Gonadotrophin-releasing hormone (GnRH) and GnRH agonists: mechanisms of action

A comprehensive review of the new FIGO classification of ovulatory disorders

BACKGROUND

The World Health Organization (WHO) system for the classification of disorders of ovulation was produced 50 years ago and, by international consensus, has been updated by the International Federation of Gynecology and Obstetrics (FIGO).

OBJECTIVE AND RATIONALE

This review outlines in detail each component of the FIGO HyPO-P (hypothalamic, pituitary, ovarian, PCOS) classification with a concise description of each cause, and thereby provides a systematic method for diagnosis and management.

SEARCH METHODS

We searched the published articles in the PubMed database in the English-language literature until October 2022, containing the keywords ovulatory disorders; ovulatory dysfunction; anovulation, and each subheading in the FIGO HyPO-P classification. We did not include abstracts or conference proceedings because the data are usually difficult to assess.

OUTCOMES

We present the most comprehensive review of all disorders of ovulation, published systematically according to the logical FIGO classification.

WIDER IMPLICATIONS

Improving the diagnosis of an individual's ovulatory dysfunction will significantly impact clinical practice by enabling healthcare practitioners to make a precise diagnosis and plan appropriate management.

Fertility Preservation in the Era of Immuno-Oncology: Lights and Shadows

In recent years, immuno-oncology has revolutionized the cancer treatment field by harnessing the immune system's power to counteract cancer cells. While this innovative approach holds great promise for improving cancer outcomes, it also raises important considerations related to fertility and reproductive toxicity. In fact, most young females receiving gonadotoxic anti-cancer treatments undergo iatrogenic ovarian exhaustion, resulting in a permanent illness that precludes the vocation of motherhood as a natural female sexual identity. Although commonly used, oocyte cryopreservation for future in vitro fertilization and even ovarian cortex transplantation are considered unsafe procedures in cancer patients due to their oncogenic risks; whereas, ovarian stem cells might support neo-oogenesis, providing a novel stemness model of regenerative medicine for future fertility preservation programs in oncology. Recent scientific evidence has postulated that immune checkpoint inhibitors (ICIs) might in some way reduce fertility by inducing either primary or secondary hypogonadism, whose incidence and mechanisms are not yet known. Therefore, considering the lack of data, it is currently not possible to define the most suitable FP procedure for young patients who are candidates for ICIs. In this report, we will investigate the few available data concerning the molecular regulation of ICI therapy and their resulting gonadal toxicity, to hypothesize the most suitable fertility preservation strategy for patients receiving these drugs.

IGFBP1a is a nutrient deficient response factor that can inhibit fish reproduction through the hypothalamus-pituitary-ovary axis†

Reproduction is a high energy consuming process, so long-term malnutrition can significantly inhibit gonadal development. However, little is known about the molecular mechanism by which fasting inhibits reproduction. Our present study found that fasting could dramatically induce insulin-like growth factor binding protein 1 (IGFBP1) expression in the liver, hypothalamus, pituitary and ovaries of grass carp. In addition, IGFBP1a in the hypothalamus-pituitary-gonad axis could inhibit the development of gonads. These results indicated that fasting may participate in the regulation of fish gonadal development through the mediation of IGFBP1a. Further studies found that IGFBP1a could markedly inhibit gonadotropin-releasing hormone 3 expressions in hypothalamus cells. At the pituitary level, IGFBP1a could significantly reduce the gonadotropin hormones (LH and FSH) expression by blocking the action of pituitary insulin-like growth factor 1. Interestingly, IGFBP1a could also directly inhibit the expression of lhr, fshr, and sex steroid hormone synthase genes (cyp11a, cyp17a, and cyp19a1) in the ovary. These results indicated that IGFBP1a should be a nutrient deficient response factor that could inhibit fish reproduction through the hypothalamus-pituitary-ovary axis.

Minerals and the Menstrual Cycle: Impacts on Ovulation and Endometrial Health

The role of minerals in female fertility, particularly in relation to the menstrual cycle, presents a complex area of study that underscores the interplay between nutrition and reproductive health. This narrative review aims to elucidate the impacts of minerals on key aspects of the reproductive system: hormonal regulation, ovarian function and ovulation, endometrial health, and oxidative stress. Despite the attention given to specific micronutrients in relation to reproductive disorders, there is a noticeable absence of a comprehensive review focusing on the impact of minerals throughout the menstrual cycle on female fertility. This narrative review aims to address this gap by examining the influence of minerals on reproductive health. Each mineral's contribution is explored in detail to provide a clearer picture of its importance in supporting female fertility. This comprehensive analysis not only enhances our knowledge of reproductive health but also offers clinicians valuable insights into potential therapeutic strategies and the recommended intake of minerals to promote female reproductive well-being, considering the menstrual cycle. This review stands as the first to offer such a detailed examination of minerals in the context of the menstrual cycle, aiming to elevate the understanding of their critical role in female fertility and reproductive health.

Meta-analysis of trigger timing in normal responders undergoing GnRH antagonist ovarian hyperstimulation protocol

IMPORTANCE

The first meta-analysis focused only on gonadotropin-releasing hormone (GnRH) antagonists, which helped determine the effect of delay trigger on pregnancy outcomes.

OBJECTIVE

To evaluate the impact of delay trigger compared with standard trigger in normal responders undergoing GnRH antagonist protocol in improving pregnancy outcomes.

METHODS

Studies published before April 2023 in PubMed, EMBASE, Cochrane Library, Web of Science, CNKI, Wanfang, VIP and CBM databases were searched. Randomized controlled trials (RCTs) and cohort studies conducted in normal responders reporting the efficacy of delay trigger using GnRH antagonist protocol were included. Data were combined to calculate mean differences (MD) for continuous variables and odd ratios (OR) for categorical variables with their corresponding 95% confidence intervals (CIs). Heterogeneity was assessed using Cochran's Q test.

RESULTS

Endpoints, including clinical pregnancy rate (CPR), live birth rate (LBR), the number of oocyte retrievals and embryos, and fertilization rate, were analyzed. Six (6) clinical studies (4 RCTs and 2 cohort studies) with 1,360 subjects were included. The pooled results showed that the number of oocyte retrievals (MD: 1.20, 95% CI: 1.10, 1.30, p < 0.01), fertilization rate (MD: 0.64, 95% CI: 0.29, 0.99, p < 0.01) and days of stimulation (MD: 0.95; 95% CI: 0.54, 1.37; p < 0.01) in the delay trigger group was significantly higher than that in the standard trigger group. However, there was no significant difference in the number of embryos (MD: 0.19, 95% CI: -0.29, 0.67, p = 0.44), CPR (OR: 1.12; 95% CI: 0.72, 1.75; p = 0.062), and LBR (OR: 1.23; 95% CI: 0.90, 1.66; p = 0.19) between the two trigger groups.

CONCLUSION

Delaying trigger time in GnRH antagonist protocol increased the number of oocytes retrieved but not the number of embryos. Furthermore, delay trigger shot was not associated with a clinical benefit towards CPR and LBR in women who underwent fresh embryo transfer cycles.

TRIAL REGISTRATION

The International Prospective Register of Systematic Reviews (PROSPERO), registration number: CRD42023413217.

GnRH analogs induce a LH peak and increase pregnancy per timed-AI in ewes

To date, there have been no studies testing the capacity of GnRH analogs and respective doses to induce a LH peak in sheep. In this sense, the present study aimed to evaluate the capacity of different synthetic forms and doses of GnRH in inducing LH release in sheep, and the effect of GnRH administration at timed artificial insemination (TAI) on pregnancy per timed-AI. In experiment 1, ewes (n = 40) received an intravaginal device (IVD) of medroxyprogesterone acetate (MPA; 60 mg) for 7 d and prostaglandin F2α analog on Day 5. On Day 7, the ewes were allocated randomly into one of eight groups (n = 5/group), which received a GnRH analog at a specific dose, as follows: lecirelin (12.5 or 25 μg), gonadorelin (50 or 100 μg), buserelin acetate (4.2 or 8.4 μg), or deslorelin (375 or 750 μg). Blood samples for LH determination were obtained at 0, 2, 4, and 6 h after GnRH and the IVDs were removed after the last blood collection. The maximal LH concentration induced by gonadorelin at doses of 50 μg and 100 μg (12.0 ± 2.4 ng/mL and 28.6 ± 7.1 ng/mL, respectively) was lower (P < 0.05) than serum LH induced by 8.4 μg of buserelin (78.9 ± 12.9 ng/mL), 375 μg and 750 μg of deslorelin (75.6 ± 7.4 ng/mL and 72.1 ± 10.6 ng/mL, respectively) and 12.5 μg and 25 μg of lecirelin (73.3 ± 17.8 ng/mL and 61.6 ± 5.9 ng/mL, respectively). However, the maximal LH concentration induced by 4.2 μg of buserelin (49.4 ± 5.9 ng/mL) was similar (P > 0.05) to the 100 μg of gonadorelin. The total release of LH (area under the curve - AUC) after treatment with 50 μg of gonadorelin (31.7 ± 5.9 ng h/mL) was lower (P < 0.05) than after other agonists. In a second experiment, 330 ewes were treated with IVD containing MPA for 7 d. Simultaneously with IVD removal, 250 μg of cloprostenol and 200 IU of eCG were administered. Then, ewes were assigned randomly to either no further treatment (control); or to receive 4.2 μg of buserelin acetate (GnRH group) at cervical TAI, which was performed with fresh semen 54 h after IVD withdrawal in all the animals. Higher pregnancy per timed-AI was observed for GnRH (50.3 %) compared to control (40.7 %). We conclude that buserelin acetate (8.4 μg), lecirelin (12.5 and 25 μg) and deslorelin (375 and 750 μg) induced a greater stimulatory effect on LH secretion than gonadorelin treatment. Furthermore, buserelin acetate treatment at TAI increased pregnancy per timed-AI in ewes previously treated with MPA and eCG.

