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Purpose: The contraceptive gestodene is a potent synthetic progestin used in several low-dose contraceptive formulations. Clinical studies reported a relationship between long-term use of combined oral contraceptives containing gestodene (GDN) and profound alterations in glucose metabolism in women. The observation that contraceptive synthetic progestins exert hormone-like effects other than their progestational activities, prompted us to investigate whether GDN may induce estrogen-like effects, even though GDN does not interact with estrogen receptors. The aim of this study was to investigate whether GDN affect pancreatic β-cell activity, directly or through its conversion to other bioactive metabolites., Methods: The effects of GDN and its two derivatives 3β,5α-tetrahydro-GDN and 3α,5α-tetrahydro-GDN on insulin 2 (Ins II) and glucokinase (Gk) expression and glucose-stimulated insulin secretion were determined in pancreatic islets from female rats., Results: Gestodene did exert significant effects on islet β-cells activity. The most striking finding was that 3β,5α-tetrahydro-GDN and 3α,5α-tetrahydro-GDN had greater stimulatory effects on Ins II and Gk expression than that observed with GDN, consistent with their effects on glucose-stimulated insulin secretion. The effects on gene expression induced by GDN-derivatives were abolished by ICI 182,780 and MPP. In addition, the presence of inhibitors of androgen and progestin-metabolizing enzymes eliminated gene expression induced by GDN. These results indicated that GDN is metabolized to A-ring reduced metabolites with estrogen-like activities and through this mechanism, GDN may affect β-cell activity., Conclusions: Altogether, the data suggest that 19-nortestosterone-derived contraceptives such as GDN, possess insulinotropic effects through their conversion into metabolites with intrinsic estrogen-like activity in pancreatic β-cells., (© 2023. The Author(s), under exclusive licence to Italian Society of Endocrinology (SIE).)

Steroid hormones are the key regulators of inflammatory and autoimmune processes. The role of steroid hormones is mostly inhibitory in these processes. The expression of IL-6, TNFα, and IL-1β, as markers of inflammation, and TGFβ, as a marker of fibrosis, could be useful tools to predict the response of an individual's immune system to the different progestins suitable for the treatment of menopausal inflammatory disorders, including endometriosis. In this study, the progestins P4 and MPA, as well as the novel progestin gestobutanoyl (GB), which possess potent anti-inflammatory properties towards endometriosis, were studied at a fixed concentration of 10 µM. Their influence on the production of the above cytokines in PHA-stimulated peripheral blood mononuclear cells (PBMCs) during 24 h incubation was evaluated by ELISA. It was found that synthetic progestins stimulated the production of IL-1β, IL-6, and TNFα and inhibited TGFβ production, while P4 inhibited IL-6 (33% inhibition) and did not influence TGFβ production. In the MTT-viability test, P4 also decreased PHA-stimulated PBMC viability by 28% during 24 h incubation, but MPA and GB did not have any inhibitory or stimulatory effects. The luminol-dependent chemiluminescence (LDC) assay revealed the anti-inflammatory and antioxidant properties of all the tested progestins, as well as some other steroid hormones and their antagonists: cortisol, dexamethasone, testosterone, estradiol, cyproterone, and tamoxifen. Of these, tamoxifen showed the most pronounced effect on the oxidation capacity of PBMC but not on that of dexamethasone, as was expected. Collectively, these data demonstrate that PBMCs from menopausal women respond differently to P4 and synthetic progestins, most likely due to distinct actions via various steroid receptors. It is not only the progestin affinity to nuclear progesterone receptors (PR), androgen receptors, glucocorticoid receptors, or estrogen receptors that is important for the immune response, but also the membrane PR or other nongenomic structures in immune cells.

Studies directly comparing the efficacies and potencies of multiple progestins used in contraception and menopausal hormone therapy (MHT) in parallel via human progesterone receptor isoform A (PR-A) in the same model system are limited, and how these parameters are influenced by the density of PR-A are unclear. This is surprising as it is known that the expression levels of PR-A vary in different tissues and diseases. We thus determined for the first time the relative efficacies and potencies for transactivation of the natural PR ligand, progesterone (P 4 ), the PR-specific agonist promegestone (R5020), and selected progestins from all four generations in parallel via different densities of PR-A overexpressed in the MDA-MB-231 breast cancer cell line. Comparative dose-response analysis showed that P 4 , R5020, the 1st generation progestins medroxyprogesterone acetate and norethisterone, 2nd generation progestin levonorgestrel, 3rd generation progestin gestodene, as well as 4th generation progestins nesterone, nomegestrol acetate and drospirenone display differential agonist efficacies and potencies via PR-A. Moreover, we showed that the agonist efficacies and potencies of the progestins via PR-A were modulated in a density- and progestin-specific manner. Our finding that the potencies of the progestins via PR-A, at all densities, do not exceed reported progestin serum concentrations in women, suggest that these progestins are likely to elicit similar effects in vivo. We are the first to report that P 4 and the selected progestins display similar agonist activity for transrepression via PR-A, and that the density of PR-A enhances the transrepression activity of some, but not all progestogens. Collectively, our findings provide proof of concept that the effects of the selected progestins via PR-A is progestin-specific and dependent on the density of the receptor, suggesting differential progestin responses in women using these progestins in contraception and MHT., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

The objective of the present study was to assess the effects of levonorgestrel (LNG), a synthetic progestin, on early development and the thyroid system of carp using morphological, histological, immunohistochemical, and gene expression analysis. Fish were exposed to LNG at three levels (3, 31, and 310 ng L -1 ) from eggs to the onset of juvenile stage (47 days). LNG had no significant effect on early development in common carp or on the occurrence of morphological anomalies. No pathological alterations of the thyroid follicles were found. Immunohistochemical examination of the thyroid follicles using antibodies against thyroxin did not show any differences in fish exposed to 310 ng L -1 LNG compared to the controls. mRNA expression of iodothyronine deiodinases (dio1, 2, 3) was differentially affected by LNG treatment during carp development. Most importantly, dio3 was markedly downregulated in fish exposed to all three LNG levels compared to the controls at the conclusion of the experiment (47 days post-fertilization). A decrease in dio1 or dio3 or an increase in dio2 transcription observed at different time points of the study may be a sign of hypothyroidism. mRNA expression of genes npr, esr1, and esr2b in the body and npr and esr2b in the head of fish exposed to 310 ng L -1 LNG was significantly upregulated compared to the solvent control group at the end of the test. Together, these results show that levonorgestrel caused parallel changes in the hypothalamus-pituitary-thyroid and hypothalamus-pituitary-gonad axes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Introduction: In this paper, we report general pharmacological profile and major biological activities of natural progesterone (P) and progestins. The aim of this article consists of synthesizing the principal aspects of pharmacology and metabolism of P and progestins related to the clinical consequences of their use., Evidence Acquisition: We review scientific literature on the topic "progestins," evaluating the most relevant data from original articles, reviews, and meta-analyses., Evidence Synthesis: Progestins represent a specific class of synthetic analogues of P clinically employed (alone or associated with estrogens) to manage several gynecological conditions, for instance multiple abortions, luteal phase defect, premenstrual syndrome, abnormal uterine bleeding, endometriosis, and menopause (for hormone replacement therapy). Besides their use in the field of contraception, many non-contraceptive benefits of estroprogestins are mostly due to the activities of progestins. Pharmacological characteristics, dosage and individual metabolism could be listed among the principal aspects influencing their clinical effects., Conclusions: The choice of each progestin according to its pharmacological profile is crucial for the appropriate management of any gynecological condition. An aware knowledge of these compounds is fundamental to hone medical practice.

