Selective estrogen receptor modulators (SERMs): a review of clinical data

The vitamin D analog EB1089 sensitizes triple-negative breast cancer cells to the antiproliferative effects of antiestrogens

PURPOSE

Patients bearing estrogen receptor (ER)α-negative breast cancer tumors confront poor prognosis and are typically unresponsive to hormone therapy. Previous studies have shown that calcitriol, the active vitamin D metabolite, can induce ERα expression in ERα-negative cells. EB1089, a calcitriol analog with reduced calcemic effects, exhibits greater potency than calcitriol in inhibiting cancer cell growth. However, the impact of EB1089 on ERα expression in triple-negative breast cancer (TNBC) cells remains unexplored. This study aims to investigate whether EB1089 could induce functional ERα expression in TNBC cell lines, potentially enabling the antiproliferative effects of antiestrogens.

MATERIALS AND METHODS

TNBC cell lines HCC1806 and HCC1937 were treated with EB1089, and ERα expression was analyzed using real-time PCR and Western blots. The transcriptional activity of induced ERα was evaluated through a luciferase reporter assay. The antiproliferative effects of tamoxifen and fulvestrant antiestrogens were assessed using the sulforhodamine B assay in the EB1089-treated cells.

RESULTS

Our findings indicated that EB1089 significantly induced ERα mRNA and protein expression in TNBC cells. Moreover, EB1089-induced ERα exhibited transcriptional activity and effectively restored the inhibitory effects of antiestrogens, thereby suppressing cell proliferation in TNBC cells.

CONCLUSION

EB1089 induced the expression of functional ERα in TNBC cells, restoring the antiproliferative effects of antiestrogens. These results highlight the potential of using EB1089 as a promising strategy for re-establishment of the antiproliferative effect of antiestrogens as a possible management for TNBC. This research lays the foundation for potential advancements in TNBC treatment, offering new avenues for targeted and effective interventions.

Concise review: breast cancer stems cells and their role in metastases

Background

Breast cancer stem cells (BCSCs) have been suggested to be responsible for the development of Breast cancer (BC). The aim of this study was to evaluate BCSCs and the target organs microenvironment immunophenotyping markers in common BC metastases, and therapeutic targets regarding to the mentioned criteria.

Material and methods

This narrative review involved searching international databases; PubMed, Google Scholar using predetermined keywords including breast cancer, breast cancer stem cells, breast cancer metastases, immunophenotyping, immunohistochemistry and metastases. The search results were assessed based on the title, abstract, and full text of the articles, and relevant findings were included in the review.

Results

BCSCs express high amounts of aldehyde dehydrogenase 1 (ALDH1), Ganglioside 2 (GD2), CD44 and CD133 but are negative for CD24 marker. CXCR4 and OPN have high expression in the cells and may contribute in BC metastasis to the bone. Nestin, CK5, prominin-1 (CD133) markers in BCSCs have been reported to correlate with brain metastasis. High expression of CD44 in BCSCs and CXCL12 expression in the liver microenvironment may contribute to BC metastasis to the liver. Aberrantly expressed vascular cell adhesion molecule-1 (VCAM-1) that binds to collagen and elastin fibers on pulmonary parenchyma, and CXCR4 of BCSCs and CXCL12 in lung microenvironment may promote the cells homing and metastasis to lung.

Conclusion

As in various types of BC metastases different markers that expressed by the cells and target organ microenvironment are responsible, BCSCs immunophenotyping can be used as target markers to predict the disease prognosis and treatment.

Ocular side effects of anticancer agents used in the treatment of gynecologic cancers

The treatment landscape of gynecologic cancers has expanded in recent years to include targeted and immune-based therapies. These therapies often have ocular side effects not seen with conventional chemotherapies, some of which can cause significant visual impairment if not recognized in a timely fashion. Clinicians must know how to appropriately identify, mitigate, and treat these ocular adverse events. Management often involves working with an interdisciplinary team of eye specialists, and it is important to know when to refer patients for specialized care. Proactive identification of eye specialists, especially in rural and community settings where access to care can be limited, may be necessary. Here, we discuss the management of common ocular toxicities seen with novel anticancer agents used to treat gynecologic cancers.

Insights and implications of sexual dimorphism in osteoporosis

Osteoporosis, a metabolic bone disease characterized by low bone mineral density and deterioration of bone microarchitecture, has led to a high risk of fatal osteoporotic fractures worldwide. Accumulating evidence has revealed that sexual dimorphism is a notable feature of osteoporosis, with sex-specific differences in epidemiology and pathogenesis. Specifically, females are more susceptible than males to osteoporosis, while males are more prone to disability or death from the disease. To date, sex chromosome abnormalities and steroid hormones have been proven to contribute greatly to sexual dimorphism in osteoporosis by regulating the functions of bone cells. Understanding the sex-specific differences in osteoporosis and its related complications is essential for improving treatment strategies tailored to women and men. This literature review focuses on the mechanisms underlying sexual dimorphism in osteoporosis, mainly in a population of aging patients, chronic glucocorticoid administration, and diabetes. Moreover, we highlight the implications of sexual dimorphism for developing therapeutics and preventive strategies and screening approaches tailored to women and men. Additionally, the challenges in translating bench research to bedside treatments and future directions to overcome these obstacles will be discussed.

Early Pharmacologic Approaches to Avert Anabolic Steroid-induced Male Infertility: A Narrative Review

PURPOSE

To review the impact of testosterone and other androgenic-anabolic steroids (AASs) on male fertility, exploring potential drugs that can be used to preserve or restore male fertility upon AAS use or prior contact.

METHODS

A review was performed to provide a unifying clinical link between drugs used to preserve or restore male fertility (ie, clomiphene citrate, human chorionic gonadotropin, selective estrogen receptor modulators, recombinant luteinizing and follicle-stimulating hormones, and human menopausal gonadotrophin) in the context of AAS-induced infertility and related aspects.

FINDINGS

Human chorionic gonadotropin (125-500 IU every other day), clomiphene citrate (12.5-50 mg/d), recombinant luteinizing hormone (125-500 IU every other day), recombinant follicle-stimulating hormone (75-150 IU 1-3×/wk), and human menopausal gonadotrophin (75-150 IU 1-3×/wk) are promising early pharmacologic approaches to avert AAS-induced male infertility. Additionally, a full partner assessment is crucial to the success of a couple planning to have children. The partner's age and gynecopathies must be considered. Egg or sperm cryopreservation can also be alternatives for future fertility. Reinforcing AAS cessation is imperative to achieving better success in misusers.

IMPLICATIONS

The exponential increase in AAS misuse raises concerns about the impact on male fertility. This review suggests that gonadotropin analogs and selective androgen receptor modulators (clomiphene citrate) are viable approaches to early preserve or restore fertility in men on AAS use or with previous contact. However, proper standardization of doses and combinations is required and hence physicians should also be aware of patients' and partners' fertility.

Zebrafish as an emerging model to study estrogen receptors in neural development

Estrogens induce several regulatory signals in the nervous system that are mainly mediated through estrogen receptors (ERs). ERs are largely expressed in the nervous system, yet the importance of ERs to neural development has only been elucidated over the last decades. Accumulating evidence shows a fundamental role for estrogens in the development of the central and peripheral nervous systems, hence, the contribution of ERs to neural function is now a growing area of research. The conservation of the structure of the ERs and their response to estrogens make the zebrafish an interesting model to dissect the role of estrogens in the nervous system. In this review, we highlight major findings of ER signaling in embryonic zebrafish neural development and compare the similarities and differences to research in rodents. We also discuss how the recent generation of zebrafish ER mutants, coupled with the availability of several transgenic reporter lines, its amenability to pharmacological studies and in vivo live imaging, could help us explore ER function in embryonic neural development.

