Selective estrogen receptor modulation and reduction in risk of breast cancer, osteoporosis, and coronary heart disease

New potential selective estrogen receptor modulators in traditional Chinese medicine for treating menopausal syndrome

Women go through several predictable conditions and symptoms during menopause that are caused by age, changes in sex hormone levels, and other factors. Conventional menopause hormone therapy has raised serious concerns about the increased risks of cancers, blood clots, depression, etc. Selective estrogen receptor modulators (SERMs) that can be both agonists and antagonists of estrogen receptors in a tissue-specific manner are being developed to reduce the health concerns associated with menopause hormone therapy. Here, we have searched the Chinese national traditional Chinese medicine (TCM) patent database to identify potential SERM-like compounds with reduced health risks. TCM has been widely used for treating complex symptoms associated with menopause syndrome and thus can be a particularly rich source for pharmaceutical alternatives with SERM properties. After extensive literature review and molecular simulation, we conclude that protopanaxatriol, paeoniflorin, astragalin, catalpol, and hyperoside among others may be particularly promising as SERM-like compounds in treating the menopausal syndrome. Compounds in TCM hold promise in yielding comparable outcomes to hormone therapy but with reduced associated risks, thus presenting promising avenues for their clinical applications.

Effect of hormonal therapy on the otoconial changes caused by estrogen deficiency

Benign paroxysmal positional vertigo (BPPV) is associated with menopause and/or osteopenia. Morphological changes in the otoconial layer have been reported after ovariectomy (OVX). Moreover, hormone replacement therapy decreases BPPV risk. However, knowledge concerning the effect of hormonal therapy on the otoconial changes caused by estrogen deficiency is limited. We aimed to examine the effect of hormonal therapy on otoconial changes caused by estrogen deficiency. We hypothesized that hormonal therapy could reduce otoconial changes caused by OVX. Eight-week-old C57BL/6 mice were divided into four groups: sham operation with implantation of vehicle (sham + v), OVX with implantation of vehicle (OVX + v), OVX with implantation of estradiol (E2) (OVX + E2), and OVX with implantation of raloxifene (RAL) (OVX + RAL) groups. Otoconial layer volume was measured by micro-CT at 4 weeks after OVX or the sham operation. The otic bullae were removed; immunohistochemistry was performed for estrogen receptor alpha and 4-hydroxynonenal. Otoconial layer volume was significantly higher in the OVX + v than in the sham + v group. E2 and RAL significantly reduced these changes in the endometrial layer. The staining of estrogen receptor alpha and 4-hydroxynonenal were stronger in the OVX + v than in the sham + v group but equal in the sham + v, OVX + E2, and OVX + RAL groups. These results indicate that E2 and RAL are effective against morphological changes of the otoconial layer caused by estrogen deficiency via oxidative stress reduction.

Aromatase inhibition increases blood pressure and markers of renal injury in female rats

Aromatase is a monooxygenase that catalyzes the rate-limiting step of estrogen biosynthesis from androgens. Aromatase inhibitors are widely used for the treatment of patients with hormone receptor-positive breast cancer. However, the effects of aromatase inhibitors on cardiovascular and renal health in females are understudied. Given that estrogen is protective against cardiovascular and kidney diseases, we hypothesized that aromatase inhibition elevates blood pressure and induces kidney injury in female Sprague-Dawley rats. Twelve-week-old female rats were implanted with radiotelemetry transmitters to continuously monitor blood pressure. After baseline blood pressure recording, rats were randomly assigned to treatment with the aromatase inhibitor anastrozole (ASZ) or vehicle (Veh) in drinking water. Twenty days after treatment initiation, rats were shifted from a normal-salt (NS) diet to a high-salt (HS) diet for an additional 40 days. Rats were euthanized 60 days after treatment initiation. Body weight increased in both groups over the study period, but the increase was greater in the ASZ-treated group than in the Veh-treated group. Mean arterial pressure increased in ASZ-treated rats during the NS and HS diet phases but remained unchanged in Veh-treated rats. In addition, urinary excretion of albumin and kidney injury marker-1 and plasma urea were increased in response to aromatase inhibition. Furthermore, histological assessment revealed that ASZ treatment increased morphological evidence of renal tubular injury and proximal tubular brush border loss. In conclusion, chronic aromatase inhibition in vivo with ASZ increases blood pressure and markers of renal proximal tubular injury in female Sprague-Dawley rats, suggesting an important role for aromatization in the maintenance cardiovascular and renal health in females.NEW & NOTEWORTHY Aromatase enzyme catalyzes the rate-limiting step in estrogen biosynthesis. Aromatase inhibitors are clinically used for the treatment of patients with breast cancer; however, the impact of inhibiting aromatization on blood pressure and renal function is incompletely understood. The present findings demonstrate that systemic anastrozole treatment increases blood pressure and renal tubular injury markers in female rats fed a high-salt diet, suggesting an important role for aromatization in preserving cardiovascular and renal health in females.

Anti-Osteoporosis Effects of the Fruit of Sea Buckthorn (Hippophae rhamnoides) through Promotion of Osteogenic Differentiation in Ovariectomized Mice