Antiretroviral therapy has slowed the HIV/AIDS pandemic and is currently being used as a prophylactic measure for individuals at high risk of infection. However, concerns over adverse effects of long-term use need to be explored. We hypothesize that this may occur, at least in part, through off-target effects via select steroid receptors (SRs) that broadly regulate multiple physiological processes. We investigated the effects of maraviroc (MVC), tenofovir disoproxil fumarate (TDF), and dapivirine (DPV) on progesterone receptor B (PR-B) transcriptional activity. We found that MVC and TDF activate PR-B transcription in the absence of progestogens on a PR-regulated promoter reporter construct and on endogenous PR-regulated genes. MVC and TDF exhibited no direct binding to PR-B; however, increased PR-B phosphorylation was detected with TDF but not MVC. DPV transactivated gilz and ptgs2 in the absence of progestogens and exhibited PR-B binding while showing no effects on phosphorylation, suggesting that it may activate PR-B through a direct mechanism. Our study shows that potential off-target immunomodulatory effects of MVC, TDF and DPV occur in vitro and these are most likely mediated by different mechanisms of PR-B activation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The current ovarian cycle paradigm postulates that ovulation is triggered by a critically sustained elevation of estradiol. However, an in-depth look into the published data reveals considerable uncertainty about the relative roles of progesterone and estradiol in the ovulation process.This review provides compelling evidences that the role of estradiol in ovulation has been misinterpreted and that the true physiological trigger of ovulation is a luteinizing hormone-independent preovulatory progesterone surge in the circulation to approximately 0.5 ng/mL. Furthermore, the current work reconciles the ability of progesterone to trigger ovulation, with its well-established ability to block ovulation during pregnancy, or when administered in the form of a synthetic progestin in birth control formulations and with experimental data that estradiol benzoate triggers ovulation in the complete absence of progesterone., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Abnormal uterine bleeding (AUB) is a chronic, debilitating and common condition affecting one in four women of reproductive age. Current treatments (conservative, medical and surgical) may be unsuitable, poorly tolerated or may result in loss of fertility. Selective progesterone receptor modulators (SPRMs) influence progesterone-regulated pathways, a hormone critical to female reproductive health and disease; therefore, SPRMs hold great potential in fulfilling an unmet need in managing gynaecological disorders. SPRMs in current clinical use include RU486 (mifepristone), which is licensed for pregnancy interruption, and CDB-2914 (ulipristal acetate), licensed for managing AUB in women with leiomyomas and in a higher dose as an emergency contraceptive. In this article, we explore the clinical journey of SPRMs and the need for further interrogation of this class of drugs with the ultimate goal of improving women's quality of life.

Natural and synthetic estrogens and progestins are widely used in human and veterinary medicine and are detected in waste and surface waters. Our previous studies have clearly shown that a number of these substances targets the brain to induce the estrogen-regulated brain aromatase expression but the consequences on brain development remain virtually unexplored. The aim of the present study was therefore to investigate the effect of estradiol (E2), progesterone (P4) and norethindrone (NOR), a 19-nortestosterone progestin, on zebrafish larval neurogenesis. We first demonstrated using real-time quantitative PCR that nuclear estrogen and progesterone receptor brain expression is impacted by E2, P4 and NOR. We brought evidence that brain proliferative and apoptotic activities were differentially affected depending on the steroidal hormone studied, the concentration of steroids and the region investigated. Our findings demonstrate for the first time that steroid compounds released in aquatic environment have the capacity to disrupt key cellular events involved in brain development in zebrafish embryos further questioning the short- and long-term consequences of this disruption on the physiology and behavior of organisms., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Nomegestrol acetate (NOMAc) is a synthetic progesterone analog and classified as a fourth-generation progestin. It has been approved in many countries for oral contraception, hormonal replacement therapy (HRT), and treatment of various gynecological disorders. There are several synthetic routes reported for the synthesis of NOMAc and they all share the very similar last three to five steps toward the conversion of 6-methylene to 6-methyl-6,7-unsaturated structure. Therefore the final product from different processing routes may have similar impurity profiles. In the analysis of NOMAc, we identified two impurities, impurity A (listed in EP 8.0) and impurity B (not specified in EP 8.0). Both impurities were further confirmed by synthesis. In addition, both impurities and NOMAc were evaluated for their in vitro cytotoxicities against L02 liver cells, mesenchymal stem cells, MCF-7 breast cancer cells, and C33A cervical cancer cells. These three analogs are not cytotoxic to the four cell lines at low concentrations (<20 μM). NOMAc and impurity A showed cytotoxicity to L02, MCF-7, and C33A cells at high concentrations, while impurity B did not show significant cytotoxicity to any of the cell lines tested., (© 2019 Deutsche Pharmazeutische Gesellschaft.)

The effects of some progestins on fish reproduction have been recently reported revealing the hazard of this class of steroidal pharmaceuticals. However, their effects at the central nervous system level have been poorly studied until now. Notwithstanding, progesterone, although still widely considered primarily a sex hormone, is an important agent affecting many central nervous system functions. Herein, we investigated the effects of a large set of synthetic ligands of the nuclear progesterone receptor on the glial-specific expression of the zebrafish brain aromatase (cyp19a1b) using zebrafish mechanism-based assays. Progesterone and 24 progestins were first screened on transgenic cyp19a1b-GFP zebrafish embryos. We showed that progesterone, dydrogesterone, drospirenone and all the progesterone-derived progestins had no effect on GFP expression. Conversely, all progestins derived from 19-nortesterone induced GFP in a concentration-dependent manner with EC50 ranging from the low nM range to hundreds nM. The 19-nortestosterone derived progestins levonorgestrel (LNG) and norethindrone (NET) were further tested in a radial glial cell context using U251-MG cells co-transfected with zebrafish ER subtypes (zfERα, zfERβ1 or zfERβ2) and cyp19a1b promoter linked to luciferase. Progesterone had no effect on luciferase activity while NET and LNG induced luciferase activity that was blocked by ICI 182,780. Zebrafish-ERs competition assays showed that NET and LNG were unable to bind to ERs, suggesting that the effects of these compounds on cyp19a1b require metabolic activation prior to elicit estrogenic activity. Overall, we demonstrate that 19-nortestosterone derived progestins elicit estrogenic activity by inducing cyp19a1b expression in radial glial cells. Given the crucial role of radial glial cells and neuro-estrogens in early development of brain, the consequences of exposure of fish to these compounds require further investigation., (Copyright © 2016. Published by Elsevier Inc.)

Objective: To investigate the efficacy and safety of the long-acting altrenogest injection (NV Readyserve® injection) for horses., Design: A single-dose pharmacokinetic (PK) study was conducted. The in vivo efficacy study was a blinded, repeated measures design evaluating behaviour scores. The safety study was a non-blinded, controlled, parallel-group, randomised-block design as per the VICH protocol., Methods: In the PK study, serial blood samples were obtained for analysis of plasma altrenogest for 150 h following the injection and a non-compartmental PK analysis was performed. For the efficacy study, 12 mares in oestrus were treated; they were monitored daily for 10 days for signs of oestrus during teasing and given a behaviour score that was compared with pretreatment scores. A standard safety study was conducted at 1-, 3- and 5-fold the recommended dosage for 84 days. Physical, haematological and biochemical examinations were performed., Results: Mean plasma altrenogest concentrations were greater than ≈0.5 ng/mL for 148 h following administration. Oestrous behaviour was suppressed in all mares within 24 h of administration. Two mares returned to oestrus by day 6 and the rest on days 7-10. In the safety study there were no significant differences in the physical and haematological examinations, but minor biochemical changes in muscle enzymes. There was a low incidence of injection site reactions following the 3- and 5-fold dose, predominantly for pectoral injections., Conclusion: These studies support the efficacy and safety of a single dose of Readyserve® injection for the suppression of the signs of oestrus in mares for 5-7 days., (© 2016 Australian Veterinary Association.)

