Effect of oestrogen modulation on semen parameters in men with secondary hypogonadism: Systematic review and meta-analysis

BACKGROUND

Selective oestrogen receptor modulators and aromatase inhibitors stimulate endogenous gonadotrophins and testosterone in men with hypogonadism. There are no systematic reviews/meta-analyses assessing the effects of selective oestrogen receptor modulators/aromatase inhibitors on semen parameters in men with secondary hypogonadism.

OBJECTIVES

To assess the effect of monotherapy or a combination of selective oestrogen receptor modulators/aromatase inhibitors on sperm parameters and/or fertility in men with secondary hypogonadism.

MATERIALS AND METHODS

A systematic search was conducted in PubMed, MEDLINE, Cochrane Library and ClinicalTrials.gov. Study selection and data extraction were performed by two reviewers independently. Randomised controlled trials and non-randomised studies of interventions reporting effects of selective oestrogen receptor modulators and/or aromatase inhibitors on semen parameters or fertility in men with low testosterone with low/normal gonadotrophins were selected. The risk of bias was assessed using ROB-2 and ROBINS-I tools. The results of randomised controlled trials were summarised using vote counting while summarising effect estimates where available. Non-randomised studies of intervention meta-analysis were conducted using the random-effect model. The certainty of evidence was assessed using GRADE.

RESULTS

Five non-randomised studies of interventions (n = 105) of selective oestrogen receptor modulators showed an increase in sperm concentration (pooled mean difference 6.64 million/mL; 95% confidence interval 1.54, 11.74, I2  = 0%) and three non-randomised studies of interventions (n = 83) of selective oestrogen receptor modulators showed an increase in total motile sperm count (pooled mean difference 10.52; 95% confidence interval 1.46-19.59, I2  = 0%), with very low certainty of evidence. The mean body mass index of participants was >30 kg/m2 . Four randomised controlled trials (n = 591) comparing selective oestrogen receptor modulators to placebo showed a heterogeneous effect on sperm concentration. Three included men with overweight or obesity. The results were of very low certainty of evidence. Limited pregnancy or live birth data were available. No studies comparing aromatase inhibitors with placebo or testosterone were found.

DISCUSSION AND CONCLUSION

Current studies are of limited size and quality but suggest that selective oestrogen receptor modulators may improve semen parameters in those patients, particularly when associated with obesity.

SERM Therapy for patients of breast cancer and otherwise

Madam, In Pakistan, the most frequently diagnosed cancer among females is breast cancer, where every year at least 90,000 women suffer from the disease [1]. This incidence is 2.5 times higher than that of Pakistan’s neighbouring countries and the highest in Asia[1]. The current treatments for breast cancer in the country are all invasive forms of therapy and include radiation therapy, chemotherapy, lymph node removal, and mastectomy. This letter aims to draw attention to a newer form of treatment for breast cancer known as selective estrogen receptor modulators (SERMs). Selective estrogen receptor modulators (SERMs) are synthetic molecules that provide a non-invasive therapy for breast cancer patients. Recent studies have proposed that the specificity of SERM’s mechanism of action and antiviral properties yield fruitful outcomes in treating covid-positive breast cancer patients [2], giving SERMs a significant advantage over former treatments such as radiation therapy or chemotherapy which reduce the body’s ability to fight infections. SERMs block the effects of estrogen on breast tissue, preventing cancer cells from dividing. They also act as an adjuvant in breast cancer therapy [3], suppressing secondary tumor formation. A recent study published in the Journal of Clinical Oncology showed significant benefits from two years of tamoxifen therapy in estrogen receptor- positive premenopausal patients of breast cancer [4].  On various other tissues, they act as estrogen, allowing for their use alongside other treatments for postmenopausal women to prevent bone loss and osteoporosis [3]. Despite SERM ‘s wide range of benefits in patients with breast cancer, it is not a fully recognized form of treatment for this population in Pakistan. Such hormonal therapy is only offered by a handful of high-end private-sector hospitals. This is attributed to a lack of research in this area due to various socio-economic factors. A limited choice of treatment for women with breast cancer in Pakistan results from fear of stigmatization and feminine sensitivity [5]. Attention should be brought to alternative therapies for breast cancer treatment to improve prognosis and help patients make the best possible shared decision-making choices.

Romosozumab is associated with greater trabecular bone score improvement compared to denosumab in postmenopausal osteoporosis

In this study, romosozumab demonstrated significantly greater improvement in trabecular bone score compared to denosumab therapy in postmenopausal women previously treated with antiresorptive agents. Notably, in patients previously treated with anti-resorptive agents, treatment with romosozumab resulted in similar increases in trabecular bone score compared to that of drug-naïve patients.

PURPOSE

Romosozumab significantly increases bone mineral density (BMD) and rapidly reduces fracture risk. Whether romosozumab can improve the spinal trabecular bone score (TBS) as a bone quality indicator merits further investigation.

METHODS

Data for postmenopausal women starting romosozumab or denosumab treatment at Severance Hospital, Korea, were analyzed. Romosozumab and denosumab groups were 1:1 matched using propensity scores, considering relevant covariates. Good responders were defined as those with TBS improvement of 5.8% or greater.

RESULTS

Overall, 174 patients (romosozumab, n = 87; denosumab, n = 87) were analyzed. Matched groups did not differ in age (64 years), weight, height, previous fracture (38%), lumbar spine or femoral neck BMD (T-score, -3.4 and -2.6, respectively), or prior bisphosphonate or selective estrogen receptor modulator (SERM) exposure (50%). The romosozumab group exhibited a greater increase in lumbar spine BMD (15.2% vs. 6.9%, p < 0.001) and TBS (3.7% vs. 1.7%, p = 0.013) than the denosumab group. In patients transitioning from bisphosphonate or SERM, romosozumab users showed greater improvement in TBS compared to denosumab users (3.9% versus 0.8%, P = 0.006); the drug-naive group showed no significant difference (3.6% versus 2.7%, P = 0.472). The romosozumab group had a higher proportion of good responders than the denosumab group (33.3% vs. 18.4%, p = 0.024). Romosozumab therapy for 12 months resulted in 3.8-fold higher odds of a good response in TBS than denosumab after covariate adjustment (adjusted odds ratio 3.85, p = 0.002).

CONCLUSION

Romosozumab could improve bone mass and bone quality, measured by TBS, in postmenopausal osteoporosis, particularly as a subsequent regimen in patients previously taking anti-resorptive agents.

A high-resolution α-glucosidase inhibition profiling for targeted identification of natural antidiabetic products from Lycopodiella cernua (L.) Pic. Serm and their inhibitory mechanism study

The targeted identification of α-glucosidase inhibitors from the crude ethyl acetate of Lycopodiella cernua (L.) Pic. Serm (L.cernua) was guided by high-resolution inhibition profiling. The α-glucosidase inhibition profiling and HPLC-QTOF-MS showed tannins and serratenes were the corresponding antidiabetic constituents. Two new serratenes named 3β, 21β-dihydroxyserra-14-en-24-oic acid-3β-(4'-methoxy-5'-hydroxybenzoate) (4), 3β, 21α-dihydroxyserra-14-en-24-oic acid-3β-(4'-methoxy-5'-hydroxybenzoate) (7), together with two known compounds (5 and 6) were isolated. Their structures were elucidated by HR-ESI-MS and NMR. Compounds 5-7 inhibited the α-glucosidase activity in a non-competitive manner with Ki values ranging from 1.29 to 12.9 µM. The molecular docking result unveiled that 4-7 bound to the residues at the channel site, which enabled to block the substrate access. In addition, the molecular dynamics (MD) simulation of the most active compound 7 and α-glucosidase indicated the 4'-methoxy-5'-hydroxybenzoate group formed the stable hydrogen bonds and pi-pi T-shaped interactions with Arg312, Gln350 and Phe300 residues, while the rings D and E were stabilized by hydrophobic interaction.