The fruit of Hippophae rhamnoides has been widely used for medicinal purposes because of its anti-inflammatory, antioxidant, antiplatelet, and antimicrobial effects. Since there are no clear reports on the therapeutic efficacy of H. rhamnoides in osteoporosis, this study aimed to confirm the potential use of H. rhamnoides for the treatment of osteoporosis through its osteogenic differentiation-promoting effect in ovariectomized mice. Through an in vitro study, we compared the effects of the EtOH extract of H. rhamnoides fruits (EHRF) on the differentiation of C3H10T1/2, a mouse mesenchymal stem cell line, into osteoblasts based on alkaline phosphatase (ALP) staining and the relative expression of osteogenesis-related mRNAs. The EHRF significantly stimulated the differentiation of mesenchymal stem cells into osteoblasts and showed 7.5 times (* p < 0.05) higher osteogenesis than in the untreated control. A solvent fractionation process of EHRF showed that the hexane-soluble fraction (HRH) showed 10.4 times (** p < 0.01) higher osteogenesis than in the untreated control. Among the subfractions derived from the active HRH by preparative HPLC fractionation, HRHF4 showed 7.5 times (* p < 0.05) higher osteogenesis than in the untreated naïve cells, and HRH and HRHF4 fractions showed 22.6 times (*** p < 0.001) stronger osteogenesis activity than in the negative control. Osteoporosis was induced by excision of both ovaries in 9-week-old female ICR mice for in vivo analysis, and two active fractions, HRH and HRHF4, were administered orally for three months. During the oral administration period, body weight was measured weekly, and bone mineral density (BMD) and body fat density were measured simultaneously using a DEXA machine once a month. In particular, during the in vivo study, the average BMD of the ovariectomized group decreased by 0.0009 g/cm2, whereas the average BMD of the HRH intake group increased by 0.0033 g/cm2 (* p < 0.05) and that of the HRHF4 intake group increased by 0.0059 g/cm2 (** p < 0.01). The HRH and HRHF4 intake groups significantly recovered the mRNA and protein expression of osteogenic genes, including ALP, Osteopontin, Runx2, and Osterix, in the osteoporosis mouse tibia. These findings suggest that the active fractions of H. rhamnoides fruit significantly promoted osteoblast differentiation in mesenchymal stem cells and increased osteogenic gene expression, resulting in an improvement in bone mineral density in the osteoporosis mouse model. Taken together, H. rhamnoides fruits are promising candidates for the prevention and treatment of osteoporosis.

Insights Into the Role of Epigenetic Factors Determining the Estrogen Response in Estrogen-Positive Ovarian Cancer and Prospects of Combining Epi-Drugs With Endocrine Therapy

Ovarian cancer is one of the most lethal malignancies. The population at the risk is continually on the rise due to the acquired drug resistance, high relapse rate, incomplete knowledge of the etiology, cross-talk with other gynecological malignancies, and diagnosis at an advanced stage. Most ovarian tumors are thought to arise in surface epithelium somehow in response to changes in the hormonal environment. Prolonged treatment with hormone replacement therapy (HRT) is also considered a contributing factor. Estrogens influence the etiology and progression of the endocrine/hormone-responsive cancers in a patient-specific manner. The concept of hormonal manipulations got attention during the last half of the 20th century when tamoxifen was approved by the FDA as the first selective estrogen receptor modulator (SERM). Endocrine therapy that has been found to be effective against breast cancer can be an option for ovarian cancer. It is now established that global changes in the epigenetic landscape are not only the hallmark of tumor development but also contribute to the development of resistance to hormone therapy. A set of functionally related genes involved in epigenetic reprogramming are controlled by specific transcription factors (TFs). Thus, the activities of TFs mediate important mechanisms through which epigenetic enzymes and co-factors modify chromatin for the worst outcome in a site-specific manner. Furthermore, the role of epigenetic aberrations involving histone modifications is established in ovarian cancer pathogenesis. This review aims to provide insights on the role of key epigenetic determinants of response as well as resistance to the hormone therapy, the current status of research along with its limitations, and future prospects of epigenetic agents as biomarkers in early diagnosis, prognosis, and personalized treatment strategies. Finally, the possibility of small phytoestrogenic molecules in combination with immunotherapy and epi-drugs targeting ovarian cancer has been discussed.

Secretory Endometrial Adenocarcinoma: A Rare Sequelae in a Postmenopausal Woman Following Tamoxifen Therapy for Breast Cancer

The double-edged sword effect of tamoxifen therapy on the female reproductive system including the breast is quite well established. However, it is still poorly understood at the molecular level which significantly affects the management of such patients receiving it in terms of therapeutics and prognosis. An experience of an extremely rare case of secretory endometrial adenocarcinoma developing due to the adverse effect of tamoxifen used for the treatment of breast cancer in a 60-year-old woman is being described herewith so as to create awareness among the dealing clinicians about the occurrence of rare histological types of endometrial cancer after long-term tamoxifen therapy. The approach to such a case, pathogenesis, differential diagnosis, and a brief literature review is also presented.

Tamoxifen exposure induces cleft palate in mice

Cleft palate is a common birth defect in mammals, which can be caused by genetic or environmental factors, or both. Decades have witnessed that many environmental exposures during gestation extremely increase the incidence of cleft palate. Tamoxifen (TAM), a widely-used drug in treating breast cancer, has been reported to be associated with craniofacial defects including micrognathia and cleft palate in humans. However, its exact effects on the developing palate remain unclear. Here we took advantage of a mouse model to explore how TAM affects palatal development at the molecular level. We showed that excess exposure of TAM in the early embryonic stages indeed leads to cleft palate in mice. RNA-sequencing results strongly suggest the involvement of mitogen-activated protein kinase (MAPK) signalling in TAM-induced cleft palate. Interestingly, in the anterior portion of the TAM-treated palatal shelf, phosphorylated (p)-AKT and p-ERK1/2 were activated but p-p38 was inhibited, while in the posterior palate, the p-AKT increased but the levels of p-p38 and p-JNK decreased. We conclude that excess TAM exposure causes cleft palate defects in mice by regulating MAPK pathways, which implicates the importance of tightly-regulated MAPK signalling in palatal development. This study provides a basis for further exploration of the molecular aetiology of cleft palate defects caused by environmental factors and, based on our results, we would give a serious warning regarding prescription of TAM and potential cleft palate defects in animal models involving the inducible Cre-LoxP system.