The use of intravaginal sponges (IS) to synchronize estrous onset in ewes provokes vaginitis, an increase in the vaginal bacterial load, and growth of bacterial species that are not present during spontaneous estrous behavior. The objective of the study was to compare the functional sperm parameters after incubating it with mucus collected from the vagina of ewes during spontaneous estrus or estrous synchronized with IS. Pooled spermatozoa were co-incubated with: (1) vaginal mucus collected from ewes in spontaneous estrus; (2) vaginal mucus collected from ewes in estrus pretreated with progestogen-impregnated IS; (3) synthetic mucus; and (4) medium without mucus as a control group. Sperm samples were evaluated after incubating it for 30 and 90 minutes. The number of colony-forming units (CFUs/mL), pH, and osmolality were greater in the mucus collected from ewes treated with IS than from those untreated (P = 0.046; P < 0.0001, and P < 0.0001, respectively). The percentage of sperm with progressive motility was lower after incubation with vaginal mucus collected from estrous ewes treated with IS than in the other three treatments both, 30 and 90 minutes after incubation (P = 0.0009 and P < 0.0001, respectively). The sample incubated for 30 minutes with mucus from ewes treated with IS had a lower percentage of sperm with intact plasma membrane than all the other treatments (P < 0.0001). The percentage of sperm with functional membrane was significantly lower in the sample incubated for 30 minutes with vaginal mucus from ewes treated with IS than in the other three treatments (P < 0.0001). After 90 minutes, the percentage was still lower than that in the sample collected from ewes during their spontaneous estrus (P = 0.0005). The lowest percentages of sperm with acrosome damage were observed in sperm incubated with mucus collected from sheep in spontaneous estrus for 30 and 90 minutes (P < 0.0001 and P = 0.008, respectively). The percentage of apoptotic spermatozoa was greater in samples incubated during 30 minutes with vaginal mucus collected from ewes treated with IS than in the other three groups (P = 0.0005). The functionality and the viability of ram sperm is negatively affected by the cervical mucus of ewes pretreated with progestagen-impregnated IS used in estrous synchronization treatments. This may partially explain the decrease in conception rate obtained with treatments with IS., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Dienogest (DNG) is a selective progesterone receptor (PR) agonist and oral administration of DNG is used for the treatment of endometriosis. DNG is considered to act on PR to down-regulate pathophysiological factors associated with endometriosis. PR exists as two major isoforms, PR-A and PR-B, and their physiological functions are mostly distinct. It was suggested that PR isoform expression patterns are altered in endometriosis, but it is unknown whether the pharmacological effects of DNG are exerted through PR-A, PR-B or both. In the present study, we investigated the pharmacological effects of DNG through these PR isoforms on the expression of CYP19A1 which encodes aromatase and inflammatory and neuroangiogenesis factors associated with the pain and progression of endometriosis. We used immortalized human endometriotic epithelial cell lines that specifically express PR-A or PR-B in a spheroid cell culture system, and treated them with DNG. We evaluated messenger RNA (mRNA) expression of CYP19A1, prostaglandin (PG)E2 synthase (cyclooxygenase (COX)-2 and microsomal PGE2 synthase (mPGES)-1), inflammatory cytokines (interleukin (IL)-6, IL-8, and monocyte chemoattractant protein (MCP)-1) and neuroangiogenesis factors (vascular endothelial growth factor (VEGF) and nerve growth factor (NGF)) using real-time polymerase chain reaction. In addition, PGE2 production was measured by enzyme immunoassay. We found that DNG down-regulated mRNA expression of CYP19A1, COX-2, mPGES-1, IL-6, IL-8, MCP-1, NGF and VEGF, and PGE2 production in human endometriotic epithelial cell lines that specifically express either PR-A or PR-B. These results demonstrate that DNG activates both PR-A and PR-B and down-regulates the expression of pathophysiological factors associated with pain and progression of endometriosis. Our results suggest that DNG exerts therapeutic efficacy against the pain and progression of endometriosis regardless of PR isoform expression patterns., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Hormone replacement therapy (HRT) is widely used to manage menopausal symptoms in women and can be comprised of an estrogen alone or an estrogen combined with a progestin. The Women's Health Initiative demonstrated in their randomized trials that estrogen alone HRT decreases the risk of breast cancer in postmenopausal women, whereas combined estrogen plus a progestin (medroxyprogesterone acetate, MPA) HRT increases this risk. Long-term estrogen-deprived MCF-7:5C cells were used to model the postmenopausal breast cancer cell environment. MPA is able to modify E2-induced apoptosis in MCF-7:5C cells. MPA, similar to dexamethasone, increases glucocorticoid receptor (GR) transcriptional activity, increases SGK1, a GR target gene, and can be blocked by RU486 (an antiglucocorticoid), suggesting that it functions through the GR. Norethindrone acetate (NETA), another progestin used in HRT, acts like an estrogen at high doses, upregulating estrogen receptor target genes and generating apoptosis in MCF-7:5C cells. The data suggest that women taking HRT comprising an estrogen plus MPA may have an increased risk of breast cancer due to MPA acting as a glucocorticoid and blunting E2-induced apoptosis in this environment. Therefore, perhaps other approved progestins (e.g., NETA) should be considered as alternatives to MPA., (©2014 American Association for Cancer Research.)

Adenomyosis is a common disorder in premenopausal women that causes dysmenorrhea, pelvic pain and menorrhagia. Considering that adenomyosis is an estrogen-dependent disease, the medical treatment is based on this hormone. Effective and well-tolerated medical treatments for symptomatic adenomyosis are needed. Dienogest, an oral progestin, has been extensively investigated in the treatment of endometriosis. In this report, we present the results on the efficacy and safety of dienogest in the treatment of symptomatic adenomyosis. Seventeen patients with symptomatic adenomyosis were included in this study, of which 15 continued dienogest for up to 24 weeks. Dienogest significantly reduced adenomyosis-associated pelvic pain as well as serum CA-125 and CA19-9 levels. It also demonstrated a modest suppression of estradiol (>50 pg/ mL), which is consistent with the findings of other reports. During treatment, five patients experienced worsening anemia because of metrorrhagia, which is the most frequent adverse effect associated with dienogest. This report suggests that dienogest is an effective and well-tolerated therapy for symptomatic adenomyosis.

Whether hormonal contraceptives increase HIV-1 acquisition, transmission and disease progression are critical questions. Clinical research has been hampered by a lack of understanding that different progestins used in contraception exhibit differential off-target effects via steroid receptors other than the progesterone receptor. Of particular, relevance is the relative effects of medroxyprogesterone acetate (MPA) and norethisterone enanthate (NET-EN), widely used as injectable contraceptives in sub-Saharan Africa. While most high-quality clinical studies find no increased risk for HIV-1 acquisition with oral contraception or injectable NET-EN, most do find an increase with MPA, particularly in young women. Furthermore, mounting evidence from animal, ex vivo and biochemical studies are consistent with MPA acting to increase HIV-1 acquisition and pathogenesis, via mechanisms involving glucocorticoid-like effects on gene expression, in particular genes involved in immune function. We report that MPA, unlike NET and progesterone, represses inflammatory genes in human PBMCs in a dose-dependent manner, via the glucocorticoid receptor (GR), at concentrations within the physiologically relevant range. These and published results collectively suggest that the differential GR activity of MPA versus NET may be a mechanism whereby MPA, unlike NET or progesterone, differentially modulates HIV-1 acquisition and pathogenesis in target cells where the GR is the predominant steroid receptor expressed., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Prolactin controls the development and function of milk-producing breast epithelia but also supports growth and differentiation of breast cancer, especially luminal subtypes. A principal signaling mediator of prolactin, Stat5, promotes cellular differentiation of breast cancer cells in vitro, and loss of active Stat5 in tumors is associated with antiestrogen therapy failure in patients. In luminal breast cancer, progesterone induces a cytokeratin-5 (CK5)-positive basal cell-like population. This population possesses characteristics of tumor stem cells including quiescence, therapy resistance and tumor-initiating capacity. Here we report that prolactin counteracts induction of the CK5-positive population by the synthetic progestin (Pg) R5020 in luminal breast cancer cells both in vitro and in vivo. CK5-positive cells were chemoresistant as determined by fourfold reduced rate of apoptosis following docetaxel exposure. Pg-induction of CK5 was preceded by marked upregulation of BCL6, an oncogene and transcriptional repressor critical for the maintenance of leukemia-initiating cells. Knockdown of BCL6 prevented induction of CK5-positive cell population by Pg. Prolactin suppressed Pg-induced BCL6 through Jak2-Stat5 but not Erk- or Akt-dependent pathways. In premenopausal but not postmenopausal patients with hormone receptor-positive breast cancer, tumor protein levels of CK5 correlated positively with BCL6, and high BCL6 or CK5 protein levels were associated with unfavorable clinical outcome. Suppression of Pg-induction of CK5-positive cells represents a novel prodifferentiation effect of prolactin in breast cancer. The present progress may have direct implications for breast cancer progression and therapy as loss of prolactin receptor-Stat5 signaling occurs frequently and BCL6 inhibitors currently being evaluated for lymphomas may have value for breast cancer.

