Clinical utility of progesterone receptor modulators and their effect on the endometrium

Progesterone signaling in uterine leiomyoma biology: Implications for potential targeted therapy

Uterine leiomyomas (ULs) are the most common benign smooth muscle cell steroid-dependent tumors that occur in women of reproductive age. Progesterone (P4) is a major hormone that promotes the ULs development and growth. P4 action in ULs is mediated mainly by its nuclear progesterone receptors (PGRs), although rapid non-genomic responses have also been observed. Data on the membrane progesterone receptors (mPRs) regulated signaling pathways in ULs in the available literature is still very limited. One of the essential characteristics of ULs is the excessive production of extracellular matrix (ECM). P4 has been shown to stimulate ECM production and collagen synthesis in ULs. Recent research demonstrated that, despite their benign nature, ULs may present with abnormal vasculature. P4 has been shown to regulate angiogenesis in ULs through the upregulation of vascular endothelial growth factor (VEGF) and by controlling the secretion of permeability factors. This review summarizes the key findings regarding the role of PGRs and mPRs in ULs, especially highlighting the potential ECM and angiogenesis modulation by P4. An increased understanding of this mechanistic role of nuclear and specifically mPRs in the biology of P4-modulated ECM and angiogenesis in the growth of ULs could turn out to be fundamental for developing effective targeted therapies for ULs.

Current and Emerging Treatment Options for Uterine Fibroids

Uterine fibroids are the most common benign neoplasm of the female reproductive tract in reproductive age women. Their prevalence is age dependent and can be detected in up to 80% of women by the age of 50 years. Patients affected by uterine fibroids may experience a significant physical, emotional, social, and financial toll as well as losses in their quality of life. Unfortunately, curative hysterectomy abolishes future pregnancy potential, while uterine-sparing surgical and radiologic alternatives are variously associated with reduced long-term reproductive function and/or high tumor recurrence rates. Recently, pharmacological treatment against uterine fibroids have been widely considered by patients to limit uterine fibroid-associated symptoms such as heavy menstrual bleeding. This hormonal therapy seemed effective through blocking the stimulatory effects of gonadal steroid hormones on uterine fibroid growth. However, they are contraindicated in women actively pursuing pregnancy and otherwise effective only during use, which is limited because of long-term safety and other concerns. Accordingly, there is an urgent unmet need for safe, durable, and fertility-compatible non-surgical treatment options for uterine fibroids. In this review article, we cover the current pharmacological treatments for uterine fibroids including their comparable efficacy and side effects as well as emerging safe natural compounds with promising anti-uterine fibroid effects.

Novel microarchitecture of human endometrial glands: implications in endometrial regeneration and pathologies

BACKGROUND

Human endometrium remains a poorly understood tissue of the female reproductive tract. The superficial endometrial functionalis, the site of embryo implantation, is repeatedly shed with menstruation, and the stem cell-rich deeper basalis is postulated to be responsible for the regeneration of the functionalis. Two recent manuscripts have demonstrated the 3D architecture of endometrial glands. These manuscripts have challenged and replaced the prevailing concept that these glands end in blind pouches in the basalis layer that contain stem cells in crypts, as in the intestinal mucosa, providing a new paradigm for endometrial glandular anatomy. This necessitates re-evaluation of the available evidence on human endometrial regeneration in both health and disease in the context of this previously unknown endometrial glandular arrangement.

OBJECTIVE AND RATIONALE

The aim of this review is to determine if the recently discovered glandular arrangement provides plausible explanations for previously unanswered questions related to human endometrial biology. Specifically, it will focus on re-appraising the theories related to endometrial regeneration, location of stem/progenitor cells and endometrial pathologies in the context of this recently unravelled endometrial glandular organization.

SEARCH METHODS

An extensive literature search was conducted from inception to April 2021 using multiple databases, including PubMed/Web of Science/EMBASE/Scopus, to select studies using keywords applied to endometrial glandular anatomy and regeneration, and the references included in selected publications were also screened. All relevant publications were included.

OUTCOMES

The human endometrial glands have a unique and complex architecture; branched basalis glands proceed in a horizontal course adjacent to the myometrium, as opposed to the non-branching, vertically coiled functionalis glands, which run parallel to each other as is observed in intestinal crypts. This complex network of mycelium-like, interconnected basalis glands is demonstrated to contain endometrial epithelial stem cells giving rise to single, non-branching functionalis glands. Several previous studies that have tried to confirm the existence of epithelial stem cells have used methodologies that prevent sampling of the stem cell-rich basalis. More recent findings have provided insight into the efficient regeneration of the human endometrium, which is preferentially evolved in humans and menstruating upper-order primates.

WIDER IMPLICATIONS

The unique physiological organization of the human endometrial glandular element, its relevance to stem cell activity and scarless endometrial regeneration will inform reproductive biologists and clinicians to direct their future research to determine disease-specific alterations in glandular anatomy in a variety of endometrial pathological conditions.

Local Transdermal Delivery of Telapristone Acetate Through Breast Skin, Compared With Oral Treatment: A Randomized Double-Blind, Placebo-Controlled Phase II Trial

Oral breast cancer prevention medications entail systemic exposure, limiting acceptance by high-risk women. Delivery through the breast skin, although an attractive alternative, requires demonstration of drug distribution throughout the breast. We conducted a randomized double-blind, placebo-controlled phase II clinical trial comparing telapristone acetate, a progesterone receptor antagonist, administered orally (12 mg/day) or transdermally (12 mg/breast) for 4 ± 1 weeks to women planning mastectomy. Plasma and tissue concentrations, measured at five locations in the mastectomy specimen using liquid chromatography tandem mass spectrometry were compared. In 60 evaluable subjects, median drug concentration (ng/g tissue) was 103 (interquartile range (IQR): 46.3-336) in the oral vs. 2.82 (IQR: 1.4-5.5) in the transdermal group. Despite poor dermal permeation, within-breast drug distribution pattern was identical in both groups (R2  = 0.88, P = 0.006), demonstrating that transdermally and orally delivered drug is distributed similarly through the breast, and is strongly influenced by tissue adiposity (P < 0.0001). Other skin-penetrant drugs should be tested for breast cancer prevention.

Vitamin D: Mechanism of Action and Biological Effects in Uterine Fibroids

Uterine fibroids (UFs) are the most common benign gynecological tumors. It was estimated that fifty percent of women presenting with UFs has symptomatology that negatively influences their quality of life. Pharmacological and/or surgical treatments are frequently required, depending on the woman's desire to preserve fertility, with a high impact on healthcare costs. Generally, the use of currently available pharmacological treatments may lead to side effects. Therefore, there is a growing interest in a natural and safe approach for UFs. In recent years, epidemiological studies reported a vitamin D deficiency in patients with UFs raised interest in the potential biological effects of vitamin D supplementation. In vitro studies proved vitamin D efficacy in inhibiting UFs growth by targeting pathways involved in the regulation of various biological processes, including proliferation, extracellular matrix (ECM) remodeling, DNA repair, signaling and apoptosis. However, clinical studies supported only in part the beneficial effects of vitamin D supplementation in reducing UFs growth and tumor volume. Randomized controlled trials and large population studies are mandatory as the potential clinical benefits are likely to be substantial.

