Estetrol and Mammary Gland: Friends or Foes?

Estetrol Inhibits Endometriosis Development in an In Vivo Murine Model

Endometriosis is characterized by the growth of endometrial-like tissue outside the uterus, and it is associated with alterations in the expression of hormone receptors and inflammation. Estetrol (E4) is a weak estrogen that recently has been approved for contraception. We evaluated the effect of E4 on the growth of endometriotic-like lesions and the expression of TNF-α, estrogen receptors (ERs), and progesterone receptors (PRs) in an in vivo murine model. Endometriosis was induced surgically in female C57BL/6 mice. E4 was delivered via Alzet pump (3 mg/kg/day) from the 15th postoperative day for 4 weeks. E4 significantly reduced the volume (p < 0.001) and weight (p < 0.05) of ectopic lesions. Histologically, E4 did not affect cell proliferation (PCNA immunohistochemistry) but it did increase cell apoptosis (TUNEL assay) (p < 0.05). Furthermore, it modulated oxidative stress (SOD, CAT, and GPX activity, p < 0.05) and increased lipid peroxidation (TBARS/MDA, p < 0.01). Molecular analysis showed mRNA (RT-qPCR) and protein (ELISA) expression of TNF-α decreased (p < 0.05) and mRNA expression of Esr2 reduced (p < 0.05), in contrast with the increased expression of Esr1 (p < 0.01) and Pgr (p < 0.05). The present study demonstrates for the first time that E4 limited the development and progression of endometriosis in vivo.

Estetrol/GPER/SERPINB2 transduction signaling inhibits the motility of triple-negative breast cancer cells

BACKGROUND

Estetrol (E4) is a natural estrogen produced by the fetal liver during pregnancy. Due to its favorable safety profile, E4 was recently approved as estrogenic component of a new combined oral contraceptive. E4 is a selective ligand of estrogen receptor (ER)α and ERβ, but its binding to the G Protein-Coupled Estrogen Receptor (GPER) has not been described to date. Therefore, we aimed to explore E4 action in GPER-positive Triple-Negative Breast Cancer (TNBC) cells.

METHODS

The potential interaction between E4 and GPER was investigated by molecular modeling and binding assays. The whole transcriptomic modulation triggered by E4 in TNBC cells via GPER was explored through high-throughput RNA sequencing analyses. Gene and protein expression evaluations as well as migration and invasion assays allowed us to explore the involvement of the GPER-mediated induction of the plasminogen activator inhibitor type 2 (SERPINB2) in the biological responses triggered by E4 in TNBC cells. Furthermore, bioinformatics analysis was aimed at recognizing the biological significance of SERPINB2 in ER-negative breast cancer patients.

RESULTS

After the molecular characterization of the E4 binding capacity to GPER, RNA-seq analysis revealed that the plasminogen activator inhibitor type 2 (SERPINB2) is one of the most up-regulated genes by E4 in a GPER-dependent manner. Worthy, we demonstrated that the GPER-mediated increase of SERPINB2 is engaged in the anti-migratory and anti-invasive effects elicited by E4 in TNBC cells. In accordance with these findings, a correlation between SERPINB2 levels and a good clinical outcome was found in ER-negative breast cancer patients.

CONCLUSIONS

Overall, our results provide new insights into the mechanisms through which E4 can halt migratory and invasive features of TNBC cells.

Experts' view on the role of oestrogens in combined oral contraceptives: emphasis on oestetrol (E4)

Introduction

The evolution of contraception has been crucial for public health and reproductive well-being. Over the past 60 years, combined oral contraceptives (COCs) have remained an important part of the contraceptive landscape worldwide; continued development has worked toward maintaining efficacy and improving safety.

Methods

Seven global experts convened to discuss the clinical relevance of the oestrogen in COCs, focusing on the impact of the new oestrogen, oestetrol (E4). Participants then commented through an online forum on the summary content and other participants' feedback. We prepared this report to describe the experts' views, their follow-up from the open forum and the evidence supporting their views.

Results

Ethinylestradiol (EE) and oestradiol (E2) affect receptors similarly whereas E4 has differential effects, especially in the liver and breast. Adequate oestrogen doses in COCs ensure regular bleeding and user acceptability. EE and E4 have longer half-lives than E2; accordingly, COCs with EE and E4 offer more predictable bleeding than those with E2. Oestrogen type and progestin influence VTE risk; E2 poses a lower risk than EE; although promising, E4/DRSP VTE risk is lacking population-based data. COCs alleviate menstrual symptoms, impact mental health, cognition, libido, skin, and bone health.

Conclusion

Oestrogens play an important role in the contraceptive efficacy, bleeding patterns, and overall tolerability/safety of COCs. Recent studies exploring E4 combined with DRSP show promising results compared to traditional formulations, but more definitive conclusions await further research.