Drug utilization analysis of osteoporosis medications in seven European electronic health databases

We studied the characteristics of patients prescribed osteoporosis medication and patterns of use in European databases. Patients were mostly female, older, had hypertension. There was suboptimal persistence particularly for oral medications. Our findings would be useful to healthcare providers to focus their resources on improving persistence to specific osteoporosis treatments.

PURPOSE

To characterise the patients prescribed osteoporosis therapy and describe the drug utilization patterns.

METHODS

We investigated the treatment patterns of bisphosphonates, denosumab, teriparatide, and selective estrogen receptor modulators (SERMs) in seven European databases in the United Kingdom, Italy, the Netherlands, Denmark, Spain, and Germany. In this cohort study, we included adults aged ≥ 18 years, with ≥ 1 year of registration in the respective databases, who were new users of the osteoporosis medications. The study period was between 01 January 2018 to 31 January 2022.

RESULTS

Overall, patients were most commonly initiated on alendronate. Persistence decreased over time across all medications and databases, ranging from 52-73% at 6 months to 29-53% at 12 months for alendronate. For other oral bisphosphonates, the proportion of persistent users was 50-66% at 6 months and decreased to 30-44% at 12 months. For SERMs, the proportion of persistent users at 6 months was 40-73% and decreased to 25-59% at 12 months. For parenteral treatment groups, the proportions of persistence with denosumab were 50-85% (6 month), 30-63% (12 month) and with teriparatide 40-75% (6 month) decreasing to 21-54% (12 month). Switching occurred most frequently in the alendronate group (2.8-5.8%) and in the teriparatide group (7.1-14%). Switching typically occurred in the first 6 months and decreased over time. Patients in the alendronate group most often switched to other oral or intravenous bisphosphonates and denosumab.

CONCLUSION

Our results show suboptimal persistence to medications that varied across different databases and treatment switching was relatively rare.

Hormone therapy for sexual function in perimenopausal and postmenopausal women

BACKGROUND

The perimenopausal and postmenopausal periods are associated with many symptoms, including sexual complaints. This review is an update of a review first published in 2013.

OBJECTIVES

We aimed to assess the effect of hormone therapy on sexual function in perimenopausal and postmenopausal women.

SEARCH METHODS

On 19 December 2022 we searched the Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, LILACS, ISI Web of Science, two trials registries, and OpenGrey, together with reference checking and contact with experts in the field for any additional studies.

SELECTION CRITERIA

We included randomized controlled trials that compared hormone therapy to either placebo or no intervention (control) using any validated assessment tool to evaluate sexual function. We considered hormone therapy: estrogen alone; estrogen in combination with progestogens; synthetic steroids, for example, tibolone; selective estrogen receptor modulators (SERMs), for example, raloxifene, bazedoxifene; and SERMs in combination with estrogen.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. We analyzed data using mean differences (MDs) and standardized mean differences (SMDs). The primary outcome was the sexual function score. Secondary outcomes were the domains of sexual response: desire; arousal; lubrication; orgasm; satisfaction; and pain. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 36 studies (23,299 women; 12,225 intervention group; 11,074 control group), of which 35 evaluated postmenopausal women; only one study evaluated perimenopausal women. The 'symptomatic or early postmenopausal women' subgroup included 10 studies, which included women experiencing menopausal symptoms (symptoms such as hot flushes, night sweats, sleep disturbance, vaginal atrophy, and dyspareunia) or early postmenopausal women (within five years after menopause). The 'unselected postmenopausal women' subgroup included 26 studies, which included women regardless of menopausal symptoms and women whose last menstrual period was more than five years earlier. No study included only women with sexual dysfunction and only seven studies evaluated sexual function as a primary outcome. We deemed 20 studies at high risk of bias, two studies at low risk, and the other 14 studies at unclear risk of bias. Nineteen studies received commercial funding. Estrogen alone versus control probably slightly improves the sexual function composite score in symptomatic or early postmenopausal women (SMD 0.50, 95% confidence interval (CI) (0.04 to 0.96; I² = 88%; 3 studies, 699 women; moderate-quality evidence), and probably makes little or no difference to the sexual function composite score in unselected postmenopausal women (SMD 0.64, 95% CI -0.12 to 1.41; I² = 94%; 6 studies, 608 women; moderate-quality evidence). The pooled result suggests that estrogen alone versus placebo or no intervention probably slightly improves sexual function composite score (SMD 0.60, 95% CI 0.16 to 1.04; I² = 92%; 9 studies, 1307 women, moderate-quality evidence). We are uncertain of the effect of estrogen combined with progestogens versus placebo or no intervention on the sexual function composite score in unselected postmenopausal women (MD 0.08 95% CI -1.52 to 1.68; 1 study, 104 women; very low-quality evidence). We are uncertain of the effect of synthetic steroids versus control on the sexual function composite score in symptomatic or early postmenopausal women (SMD 1.32, 95% CI 1.18 to 1.47; 1 study, 883 women; very low-quality evidence) and of their effect in unselected postmenopausal women (SMD 0.46, 95% CI 0.07 to 0.85; 1 study, 105 women; very low-quality evidence). We are uncertain of the effect of SERMs versus control on the sexual function composite score in symptomatic or early postmenopausal women (MD -1.00, 95% CI -2.00 to -0.00; 1 study, 215 women; very low-quality evidence) and of their effect in unselected postmenopausal women (MD 2.24, 95% 1.37 to 3.11 2 studies, 1525 women, I² = 1%, low-quality evidence). We are uncertain of the effect of SERMs combined with estrogen versus control on the sexual function composite score in symptomatic or early postmenopausal women (SMD 0.22, 95% CI 0.00 to 0.43; 1 study, 542 women; very low-quality evidence) and of their effect in unselected postmenopausal women (SMD 2.79, 95% CI 2.41 to 3.18; 1 study, 272 women; very low-quality evidence). The observed heterogeneity in many analyses may be caused by variations in the interventions and doses used, and by different tools used for assessment.

AUTHORS' CONCLUSIONS

Hormone therapy treatment with estrogen alone probably slightly improves the sexual function composite score in women with menopausal symptoms or in early postmenopause (within five years of amenorrhoea), and in unselected postmenopausal women, especially in the lubrication, pain, and satisfaction domains. We are uncertain whether estrogen combined with progestogens improves the sexual function composite score in unselected postmenopausal women. Evidence regarding other hormone therapies (synthetic steroids and SERMs) is of very low quality and we are uncertain of their effect on sexual function. The current evidence does not suggest the beneficial effects of synthetic steroids (for example tibolone) or SERMs alone or combined with estrogen on sexual function. More studies that evaluate the effect of estrogen combined with progestogens, synthetic steroids, SERMs, and SERMs combined with estrogen would improve the quality of the evidence for the effect of these treatments on sexual function in perimenopausal and postmenopausal women.