The Evolving Role of Natural Compounds in the Medical Treatment of Uterine Fibroids

Uterine fibroids (UFs) remain a significant health issue for many women, with a disproportionate impact on women of color, likely due to both genetic and environmental factors. The prevalence of UFs is estimated to be approximately 70% depending on population. UF-derived clinical symptoms include pelvic pain, excessive uterine bleeding, gastrointestinal and voiding problems, as well as impaired fertility. Nowadays numerous methods of UF treatment are available-from conservative treatment to invasive surgeries. Selecting an appropriate treatment option should be individualized and adjusted to the patient's expectations as much as possible. So far, the mainstay of treatment is surgery, but their negative impact of future fertility is clear. On the other hand, emerging new pharmaceutical options have significant adverse effects like liver function impairment, hot flashes, bone density loss, endometrial changes, and inability to attempt conception during treatment. Several natural compounds are found to help treat UFs and relieve their symptoms. In this review we summarize all the current available data about natural compounds that may be beneficial for patients with UFs, especially those who want to preserve their future fertility or have treatment while actively pursuing conception. Vitamin D, epigallocatechin gallate, berberine, curcumin, and others are being used as alternative UF treatments. Moreover, we propose the concept of using combined therapies of natural compounds on their own or combined with hormonal agents to manage UFs. There is a strong need for more human clinical trials involving these compounds before promoting widespread usage.

Celecoxib, a selective COX-2 inhibitor, markedly reduced the severity of tamoxifen-induced adenomyosis in a murine model

The aim of the present study was to evaluate the effects of the selective cyclooxygenase (COX)-2 inhibitor celecoxib on the development of uterine adenomyosis in mice. ICR neonatal mice were first exposed to tamoxifen to establish a mouse model of adenomyosis. Following 60 days of celecoxib treatment, pathological formation of adenomyosis lesions and the depth of myometrial infiltration were evaluated using hematoxylin and eosin staining. To examine thermal pain modulation in mice, a hotplate test was conducted every 15 days from postnatal day 30 onwards. Immunohistochemistry was performed to assess the expression of aromatase P450, N-cadherin, E-cadherin, COX-2 and cluster of differentiation 31, whereas the levels of estrogen were analyzed in uterine tissue homogenates using ELISA. Masson trichrome staining was performed to assess the extent of fibrosis in the uterus. Celecoxib treatment significantly inhibited the depth of infiltration into the myometrium, resulting in significantly reduced disease severity. Treatment with high doses of celecoxib significantly prolonged thermal response latency. Following celecoxib treatment, the expression of E-cadherin was significantly increased whereas the expression of N-cadherin was significantly decreased. Concomitantly, the extent of fibrosis was also reduced following celecoxib treatment. Uterine tissue homogenates isolated from mice treated with both high and low doses of celecoxib exhibited lower concentrations of estrogen and decreased expression of aromatase P450. These observations suggest that celecoxib reduces adenomyosis severity by suppressing estrogen production in the uterus, reversing epithelial-mesenchymal transition and relieving fibrosis. Taken together, the results of the present study support the potential use of celecoxib, a selective COX-2 inhibitor, for the treatment of adenomyosis.

Perfluorooctanoic acid alters progesterone activity in human endometrial cells and induces reproductive alterations in young women

Female fecundity is finely regulated by hormonal signaling, representing a potential target for endocrine-disrupting chemicals. Among the chemicals of most concern are the perfluoroalkyl substances (PFAS), widely used in consumer goods, that are associated with adverse effects on reproductive health. In this context, the endometrium clearly represents an important fertility determining factor. The aim of this study was to investigate PFAS interference on hormonal endometrial regulation. This study was performed within a screening protocol to evaluate reproductive health in high schools. We studied a cohort of 146 exposed females aged 18-21 from the Veneto region in Italy, one of the four areas worldwide heavily polluted with PFAS, and 1080 non-exposed controls. In experiments on Ishikawa cells included UV-Vis spectroscopy, microarray analysis and qPCR. We report a significant dysregulation of the genetic cascade leading to embryo implantation and endometrial receptivity. The most differentially-expressed genes upon PFOA coincubation were ITGB8, KLF5, WNT11, SULT1E1, ALPPL2 and G0S2 (all p < 0.01). By qPCR, we confirmed an antagonistic effect of PFOA on all these genes, which was reversed at higher progesterone levels. Molecular interference of PFOA on progesterone was confirmed by an increase in the intensity of absorption spectra at 250 nm in a dose-dependent manner, but not in the presence of β-estradiol. Age at menarche (+164 days, p = 0.006) and the frequency of girls with irregular periods (29.5% vs 21.5%, p = 0.022) were significantly higher in the exposed group. Our results are indicative of endocrine-disrupting activity of PFAS on progesterone-mediated endometrial function.

Ulipristal acetate for Japanese women with symptomatic uterine fibroids: A double-blind, randomized, phase II dose-finding study

PURPOSE

A multicenter, randomized, double-blind, placebo-controlled trial was conducted to evaluate the efficacy, safety, and appropriate dose of ulipristal acetate (UPA) in Japanese women with symptomatic uterine fibroids (UFs).

METHODS

A total of 121 premenopausal women with UFs were enrolled to receive either placebo, UPA-2.5 mg, UPA-5 mg, UPA-10 mg, or leuprorelin acetate (LEU), a reference drug, for 12 weeks. The primary end point was the rate of patients having achieved amenorrhea for 35 days at Week 12.

RESULTS

The rates for amenorrhea were 4.5%, 60.0%, 72.7%, 88.0%, and 76.2% in the placebo, UPA-2.5 mg, UPA-5 mg, UPA-10 mg, and LEU groups, respectively. The median times to amenorrhea were 20.0, 5.0, 5.0, and 23.0 days for treatment with UPA-2.5 mg, UPA-5 mg, UPA-10 mg, and LEU, respectively. A significant dose-response of UPA for the rate of amenorrhea was observed. The overall incidence rates of adverse events were 45.8% in the placebo group, 56.5%-80.0% in the UPA groups, and 100.0% in the LEU group. There were no notable safety issues with UPA.

CONCLUSIONS

Ulipristal acetate was effective and well tolerated in Japanese women with UFs. The recommended dose of UPA is considered to be 10 mg.

Differences in fibroid vascularity after three months of pre-treatment with leuprolide acetate or ulipristal acetate: A pilot study

OBJECTIVES

To investigate differences in volume and fibroid vascularity expressed in vascular index after three months of (pre-)treatment with leuprolide acetate (LPA) or ulipristal acetate (UPA).

STUDY DESIGN

Prospective pilot study of 23 premenopausal women with uterine fibroids. Patients who started with LPA or UPA and had at least one fibroid with a size between 3 and 12 cm, were included consecutively. Per patient one fibroid was evaluated. The ultrasound was performed at baseline and after three months using LPA or UPA using a standardized protocol. 3D scans were evaluated using VOCAL software to calculate outcomes of volume, vascular index (VI) without shell ("shell off") and of the inner shell.

RESULTS

Four patients in the LPA group were additionally excluded from analyses due to insufficient quality of 3D scans. In the ten remaining patients (pre-)treated with LPA both volume and vascular indices of the fibroid reduced significantly after three months from a median of 224.3 cm³ (IQR 338.0) to 124.8 cm³ (IQR 186.1) (p = 0,05); median VI fibroid (shell off) reduced from 4.30 (IQR 4.72) to 0.93 (IQR 1.54) (p = 0,05); and VI inner capsule from 6.34 (IQR 7.51) to 1.28 (IQR 2.13) (p = 0,05). After UPA (n = 9) changes in fibroid volume and vascular indices did not reach statistical significance. Volume reduced from 248.5 cm³ (IQR 271.9) to 140.7 cm³ (IQR 209.4) (p > 0,05); median VI fibroid (shell off) from 2.97 (IQR 3.81) to 2.90 (IQR 4.82) (p > 0,05); and VI inner capsule from 2.56 (IQR 7.48) to 2.89 (IQR 4.83) (p > 0,05). A strong positive correlation was found between the VI of the fibroid (shell off) at baseline with the volume change after three months of LPA use (LPA r = 0.636, p = 0.048, 95% CI = -0.03 - 1.00).