Progesterone and other progestagens are used in combination with estrogens for clinical purposes, including contraception and postmenopausal hormone therapy. Progesterone and estrogens have interactive effects in brain, however interactions between synthetic progestagens and 17β-estradiol (E2) in neurons are not well understood. In this study, we investigated the effects of seven clinically relevant progestagens on estrogen receptor (ER) mRNA expression, E2-induced neuroprotection, and E2-induced BDNF mRNA expression. We found that medroxyprogesterone acetate decreased both ERα and ERβ expression and blocked E2-mediated neuroprotection and BDNF expression. Conversely, levonorgestrel and nesterone increased ERα and or ERβ expression, were neuroprotective, and failed to attenuate E2-mediated increases in neuron survival and BDNF expression. Other progestagens tested, including norethindrone, norethindrone acetate, norethynodrel, and norgestimate, had variable effects on the measured endpoints. Our results demonstrate a range of qualitatively different actions of progestagens in cultured neurons, suggesting significant variability in the neural effects of clinically utilized progestagens., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Previous microarray analyses indicated that a portion of the transcriptome in the macaque corpus luteum (CL) of the menstrual cycle was regulated indirectly by luteinizing hormone via the local actions of steroid hormones, notably progesterone (P). The current study was designed to investigate this concept in the CL of early pregnancy by analyzing chorionic gonadotrophin (CG)-regulated genes that are dependent versus independent of local steroid action. Exogenous human chorionic gonadotropin treatment simulating early pregnancy (SEP) began on Day 9 of the luteal phase in female rhesus monkeys with and without concurrent administration of the 3-β-hydroxysteroid dehydrogenase inhibitor trilostane (TRL) with or without the synthetic progestin R5020. Compared with SEP treatment alone, TRL altered 50 mRNA transcripts on Day 10, rising to 95 on Day 15 (P<0.05, ≥2-fold change in gene expression). Steroid-sensitive genes were validated; notably effects of steroid ablation and P replacement varied by day. Expression of some genes previously identified as P-regulated in the macaque CL during the menstrual cycle were not significantly altered by steroid ablation and P replacement during CG exposure in SEP. These data indicate that the majority of CG-regulated luteal transcripts are differentially expressed independently of local steroid actions. However, the steroid-regulated genes in the macaque CL may be essential during early pregnancy, based on previous reports that TRL treatment initiates premature structural regression of the CL during SEP. These data reinforce the concept that the structure, function and regulation of the rescued CL in early pregnancy differs from the CL of the menstrual cycle in primates.

Hormone therapy may increase the risk of breast cancer. Thus, especially the addition of synthetic progestins may play a decisive role according to the results of clinical studies. Overexpression of a special receptor, i.e. the progesterone receptor membrane component-1 (PGRMC1), may offer a potential new pathway to explain the observed increase in breast cancer risk in the combined arm of the Women's Health Initiative. PGRMC1 is expressed in breast cancer tissue and may be important in tumorigenesis. The expression of PGRMC1 in breast cancer tissue is significantly different from that in normal mammary glands. Certain synthetic progestins can increase the proliferation of PGRMC1-overexpressing breast cancer cells and may thus be involved in tumorigenesis, while progesterone and certain synthetic progestins such as nomegestrol or chlormadinone acetate react neutrally. Our investigations point towards an important role of estrogen receptor-α in the signaling cascade, resulting in the proliferative effect induced by progestins. Thus, activation of PGRMC1 may explain the increased breast cancer risk observed during treatment with certain progestins. Very recently, PGRMC1 was investigated in serum samples of lung cancer patients and matched healthy patients; significantly higher concentrations were shown in the cancer patients. Therefore, PGRMC1 might be a predictor for other cancers as well but, according to clinical trials, its importance for a possible screening tool, particularly for breast cancer risk during hormone therapy, seems of interest.

Objective: To examine changes in lumbar spine-bone mineral density (LS-BMD) among normal weight (body mass index [BMI] = 18.5-24.9 kg/m(2)), Class 1-2 obese (BMI = 30-39.9 kg/m(2)), and Class 3 obese (BMI ≥ 40 kg/m(2)) women utilising depot-medroxyprogesterone acetate (DMPA)., Methods: Five normal-weight, five Class 1-2 obese, and five Class 3 obese women received subcutaneous injections of DMPA-SC at baseline and 12 weeks later. Dual Energy X-ray Absorptiometry (DEXA) scans were performed at baseline and 18 weeks after the first injection for determination of LS-BMD and analysis of fat content. Bimonthly oestradiol (E2) levels were measured by immunoassay methods for 26 weeks., Results: There were no significant demographic or LS-BMD differences among the three BMI groups. Significant differences at baseline were as expected among the three groups with respect to BMI and associated parameters (mean % total body fat, absolute fat, and weight). When used as their own controls, significant changes in LS-BMD, % body fat and absolute fat determined by DEXA occurred among all three BMI strata. Class 1-2 obese and Class 3 obese women were more likely to experience E2 fluctuations, but short-term changes in LS-BMD were similar., Conclusions: DMPA-SC administration affects L-spine bone health similarly regardless of BMI status.

Numerous studies aimed at identifying the role of estrogen on the brain have used the ovariectomized rodent as the experimental model. And while estrogen intervention in these animals has, at least partially, restored cholinergic, neurotrophin and cognitive deficits seen in the ovariectomized animal, it is worth considering that the removal of the ovaries results in the loss of not only circulating estrogen but of circulating progesterone as well. As such, the various deficits associated with ovariectomy may be attributed to the loss of progesterone as well. Similarly, one must also consider the fact that the human menopause results in the precipitous decline of not just circulating estrogens, but in circulating progesterone as well and as such, the increased risk for diseases such as Alzheimer's disease during the postmenopausal period could also be contributed by this loss of progesterone. In fact, progesterone has been shown to exert neuroprotective effects, both in cell models, animal models and in humans. Here, we review the evidence that supports the neuroprotective effects of progesterone and discuss the various mechanisms that are thought to mediate these protective effects. We also discuss the receptor pharmacology of progesterone's neuroprotective effects and present a conceptual model of progesterone action that supports the complementary effects of membrane-associated and classical intracellular progesterone receptors. In addition, we discuss fundamental differences in the neurobiology of progesterone and the clinically used, synthetic progestin, medroxyprogesterone acetate that may offer an explanation for the negative findings of the combined estrogen/progestin arm of the Women's Health Initiative-Memory Study (WHIMS) and suggest that the type of progestin used may dictate the outcome of either pre-clinical or clinical studies that addresses brain function., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Synthetic progestins (SPs) are used for regulation of fertility, contraception and hormone replacement therapy. The acetylated medroxyprogesterone (MPA), megestrol (MGA) and chlormadinone (CLA) are related to progesterone (P). Other SPs are 19-nortestosterone derivatives such as: norethisterone (NET), norethynodrel (NED) or the 13-ethyl gonane, levonorgestrel (LNG). We studied MPA, NET, NED and LNG in a dose-response manner to induce sexual receptivity in rats. Results showed that MPA, NET and NED act as partial agonists, with similar or lower potency than P. However, LNG is a full agonist. Additionally, the molecules of MPA, MGA, CLA, NET, NED, LNG, and P, were submitted to computer calculations at ab initio quantum mechanics theory, to obtain their electronic structure and molecular properties. The aim was to correlate their behavioral effect with their physicochemical properties. In addition, the crystals of P, NET and LNG bound to the progesterone receptor (PR) were studied. The PR crystallizes as a dimer forming two monomers (mA and mB), in which Gln725 interacts in either of two possible ways with the C3-carbonyl pharmacophore of progestins. P binds differentially to both PR monomers, while NET binds exclusively as mA and LNG binds only as mB in both monomers with no difference. Energetically, binding of LNG and P to mB, is more favorable than that of NET and P to mA. Consequently, this bimodal mechanism increases the action possibilities of SPs on biological systems. Interestingly, progestin potency depends mostly on local molecular structure and electronic features, prevailing over total molecular properties., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Background: Nomegestrol acetate (NOMAC), a synthetic progestogen derived from 19-nor-progesterone, recently completed clinical trials for use with 17beta-estradiol in a new monophasic combined oral contraceptive. In this review, published as well as previously unpublished preclinical studies that detail the effects of NOMAC on estrogenic, progestogenic, and androgenic systems, as well as mineralocorticoid, glucocorticoid, bone, and metabolic indices are described., Methods: In vitro assays to determine NOMAC structure-activity relationships used tissue derived from rat uteri. Transactivation profiles were performed using Chinese hamster ovary (CHO) cells transfected with cDNAs encoding human steroid receptors. Estrogenic and anti-estrogenic activities were monitored in vivo in rats as well as in vitro in human breast cancer cells. Standard in vivo techniques were used in rats to determine progestational activity; antigonadotropic, androgenic, mineralocorticoid, and glucocorticoid activities; as well as effects on bone and other metabolic indices. Ovulation inhibition was monitored in rats and primates. NOMAC's effects on cardiovascular systems were determined in dogs and primates., Results: NOMAC was without significant agonistic or antagonistic activity for estrogen receptor alpha or beta in vitro, and inhibited ovulation in rats and monkeys (2.5 mg/kg and 1 mg/kg, respectively). NOMAC lacked androgenic, antimineralocorticoid, glucocorticoid, and metabolic activity and exhibited moderate anti-androgenic activity in rats. NOMAC did not affect bone mineral density (BMD) in rats or hemodynamic and electrophysiologic parameters in dogs and primates., Conclusions: NOMAC is a selective progestogen structurally similar to progesterone that has modest anti-androgenic activity and does not affect lipid or carbohydrate metabolism, BMD, or many cardiovascular parameters in selected animal models.