The comparable efficacy of denosumab on bone mineral density in rheumatoid arthritis patients with postmenopausal osteoporosis: A retrospective case-control study

Little is known about differences in the therapeutic efficacy of denosumab in subjects with and without rheumatoid arthritis (RA). This study compares the changes in bone mineral density (BMD) between RA patients and controls without RA who had been treated with denosumab for 2 years for postmenopausal osteoporosis. A total of 82 RA patients and 64 controls were enrolled, who were refractory to selective estrogen receptor modulators (SERMs) or bisphosphonates and completed the treatment of denosumab 60 mg for 2 years. The efficacy of denosumab in RA patients and controls was assessed using areal BMD (aBMD) and T-score of the lumbar spine, femur neck, and total hip. A general linear model with repeated measures analysis of variance was used to determine differences in aBMD and T-score between 2 study groups. No significant differences in percent changes in aBMD and T-scores by denosumab treatment for 2 years at the lumbar spine, femur neck, and total hip were evident between RA patients and controls (P > .05 of all), except T-score of the total hip (P = .034). Denosumab treatment equally increased aBMD at the lumbar spine and T-scores at the lumbar spine and total hip between RA patients and controls without statistical differences, but RA patients showed less improvement in aBMD at the femur neck (ptime*group = 0.032) and T-scores at the femur neck and total hip than controls (ptime*group = 0.004 of both). Changes in aBMD and T-scores after denosumab treatment in RA patients were not affected by previous use of bisphosphonates or SERMs. Differences of T-score at the femur neck among previous bisphosphonate users and aBMD and T-score at the femur neck and T-scores at the total hip were evident. This study revealed that 2 years of denosumab treatment in female RA patients achieved comparable efficacy on BMD to controls at the lumbar spine, but showed somewhat insufficient improvement at the femur neck and total hip.

Meta-analysis of placebo-arm dropouts in osteoporosis randomized-controlled trials and implications for nocebo-associated discontinuation of anti-osteoporotic drugs in clinical practice

Dropout from placebo arms in randomized-controlled trials is a surrogate for nocebo responses, resulting from patients' negative expectations to treatment. Among 16,460 placebo-treated patients in oral anti-osteoporotic drug trials, nocebo dropouts were 8% on average, being higher in older patients. This implies that nocebo may contribute to the osteoporosis treatment gap in clinical practice.

PURPOSE

Osteoporosis is a common disease requiring long-term treatment. Despite the availability of effective anti-osteoporotic drugs, adherence to treatment is low. Nocebo, a behavior mostly related to the negative expectations to a certain treatment, decreases adherence and negatively affects treatment outcomes and health-related care costs in chronic diseases. Since in double-blind placebo-controlled randomized trials any unfavorable outcome leading to discontinuation in placebo arms is considered as nocebo, we aimed to investigate the size of nocebo response in patients participating in osteoporosis trials.

METHODS

We searched MEDLINE, EMBASE, SCOPUS, and Cochrane databases for dropouts due to reported adverse events in the placebo arms (nocebo dropouts) in all double-blind trials investigating anti-osteoporotic drugs published between January 1993 and March 2022. Only data on bisphosphonates and selective estrogen receptor modulators (SERMs) were analyzed (Prospero registration number CRD42020212843).

RESULTS

Data from 44 trials were extracted. In 16,460 placebo-treated patients, the pooled nocebo-dropout was 8% both for bisphosphonates (average: 0.08; range 0.01-0.27; 95%CI 0.06-0.10) and SERMs (average: 0.08; range 0.03-0.15; 95%CI 0.05-0.13). Nocebo-dropouts were higher in bisphosphonate trials enrolling individuals ≥ 65 years (11%) (n = 18) compared to trials enrolling younger individuals (6%) (n = 18) (average: 0.11; 95%CI 0.08-0.13 vs. average: 0.06; 95%CI 0.05-0.08, respectively, p = 0.001). Participants' sex, dosing-intervals, publication year, or severity of osteoporosis had no impact on the nocebo-dropouts.

CONCLUSION

Almost 1 in 10 osteoporosis patients receiving placebo in trials of bisphosphonates and SERMs experiences AEs leading to dropout, implying that nocebo contributes to treatment-discontinuation in clinical practice. Efforts to identify and minimize nocebo, especially in older patients, are warranted.

Optical Detection and Imaging of Nonfluorescent Matter at the Single-Molecule/Particle Level

Since the first optical detection of single molecules in 1989, single-molecule spectroscopy has developed rapidly and been widely applied in many areas. However, the vast majority of matter is extremely inefficient at emitting photons in our physical world, which seriously limits the applications of optical methods based on photoluminescence. In addition to indirect detection by fluorescence labeling, many efforts have been made to directly image nonfluorescent matter at the single-particle or single-molecule level in different ways based on the absorption or scattering interaction between light and matter. Herein, we review five popular methods for imaging nonfluorescent particles/molecules, including dark-field microscopy (DFM), surface plasmon resonance microscopy (SPRM), surface enhanced Raman microscopy (SERM), interferometric scattering microscopy (iSCAT), and photothermal microscopy (PTM). After summarizing the principles and applications of these methods, we compare the advantages and disadvantages of each method and describe further potential development and applications.

Resveratrol Analogues as Selective Estrogen Signaling Pathway Modulators: Structure–Activity Relationship

Resveratrol is a plant-derived phytoalexin found in grapes, red wine and many other plants used in Asian folk medicine. It is extensively studied for pleiotropic biological activity. The most crucial are anticancer and chemopreventive properties. Resveratrol has also been reported to be an antioxidant and phytoestrogen. The phytoestrogenic activity of resveratrol was assayed in different in vitro and in vivo models. Although these works brought some, on the first look, conflicting results, it is commonly accepted that resveratrol interacts with estrogen receptors and functions as a mixed agonist/antagonist. It is widely accepted that the hydroxyl groups are crucial for resveratrol’s cytotoxic and antioxidative activity and are responsible for binding estrogen receptors. In this work, we assayed 11 resveratrol analogues, seven barring methoxy groups and six hydroxylated analogues in different combinations at positions 3, 4, 5 and 3′,4′,5′. For this purpose, recombined estrogen receptors and estrogen-dependent MCF-7 and Ishikawa cells were used. Our study was supported by in silico docking studies. We have shown that, resveratrol and 3,4,4′5′-tetrahydroxystilbene, 3,3′,4,5,5′-pentahydroxystilbene and 3,3′,4,4′,5,5′-hexahydroxystilbene may act as selective estrogen receptor modulators.

Low serm Fibroblast Growth Factor-21 levels is not associated with Carotid intima-media thickness in acromegaly patients

INTRODUCTION

Elevated fibroblast growth factor-21 (FGF-21) levels are related to carotid intima-media thickness (CIMT), a well-established marker of atherosclerosis. Acromegaly has also been linked to increased CIMT. There has been no data considering the association between FGF-21 levels and atherosclerosis in acromegaly patients. This study aimed to evaluate FGF-21 levels and CIMT in acromegalic patients in relation to atherosclerotic complications.