CONCLUSION

In this pilot study we observed a consistent and statistically significant decrease in VI and fibroid volume after three months of LPA treatment in patients with uterine fibroids. The decrease in fibroid volume and VI was less consistent after UPA use. The strong correlation between the VI at baseline and volume reduction, may in theory be used to predict the volume reduction after LPA.

Myometrial progesterone hyper-responsiveness associated with increased risk of human uterine fibroids

BACKGROUND

Uterine Fibroids (UFs) growth is ovarian steroid-dependent. Previous studies have shown that estrogen and progesterone play an important role in UF development. However, the mechanism underlying progesterone induced UF pathogenesis is largely unknown. In this study, we determined the expression of progesterone receptor and compared the expression level of progesterone-regulated genes (PRGs) in human myometrial cells from normal uteri (MyoN) versus uteri with UFs (MyoF) in response to progesterone.

METHODS

Primary human myometrial cells were isolated from premenopausal patients with structurally normal uteri (PrMyoN). Primary human myometrial cells were also isolated from uterus with UFs (PrMyoF). Isolated tissues were excised at least 2 cm from the closest UFs lesion(s). Progesterone receptor (PR) expression was assessed using Western blot (WB). Expression levels of 15 PRGs were measured by qRT-PCR in PrMyoN and PrMyoF cells in the presence or absence of progesterone.

RESULTS

WB analysis revealed higher expression levels of PR in PrMyoF cells as compared to PrMyoN cells. Furthermore, we compared the expression patterns of 15 UF-related PRGs in PrMyoN and PrMyoF primary cells in response to progesterone hormone treatment. Our studies demonstrated that five PRGs including Bcl2, FOXO1A, SCGB2A2, CYP26a1 and MMP11 exhibited significant progesterone-hyper-responsiveness in human PrMyoF cells as compared to PrMyoN cells (P < 0.05). Another seven PRGs, including CIDEC, CANP6, ADHL5, ALDHA1, MT1E, KIK6, HHI showed gain in repression in response to progesterone treatment (P > 0.05). Importantly, these genes play crucial roles in cell proliferation, apoptosis, cell cycle, tissue remodeling and tumorigenesis in the development of UFs.

CONCLUSION

These data support the idea that progesterone acts as contributing mechanism in the origin of UFs. Identification and analysis of these PRGs will help to further understand the role of progesterone in UF development.

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.

Fibroid management in premenopausal women

Uterine fibroids are the most common tumors affecting premenopausal women, responsible for bleeding, pain, and reduced quality of life. When symptomatic, their management mainly involves surgery, which is all too often radical (hysterectomy). While surgical options sparing the uterus (hysteroscopic and laparoscopic myomectomy) and other non-surgical approaches do indeed exist, drug-based therapies are associated with lower costs and morbidity rates. Since progesterone is required for fibroid growth, gonadotropin agonists have been used to control bleeding and decrease fibroid volume, but they only represent a temporary remedy due to adverse events. Ulipristal acetate (UPA), a selective progesterone receptor modulator, is indicated for fibroid management. It is safe, provides fast control of bleeding, and causes sustained fibroid volume reduction in the vast majority of cases (80%). Indeed, UPA-treated fibroids shrink by a combination of inhibition of cell proliferation, stimulation of cell death, and fibrosis resorption. In the case of symptom recurrence, repeated intermittent 3-month courses of daily UPA considerably maximize the impact of treatment, sometimes resulting in complete disappearance of treated fibroids. Despite the therapeutic dose of UPA being very well tolerated, patients with liver anomalies or disorders should be excluded at screening according to European Medicines Agency-Pharmacovigilance Risk Assessment Committee (PRAC) recommendations. We therefore propose new algorithms for fibroid management in premenopausal women with symptomatic fibroids, depending on their localization, the patient's wishes, and clinical response, while monitoring liver enzymes and bilirubin, as recommended by the PRAC, in order to minimize the risks of possible liver toxicity.

A Multicenter Study Evaluating the Effect of Ulipristal Acetate during Myomectomy

STUDY OBJECTIVE

To compare surgical experience at myomectomy between patients with myomas pretreated with ulipristal acetate versus no pretreatment.

DESIGN

A prospective, observational, multicenter study of myomectomy procedures by any route (hysteroscopic, laparoscopic, or laparotomy) (Canadian Task Force classification II-2).

SETTING

Five university-affiliated hospitals including tertiary care and community sites.

PATIENTS

Any patient who underwent hysteroscopic, laparotomic, or laparoscopic myomectomy regardless of medical pretreatment.

INTERVENTIONS

Surgeons completed a Web-based questionnaire after each myomectomy procedure. Surgeons evaluated visualization, the myoma-myometrium relationship, extrusion, fluid deficit, blood loss, and overall ease of hysteroscopic myomectomies. For laparotomic/laparoscopic myomectomies, plane delineation, myoma separation, blood loss, and overall ease were assessed. The total surgical experience score was calculated by summing the values for each subscale.

MEASUREMENTS AND MAIN RESULTS

A total of 309 myomectomies were evaluated by 52 surgeons (response rate = 83%) at 5 institutions. Of 140 hysteroscopic myomectomies, 84 (60%) were performed without pretreatment, 29 (21%) after ulipristal acetate pretreatment, and 27 (19%) after pretreatment with gonadotropin-releasing hormone agonist/other. Of 169 laparotomic/laparoscopic myomectomies, 104 (62%) were performed without pretreatment, 46 (27%) after ulipristal acetate, and 19 (11%) after gonadotropin-releasing hormone agonist/other. The mean surgical experience score (±standard deviation) was comparable between the no pretreatment and ulipristal acetate groups for hysteroscopic myomectomies (13.8 ± 2.2 vs 13.3 ± 2.2, p = .35) and laparotomic/laparoscopic myomectomies (12.9 ± 4.1 vs 12.1 ± 4.2, p = .30). Compared with no pretreatment, more laparotomic/laparoscopic myomectomies after ulipristal acetate pretreatment were associated with difficult delineation of surgical planes (22 [47.8%] vs 23 [22.1%], p = .002) and difficult myoma separation (20 [43.5%] vs 21 [20.2%], p = .003). More myomas were described as soft with ulipristal acetate pretreatment (14 [30.4%] vs 17 [16.4%], p = .049). The rates of profuse/abundant endometrium during hysteroscopy were similar between the no pretreatment (21 [25.0%]) and ulipristal acetate (7 [24.1%], p = .93) groups.

CONCLUSION

Despite differences in surgical nuances, the overall myomectomy experience was not negatively affected by ulipristal acetate pretreatment.

The Rising Phoenix-Progesterone as the Main Target of the Medical Therapy for Leiomyoma

Leiomyomas, also known as uterine fibroids, are a common benign tumor in women of reproductive age. These lesions disrupt the function of the uterus causing menorrhagia and pelvic pressure as well as reproductive disorders. These women pose a true challenge for clinicians in the attempt of choosing the suitable treatment for each patient. Patient's age, interest in fertility preservation, and leiomyoma location and size are all factors to be taken into account when deciding upon the preferable therapeutic option. For the past few decades, surgical treatment was the only reliable long-term treatment available. A variety of surgical approaches have been developed over the years but these developments have come at the expense of other treatment options. The classical medical treatment includes gonadotropin-releasing hormone (GnRH) agonists and antagonists. These agents are well known for their limited clinical effect as well as their broad spectrum of side effects, inspiring a need for new pharmacological treatments. In recent years, promising results have been reported with the use of selective progesterone receptor modulators (SPRM). Long-term clinical trials have shown a reduction in bleeding and shrinkage of leiomyoma mass. These results instill hope for women suffering from symptomatic leiomyomas seeking an effective, long-term medical option for their condition.