Alginate based tamoxifen/metal dual core-folate decorated shell: Nanocomposite targeted therapy for breast cancer via ROS-driven NF-κB pathway modulation

Breast cancer endocrine resistance prevents unleashing full capabilities of Tamoxifen (TMX), besides TMX off-target side effects on healthy tissue. In this study, we engineered TMX nanocomposite via co-loading it on alginate-based silver nanoparticles and embedding within folic acid-polyethylene glycol surface conjugate. The coating process was done by w/o/w double emulsion method. To confirm the silver nanoparticles formation, UV spectroscopy, XRD and TEM analysis were carried out. TEM results confirmed the core-shell structure of folate targeted nanocomposite with approximate average diameter of 66 nm, the nanocomposite structures were characterized by FTIR, TGA and SEM. By comparing with the non-targeted formula, folate decorated formula had 12-folds lowered IC₅₀ value and 12.5-14-fold higher cancer cells toxic selectivity index. Also, after 4 h treatment, both fluorescence microscopic and flow cytometric analysis indicated higher intracellular accumulation of folic acid conjugated formula on MCF-7 cancer cells than the non-targeted one with 3.44-folds. The breast cancer cytotoxic effects of this metal-endocrine nanocomposite formula could be explained by the induction of reactive oxygen species (ROS), down regulation of survival oncogenic genes (BCL-2 and Survivin) and the accumulation of MCF-7 cells in G2/M phase. All these data confirm the efficiency and efficacy of the formulated nanocomposite as future treatment for breast cancer.

Correlation of the tamoxifen use with the increased risk of deep vein thrombosis and pulmonary embolism in elderly women with breast cancer: A case-control study

The association between tamoxifen use and risk of deep vein thrombosis or pulmonary embolism in women with breast cancer has been reported in the Western population. The study aimed to evaluate the association between tamoxifen use and deep vein thrombosis or pulmonary embolism in older women with breast cancer in Taiwan.We conducted a retrospective case-control study using the database of the Taiwan National Health Insurance Program. A total of 281 women subjects with breast cancer aged ≥65 years with newly diagnosed deep vein thrombosis/or pulmonary embolism from 2000 to 2011 were identified as the cases. Additionally, 907 women subjects with breast cancer aged ≥65 years without deep vein thrombosis or pulmonary embolism were randomly selected as the controls. The cases and the controls were matched with age and comorbidities. Ever use of tamoxifen was defined as subjects who had at least a prescription for tamoxifen before index date. Never use of tamoxifen was defined as subjects who never had a prescription for tamoxifen before index date. We used the multivariable logistic regression model to calculate the odds ratio (OR) and the 95% confidence interval (CI) of deep vein thrombosis or pulmonary embolism associated with tamoxifen use.After adjustment for confounding variables, the adjusted OR of deep vein thrombosis or pulmonary embolism was 1.95 for subjects with ever use of tamoxifen (95% CI 1.45, 2.62), as compared with never use of tamoxifen. In addition, atrial fibrillation (adjusted OR 3.73, 95% CI 1.89, 7.35) and chronic kidney disease (adjusted OR 1.72, 95% CI 1.06, 2.80) were also associated with deep vein thrombosis or pulmonary embolism.Tamoxifen use is associated with 1.95-fold increased odds of deep vein thrombosis or pulmonary embolism among older women with breast cancer in Taiwan.

Fbxo22-mediated KDM4B degradation determines selective estrogen receptor modulator activity in breast cancer

The agonistic/antagonistic biocharacter of selective estrogen receptor modulators (SERMs) can have therapeutic advantages, particularly in the case of premenopausal breast cancers. Although the contradictory effects of these modulators have been studied in terms of crosstalk between the estrogen receptor α (ER) and coactivator dynamics and growth factor signaling, the molecular basis of these mechanisms is still obscure. We identify a series of regulatory mechanisms controlling cofactor dynamics on ER and SERM function, whose activities require F-box protein 22 (Fbxo22). Skp1, Cullin1, F-box-containing complex (SCFFbxo22) ubiquitylated lysine demethylase 4B (KDM4B) complexed with tamoxifen-bound (TAM-bound) ER, whose degradation released steroid receptor coactivator (SRC) from ER. Depletion of Fbxo22 resulted in ER-dependent transcriptional activation via transactivation function 1 (AF1) function, even in the presence of SERMs. In living cells, TAM released SRC and KDM4B from ER in a Fbxo22-dependent manner. SRC release by TAM required Fbxo22 on almost all ER-SRC-bound enhancers and promoters. TAM failed to prevent the growth of Fbxo22-depleted, ER-positive breast cancers both in vitro and in vivo. Clinically, a low level of Fbxo22 in tumor tissues predicted a poorer outcome in ER-positive/human epidermal growth factor receptor type 2-negative (HER2-negative) breast cancers with high hazard ratios, independently of other markers such as Ki-67 and node status. We propose that the level of Fbxo22 in tumor tissues defines a new subclass of ER-positive breast cancers for which SCFFbxo22-mediated KDM4B degradation in patients can be a therapeutic target for the next generation of SERMs.

Expression of the CD59 Glycoprotein Precursor is Upregulated in an Estrogen Receptor-alpha (ER-α)-Negative and a Tamoxifen-Resistant Breast Cancer Cell Line In Vitro

Background

Breast cancer is the most prevalent cancer and the leading cause of cancer death among women. Tamoxifen (TAM) therapy is one of the most widely and successfully used endocrine treatments for estrogen receptor α (ERα)-positive breast cancer. However, resistance to TAM has been a major challenge. In addition, the mechanisms underlying endocrine resistance remain unclear. Here, we report that CD59, a phosphatidylinositol-anchored glycoprotein, is a candidate resistant gene for TAM therapies.

Material/Methods

The breast cancer cell line MCF-7, the MCF-10A cell line, and the TAM-resistant breast cancer cell line TAMR-MCF-7 were cultured. The TAMR-MCF-7 cells were transfected with CD59 siRNA and control siRNA. Then, the CD59 glycoprotein precursor expression was detected by reverse transcription-quantitative polymerase chain reaction and western blot analysis. Cell counting kit-8 and flow cytometry assay were performed to examine cell proliferation, cell apoptosis, and cell cycle. In addition, the expressions of Bax, Bcl2, cleaved-caspase-8, cleaved-caspase-6, cleaved-caspase-3, and cleaved-PARP were analyzed by western blot analysis in the TAMR-MCF-7 cells treated with CD59 siRNA.