Bone quality following peripubertal growth in a mouse model of transmasculine gender-affirming hormone therapy

During peri-puberty, bone growth and the attainment peak bone mass is driven predominantly by sex steroids. This is important when treating transgender and gender diverse youth, who have become increasingly present at pediatric clinics. Analogues of gonadotropin-releasing hormone (GnRH) are commonly prescribed to transgender and gender diverse youth prior to starting gender-affirming hormone therapy (GAHT). However, the impact of GnRH agonists on long bones with the addition of GAHT is relatively unknown. To explore this, we developed a trans-masculine model by introducing either GnRHa or vehicle treatment to female-born mice at a pre-pubertal age. This treatment was followed by male GAHT (testosterone, T) or control treatment three weeks later. Six weeks after T therapy, bone quality was compared between four treatment groups: Control (vehicle only), GnRHa-only, GnRHa + T, and T-only. Bone length/size, bone shape, mechanical properties, and trabecular morphology were modulated by GAHT. Independent of GnRHa administration, mice treated with T had shorter femurs, larger trabecular volume and increased trabecular number, higher trabecular bone mineral density, and wider superstructures on the surface of bone (e.g., third trochanters) when compared to control or GnRHa-only mice. In conclusion, prolonged treatment of GnRHa with subsequent GAHT treatment directly affect the composition, parameters, and morphology of the developing long bone. These findings provide insight to help guide clinical approaches to care for transgender and gender diverse youth.

Gonadotropin-Releasing Hormone Receptor (GnRHR) and Hypogonadotropic Hypogonadism

Human sexual and reproductive development is regulated by the hypothalamic-pituitary-gonadal (HPG) axis, which is primarily controlled by the gonadotropin-releasing hormone (GnRH) acting on its receptor (GnRHR). Dysregulation of the axis leads to conditions such as congenital hypogonadotropic hypogonadism (CHH) and delayed puberty. The pathophysiology of GnRHR makes it a potential target for treatments in several reproductive diseases and in congenital adrenal hyperplasia. GnRHR belongs to the G protein-coupled receptor family and its GnRH ligand, when bound, activates several complex and tissue-specific signaling pathways. In the pituitary gonadotrope cells, it triggers the G protein subunit dissociation and initiates a cascade of events that lead to the production and secretion of the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) accompanied with the phospholipase C, inositol phosphate production, and protein kinase C activation. Pharmacologically, GnRHR can be modulated by synthetic analogues. Such analogues include the agonists, antagonists, and the pharmacoperones. The agonists stimulate the gonadotropin release and lead to receptor desensitization with prolonged use while the antagonists directly block the GnRHR and rapidly reduce the sex hormone production. Pharmacoperones include the most recent GnRHR therapeutic approaches that directly correct the misfolded GnRHRs, which are caused by genetic mutations and hold serious promise for CHH treatment. Understanding of the GnRHR's genomic and protein structure is crucial for the most appropriate assessing of the mutation impact. Such mutations in the GNRHR are linked to normosmic hypogonadotropic hypogonadism and lead to various clinical symptoms, including delayed puberty, infertility, and impaired sexual development. These mutations vary regarding their mode of inheritance and can be found in the homozygous, compound heterozygous, or in the digenic state. GnRHR expression extends beyond the pituitary gland, and is found in reproductive tissues such as ovaries, uterus, and prostate and non-reproductive tissues such as heart, muscles, liver and melanoma cells. This comprehensive review explores GnRHR's multifaceted role in human reproduction and its clinical implications for reproductive disorders.

Combined Therapy with Anthracyclines and GnRH Analogues for Breast Cancer: Impact on Ischemic Heart Disease

The combination of classic chemotherapy agents like anthracyclines with novel targeted medications has had a positive impact on women's survival from breast cancer. GnRH analogues are primarily employed to temporarily suppress ovarian function in premenopausal women with hormone-receptor-positive (HR+) breast cancer. Despite their benefits, the true degree of their collateral effects has been widely understudied, especially when it comes to ischemic heart disease. This review aims at summarizing the current state of the art on this issue, with particular focus on the risk for cardiotoxicity associated with the combined use of GnRH analogues and anthracyclines.

Testosterone Restores Body Composition, Bone Mass, and Bone Strength Following Early Puberty Suppression in a Mouse Model Mimicking the Clinical Strategy in Trans Boys

Transgender youth increasingly present at pediatric gender services. Some of them receive long-term puberty suppression with gonadotropin-releasing hormone analogues (GnRHa) before starting gender-affirming hormones (GAH). The impact of GnRHa use started in early puberty on bone composition and bone mass accrual is unexplored. It is furthermore unclear whether subsequent GAH fully restore GnRHa effects and whether the timing of GAH introduction matters. To answer these questions, we developed a mouse model mimicking the clinical strategy applied in trans boys. Prepubertal 4-week-old female mice were treated with GnRHa alone or with GnRHa supplemented with testosterone (T) from 6 weeks (early puberty) or 8 weeks (late puberty) onward. Outcomes were analyzed at 16 weeks and compared with untreated mice of both sexes. GnRHa markedly increased total body fat mass, decreased lean body mass, and had a modest negative impact on grip strength. Both early and late T administration shaped body composition to adult male levels, whereas grip strength was restored to female values. GnRHa-treated animals showed lower trabecular bone volume and reduced cortical bone mass and strength. These changes were reversed by T to female levels (cortical bone mass and strength) irrespective of the time of administration or even fully up to adult male control values (trabecular parameters) in case of earlier T start. The lower bone mass in GnRHa-treated mice was associated with increased bone marrow adiposity, also reversed by T. In conclusion, prolonged GnRHa use started in prepubertal female mice modifies body composition toward more fat and less lean mass and impairs bone mass acquisition and strength. Subsequent T administration counteracts GnRHa impact on these parameters, shaping body composition and trabecular parameters to male values while restoring cortical bone architecture and strength up to female but not male control levels. These findings could help guide clinical strategies in transgender care. © 2023 American Society for Bone and Mineral Research (ASBMR).

GnRH agonists and antagonists in therapy of symptomatic uterine fibroids - current roles and future perspectives

INTRODUCTION

Uterine fibroids are the most common noncancerous tumors in women of childbearing age. This review was developed to evaluate the current role of gonadotropin-releasing hormone (GnRH) agonists and antagonists in the therapy of symptomatic uterine fibroids.

AREAS COVERED

There is a great need for alternative methods for surgical treatment of uterine fibroids. Hormonal therapy remains the first-line treatment option for most patients. GnRH analogs (agonists and antagonists) modulate the pulsatile release of GnRH. This review summarizes the available literature concerning pharmacologic principles underlying the mechanism of action of GnRH and its analogs, as well as individual therapeutic applications to which these drugs have been applied.

EXPERT OPINION

In many cases, it is possible to try to treat uterine fibroids pharmacologically. Both groups of GnRH analogs are used in therapy, agonists instead as a preparation for surgery, and antagonists as a drug for long-term use. It is essential to develop this path further and look for at least long-term-release systems or new methods of administering these drugs. It is also important from the patient's perspective to search for possible drugs that may have an additive effect of decreasing side effects when combined with GnRH analogs.