Summary of Future Developments

Endometriosis is a chronic disease with the potential to cause devastating clinical manifestations such as infertility and chronic pelvic disease. Current treatment is limited to surgical intervention and pharmacologic therapy targeting estrogen and progesterone to suppress ectopic endometrial tissue proliferation. Undesired side effects and contraindications to the use of hormonal medications may reduce treatment options. As the pathogenesis of endometriosis continues to be investigated, new therapies will emerge. The identification of genes involved in the development of endometriosis may allow targeted therapy to prevent or cure disease. In addition, increasing knowledge of the inflammatory pathways that promote ectopic endometrial growth will permit the development of pharmacologic agents to manipulate these signaling pathways. Utilization of selective progesterone receptor modulators, aromatase inhibitors, and modern gonadotropin-releasing hormone antagonists provide more options to manage disease when traditional treatment fails. Individualized therapeutic strategies will soon be a reality as a greater understanding of endometriosis is obtained through the investigation of genomic studies, molecular pathways, and environmental influences.

Progesterone receptor modulators for endometriosis

BACKGROUND

Endometriosis is defined as the presence of endometrial tissue (glands and stroma) outside the uterine cavity. This condition is oestrogen-dependent and thus is seen primarily during the reproductive years. Owing to their antiproliferative effects in the endometrium, progesterone receptor modulators (PRMs) have been advocated for treatment of endometriosis.

OBJECTIVES

To assess the effectiveness and safety of PRMs primarily in terms of pain relief as compared with other treatments or placebo or no treatment in women of reproductive age with endometriosis.

SEARCH METHODS

We searched the following electronic databases, trial registers, and websites: the Cochrane Gynaecology and Fertility Group (CGFG) Specialised Register of Controlled Trials, the Central Register of Studies Online (CRSO), MEDLINE, Embase, PsycINFO, clinicaltrials.gov, and the World Health Organization (WHO) platform, from inception to 28 November 2016. We handsearched reference lists of articles retrieved by the search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) published in all languages that examined effects of PRMs for treatment of symptomatic endometriosis.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by the Cochrane Collaboration. Primary outcomes included measures of pain and side effects.

MAIN RESULTS

We included 10 randomised controlled trials (RCTs) with 960 women. Two RCTs compared mifepristone versus placebo or versus a different dose of mifepristone, one RCT compared asoprisnil versus placebo, one compared ulipristal versus leuprolide acetate, and four compared gestrinone versus danazol, gonadotropin-releasing hormone (GnRH) analogues, or a different dose of gestrinone. The quality of evidence ranged from high to very low. The main limitations were serious risk of bias (associated with poor reporting of methods and high or unclear rates of attrition in most studies), very serious imprecision (associated with low event rates and wide confidence intervals), and indirectness (outcome assessed in a select subgroup of participants). Mifepristone versus placebo One study made this comparison and reported rates of painful symptoms among women who reported symptoms at baseline.At three months, the mifepristone group had lower rates of dysmenorrhoea (odds ratio (OR) 0.08, 95% confidence interval (CI) 0.04 to 0.17; one RCT, n =352; moderate-quality evidence), suggesting that if 40% of women taking placebo experience dysmenorrhoea, then between 3% and 10% of women taking mifepristone will do so. The mifepristone group also had lower rates of dyspareunia (OR 0.23, 95% CI 0.11 to 0.51; one RCT, n = 223; low-quality evidence). However, the mifepristone group had higher rates of side effects: Nearly 90% had amenorrhoea and 24% had hot flushes, although the placebo group reported only one event of each (1%) (high-quality evidence). Evidence was insufficient to show differences in rates of nausea, vomiting, or fatigue, if present. Mifepristone dose comparisons Two studies compared doses of mifepristone and found insufficient evidence to show differences between different doses in terms of effectiveness or safety, if present. However, subgroup analysis of comparisons between mifepristone and placebo suggest that the 2.5 mg dose may be less effective than 5 mg or 10 mg for treating dysmenorrhoea or dyspareunia. Gestrinone comparisons Ons study compared gestrinone with danazol, and another study compared gestrinone with leuprolin.Evidence was insufficient to show differences, if present, between gestrinone and danazol in rate of pain relief (those reporting no or mild pelvic pain) (OR 0.71, 95% CI 0.33 to 1.56; two RCTs, n = 230; very low-quality evidence), dysmenorrhoea (OR 0.72, 95% CI 0.39 to 1.33; two RCTs, n = 214; very low-quality evidence), or dyspareunia (OR 0.83, 95% CI 0.37 to 1.86; two RCTs, n = 222; very low-quality evidence). The gestrinone group had a higher rate of hirsutism (OR 2.63, 95% CI 1.60 to 4.32; two RCTs, n = 302; very low-quality evidence) and a lower rate of decreased breast size (OR 0.62, 95% CI 0.38 to 0.98; two RCTs, n = 302; low-quality evidence). Evidence was insufficient to show differences between groups, if present, in rate of hot flushes (OR 0.79, 95% CI 0.50 to 1.26; two RCTs, n = 302; very low-quality evidence) or acne (OR 1.45, 95% CI 0.90 to 2.33; two RCTs, n = 302; low-quality evidence).When researchers compared gestrinone versus leuprolin through measurements on the 1 to 3 verbal rating scale (lower score denotes benefit), the mean dysmenorrhoea score was higher in the gestrinone group (MD 0.35 points, 95% CI 0.12 to 0.58; one RCT, n = 55; low-quality evidence), but the mean dyspareunia score was lower in this group (MD 0.33 points, 95% CI 0.62 to 0.04; low-quality evidence). The gestrinone group had lower rates of amenorrhoea (OR 0.04, 95% CI 0.01 to 0.38; one RCT, n = 49; low-quality evidence) and hot flushes (OR 0.20, 95% CI 0.06 to 0.63; one study, n = 55; low quality evidence) but higher rates of spotting or bleeding (OR 22.92, 95% CI 2.64 to 198.66; one RCT, n = 49; low-quality evidence).Evidence was insufficient to show differences in effectiveness or safety between different doses of gestrinone, if present. Asoprisnil versus placebo One study (n = 130) made this comparison but did not report data suitable for analysis. Ulipristal versus leuprolide acetate One study (n = 38) made this comparison but did not report data suitable for analysis.

AUTHORS' CONCLUSIONS

Among women with endometriosis, moderate-quality evidence shows that mifepristone relieves dysmenorrhoea, and low-quality evidence suggests that this agent relieves dyspareunia, although amenorrhoea and hot flushes are common side effects. Data on dosage were inconclusive, although they suggest that the 2.5 mg dose of mifepristone may be less effective than higher doses. We found insufficient evidence to permit firm conclusions about the safety and effectiveness of other progesterone receptor modulators.