Results

In the present study, we found that the CD59 glycoprotein precursor was aberrantly upregulated in the ERα-negative breast cancer MCF-10A cells but not the MCF-7 cells. Furthermore, the CD59 glycoprotein precursor expression was elevated in the TAM-resistant breast cancer cells. Importantly, RNAi-mediated attenuation of CD59 was sufficient to rescue the resistance to TAM in the TAMR-MCF-7 cells.

Conclusions

In summary, our results proposed a candidate biomarker for predicting TAM resistance in ERα-positive breast cancer via targeting CD59, therefore it could be a novel therapeutic option.

Pyk2 deficiency potentiates osteoblast differentiation and mineralizing activity in response to estrogen or raloxifene

Bone remodeling is controlled by the actions of bone-degrading osteoclasts and bone-forming osteoblasts (OBs). Aging and loss of estrogen after menopause affects bone mass and quality. Estrogen therapy, including selective estrogen receptor modulators (SERMs), can prevent bone loss and increase bone mineral density in post-menopausal women. Although investigations of the effects of estrogen on osteoclast activity are well advanced, the mechanism of action of estrogen on OBs is still unclear. The proline-rich tyrosine kinase 2 (Pyk2) is important for bone formation and female mice lacking Pyk2 (Pyk2-KO) exhibit elevated bone mass, increased bone formation rate and reduced osteoclast activity. Therefore, in the current study, we examined the role of estrogen signaling on the mechanism of action of Pyk2 in OBs. As expected, Pyk2-KO OBs showed significantly higher proliferation, matrix formation, and mineralization than WT OBs. In addition we found that Pyk2-KO OBs cultured in the presence of either 17β-estradiol (E2) or raloxifene, a SERM used for the treatment of post-menopausal osteoporosis, showed a further robust increase in alkaline phosphatase (ALP) activity and mineralization. We examined the possible mechanism of action and found that Pyk2 deletion promotes the proteasome-mediated degradation of estrogen receptor α (ERα), but not estrogen receptor β (ERβ). As a consequence, E2 signaling via ERβ was enhanced in Pyk2-KO OBs. In addition, we found that Pyk2 deletion and E2 stimulation had an additive effect on ERK phosphorylation, which is known to stimulate cell differentiation and survival. Our findings suggest that in the absence of Pyk2, estrogen exerts an osteogenic effect on OBs through altered ERα and ERβ signaling. Thus, targeting Pyk2, in combination with estrogen or raloxifene, may be a novel strategy for the prevention and/or treatment of bone loss diseases.

Protective Effects of 2,3,5,4'-Tetrahydroxystilbene-2-O-β-d-glucoside on Ovariectomy Induced Osteoporosis Mouse Model

2,3,5,4'-Tetrahydroxystilbene-2-O-β-d-glucoside (TSG), an active polyphenolic component of Polygonum multiflorum, exhibits many pharmacological activities including antioxidant, anti-inflammation, and anti-aging effects. A previous study demonstrated that TSG protected MC3T3-E1 cells from hydrogen peroxide (H₂O₂) induced cell damage and the inhibition of osteoblastic differentiation. However, no studies have investigated the prevention of ovariectomy-induced bone loss in mice. Therefore, we investigated the effects of TSG on bone loss in ovariectomized mice (OVX). Treatment with TSG (1 and 3 μg/g; i.p.) for six weeks positively affected body weight, uterine weight, organ weight, bone length, and weight change because of estrogen deficiency. The levels of the serum biochemical markers of calcium (Ca), inorganic phosphorus (IP), alkaline phosphatase (ALP), and total cholesterol (TCHO) decreased in the TSG-treated mice when compared with the OVX mice. Additionally, the serum bone alkaline phosphatase (BALP) levels in the TSG-treated OVX mice were significantly increased compared with the OVX mice, while the tartrate-resistant acid phosphatase (TRAP) activity was significantly reduced. Furthermore, the OVX mice treated with TSG showed a significantly reduced bone loss compared to the untreated OVX mice upon micro-computed tomography (CT) analysis. Consequently, bone destruction in osteoporotic mice as a result of ovariectomy was inhibited by the administration of TSG. These findings indicate that TSG effectively prevents bone loss in OVX mice; therefore, it can be considered as a potential therapeutic for the treatment of postmenopausal osteoporosis.

Tamoxifen usage correlates with increased risk of Parkinson's disease in older women with breast cancer: a case-control study in Taiwan

BACKGROUND AND OBJECTIVES

Little is known about the association between tamoxifen usage and risk of Parkinson's disease in women with breast cancer. The present study aimed to evaluate the association between tamoxifen usage and Parkinson's disease in older women with breast cancer in Taiwan.

METHODS

We conducted a retrospective nationwide case-control study using the database of the Taiwan National Health Insurance Program. In total, 293 female subjects with breast cancer, aged 65 years and above, who were newly diagnosed with Parkinson's disease between 2000 and 2011 were included. Additionally, 1053 female subjects with breast cancer aged 65 years and above without Parkinson's disease were randomly selected as controls. Both cases and controls were matched for age and comorbidities. Ever use of tamoxifen was defined as subjects who had at least a prescription for tamoxifen before the index date, whereas never use of tamoxifen was defined as those who never had a prescription for tamoxifen before the index date. We used the unconditional logistic regression model to calculate the odds ratio (OR) and 95% confidence interval (CI) for the association between tamoxifen usage and risk of Parkinson's disease.