Structure-Activity Relationships of Triphenylethylene Derivatives and Their Evaluation as Anticancer and Antiviral Agents

Tamoxifen (TAM) is a selective estrogen receptor modulator (SERM) that is used in the treatment of breast cancer, yet with the risk of developing uterine cancer. A perfect SERM would act as an estrogen activator on bones, the cardiovascular system, and the central nervous system while providing neutral or estrogen blocking effects on the breast and the uterus. Herein, we report on the design, synthesis, and evaluation of new rigid and flexible TAM analogues. Mainly, a chloro substituent is introduced at the para position of the TAM ring C blocking the CYP2D6 hydroxylation site. Most compounds showed estrogenic activity higher than TAM using the yeast estrogen screen assays, indicating the determinant role of the chloro substituent upon functional activity. Despite being estrogenic, compound 2B showed potent antiproliferative activity in the NCI 60 cell lines with mean GI₅₀ = 3.67 μM, GI₅₀ = 1.05 μM on MCF-7 cell lines, and GI₅₀ = 1.30 μM on MDA-MB-231. The estrogenic activity of compound 2B was further confirmed by stimulating alkaline phosphatase in Ishikawa cells, and it showed no increase in relative uterine wet weight in ovariectomized rats. Compound 2F showed EC₉₀ = 0.31 μg/mL and SI₉₀ = 60 against Ebola virus; this is 200-fold more potent than the positive control favipiravir. This is the first time to report estrogenic triphenylethylenes as anti-EBOV agents. The anti-EBOV activity reported is a function of the substitution pattern of the scaffold rather than the functional activity. Moreover, compound 3D showed excellent PO pharmacokinetic properties in mice. In conclusion, for this class of TAM-like compounds, the blockage of the p-position of ring C is decisive for the functional activity; meanwhile, the triarylethylene substitution pattern is detrimental for the antiviral activity.

Gender-affirming endocrine care for youth with a nonbinary gender identity

Nonbinary individuals, or those who identify outside of the traditional gender binary, are currently present in up to 9% of the general population of youth or up to 55% of gender-diverse youth. Despite the high numbers of nonbinary individuals, this population continues to experience barriers to healthcare due to providers' inability to see beyond the transgender binary and lack of competence in providing nonbinary care. In this narrative review, we discuss using embodiment goals to individualize care of nonbinary individuals, and review hormonal and nonhormonal treatment options for gender affirmation. Hormonal treatments include those often used in binary transgender individuals, such as testosterone, estradiol, and anti-androgens, but with adjustments to dosing or timeline to best meet a nonbinary individual's embodiment goals. Less commonly used medications such as selective estrogen receptor antagonists are also discussed. For nonhormonal options, alterations in gender expression such as chest binding, tucking and packing genitalia, and voice training may be beneficial, as well as gender-affirming surgeries. Many of these treatments lack research specific to nonbinary individuals and especially nonbinary youth, and future research is needed to ensure safety and efficacy of gender-affirming care in this population.

Epigenetic and transcriptome responsiveness to ER modulation by tissue selective estrogen complexes in breast epithelial and breast cancer cells

Selective estrogen receptor modulators (SERMs), including the SERM/SERD bazedoxifene (BZA), are used to treat postmenopausal osteoporosis and may reduce breast cancer (BCa) risk. One of the most persistent unresolved questions regarding menopausal hormone therapy is compromised control of proliferation and phenotype because of short- or long-term administration of mixed-function estrogen receptor (ER) ligands. To gain insight into epigenetic effectors of the transcriptomes of hormone and BZA-treated BCa cells, we evaluated a panel of histone modifications. The impact of short-term hormone treatment and BZA on gene expression and genome-wide epigenetic profiles was examined in ERαneg mammary epithelial cells (MCF10A) and ERα+ luminal breast cancer cells (MCF7). We tested individual components and combinations of 17β-estradiol (E2), estrogen compounds (EC10) and BZA. RNA-seq for gene expression and ChIP-seq for active (H3K4me3, H3K4ac, H3K27ac) and repressive (H3K27me3) histone modifications were performed. Our results show that the combination of BZA with E2 or EC10 reduces estrogen-mediated patterns of histone modifications and gene expression in MCF-7ERα+ cells. In contrast, BZA has minimal effects on these parameters in MCF10A mammary epithelial cells. BZA-induced changes in histone modifications in MCF7 cells are characterized by altered H3K4ac patterns, with changes at distal enhancers of ERα-target genes and at promoters of non-ERα bound proliferation-related genes. Notably, the ERα target gene GREB1 is the most sensitive to BZA treatment. Our findings provide direct mechanistic-based evidence that BZA induces epigenetic changes in E2 and EC10 mediated control of ERα regulatory programs to target distinctive proliferation gene pathways that restrain the potential for breast cancer development.

Locally Applied Repositioned Hormones for Oral Bone and Periodontal Tissue Engineering: A Narrative Review

Bone and periodontium are tissues that have a unique capacity to repair from harm. However, replacing or regrowing missing tissues is not always effective, and it becomes more difficult as the defect grows larger. Because of aging and the increased prevalence of debilitating disorders such as diabetes, there is a considerable increase in demand for orthopedic and periodontal surgical operations, and successful techniques for tissue regeneration are still required. Even with significant limitations, such as quantity and the need for a donor area, autogenous bone grafts remain the best solution. Topical administration methods integrate osteoconductive biomaterial and osteoinductive chemicals as hormones as alternative options. This is a promising method for removing the need for autogenous bone transplantation. Furthermore, despite enormous investigation, there is currently no single approach that can reproduce all the physiologic activities of autogenous bone transplants. The localized bioengineering technique uses biomaterials to administer different hormones to capitalize on the host’s regeneration capacity and capability, as well as resemble intrinsic therapy. The current study adds to the comprehension of the principle of hormone redirection and its local administration in both bone and periodontal tissue engineering.

Synthesis, Structural Characterization, and Cytotoxic Activity of New Benzo[d]imidazo[2,1-b]thiazole Derivatives Against MCF-7 Breast Cancer Cells

Breast cancer is an invasive disease with a high prevalence among females. Despite various treatments, studies are still ongoing to find an effective treatment for this disease. This study aimed to synthesize a new series of diaryl benzo[d]imidazo[2,1-b]thiazole compounds containing aminoethoxy side chain and in vitro investigate their cytotoxicity on a human breast cancer cell line (MCF-7). Twelve derivatives (6a-6l) were synthesized from this scaffold, the structures of which were spectroscopically confirmed. The cytotoxic effects of the derivatives on the MCF-7 cell line were also assessed using the MTT assay. All these compounds showed a good inhibitory effect on the MCF-7 cell line, compared to that of tamoxifen. Compounds (6i) and (6j) showed higher cytotoxicity with relevant inhibitory effects of 81% and 73%, respectively.

Selective Estrogen Receptor Modulators (SERMs) Synergize with Cisplatin, Induce Apoptosis and Suppress Cellular Migration and Colony Formation of Lung Cancer Cells

Background:

Lung cancer remains the leading cause of cancer-related deaths worldwide. Hence, novel therapeutic approaches targeting crucial pathways are needed to improve its treatment. Previous studies have verified the involvement of the estrogen pathway, mediated through estrogen receptor β (ERβ), in the development and progression of lung carcinogenesis. Selective estrogen receptor modulators (SERMs) are a group of estrogen receptor agonists/antagonists that have tissue selective effects. Many of the available SERMs are used for the management of breast cancer. However, their role in lung cancer is still under investigation.