An observation study of the clinical evaluation of symptom relief and side effects associated with taking ulipristal acetate (esmya) including its effect on pre-menstrual syndrome

This was an observational study investigating the efficacy and side effects associated with ulipristal acetate (UPA), a progesterone receptor modulator, and the possible benefits to women who have co-existing pre-menstrual syndrome (PMS). 80 women returned a questionnaire on the bleeding, menstrual pain and side effects, and changes on PMS were recorded. 67 women (84%) showed improvement in their menses. 54 women (67%) became amenorrhoeic. Of those, 67% were within 10 days of commencing UPA. Menses returned in 33 amenorrhoeic women within 4 weeks of stopping UPA. 58 women (70%) reported an improvement in their pain score but 41 women had a return of their pain after stopping UPA. The majority of the women had no or infrequent side effects. 80% had demonstrable improvement in their PMS symptoms. UPA is effective in controlling symptoms due to uterine fibroids with infrequent side effects. Our data also showed new evidence of a concurrent dramatic improvement in PMS in these women. Impact statement The observational study explored the drug profile of ulipristal acetate (UPA), a selective progesterone receptor modulator, which has been licenced as pre-treatment for surgical therapies of fibroids since 2012. We aimed to investigate the efficiency and side effects of UPA. Since the introduction of UPA in clinical practice, there has yet to be a study looking at the drug profile outside a research setting. We have also decided to investigate the effect of UPA on pre-menstrual syndrome (PMS) in this group of women with symptomatic fibroids. As such this case report should be of interest to a broad readership including those interested in the medical management of symptomatic fibroids.

Uterine fibroid management: from the present to the future

Uterine fibroids (also known as leiomyomas or myomas) are the most common form of benign uterine tumors. Clinical presentations include abnormal bleeding, pelvic masses, pelvic pain, infertility, bulk symptoms and obstetric complications.Almost a third of women with leiomyomas will request treatment due to symptoms. Current management strategies mainly involve surgical interventions, but the choice of treatment is guided by patient's age and desire to preserve fertility or avoid 'radical' surgery such as hysterectomy. The management of uterine fibroids also depends on the number, size and location of the fibroids. Other surgical and non-surgical approaches include myomectomy by hysteroscopy, myomectomy by laparotomy or laparoscopy, uterine artery embolization and interventions performed under radiologic or ultrasound guidance to induce thermal ablation of the uterine fibroids.There are only a few randomized trials comparing various therapies for fibroids. Further investigations are required as there is a lack of concrete evidence of effectiveness and areas of uncertainty surrounding correct management according to symptoms. The economic impact of uterine fibroid management is significant and it is imperative that new treatments be developed to provide alternatives to surgical intervention.There is growing evidence of the crucial role of progesterone pathways in the pathophysiology of uterine fibroids due to the use of selective progesterone receptor modulators (SPRMs) such as ulipristal acetate (UPA). The efficacy of long-term intermittent use of UPA was recently demonstrated by randomized controlled studies.The need for alternatives to surgical intervention is very real, especially for women seeking to preserve their fertility. These options now exist, with SPRMs which are proven to treat fibroid symptoms effectively. Gynecologists now have new tools in their armamentarium, opening up novel strategies for the management of uterine fibroids.

Epidemiology of Uterine Fibroids: From Menarche to Menopause

Uterine leiomyomata (UL) have a substantial impact on women's health, but relatively few studies have identified opportunities for primary prevention of these neoplasms. Most established risk factors are not modifiable, including premenopausal age, African ancestry, age at menarche, and childbearing history. The main challenge in studying UL is that a large proportion of tumors are asymptomatic. Herein, we review the epidemiology of UL from published studies to date. We highlight the advantages of ultrasound screening studies and the ways in which their innovative methods have helped clarify the etiology of disease. We conclude with a discussion of promising new hypotheses.

Adenomyosis: a systematic review of medical treatment

Adenomyosis is a heterogeneous gynaecologic condition with a range of clinical presentations, the most common being heavy menstrual bleeding and dysmenorrhoea; however, patients can also be asymptomatic. Several studies support the theory that adenomyosis results from invasion of the endometrium into the myometrium, causing alterations in the junctional zone. These changes are commonly seen on imaging studies, such as transvaginal ultrasound and magnetic resonance imaging. The aim of this review is to discuss the medical approach to the management of adenomyosis symptoms, including pain and abnormal uterine bleeding. The standard treatment of adenomyosis is hysterectomy, but there is no medical therapy to treat the symptoms of adenomyosis while still allowing patients to conceive. Medical therapies using suppressive hormonal treatments, such as continuous use of oral contraceptive pills, high-dose progestins, selective oestrogen receptor modulators, selective progesterone receptor modulators, the levonorgestrel-releasing intrauterine device, aromatase inhibitors, danazol, and gonadotrophin receptor hormone agonists can temporarily induce regression of adenomyosis and improve the symptoms.

Endocrinology of uterine fibroids: steroid hormones, stem cells, and genetic contribution

PURPOSE OF REVIEW

Uterine fibroids are extremely common, and can cause significant morbidity, yet the exact cause of these tumors remains elusive and there are currently no long-term treatments available. In this review, we aim to provide an overview of steroid hormones, genetic abnormalities, and stem cells in the pathogenesis of uterine fibroids.

RECENT FINDINGS

A universal feature of fibroids is responsiveness to estrogen and progesterone, and most of the currently available therapies exploit this characteristic. Ulipristal acetate has recently shown particular promise for providing long-term relief from uterine fibroids. Additionally, fibroid stem cells were isolated and appear to be necessary for growth. The recent discovery of somatic mutations involving mediator subunit complex 12 (MED12) or high-mobility group AT-hook 2 (HMGA2) in the majority of fibroids and the links to their pathophysiology were also significant advances.

SUMMARY

The recent shift in focus from hormones to fibroid stem cells and genetic aberrations should lead not only to a deeper understanding of the specific cause of fibroids, but also to the discovery of new therapeutic targets. Targeting the products of genetic mutations or fibroid stem cells has the potential to achieve both better control of current tumors and the prevention of new fibroids.

Progesterone receptor antagonism inhibits progestogen-related carcinogenesis and suppresses tumor cell proliferation

PURPOSE

Blockade of the progestogen-progesterone receptor (PR) axis is a novel but untested strategy for breast cancer prevention. We report preclinical data evaluating telapristone acetate (TPA), ulipristal acetate (UPA), and mifepristone.

METHODS

Tumors were induced with medroxyprogesterone acetate (MPA) plus 7,12-dimethylbenz[a]anthracene (DMBA) in mice, and MPA or progesterone plus N-methyl-N-nitrosourea (MNU) in rats. Mammary gland histology, tumor incidence, latency, multiplicity, burden and histology were evaluated, along with immunohistochemical labeling of pHH3 (proliferation), CD34 (angiogenesis), and estrogen and progesterone receptors (ER and PR). A concentration gradient of TPA, UPA, and mifepristone was tested for growth inhibition of T47D spheroids.

RESULTS

In mouse mammary glands, no tumors formed, but TPA opposed the pro-hyperplastic effects of MPA (p = 0.002). In rats, TPA decreased tumor incidence (p = 0.037 for MPA + TPA vs. MPA, and p = 0.032 for progesterone + TPA vs. progesterone) and tumor burden (p = 0.042 for progesterone + TPA vs. progesterone), with significant decreases in pHH3 and CD34 positive cells. TPA and UPA were superior to mifepristone in growth inhibition of T47D spheroids.

CONCLUSION

TPA has consistent anti-tumorigenic effects in several models, which are accompanied by decreases in cell proliferation, angiogenesis, and hormone receptor expression.