RESULTS

After adjusting for confounding variables, the adjusted OR of Parkinson's disease was 3.32 for subjects with ever use of tamoxifen (95% CI, 2.50-4.43), compared with nonusers. Further analysis showed that the adjusted ORs of Parkinson's disease were 3.21 (95% CI, 2.29-4.49), 3.95 (95% CI, 2.77-5.64), and 11.4 (95% CI, 2.63-49.7) for subjects with < 2, 2-6, and ≥ 6 years of cumulative tamoxifen usage, respectively, when compared with nonusers.

CONCLUSIONS

Tamoxifen usage was associated with a 3.32-fold increase in the likelihood of having Parkinson's disease among older women with breast cancer in Taiwan.

Endocrine therapy inhibits proliferation and migration, promotes apoptosis and suppresses survivin protein expression in colorectal cancer cells

The majority of colorectal cancers (CRCs) are hormone‑dependent. Thus, endocrine therapy has become an attractive strategy to treat CRC. The aim of the present study was to investigate the inhibitory effect of combined tamoxifen (TAM) plus β‑estradiol (E2) treatment on human DLD‑1 CRC cells. The human DLD‑1 CRC cell line was treated with different concentrations of TAM, β‑estradiol, or a combination of these two agents. Cell viability was assessed using an MTT assay, while apoptosis was detected using flow cytometry analysis. Alterations in the RNA and protein levels of the apoptosis‑associated factors cyclin D1 and survivin were measured in the treated DLD‑1 cells using semi‑quantitative polymerase chain reaction (sqPCR) and western blot analyses. Alterations in cellular migration ability were monitored using a Transwell migration assay. Treatment with TAM, β‑estradiol and TAM plus β‑estradiol inhibited DLD‑1 cell viability. The flow cytometry results revealed that these drugs promoted cell apoptosis, and the Transwell migration assay results indicated that the reduction in cell migration was greater in the TAM+E2 treatment group when compared with each treatment alone. sqPCR and western blot analysis results demonstrated that TAM, E2 and a combination of the two affected survivin expression based on the drug concentration and the treatment duration; however, they demonstrated no significant effect on cyclin D1 expression. In conclusion, treatment of DLD‑1 cells with TAM, β‑estradiol, or a combination of these two drugs, inhibited cell viability and migration, promoted cell apoptosis, and reduced the mRNA and protein expression levels of survivin in a dose‑ and time‑dependent manner. These results provide novel experimental basis for hormonal adjuvant therapy for the treatment of CRC.

Label-free detection of anti-estrogen receptor alpha and its binding with estrogen receptor peptide alpha by terahertz spectroscopy

Terahertz (THz) spectroscopic techniques were employed to study the hydration shell formation around anti-estrogen receptor alpha (AER-α) and to detect the binding reaction between AER-α and estrogen receptor peptide alpha (ERP-α).

Reversal effects of Raloxifene on paclitaxel resistance in 2 MDR breast cancer cells

Raloxifene hydrochloride (RAL), one of second generation of selective estrogen receptor modulators (SERMs), is usually used in preventing osteoporosis and breast cancer. The present study evaluated whether Raloxifene might sensitize multidrug resistant (MDR) breast cancers to chemotherapies, especially in estrogen receptor negative (ER-) breast cancer. The results showed that RAL could significantly sensitize ER- MDR breast tumors to paclitaxel both in vitro and in vivo. Combination of Raloxifene could significantly enhance paclitaxel-induced cell apoptosis, G2-M arrest as well as inhibition of cell proliferation in MDR tumors. Further studies showed that the combined treatment did not alter P-glycoprotein expression but increased P-gp ATPase activity. These results suggested that raloxifene might be a valuable chemosensitizer agent for breast cancer therapy.

A combination of soy isoflavones and cello-oligosaccharides changes equol/O-desmethylangolensin production ratio and attenuates bone fragility in ovariectomized mice

We examined the cooperative effects of isoflavones and cello-oligosaccharides on daidzein metabolism and bone fragility in ovariectomized mice. Cello-oligosaccharides increased urinary equol and decreased O-desmethylangolensin. A combination of isoflavones and cello-oligosaccharides attenuated decreases in bone breaking force and stiffness caused by ovariectomy. Combination treatment with isofalvones and cello-oligosaccharides increases urinary equol/O-desmethylangolensin production ratio and prevents ovariectomy-induced abnormalities in bone strength.

Prediction of selective estrogen receptor beta agonist using open data and machine learning approach

Background

Estrogen receptors (ERs) are nuclear transcription factors that are involved in the regulation of many complex physiological processes in humans. ERs have been validated as important drug targets for the treatment of various diseases, including breast cancer, ovarian cancer, osteoporosis, and cardiovascular disease. ERs have two subtypes, ER-α and ER-β. Emerging data suggest that the development of subtype-selective ligands that specifically target ER-β could be a more optimal approach to elicit beneficial estrogen-like activities and reduce side effects.

Methods

Herein, we focused on ER-β and developed its in silico quantitative structure-activity relationship models using machine learning (ML) methods.

Results

The chemical structures and ER-β bioactivity data were extracted from public chemogenomics databases. Four types of popular fingerprint generation methods including MACCS fingerprint, PubChem fingerprint, 2D atom pairs, and Chemistry Development Kit extended fingerprint were used as descriptors. Four ML methods including Naïve Bayesian classifier, k-nearest neighbor, random forest, and support vector machine were used to train the models. The range of classification accuracies was 77.10% to 88.34%, and the range of area under the ROC (receiver operating characteristic) curve values was 0.8151 to 0.9475, evaluated by the 5-fold cross-validation. Comparison analysis suggests that both the random forest and the support vector machine are superior for the classification of selective ER-β agonists. Chemistry Development Kit extended fingerprints and MACCS fingerprint performed better in structural representation between active and inactive agonists.

Conclusion

These results demonstrate that combining the fingerprint and ML approaches leads to robust ER-β agonist prediction models, which are potentially applicable to the identification of selective ER-β agonists.