Objectives:

The aim of this research is to investigate the anti-tumorigenic activity of the selective estrogen receptor modulators, tamoxifen, raloxifene, and toremifene, against different lung cancer cell lines.

Methods:

The anti-proliferative and combined effects of SERMs with standard chemotherapy were evaluated by MTT assay. Cell migration was assessed using a wound-healing assay. The mechanism of cell death was determined using the Annexin V-FITC/ propidium iodide staining flow cytometry method. Cells’ capability to form colonies was evaluated by soft agar colony formation assay. Estrogen receptors expression was determined using real-time PCR.

Results:

Our results have demonstrated the presence of ERβ in A549, H1299, and H661 lung cancer cells. Cellular proliferation assay suggested that SERMs have significantly reduced lung cancer cells proliferation in a time and concentration- dependent manner. Additionally, SERMs exhibited a synergistic effect against A549 cells when combined with cisplatin. SERMs treatment have increased cell apoptosis and resulted in concentration-dependent inhibition of cell migration and colony formation of A549 cells.

Conclusion:

Selective estrogen receptor modulators may possess potential therapeutic utility for the treatment of lung cancer as monotherapy or in combination with standard chemotherapy.

Risk of venous thromboembolism among women receiving ospemifene: a comparative observational study

Introduction:

The primary aim of this study was to compare the incidence of venous thromboembolism (VTE) among women initiating ospemifene vs other selective estrogen receptor modulator (SERM) therapies for estrogen-deficiency conditions or breast cancer prevention, and vs women with untreated vulvar and vaginal atrophy (VVA). The secondary objective examined numerous additional safety outcomes.

Methods:

This was a retrospective cohort study using the IBM Watson MarketScan claims database. Women receiving ospemifene, another SERM, or with a new diagnosis of VVA with no treatment from 1 May 2013 to 2 October 2018 were followed through the claims for incident adverse outcomes. The primary outcome was the first occurrence of VTE following cohort entry; secondary outcomes included cerebrovascular events and other adverse events potentially associated with SERM use. Cox models compared the risk of VTE between ospemifene and comparators, using a variety of approaches to control for confounding.

Results:

The incidence of VTE during the first continuous treatment episode was 3.39 (95% confidence interval [CI]: 1.55–6.43) events per 1,000 person-years (PY) for ospemifene ( N = 8977), 11.30 (95% CI: 8.81–14.28) events per 1,000 PY for comparator SERM ( N = 12,621), and 10.92 (95% CI: 10.49–11.37) events per 1,000 PY for untreated VVA ( N = 242,488). Cox models indicated no increase in risk of VTE for ospemifene vs other SERMs (hazard ratio [HR]: 0.40, 95% CI: 0.19–0.82), and vs untreated VVA (HR: 0.47, 95% CI: 0.24–0.91).

Conclusion:

This real-world safety analysis found no increase in risk of VTE or other adverse events with use of ospemifene in postmenopausal women.

Plain Language Summary

Introduction: This study assessed the risk of venous thromboembolism (VTE) among women treated with ospemifene or another selective estrogen receptor modulator (SERM) therapy and women with untreated vulvar and vaginal atrophy (VVA). Numerous additional safety outcomes were examined. Methods: This study was conducted in the IBM Watson MarketScan claims database. Women receiving ospemifene, another SERM, or with a new diagnosis of VVA with no treatment from 1 May 2013 to 2 October 2018 were followed through the claims for adverse outcomes, including VTE, cerebrovascular events (such as stroke), and other outcomes that might occur with use of a SERM. The analyses compared the risk of VTE between ospemifene and the other two groups, using methods that accounted for differences in patient characteristics between the groups. Because few women over 72 years old used ospemifene, the main analyses examined women aged 54–72 years. Results: The analyses included 8,977 ospemifene users, 12,621 other SERM users, and 242,488 women with untreated VVA. Among women aged 54–72 years, only 9 experienced a VTE during ospemifene treatment, while 55 other SERM users and 1,788 women with untreated VVA had a VTE. The analyses that accounted for differences between the groups confirmed that the risk of VTE was no higher in ospemifene users than in either comparison group. Conclusion: This real-world safety analysis found no increase in risk of VTE or other adverse events with use of ospemifene in postmenopausal women.

Evaluation of Estrogen Receptor Agonistic Activity of Medicinal Herbs Using Organization for Economic Cooperation and Development Transactivation Assay with Rat Liver S9 Fraction

A number of studies employing different in vitro assays have demonstrated the estrogen-like activity of natural substances. All assays have their advantages and limitations as a screening tool. No single in vitro assay is considered ideal for predicting estrogenic action in a complex in vivo system. To assess agonistic activities of several medicinal herbs on the estrogen receptor (ER) and their metabolic alteration, the Organization for Economic Cooperation and Development (OECD) Performance-Based Test Guideline No. 455 in vitro assay was performed in this study using recombinant VM7Luc4E2 cells in combination with rat liver S9 fractions. Ethanol extracts of medicinal herbs showed binding affinities for ER-α and ER-β at different levels. However, luciferase reporter assay using VM7Luc4E2 cells revealed that only two test extracts [Pueraria lobata root extract (PLE); Glycyrrhiza glabra root extract (GGE)] exhibited ER transcriptional activity when their activities were compared with the response by 17β-estradiol. Importantly, incubation of PLE or GGE with rat liver S9 fractions increased their ER transcriptional activities, in particular when phase I metabolic enzymes were activated. Puerarin and glabridin were the most abundant isoflavones found in PLE and GGE, respectively. The present results demonstrate that PLE and GGE possess potential as ER agonists with their metabolic activation. This study also suggests that the application of OECD in vitro assay with rat liver S9 fraction is an efficient screening tool to evaluate estrogenic activities of natural substances.

Breast cancer risk reduction: who, why, and what?

Women at increased risk of breast cancer have options to mitigate that risk. Understanding factors that increase risk and utilizing tools for quantitative estimates are important to be able to adequately counsel and target strategies for patients. On the basis of these estimates, patients may be able to engage in risk reduction interventions and increased screening, including chemoprevention or surgical risk reduction. Multiple organizations have published guidelines supporting risk assessment, genetic assessment, increased screening, and prevention measures for these women.

Combinations of Calcitriol with Anticancer Treatments for Breast Cancer: An Update

Preclinical, clinical, and epidemiological studies indicate that vitamin D3 (VD) deficiency is a risk factor for the development of breast cancer. Underlying mechanisms include the ability of calcitriol to induce cell differentiation, inhibit oncogenes expression, and modify different signaling pathways involved in the control of cell proliferation. In addition, calcitriol combined with different kinds of antineoplastic drugs has been demonstrated to enhance their beneficial effects in an additive or synergistic fashion. However, a recognized adjuvant regimen based on calcitriol for treating patients with breast cancer has not yet been fully established. Accordingly, in the present work, we review and discuss the preclinical and clinical studies about the combination of calcitriol with different oncological drugs, aiming to emphasize its main therapeutic benefits and opportunities for the treatment of this pathology.