Ulipristal acetate for use in moderate to severe symptoms of uterine fibroids

Although it has been known for a long time that uterine fibroids respond to changes in sex steroid concentrations, it is the availability of selective progesterone receptor modulators such as ulipristal acetete that has provided the gynecologist with a novel option for medical management of uterine fibroids. Ulipristal acetate is presently licensed in Europe for use in women with symptomatic fibroids up to 3 months prior to surgery and has demonstrated good clinical efficacy and safety for this indication. Future trials will define the long-term safety of this drug and its role in medical management of uterine fibroids.

Medical treatment for adenomyosis and/or adenomyoma

Uterine adenomyosis and/or adenomyoma is characterized by the presence of heterotopic endometrial glands and stroma within the myometrium, >2.5 mm in depth in the myometrium or more than one microscopic field at 10 times magnification from the endometrium-myometrium junction, and a variable degree of adjacent myometrial hyperplasia, causing globular and cystic enlargement of the myometrium, with some cysts filled with extravasated, hemolyzed red blood cells, and siderophages. Hysterectomy is a "gold standard" and definitive therapy for uterine adenomyosis, and many cases of adenomyosis have been diagnosed by pathological review retrospectively. As such, the diagnosis of adenomyosis is difficult, and this subsequently results in difficulty in the management of these patients, especially those who are symptomatic but have a strong desire to preserve their uterus. In our previous review, we found that the use of uterine-sparing surgery in the management of uterine adenomyosis and/or adenomyoma is still controversial, although some data support its feasibility. Conservative treatment is still needed in the group of patients that requires preservation of fertility and improvement of quality of life. However, studies focusing on the topic of medical treatment for adenomyosis are rare. In this article, current knowledge regarding the use of medical therapy for uterine adenomyosis, partly based on the understanding of endometriosis, is reviewed.

In vitro-assessment of putative antiprogestin activities of phytochemicals and synthetic UV absorbers in human endometrial Ishikawa cells

Critical steps of embryo implantation are controlled by progesterone. These processes can be interrupted by progesterone receptor (PR) antagonists, e.g. drugs used for abortion. Antiprogestin effects induced by natural compounds and environmental chemicals have been rarely addressed. In our in vitro study, we investigated putative antiprogestin activities of the plant compounds apigenin (API) and trans-ferulic acid (t-FA) as well as the UV absorbers octyl methoxycinnamate (OMC) and 4-methylbenzylidene camphor (4-MBC). They were compared with the selective progesterone receptor modulators (SPRMs) mifepristone (RU486) and ulipristal acetate (UPA) as well as the full PR-antagonist ZK137316. Effects of test compounds in combination with progesterone on the progesterone-sensitive target gene estrogen sulfotransferase (SULT1E1) were characterized by sigmoidal concentration-response curves obtained by RT-qPCR. The agonistic effect of progesterone on SULT1E1 mRNA levels was concentration-dependently antagonized by RU486, UPA and ZK137316 as well as, with lower potency, apigenin. t-FA, OMC and 4-MBC had no effect on SULT1E1 mRNA levels. We demonstrated that apigenin, although at higher concentrations, exerts a similar effect as the well-characterized SPRMs RU486 and UPA or the progesterone antagonist ZK137316 in this model. Our endometrium-specific Ishikawa cell assay is a useful complement to artificial transactivation assays for the identification of environmental substances with antiprogestin activities.

Utilization of human nuclear receptors as an early counter screen for off-target activity: a case study with a compendium of 615 known drugs

Off-target effects of drugs on nuclear hormone receptors (NHRs) may result in adverse effects in multiple organs/physiological processes. Reliable assessments of the NHR activities for drug candidates are therefore crucial for drug development. However, the highly permissive structures of NHRs for vastly different ligands make it challenging to predict interactions by examining the chemical structures of the ligands. Here, we report a detailed investigation on the agonistic and antagonistic activities of 615 known drugs or drug candidates against a panel of 6 NHRs: androgen, progesterone, estrogen α/β, and thyroid hormone α/β receptors. Our study revealed that 4.7 and 12.4% compounds have agonistic and antagonistic activities, respectively, against this panel of NHRs. Nonetheless, potent, unintended NHR hits are relatively rare among the known drugs, indicating that such interactions are perhaps not tolerated during drug development. However, we uncovered examples of compounds that unintentionally agonize or antagonize NHRs. In addition, a number of compounds showed multi-NHR activities, suggesting that the cross-talk between multiple NHRs co-operate to elicit in vivo effects. These data highlight the merits of counter screening drug candidate against NHRs during drug discovery/development.

Progesterone receptor signaling in the initiation of pregnancy and preservation of a healthy uterus

Infertility and reproductive-associated disease are global problems in the world today affecting millions of women. A successful pregnancy requires a healthy uterus ready to receive and support an implanting embryo. As an endocrine organ, the uterus is dependent on the secretions of the ovarian hormones estrogen and progesterone which signal via their cognate receptors, the estrogen and progesterone receptors. The progesterone receptor not only functions using classical nuclear receptor signaling, but also participates in non-genomic signaling at the cellular membrane. The complexity of progesterone signaling is further enhanced by the existence of multiple isoforms and post-translational regulation via kinases and transcription coregulators. This dynamic means of regulation of the progesterone receptor is evidenced in its necessary role in a successful pregnancy. Within early pregnancy, the progesterone receptor elicits activation of its target genes in a spatiotemporal manner in order to allow for successful embryo attachment and uterine decidualization. Additionally, appropriate progesterone signaling is important for the prevention of uterine disease such as endometrial cancer, endometriosis, and leiomyoma. The utilization of progesterone receptor modulators in the treatment of these devastating uterine diseases is promising. This review presents a general overview of progesterone receptor structure, function, and regulation and highlights its important role in the establishment of pregnancy and as a therapeutic target in uterine disease.

Contemporary management of uterine fibroids: focus on emerging medical treatments

OBJECTIVE

This review provides an overview of therapeutic options, with a specific focus on the emerging role of medical options for UF management.

RESEARCH DESIGN AND METHODS

PubMed, Google Scholar, and Cochrane Systematic Reviews were searched for articles published between 1980 and 2013. Relevant articles were identified using the following terms: 'uterine fibroids', 'leiomyoma', 'heavy menstrual bleeding', and 'menorrhagia'. The reference lists of articles identified were also searched for other relevant publications.

RESULTS

Because of the largely benign nature of UFs, the most conservative options that minimize morbidity/risk and optimize outcomes should be considered. Watchful waiting, or no immediate intervention combined with regular follow-up, is an appropriate option for the majority of UF patients who experience no symptoms. For women with symptomatic UFs, the optimal treatment should restore quality of life through rapid relief of UF signs and symptoms, reduce tumor size for a sustained period, and maintain or improve fertility. Invasive surgical treatments, such as hysterectomy, have historically been the mainstay of UF treatment. Less invasive surgical and interventional techniques, such as myomectomy, uterine artery embolization, endometrial ablation, and myolysis provide alternatives to hysterectomy. Until recently, medical management of UFs was characterized by short-term treatments and therapies that provided symptomatic control. In addition to controlling abnormal uterine bleeding, newer medical therapies, including the recently Health-Canada-approved ulipristal acetate, act directly to shrink the tumor. Although no agent is currently approved for such use, emerging evidence suggests the potential for long-term medical management of UFs.

CONCLUSIONS

The advent of novel medical therapies may diminish the long-held reliance on more invasive surgical UF treatment options.

