade of interleukin-6 (IL-6) or its receptor (IL-6R) is effective in preventing the progression of autoimmune diseases, such as systemic lupus erythematosus and rheumatoid arthritis. In the present study, we established a novel cell-based assay for identifying small molecule IL-6R antagonists.

METHODS

HEK293A cells were transfected with recombinant plasmids pTaglite-SNAP-IL6R and pABhFc-IL6 to obtain membrane-bound IL-6R and recombinant human IL-6 coupled with human Fc fragment (rhIL-6), respectively. A novel screening assay based on the interaction between IL-6R and rhIL-6 was established, optimized and validated. The stability of the assay was also assessed by calculating the Z'-factor.

RESULTS

RhIL-6 dose-dependently bound to IL-6R expressed at HEK293A cell surface. The IC50 value of the known antagonist ab47215 was 0.38±0.08 μg/mL, which was consistent with that obtained using the traditional method (0.36±0.14 μg/mL). The value of Z'-factor was 0.68, suggesting that the novel assay was stable for high throughput screening. A total of 474 compounds were screened using the novel screening assay, and 3 compounds exhibited antagonistic activities (IC50=8.73±0.28, 32.32±9.08, 57.83±4.24 μg/mL). Furthermore, the active compounds dose-dependently inhibited IL-6-induced proliferation of 7TD1 cells, and reduced IL-6-induced STAT3 phosphorylation in U937 cells.

CONCLUSION

A novel cell-based screening assay for identifying small molecule IL-6R antagonists was established, which simplifies the procedures in traditional cellular ELISA screening and profiling and reduces the costs.