The role of TRPV channels in osteoporosis

As the world's population ages, the treatment of osteoporosis is a major problem to be addressed. The cause of osteoporosis remains unclear. Ca²⁺ is not only an important component of bones but also plays a key role in osteoporosis treatment. Transient receptor potential vanilloid (TRPV) channels are one of the TRP channel families that is widely distributed in various organs, playing an important role in the physiological regulation of the human body. Bone formation and bone absorption may require Ca²⁺ transport via TRPV channels. It has been proven that the TRPV subtypes 1, 2, 4, 5, 6 (TRPV1, TRPV2, TRPV4, TRPV5, TRPV6) may affect bone metabolism balance through selective regulation of Ca²⁺. They significantly regulate osteoblast/osteoclast proliferation, differentiation and function. The purpose of this review is to explore the mechanisms of TRPV channels involved in regulation of the differentiation of osteoblasts and osteoclasts, as well as to discuss the latest developments in current researches, which may provide new clues and directions for an in-depth study of osteoporosis and other related bone metabolic diseases.

Incident Type 2 Diabetes Risk of Selective Estrogen Receptor Modulators in Female Patients with Breast Cancer

Accumulating evidence indicates a link between diabetes and cancer. Selective estrogen receptor modulators (SERMs) may increase diabetes risk via antiestrogen effects. This study investigated incident diabetes risk of SERM treatment and its effects on metastatic cancer and death prevention in breast cancer survivors. This retrospective cohort study included female patients with early-stage breast cancer, treated with or without SERMs, between 2008 and 2020 in a tertiary care hospital in Korea. Four propensity score-matched comparison pairs were designed: SERM use versus non-use, long-term use (≥1500 days) versus non-use, tamoxifen use versus non-use, and toremifene use versus non-use; then, logistic regression analysis was performed for risk analysis. SERMs in general were not associated with an elevated risk of diabetes; however, when used for ≥1500 days, SERMs—especially toremifene—substantially increased diabetes risk in breast cancer patients (OR 1.63, p = 0.048). Meanwhile, long-term SERM treatment was effective at preventing metastatic cancer (OR 0.20, p < 0.001) and death (OR 0.13, p < 0.001). SERM treatment, albeit generally safe and effective, may increase diabetes risk with its long-term use in women with breast cancer. Further studies are required to verify the association between toremifene treatment and incident diabetes.

Incidence and Risk of Venous Thromboembolism in Bisphosphonates and Selective Estrogen Receptor Modulators Treatment in Korea

BACKGROUND

Selective estrogen receptor modulators (SERMs) were associated with an increased risk of venous thromboembolism (VTE) due to the estrogen effect. In this study, we investigated the effect of SERMs on VTE compared to bisphosphonates (BPs) using the Korean National Health Insurance claims database.

METHODS

This was a retrospective cohort study. Women over 50 years old who were first prescribed BPs or SERMs for osteoporosis treatment in 2012 were included. The difference in VTE incidence between the SERMs and BP groups was compared. Both groups were followed up for VTE or PE occurrence, death, or until December 2016. The study population was analyzed by 3:1 matching according to age using a multivariate Cox model.

RESULTS

The hazard ratio (HR) for VTE was 0.72 (95% confidence interval [CI], 0.40-1.28) in the SERMs group compared to BP group. Older age (60-69 vs. 50-59 years: HR, 3.77; 95% CI, 2.07-6.86 and 70-79 vs. 50-59 years: HR, 5.88; 95% CI, 3.14-11.02), major osteoporotic fracture (HR, 1.77; 95% CI, 1.16- 2.70), atrial fibrillation (HR, 3.31; 95% CI, 1.35-8.11), and estrogen replacement (HR, 3.40; 95% CI, 2.01-5.73) all increased VTE risk. In subgroup analysis of the SERMs group, past hospitalization (HR, 2.24; 95% CI, 1.02-4.92), estrogen replacement (HR, 5.75; 95% CI, 2.29-14.39), and glucocorticoid replacement (HR, 2.71; 95% CI, 1.05-7.0) increased VTE risk.

CONCLUSION

SERMs did not increase the risk of VTE compared to BPs in Koreans with osteoporosis. However, old age and estrogen replacement both increased VTE risk.

Formulation and evaluation of raloxifene hydrochloride dry emulsion tablet using solid carrier adsorption technique

Aim: The present study focused on the development of a dry emulsion tablet of raloxifene hydrochloride (RXF) using a solid carrier adsorption technique to enhance oral bioavailability. Methods: An oil-in-water emulsion was formulated and converted into dry powder using HPMC K4M plus Aerosil 200, then compressed into tablets. Results: The prepared emulsion was evaluated for globule size, drug content and zeta potential. In vitro release study revealed significantly higher release from emulsion. The prepared tablets possessed acceptable hardness, friability, weight variation, disintegration time, thickness, etc. In vivo pharmacokinetic studies indicated a more than sevenfold increase in oral bioavailability. Stability studies indicated good physical and chemical stability of the developed formulation. Conclusion: The authors successfully formulated dry emulsion tablets with enhanced oral bioavailability.

Estrogen deficiency - a central paradigm in age-related impaired healing?

Wound healing is a dynamic biological process achieved through four sequential, overlapping phases; hemostasis, inflammation, tissue proliferation and remodeling. For effective wound healing, all four phases must occur in the appropriate order and time frame. It is well accepted that the wound healing process becomes disrupted in the elderly, increasing the propensity of non-healing wound states that can lead to substantial patient morbidity and an enormous financial burden on healthcare systems. Estrogen deprivation in the elderly has been identified as the key driver of age-related delayed wound healing in both genders, with topical and systemic estrogen replacement reversing the detrimental effects of aging on wound repair. Evidence suggests estrogen deprivation may contribute to the development of chronic wound healing states in the elderly but research in this area is somewhat limited, warranting further investigations. Moreover, although the beneficial effects of estrogen on cutaneous healing have been widely explored, the development of estrogen-based treatments to enhance wound repair in the elderly have yet to be widely exploited. This review explores the critical role of estrogen in reversing age-related impaired healing and evaluates the prospect of developing more focused novel therapeutic strategies that enhance wound repair in the elderly via activation of specific estrogen signaling pathways in regenerating tissues, whilst leaving non-target tissues largely unaffected.

Selective Estrogen Receptor Modulators: A Potential Option For Non-Binary Gender-Affirming Hormonal Care?

Gender dysphoria describes the distress associated with having a gender identity that differs from one's birth-assigned sex. To relieve this distress, transgender, and gender diverse (henceforth, trans) individuals commonly undergo medical transition involving hormonal treatments. Current hormonal treatment guidelines cater almost exclusively for those who wish to transition from male to female or vice versa. In contrast, there is a dearth of hormonal options for those trans individuals who identify as non-binary and seek an androgynous appearance that is neither overtly male nor female. Though prolonged puberty suppression with gonadotrophin releasing hormone agonists (GnRHa) could in theory be gender-affirming by preventing the development of unwanted secondary sex characteristics, this treatment option would be limited to pre- or peri-pubertal adolescents and likely have harmful effects. Here, we discuss the theoretical use of Selective Estrogen Receptor Modulators (SERMs) for non-binary people assigned male at birth (AMAB) who are seeking an androgynous appearance through partial feminization without breast growth. Given their unique range of pharmacodynamic effects, SERMs may represent a potential gender-affirming treatment for this population, but there is a lack of knowledge regarding their use and potentially adverse effects in this context.