The Intersection of Prostate Cancer and Hypertension: a Call to Action

OPINION STATEMENT

With improvements in treatment and survival from prostate cancer, comorbid cardiac conditions will significantly impact overall morbidity and mortality from prostate cancer. Hypertension is a well-established cardiovascular risk factor that increases the risk of heart failure, myocardial infarction, and stroke. Therapies used in the treatment of prostate cancer, including GnRH agonists, GnRH antagonists, enzalutamide, abiraterone, and others, can directly or indirectly increase the risk of hypertension. In this paper, we review the evidence available on the incidence and mechanism of hypertension in prostate cancer patients. In addition, we provide recommendations on the assessment, treatment, and future directions for hypertension management in the prostate cancer population. We propose an individualized goal for blood pressure in prostate cancer patients, balancing the target goal of 130/80 mmHg with common comorbidities of frailty, orthostatic symptoms, and imbalance in this population. The presence of additional comorbidities (myocardial infarction, heart failure, renal disease, diabetes) can assist in preference of anti-hypertensive drugs.

The role of androgens in pressure overload myocardial hypertrophy

Pressure overload hypertrophy of the left ventricle is a common result of many cardiovascular diseases. Androgens show anabolic effects in skeletal muscles, but also in myocardial hypertrophy. We carefully reviewed literature regarding possible effects of androgens on specific left ventricular hypertrophy in pressure overload conditions excluding volume overload conditions or generel sex differences.

Impact of Adenomyosis on Infertile Patients-Therapy Options and Reproductive Outcomes

Adenomyosis is associated with a negative impact on reproductive outcomes. Although adenomyosis is detected more frequently in women of late reproductive age, its impact on pregnancy rates is important because, in today's world, family planning has shifted towards the late reproductive phase of life for many women. Although the diagnostic indications for imaging studies are well-known, we lack strict diagnostic criteria and classification systems concerning the extent of the disease. Selecting the optimal evidence-based treatment option for adenomyosis is difficult because of the paucity of evidence concerning the association between fertility and the degree and composition of adenomyosis. Furthermore, the treatment of infertility might interfere with the treatment of adenomyosis due to the presence of pain. The aim of this review is to analyze the association between adenomyosis and infertility, and describe treatment options to enhance reproductive outcomes. The following aspects will be addressed in detail: (a) prevalence and causes of adenomyosis, (b) diagnostic tools with imaging techniques, (c) clinical symptoms, (d) proposed pathomechanism of adenomyosis and infertility, and (e) different treatment approaches (pharmacological, surgical, others) and their impact on reproductive outcomes.

Benefits from the first year of GnRHa therapy in boys with idiopathic central precocious puberty when initiating treatment after age 9 years: findings from a real-world retrospective study

BACKGROUND

GnRHa treatment was established for improving final adult height (FAH) in children presenting with Idiopathic central precocious puberty (ICPP) up to age 8, while several controversies remained for older age groups. The primary objective was to evaluate whether boys diagnosed with ICPP over 9 years of chronological age (CA) could achieve a height benefit from GnRHa treatment.

METHODS

We retrospectively evaluated the medical records of 23 boys treated for idiopathic central precocious puberty between January 2018 and January 2021 at Jiangsu Children's Medical Center. All patients started treatment with intramuscular depot GnRHa at a dose of 80-100 μg/kg, followed by continuous intramuscular injection every 28 days at a dose of 60-80 μg/kg. The hormonal parameters, bone age/chronological age ratio, FAH, growth velocity (GV), tanner staging and body mass index (BMI) were assessed during the treatment period.

RESULTS

After one course of treatment (3 months), the basal FSH and testosterone levels were reduced, while the basal LH value was not significantly changed compared with those before treatment. Furthermore, the mean BA/CA ratio reduction was statistically significant at month 12. The mean PAH following administration of GnRHa after 12 months was statistically improved compared with those at baseline. In addition, the clinical sign of puberty and GV were significantly improved and the BMI remained unchanged as desired at month 12.

CONCLUSIONS

This analysis highlighted the positive outcome on the decrease in the rate of bone maturation, with a favorable effect on progression of clinical signs of puberty. Furthermore, our study confirmed PAH was improved even in the older children at onset of treatment (ages 9-10), emphasizing the importance of personalized treatment in such population.

Use of gonadotropin-releasing hormone agonists for ovarian preservation in patients receiving cyclophosphamide for systemic lupus erythematosus: A meta-analysis

BACKGROUND

Cyclophosphamide (CYC) has known cytotoxic effects on ovarian reserve and has been linked to premature ovarian failure (POF) in systemic lupus erythematosus (SLE). The concurrent use of gonadotropin-releasing hormone agonists (GnRHas) is postulated to preserve ovarian function by reducing the number of follicles exposed to CYC, but there is paucity of data to establish its efficacy. We conducted a meta-analysis to summarize the effect of concurrent GnRHa use in persevering ovarian function and pregnancy.

METHODS

English language databases of PubMed, Embase, and Cochrane were searched to include studies published between 2000 and 2021. Studies in females with rheumatic diseases receiving concurrent GnRHa and CYC therapy to evaluate ovarian preservation as defined by amenorrhea, follicle stimulating hormone (FSH), anti-mullerian hormone (AMH), or estradiol levels or successful pregnancy were included. We used a fixed effect, exact, Mantel-Haenszel approach to estimate the overall odds ratio (OR) and associated 95% confidence intervals (95% CIs).

RESULTS

Seven studies with 218 female patients were included. The ovarian function was preserved in 125/132 (94.6%) of women who received GnRHa concurrently with CYC compared to 50/86 (58%) of women who did not receive GnRHa (OR = 10.3, CI = 4.83-36.29). The OR for pregnancy with GnRHa use = 2.94 (CI = 1.04-9.89).

CONCLUSION

Our results based on limited published studies suggest that concurrent GnRHa use preserves ovarian function and increase odds of pregnancy. It can be considered for premenopausal SLE females receiving CYC. Long-term follow-up studies are needed to establish the efficacy and safety of GnRHa use for ovarian preservation.

Safety, pharmacokinetics, and pharmacodynamics of SHR7280, an oral gonadotropin-releasing hormone antagonist in healthy premenopausal women

Background: Treatment with gonadotropin-releasing hormone (GnRH) antagonists is a powerful strategy to suppress gonadotropin activity in women with sex hormone-dependent disorders. Herein, we provide the safety, pharmacokinetics (PK), and pharmacodynamics (PD) profiles of SHR7280, an oral non-peptide GnRH antagonist in healthy premenopausal women. Methods: In this randomized, double-blinded, placebo-controlled, dose-ascending, phase 1 trial, healthy premenopausal women were randomized to receive SHR7280 or placebo orally. Four doses of SHR7280 (200, 300, 400, and 500 mg BID) were planned. Safety, PK, and PD parameters were evaluated. Results: SHR7280 presented tolerable toxicity and most adverse events were mild in severity. SHR7280 showed rapid onset of action (median T_max ranged from 1.0 to 1.2 h for each dose), and plasma exposure was dose-dependent. PD results showed that SHR7280 300 mg BID and above suppressed estrogen concentration within the estradiol (E₂) treatment window for endometriosis (20-50 pg/ml), inhibited the emergence of the peak of luteinizing hormone (LH) and the concentration of follicle stimulating hormone (FSH), and maintained the concentration of progesterone (P) in an anovulatory state (2 nmol/L). Conclusion: SHR7280 showed favorable safety, PK, and PD profiles in the dose range of 200-500 mg BID in healthy premenopausal women. This study supports the continued clinical development of SHR7280 as a GnRH antagonist for sex hormone-dependent disorders in women. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT04554043, Identifier NCT04554043.

Pretreatment with gonadotropin-releasing hormone antagonist protects against chemotherapy-induced testicular damage 'in mice

Background

Testicular toxicity following chemotherapy is of increasing importance with the continuous improvement of survival rates. Gonadotropin-releasing hormone (GnRH) was suggested to protect testis against such toxicity; however, its suppressive quality and mechanism of action are still unclear. We examined whether and how pretreatment with GnRH antagonist protects against the testicular damage caused by chemotherapy.

Methods

Mature male mice were injected subcutaneously eight times in 2-day intervals with either saline or GnRH antagonist (Cetrotide; 1 g/mg), followed by an intraperitoneal injection with either saline or cyclophosphamide (CTX;100 mg/kg BW) and sacrificed 2 weeks or 3 months later. Testicular weight, epididymis weight, epididymal sperm count and sperm motility were measured. Serum anti-Müllerian hormone (AMH) was measured by enzyme-linked immunosorbent assay. Immunohistochemistry (Ki-67), immunofluorescence (PCNA, CD34), terminal transferase-mediated deoxyuridine 5-triphosphate nick-end labeling (TUNEL) and computerized analysis were performed to examine testicular proliferation, apoptosis and vascularization. Quantitative real-time PCR was used to assess the amount of spermatogonial reserve (Id4 and Gfra1 mRNAs).