Objectives: Evidence is accumulating that progestogens may play a crucial role in the development of breast cancer under contraception and hormone therapy in reproductive and menopausal women. Progesterone receptor membrane component 1 (PGRMC1) expressed in breast cancer may be important in tumorigenesis and thus may increase breast cancer risk. The aim of this project was to investigate the influence of progesterone and nine synthetic progestins on MCF-7 breast cancer cells overexpressing PGRMC1., Methods: MCF-7 cells were stably transfected with PGRMC1 expression plasmid (WT-12). To test the effects of progestogerone (P) and the synthetic progestins chlormadinone acetate (CMA), desogestrel (DSG), drospirenone (DRSP), dydrogesterone (DYD), levonorgestrel (LNG), medroxyprogesterone acetate (MPA), nomegestrol (NOM) and norethisterone (NET) on cell proliferation, MCF-7 and WT-12 cells were stimulated with different concentrations (0.01-1 µmol/l)., Results: In MCF-7 cells, DRSP, DSG, DYD, LNG and NET increased the proliferation at 1 µmol/l, the effect being highest for NET with about 20%. In WT-12 cells, the same progestins, but additionally MPA, showed a significant increase, which was much higher (30-245%) than in MCF-7 cells. Here again, NET showed the highest proliferative effect. No effect was found for CMA, NOM and P., Conclusion: Some synthetic progestins trigger a proliferative response of PGRMC1-overexpressed MCF-7 cancer cells. The effect of progestogens on breast cancer tumorigenesis may clearly depend on the specific pharmacology of the various synthetic progestins.

Recent clinical and epidemiological evidence shows that hormone replacement therapy (HRT) containing both estrogen and progestin increases the risk of primary and metastatic breast cancer in post-menopausal women while HRT containing only estrogen does not. We and others previously showed that progestins promote the growth of human breast cancer cells in vitro and in vivo. In this study, we sought to determine whether apigenin, a low molecular weight anti-carcinogenic flavonoid, inhibits the growth of aggressive Her2/neu-positive BT-474 xenograft tumors in nude mice exposed to medroxyprogesterone acetate (MPA), the most commonly used progestin in the USA. Our data clearly show that apigenin (50 mg/kg) inhibits progression and development of these xenograft tumors by inducing apoptosis, inhibiting cell proliferation, and reducing expression of Her2/neu. Moreover, apigenin reduced levels of vascular endothelial growth factor (VEGF) without altering blood vessel density, indicating that continued expression of VEGF may be required to promote tumor cell survival and maintain blood flow. While previous studies showed that MPA induces receptor activator of nuclear factor kappa-B ligand (RANKL) expression in rodent mammary gland, MPA reduced levels of RANKL in human tumor xenografts. RANKL levels remained suppressed in the presence of apigenin. Exposure of BT-474 cells to MPA in vitro also resulted in lower levels of RANKL; an effect that was independent of progesterone receptors since it occurred both in the presence and absence of the antiprogestin RU-486. In contrast to our in vivo observations, apigenin protected against MPA-dependent RANKL loss in vitro, suggesting that MPA and apigenin modulate RANKL levels differently in breast cancer cells in vivo and in vitro. These preclinical findings suggest that apigenin has potential as an agent for the treatment of progestin-dependent breast disease.

Synthetic progestins are used clinically to treat a variety of women's health issues. Although progestins are designed to signal through the progesterone receptor (PR) to elicit specific pharmacological effects, they can also variably bind to and influence the activity of other nuclear receptors within target tissues, particularly the androgen and glucocorticoid receptors and, in some cases, they regulate mineralocorticoid and estrogen receptors. This article reviews current knowledge on progestin cross-talk to nuclear receptors other than PR, their resultant effect on receptor function in different in vitro models and the potential consequences of this activity for breast, ovarian and endometrial cancer. The impact of cell and tissue context, assay type, steroid metabolism and hormonal milieu in determining progestin-mediated activity are also presented. Collectively this review highlights the complexity of progestin action and the need for consideration of multiple mechanisms that act in concert to influence their ultimate biological activity., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

The influence of progesterone in the brain and on the behavior of females is fairly well understood. However, less is known about the effect of progesterone in the male system. In male rats, receptors for progesterone are present in virtually all vasopressin (AVP) immunoreactive cells in the bed nucleus of the stria terminalis (BST) and the medial amygdala (MeA). This colocalization functions to regulate AVP expression, as progesterone and/or progestin receptors (PR)s suppress AVP expression in these same extrahypothalamic regions in the brain. These data suggest that progesterone may influence AVP-dependent behavior. While AVP is implicated in numerous behavioral and physiological functions in rodents, AVP appears essential for social recognition of conspecifics. Therefore, we examined the effects of progesterone on social recognition. We report that progesterone plays an important role in modulating social recognition in the male brain, as progesterone treatment leads to a significant impairment of social recognition in male rats. Moreover, progesterone appears to act on PRs to impair social recognition, as progesterone impairment of social recognition is blocked by a PR antagonist, RU-486. Social recognition is also impaired by a specific progestin agonist, R5020. Interestingly, we show that progesterone does not interfere with either general memory or olfactory processes, suggesting that progesterone seems critically important to social recognition memory. These data provide strong evidence that physiological levels of progesterone can have an important impact on social behavior in male rats., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Nomegestrol acetate (NOMAC) is a 19-norprogesterone derivative with high biological activity at the progesterone receptor, a weak anti-androgenic effect, but with no binding to estrogen, glucocorticoid or mineralocorticoid receptors. At dosages of 1.5mg/day or more, NOMAC effectively suppresses gonadotropic activity and ovulation in women of reproductive age. Hemostasis, lipids and carbohydrate metabolism remain largely unchanged. In normal and cancerous human breast cells, NOMAC has shown favorable effects on estrogen metabolism. Like natural progesterone (but in contrast to some other synthetic progestogens), it does not appear stimulate the proliferation of cancerous breast cells. While there has been some experience of the use of NOMAC in combination with estrogens as a hormone replacement therapy, most of the data on the compound are reported in the context of its inclusion as a component of a new contraceptive pill comprising 2.5mg NOMAC combined with 1.5mg estradiol. Because of its strong endometrial efficacy, and due to its high antigonadotropic activity and long elimination half-life (about 50h), the contraceptive efficacy of the new pill is maintained even when dosages are missed. Furthermore, for the first time with a monophasic 24/4 regimen containing estradiol, cyclical stability can be achieved comparable with that obtained using pills containing ethinyl estradiol and progestogens like levonorgestrel or drospirenone. The addition of NOMAC to estradiol means that the beneficial effects of estrogen are not lost, which is of especial importance in relation to the cardiovascular system. On the basis both of its pharmacology and of studies performed during the development of the NOMAC/estradiol pill, involving some 4000 women in total, good long-term tolerability can be expected for NOMAC, although its safety profile is still to be fully ascertained, as the clinical endpoint studies are yet to be completed., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