DESIGN

Case-control study.

MATERIALS AND METHODS

The study group included 70 acromegaly patients and 72 healthy volunteers from the Department of Endocrinology and Metabolism Disease, Marmara University Medical School. FGF-21, growth hormone, insulin-like growth factor I, lipids, glucose, insulin levels were assessed. CIMT was measured from the common carotid artery wall on B-mode ultrasound.

RESULTS

Median FGF-21 levels were significantly lower in the acromegaly group than in the control group. CIMT was higher in acromegaly patients compared to controls. Although there was no correlation between FGF-21 levels and CIMT in patients with acromegaly, a positive correlation was found between high-density lipoprotein-cholesterol and FGF-21 levels. Glucose metabolic markers were the determining factors of the FGF-21 levels in acromegaly patients.

CONCLUSION

Our study is the first to examine the relationship between serum FGF-21 levels and atherosclerosis in acromegaly patients. The lower serum FGF-21 levels in acromegaly subjects might be associated with the improving effects of growth hormone on liver fat. Acromegaly was linked to higher CIMT, but there was no correlation between FGF-21 levels and CIMT. The role of FGF-21 in acromegaly as a marker of atherosclerosis requires additional research.

Are SERMs safe and effective for the treatment of hypogonadism in men?

YES. For both normal-weight and obese men with low testosterone levels and hypogonadal symptoms, selective estrogen receptor modulators (SERMs), such as clomiphene citrate (CC) and enclomiphene citrate (EC), appear to be effective and safe for improving serum testosterone levels (strength of recommendation [SOR]: C, disease-oriented outcomes from randomized controlled trials [RCTs] and cohort studies). Studies also show that symptom improvement is comparable to that with exogenous testosterone replacement and similar to eugonadal men (SOR: B, patient-oriented outcomes from retrospective cohort studies).

Comparison of dyslipidemia incidence in Chinese early-stage breast cancer patients following different endocrine therapies: A population-based cohort study

BACKGROUND

There is lack of large-scale real-world research evidence showing the impact of endocrine therapy on blood lipids in Chinese breast cancer patients, especially those with premenopausal breast cancer. Based on a large breast cancer cohort at West China Hospital, we aimed to compare the risk of dyslipidemia between premenopausal and postmenopausal women based on the endocrine therapy used.

METHODS

A total of 1,883 early-stage breast cancer (EBC) patients who received endocrine monotherapy [selective estrogen receptor modulator (SERM) and aromatase inhibitor (AI), with or without ovarian function suppression] with normal blood lipid levels at baseline were retrospectively included between October 2008 and April 2017. Dyslipidemia was defined as an abnormality in cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein, and total cholesterol (TC) levels. The risk accumulation function was used to calculate the incidence of dyslipidemia in order to assess the absolute risk, while the multivariate Cox regression model was used to calculate the relative risk of dyslipidemia between the groups.

RESULTS

Patients with EBC were followed up for 60 months to monitor their blood lipid levels. The accumulated 5-year incidence of dyslipidemia in postmenopausal patients was higher than that in premenopausal patients (adjusted HR [95% confidence interval], 1.25 [1.01-1.56], 41.7% vs. 31.2%, p = 0.045). In premenopausal patients, the risk of abnormal TC was significantly higher in the OFS+AI group compared with that in the SERM group (adjusted HR [95% CI], 6.24 [3.19-12.20], p < 0.001, 5-year abnormal rates: 21.5% vs. 2.4%), and that of abnormal LDL-C level also increased (adjusted HR [95% CI], 10.54 [3.86-28.77], p < 0.001, 5-year abnormal rates: 11.1% vs. 0.9%). In postmenopausal patients, the risk of abnormal TC or LDL-C levels showed a similar trend in the AI and SERM groups.

CONCLUSIONS

In addition to postmenopausal patients, dyslipidemia is also common in premenopausal Chinese patients with EBC who received endocrine therapy. Irrespective of menopausal status, AI treatment increases the risk of TC/LDL-C dyslipidemia than SERM treatment.

The physiological role of estrogen receptor functional domains

Estrogen receptor (ER) is a member of the nuclear receptor superfamily whose members share conserved domain structures, including a DNA-binding domain (DBD) and ligand-binding domain (LBD). Estrogenic chemicals work as ligands for activation or repression of ER-mediated transcriptional activity derived from two transactivation domains: AF-1 and AF-2. AF-2 is localized in the LBD, and helix 12 of the LBD is essential for controlling AF-2 functionality. The positioning of helix 12 defines the ER alpha (ERα) ligand properties as agonists or antagonists. In contrast, it is still less well defined as to the ligand-dependent regulation of N-terminal AF-1 activity. It has been thought that the action of selective estrogen receptor modulators (SERMs) is mediated by the regulation of a tissue specific AF-1 activity rather than AF-2 activity. However, it is still unclear how SERMs regulate AF-1 activity in a tissue-selective manner. This review presents some recent observations toward information of ERα mediated SERM actions related to the ERα domain functionality, focusing on the following topics. (1) The F-domain, which is connected to helix 12, controls 4-hydroxytamoxifen (4OHT) mediated AF-1 activation associated with the receptor dimerization activity. (2) The zinc-finger property of the DBD for genomic sequence recognition. (3) The novel estrogen responsive genomic DNA element, which contains multiple long-spaced direct-repeats without a palindromic ERE sequence, is differentially recognized by 4OHT and E2 ligand bound ERα transactivation complexes.

Persistent Metabolic Effects of Tamoxifen: Considerations for an Experimental Tool and Clinical Breast Cancer Treatment

The selective estrogen receptor (ER) modulator tamoxifen is frequently used in preclinical studies to induce Cre recombinase and generate conditional transgenic mice. In addition, it is often prescribed to treat ER-positive breast cancer, which is diagnosed in approximately 150 000 people each year. In mice, protocols to activate Cre-ER transgenes require tamoxifen administration by several methods, including oral gavage, IP injection, or intragastric injection, spanning a wide range of doses to achieve transgene induction. As a result, the reported metabolic effects of tamoxifen treatment are not always consistent with anecdotal reports from breast cancer patients, or with expected outcomes based on the overall metabolically protective role of estrogen. A greater awareness of tamoxifen's adverse metabolic effects is critical to designing studies with appropriate controls, especially those investigations focused on metabolic outcomes.

ZNF423 modulates the AMP-activated protein kinase pathway and metformin response in a single nucleotide polymorphisms, estrogen and selective estrogen receptor modulator dependent fashion

OBJECTIVES

We previously discovered that the single nucleotide polymorphisms (SNP) rs9940645 in the ZNF423 gene regulate ZNF423 expression and serve as a potential biomarker for response to selective estrogen receptor modulators (SERMs). Here we explored pathways involved in ZNF423-mediated SERMs response and drugs that potentially sensitize SERMs.

METHODS

RNA sequencing and label-free quantitative proteomics were performed to identify genes and pathways that are regulated by ZNF423 and the ZNF423 SNP. Both cultured cells and mouse xenograft models with different ZNF423 SNP genotypes were used to study the cellular responses to metformin.