Hormonal and natural contraceptives: a review on efficacy and risks of different methods for an informed choice

The debate about contraception has become increasingly important as more and more people seek safe and effective contraception. More than 1 billion women of reproductive age worldwide need a method of family planning, and wellbeing, socio-economic status, culture, religion and more influence the reasons why a woman may ask for contraception. Different contraceptive methods exist, ranging from 'natural methods' (fertility awareness-based methods - FABMs) to barrier methods and hormonal contraceptives (HCs). Each method works on a different principle, with different effectiveness.FABMs and HCs are usually pitted against each other, although it's difficult to really compare them. FABMs are a valid alternative for women who cannot or do not want to use hormone therapy, although they may have a high failure rate if not used appropriately and require specific training. HCs are commonly used to address various clinical situations, although concerns about their possible side effects are still widespread. However, many data show that the appropriate use of HC has a low rate of adverse events, mainly related to personal predisposition.The aim of this review is to summarize the information on the efficacy and safety of FABMs and HCs to help clinicians and women choose the best contraceptive method for their needs.

Combined oral contraceptive with estetrol plus drospirenone: from pharmacokinetics to clinical applications

INTRODUCTION

Drospirenone/estetrol (DRSP/E4) is a combined oral contraceptive (COC) recently approved in several countries. It is composed of 15 mg of E4, a natural estrogen produced by human fetal liver throughout pregnancy, and 3 mg of DRSP, the first synthetic progestin used in oral contraception derived from 17-α-spirolactone. E4 and DRSP synergistically prevent pregnancy by inhibiting ovulation. E4 differs from 17-β-estradiol or ethinylestradiol because it represents a native estrogen with selective action in tissues (NEST), therefore it displays both agonist and antagonist estrogenic effects in different tissues.

AREAS COVERED

In this paper, we reviewed the scientific literature published in English prior to April 2023 and gathered information on the pharmacodynamics and pharmacokinetics of DRSP, E4 and their combination for contraception. We also proposed possible clinical applications based on the characteristics of the components of this COC.

EXPERT OPINION

E4/DRSP-based COC has shown high tolerability, safety and satisfaction and may represent a viable choice in young girls in need of oral contraception and pill users who suffer from high cholesterol, breast tenderness or water retention. Moreover, this new COC shows higher scheduled bleeding rate compared to other pills containing natural estrogens. All the data are reassuring, permitting long-term use.

Tailoring Potential Natural Compounds for the Treatment of Luminal Breast Cancer

Breast cancer (BC) is the most diagnosed cancer worldwide, mainly affecting the epithelial cells from the mammary glands. When it expresses the estrogen receptor (ER), the tumor is called luminal BC, which is eligible for endocrine therapy with hormone signaling blockade. Hormone therapy is essential for the survival of patients, but therapeutic resistance has been shown to be worrying, significantly compromising the prognosis. In this context, the need to explore new compounds emerges, especially compounds of plant origin, since they are biologically active and particularly promising. Natural products are being continuously screened for treating cancer due to their chemical diversity, reduced toxicity, lower side effects, and low price. This review summarizes natural compounds for the treatment of luminal BC, emphasizing the activities of these compounds in ER-positive cells. Moreover, their potential as an alternative to endocrine resistance is explored, opening new opportunities for the design of optimized therapies.

Estrogen Receptor Signaling in Breast Cancer

Estrogen receptor (ER) signaling is a critical regulator of cell proliferation, differentiation, and survival in breast cancer (BC) and other hormone-sensitive cancers. In this review, we explore the mechanism of ER-dependent downstream signaling in BC and the role of estrogens as growth factors necessary for cancer invasion and dissemination. The significance of the clinical implications of ER signaling in BC, including the potential of endocrine therapies that target estrogens' synthesis and ER-dependent signal transmission, such as aromatase inhibitors or selective estrogen receptor modulators, is discussed. As a consequence, the challenges associated with the resistance to these therapies resulting from acquired ER mutations and potential strategies to overcome them are the critical point for the new treatment strategies' development.

Drospirenone and estetrol: evaluation of a newly approved novel oral contraceptive

INTRODUCTION

Estetrol (E4) is a native estrogen produced only by the fetal liver during pregnancy. E4 is the first new estrogen to be used in hormonal contraception since the introduction of oral contraceptives in 1960. Ethinyl estradiol, the most commonly used estrogen in oral contraceptives today, increases the risks of thromboembolism and has other significant hepatic impacts, which induce important drug-drug interactions. On the other hand, Phase 2 E4 characterization studies demonstrated that E4 has negligible impacts on liver, breast, and vascular endothelium due to its distinct tissue selectivity. Combined with drospirenone (DRSP), E4 offers an improved safety profile for oral contraception.

AREAS COVERED

This paper briefly highlights the unique pharmacokinetic and pharmacodynamic features of E4. The efficacy, safety, and tolerability results from the Phase 2 and 3 studies of the E4/DRSP pill are discussed to provide the reader with a thorough understanding of E4 and information to use when counseling potential users.