PFKFB (6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase) catalyses the synthesis and degradation of Fru-2,6-P2 (fructose-2,6-bisphosphate), a key modulator of glycolysis and gluconeogenesis. The PFKFB3 gene is extensively involved in cell proliferation owing to its key role in carbohydrate metabolism. In the present study we analyse its mechanism of regulation by progestins in breast cancer cells. We report that exposure of T47D cells to synthetic progestins (ORG2058 or norgestrel) leads to a rapid increase in Fru-2,6-P2 concentration. Our Western blot results are compatible with a short-term activation due to PFKFB3 isoenzyme phosphorylation and a long-term sustained action due to increased PFKFB3 protein levels. Transient transfection of T47D cells with deleted gene promoter constructs allowed us to identify a PRE (progesterone-response element) to which PR (progesterone receptor) binds and thus transactivates PFKFB3 gene transcription. PR expression in the PR-negative cell line MDA-MB-231 induces endogenous PFKFB3 expression in response to norgestrel. Direct binding of PR to the PRE box (-3490 nt) was confirmed by ChIP (chromatin immunoprecipiation) experiments. A dual mechanism affecting PFKFB3 protein and gene regulation operates in order to assure glycolysis in breast cancer cells. An immediate early response through the ERK (extracellular-signal-regulated kinase)/RSK (ribosomal S6 kinase) pathway leading to phosphorylation of PFKFB3 on Ser461 is followed by activation of mRNA transcription via cis-acting sequences on the PFKFB3 promoter.

Retinal degenerations such as Retinitis Pigmentosa remain difficult to treat given the diverse array of genes responsible for their aetiology. Rather than concentrate on specific genes, our focus is on identifying therapeutic avenues for the treatment of retinal disease that target general survival mechanisms or pathways. Norgestrel is a synthetic progestin commonly used in hormonal contraception. Here, we report a novel anti-apoptotic role for Norgestrel in diseased mouse retinas in vivo. Dosing with Norgestrel protects photoreceptor cells from undergoing apoptosis in two distinct models of retinal degeneration; the light damage model and the Pde6b(rd10) model. Photoreceptor rescue was assessed by analysis of cell number, structural integrity and function. Improvements in cell survival of up to 70% were achieved in both disease models, indicating that apoptosis had been halted or at least delayed. A speculative mechanism of action for Norgestrel involves activation of survival pathways in the retina. Indeed, Norgestrel increases the expression of basic fibroblast growth factor which is known to both promote cell survival and inhibit apoptosis. In summary, our results demonstrate significant protection of photoreceptor cells which may be attributed to Norgestrel mediated activation of endogenous survival pathways within the retina., (© 2011 The Authors. Journal of Neurochemistry © 2011 International Society for Neurochemistry.)

Background: Activity of nomegestrol acetate (NOMAC), levonorgestrel (LNG), drospirenone (DRSP), dienogest (DNG) and progesterone on human steroid receptor transactivation was investigated. Ovulation inhibition by NOMAC, LNG and progesterone was tested., Study Design: The progestogen receptor profile was determined in Chinese hamster ovary cells transfected with human progesterone B (PRB), androgen, estrogen (ER(α) and ER(β)), glucocorticoid (GR) and mineralocorticoid (MR) receptors, respectively. Ovulation inhibition was tested in rats and monkeys., Results: Agonistic potency rankings for PRB were LNG=NOMAC≫progesterone≫DRSP>DNG. No antagonistic activity at PRB was observed. Only LNG had androgenic activity. Antiandrogenic potency rankings were LNG≫NOMAC>progesterone>DNG>DRSP. All agents were devoid of activity at ER(α), ER(β) and GR. Only progesterone, DRSP and LNG had anti-MR activity. The NOMAC dose inhibiting ovulation at 50% ranged from 0.14 mg/kg (monkey) to 1.25 to 5.0 mg/kg (rat)., Conclusion: Nomegestrol acetate is a selective progestogen and a potent inhibitor of ovulation in the rat and monkey., (Copyright © 2011 Elsevier Inc. All rights reserved.)

A positive influence of altrenogest treatment on a retarded development of the conceptus around the beginning of placentation in mares older than 8 years could be recently demonstrated. In the present study, effects of altrenogest treatment in early-pregnant mares on conceptus development and expression of endometrial and embryonic genes were investigated. Genes were chosen according to a possible involvement in embryo-maternal interaction and embryonic development in the equine species. Mares were treated with altrenogest (0.044 mg/kg bodyweight) or sunflower oil (placebo) from day 5 to 11 after ovulation. Embryos (altrenogest n = 13, placebo n = 12) and biopsies were collected on day 11. Pregnancy rate and embryonic size were not influenced by treatment (embryonic diameter: altrenogest 7.0 ± 2.5, placebo 6.5 ± 1.7 mm, n.s.). The percentage of luminal epithelial cells, superficial glandular epithelial cells and interstitial cells with nuclei staining positively for the progesterone receptor was significantly lower (P < 0.05) in samples collected from altrenogest-treated than from placebo-treated mares (e.g., luminal epithelium: altrenogest 1.9 ± 1.7%, placebo 23.0 ± 10.5%, P < 0.05). Staining for COX2 (cyclooxygenase-2) was not affected by treatment. In the endometrium a slight but significant increase in the number of PMN (polymorph nuclear neutrophils) was seen in response to treatment (altrenogest 0.8 ± 0.5 PMN/field, placebo 0.3 ± 0.3 PMN/field; P < 0.05). No differences in the relative gene expression of COX2, the receptors for progesterone, estrogens and growth hormone as well as for IGF (insulin-like growth factor) 1 and 2 were detected. The relative gene expression of aquaporin 3 in relation to β-actin differed significantly (P < 0.05) between embryos from altrenogest (3.2 ± 0.8) and placebo-treated mares (1.3 ± 0.2), but no other genes were affected. The study demonstrates down-regulation of progesterone receptors in the endometrium of early pregnant mares by treatment with the progestin altrenogest. This increased expression of aquaporin 3 in the conceptus was not related to changes in embryonic size or development., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Synthetic progestins are used by millions of women as contraceptives and in hormone replacement therapy (HRT), although their molecular mechanisms of action are not well understood. The importance of investigating these mechanisms, as compared to those of progesterone, has been highlighted by clinical evidence showing that medroxyprogesterone acetate (MPA), a first generation progestin, increases the risk of breast cancer and coronary heart disease in HRT users. A diverse range of later generation progestins with varying structures and pharmacological properties is available for therapeutic use and it is becoming clear that different progestins elicit beneficial and adverse effects to different extents. These differences in biological activity are likely to be due to many factors including variations in dose, metabolism, pharmacokinetics, bioavailability, and regulation of, and/or binding, to serum-binding proteins and steroidogenic enzymes. Since the intracellular effects on gene expression and cell signaling of steroids are mediated via intracellular steroid receptors, differential actions via the progesterone and other steroid receptors and their isoforms, are likely to be the major cause of differential intracellular actions of progestins. Since many progestins bind not only to the progesterone receptor, but also to the glucocorticoid, androgen, mineralocorticoid, and possibly the estrogen receptors, it is plausible that synthetic progestins exert therapeutic actions as well as side-effects via some of these receptors. Here we review the molecular mechanisms of intracellular actions of old (MPA, norethisterone, levonorgestrel, gestodene) vs. new (drospirenone, dienogest, trimegestone) generation progestins, via steroid receptors., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Nomegestrol acetate (NOMAC) is a potent, highly selective progestogen, which is structurally similar to 19-norprogesterone and characterized as a full agonist at the progesterone receptor, with no or minimal binding to other steroid receptors, including the androgen and glucocorticoid receptors. In animal models, NOMAC demonstrated moderate antiandrogenic activity and strong antiestrogenic activity. In clinical studies, the progestogen was associated with effective suppression of gonadotropic activity and ovulation in premenopausal women, and a neutral impact on hemostasis, lipids, and carbohydrate metabolism. In normal and cancerous human breast tissue, NOMAC has shown favorable effects on estrogen metabolism, and in human breast cancer cell lines in vitro, it does not stimulate cell proliferation. The pharmacologic profile of NOMAC suggested that it would be well suited for combination with a physiologic estrogen in a combined oral contraceptive (COC), with the aim of achieving effective contraception with good cycle control and a favorable safety profile. A monophasic COC containing NOMAC 2.5mg and 17β-estradiol (E2) 1.5mg, administered in a 24/4-day regimen, is currently under clinical investigation. In a phase III study, NOMAC/E2 provided consistent and robust ovulation inhibition, with contraceptive effects that compared favorably with those of drospirenone 3mg/ethinyl estradiol (EE) 30 μg. Investigators for a second phase III study reported less overall impact with NOMAC/E2 on hemostatic, lipid, inflammatory, and carbohydrate metabolism parameters than with levonorgestrel 150 μg/EE 30 μg. These clinical findings are promising; however, full publication of results from the pivotal phase III trials of NOMAC/E2 is pending., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Progesterone (P4) exerts its effects by binding to specific genomic (nPR-A/B) and non-genomic (mPRalpha/beta, PGRMC1/2) receptors. P4 has a role in the regulation of the ovulatory cycle, but its participation in oocyte maturation in mammals has not yet been clarified. Therefore, the aim of the present study was to characterize the protein expression of P4 receptors (PRs) in bovine oocytes and cumulus cells during in vitro maturation (IVM) and to study the effect of P4 and its receptors on oocyte developmental competence. Cumulus-oocyte complexes (COCs) were subjected to IVM, in vitro fertilization, and in vitro culture. IVM was performed for 24 h in the presence or absence of P4, luteinizing hormone (LH), follicle-stimulating hormone (FSH), trilostane, promegestone (R5020), mifepristone (RU 486), or antibodies against mPRalpha or mPRbeta. Protein expression of PRs was studied by Western blotting and immunofluorescence. The results demonstrate the presence of both genomic and nongenomic PRs in bovine COCs. The dynamic changes observed in the protein expression of PRs following IVM or in response to supplementation with LH, FSH, or P4 suggest an important role during bovine oocyte maturation. Inhibition of P4 synthesis by cumulus cells or blocking of nPR and mPR alpha activity produced a decrease in bovine embryo development, indicating that P4 intracellular signaling is mediated by its interaction with nuclear and membrane PRs and is important for oocyte developmental competence.