Results

Pretreatment with GnRH antagonist transiently reduced testicular weight, epididymal weight, germinal proliferation and sperm count; it also abolished the permanent long-term effect of CTX on these parameters and prevented cyclophosphamide-induced testicular toxicity characterized by apoptosis and serum AMH increase and irreversible loss of spermatogonial reserve.

Conclusions

Our findings imply that pretreatment with GnRH antagonist temporarily reduces spermatogenesis and may be used as pretreatment for reducing chemotherapeutic testicular toxicity.

Whole course of treatment of autoimmune progesterone dermatitis that had spontaneously resolved during pregnancy: A case report and review of the literature

Anaphylaxis due to autoimmune progesterone dermatitis is a rare but severe allergic disease in women. The clinical manifestations of APD are diverse, and a proper understanding of the disease can help even diagnose and treat it. A case of autoimmune progesterone dermatitis related in our department is reported as follows. She developed a rash with severe pruritus that was highly consistent with her menstrual cycle without any trigger 10 years ago. Laboratory tests were unremarkable. But all the symptoms disappeared during her pregnancy and resurfaced after the miscarriage. Two years ago, after a positive progesterone intradermal test confirmed the diagnosis of PH, she was given mifepristone, contraceptives(OCPs), and skin embedding treatment, and her symptoms improved.

The roles of GnRH in the human central nervous system

It is widely known that GnRH plays a role in facilitating reproductive function via the HPG axis, and this was once believed to be its only function. However, over the last several decades important neuromodulatory roles of GnRH in multiple brain functions have been elucidated. Multiple GnRH isoforms and receptors have been detected outside the HPG-axis across different species. In this review, we focus on the human CNS where GnRH I and II isoforms and a functional GnRH I receptor have been isolated. We first describe the traditional understanding of GnRH within the hypothalamus and the pituitary and current clinical use of GnRH analogues. We then review the location and function of GnRH-producing neurons and receptors located outside the HPG axis. We next review the GnRH I and II neuron location and quantity and GnRH I receptor gene expression throughout the human brain, using the Allen Brain Map Atlas. This analysis demonstrates a wide expression of GnRH throughout the brain, including prominent expression in the basal forebrain and cerebellum. Lastly, we examine the potential role of GnRH in aging and inflammation and its therapeutic potential for neurodegenerative disease and spinal cord lesions.

Potassium Concentrations in Transgender Women Using Spironolactone: A Retrospective Chart Review

OBJECTIVES

To assess the incidence of hyperkalemia in transgender women using spironolactone retrospectively.

METHODS

This was a retrospective chart review of transgender women who received gender-affirming hormone therapy that included spironolactone from the endocrinology clinic between January 1, 2000 and September 6, 2018. The 44 subjects that had paired potassium levels documented and were on spironolactone were included and analyzed. Study outcomes included incidence of hyperkalemia (serum potassium >5.0 mmol/L), the relationship between duration and degree of hyperkalemia and difference between potassium concentrations at the beginning of spironolactone treatment vs last potassium concentration.

RESULTS

The median age of the subjects was 36.5 years. The cohort was predominantly of non- Hispanic white (32/44). No potassium level was above 5.5 mmol/ L and all subjects had creatinine < 2 mg/dL. The median duration of treatment was 25 months (range 2- 92 months) and a total of 140 potassium measurements were available. The mean potassium concentration (3.87 mmol/L) before the initiation of spironolactone wwas lower than the mean potassium concentration (4.03 mmol/L) while on spironolactone and the difference was statistically significant but clinically insignificant (mean difference 0.16 mmol/L, p=0.013). The regression beta i.e., average change in potassium concentration per one additional month of treatment duration was -00.1, 95% CI [-00.4, 0.01], p=0.255 which signified no relation between treatment duration and spironolactone use.

CONCLUSION

No subject had laboratory evidence of hyperkalemia after the initiation of spironolactone. Frequent measurement of potassium levels might be unnecessary in transgender women taking spironolactone, in patients with serum creatinine < 2 mg/dL.

Phloretin in Benign Prostate Hyperplasia and Prostate Cancer: A Contemporary Systematic Review

Currently, medication for benign prostate hyperplasia (BPH) and prostate cancer (PCa) are mainly based on modulating the hormone and nervous systems. However, side effects often affect patients, and might decrease their commitment to continuing the medication and lower their quality of life. Some studies have indicated that chronic inflammation might be the cause of BPH and PCa. Based on this hypothesis, the effect of phloretin, a potent anti-inflammatory and anti-oxidative flavonoid, has been researched since 2010. Results from animal and in-vitro studies, obtained from databases, also indicate that the use of phloretin in treating BPH and PCa is promising. Due to its effect on inflammatory cytokines, apoptosis or anti-apoptosis, reactive oxygen species, anti-oxidant enzymes and oxidative stress, phloretin is worthy of further study in human clinical trials regarding safety and effective dosages.

Epigenomic and enhancer dysregulation in uterine leiomyomas

BACKGROUND

Uterine leiomyomas, also known as uterine fibroids or myomas, are the most common benign gynecological tumors and are found in women of reproductive and postmenopausal age. There is an exceptionally high prevalence of this tumor in women by the age of 50 years. Black women are particularly affected, with an increased incidence, earlier age of onset, larger and faster growing fibroids and greater severity of symptoms as compared to White women. Although advances in identifying genetic and environmental factors to delineate these fibroids have already been made, only recently has the role of epigenomics in the pathogenesis of this disease been considered.

OBJECTIVE AND RATIONALE

Over recent years, studies have identified multiple epigenomic aberrations that may contribute to leiomyoma development and growth. This review will focus on the most recent discoveries in three categories of epigenomic changes found in uterine fibroids, namely aberrant DNA methylation, histone tail modifications and histone variant exchange, and their translation into altered target gene architecture and transcriptional outcome. The findings demonstrating how the altered 3D shape of the enhancer can regulate gene expression from millions of base pairs away will be discussed. Additionally, translational implications of these discoveries and potential roadblocks in leiomyoma treatment will be addressed.

SEARCH METHODS

A comprehensive PubMed search was performed to identify published articles containing keywords relevant to the focus of the review, such as: uterine leiomyoma, uterine fibroids, epigenetic alterations, epigenomics, stem cells, chromatin modifications, extracellular matrix [ECM] organization, DNA methylation, enhancer, histone post-translational modifications and dysregulated gene expression. Articles until September 2021 were explored and evaluated to identify relevant updates in the field. Most of the articles focused on in the discussion were published between 2015 and 2021, although some key discoveries made before 2015 were included for background information and foundational purposes. We apologize to the authors whose work was not included because of space restrictions or inadvertent omission.

OUTCOMES

Chemical alterations to the DNA structure and of nucleosomal histones, without changing the underlying DNA sequence, have now been implicated in the phenotypic manifestation of uterine leiomyomas. Genome-wide DNA methylation analysis has revealed subsets of either suppressed or overexpressed genes accompanied by aberrant promoter methylation. Furthermore, differential promoter access resulting from altered 3D chromatin structure and histone modifications plays a role in regulating transcription of key genes thought to be involved in leiomyoma etiology. The dysregulated genes function in tumor suppression, apoptosis, angiogenesis, ECM formation, a variety of cancer-related signaling pathways and stem cell differentiation. Aberrant DNA methylation or histone modification is also observed in altering enhancer architecture, which leads to changes in enhancer-promoter contact strength, producing novel explanations for the overexpression of high mobility group AT-hook 2 and gene dysregulation found in mediator complex subunit 12 mutant fibroids. While many molecular mechanisms and epigenomic features have been investigated, the basis for the racial disparity observed among those in the Black population remains unclear.

WIDER IMPLICATIONS

A comprehensive understanding of the exact pathogenesis of uterine leiomyoma is lacking and requires attention as it can provide clues for prevention and viable non-surgical treatment. These findings will widen our knowledge of the role epigenomics plays in the mechanisms related to uterine leiomyoma development and highlight novel approaches for the prevention and identification of epigenome targets for long-term non-invasive treatment options of this significantly common disease.