Synthesis and biological evaluation of 11' imidazolyl antiprogestins and mesoprogestins

Antiprogestins with a 4' para imidazolylphenyl moiety were synthesized and their biochemical interactions with the progesterone and glucocorticoid receptor were investigated. Depending on the substitution pattern at the 17 position partial progesterone receptor (PR)-agonistic derivatives like compounds EC339 and EC336 or pure antagonists like compound EC317 were obtained. EC317 was investigated in vivo and found to be significantly more potent than RU 486 in cycling and pregnant guinea pigs. For testing the biological action progesterone receptor modulators (PRM), guinea pigs appears as a specific model when compare to pregnant human uterus. This model correlates to human conditions such as softening and widening of the cervix, the elevation of the uterine responsiveness to prostaglandins and oxytocin, and finally to induction of labor. The use of non-pregnant guinea pigs permitted the simultaneous assessment of PR-agonistic and PR-antagonistic properties and their physiological interactions with uterine and vaginal environment. These can histologically be presumed from the presence of estrogen or progesterone dominance in the genital tract tissues. The ovarian histology indicated the effects on ovulation. Corpora lutea in guinea pigs further reflects inhibitory effects of the progesterone-dependent uterine prostaglandin secretion. PRMs are initially synthesized as analogues of RU 486. They represent a heterogeneous group of compounds with different ratios of PR-agonistic and-antagonistic properties. PR-agonistic properties may be essential for uterine anti-proliferative effects. In various clinical studies these were also attributed to RU 486 or Ulipristal [1,2]. Adjusted PR-agonistic PRMs (EC312, EC313) [3] may be more effective in achieving a mitotically resting endometrium and superior uterine tumor inhibition. For the use in termination of pregnancy, progesterone-inhibitory effects are essentially needed. Even minor PR-agonistic properties compromise the therapeutic goals. Pure PR-antagonists, as EC317, clearly exceeded the gold standard RU 486 with respect to labor inducing effects. Mechanistically it is surprising that both types of compound may be potent inhibitors of ovulation.

Role of nuclear progesterone receptor isoforms in uterine pathophysiology

BACKGROUND

Progesterone is a key hormonal regulator of the female reproductive system. It plays a major role to prepare the uterus for implantation and in the establishment and maintenance of pregnancy. Actions of progesterone on the uterine tissues (endometrium, myometrium and cervix) are mediated by the combined effects of two progesterone receptor (PR) isoforms, designated PR-A and PR-B. Both receptors function primarily as ligand-activated transcription factors. Progesterone action on the uterine tissues is qualitatively and quantitatively determined by the relative levels and transcriptional activities of PR-A and PR-B. The transcriptional activity of the PR isoforms is affected by specific transcriptional coregulators and by PR post-translational modifications that affect gene promoter targeting. In this context, appropriate temporal and cell-specific expression and function of PR-A and PR-B are critical for normal uterine function.

METHODS

Relevant studies describing the role of PRs in uterine physiology and pathology (endometriosis, uterine leiomyoma, endometrial cancer, cervical cancer and recurrent pregnancy loss) were comprehensively searched using PubMed, Cochrane Library, Web of Science, and Google Scholar and critically reviewed.

RESULTS

Progesterone, acting through PR-A and PR-B, regulates the development and function of the endometrium and induces changes in cells essential for implantation and the establishment and maintenance of pregnancy. During pregnancy, progesterone via the PRs promotes myometrial relaxation and cervical closure. Withdrawal of PR-mediated progesterone signaling triggers menstruation and parturition. PR-mediated progesterone signaling is anti-mitogenic in endometrial epithelial cells, and as such, mitigates the tropic effects of estrogen on eutopic normal endometrium, and on ectopic implants in endometriosis. Similarly, ligand-activated PRs function as tumor suppressors in endometrial cancer cells through inhibition of key cellular signaling pathways required for growth. In contrast, progesterone via PR activation appears to increase leiomyoma growth. The exact role of PRs in cervical cancer is unclear. PRs regulate implantation and therefore aberrant PR function may be implicated in recurrent pregnancy loss (RPL). PRs likely regulate key immunogenic factors involved in RPL. However, the exact role of PRs in the pathophysiology of RPL and the use of progesterone for therapeutic benefit remains uncertain.

CONCLUSIONS

PRs are key mediators of progesterone action in uterine tissues and are essential for normal uterine function. Aberrant PR function (due to abnormal expression and/or function) is a major cause of uterine pathophysiology. Further investigation of the underlying mechanisms of PR isoform action in the uterus is required, as this knowledge will afford the opportunity to create progestin/PR-based therapeutics to treat various uterine pathologies.

Ovarian steroids, stem cells and uterine leiomyoma: therapeutic implications

BACKGROUND

Uterine leiomyoma is the most common benign tumor in women and is thought to arise from the clonal expansion of a single myometrial smooth muscle cell transformed by a cellular insult. Leiomyomas cause a variety of symptoms, including abnormal uterine bleeding, pelvic pain, bladder or bowel dysfunction, and recurrent pregnancy loss, and are the most common indication for hysterectomy in the USA. A slow rate of cell proliferation, combined with the production of copious amounts of extracellular matrix, accounts for tumor expansion. A common salient feature of leiomyomas is their responsiveness to steroid hormones, thus providing an opportunity for intervention.

METHODS

A comprehensive search of PUBMED was conducted to identify peer-reviewed literature published since 1980 pertinent to the roles of steroid hormones and somatic stem cells in leiomyoma, including literature on therapeutics that target steroid hormone action in leiomyoma. Reviewed articles were restricted to English language only. Studies in both animals and humans were reviewed for the manuscript.

RESULTS

Estrogen stimulates the growth of leiomyomas, which are exposed to this hormone not only through ovarian steroidogenesis, but also through local conversion of androgens by aromatase within the tumors themselves. The primary action of estrogen, together with its receptor estrogen receptor α (ERα), is likely mediated via induction of progesterone receptor (PR) expression, thereby allowing leiomyoma responsiveness to progesterone. Progesterone has been shown to stimulate the growth of leiomyoma through a set of key genes that regulate both apoptosis and proliferation. Given these findings, aromatase inhibitors and antiprogestins have been developed for the treatment of leiomyoma, but neither treatment results in complete regression of leiomyoma, and tumors recur after treatment is stopped. Recently, distinct cell populations were discovered in leiomyomas; a small population showed stem-progenitor cell properties, and was found to be essential for ovarian steroid-dependent growth of leiomyomas. Interestingly, these stem-progenitor cells were deficient in ERα and PR and instead relied on the strikingly higher levels of these receptors in surrounding differentiated cells to mediate estrogen and progesterone action via paracrine signaling.

CONCLUSIONS

It has been well established that estrogen and progesterone are involved in the proliferation and maintenance of uterine leiomyoma, and the majority of medical treatments currently available for leiomyoma work by inhibiting steroid hormone production or action. A pitfall of these therapeutics is that they decrease leiomyoma size, but do not completely eradicate them, and tumors tend to regrow once treatment is stopped. The recent discovery of stem cells and their paracrine interactions with more differentiated cell populations within leiomyoma has the potential to provide the missing link between developing therapeutics that temper leiomyoma growth and those that eradicate them.

Medical treatments for endometriosis-associated pelvic pain

The main sequelae of endometriosis are represented by infertility and chronic pelvic pain. Chronic pelvic pain causes disability and distress with a very high economic impact. In the last decades, an impressive amount of pharmacological agents have been tested for the treatment of endometriosis-associated pelvic pain. However, only a few of these have been introduced into clinical practice. Following the results of the controlled studies available, to date, the first-line treatment for endometriosis associated pain is still represented by oral contraceptives used continuously. Progestins represent an acceptable alternative. In women with rectovaginal lesions or colorectal endometriosis, norethisterone acetate at low dosage should be preferred. GnRH analogues may be used as second-line treatment, but significant side effects should be taken into account. Nonsteroidal anti-inflammatory drugs are widely used, but there is inconclusive evidence for their efficacy in relieving endometriosis-associated pelvic pain. Other agents such as GnRH antagonist, aromatase inhibitors, immunomodulators, selective progesterone receptor modulators, and histone deacetylase inhibitors seem to be very promising, but there is not enough evidence to support their introduction into routine clinical practice. Some other agents, such as peroxisome proliferator activated receptors-γ ligands, antiangiogenic agents, and melatonin have been proven to be efficacious in animal studies, but they have not yet been tested in clinical studies.