Objectives: In healthy postmenopausal women (PMW) increased platelet activation has been associated with adverse cardiovascular events. There is much debate about the relationship between platelet function and serum estradiol level in PMW. This study assessed the effect of short-term oral estrogen replacement therapy (ERT) on platelet activation markers (CD62P and PAC-1) and its correlation with age and body mass index (BMI) among healthy PMW., Methods: A prospective intervention study was conducted at Hospital University Sains Malaysia, involving 48 healthy PMW who were evaluated for platelet activation marker levels as determined by flow cytometry, before and after two weeks of oral ERT with 0.625 mg of conjugated equine estrogen once daily. The pre- and post-ERT platelets activation markers difference was analysed by paired t-test., Results: The pre-ERT, mean ± SD percentage levels of CD62P and PAC-1 were significantly reduced from 7.00 ± 5.91 and 41.75 ± 26.85 to 3.05 ± 2.47 and 20.86 ± 19.02, respectively, after two weeks of ERT (P value < 0.001). The correlation of platelet activation markers was significant with estradiol but not with age and BMI., Conclusion: Short-term ERT leads to reduction in platelet activity, which might contribute to protection against cardiovascular diseases in healthy PMW.

Objective: To characterize skin wrinkles and rigidity in recently menopausal women., Design: Baseline assessment of participants before randomization to study drug., Setting: Multicenter trial, university medical centers., Patient(s): Recently menopausal participants enrolled in the Kronos Early Estrogen Prevention Study (KEEPS)., Intervention(s): Skin wrinkles were assessed at 11 locations on the face and neck using the Lemperle wrinkle scale. Skin rigidity was assessed at the forehead and cheek using a durometer., Main Outcome Measure(s): Skin wrinkles and rigidity were compared among race/ethnic groups. Skin wrinkles and rigidity were correlated with age, time since menopause, weight, and body mass index (BMI)., Result(s): In early menopausal women, wrinkles, but not skin rigidity, vary significantly among races, where black women have the lowest wrinkle scores. In white women, chronological age was significantly correlated with worsening skin wrinkles, but not with rigidity. Skin rigidity correlated with increasing length of time since menopause, however, only in the white subgroup. In the combined study group, increasing weight was associated with less skin wrinkling., Conclusion(s): Skin characteristics of recently menopausal women are not well studied. Ethnic differences in skin characteristics are widely accepted, but poorly described. In recently menopausal women not using hormone therapy (HT), significant racial differences in skin wrinkling and rigidity exist. Continued study of the KEEPS population will provide evidence of the effects of HT on the skin aging process in early menopausal women., (Copyright © 2011 American Society for Reproductive Medicine. All rights reserved.)

Research has established the principle of hormonal male contraception based on suppression of gonadotropins and spermatogenesis. All hormonal male contraceptives use testosterone, but only in East Asian men can testosterone alone suppress spermatogenesis to a level compatible with contraceptive protection. In Caucasians, additional agents are required of which progestins are favored. Clinical trials concentrate on testosterone combined with norethisterone, desogestrel, etonogestrel or depot-medroxyprogesterone acetate. The first randomized, placebo-controlled clinical trial performed by the pharmaceutical industry demonstrated the effectiveness of a combination of testosterone undecanoate and etonogestrel in suppressing spermatogenesis in volunteers., (Copyright © 2010 Elsevier Inc. All rights reserved.)

The synthetic progestins used for contraception so far are structurally related either to testosterone (estranes and gonanes) or to progesterone (pregnanes and 19-norpregnanes). Several new progestins have been designed to minimize side-effects related to androgenic, estrogenic or glucocorticoid receptor (GR) interactions. Dienogest (DNG) and drospirenone (DRSP) exhibit a partial antiandrogenic action, and DRSP has predominant anti-mineralocorticoid properties. The 19-norpregnanes include Nestorone (NES), nomegestrol acetate (NOMAc) and trimegestone (TMG), and possess a high specificity for binding to the progesterone receptor (PR) with no or little interaction with other steroid receptors. DRSP has been developed as combination oral pills with ethinyl estradiol (EE); DNG has been combined both with EE and, more recently, with estradiol valerate (E2V). NOMAc has been used as a progestin-only method and more recently combined with estradiol (E2). Nestorone is not active orally but proved to be the most active antiovulatory progestin when used parenterally. It has been developed in various formulations such as implants, vaginal rings or transdermal gel or spray. Risks and benefits of the new progestins depend upon the type of molecular structure, the type of estrogen associated in a combination and the route of administration., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Objective: The results of recent clinical trials indicate that hormone therapy with estrogen and progestin is associated with higher risk of breast cancer in postmenopausal women than treatment with estrogen alone or placebo. This observation is consistent with studies showing that progestins stimulate the expression of vascular endothelial growth factor (VEGF), which in turn stimulates angiogenesis. The objective of this study was to examine whether apigenin, a natural flavone, inhibits the progestin-dependent induction of VEGF in human breast cancer cells., Methods: T47-D human breast cancer cells were treated with medroxyprogesterone acetate (MPA; 10 nM) or other synthetic progestins in the presence or absence of antiprogestin RU-486 and variable doses of apigenin (1-100 microM). BT-474 cells were also treated with MPA +/- 100 microM apigenin. Secreted VEGF was quantified by enzyme-linked immunosorbent assay, and total cellular VEGF mRNA was quantified by reverse transcriptase polymerase chain reaction. The expression of VEGF receptor-1 (flt), VEGF receptor-2 (flk), progesterone receptor, and estrogen receptor-α was also quantified by Western blot analysis and/or reverse transcriptase polymerase chain reaction., Results: Apigenin (50 or 100 microM) prevented progestin-dependent induction of both VEGF mRNA and protein and reduced progesterone receptor levels in T47-D cells. Apigenin also blocked MPA-dependent secretion of VEGF from BT-474 cells. mRNA levels of progesterone and estrogen receptor-α were unaffected by apigenin, which did exert somewhat suppressive, although complex, effects on VEGF receptor expression in MPA-treated T47-D cells., Conclusions: Apigenin blocks progestin-dependent induction of VEGF mRNA and protein and broadly inhibits the ability of progestins to alter the expression of other components of the angiogenesis pathway, including progesterone receptor and VEGF receptors, in human breast cancer cells. Further studies are warranted to explore the potential of apigenin as a chemopreventive agent in postmenopausal women exposed to oral progestins.