EXPERT OPINION

The estetrol/drospirenone oral contraceptive is effective and well tolerated and provides good cycle control. In the future, estetrol may be the estrogen of choice if subsequent evidence verifies that it reduces the risks associated with current estrogens, such as venous thromboembolism and drug-drug interactions.

Estetrol Increases Progesterone Genetic Response without Triggering Common Estrogenic Effects in Endometriotic Cell Lines and Primary Cultures

Estetrol (E4), a natural estrogen produced by the human fetal liver, is actively studied for menopause and breast cancer treatment. It has low side effects and preferential estrogen receptor alpha (ERα) affinity. There are no data about its effects on endometriosis, a common gynecological disease affecting 6-10% of cycling women, generating painful pelvic lesions and infertility. Current combined hormone treatment (progestins and estrogens) is safe and efficient; nevertheless, one-third of patients develop progesterone (P4) resistance and recurrence by reducing P4 receptors (PRs) levels. We aimed to compare E4 and 17β-estradiol (E2) effects using two human endometriotic cell lines (epithelial 11Z and stromal Hs832 cells) and primary cultures from endometriotic patients. We evaluated cell growth (MTS), migration (wound assay), hormone receptors levels (Western blot), and P4 response by PCR array. Compared to E2, E4 did not affect cell growth or migration but increased estrogen receptor alpha (ERα) and PRs, and reduced ERβ. Finally, the incubation with E4 improved the P4 gene response. In conclusion, E4 increased PRs levels and genetic response without inducing cell growth or migration. These results suggest that E4 might be useful for endometriosis treatment avoiding P4 resistance; however, evaluating its response in more complex models is required.

Estrogeni e infiammazione

L’infiammazione è un processo essenziale per la vita, modulato da meccanismi immunoneuroendocrini. In questa Rassegna si analizza il ruolo degli estrogeni naturali umani (estradiolo, estrone, estriolo ed estetrolo) nella regolazione dell’infiammazione, facendo riferimento alla loro interazione con gli altri steroidi sessuali (progesterone e androgeni) nella modulazione di tale processo. L’infiammazione può essere fisiologica, quando è finalizzata (resolving), di breve durata, di intensità limitata e termina con restitutio ad integrum. È patologica quando perde tali caratteristiche diventando non finalizzata, non risolutiva (non resolving), di variabile intensità, con andamento cronico e progressiva distruzione tissutale. Durante la vita fertile della donna si manifestano tre eventi infiammatori fisiologici pertinenti alla sfera riproduttiva: l’ovulazione, la mestruazione e il parto. Tutti e tre sono strettamente correlati con le oscillazioni dei livelli di estrogeni, nonché del progesterone e degli androgeni. L’azione degli estrogeni nei confronti dell’infiammazione è molto articolata, in rapporto al tipo di estrogeno considerato, all’andamento dei suoi livelli plasmatici (fluttuante versus stabile) e al tipo di interazione con i recettori estrogenici, in particolare di tipo \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\alpha $\end{document}α e \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\beta $\end{document}β. Le fluttuazioni estrogeniche, in particolare dell’estradiolo, influiscono sulla presenza e l’attivazione delle varie classi di cellule immunitarie nell’endometrio e a livello sistemico. Accanto agli estrogeni, progesterone e androgeni rivestono un ruolo immunomodulatorio, con prevalenza anti-infiammatoria. La concisa descrizione delle complesse interazioni tra i diversi tipi di estrogeni e il sistema immunitario è stata fatta privilegiando gli aspetti più attinenti alla pratica clinica quotidiana dell’endocrinologo/a.

Estetrol: A New Choice for Contraception

Estetrol (E4) is a natural estrogenic steroid that is normally produced by human fetal liver. Recent research has demonstrated that it is a potent, orally bioavailable, natural selective estrogen receptor modulator; it has a moderate affinity for both human estrogen receptor alpha (ERα) and ERβ, with a preference for ERα. Clinical studies have demonstrated possible use as an estrogen in combined oral contraceptives (COC). COCs containing E4 and drospirenone (DRSP) showed a high acceptability, tolerability, and user satisfaction also when compared to COCs containing ethinylestradiol (EE). E4/DRSP effectively inhibits ovulation, with a similar effect on endometrium thickness than that of EE-containing COCs. Low doses (15 mg) of E4 with DRSP (3 mg) showed promising results in term of bleeding pattern and cycle control, also when compared to other COCs containing synthetic estrogens. Moreover, the association has limited effects on serum lipids, liver, SHBG levels, and carbohydrate metabolism. This combination also could drive a lower risk of venous thromboembolism than EE-containing COCs. In this review, we will summarize the actual knowledge about the new E4-containing contraceptive. Further large-scale studies in the full target population are needed to provide more insights into the cardiovascular safety profile and user satisfaction of E4/DRSP.