Kanamycin inhibits daidzein metabolism and abilities of the metabolites to prevent bone loss in ovariectomized mice

BACKGROUND

Daidzein is an isoflavone derived from soybeans that exerts preventive effects on bone loss in ovariectomized (OVX) animals. These effects have been correlated with increasing serum equol levels. In the present study, we investigated the effects of antibiotic intake on equol metabolism from daidzein, and the corresponding levels of bone loss in OVX mice.

METHODS

Eight-week-old female ddY mice (n = 42) were either ovariectomized (OVX) or subjected to a sham operation (sham). OVX mice were then divided into six dietary subgroups: control diet (control), 0.3 % kanamycin diet (KN), 0.1 % daidzein diet (Dz), 0.1 % daidzein and 0.0375 % kanamycin diet (Dz+KN3.75), 0.1 % daidzein and 0.075 % kanamycin diet (Dz+KN7.5), and 0.1 % daidzein and 0.3 % kanamycin diet (Dz+KN30). The mice were fed their respective diets for 4 weeks.

RESULTS

Uterine weight and femoral bone mineral density (BMD) were significantly lower in the OVX mice compared in the sham mice. No significant differences in uterine weight were observed among all OVX dietary subgroups. The Dz subgroup was found to exhibit higher plasma equol and O-desmethylangolensin (O-DMA) concentrations, as well as greater femoral BMD, compared to all other OVX subgroups. Furthermore, when compared to the Dz group, kanamycin intake decreased plasma equol and O-DMA concentrations, as well as femoral BMD in the OVX mice.

CONCLUSIONS

These results suggest that kanamycin intake inhibited the conversion of daidzein to equol and O-DMA, blocking the preventive effects of daidzein on bone loss in OVX mice. Therefore, the bone-protective effects of daidzein intake may be predominantly associated with increased plasma concentrations of either equol or O-DMA.

MicroRNA regulation of the major drug-metabolizing enzymes and related transcription factors

Identifying novel mechanisms contributing to patient variability of drug response is a major goal of personalized medicine. Epigenetic regulation of gene expression by microRNA (miRNA) impacts a broad range of cellular processes, but knowledge of its regulation of drug-metabolizing enzymes (DMEs) is more limited. This review provides an introduction to miRNA and their functionality and summarizes known miRNA regulation of DME families, including the cytochrome P450s, UDP-glucuronoslytransferases, glutathione-S-transferases, sulfotransferases and aldo-keto reductases, and the transcription factors known to be involved in DME regulation.

Antiosteoporosis Activity of New Oriental Medicine Preparation (Kyungokgo Mixed with Water Extract of Hovenia dulcis) on the Ovariectomized Mice

Protective effect of new oriental medicine (Kyungokgo mixed with water extract of Hovenia dulcis, KOGHD) was assessed on the bone loss induced mice by ovariectomy. In the in vivo experiments, antiosteoporosis effect of KOGHD was investigated using ovariectomized osteoporosis mice model. After 6 weeks of treatment, the mice were euthanized, and the effect of Kyungokgo (KOG) and KOGHD on body weight, spleen weigh, thymus weight, uterine weight, serum biochemical indicators, bone weight and length, immune cell population, bone morphometric parameters, and histological stains was observed. Our results showed that KOGHD prevented the deterioration of trabecular microarchitecture caused by ovariectomy, which were accompanied by the lower levels of bone turnover markers and immune cell population as evidenced by the inhibition of RANKL-mediated osteoclast differentiation without cytotoxic effect on bone marrow derived macrophages (BMMs). Therefore, these results suggest that the Hovenia dulcis (HD) supplementation in the KOG may also prevent and treat bone loss.

A novel therapeutic approach with Caviunin-based isoflavonoid that en routes bone marrow cells to bone formation via BMP2/Wnt-β-catenin signaling

Recently, we reported that extract of Dalbergia sissoo made from leaves and pods have antiresorptive and bone-forming effects. The positive skeletal effect attributed because of active molecules present in the extract of Dalbergia sissoo. Caviunin 7-O-[β-D-apiofuranosyl-(1-6)-β-D-glucopyranoside] (CAFG), a novel isoflavonoid show higher percentage present in the extract. Here, we show the osteogenic potential of CAFG as an alternative for anabolic therapy for the treatment of osteoporosis by stimulating bone morphogenetic protein 2 (BMP2) and Wnt/β-catenin mechanism. CAFG supplementation improved trabecular micro-architecture of the long bones, increased biomechanical strength parameters of the vertebra and femur and decreased bone turnover markers better than genistein. Oral administration of CAFG to osteopenic ovariectomized mice increased osteoprogenitor cells in the bone marrow and increased the expression of osteogenic genes in femur and show new bone formation without uterine hyperplasia. CAFG increased mRNA expression of osteoprotegerin in bone and inhibited osteoclast activation by inhibiting the expression of skeletal osteoclastogenic genes. CAFG is also an effective accelerant for chondrogenesis and has stimulatory effect on the repair of cortical bone after drill-hole injury at the tissue, cell and gene level in mouse femur. At cellular levels, CAFG stimulated osteoblast proliferation, survival and differentiation. Signal transduction inhibitors in osteoblast demonstrated involvement of p-38 mitogen-activated protein kinase pathway stimulated by BMP2 to initiate Wnt/β-catenin signaling to reduce phosphorylation of GSK3-β and subsequent nuclear accumulation of β-catenin. Osteogenic effects were abrogated by Dkk1, Wnt-receptor blocker and FH535, inhibitor of TCF-complex by reduction in β-catenin levels. CAFG modulated MSC responsiveness to BMP2, which promoted osteoblast differentiation via Wnt/β-catenin mechanism. CAFG at 1 mg/kg^/day dose in ovariectomy mice (human dose ∼0.081 mg/kg) led to enhanced bone formation, reduced bone resorption and bone turnover better than well-known phytoestrogen genistein. Owing to CAFG's inherent properties for bone, it could be positioned as a potential drug, food supplement, for postmenopausal osteoporosis and fracture repair.