GnRH Analogues as a Co-Treatment to Therapy in Women of Reproductive Age with Cancer and Fertility Preservation

In this review, we analyzed existing literature regarding the use of Gonadotropin-releasing Hormone (GnRH) analogues (agonists, antagonists) as a co-treatment to chemotherapy and radiotherapy. There is a growing interest in their application as a prophylaxis to gonadotoxicity caused by chemotherapy and/or radiotherapy due to their ovarian suppressive effects, making them a potential option to treat infertility caused by such chemotherapy and/or radiotherapy. They could be used in conjunction with other fertility preservation options to synergistically maximize their effects. GnRH analogues may be a valuable prophylactic agent against chemotherapeutic infertility by inhibiting rapid cellular turnover on growing follicles that contain types of cells unintentionally targeted during anti-cancer treatments. These could create a prepubertal-like effect in adult women, limiting the gonadotoxicity to the lower levels that young girls have. The use of GnRH agonists was found to be effective in hematological and breast cancer treatment whereas for ovarian endometrial and cervical cancers the evidence is still limited. Studies on GnRH antagonists, as well as the combination of both agonists and antagonists, were limited. GnRH antagonists have a similar protective effect to that of agonists as they preserve or at least alleviate the follicle degradation during chemo-radiation treatment. Their use may be preferred in cases where treatment is imminent (as their effects are almost immediate) and whenever the GnRH agonist-induced flare-up effect may be contra-indicated. The combination treatment of agonists and antagonists has primarily been studied in animal models so far, especially rats. Factors that may play a role in determining their efficacy as a chemoprotective agent that limits gonadal damage, include the type and stage of cancer, the use of alkylating agents, age of patient and prior ovarian reserve. The data for the use of GnRH antagonist alone or in combination with GnRH agonist is still very limited. Moreover, studies evaluating the impact of this treatment on the ovarian reserve as measured by Anti-Müllerian Hormone (AMH) levels are still sparse. Further studies with strict criteria regarding ovarian reserve and fertility outcomes are needed to confirm or reject their role as a gonadal protecting agent during chemo-radiation treatments.

Screening and Validation of p38 MAPK Involved in Ovarian Development of Brachymystax lenok

Brachymystax lenok (lenok) is a rare cold-water fish native to China that is of high meat quality. Its wild population has declined sharply in recent years, and therefore, exploring the molecular mechanisms underlying the development and reproduction of lenoks for the purposes of artificial breeding and genetic improvement is necessary. The lenok comparative transcriptome was analyzed by combining single molecule, real-time, and next generation sequencing (NGS) technology. Differentially expressed genes (DEGs) were identified in five tissues (head kidney, spleen, liver, muscle, and gonad) between immature [300 days post-hatching (dph)] and mature [three years post-hatching (ph)] lenoks. In total, 234,124 and 229,008 full-length non-chimeric reads were obtained from the immature and mature sequencing data, respectively. After NGS correction, 61,405 and 59,372 non-redundant transcripts were obtained for the expression level and pathway enrichment analyses, respectively. Compared with the mature group, 719 genes with significantly increased expression and 1,727 genes with significantly decreased expression in all five tissues were found in the immature group. Furthermore, DEGs and pathways involved in the endocrine system and gonadal development were identified, and p38 mitogen-activated protein kinases (MAPKs) were identified as potentially regulating gonadal development in lenok. Inhibiting the activity of p38 MAPKs resulted in abnormal levels of gonadotropin-releasing hormone, follicle-stimulating hormone, and estradiol, and affected follicular development. The full-length transcriptome data obtained in this study may provide a valuable reference for the study of gene function, gene expression, and evolutionary relationships in B. lenok and may illustrate the basic regulatory mechanism of ovarian development in teleosts.

The effects and mechanism of taxanes on chemotherapy-associated ovarian damage: A review of current evidence

Chemotherapy is often a cause of premature ovarian insufficiency and infertility since the ovarian follicles are extremely sensitive to the effects of chemotherapeutic agents. Different chemotherapeutic agents with varying mechanisms of action may damage ovarian function differently. Taxanes are widely used in clinical cancer treatment, but the specific reproductive toxicological information is still controversial. This review described the impact and duration of taxanes on ovarian function in women and analyzed the possible reasons for different conclusions. Furthermore, the toxicity of taxanes on ovarian function and its possible mechanisms were discussed. The potential protective strategies and agents against ovarian damage induced by taxanes are also reviewed.

The effect of pomegranate seed oil on human health, especially epidemiology of polycystic ovary syndrome; a systematic review

Polycystic ovary syndrome is the most common endocrine disorder in women. Today, medicinal plants have been considered by women, especially in the reproductive and pregnancy ages. Multiple drug treatments and the length of the treatment period often lead to incomplete treatment by patients. Therefore, due to the side effects of chemical drugs, this study was conducted to assess investigate the effect of pomegranate seed oil on polycystic ovary syndrome. The prevalence of polycystic ovary syndrome is increasing by 15 to 20% and clinically includes oligomenorrhea or amenorrhea, hirsutism, and often infertility. Databases such as Cochran library, Medline, PubMed, SID, and Science Direct were used to access the related articles. To collect the required information, first, the articles that had one of the keywords of medicinal plants, polycystic ovary syndrome, plant, pomegranate extract, and menstrual irregularities in their text were searched in databases. All studies from 1985 to 2021 are included in the study. Conjugated linolenic acid (CLN) is a group of geometric and positional isomers of linolenic acid in which double bonds are conjugated. CLN has been reported to have a very strong cytotoxic effect on tissue tumor cells in the body, preventing cancer, reducing the accumulation of triacylglycerol in the liver, polycystic ovary syndrome, and LDL cholesterol in the blood. So far, seven CLN isomers have been identified, including ponic acid in pomegranate seed oil. Conjugated linoleic acid (CLA) is a group of situational and geometric isomers of linoleic acid in which double bonds are conjugated. The positive effects of the two main CLA isomers (cis-9, trans-11, and trans-10, cis-12) include inhibiting the growth of cancer, reducing the risk of atherosclerosis, and reducing body fat.

Bone health in transgender people: a narrative review

Bone health in transmen and transwomen is an important issue that needs to be evaluated by clinicians. Prior to gender-affirming hormone treatment (GAHT), transwomen have lower bone mineral density (BMD) and a higher prevalence of osteopenia than cismen probably related to external factors, such as hypovitaminosis D and less physical activities. Gonadotropin-releasing hormone (GnRH) analogues in transgender youth may cause bone loss; however, the addition of GAHT restores or at least improves BMD in both transboys and transgirls. The maintenance or increase in BMD shown in short-term longitudinal studies emphasizes that GAHT does not have a negative effect on BMD in adult transwomen and transmen. Gonadectomy is not a risk factor if GAHT is taken correctly. The prevalence of fractures in the transgender population seems to be the same as in the general population but more studies are required on this aspect. To evaluate the risk of osteoporosis, it is mandatory to define the most appropriate reference group not only taking into consideration the medical aspects but also in respect of the selected gender identity of each person.

Insulin-like peptide 3 (INSL3) in congenital hypogonadotrophic hypogonadism (CHH) in boys with delayed puberty and adult men

BACKGROUND

Delayed puberty in males is almost invariably associated with constitutional delay of growth and puberty (CDGP) or congenital hypogonadotrophic hypogonadism (CHH). Establishing the cause at presentation is challenging, with "red flag" features of CHH commonly overlooked. Thus, several markers have been evaluated in both the basal state or after stimulation e.g. with gonadotrophin releasing hormone agonist (GnRHa).Insulin-like peptide 3 (INSL3) is a constitutive secretory product of Leydig cells and thus a possible candidate marker, but there have been limited data examining its role in distinguishing CDGP from CHH. In this manuscript, we assess INSL3 and inhibin B (INB) in two cohorts: 1. Adolescent boys with delayed puberty due to CDGP or CHH and 2. Adult men, both eugonadal and having CHH.

MATERIALS AND METHODS

Retrospective cohort studies of 60 boys with CDGP or CHH, as well as 44 adult men who were either eugonadal or had CHH, in whom INSL3, INB, testosterone and gonadotrophins were measured. Cohort 1: Boys with delayed puberty aged 13-17 years (51 with CDGP and 9 with CHH) who had GnRHa stimulation (subcutaneous triptorelin 100mcg), previously reported with respect to INB. Cohort 2: Adult cohort of 44 men (22 eugonadal men and 22 men with CHH), previously reported with respect to gonadotrophin responses to kisspeptin-54.

RESULTS

Median INSL3 was higher in boys with CDGP than CHH (0.35 vs 0.15 ng/ml; p=0.0002). Similarly, in adult men, median INSL3 was higher in eugonadal men than CHH (1.08 vs 0.05 ng/ml; p<0.0001). However, INSL3 more accurately differentiated CHH in adult men than in boys with delayed puberty (auROC with 95% CI in adult men: 100%, 100-100%; boys with delayed puberty: 86.7%, 77.7-95.7%).Median INB was higher in boys with CDGP than CHH (182 vs 59 pg/ml; p<0.0001). Likewise, in adult men, median INB was higher in eugonadal men than CHH (170 vs 36.5 pg/ml; p<0.0001). INB performed better than INSL3 in differentiating CHH in boys with delayed puberty (auROC 98.5%, 95.9-100%), than in adult men (auROC 93.9%, 87.2-100%).

CONCLUSION

INSL3 better identifies CHH in adult men, whereas INB better identifies CHH in boys with delayed puberty.