RESULTS

We identified ribosome and AMP-activated protein kinase (AMPK) signaling as potential pathways regulated by ZNF423 or ZNF423 rs9940645 SNP. Moreover, using clustered regularly interspaced short palindromic repeats/Cas9-engineered ZR75-1 breast cancer cells with different ZNF423 SNP genotypes, striking differences in cellular responses to metformin, either alone or in the combination of tamoxifen, were observed in both cell culture and the mouse xenograft model.

CONCLUSIONS

We found that AMPK signaling is modulated by the ZNF423 rs9940645 SNP in estrogen and SERM-dependent fashion. The ZNF423 rs9940645 SNP affects metformin response in breast cancer and could be a potential biomarker for tailoring the metformin treatment.

Developmental malformations resulting from high-dose maternal tamoxifen exposure in the mouse

Tamoxifen is an estrogen receptor (ER) ligand with widespread use in clinical and basic research settings. Beyond its application in treating ER-positive cancer, tamoxifen has been co-opted into a powerful approach for temporal-specific genetic alteration. The use of tamoxifen-inducible Cre-recombinase mouse models to examine genetic, molecular, and cellular mechanisms of development and disease is now prevalent in biomedical research. Understanding off-target effects of tamoxifen will inform its use in both clinical and basic research applications. Here, we show that prenatal tamoxifen exposure can cause structural birth defects in the mouse. Administration of a single 200 mg/kg tamoxifen dose to pregnant wildtype C57BL/6J mice at gestational day 9.75 caused cleft palate and limb malformations in the fetuses, including posterior digit duplication, reduction, or fusion. These malformations were highly penetrant and consistent across independent chemical manufacturers. As opposed to 200 mg/kg, a single dose of 50 mg/kg tamoxifen at the same developmental stage did not result in overt structural malformations. Demonstrating that prenatal tamoxifen exposure at a specific time point causes dose-dependent developmental abnormalities, these findings argue for more considerate application of tamoxifen in Cre-inducible systems and further investigation of tamoxifen’s mechanisms of action.

Effects of Raloxifene Combined with Low-dose Conjugated Estrogen on the Endometrium in Menopausal Women at High Risk for Breast Cancer

OBJECTIVES

To compare the effects of low-dose conjugated estrogen (CE), raloxifene, and the combination thereof on the endometrium of postmenopausal women.

METHODS

Postmenopausal women between 45 and 60 years of age, with Gail score≥1.67 and no endometrial disorders, were randomly assigned to receive low-dose CE (0.3 mg), raloxifene (60 mg), or combined therapy for 1 year. Transvaginal ultrasound was performed at baseline and every 3 months; the Kupperman Index was assessed at baseline and every 6 months. Endometrial biopsies were performed if endometrial thickness (ET) was ≥5 mm or if vaginal bleeding occurred. The primary outcome was the occurrence of ET≥5 mm over the one-year period.

RESULTS

Seventy-three women were randomly assigned and analyzed on an intent-to-treat basis. Eight, three, and four women in the CE, raloxifene, and combination groups, respectively, exhibited ET≥5 mm. No genital bleeding was reported in the combination group. Endometrial biopsy revealed atrophy or polyps in all groups, with one patient in the CE group exhibiting a proliferative endometrium without atypia. At 6 months, there was a progressive increase in mean ET in the CE group, but not in the other two groups, with statistically significant differences at 6, 9, and 12 months. Mean scores for vasomotor symptoms and Kupperman Index favored the CE and combination groups over raloxifene.

CONCLUSION

Combined raloxifene and low-dose CE decreased the severity of menopausal symptoms to a similar extent as CE alone and had similar effects as raloxifene alone on the endometrium.

27-Hydroxycholesterol, an endogenous selective estrogen receptor modulator

Estrogen receptors (ERs) mediate the actions of the steroidal estrogens, and are important for the regulation of several physiological and pathophysiological processes, including reproduction, bone physiology, cardiovascular physiology and breast cancer. The unique pharmacology of the ERs allows for certain ligands, such as tamoxifen, to elicit tissue- and context-specific responses, ligands now referred to as selective estrogen receptor modulators (SERMs). Recently, the cholesterol metabolite 27-hydroxychoelsterol (27HC) has been defined as an endogenous SERM, with activities in atherosclerosis, osteoporosis, breast and prostate cancers, and neural degenerative diseases. Since 27HC concentrations closely mirror those of cholesterol, it is possible that 27HC mediates many of the biological effects of cholesterol. This paper provides an overview of ER pharmacology and summarizes the work to date implicating 27HC in various diseases. Wherever possible, we highlight clinical data in support of a role for 27HC in the diseases discussed.

New Transgenic Mouse Lines for Selectively Targeting Astrocytes and Studying Calcium Signals in Astrocyte Processes In Situ and In Vivo

Astrocytes exist throughout the nervous system and are proposed to affect neural circuits and behavior. However, studying astrocytes has proven difficult because of the lack of tools permitting astrocyte-selective genetic manipulations. Here, we report the generation of Aldh1l1-Cre/ERT2 transgenic mice to selectively target astrocytes in vivo. We characterized Aldh1l1-Cre/ERT2 mice using imaging, immunohistochemistry, AAV-FLEX-GFP microinjections, and crosses to RiboTag, Ai95, and new Cre-dependent membrane-tethered Lck-GCaMP6f knockin mice that we also generated. Two to three weeks after tamoxifen induction, Aldh1l1-Cre/ERT2 selectively targeted essentially all adult (P80) brain astrocytes with no detectable neuronal contamination, resulting in expression of cytosolic and Lck-GCaMP6f, and permitting subcellular astrocyte calcium imaging during startle responses in vivo. Crosses with RiboTag mice allowed sequencing of actively translated mRNAs and determination of the adult cortical astrocyte transcriptome. Thus, we provide well-characterized, easy-to-use resources with which to selectively study astrocytes in situ and in vivo in multiple experimental scenarios.

Minireview: Lymphangioleiomyomatosis (LAM): The "Other" Steroid-Sensitive Cancer

Lymphangioleiomyomatosis (LAM) is a devastating rare lung disease affecting primarily childbearing age women in which tumors consisting of abnormal smooth-muscle-like cells grow within the lungs and progressively lead to loss of pulmonary function. LAM cells metastasize to the lungs, predominantly through the lymphatics; however, the source of the LAM cell is still unknown. LAM cells contain inactivating mutations in genes encoding tuberous sclerosis 1 or 2, proteins that normally limit cell growth through suppression of mammalian target of rapamycin complex 1. As of today, sirolimus (an mammalian target of rapamycin complex 1 inhibitor) is the only treatment, available for LAM patients that is approved by the Food and Drug Administration; however, this drug and others in its class provide stabilization but not remission of LAM. One of the biggest problems in treating LAM is that both the origin of the LAM cells and the mechanism of the sexual dimorphism in LAM are still not understood. LAM cells express estrogen and progesterone receptors, and lung function declines during periods of high circulating estrogen levels. Moreover, numerous basic research studies find that estrogen is a key driving force in LAM cell proliferation, migration, and metastasis. In this review, we highlight recent insights regarding the role of steroid hormones in LAM and discuss possible explanations for the profound female sexual dimorphism of LAM.