Objective: Previous studies have shown that sequential exposure to estrogen and progesterone or medroxyprogesterone acetate (MPA) stimulates vascularization and promotes the progression of BT-474 and T47-D human breast cancer cell xenografts in nude mice (Liang et al, Cancer Res 2007, 67:9929). In this follow-up study, the effects of progesterone, MPA, norgestrel (N-EL), and norethindrone (N-ONE) on BT-474 xenograft tumors were compared in the context of several different hormonal environments. N-EL and N-ONE were included in the study because synthetic progestins vary considerably in their biological effects and the effects of these two progestins on the growth of human tumor xenografts are not known., Methods: Estradiol-supplemented intact and ovariectomized immunodeficient mice were implanted with BT-474 cells. Progestin pellets were implanted simultaneously with estradiol pellets either 2 days before tumor cell injection (ie, combined) or 5 days after tumor cell injections (ie, sequentially)., Results: Progestins stimulated the growth of BT-474 xenograft tumors independent of exposure timing and protocol, MPA stimulated the growth of BT-474 xenograft tumors in ovariectomized mice, and progestins stimulated vascular endothelial growth factor elaboration and increased tumor vascularity. Progestins also increased lymph node metastasis of BT-474 cells. Therefore, progestins, including N-EL and N-ONE, induce the progression of breast cancer xenografts in nude mice and promote tumor metastasis., Conclusions: These observations suggest that women who ingest progestins for hormone therapy or oral contraception could be more at risk for developing breast cancer because of proliferation of existing latent tumor cells. Such risks should be considered in the clinical setting.

Background: This randomized study's aim was to compare the effect of four oral contraceptives (OCs) containing 30 mcg of ethinylestradiol (EE) and different progestogens [drospirenone, (DRSP), chlormadinone acetate (CMA), desogestrel (DSG), gestodene (GSD)] on biochemical and hormonal parameters of hyperandrogenism and sex hormone-binding globulin (SHBG) in women with polycystic ovary syndrome (PCOS)., Study Design: Forty women with PCOS (age 16-35 years) were recruited and randomly assigned to one of four treatment groups of 10 women each, treated, respectively, with 3 mg DRSP/30 mcg EE (Yasmin, Bayer Shering), 2 mg CMA/30 mcg EE (Belara, Grunenthal), 75 mcg GSD/30 mcg EE (Minulet, Wyeth Lederle) and 150 mcg DSG/30 mcg EE (Practil 21, Organon Italia). Blood samples were obtained on day 6-8 of the control cycle and day 6-8 of the third treatment cycle for assay of the following hormones: androsteredione (A), total testosterone (T), free T, SHBG, dehydroepiandrosterone sulphate (DHEAS)., Results: In all groups, mean concentrations of free T, total T and A dropped by 40-60%, and concentrations of DHEAS dropped by 20-50%. Formulations with DRSP and CMA caused a greater reduction of androgens and a progressive increase in serum concentrations of SHBG than those with DSG and GSD., Conclusions: Clinical studies need to be performed to determine effects of these OCs upon clinical signs of hyperandrogenism., (Copyright 2010 Elsevier Inc. All rights reserved.)

Recent clinical trials show that combined oral dosing with estrogen and progestin increases the incidence of breast cancer in postmenopausal women. Similarly, in a rat model system of mammary carcinogenesis, the synthetic progestin medroxyprogesterone acetate (MPA) decreases latency and increases incidence of 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary tumors. The goal of this study was to compare the effects of four clinically relevant progestins, MPA, norgestrel (N-EL), norethindrone (N-ONE), and megestrol acetate (MGA), on DMBA-induced mammary carcinogenesis in the rat. The experimental protocol involved implantation of 60-day release progestin pellets four weeks after rats were treated with DMBA. In contrast to the effect of MPA, N-ONE, and N-EL, but not MGA, blocked DMBA-dependent carcinogenesis and a dose-dependent effect on tumor growth was shown for N-EL; MGA did not alter tumor growth. Histopathologic studies showed extensive hyperplastic lesions in mammary tissue of progestin-treated animals. Furthermore, following treatment with N-EL or N-ONE, immunohistochemical staining for vascular endothelial growth factor in hyperplastic mammary tissue was lower than in animals treated with DMBA plus MPA or DMBA alone. Expression of vascular endothelial growth factor receptor-1, estrogen receptor alpha, and progesterone receptor was also lower in hyperplastic mammary tissue in N-EL-, N-ONE-, and MGA-treated animals. Interestingly, N-EL stimulated progression of existing mammary tumors in DMBA/MPA-treated rats, suggesting stage-specific effects of N-EL in this model. Because N-EL and N-ONE prevent tumor growth in the early stages of DMBA-induced mammary carcinogenesis in rats, these progestins may have potential as chemopreventive agents in women with no history of breast disease or family history of breast cancer.

The age-related course of blood pressure and its gender-related difference, as well as the incidence of hypertension, have been the subject of multiple experimental, clinical and epidemiological studies over the past decades. The role of the sex hormones estradiol and testosterone within this gender dimorphism has been investigated without conclusive results. In this review, we provide background information on the gender difference in blood pressure, describe the impact of progesterone and aldosterone, and discuss the pathophysiology of aldosteronism as well as the potential role of drospirenone as a gender-specific agent for the prevention and treatment of hypertension and for cardiovascular protection.

Objective: Differences in disease outcomes between users and nonusers of hormone therapy (HT) and between users of estrogen therapy (ET) and users of estrogen + progesterone therapy (EPT) may relate to differences in serum hormone concentrations between these populations. In this study, we examined the response of serum hormone levels in healthy postmenopausal women after 1 year of HT., Methods: A representative subsample of 200 healthy adherent participants from the active and placebo groups of the Women's Health Initiative randomized controlled clinical trials of ET (conjugated equine estrogens 0.625 mg daily) or EPT (ET plus medroxyprogesterone acetate 2.5 mg daily) were selected for the determination of selected sex hormone levels at baseline and 1 year after randomization., Results: In participants receiving active ET intervention compared with placebo, estrogenic hormone levels increased from baseline to year 1 by 3.6-fold for total estrone, 2.7-fold for total estradiol, and 1.8-fold for bioavailable and free estradiol concentrations. Serum sex hormone-binding globulin concentrations also increased 2.5-fold. In contrast, progesterone levels decreased slightly in women taking exogenous EPT. The response of serum estrogens and sex hormone-binding globulin did not differ substantially with the addition of progesterone. In subgroup analyses, hormone response varied by age, ethnicity, body mass index, smoking status, vasomotor symptoms, and baseline hormone levels., Conclusions: These data provide a reference point for the serum hormone response to HT and demonstrate that the response of serum estrogens is similar for ET and EPT. The implications of the slight decrease in serum progesterone levels with EPT therapy are uncertain. Potential treatment interactions for estrogenic hormones were identified, which suggest a larger response to HT in women with low endogenous levels.