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- SERMs attenuate estrogen-induced malignant transformation of human breast epithelial cells by upregulating detoxification of oxidative metabolites. [JOURNAL ARTICLE]
- Cancer Prev Res (Phila) 2014 Mar 5.
The risk of developing hormone-dependent cancers with long-term exposure to estrogens is attributed both to proliferative, hormonal actions at the estrogen receptor (ER), and chemical carcinogenesis elicited by genotoxic, oxidative estrogen metabolites. Non-tumorigenic MCF-10A human breast epithelial cells are classified as ER(-) and undergo estrogen-induced malignant transformation. Selective estrogen receptor modulators (SERMs), in use for breast cancer chemoprevention and for post-menopausal osteoporosis, were observed to inhibit malignant transformation, as measured by anchorage-independent colony growth. This chemopreventive activity was observed to correlate with reduced levels of oxidative estrogen metabolites, cellular ROS, and DNA oxidation. The ability of raloxifene, desmethylarzoxifene (DMA), and bazedoxifene to inhibit this chemical carcinogenesis pathway was not shared by 4-hydroxytamoxifen. Regulation of Phase 2 rather than Phase 1 metabolic enzymes was implicated mechanistically: raloxifene and DMA were observed to upregulate sulfotransferase (SULT 1E1) and glucuronidase (UGT 1A1). The results support upregulation of Phase 2 metabolism in detoxification of catechol estrogen metabolites leading to attenuated ROS formation as a mechanism for inhibition of malignant transformation by a subset of clinically important SERMs.
- Genotoxicity of the some selective estrogen receptor modulators: a review. [JOURNAL ARTICLE]
- Cytotechnology 2014 Mar 5.
The objective of this article is to review genotoxicological profile of the major selective estrogen receptor modulators, including clomiphene, tamoxifen, toremifene, raloxifene. These drugs have been used for infertility treatment and breast cancer prevention in high risk-women. However, some studies reported that especially tamoxifen is a genotoxic agent and is related with endometrial cancer. Our review indicate that clomiphene and tamoxifen were found as genotoxic agent in majority of the tests. However published reports showed that toremifene is a weakly genotoxic agent. The genotoxic effects of raloxifene are still poorly known. Further genotoxicity studies should be conducted especially for raloxifene.
- Diary of hot flashes reported upon occurrence: results of a randomized double-blind study of raloxifene, placebo, and paroxetine. [JOURNAL ARTICLE]
- Menopause 2014 Feb 24.
This trial examined diaries of hot flash events reported upon occurrence to assess the test/retest reliability of the diaries and their ability to measure treatment effects on hot flash frequency and severity.Forty-two postmenopausal women (aged ≥40 y; 5-50 hot flashes/wk) were randomized (3:3:1) to placebo, raloxifene 60 mg, or paroxetine 20 mg daily for 12 weeks. Diaries of hot flash frequency and severity were evaluated at 1-week intervals (twice before study treatment and thrice during study treatment).Forty-one women were evaluated. Baseline characteristics were similar between groups (eg, mean, 29.8 hot flashes/wk). Concordance correlation coefficients between screening (week -2) and baseline (week -1) measures of hot flash frequency and severity were 0.73 and 0.71, respectively. After 12 weeks, the mean (95% CI) percent changes from baseline in weekly hot flash frequency were as follows: placebo, -37.4% (-60.9 to -14.0); raloxifene, -14.2% (-37.7 to 9.3); paroxetine, -49.8% (-88.6 to -11.0); the mean (95% CI) percent changes in hot flash severity were as follows: placebo, -39.9% (-69.1 to -10.8); raloxifene, -9.6% (-38.8 to 19.6); paroxetine, -36.6% (-84.7 to 11.5). There were no significant differences in hot flash diary results between treatment groups.Measures of hot flash frequency and severity show acceptable test/retest reliability between screening and baseline. Reductions in vasomotor symptoms by raloxifene are numerically less than those seen with placebo, but no statistically significant treatment differences have been documented in this small study. The large effect of placebo and the significant reduction in vasomotor symptoms by paroxetine are consistent with other studies. The diary seems to be suitable for use in hot flash clinical trials.
- Systematic review of the use of bone turnover markers for monitoring the response to osteoporosis treatment: the secondary prevention of fractures, and primary prevention of fractures in high-risk groups. [Journal Article]
- Health Technol Assess 2014 Feb; 18(11):1-180.