Systemic therapy of Cushing's syndrome

Cushing’s disease (CD) in a stricter sense derives from pathologic adrenocorticotropic hormone (ACTH) secretion usually triggered by micro- or macroadenoma of the pituitary gland. It is, thus, a form of secondary hypercortisolism. In contrast, Cushing’s syndrome (CS) describes the complexity of clinical consequences triggered by excessive cortisol blood levels over extended periods of time irrespective of their origin. CS is a rare disease according to the European orphan regulation affecting not more than 5/10,000 persons in Europe. CD most commonly affects adults aged 20–50 years with a marked female preponderance (1:5 ratio of male vs. female). Patient presentation and clinical symptoms substantially vary depending on duration and plasma levels of cortisol. In 80% of cases CS is ACTH-dependent and in 20% of cases it is ACTH-independent, respectively. Endogenous CS usually is a result of a pituitary tumor. Clinical manifestation of CS, apart from corticotropin-releasing hormone (CRH-), ACTH-, and cortisol-producing (malign and benign) tumors may also be by exogenous glucocorticoid intake. Diagnosis of hypercortisolism (irrespective of its origin) comprises the following: Complete blood count including serum electrolytes, blood sugar etc., urinary free cortisol (UFC) from 24 h-urine sampling and circadian profile of plasma cortisol, plasma ACTH, dehydroepiandrosterone, testosterone itself, and urine steroid profile, Low-Dose-Dexamethasone-Test, High-Dose-Dexamethasone-Test, after endocrine diagnostic tests: magnetic resonance imaging (MRI), ultra-sound, computer tomography (CT) and other localization diagnostics. First-line therapy is trans-sphenoidal surgery (TSS) of the pituitary adenoma (in case of ACTH-producing tumors). In patients not amenable for surgery radiotherapy remains an option. Pharmacological therapy applies when these two options are not amenable or refused. In cases when pharmacological therapy becomes necessary, Pasireotide should be used in first-line in CD. CS patients are at an overall 4-fold higher mortality rate than age- and gender-matched subjects in the general population. The following article describes the most prominent substances used for clinical management of CS and gives a systematic overview of safety profiles, pharmacokinetic (PK)-parameters, and regulatory framework.

Selective progesterone receptor modulators: an update

INTRODUCTION

Several selective progesterone receptor modulators (SPRMs) show promise in several areas of medicine and this work has been summarized by us in 2008.

AREAS COVERED

Since the publication of our reviews, several developments have taken place in the field of reproductive medicine. The first is emergency contraception (EC). Two SPRMs are clinically utilized today: mifepristone (MFP) and ulipristal acetate (UPA). MFP is available for EC in up to 120 h following unprotected intercourse. A dose of 10 mg is significantly more effective than levonorgestrel (LNG). In a metanalysis of the use of UPA versus LNG up to 72 h after unprotected intercourse, failure rates of 1.4 versus 2.2% were reported. The second is contraception. A daily dose of 2 mg MFP can block ovulation and several MFP regimens are being tested, including a vaginal ring releasing MFP. The third is the preoperative administration in women harboring leiomyomas, where clinical testing of several SPRM has shown that they can decrease uterine leiomyomas' size and substantially reduce uterine bleeding. SPRM can induce unusual, specific endometrial appearances. Many believe that these changes should not cause concern, but the issue remains controversial.

EXPERT OPINION

SPRMs are very effective in EC and for the preoperative treatment of uterine leiomyomas.

Resistance to cisplatin and paclitaxel does not affect the sensitivity of human ovarian cancer cells to antiprogestin-induced cytotoxicity

Background

Antiprogestin compounds have been shown to be effective in blocking the growth of ovarian cancer cells of different genetic backgrounds. Herein we studied the anti-ovarian cancer effect of a series of antiprogestins sharing the chemical backbone of the most characterized antiprogestin, mifepristone, but with unique modifications in position C-17 of the steroid ring. We assessed the effect of mifepristone-like antiprogestins on the growth of ovarian cancer cells sensitive to the standard combination therapy cisplatin-paclitaxel or made double-resistant upon six cycles of pulse-selection with the drugs used at clinically relevant concentrations and exposure times.

Methods

IGROV-1 and SKOV-3 cells were pulsed with 20 μM cisplatin for 1 h followed by 100 nM paclitaxel for 3 h once a week for six weeks. The cells that did not die and repopulate the culture after the chemotherapies were termed Platinum-Taxane-EScape cells (PTES). Parental cells were compared against their PTES derivatives in their responses to further platinum-taxane treatments. Moreover, both ovarian cancer cells and their PTES siblings were exposed to escalating doses of the various antiprogestin derivatives. We assessed cell growth, viability and sub-G1 DNA content using microcapillary cytometry. Cyclin-dependent kinase inhibitors p21^cip1 and p27^kip1 and cleavage of downstream caspase-3 substrate PARP were used to assess whether cell fate, as a consequence of treatment, was limited to cytostasis or progressed to lethality.

Results

Cells subjected to six pulse-selection cycles of cisplatin-paclitaxel gave rise to sibling derivatives that displayed ~2-7 fold reduction in their sensitivities to further chemotherapy. However, regardless of the sensitivity the cells developed to the combination cisplatin-paclitaxel, they displayed similar sensitivity to the antiprogestins, which blocked their growth in a dose-related manner, with lower concentrations causing cytostasis, and higher concentrations causing lethality.

Conclusions

Antiprogestins carrying a backbone similar to mifepristone are cytotoxic to ovarian cancer cells in a manner that does not depend on the sensitivity the cells have to the standard ovarian cancer chemotherapeutics, cisplatin and paclitaxel. Thus, antiprogestin therapy could be used to treat ovarian cancer cells showing resistance to both platinum and taxanes.

Ulipristal acetate: a novel pharmacological approach for the treatment of uterine fibroids

Uterine fibroids are the most common benign tumors of the female genital tract. The management of symptomatic fibroids has traditionally been surgical; however, alternative pharmacological approaches have been proposed to control symptoms. To date, gonadotropin-releasing hormone analogs are the only available drugs for the preoperative treatment of fibroids. However, the US Food and Drug Administration recently authorized ulipristal acetate (UPA), an oral selective progesterone-receptor modulator, for the same indication. UPA is a new, effective, and well-tolerated option for the preoperative treatment of moderate and severe symptoms of uterine fibroids in women of reproductive age. According to clinical data, UPA shows several advantages: it is faster than leuprolide in reducing the fibroid-associated bleeding, it significantly improves hemoglobin and hematocrit levels in anemic patients, and it grants a significant reduction in the size of fibroids, which lasts for at least 6 months after the end of the treatment. Furthermore, UPA displays a better tolerability profile when compared to leuprolide; in fact, it keeps estradiol levels at mid follicular phase range, thereby reducing the incidence of hot flushes and exerting no impact on bone turnover. On the grounds of this evidence, the administration of 5 mg/day ulipristal acetate for 3 months is suggested for different patient categories and allows for planning a treatment strategy tailored to meet an individual patient's needs.