Elastography of Endometrium in Women Taking Tamoxifen: A New Approach to an Old Diagnostic Problem

Tamoxifen is a commonly used selective estrogen receptor modulator applied in the treatment for breast cancer. However, in the endometrium, Tamoxifen stimulates tissue growth, cellular transformation, the migration of the cells, and metastatic potential in endometrial cancer. Considering that uterine cancer is the most common neoplasm of the reproductive tract and the third most common neoplastic disease in women, the aim of this study was to investigate if applying elastography in examining the endometrium was beneficial for uterine cancer screening protocols in women on selective estrogen receptor modulator therapy. This study was based on the execution of a classic assessment of the endometrium that included the evaluation of the following: echogenicity, central endometrial stripe, presence of fluid in the uterine lumen, myometrium–endometrium interface, intensity of vascularization and vascular pattern. An ultrasound presentation was then processed and analyzed with elastography. The values of the elastography parameters demonstrated good consistency for the measurement of the softest endometrial layer thickness in elastography. A strong positive correlation (R = 0.56) was demonstrated between the endometrial thickness, as determined by ultrasound examination, and the softest endometrial layer in elastography (p < 0.001). The research showed that the elastography measurements of the width of the softest endometrium layer, based on a population of women taking Tamoxifen, appeared to be a promising option for endometrial cancer screening.

G Protein-Coupled Estrogen Receptor 1 Knockout Deteriorates MK-801-Induced Learning and Memory Impairment in Mice

The role of estrogen receptors in neuroprotection and cognition has been extensively studied in humans over the past 20 years. Recently, studies have shifted their focus to the use of selective estrogen receptor modulators in the treatment of mental illnesses in the central nervous system. We conducted this study to test the behavioral changes shown by G protein-coupled estrogen receptor 1 knockout (GPER1 KO) and wild-type (WT) mice with MK-801-induced schizophrenia (SZ). GPER1 KO and WT mice received intraperitoneal injections of MK-801 for 14 continuous days. Behavioral, learning and memory, and social interaction changes were evaluated by using the IntelliCage system, open-field, three-chamber social interaction, and novel object recognition tests (NORT). The protein expression levels of the NR2B/CaMKII/CREB signaling pathway were tested via Western blot analysis. The KO SZ group was more likely to show impaired long-term learning and memory function than the WT SZ group. Learning and memory functions were also impaired in the KO Con group. MK-801 administration to the GPER1-KO and WT groups resulted in memory deficiencies and declining learning capabilities. GPER1 deficiency downregulated the expression levels of proteins related to the NR2B/CaMKII/CREB signaling pathway. Our study suggested that GPER1 played an important role in cognitive, learning, and memory functions in the MK-801-induced mouse model of SZ. The mechanism of this role might partially involve the downregulation of the proteins related to the NR2B/CaMKII/CREB signaling pathway. Further studies should focus on the effect of GPER1 on the pathogenesis of SZ in vivo and in vitro.

Challenges and Opportunities in Cancer Drug Resistance

There has been huge progress in the discovery of targeted cancer therapies in recent years. However, even for the most successful and impactful cancer drugs which have been approved, both innate and acquired mechanisms of resistance are commonplace. These emerging mechanisms of resistance have been studied intensively, which has enabled drug discovery scientists to learn how it may be possible to overcome such resistance in subsequent generations of treatments. In some cases, novel drug candidates have been able to supersede previously approved agents; in other cases they have been used sequentially or in combinations with existing treatments. This review summarizes the current field in terms of the challenges and opportunities that cancer resistance presents to drug discovery scientists, with a focus on small molecule therapeutics. As part of this review, common themes and approaches have been identified which have been utilized to successfully target emerging mechanisms of resistance. This includes the increase in target potency and selectivity, alternative chemical scaffolds, change of mechanism of action (covalents, PROTACs), increases in blood-brain barrier permeability (BBBP), and the targeting of allosteric pockets. Finally, wider approaches are covered such as monoclonal antibodies (mAbs), bispecific antibodies, antibody drug conjugates (ADCs), and combination therapies.

Recent progress in selective estrogen receptor downregulators (SERDs) for the treatment of breast cancer

Selective estrogen receptor downregulators (SERDs) are a novel class of compounds capable of reducing the ERα protein level and blocking ER activity. Therefore, SERDs are considered as a significant therapeutic approach to treat ER+ breast cancer in both early stage and more advanced drug-resistant cases. After the FDA approval of a steroidal drug, fulvestrant, as a SERD for the treatment of breast cancer in patients who have progressed on antihormonal agents, several molecules with diverse chemical structures have been rapidly developed, studied and evaluated for selective estrogen receptor downregulation activity. Here we compile the promising SERDs reported in recent years and discuss the chemical structure and pharmacological profile of the most potent compound of the considered series. Because of the availability of only a limited number of effective drugs for the treatment of breast cancer, the quest for a potent SERD with respectable activity and bioavailability is still ongoing. The goal of this article is to make available to the reader an overview of the current progress in SERDs and provide clues for the future discovery and development of novel pharmacological potent SERDs for the treatment of breast cancer.

Design, synthesis, and biological activity of a novel series of benzofuran derivatives against oestrogen receptor-dependent breast cancer cell lines

A docking study of a novel series of benzofuran derivatives with ERα was conducted. In this study, we report the synthesis of a novel series of benzofuran derivatives and evaluation of their anticancer activity in vitro against MCF-7 human breast cancer cells, as well as their potential toxicity to ER-independent MDA-MB-231 breast cancer cells, human renal epithelial HEK-293 cells, and human immortal keratinocytes (HaCaT cells) by using the MTT colorimetric assay. The screening results indicated that the target compounds exhibited anti-breast cancer activity. The target compound 2-benzoyl-3-methyl-6-[2-(morpholin-4-yl)ethoxy]benzofuran hydrochloride (4e) exhibited excellent activity against anti-oestrogen receptor-dependent breast cancer cells and low toxicity. The preliminary structure-activity relationships of the target benzofuran derivatives have been summarised. In conclusion, the novel benzofuran scaffold may be a promising lead for the development of potential oestrogen receptor inhibitors.

Risk-reducing medications for primary breast cancer: a network meta-analysis

BACKGROUND

Breast cancer is the most frequently occurring malignancy and the second cause of death for cancer in women. Cancer prevention agents (CPAs) are a promising approach to reduce the burden of breast cancer. Currently, two main types of CPAs are available: selective estrogen receptor modulators (SERMs, such as tamoxifen and raloxifene) and aromatase inhibitors (AIs, such as exemestane and anastrozole).

OBJECTIVES

To assess the efficacy and acceptability of single CPAs for the prevention of primary breast cancer, in unaffected women, at an above-average risk of developing breast cancer.Using a network meta-analysis, to rank single CPAs, based on their efficacy and acceptability (an endpoint that is defined as the inverse of CPA-related toxicity).

SEARCH METHODS

We searched the Cochrane Breast Cancer Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, World Health Organization's International Clinical Trials Registry Platform (WHO ICTRP), and ClinicalTrials.gov on 17 August 2018. We handsearched reference lists to identify additional relevant studies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that enrolled women without a personal history of breast cancer but with an above-average risk of developing a tumor. Women had to be treated with a CPA and followed up to record the occurrence of breast cancer and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and conducted risk of bias assessments of the included studies, and assessed the certainty of the evidence using GRADE. Outcome data included incidence of breast carcinoma (both invasive and in situ carcinoma) and adverse events (both overall and severe toxicity). We performed a conventional meta-analysis (for direct comparisons of a single CPA with placebo or a different CPA) and network meta-analysis (for indirect comparisons).