Genistein suppresses the isoproterenol-treated H9c2 cardiomyoblast cell apoptosis associated with P-38, Erk1/2, JNK, and NFκB signaling protein activation

Heart disease (HD) is associated with estrogen and therefore gender and menopausal status. In addition, clinical evidence shows that increased serum norepinephrine is found in patients with HD. Therefore, this study aimed to investigate the cardio-protective effect of genistein, a selective estrogen receptor modulator (SERM) from soy bean extract, in H9c2 cardiomyoblast cells treated with isoproterenol (ISO), a norepinephrine analog. In this in vitro model, image data and results from western blotting shown that ISO treatment was capable of inducing cellular apoptosis, especially the mitochondrial dependent pathway. Treatment of genistein could suppress the expression of mitochondrial pro-apoptotic proteins including Bad, caspase-8, caspase-9, and caspase-3 in H9c2 treated with ISO. By contrast, several survival proteins were expressed in H9c2 treated with genistein, such as phosphor (p)-Akt, p-Bad, and p-Erk1/2. Furthermore, we confirmed that the protective role of genistein was partially mediated through the expression of Erk1/2, Akt, and NF κ B proteins by adding several pathway inhibitors. These in vitro data suggest that genistein may be a safe and natural SERM alternative to hormone therapy in cardio-protection.

[Secondary osteoporosis UPDATE. Drugs under development for metabolic bone disease]

For the treatment of osteoporosis, anti-resorptive agents including bisphosphonates and raloxifene are widely used. As new anti-resorptive drugs, anti-RANKL antibody and cathepsin K inhibitor are under development. Among bone anabolic agents, daily subcutaneous injection of teriparatide will soon become available in Japan. In addition, new anabolic agents such as calcilitycs and anti-sclerostin antibody are under clinical or preclinical development for the treatment of osteoporosis.

[Drugs under development for osteoporosis ]

Osteoporosis is a disease in which the density and quality of bone is reduced, leading to an increase in fragility fractures. Osteoporosis is a major health threat affecting more than 10 million people in Japan. Emerging evidence has shown that anti-resorptive drugs such as bisphosphonates and raloxifene efficiently increase bone mass and prevent osteoporotic fractures by maintaining bone homeostasis. In addition, anabolic drugs such as parathyroid hormone and novel anti-resorptive drugs such as anti-RANKL drugs and cathepsin K inhibitors, which directly target osteoclasts are under development. In this review, we would like to summarize the current status of the development of anti-osteoporotic drugs.

Breast cancer, estrogen receptor and ligands

This review emphasizes the relationship of breast cancer, estrogen receptor and ligands, especially the centrality of the estrogen receptor, which mediates on one hand the hormone-induced gene transcription and on the other hand the anti-estrogen action against breast cancer. The characterization of the estrogen receptor ligand-binding domain co-crystallized with agonists or antagonists provided a molecular basis to gain an insight into the regulation of estrogen receptor and, thereby, to describe the mechanism of the hormone therapy in treating breast cancer.

[Newly developed drugs for osteoporosis in overseas and their future roles for the therapy]

Bisphosphonates are widely used, though gastrointestinal tolerance is a problem on daily administration. Intermittent regimen, from once weekly to once yearly, is now available in overseas and can overcome GI adverse events. New generation of anti-resorptive agents (anti-RANKL antibody and a new SERM, bazedoxifene) are promising and will be soon available for the treatment of osteoporosis. Anabolic agents such as teriparatide and strontium ranelate have marked effects on BMD and reduction on fracture risk. While none of these options is suitable for everyone, the range of future available therapies does mean that most patients can find an intervention that is effective and acceptable.

Early life and adult exposure to isoflavones and breast cancer risk

Soy and red-clover isoflavones are commonly consumed within the diet or as a dietary supplement due to a range of presumed beneficial health benefits. These isoflavones are thought to protect against heart diseases as well as breast and other types of cancer. Isoflavones are structurally similar to estrogens and may act as estrogen agonists or antagonists by binding to estrogen receptors. Because of an increased use of isoflavones in processed foods and dietary supplements as well as the greater consumption of soy products, dietary intakes of isoflavones are increasing in children and adolescents in North America. Estrogens are a known component of numerous hormone related cancers including breast cancer. It is with these facts in mind that we review the existing epidemiological and experimental animal studies for a resolution to a proposed correlation between increased isoflavone consumption and breast cancer. There is conflicting evidence from epidemiological, intervention and experimental animal studies regarding the chemopreventing effects of soy isoflavones in breast cancer. Isoflavones are weak estrogens and their effect depends upon the dose, time of exposure and species involved. It would, therefore, not be safe to indisputably accept soy or red-clover as a source of isoflavone resource to prevent breast cancer.

Medicinal chemistry and emerging strategies applied to the development of selective estrogen receptor modulators (SERMs)

Selective estrogen receptor modulators (SERMs), known previously as "antiestrogens", are a new category of therapeutic agents used for the prevention and treatment of diseases such as osteoporosis and breast cancer. SERMs act as ER-agonist in some tissues while acting as ER-antagonist in others based on conformational change of the receptors, particularly at the helix 12. Currently, there are two classes of clinically approved SERMs; triphenylethylene derivatives (e.g., tamoxifen) and benzothiophene derivatives (e.g., raloxifene). Tamoxifen, raloxifene and toremifene are the most widely used SERMs. Tamoxifen, an antagonist of the breast tissue, is the first clinically identified compound with noticeable SERM activity. Although tamoxifen has been very successful in breast cancer treatment, its agonistic effect on the uterus is said to be associated with increase risk of developing endometrial cancer. Ideally, it is presumed that SERMs should selectively act as an agonist in the bone and brain while simultaneously acting as an antagonist in the breast and uterus. Therefore, the therapeutic goal of SERMs is the prevention of estrogen deficiency diseases without promoting estrogen-associated tumor growth. Therefore, the objective of this review is to summarize various effects that have been applied in improving the tissue-selectivity of SERMs, highlighting the emerging understanding of their mechanism of actions in selected target tissues and the development of the SERMs. The significance in recent discovery of selective estrogen receptor alpha modulators, SERAMs will also be reviewed.

Activation of mitogenic pathways and sensitization to estrogen-induced apoptosis: two independent characteristics of tamoxifen-resistant breast cancer cells?

Paradoxical induction of apoptosis by estrogen has been described previously for estrogen-deprived and antiestrogen-resistant breast cancer cells. In this study we analyzed the possible interrelations between cell sensitization to estrogen apoptotic action and cell ability to (anti)estrogen-independent growth. Using tamoxifen-resistant sublines derived from the parent MCF-7 breast cancer cells by long-term tamoxifen treatment we demonstrated that resistant cells are characterized by increased level of EGF receptor and unexpected increase of VEGF receptor 2 (Flk-1/KDR) and its specific ligand, VEGF-A. The importance of the VEGF signaling in the autocrine regulation of cell growth was indicated by the ability of VEGF inhibitor, soluble fragment of Flt-1/Fc chimera, to suppress the phosphorylation of MAP kinases as well as to inhibit the estrogen-independent growth of MCF-7 cells. Sensitization of tamoxifen-resistant cells to estrogen-induced apoptosis required the additional continuous cultivation in steroid-depleted medium and did not depend on the activity of both EGF and VEGF pathways. Finally, we showed that treatment of the cells with 17beta-estradiol (10(-9) M) resulted in a marked increase in p53 level both in the resistant cells undergoing apoptosis and in the parent MCF-7 cells insensitive to apoptotic estrogen action. These data provide an important support for the existence of a disbalance between pro- and anti-apoptotic machinery in the resistant breast cancer cells that forms independently of the acquired ability to estrogen-independent growth.