The role of gonadotropin-releasing hormone agonists in female fertility preservation

Advances in anticancer treatments have resulted in increasing survival rates among cancer patients. Accordingly, the quality of life after treatment, particularly the preservation of fertility, has gradually emerged as an essential consideration. Cryopreservation of embryos or unfertilized oocytes has been considered as the standard method of fertility preservation among young women facing gonadotoxic chemotherapy. Other methods, including ovarian suppression and ovarian tissue cryopreservation, have been considered experimental. Recent large-scale randomized controlled trials have demonstrated that temporary ovarian suppression using gonadotropin-releasing hormone agonists (GnRHa) during chemotherapy is beneficial for preventing chemotherapy-induced premature ovarian insufficiency in breast cancer patients. It should also be emphasized that GnRHa use during chemotherapy does not replace established fertility preservation methods. All young women facing gonadotoxic chemotherapy should be counseled about and offered various options for fertility preservation, including both GnRHa use and cryopreservation of embryos, oocytes, and/or ovarian tissue.

Contraceptive efficacy and dose-response effects of the gonadotrophin-releasing hormone (GnRH) agonist deslorelin in Tasmanian devils (Sarcophilus harrisii)

Contraception is increasingly used to manage breeding opportunities in conservation-dependent species. This study aimed to determine the efficacy, duration of effect, optimal dose and potential side effects of Suprelorin contraceptive implants in Tasmanian devils, for use in the conservation breeding program. In our pilot study, Suprelorin was found to effectively suppress oestrous cycles in female devils, yet caused a paradoxical increase in testosterone in males. Therefore, we focussed on females in further trials. Females received one (n=5), two (n=5) or no (n=5) Suprelorin implants, with quarterly gonadotrophin-releasing hormone (GnRH) challenges used to test pituitary responsiveness over two breeding seasons. Both Suprelorin doses suppressed pituitary responsiveness for at least one breeding season, with a reduced effect in the second. There was a dose-response effect on duration rather than magnitude of effect, with high-dose devils remaining suppressed for longer than low-dose animals. There were no apparent negative effects on general health, yet captivity and contraception together may cause weight gain. Suprelorin contraceptive implants are now routinely used in the Save the Tasmanian Devil Program insurance metapopulation to meet the aims of maintaining genetic and behavioural integrity by controlling individual reproductive contributions in group housing situations.

GENETICS IN ENDOCRINOLOGY: Genetic etiologies of central precocious puberty and the role of imprinted genes

Pubertal timing is regulated by the complex interplay of genetic, environmental, nutritional and epigenetic factors. Criteria for determining normal pubertal timing, and thus the definition of precocious puberty, have evolved based on published population studies. The significance of the genetic influence on pubertal timing is supported by familial pubertal timing and twin studies. In contrast to the many monogenic causes associated with hypogonadotropic hypogonadism, only four monogenic causes of central precocious puberty (CPP) have been described. Loss-of-function mutations in Makorin Ring Finger Protein 3(MKRN3), a maternally imprinted gene on chromosome 15 within the Prader-Willi syndrome locus, are the most common identified genetic cause of CPP. More recently, several mutations in a second maternally imprinted gene, Delta-like noncanonical Notch ligand 1 (DLK1), have also been associated with CPP. Polymorphisms in both genes have also been associated with the age of menarche in genome-wide association studies. Mutations in the genes encoding kisspeptin (KISS1) and its receptor (KISS1R), potent activators of GnRH secretion, have also been described in association with CPP, but remain rare monogenic causes. CPP has both short- and long-term health implications for children, highlighting the importance of understanding the mechanisms contributing to early puberty. Additionally, given the role of mutations in the imprinted genes MKRN3 and DLK1 in pubertal timing, other imprinted candidate genes should be considered for a role in puberty initiation.

Population pharmacokinetics of pevonedistat alone or in combination with standard of care in patients with solid tumours or haematological malignancies

AIMS

A population pharmacokinetic (PK) analysis was conducted to quantify the impact of patient-specific and concurrent medication factors on pevonedistat PK.

METHODS

Data were pooled from 6 clinical studies consisting of 335 patients with solid tumours or haematological malignancies administered pevonedistat alone or in combination with azacitidine, docetaxel, carboplatin + paclitaxel, or gemcitabine. Model development and covariate analysis followed standard methods. Parameters and bootstrap 95% confidence intervals were estimated using nonlinear mixed-effects modelling. The final model was evaluated using visual predictive checks and other goodness-of-fit criteria.

RESULTS

A linear 2-compartment model best described pevonedistat PK. The final model included the effect of body surface area (BSA) on clearance (CL and Q) and volume of distribution of pevonedistat, effect of concomitantly administered carboplatin + paclitaxel on CL, and effect of albumin on Q. Race, sex, age, tumour type (haematological vs solid), mild or moderate renal impairment (creatinine clearance ≥30 mL/min), or mild hepatic impairment, had no impact on pevonedistat PK.

CONCLUSIONS

The clinical PK profile of pevonedistat is comparable in patients with solid tumours or haematological malignancies. All PK parameters exhibited ≥20% change over the observed BSA range (1.38-3 m² ) with CL ranging from 75.5 to 208% of the reference value, with simulations supporting BSA-based dosing to minimize interindividual variability in drug exposures. Concurrent administration of carboplatin + paclitaxel decreased pevonedistat CL by approximately 44%, while coadministration with azacitidine, gemcitabine or docetaxel did not alter pevonedistat CL. No other factors were identified as influencing pevonedistat PK.

Phase I trial of TAK-385 in hormone treatment-naïve Japanese patients with nonmetastatic prostate cancer

This open‐label, phase I dose‐finding study evaluated the gonadotropin‐releasing hormone antagonist, TAK‐385, in Japanese patients with nonmetastatic prostate cancer. In a two‐part design, patients received daily oral TAK‐385 at doses of 320 (loading, day 1)/80 (maintenance, day 2 and thereafter), 320/120, 320/160, or 360/120 mg for 28 days in a dose‐escalation phase (part A, n = 13), and at 320/80 or 320/120 mg for up to 96 weeks in a randomized expansion phase (part B, n = 30). Primary endpoint in both parts was safety, including dose‐limiting toxicity in part A. Secondary endpoints included pharmacokinetics, pharmacodynamics, and prostate‐specific antigen concentration. Ten (77%) patients in part A and all patients in part B experienced an adverse event; hot flush (part A, n = 4; part B, n = 15), viral upper respiratory tract infection (part A, n = 1; part B, n = 10), and diarrhea (part B, n = 8) were most frequent. No dose‐limiting toxicities were observed (part A). In 12 evaluable patients (part A), TAK‐385 was rapidly absorbed after a single loading dose; on day 28 (maintenance dose), median steady‐state T_max was ~1‐2 hours and mean t_1/2z was 67‐79 hours. All doses rapidly reduced testosterone concentrations to castration levels within 1 week. Durable reductions in prostate‐specific antigen of >90% from baseline were observed through 96 weeks. TAK‐385 appeared tolerable and resulted in sustained reductions in testosterone to castration levels at all doses. The lowest loading/maintenance dose required for a clinical effect was 320/80 mg.

http://ClinicalTrials.gov: NCT02141659.

Endocrine and Targeted Therapy for Hormone-Receptor-Positive, HER2-Negative Advanced Breast Cancer: Insights to Sequencing Treatment and Overcoming Resistance Based on Clinical Trials

Background: Advanced hormone-receptor positive HER2 negative breast cancer is a common and a very heterogeneous disease. Hormone therapy is the main first line treatment of choice, given alone or in combination with other agents that have shown to improve patient outcomes, Nevertheless, treatment remains generally palliative rather than curative. Sequencing of such treatment remains challenging, especially with resurgence of variable resistance patterns. Multiple attempts have been made to overcome resistance and improve patient survival, yet resistance remains not very well understood and metastatic cancer remains a disease with dismal prognosis.

Methods: In this paper, we searched pubmed database as well as local and international meetings for all studies discussing advanced and metastatic hormone-receptor-positive, her2-negative breast cancer, hormonal treatment, resistance to hormonal treatment, mechanism of resistance, and means to overcome such resistance.

Conclusion: There does not exist an optimal treatment sequence for hormone-receptor-positive, her2-negative advanced breast cancer. However, after review of literature, a reasonable approach may be starting with tamoxifen, aromatase inhibitors, or fulvestrant in absence of visceral crisis, in addition to ensuring adequate ovarian function suppression in pre/peri-menopausal women. Aromatase inhibitors and fulvestrant seem to be superior. Resistance to such agents is increasing, mostly attributed to genetic and molecular changes. Multiple modalities are addressed to overcome such resistance including use of CKD4/6 inhibitors, mTOR inhibitors and PI3K inhibitors in addition to other agents under study, all with promising results. CDK4/6 inhibitors work best when used in frontline setting. Finally, treatment of breast cancer remains a growing field, and more studies are to be awaited.