Regulation of UDP-glucuronosyltransferase 1A1 expression and activity by microRNA 491-3p

The UDP-glucuronosyltransferase (UGT) 1A enzymes are involved in the phase II metabolism of many important endogenous and exogenous compounds. The nine UGT1A isoforms exhibit high interindividual differences in expression, but their epigenetic regulation is not well understood. The purpose of the present study was to examine microRNA (miRNA) regulation of hepatic UGT1A enzymes and determine whether or not that regulation impacts enzymatic activity. In silico analysis identified miRNA 491-3p (miR-491-3p) as a potential regulator of the UGT1A gene family via binding to the shared UGT1A 3'-untranslated region common to all UGT1A enzymes. Transfection of miR-491-3p mimic into HuH-7 cells significantly repressed UGT1A1 (P < 0.001), UGT1A3 (P < 0.05), and UGT1A6 (P < 0.05) mRNA levels. For UGT1A1, this repression correlated with significantly reduced metabolism of raloxifene into raloxifene-6-glucuronide (ral-6-gluc; P < 0.01) and raloxifene-4'-glucuronide (ral-4'-gluc; P < 0.01). In HuH-7 cells with repressed miR-491-3p expression, there was a significant increase (~80%; P < 0.01) in UGT1A1 mRNA and a corresponding increase in glucuronidation of raloxifene into ral-6-gluc (50%; P < 0.05) and ral-4'-gluc (22%; P < 0.01). Knockdown of endogenous miR-491-3p in HepG2 cells did not significantly alter UGT1A1 mRNA levels but did increase the formation of ral-6-gluc (50%; P < 0.05) and ral-4'-gluc (34%; P < 0.001). A significant inverse correlation between miR-491-3p expression and both UGT1A3 (P < 0.05) and UGT1A6 (P < 0.01) mRNA levels was observed in a panel of normal human liver specimens, with a significant (P < 0.05) increase in UGT1A3 and UGT1A6 mRNA levels observed in miR-491-3p nonexpressing versus expressing liver specimens. These results suggest that miR-491-3p is an important factor in regulating the expression of UGT1A enzymes in vivo.

Elevated expression of TANK-binding kinase 1 enhances tamoxifen resistance in breast cancer

Resistance to antiestrogens is one of the major challenges in breast cancer treatment. Although phosphorylation of estrogen receptor α (ERα) is an important factor in endocrine resistance, the contributions of specific kinases in endocrine resistance are still not fully understood. Here, we report that an important innate immune response kinase, the IκB kinase-related TANK-binding kinase 1 (TBK1), is a crucial determinant of resistance to tamoxifen therapies. We show that TBK1 increases ERα transcriptional activity through phosphorylation modification of ERα at the Ser-305 site. Ectopic TBK1 expression impairs the responsiveness of breast cancer cells to tamoxifen. By studying the specimens from patients with breast cancer, we find a strong positive correlation of TBK1 with ERα, ERα Ser-305, and cyclin D1. Notably, patients with tumors highly expressing TBK1 respond poorly to tamoxifen treatment and show high potential for relapse. Therefore, our findings suggest that TBK1 contributes to tamoxifen resistance in breast cancer via phosphorylation modification of ERα.

Turbo methanol extract inhibits bone resorption through regulation of T cell function

Marine organisms have bioactive potential which has tremendous pharmaceutical promise. Emerging evidence highlights the importance of the interplay between bone and the immune system of which T lymphocytes and their product act as key regulators of bone resorption. In the present investigation we have analyzed the anti-osteoporotic effect of turbo methanol extract (TME) in the reversal of bone resoprtion. Forty-two female Swiss albino mice were used and randomly assigned into sham-operated group (sham) and six ovariectomized (OVX) subgroups, i.e. OVX with vehicle (OVX) that received daily oral administration of water ad libitum; OVX with estradiol (2mg/kg/day); and OVX with different doses of TME i.e. TME 100mg/kg, TME 50mg/kg, TME 25mg/kg and TME 12.5mg/kg. Oral administration of TME or estradiol started on the second week after ovariectomy for a period of 4weeks. We observed that the administration of TME increased the trabeculation in tibia and reduced the atrophy in the uterus. TME significantly decreased the serum alkaline phosphatase (ALP) and acid phosphatase (ACP) activity in OVX mice. Micro CT analysis revealed that the TME administration preserved the bone volume, connectivity density, trabecular number, trabecular thickness and trabecular separation in OVX mice. Bone mineralization was measured in different groups of mice by Raman spectroscopy. Reversal of bone resorption was observed in TME treated group of mice. To further investigate the mechanism of action of TME, we analyzed the T lymphocyte proliferation and profiles of cytokine TNFα and sRANKL in TME treated ovariectomized mice. Decrease in the elevation of T cell subsets was observed after the supplementation with TME. The extract significantly lowered the T cell proliferation responses to mitogens, phorbol 12-myristate 13-acetate (PMA) and ionomycin (Io) and phytohemagglutinin (PHA). A marked reduction in TNFα and sRANKL secretion in serum and TNFα in cell free supernatants of activated T lymphocytes was observed upon TME administration. TME could significantly inhibit the in vitro osteoclastogenesis and the bone resorption observed using artificial calcium coated slides. Collectively, these results indicate that TME has the potential to inhibit bone resorption and may prove to be a potential candidate for the development of an anti-osteoporosis drug.