[Treatment of osteoporosis from the socioeconomic perspectives]

Health economic evaluation for osteoporosis suffers from methodological limitations. For example, osteoporosis results in various types of fractures each with different impact on patients. Another example is that some therapeutic drugs have extraskeletal benefits and adverse events. Osteoporosis and resultant fracture has profound effects on patients' life expectancy and quality of life, which, however, is not well understood. To promote the health economic evaluation for osteoporosis is our urgent research project in Japan.

Large effects from small exposures. III. Endocrine mechanisms mediating effects of bisphenol A at levels of human exposure

Over 6 billion pounds per year of the estrogenic monomer bisphenol A (BPA) are used to manufacture polycarbonate plastic products, in resins lining metal cans, in dental sealants, and in blends with other types of plastic products. The ester bond linking BPA molecules in polycarbonate and resins undergoes hydrolysis, resulting in the release of free BPA into food, beverages, and the environment, and numerous monitoring studies now show almost ubiquitous human exposure to biologically active levels of this chemical. BPA exerts estrogenic effects through the classical nuclear estrogen receptors, and BPA acts as a selective estrogen receptor modulator. However, BPA also initiates rapid responses via estrogen receptors presumably associated with the plasma membrane. Similar to estradiol, BPA causes changes in some cell functions at concentrations between 1 pM and 1 nM, and the mean and median range of unconjugated BPA measured by multiple techniques in human pregnant maternal, fetal, and adult blood and other tissues exceeds these levels. In contrast to these published findings, BPA manufacturers persist in describing BPA as a weak estrogen and insist there is little concern with human exposure levels. Our concern with human exposure to BPA derives from 1) identification of molecular mechanisms mediating effects in human and animal tissues at very low doses, 2) in vivo effects in experimental animals caused by low doses within the range of human exposure, and 3) widespread human exposure to levels of BPA that cause adverse effects in animals.

Tibolone Improves Myocardial Perfusion in Postmenopausal Women With Ischemic Heart Disease

OBJECTIVES

We sought to determine the effect of tibolone on myocardial perfusion in postmenopausal women with ischemic heart disease.

BACKGROUND

Tibolone is a steroid that relieves climacteric symptoms and prevents osteoporosis. Recent studies have suggested a cardioprotective effect of this compound. However, its role on myocardial perfusion remains uncertain.

METHODS

Single-photon emission computed tomography myocardial perfusion imaging was performed in 26 postmenopausal women. Patients were randomly assigned to tibolone for six months (treatment group) or to usual care (control group). All women underwent cardiac imaging at baseline and at six months.

RESULTS

Mean stress perfusion defect (summed stress score) was moderate and did not differ between the two groups (8 +/- 3 vs. 9 +/- 4; p = NS). Summed difference score also was similar for both groups (7 +/- 3 vs. 8 +/- 3; p = NS). The six-month study revealed that summed stress and summed difference scores significantly improved in the treatment group (to 3 +/- 3 and to 2 +/- 2; p < 0.001) whereas it remained unchanged for control patients (to 10 +/- 4 and to 8 +/- 2; p = NS).

CONCLUSIONS

In postmenopausal women with ischemic heart disease, six months of therapy with tibolone significantly improved stress myocardial perfusion and the "amount of ischemia."

Changes in RANKL/OPG/RANK gene expression in peripheral mononuclear cells following treatment with estrogen or raloxifene

The RANKL/OPG/RANK pathway is the key mediator of osteoclastogenesis. Mononuclear cells may be implicated in post-menopausal osteoporosis. The effect of estrogen or raloxifene on bone resorption and the expression of RANKL/OPG/RANK in peripheral blood mononuclear cells (PBMCs) was examined. Twenty-nine women with post-menopausal osteoporosis were treated with estrogen (HRT) or raloxifene for 12 months. Bone mineral density (BMD) was measured at baseline and at 12 months at the spine and hip. Serum C-terminal telopeptide (CTX) and OPG were measured at baseline and at 1, 3, 6 and 12 months. PBMCs were isolated from 17 women and changes in RANKL, OPG and RANK mRNA were determined. The effects of estrogen or raloxifene in PBMCs in vitro were also assessed. BMD increased following treatment (lumbar spine % change mean [S.E.M.]: 4.3% [0.9], p<0.001). Serum CTX decreased (6 months: -43.7% [6.0], p<0.0001). Serum OPG declined gradually (12 months: -26.4% [4.4], p<0.001). RANKL, OPG and RANK gene expression decreased (6 months: RANKL 50.0% [24.8] p<0.001, OPG: 21.7% [28] p<0.001, RANK: 76.6% [10.2] p=0.015). Changes in OPG mRNA correlated with changes in BMD (r=-0.53, p=0.027) and CTX (r=0.7, p=0.0044). Down-regulation in RANKL, OPG, RANK mRNA and reduction in bone resorption was also seen in vitro. These results suggest that the expression of RANKL/OPG/RANK in PBMCs are responsive to the slowing in bone turnover/remodeling associated with treatment with estrogen or raloxifene. Further confirmatory studies are needed.

Melatonin-estrogen interactions in breast cancer

In this article, we review the experimental data supporting an oncostatic role of melatonin on hormone-dependent mammary tumors. Beginning with the evidence on the role of estrogens in breast cancer etiology and mammary tumor growth, we summarize the actual therapeutic strategies with estrogens as a target. Additionally, we demonstrate that melatonin fulfills all the requirements to be considered as an antiestrogenic drug which shares properties with drugs of the two main pharmacological groups of substances which interact with the estrogen-signaling pathways such as: (i) drugs that act through the estrogen receptor interfering with the effects of endogenous estrogens; and (ii) drugs that interfere with the synthesis of estrogens by inhibiting the enzymes controlling the interconversion from their androgenic precursors. Furthermore, melatonin decreases circulating levels of estradiol. These three antiestrogenic mechanisms suggest that melatonin may have an important role in the prevention and treatment of hormone-dependent mammary cancer.

Transcriptional regulation by phytoestrogens in neuronal cell lines

Widespread epidemiological data support the notion that high isoflavone intake is safe and may provide health benefits similar to estrogen. Evidence from rodents shows that certain phytoestrogens can act as estrogen receptor (ER) ligands in the brain. This study sought to determine the estrogenic profile of food-borne phytoestrogens in neuronal cell lines using physiologically attainable concentrations. At sub-micromolar concentrations genistein, daidzein, and zearalenone stimulated ERalpha and ERbeta-dependent transcription in Neuro2A cells co-transfected with ERs and simple and complex estrogen-response-element (ERE) containing promoters, although compounds were more active in the presence of ERbeta. In SN56, neuronblastoma cells expressing endogenous ERs, only genistein mimicked estrogen regulation of progesterone receptor steady state mRNA levels. Unlike pharmaceutical SERMs, phytoestrogens did not stimulate an AP-1-dependent promoter. Micromolar concentrations of phytoestrogens did not antagonize physiological estrogen concentrations or antagonist activation of an AP-1-dependent promoter. These results demonstrate that food-borne phytoestrogens, particularly those found in soy, act as ERE-, but not AP-1-dependent transcriptional activators in neurons in the absence of estrogen, and dietary levels of these compounds do not act as antagonists to physiological estrogen concentrations.