MAIN RESULTS

We included six studies enrolling 50,927 women randomized to receive one CPA (SERMs: tamoxifen or raloxifene, or AIs: exemestane or anastrozole) or placebo. Three studies compared tamoxifen and placebo, two studies compared AIs (exemestane or anastrozole) versus placebo, and one study compared tamoxifen versus raloxifene. The risk of bias was low for all RCTs.For the tamoxifen versus placebo comparison, tamoxifen likely resulted in a lower risk of developing breast cancer compared to placebo (risk ratio (RR) 0.68, 95% confidence interval (CI) 0.62 to 0.76; 3 studies, 22,832 women; moderate-certainty evidence). In terms of adverse events, tamoxifen likely increased the risk of severe toxicity compared to placebo (RR 1.28, 95% CI 1.12 to 1.47; 2 studies, 20,361 women; moderate-certainty evidence). In particular, women randomized to receive tamoxifen experienced a higher incidence of both endometrial carcinoma (RR 2.26, 95% CI 1.52 to 3.38; high-certainty evidence) and thromboembolism (RR 2.10, 95% CI 1.14 to 3.89; high-certainty evidence) compared to women who received placebo.For the AIs versus placebo comparison, AIs (exemestane or anastrozole) reduced the risk of breast cancer by 53% (RR 0.47, 95% CI 0.35 to 0.63; 2 studies, 8424 women; high-certainty evidence). In terms of adverse events, AIs increased the risk of severe toxicity by 18% (RR 1.18, 95% CI 1.09 to 1.28; 2 studies, 8352 women; high-certainty evidence). These differences were sustained especially by endocrine (e.g. hot flashes), gastrointestinal (e.g. diarrhea), and musculoskeletal (e.g. arthralgia) adverse events, while there were no differences in endometrial cancer or thromboembolism rates between AIs and placebo.For the tamoxifen versus raloxifene comparison, raloxifene probably performed worse than tamoxifen in terms of breast cancer incidence reduction (RR 1.25, 95% CI 1.09 to 1.43; 1 study, 19,490 women; moderate-certainty evidence), but its use was associated with lower toxicity rates (RR 0.87, 95% CI 0.80 to 0.95; 1 study, 19,490 women; moderate-certainty evidence), particularly relating to incidence of endometrial cancer and thromboembolism.An indirect comparison of treatment effects allowed us to compare the SERMs and AIs in this review. In terms of efficacy, AIs (exemestane or anastrozole) may have reduced breast cancer incidence slightly compared to tamoxifen (RR 0.67, 95% CI 0.46 to 0.98; 5 RCTs, 31,256 women); however, the certainty of evidence was low. A lack of model convergence did not allow us to analyze toxicity data.

AUTHORS' CONCLUSIONS

For women with an above-average risk of developing breast cancer, CPAs can reduce the incidence of this disease. AIs appear to be more effective than SERMs (tamoxifen) in reducing the risk of developing breast cancer. AIs are not associated with an increased risk of endometrial cancer and thromboembolic events. However, long-term data on toxicities from tamoxifen are available while the follow-up toxicity data on unaffected women taking AIs is relatively short. Additional data from direct comparisons are needed to fully address the issues of breast cancer prevention by risk-reducing medications, with special regards to acceptability (i.e. the benefit/harm ratio).

Updating the role of obesity and cholesterol in breast cancer

BACKGROUND

Breast cancer is the second most common cause of cancer-related death among women. Advances in our understanding of the disease have translated into better diagnostics and more effective therapeutics, leading to earlier detection and improved outcomes. Several studies have pointed at lifestyle and environmental factors as contributory for the onset and progression of the disease. Obesity and cholesterol stand out for their potential causal relationship with breast cancer and ease of modification.

MAIN TEXT

Obesity and cholesterol represent risk factors for breast cancer, but their impact is largely affected by cofounding variables including menopausal status, disease subtype, and inflammation. Establishing a causal relationship between lifestyle factors and clinical outcomes may be challenging. Epidemiological studies and meta-analyses have rendered conflicting or sometimes contradictory results, possibly owing to the multifactorial nature of the disease. We discuss the supporting evidence and limitations in our understanding of obesity and cholesterol as risk factors for breast cancer.

CONCLUSIONS

There is sufficient evidence that obesity and cholesterol impact clinical outcomes. Physicians are advised to take steps to help patients with their weight, such as recommending dietary and lifestyle interventions.

Astrocytes Mediate Protective Actions of Estrogenic Compounds after Traumatic Brain Injury

Traumatic brain injury (TBI) is a serious public health problem. It may result in severe neurological disabilities and in a variety of cellular metabolic alterations for which available therapeutic strategies are limited. In the last decade, the use of estrogenic compounds, which activate protective mechanisms in astrocytes, has been explored as a potential experimental therapeutic approach. Previous works have suggested estradiol (E2) as a neuroprotective hormone that acts in the brain by binding to estrogen receptors (ERs). Several steroidal and nonsteroidal estrogenic compounds can imitate the effects of estradiol on ERs. These include hormonal estrogens, phytoestrogens and synthetic estrogens, such as selective ER modulators or tibolone. Current evidence of the role of astrocytes in mediating protective actions of estrogenic compounds after TBI is reviewed in this paper. We conclude that the use of estrogenic compounds to modulate astrocytic properties is a promising therapeutic approach for the treatment of TBI.

Knockdown of DNA/RNA-binding protein KIN17 promotes apoptosis of triple-negative breast cancer cells

Effective therapy for breast cancer has been extensively studied worldwide, particularly for triple-negative breast cancer and drug-resistant subtypes. DNA/RNA-binding protein KIN17 (kin17) has been reported to be significantly upregulated in breast cancer cells, and is proposed to serve a role in the regulation of cell proliferation. The present study further investigated the association of kin17-knockdown with breast cancer cell apoptosis. Cell Counting kit-8, flow cytometry, TUNEL assay and caspase 3/7 analysis were performed on MDA-MB-231 cells to determine the association between kin17 and breast cancer cell apoptosis. In addition, western blot analysis was performed to investigate the mechanism of kin17 in the apoptosis of MDA-MB-231 cells. The results revealed that knockdown of kin17 inhibited proliferation and promoted apoptosis of MDA-MB-231 cells, and suggested a poly (adenosine diphosphate-ribose) polymerase-related mechanism behind the apoptosis of the cells. These findings suggested that kin17 could become a novel target for breast cancer therapy.

Breast cancer stem cells: Biology and therapeutic implications

Breast cancer remains to be a dreadful disease even with several advancements in radiation and chemotherapies, owing to the drug resistance and tumor relapse caused by breast cancer stem cells. Cancer stem cells are a minute population of cells of solid tumors which show self-renewal and differentiation properties as well as tumorigenic potential. Several signaling pathways including Notch, Hippo, Wnt and Hedgehog and tumor-stroma exchanges play a critical role in the self-renewal and differentiation of cancer stem cells in breast cancer. Cancer stem cells can grow anchorage-independent manner so they disseminate to different parts of the body to form secondary tumors. Cancer stem cells promote angiogenesis by dedifferentiating to endothelial cells as well as secreting proangiogenic and angiogenic factors. Moreover, multidrug resistance genes and drug efflux transporters expressed in breast cancer stem cells confer resistance to various conventional chemotherapeutic drugs. Indeed, these therapies are recognised to enhance the percent of cancer stem cell population in tumors leading to cancer relapse with increased aggressiveness. Hence, devising the therapeutic interventions to target cancer stem cells would be useful in increasing patients' survival rates. In addition, targeting the self-renewal pathways and tumor-stromal cross-talk helps in eradicating this population. Reversal of the cancer stem cell-mediated drug resistance would increase the sensitivity to various conventional drugs for the effective management of breast cancer. In this review, we have discussed the cancer stem cell origin and their involvement in angiogenesis, metastasis and therapy-resistance. We have also summarized different therapeutic approaches to eradicate the same for the successful treatment of breast cancer.