There is currently no standard practice for the monitoring of patients receiving treatment for osteoporosis. Repeated dual-energy X-ray absorptiometry (DXA) is commonly used for monitoring treatment response, but it has its limitations. Bone turnover markers have advantages over DXA as they are non-invasive, relatively cheap and can detect changes in bone turnover rates earlier. However, they do have disadvantages, particularly high within- and between-patient variability. The ability of bone turnover markers to identify treatment non-responders and predict future fracture risk has yet to be established.We aimed to determine the clinical effectiveness, test accuracy, reliability, reproducibility and cost-effectiveness of bone turnover markers for monitoring the response to osteoporosis treatment.We searched 12 electronic databases (including MEDLINE, EMBASE, The Cochrane Library and trials registries) without language restrictions from inception to March 2012. We hand-searched three relevant journals for the 12 months prior to May 2012, and websites of five test manufacturers and the US Food and Drug Administration (FDA). Reference lists of included studies and relevant reviews were also searched.A systematic review of test accuracy, clinical utility, reliability and reproducibility, and cost-effectiveness of two formation and two resorption bone turnover markers, in patients being treated for osteoporosis with any of bisphosphonate [alendronate (Fosamax(®), MSD), risedronate (Actonel(®), Warner Chilcott Company), zolendronate (Zometa(®), Novartis)], raloxifene (Evista(®), Eli Lilly and Company Ltd), strontium ranelate (Protelos(®), Servier Laboratories Ltd), denosumab (Prolia(®), Amgen Ltd) or teriparatide (Forsteo(®), Eli Lilly and Company Ltd), was undertaken according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Given the breadth of the review question, a range of study designs and outcome measures were eligible. The development of a decision model was planned to determine the cost-effectiveness of bone turnover markers for informing changes in patient management if clinical effectiveness could be established.Forty-two studies (70 publications) met the inclusion criteria; none evaluated cost-effectiveness. Only five were randomised controlled trials (RCTs); these assessed only the impact of bone marker monitoring on aspects of adherence. No RCTs evaluated the effectiveness of bone turnover marker monitoring on treatment management. One trial suggested that feedback of a good response decreased non-persistence [hazard ratio (HR) 0.71, 95% confidence interval (CI) 0.53 to 0.95], and feedback of a poor response increased non-persistence (HR 2.22, 95% CI 1.27 to 3.89); it is not clear whether or not the trial recruited a population representative of that seen in clinical practice. Thirty-three studies reported results of some assessment of test accuracy, mostly correlations between changes in bone turnover and bone mineral density. Only four studies reported on intra- or interpatient reliability and reproducibility in treated patients. Overall, the results were inconsistent and inconclusive, owing to considerable clinical heterogeneity across the studies and the generally small sample sizes. As clinical effectiveness of bone turnover monitoring could not be established, a decision-analytic model was not developed.There was insufficient evidence to inform the choice of which bone turnover marker to use in routine clinical practice to monitor osteoporosis treatment response. The research priority is to identify the most promising treatment-test combinations for evaluation in subsequent, methodologically sound, RCTs. In order to determine whether or not bone turnover marker monitoring improves treatment management decisions, and ultimately impacts on patient outcomes in terms of reduced incidence of fracture, RCTs are required. Given the large number of potential patient population-treatment-test combinations, the most promising combinations would initially need to be identified in order to ensure that any RCTs focus on evaluating those strategies. As a result, the research priority is to identify these promising combinations, by either conducting small variability studies or initiating a patient registry to collect standardised data.The National Institute for Health Research Health Technology Assessment programme.
- Effects of Ospemifene on Breast Tissue Morphology and Proliferation: A Comparative Study Versus Other Selective Estrogen Receptor Modulators in Ovariectomized Rats. [JOURNAL ARTICLE]
- Horm Metab Res 2014 Feb 13.
Ospemifene is a tissue-selective estrogen agonist/antagonist that was recently approved for the treatment of dyspareunia associated with vulvar and vaginal atrophy, which occurs in up to approximately 50% of postmenopausal women. The current analyses were conducted to determine whether ospemifene exhibits estrogenic activity in the mammary glands of ovariectomized rats and to compare potential estrogenic activity with selective estrogen receptor modulators (tamoxifen, raloxifene, and toremifene). Three separate studies with differing durations (6, 9, and 28 days) were conducted using similar procedures in ovariectomized Sprague-Dawley rats. Estradiol treatment and sham-treated ovariectomized rats were used as positive and negative controls, respectively. Cell proliferation was examined using labeled 5-bromo-2-deoxyuridine; cytoplasmic prolactin was characterized with antibody staining. The morphology of the mammary gland was studied by histological staining of sections from the right fourth mammary glands, and the excised gland from the left side was used for counting the lobulus number. Neither ospemifene nor selective estrogen receptor modulators substantially induced 5-bromo-2-deoxyuridine staining, altered the morphology of the mammary glands, or changed prolactin immunostaining in ovariectomized rats compared with the ovariectomized controls. With the exception of toremifene, the selective estrogen receptor modulators did not cause a substantial induction in mammary gland lobuli. Estradiol had effects opposite to those of the selective estrogen receptor modulators in these studies. Ospemifene exhibited no substantial estrogenic activity in the mammary gland of ovariectomized rats. Activity in the mammary gland of ovariectomized rats with ospemifene was comparable to raloxifene and tamoxifen.