Uterine fibroids: an update on current and emerging medical treatment options

Uterine fibroids are the most common gynecological disorder, classically requiring surgery when symptomatic. Although attempts at finding a nonsurgical cure date back to centuries, it is only around the middle of the last century that serious attempts at a medical treatment were carried out. Initially, both progestins and estrogen–progestin combinations have been utilized, although proof of their usefulness is lacking. A major step forward was achieved when peptide analogs of the GnRH were introduced, first those with superagonist properties and subsequently those acting as antagonists. Initially, the latter produced side effects preventing their routine utilization; eventually, this problem was overcome following the synthesis of cetrorelix. Because both types of analogs produce hypoestrogenism, their use is limited to a maximum of 6 months and, for this reason, today they are utilized as an adjuvant treatment before surgery with overall good results. Over the last decade, new, nonpeptidic, orally active GnRH-receptor blockers have also been synthesized. One of them, Elagolix, is in the early stages of testing in women with fibroids. Another fundamental development has been the utilization of the so-called selective progesterone receptor modulators, sometimes referred to as “antiprogestins”. The first such compound to be applied to the long-term treatment of fibroids was Mifepristone; today, this compound is mostly used outside of Western Countries, where the substance of choice is Ulipristal acetate. Large clinical trials have proven the effectiveness of Ulipristal in the long-term medical therapy of fibroids, although some caution must be exercised because of the rare occurrence of liver complications. All selective progesterone receptor modulators produce unique endometrial changes that are today considered benign, reversible, and without negative consequences. In conclusion, long-term medical treatment of fibroids seems possible today, especially in premenopausal women.

Evaluation of ovarian and metabolic effects of GnRH modulators in two rat models of polycystic ovary syndrome

Gonadotropin-releasing hormone (GnRH) modulators are widely used in numerous reproductive conditions including infertility. Several clinical studies showed mixed results regarding the efficacy of GnRH modulators in patients with polycystic ovary syndrome (PCOS). Along with this, few preclinical studies focus on the effect of GnRH modulators in PCOS-induced animals. Therefore, the present study was designed to study the effect of leuprolide and cetrorelix on hormonal, metabolic, and menstrual dysfunction PCOS rats. Prepubertal female rats were divided into four groups: Group I received a normal pellet diet and Groups II, III, and IV received 40% high-fat diet for 105 days. Similarly, adult female rats were divided into four groups: Group I received 1% carboxymethylcellulose (CMC) and Groups II, III, and IV received letrozole (1 mg/kg, per oral [p.o.] in 1% CMC) for 21 days. Thereafter, leuprolide (2.5 µg/rat, s.c.) and cetrorelix (10 µg/kg, subcutaneous [s.c.]) treatment were given to Group III and Group IV animals, respectively, for 21 days. Oral glucose tolerance test, lipid profile, fasting glucose, insulin, estrus cycle, hormonal profile, ovary weight, ovarian histopathological changes, and LHR and FSHR expressions were measured. Treatment with leuprolide and cetrorelix did not improve glucose intolerance, insulin level, insulin sensitivity indices, sex hormone levels, lipid profile, and estrus cycle. Only testosterone level, total cholesterol level, and follicular development were improved. Therefore, it was concluded that both leuprolide and cetrorelix showed improvement in follicular development, which could be helpful for improving fertility in PCOS.

Triptorelin: A Review of its Use as an Adjuvant Anticancer Therapy in Early Breast Cancer

A 1-month formulation of the gonadotrophin-releasing hormone agonist (GnRHa) triptorelin (Decapeptyl^®) has been approved in the EU as an adjuvant treatment in combination with tamoxifen or an aromatase inhibitor (AI), of endocrine-responsive, early-stage breast cancer in women at high risk of recurrence who are confirmed as premenopausal after completion of chemotherapy. This indication reflects the results of the 5-year SOFT and TEXT studies, especially SOFT, in which ovarian function suppression (OFS; mainly achieved with triptorelin) added to tamoxifen provided a significant benefit in the overall study population of premenopausal patients only after adjusting for prognostic factors. It emerged that adding OFS to tamoxifen produced more pronounced benefits in terms of disease control and, furthermore, increased overall survival in the cohort of higher-risk patients who had previously received chemotherapy. Also, compared with tamoxifen alone, the combination of OFS plus exemestane produced more pronounced benefits in terms of disease control than OFS plus tamoxifen. OFS induces premature menopause; when combined with either tamoxifen or exemestane, it increased the endocrine symptom burden. Nonetheless, the two combinations had distinct tolerability profiles (e.g. vasomotor symptoms and thromboembolic events were more frequent with OFS plus tamoxifen, whereas musculoskeletal symptoms, decreased libido, osteoporosis and fractures were more frequent with OFS plus exemestane). Thus, the combinations of OFS (with triptorelin) plus either tamoxifen or an AI are valid options for the adjuvant treatment of endocrine-responsive, early-stage breast cancer in women at sufficiently high risk of relapse to warrant receiving chemotherapy and who remain premenopausal thereafter. Individualized weighing of the potential benefits and adverse effects of treatment is required.

A role for selective contraception of individuals in conservation

Contraception has an established role in managing overabundant populations and preventing undesirable breeding in zoos. We propose that it can also be used strategically and selectively in conservation to increase the genetic and behavioral quality of the animals. In captive breeding programs, it is becoming increasingly important to maximize the retention of genetic diversity by managing the reproductive contribution of each individual and preventing genetically suboptimal breeding through the use of selective contraception. Reproductive suppression of selected individuals in conservation programs has further benefits of allowing animals to be housed as a group in extensive enclosures without interfering with breeding recommendations, which reduces adaptation to captivity and facilitates the expression of wild behaviors and social structures. Before selective contraception can be incorporated into a breeding program, the most suitable method of fertility control must be selected, and this can be influenced by factors such as species life history, age, ease of treatment, potential for reversibility, and desired management outcome for the individual or population. Contraception should then be implemented in the population following a step-by-step process. In this way, it can provide crucial, flexible control over breeding to promote the physical and genetic health and sustainability of a conservation dependent species held in captivity. For Tasmanian devils (Sarcophilus harrisii), black-flanked rock wallabies (Petrogale lateralis), and burrowing bettongs (Bettongia lesueur), contraception can benefit their conservation by maximizing genetic diversity and behavioral integrity in the captive breeding program, or, in the case of the wallabies and bettongs, by reducing populations to a sustainable size when they become locally overabundant. In these examples, contraceptive duration relative to reproductive life, reversibility, and predictability of the contraceptive agent being used are important to ensure the potential for individuals to reproduce following cessation of contraception, as exemplified by the wallabies when their population crashed and needed females to resume breeding.

Gonadotropin-releasing hormone agonists for ovarian protection during cancer chemotherapy: systematic review and meta-analysis

OBJECTIVE

To evaluate the effectiveness of gonadotropin-releasing hormone agonist (GnRHa) administration before and/or during cancer chemotherapy for the protection of ovarian reserve in premenopausal women without prior diagnosis of infertility.

METHODS

This was a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing administration of GnRHa before and/or during chemotherapy vs chemotherapy alone. Eligible participants were premenopausal women at any stage of cancer, without previous diagnosis of infertility. An electronic database search in MEDLINE, CENTRAL, LILACS and ClinicalTrials.gov was performed. After selecting eligible studies, the relative risk (RR) was assessed for primary ovarian insufficiency (POI)/amenorrhea and for spontaneous pregnancy after completion of treatment.

RESULTS

Thirteen RCTs comparing concurrent use of GnRHa and chemotherapy (609 participants) with chemotherapy alone (599 participants) were eligible for meta-analysis. All trials were open-label and patients had been treated for breast cancer (n = 1099) or lymphoma (n = 109). GnRHa had a significant benefit on the risk of POI/amenorrhea (RR, 0.60; 95% CI, 0.45-0.79), which persisted in subgroup analysis for breast cancer (RR, 0.57; 95% CI, 0.43-0.77) but not for lymphoma patients (RR, 0.70; 95% CI, 0.20-2.47). The rate of spontaneous pregnancy after completion of treatment was higher in women receiving GnRHa plus chemotherapy compared with those receiving chemotherapy alone (RR, 1.43; 95% CI, 1.01-2.02). Overall, the quality of evidence was low due to the unclear risk of bias, short follow-up and lack of objective assessment of ovarian function and reserve.