Current treatment options for postmenopausal vaginal atrophy

Vulvovaginal atrophy (VVA) is a silent epidemic that affects up to 50%–60% of postmenopausal women who are suffering in silence from this condition. Hormonal changes, especially hypoestrogenism inherent in menopause, are characterized by a variety of symptoms. More than half of menopausal women are concerned about the symptoms of VVA, such as dryness, burning, itching, vaginal discomfort, pain and burning when urinating, dyspareunia, and spotting during intercourse. All these manifestations significantly reduce the quality of life and cause discomfort in the sexual sphere. However, according to research, only 25% of patients with the symptoms of VVA receive adequate therapy. This is probably due to the lack of coverage of this problem in the society and the insufficiently active position of specialists in the field of women’s health regarding the detection of symptoms of VVA. Many patients are embarrassed to discuss intimate complaints with a specialist, which makes it difficult to verify the diagnosis in 75% of cases, and some patients regard the symptoms of VVA as manifestations of the natural aging process and do not seek help. Modern medicine has in the arsenal various options for treating this pathological condition, including systemic and topical hormone replacement therapy, the use of selective estrogen receptor modulators, vaginal dehydroepiandrosterone, use of lubricants and moisturizers, as well as non-drug therapies. Timely diagnosis and adequately selected therapy for the main symptoms of VVA lead to restoration and maintenance of the vaginal function and vaginal health.

Receptor tyrosine kinases (RTKs) in breast cancer: signaling, therapeutic implications and challenges

Breast cancer is a multifactorial disease and driven by aberrant regulation of cell signaling pathways due to the acquisition of genetic and epigenetic changes. An array of growth factors and their receptors is involved in cancer development and metastasis. Receptor Tyrosine Kinases (RTKs) constitute a class of receptors that play important role in cancer progression. RTKs are cell surface receptors with specialized structural and biological features which respond to environmental cues by initiating appropriate signaling cascades in tumor cells. RTKs are known to regulate various downstream signaling pathways such as MAPK, PI3K/Akt and JAK/STAT. These pathways have a pivotal role in the regulation of cancer stemness, angiogenesis and metastasis. These pathways are also imperative for a reciprocal interaction of tumor and stromal cells. Multi-faceted role of RTKs renders them amenable to therapy in breast cancer. However, structural mutations, gene amplification and alternate pathway activation pose challenges to anti-RTK therapy.

Clinical investigation of RAD1901, a novel estrogen receptor ligand, for the treatment of postmenopausal vasomotor symptoms: a phase 2 randomized, placebo-controlled, double-blind, dose-ranging, proof-of-concept trial

OBJECTIVE

The aim of the study was to assess the efficacy and safety of RAD1901, an oral estrogen receptor ligand, for the treatment of moderate-to-severe vasomotor symptoms of menopause.

METHODS

This was a randomized, placebo-controlled, double-blind, dose-ranging, proof-of-concept trial. Postmenopausal women with a minimum of 7 moderate-to-severe, diary-reported hot flashes per day, or 50 per week, were randomized to one of five blinded dose groups (0 [placebo], 10, 25, 50, or 100 mg RAD1901 daily for 28 d). Efficacy endpoints included frequency and severity of hot flashes over 4 weeks of treatment.

RESULTS

One hundred participants were randomized across the five treatment regimens. The frequency of moderate-to-severe hot flashes decreased in all groups over the treatment period (mean percent change from baseline at 4 wk, -54.1%, -77.2%, -51.8%, -53.8%, and -67.0% for placebo, 10, 25, 50, and 100 mg groups). The response in the 10 mg group was significantly different from placebo at 4 weeks (P = 0.024). No other dose group was significantly different from placebo. There were no statistically significant differences in severity of hot flashes between placebo and any dose group. Treatment was well tolerated; most treatment-emergent adverse events were mild to moderate in severity.

CONCLUSIONS

Daily treatment with 10 mg RAD1901 over 4 weeks resulted in a statistically significant reduction in the frequency of moderate-to-severe hot flashes compared with placebo, with an acceptable safety profile. Further clinical trials are warranted to investigate RAD1901's utility as a potential treatment for vasomotor symptoms.

Bazedoxifene and raloxifene protect neocortical neurons undergoing hypoxia via targeting ERα and PPAR-γ

Selective estrogen receptor modulators (SERMs) such as bazedoxifene and raloxifene are recognized to mainly act via estrogen receptors (ERs), but there is no study examining the involvement of PPAR-γ in their actions, especially in neurons undergoing hypoxia. Little is also known about age-dependent actions of the SERMs on neuronal tissue challenged with hypoxia. In this study, bazedoxifene and raloxifene protected neocortical cells against hypoxia at early and later developmental stages. Both SERMs evoked caspase-3-independent neuroprotection and increased protein levels of ERα (66 and 46 kDa isoforms) and PPAR-γ. In addition, bazedoxifene enhanced expression of ERα-regulated Cyp19a1 mRNA. Using double siRNA silencing, for the first time we demonstrated a key role of ERα and PPAR-γ in the neuroprotective action of the SERMs in neocortical neurons undergoing hypoxia. This study provides prospects for the development of a new therapeutic strategies against hypoxic brain injury that selectively target ERα and/or PPAR-γ.

ZNF423: A New Player in Estrogen Receptor-Positive Breast Cancer

Preventive therapy can target hormone-responsive breast cancer (BC) by treatment with selective estrogen receptor modulators (SERMs) and reduce the incidence of BC. Genome-wide association studies have identified single nucleotide polymorphisms (SNPs) with relevant predictive values, SNPs in the ZNF423 gene were associated with decreased risk of BC during SERM therapy, and SNPs in the Cathepsin O gene with an increased risk. ZNF423, which was not previously associated with BC is a multifunctional transcription factor known to have a role in development, neurogenesis, and adipogenesis and is implicated in other types of cancer. ZNF423 is transcriptionally controlled by the homolog ZNF521, early B cell factor transcription factor, epigenetic silencing of the promoter by CpG island hyper-methylation, and also by ZNF423 itself in an auto-regulatory loop. In BC cells, ZNF423 expression is found to be induced by estrogen, dependent on the binding of the estrogen receptor and calmodulin-like 3 to SNPs in ZNP423 intronic sites in proximity to consensus estrogen response elements. ZNF423 has also been shown to play a mechanistic role by trans-activating the tumor suppressor BRCA1 and thus modulating the DNA damage response. Even though recent extensive trial studies did not classify these SNPs with the highest predictive values, for inclusion in polygenic SNP analysis, the mechanism unveiled in these studies has introduced ZNF423 as a factor important in the control of the estrogen response. Here, we aim at providing an overview of ZNF423 expression and functional role in human malignancies, with a specific focus on its implication in hormone-responsive BC.

Estrogenic Potentials of Traditional Chinese Medicine

Estrogen, a steroid hormone, is associated with several human activities, including environmental, industrial, agricultural, pharmaceutical and medical fields. In this review paper, estrogenic activity associated with traditional Chinese medicines (TCMs) is discussed first by focusing on the assays needed to detect estrogenic activity (animal test, cell assay, ligand-binding assay, protein assay, reporter-gene assay, transcription assay and yeast two-hybrid assay), and then, their sources, the nature of activities (estrogenic or anti-estrogenic, or other types), and pathways/functions, along with the assay used to detect the activity, which is followed by a summary of effective chemicals found in or associated with TCM. Applications of estrogens in TCM are then discussed by a comprehensive search of the literature, which include basic study/pathway analysis, cell functions, diseases/symptoms and medicine/supplements. Discrepancies and conflicting cases about estrogenicity of TCM among assays or between TCM and their effective chemicals, are focused on to enlarge estrogenic potentials of TCM by referring to omic knowledge such as transcriptome, proteome, glycome, chemome, cellome, ligandome, interactome and effectome.