- Differential effects of menopausal therapies on the endometrium. [JOURNAL ARTICLE]
- Menopause 2014 Feb 10.
Currently available treatments for menopausal symptoms are associated with differing endometrial safety and endometrium-related tolerability profiles. This article reviews the differential endometrial effects associated with estrogen therapy, estrogen-progestin therapy (EPT), selective estrogen receptor modulators (SERMs), and tissue-selective estrogen complex (TSEC).Searches of electronic databases and of recent presentations at congresses were performed. Articles and abstracts relevant to the endometrial effects of estrogen therapy, EPT, SERMs, and TSECs were summarized in this interpretive literature review.Owing to their effects on the endometrium, cyclic and continuous-combined EPT can induce irregular uterine bleeding. Cyclic EPT may induce endometrial proliferation. Continuous-combined EPT reduces the incidence of endometrial cancer. In the endometrium, SERM activity ranges from essentially neutral to agonist, depending on the individual SERM. Raloxifene, tamoxifen, lasofoxifene, ospemifene, and bazedoxifene (BZA) demonstrated different degrees of endometrial tissue effects in preclinical and clinical studies. BZA inhibits the effects of conjugated estrogens on the endometrium. These effects are attributable to tissue-specific estrogen receptor degradation, which effectively diminishes the molecular target of estrogen activity in the endometrium. Conjugated estrogens/BZA, a TSEC, has a favorable endometrial profile, with incidences of hyperplasia and bleeding/spotting similar to those of placebo.Endometrial safety is a significant hurdle in the development of new hormone therapies for postmenopausal women. Preclinical and clinical findings suggest that BZA has an endometrial profile distinct from those of other SERMs. TSECs are a novel approach to providing relief of menopausal symptoms with adequate endometrial safety profile.
- Comparison of the Inhibitory Effect of Gonadotropin Releasing Hormone (GnRH) Agonist, Selective Estrogen Receptor Modulator (SERM), Antiprogesterone on Myoma Cell Proliferation In Vitro. [Journal Article]
- Int J Med Sci 2014; 11(3):276-81.
Uterine myomas are the most common gynecologic tumor in women of reproductive age. Treatment options of uterine myomas consist of surgical, medical and interventional therapy such as uterine artery embolization or myolysis. Given that it is the most common type of tumor in women of reproductive age, the treatment of uterine myomas must prioritize uterine conservation. There are several drugs for medical treatment of uterine myoma such as gonadotropin releasing hormone (GnRH) agonist, selective estrogen receptor modulator (SERM) and antiprogesterone. The objective of this study was to compare the effect of GnRH agonist, SERM, and antiprogesterone in the treatment of uterine myomas in vitro. The effect of drugs was evaluated through the cell viability assay in cultured leiomyoma cells, western blot analysis of proliferating cell nuclear antigen (PCNA), and BCL-2 protein expression. As a result, mifepristone single-treated group represents the most significant reduction in myoma cell viability and proliferation. When pretreated with leuprolide acetate, raloxifene shows more significant reduction in myoma cell viability and proliferation than mifepristone. This study suggests one of the possible mechanisms how medications act on uterine myoma, especially at the molecular level.
- Incidence and risk of osteonecrosis of the jaw among the Taiwan osteoporosis population. [JOURNAL ARTICLE]
- Osteoporos Int 2014 Feb 11.