Postmenopausal hormone therapy before and after breast cancer: clinical experiences

Conventional oestrogen-based hormone therapy (HT) increases the incidence of breast pain and tenderness, mammographic density and the risk of breast cancer. Combined oestrogen plus progestogen therapy (EPT) increases the risk of breast cancer to a greater degree than oestrogen alone (ET). Attention must therefore be focused on identifying women at risk of breast cancer or on producing a HT that has fewer breast side effects. Randomised controlled trials have shown that while EPT induces breast tenderness or pain in up to 50% of women and increases mammographic density in up to 70% during the first year of treatment, only about as many as one-tenth women report breast tenderness or pain with tibolone and increases in mammographic density are rare, occurring with a similar incidence as seen in untreated controls. Many women with breast cancer suffer vasomotor symptoms rather than risk recurrence with conventional HT. However, in a small randomised controlled trial in women with early breast cancer undergoing adjuvant tamoxifen treatment, tibolone reduced hot flushes, night sweats and improved quality of life compared with placebo.

Estrogenic activity of an antioxidant, nordihydroguaiaretic acid (NDGA)

Nordihydroguaiaretic acid (NDGA), an antioxidant which has been used to preserve oils and foods, has recently become well known as a putative anticancer agent. Although NDGA is a member of the lignan family, its hormonal activities have not been well investigated. Here we show that NDGA has in vitro estrogenic activity in the ERE-luc reporter system using NIH3T3 cells, and in the estrogen-responsive cell growth assay in a pituitary cell line, MtT/E-2. Uterotropic assay in rats indicated that NDGA has estrogenic activity in vivo as well, albeit weak. Interestingly it preferentially induced ERalpha mediated ERE-luc activity, although it showed similar binding affinity to both ERalpha and ERbeta. With ERbeta, on the other hand, NDGA showed only weak agonistic action, and antagonized the estrogenic action of 17beta-estradiol when the two were coadministered. These data suggest that NDGA is an estrogenic agonist for ERalpha : ERE transcription and a mixed agonist/antagonist for ERbeta mediated ERE transactivation.

Hormone replacement therapy in women with a history of breast cancer

Health care professionals in modern Western societies will meet an increasing number of women surviving breast cancer. How the menopause of these women should be treated is still an open question. Use of hormone replacement therapy (HRT) may, at least in theory, increase the risk for recurrence of cancer, but its categoric refusal is a double-edged sword because it also denies these women all the undisputable health benefits HRT provides. This refusal is not, however, supported by the observational data available so far on this question, because HRT has not increased the risk for breast cancer recurrence. In fact, it is well established that HRT abolishes hot flushes and improves significantly these patients' quality of life. At present, we have no effective nonhormonal alternatives for the control of vasomotor symptoms, and the efficacy of phytoestrogens in the treatment of menopausal symptoms is unproven. Selective estrogen receptor modulators (SERMs) which protect against osteoporosis and perhaps also against breast cancer, and which may have beneficial effects on the cardiovascular system, aggravate hot flushes and are therefore not useful, at least in the first postmenopausal years. In some countries, progestins are often prescribed for the control of such patients' vasomotor symptoms, but their safety has never been assessed in clinical trials, and in theory they can be harmful. Randomized clinical trials (RCT) on the use of HRT in breast cancer survivors are underway, but their completion will take years, and even these may be open to criticism. Tibolone may appear to be an appealing alternative for HRT, but it should also be studied with RCTs in this indication. At present, a patient with a history of breast cancer must be given balanced information as to the possible benefits and risks of HRT, and she herself must make the decision whether or not to start HRT.

Current strategies for anticancer chemoprevention and chemoprotection

Relatively new targets in drug design projects in cancer pharmacology include cytostatic agents, immune system modulators, and angiogenesis inhibitors. Preventive oncology applies pharmacological agents to reverse, retard, or halt progression of neoplastic cells to invasive malignancy. Prevention of cancer, however, can be accomplished through many strategies, including changes in diet and lifestyle. For example, the vast majority of lung cancers (80-90%) can be attributed to cigarette smoking and therefore, the most effective primary preventive strategy for lung cancer is to quit smoking. Chemoprevention through interruption of multistage careinogenesis include different molecular targets. Selective estrogen receptor modulators (SERMs) act as estrogen receptor (ER) agonists. Ligands for the peroxisome proliferator-activated receptor gamma (PPAR-gamma) suppress breast carcinogenesis in experimental models and induce differentiation of human liposarcoma cells. Selective PPAR modulators (SPARMs), by analogy to the SERM concept, are designed to have desired effects on specific genes relevant to carcinogenesis. Enzymatic approach in endocrine-related tumors involve inhibition of aromatase to prevent breast cancer and inhibition of 5-alpha-reductase to prevent prostate cancer. Down-regulation of inflammatory prostaglandin synthesis by inhibition of cyclooxygenase-2 (COX-2). inhibition of the inducible nitric oxide synthase (iNOS), and stimulation of phase II detoxication system, are currently examined in experimental models and clinical trials. Overall, potential targets in preventive strategies to reduce the risk of cancer involve agonists of endocrine receptors, factors down-regulating inflammation, factors inducing programmed cell death (PCD)/apoptosis, enzymatic inhibitors and gene therapy.

North American Menopause Society. Management of postmenopausal osteoporosis: position statement of the North American Menopause Society

OBJECTIVE

The North American Menopause Society (NAMS) established a goal to create an evidence-based position statement regarding the management of postmenopausal osteoporosis.

DESIGN

NAMS followed the general principles established for evidence-based guidelines to create this document. A MEDLINE search was conducted. Clinicians and researchers acknowledged to be experts in the field of osteoporosis were enlisted to review the evidence. The NAMS Board of Trustees reviewed and approved the final document.

RESULTS

Osteoporosis, which has its highest rate of occurrence in postmenopausal women, increases the risk for fractures, including hip and spine fractures. These injuries are often associated with particularly high morbidity and mortality. Given the health implications of osteoporotic fractures, the primary goal of osteoporosis therapy is to prevent fractures by slowing or preventing bone loss, maintaining bone strength, and minimizing or eliminating factors that may contribute to falls. The evaluation of postmenopausal women for osteoporosis risk requires the recording of a medical history, a physical examination, and diagnostic tests. Major risk factors for osteoporosis are age, genetics, lifestyle (especially nutrition), and menopausal status. Management focuses first on nonpharmacologic measures, such as a balanced diet including adequate calcium and vitamin D intakes, appropriate exercise, smoking cessation, avoidance of excessive alcohol intake, and fall prevention. If pharmacologic therapy is indicated, FDA-approved options are estrogens (prevention only), bisphosphonates and selective estrogen-receptor modulators (prevention and treatment), and calcitonin (treatment only).

CONCLUSIONS

Management of postmenopausal osteoporosis involves identifying the potential risk for osteoporosis and osteoporotic fracture, followed by measures that focus on reducing modifiable risk factors through lifestyle changes and, if indicated, pharmacologic therapy.