Skeletal and Uterotrophic Effects of Endoxifen in Female Rats

Endoxifen, the primary active metabolite of tamoxifen, is currently being investigated as a novel endocrine therapy for the treatment of breast cancer. Tamoxifen is a selective estrogen receptor modulator that elicits potent anti-breast cancer effects. However, long-term use of tamoxifen also induces bone loss in premenopausal women and is associated with an increased risk of endometrial cancer in postmenopausal women. For these reasons, we have used a rat model system to comprehensively characterize the impact of endoxifen on the skeleton and uterus. Our results demonstrate that endoxifen elicits beneficial effects on bone in ovary-intact rats and protects against bone loss following ovariectomy. Endoxifen is also shown to reduce bone turnover in both ovary-intact and ovariectomized rats at the cellular and biochemical levels. With regard to the uterus, endoxifen decreased uterine weight but maintained luminal epithelial cell height in ovariectomized animals. Within luminal epithelial cells, endoxifen resulted in differential effects on the expression levels of estrogen receptors α and β as well as multiple other genes previously implicated in regulating epithelial cell proliferation and hypertrophy. These studies analyze the impact of extended endoxifen exposure on both bone and uterus using a Food and Drug Administration-recommended animal model. Although endoxifen is a more potent breast cancer agent than tamoxifen, the results of the present study demonstrate that endoxifen does not induce bone loss in ovary-intact rats and that it elicits partial agonistic effects on the uterus and skeleton in ovariectomized animals.

Sex and gender differences in HIV-1 infection

The major burden of the human immunodeficiency (HIV) type 1 pandemic is nowadays carried by women from sub-Saharan Africa. Differences in the manifestations of HIV-1 infection between women and men have been long reported, and might be due to both socio-economic (gender) and biological (sex) factors. Several studies have shown that women are more susceptible to HIV-1 acquisition than men. Following HIV-1 infection, women have lower viral loads during acute infection and exhibit stronger antiviral responses than men, which may contribute to differences in the size of viral reservoirs. Oestrogen receptor signalling could represent an important mediator of sex differences in HIV-1 reservoir size and may represent a potential therapeutic target. Furthermore, immune activation, a hallmark of HIV-1 infection, is generally higher in women than in men and could be a central mechanism in the sex difference observed in the speed of HIV-1 disease progression. Here, we review the literature regarding sex-based differences in HIV-1 infection and discuss how a better understanding of the underlying mechanisms could improve preventive and therapeutic strategies.

Estrogen receptor agonists/antagonists in breast cancer therapy: A critical review

Estrogens display intriguing tissue selective action that is of great biomedical importance in the development of optimal therapeutics for the prevention and treatment of breast cancer. There are also strong evidences to show that both endogenous and exogenous estrogens are involved in the pathogenesis of breast cancer. Tamoxifen has been the only drug of choice for more than 30years to treat patients with estrogen related (ER) positive breast tumors. There is a need therefore, for identifying newer, potential and novel candidates for breast cancer. Keeping this in view, the present review focuses on selective estrogen receptor modulators and estrogen antagonists such as sulfatase and aromatase inhibitors involved in breast cancer therapy. A succinct and critical overview of the structure of estrogen receptors, their signaling and involvement in breast carcinogenesis are herein described.

Menopause as a potential cause for higher prevalence of low back pain in women than in age-matched men

Female sex hormones play an important role in the aetiology and pathophysiology of a variety of musculoskeletal degenerative diseases. Postmenopausal women show accelerated disc degeneration due to relative oestrogen deficiency, resulting in narrower intervertebral disc space in women than age-matched men, increased prevalence of spondylolisthesis, and increased prevalence of facet joint osteoarthritis. Postmenopausal women also show higher osteoporosis related spine fracture rate, particularly at the thoracic-lumbar junction site. I propose the concept that low back pain (LBP) is more prevalent in postmenopausal women than age-matched men and is associated with the physiological changes caused by the relatively lower level of sex hormones after menopause in women. Considering hormone replacement treatment (HRT)'s consistent efficacy reported with menopause-associated osteoarthritis, an in-depth understanding of the role of the gonadal hormones in LBP modulation warrants further study. HRT initiated at early postmenopausal phase may be protective for recurring LBP. If this is the case, further cost-benefit analysis should be performed for optimal HRT regimen in cases of women with high risk of recurring severe LBP.

Selenophene and thiophene-core estrogen receptor ligands that inhibit motility and development of parasitic stages of Haemonchus contortus

Background

Parasitic worms represent a substantial disease burden in animals and humans worldwide. The control of parasitic roundworms (nematodes) relies heavily on the use of anthelmintic drugs. However, widespread drug resistance in nematodes seriously compromises the effectiveness of many anthelmintics around the world. Thus, there is a need to discover new drugs, with unique modes of action, against parasites.

Methods

Here, we synthesised and tested 74 selective estrogen receptor modulators (SERMs) for in vitro-activity on parasitic larvae of Haemonchus contortus (barber’s pole worm), one of the most important nematode pathogens of small ruminants (including sheep and goats) and a key representative of one of the largest groups of parasitic nematodes (the Strongylida) of animals. We also studied the morphology of treated and untreated larvae using scanning electron microscopy (SEM), and assessed the agonistic/antagonistic activity of SERMs in a human embryonic kidney cell line using a luciferase reporter assay system.

Results

We identified three SERMs (one selenophene and two thiophene-core compounds) with potent inhibitory activities (at 3–25 μM) on the motility and development of parasitic stages of H. contortus. An SEM examination of treated H. contortus revealed considerable damage to the cuticle of fourth- but not exsheathed, third-stage larvae; this damage appeared to be consistent with that observed upon treatment with monepantel but not moxidectin (control compounds).

Conclusion

The potency of the three SERMs compared favourably with commercially available anthelmintics, such that they warrant further assessment as nematocides. Future studies could focus on assessing the selectivity of these SERMs to parasites, characterising their target(s) and/or designing analogs that are parasite-specific.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-016-1612-4) contains supplementary material, which is available to authorized users.

A higher aneurysmal subarachnoid hemorrhage incidence in women prior to menopause: a retrospective analysis of 4,895 cases from eight hospitals in China

BACKGROUND

Subarachnoid hemorrhage (SAH) from a ruptured cerebral aneurysm is a devastating disease. Despite the risk factors, including hypertension, cigarette smoking and alcohol use, are more common in men, aneurysmal SAH belongs to a few diseases which the incidence is higher in women than in men. Sex hormones, especially estrogen, might be protective against this condition. Hormone replacement therapy (HRT) seems to be associated with a reduced risk for aneurysmal SAH. This study aims to know the prevalence of aneurysmal SAH of men and women at different ages.

METHODS

The age and gender information of 4,895 case of aneurysmal SAH (3,016 females, 1,879 males) were collected retrospectively from eight institutions in mainland China. The prevalence of aneurysmal SAH of men and women at different ages was analyzed.

RESULTS

The data showed women had a higher incidence of aneurysmal SAH than men starting at late thirties, and men might have a higher incidence of aneurysmal SAH than women only before 37-year-old.

CONCLUSIONS

Menopause may not be the only dominant factor causing higher incidence of aneurysmal SAH in women than in men.