Evidence of the incidence and risk of osteonecrosis of the jaw (ONJ) in Asian osteoporosis populations receiving different osteoporosis medications is lacking. We found that there is no excess incidence of or risk for ONJ in osteoporosis patients >50 years old using alendronate as compared with patients using raloxifene or calcitonin under real-world conditions in Taiwan.To provide information on ONJ in Asian populations, this study compares the incidence and risk of ONJ between patients receiving alendronate and those receiving non-bisphosphonate osteoporosis medications in Taiwan.Enrollees in the National Health Insurance Research Database (NHIRD) from 2003 to 2007, aged above 50 years, with vertebral/hip fracture, and new to osteoporosis therapy were recruited. Patients with Paget's disease or cancer during the baseline period were excluded. Patients were classified into either the alendronate or the calcitonin/raloxifene (control) group according to their exposure during follow-up. Previously proposed possible ONJ diagnosis codes were adopted as potential ONJ cases, but qualifying cases also had a repeated ONJ diagnosis within 8 weeks of the first diagnosis and received one or more broad-spectrum oral antibiotics. Cox modeling compared the risk of ONJ between the alendronate and the control groups, which were matched using propensity scores. Results were examined in series sensitivity analyses, including different cumulative dose groups.We found 25 potential ONJ cases in the alendronate (N = 18,030) and 21 in the control groups (N = 25,615). Over the 6-year follow-up period, no increased risk of ONJ in the alendronate group in the original (hazard ratio (HR), 0.87; 95 % confidence interval (CI), 0.47-1.58) or propensity score-matched cohorts (HR, 0.86; 95 % CI, 0.44-1.69) was found. All comparison groups exhibited a similar incidence of ONJ, ranging from 6.9 to 8.2/10,000 person-years.Under real-world conditions, there is no excess risk for ONJ in osteoporosis patients >50 years old using alendronate as compared with patients using raloxifene or calcitonin.
- Alendronate versus Raloxifene for Postmenopausal Women: A Meta-Analysis of Seven Head-to-Head Randomized Controlled Trials. [REVIEW]
- Int J Endocrinol 2014.:796510.
Purpose. The aim of this study was to directly compare the efficacy and the safety of the two agents for postmenopausal women. Methods/Principal Findings. Electronic databases were searched for relevant articles that met our predefined inclusion criteria. Seven randomized controlled trials (RCTs) involving 4054 women were identified and included. Although Aln was more effective than Rlx in increasing bone mineral density (BMD), no statistical differences were observed in reducing the risk of neither vertebral fractures (P = 0.45) nor nonvertebral fractures (P = 0.87) up to two-year followup. Aln reduced the risk of vasomotor (P = 0.006) but increased the risk of diarrhea compared to Rlx (P = 0.01). Our subgroup analysis further indicated the difference between Aln and Rlx in fracture risk and was not materially altered by the administration pattern, the age. The weekly strategy of Aln would further reduce the upper gastrointestinal (GI) disorders and might gain more bone mass increment at lumbar spine compared to its daily treatment. Conclusion. There was no evidence of difference of fracture risk reduction between Aln and Rlx. In addition, age did not obviously influence their relative antifracture efficacy. For Aln the weekly strategy would further reduce the upper GI disorders and gain more bone mass increment compared to the daily treatment. During clinical decision making, the patients' adherence and the related side-effects associated with both drugs should also be taken into account.
- Visualization of network target crosstalk optimizes drug synergism in myocardial ischemia. [Journal Article]
- PLoS One 2014; 9(2):e88137.
Numerous drugs and compounds have been validated as protecting against myocardial ischemia (MI), a leading cause of heart failure; however, synergistic possibilities among them have not been systematically explored. Thus, there appears to be significant room for optimization in the field of drug combination therapy for MI. Here, we propose an easy approach for the identification and optimization of MI-related synergistic drug combinations via visualization of the crosstalk between networks of drug targets corresponding to different drugs (each drug has a unique network of targets). As an example, in the present study, 28 target crosstalk networks (TCNs) of random pairwise combinations of 8 MI-related drugs (curcumin, capsaicin, celecoxib, raloxifene, silibinin, sulforaphane, tacrolimus, and tamoxifen) were established to illustrate the proposed method. The TCNs revealed a high likelihood of synergy between curcumin and the other drugs, which was confirmed by in vitro experiments. Further drug combination optimization showed a synergistic protective effect of curcumin, celecoxib, and sililinin in combination against H2O2-induced ischemic injury of cardiomyocytes at a relatively low concentration of 500 nM. This result is in agreement with the earlier finding of a denser and modular functional crosstalk between their networks of targets in the regulation of cell apoptosis. Our study offers a simple approach to rapidly search for and optimize potent synergistic drug combinations, which can be used for identifying better MI therapeutic strategies. Some new light was also shed on the characteristic features of drug synergy, suggesting that it is possible to apply this method to other complex human diseases.