CONCLUSIONS

Evidence, albeit of low quality, supports the use of GnRHa before and/or during chemotherapy to reduce the risk of POI and increase the probability of spontaneous pregnancy in the short term. Further high quality RCTs with more accurate assessment of ovarian reserve are needed to support definitive recommendations for clinical practice. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Fertility preservation in reproductive-age women facing gonadotoxic treatments

BACKGROUND

Advancements in the treatments for cancer and autoimmune and other hematologic conditions continue to improve survival and cure rates. Despite those changes, various gonadotoxic agents and other treatments can still compromise the future fertility of many women. Progress in medical and surgical reproductive technologies has helped to offset the reproductive consequences of the use of gonadotoxic therapies, and allows for future fertility and normal pregnancy.

METHODS

A review of the literature was performed to outline the pathophysiology of gonadotoxicity from various treatments. The success of fertility preservation, fertility sparing, and cryopreservation options are reviewed. Barriers and facilitators to referral and oncofertility treatment in Canada are also outlined.

RESULTS

According to the quality of the evidence, recommendations are made for fertility assessment, patient referral, cryopreservation, and other assisted reproductive technologies.

CONCLUSIONS

To ensure ongoing fertility in women undergoing gonadotoxic treatments, assisted reproductive technologies can be combined with a multidisciplinary approach to patient assessment and referral.

Targeting the relaxin hormonal pathway in prostate cancer

Targeting the androgen signalling pathway has long been the hallmark of anti-hormonal therapy for prostate cancer. However, development of androgen-independent prostate cancer is an inevitable outcome to therapies targeting this pathway, in part, owing to the shift from cancer dependence on androgen signalling for growth in favor of augmentation of other cellular pathways that provide proliferation-, survival- and angiogenesis-promoting signals. This review focuses on the role of the hormone relaxin in the development and progression of prostate cancer, prior to and after the onset of androgen independence, as well as its role in cancers of other reproductive tissues. As the body of literature expands, examining relaxin expression in cancerous tissues and its role in a growing number of in vitro and in vivo cancer models, our understanding of the important involvement of this hormone in cancer biology is becoming clearer. Specifically, the pleiotropic functions of relaxin affecting cell growth, angiogenesis, blood flow, cell migration and extracellular matrix remodeling are examined in the context of cancer progression. The interactions and intercepts of the intracellular signalling pathways of relaxin with the androgen pathway are explored in the context of progression of castration-resistant and androgen-independent prostate cancers. We provide an overview of current anti-hormonal therapeutic treatment options for prostate cancer and delve into therapeutic approaches and development of agents aimed at specifically antagonizing relaxin signalling to curb tumor growth. We also discuss the rationale and challenges utilizing such agents as novel anti-hormonals in the clinic, and their potential to supplement current therapeutic modalities.

Actions of gonadotropin-releasing hormone analogues in pituitary gonadotrophs and their modulation by ovarian steroids

Recently, GnRH antagonists (GnRHant) like cetrorelix and ganirelix have been introduced in protocols of controlled ovarian hyperstimulation for assisted reproductive techniques to prevent premature luteinizing hormone (LH) surges. Here we tested, whether the actions of cetrorelix and the GnRH agonist (GnRHag) triptorelin in gonadotrophs are dependent on the steroid milieu. Furthermore, we characterized the actions of cetrorelix and triptorelin on LH secretion and the total LH pool. Female rat pituitary cells were treated either with 0.1 nM triptorelin for 1, 2, 4 and 6 days or for 1, 3, 5 and 6 h or with 1, 10 or 100 nM cetrorelix for 1, 2, 3 and 5 h or for 10 min. Cells were stimulated for 3h with different concentrations of GnRH (10 pM-1 microM). For analysis of the total LH pool, which is composed of stored and released LH, cells were lysed with 0.1% Triton X-100 at -80 degrees C overnight. To test, whether the steroid milieu affects the actions of cetrorelix and triptorelin, cells were incubated for 52 h with 1 nM estradiol (E) alone or with combinations of 100 nM progesterone (P) for 4 or 52 h, respectively. Cells were then treated with 0.1 nM triptorelin for 9 h or 1 nM cetrorelix for 3 h and stimulated for 3 h with different concentrations of GnRH (10 pM-1 microM). The suppressive effect of triptorelin on LH secretion was fully accomplished after 3 h of treatment, for cetrorelix only 10 min were sufficient. The concentration of cetrorelix must be at least equimolar to GnRH to block LH secretion. Cetrorelix shifted the EC50s of the GnRH dose-response curve to the right. Triptorelin suppressed total LH significantly (from 137 to 36 ng/ml) after 1 h in a time-dependent manner. In contrast, only high concentrations of cetrorelix increased total LH. In steroid treated cells the suppressive effects of triptorelin were more distinct. One nanomolar cetrorelix suppressed GnRH-stimulated LH secretion of cells not treated with steroids from 10.1 to 3.5 ng/ml. In cells, additionally treated with estradiol alone or estradiol and short-term progesterone, LH levels were higher (from 3.5 to 5.4 or 4.5 ng/ml, respectively). In cells co-treated with estradiol and progesterone for 52 h LH secretion was only suppressed from 10.1 to 9.5 ng/ml. Steroid treatments diminished the suppressive effect of cetrorelix on LH secretion. In conclusion, the depletion of the total LH pool contributes to the desensitizing effect of triptorelin. The actions of cetrorelix and triptorelin are dependent on the steroid milieu.

Regulation of GnRH I receptor gene expression by the GnRH agonist triptorelin, estradiol, and progesterone in the gonadotroph-derived cell line alphaT3-1

The secretion of luteinizing hormone (LH) and the GnRH receptor (GnRH-R) concentration are modulated by ovarian steroids and GnRH. To elucidate whether this regulation is due to alterations at the transcriptional level, we examined the GnRH I-R mRNA expression in the gonadotroph-derived cell line alphaT3-1 treated with different estradiol and progesterone paradigms and the GnRH I agonist triptorelin. alphaT3-1 cells were treated with different steroid paradigms: 1 nM estradiol or 100 nM progesterone for 48 h alone or in combination. Cells were exposed to 10 nM or 100 pM triptorelin for 30 min, 3 h, 9 h, or, in pulsatile way, with a 5-min pulse per hour. The GnRH I-R mRNA was determined by Northern blot analysis. GnRH I-R mRNA from cells treated with continuous triptorelin decreased in a time- and concentration-dependent manner. Pulsatile triptorelin increased GnRH I-R gene expression. Progesterone alone further enhanced this effect, whereas estradiol and its combination with progesterone diminished it. Continuous combined treatment with estradiol and progesterone lead to a significant decrease of GnRH I-R mRNA by 30% and by 35% for estradiol alone. The addition of 10 nM triptorelin for 30 min or 3 h could not influence that steroid effect. In conclusion, estradiol and progesterone exclusively decreased GnRH I-R mRNA in alphaT3-1 cells no matter whether they are treated additionally with the GnRH I agonist triptorelin. The enhanced sensitivity of gonadotrophs and GnRH I-R upregulation by estradiol is not due to increased GnRH I gene expression because GnRH I-R mRNA is downregulated by estradiol and progesterone. Other pathways of the GnRH I-R signal transduction might be involved.

Depot GnRH agonist versus the single dose GnRH antagonist regimen (cetrorelix, 3 mg) in patients undergoing assisted reproduction treatment

The objective of this study was to compare, in a centre with previous experience of gonadotrophin-releasing hormone (GnRH) antagonist use, single administration of a GnRH antagonist [cetrorelix (Cetrotide) 3 mg] with a single administration of a GnRH agonist [Decapeptyl Retard 3.75 mg] in patients undergoing assisted reproduction treatment (n = 307 and 364 respectively). GnRH agonist was administered on the first day of menses, while cetrorelix was administered when the largest follicle reached 14 mm. Ovarian stimulation was performed with recombinant human FSH (r-hFSH; 150-225 IU/day). Human chorionic gonadotrophin (HCG, 10,000 IU) was administered when at least two follicles reached a mean diameter > or =18 mm. Over 90% of patients in both groups reached the criteria for HCG administration and underwent oocyte retrieval and embryo transfer. Duration of FSH therapy (9.95 versus 11.25 days) and cumulative dose of r-hFSH (1604 versus 1980 IU) were significantly reduced (P < 0.01) in the cetrorelix 3 mg group. The number of oocytes retrieved was lower (8.5 versus 11.2; P < 0.01) with cetrorelix, but the number of embryos replaced was similar (2.2 versus 2.3; NS). The pregnancy rates per oocyte retrieval were the same, 24.5%, in the antagonist and agonist groups. This study indicates that although fewer oocytes are recovered, similar pregnancy rates can be achieved with a GnRH antagonist compared with a GnRH agonist. Additionally, a single dose of 3 mg cetrorelix was administered in 84% of patients, thus being simpler and more convenient for patients. Cetrorelix 3 mg may thus be proposed as a first choice for preventing both a premature LH surge and detrimental rises in LH during ovarian stimulation prior to assisted reproduction treatment.