Predicting disease risk using bootstrap ranking and classification algorithms

Genome-wide association studies (GWAS) are widely used to search for genetic loci that underlie human disease. Another goal is to predict disease risk for different individuals given their genetic sequence. Such predictions could either be used as a “black box” in order to promote changes in life-style and screening for early diagnosis, or as a model that can be studied to better understand the mechanism of the disease. Current methods for risk prediction typically rank single nucleotide polymorphisms (SNPs) by the p-value of their association with the disease, and use the top-associated SNPs as input to a classification algorithm. However, the predictive power of such methods is relatively poor. To improve the predictive power, we devised BootRank, which uses bootstrapping in order to obtain a robust prioritization of SNPs for use in predictive models. We show that BootRank improves the ability to predict disease risk of unseen individuals in the Wellcome Trust Case Control Consortium (WTCCC) data and results in a more robust set of SNPs and a larger number of enriched pathways being associated with the different diseases. Finally, we show that combining BootRank with seven different classification algorithms improves performance compared to previous studies that used the WTCCC data. Notably, diseases for which BootRank results in the largest improvements were recently shown to have more heritability than previously thought, likely due to contributions from variants with low minimum allele frequency (MAF), suggesting that BootRank can be beneficial in cases where SNPs affecting the disease are poorly tagged or have low MAF. Overall, our results show that improving disease risk prediction from genotypic information may be a tangible goal, with potential implications for personalized disease screening and treatment.

Genome-wide association studies are widely used to search for genetic loci that underlie human disease. Another goal is to predict disease risk for different individuals given their genetic sequence. Such predictions could either be used as a “black box” in order to promote changes in life-style and screening for early diagnosis, or as a model that can be studied to better understand the mechanism of the disease. Current methods for risk prediction have relatively poor performance, with one possible explanation being the fact they rely on a noisy ranking of genetic variants given to them as input. To improve the predictive power, we devised BootRank, a ranking method less sensitive to noise. We show that BootRank improves the ability to predict disease risk of unseen individuals in the Wellcome Trust Case Control Consortium (WTCCC) data, and that combining BootRank with different classification algorithms improves performance compared to previous studies that used these data. Overall, our results show that improving disease risk prediction from genotypic information may be a tangible goal, with potential implications for personalized disease screening and treatment.

Effects of herbal supplements on the bioactivation of chemotherapeutic agents

OBJECTIVES

The aim of this study was to investigate the impact of commercially available, over-the-counter herbal supplements (St John's wort, black cohosh and ginger root extract) on the metabolic activation of tamoxifen and irinotecan.

METHODS

Co-incubation of each drug and supplement combination over a range of concentrations was conducted in human liver microsomes and the decrease in the rate of active metabolite formation was monitored using high-performance liquid chromatography tandem mass spectrometry. Data was analysed using non-linear regression analysis and Dixon plots to determine the dominant mechanism of inhibition and to estimate the Ki and IC50 values of the commercial supplements.

KEY FINDINGS

The data suggest that black cohosh was the strongest inhibitor tested in this study for both CYP450 and carboxyesterase mediated biotransformation of tamoxifen and irinotecan, respectively, to their active metabolites. St John's wort was a stronger inhibitor compared with ginger root extract for tamoxifen (CYP mediated pathway), while ginger root extract was a stronger inhibitor compared with St John's wort for the carboxyesterase mediated pathway.

CONCLUSIONS

Commercially available supplements are widely used by patients and their potential impact on the efficacy of the chemotherapy is often unknown. The clinical significance of these results needs to be evaluated in a comprehensive clinical trial.

Isoflavone metabolism and bone-sparing effects of daidzein-metabolites

Several dietary phytochemicals exhibit anti-oxidative, anti-inflammatory and anti-osteoporotic activities relevant to prevention of chronic diseases, including lifestyle-related diseases. Soybean isoflavones are similar in structure to estrogen and have received considerable attention as potential alternatives to hormone replacement therapy. Daidzein, a major isoflavone found in soybean, is metabolized to equol by intestinal microflora; this metabolite exhibits stronger estrogenic activity than daidzein. Recent studies suggest that the clinical effectiveness of isoflavones might be due to their ability to produce equol in the gut. This review focused on the metabolic pathway of equol and possible bioactivities of equol and O-desmethylangolensin, another metabolite of daidzein, with regard to bone metabolism and the status of intestinal microflora. Furthermore, we considered risk-benefit analyses of isoflavones and their metabolites.

Effects of toremifene versus tamoxifen on breast cancer patients: a meta-analysis

Toremifene and tamoxifen are both selective estrogen receptor modulators used in the treatment of breast cancer patients. Therefore, we carried out a meta-analysis to achieve a more precise evaluation of the effects of toremifene versus tamoxifen on breast cancer patients, including the efficacy and safety, and the effects on the uterus, lipids, and bone. Comprehensive literature searches were conducted using the electronic databases and reference lists to include randomized controlled trials (RCTs) that compared toremifene with tamoxifen for breast cancer patients. Two reviewers independently selected studies and abstracted data. Data were analyzed by Review Manager, version 5.0. Twenty-three trials (7242 patients) were included. For early stage breast cancer, toremifene was associated with higher 5-year survival rates (OR 1.25, 95 % CI 1.04, 1.50), more vaginal discharge (OR 1. 32, 95 % CI 1.01, 1.73), a greater decrease in serum triglyceride levels (SMD -1.01, 95 % CI -1.89, -0.14), a smaller decrease in LDL cholesterol levels (SMD 0.45, 95 % CI 0.07, 0.84) and in bone mineral density in Ward's triangle (SMD -0.36, 95 % CI -0.71, -0.01), and a greater increase in HDL cholesterol levels (SMD 0.43, 95 % CI 0.08, 0.77) than tamoxifen. For advanced breast cancer patients, toremifene was associated with more vaginal bleeding (OR 0.45, 95 % CI 0.26, 0.80) and a greater decrease in serum triglyceride levels (SMD -1.15, 95 % CI -1.90, -0.39) than tamoxifen. Available evidence showed that toremifene could be an alternative option to tamoxifen for both early and advanced breast cancer patients. However, the methodological quality of the included studies was low. More rigorous RCTs are needed to confirm the results of this meta-analysis in the future.

Cooperating transcription factors mediate the function of estrogen receptor

Estrogen receptor (ER) is a hormone-regulated transcription factor that controls cell division and differentiation in the ovary, breast, and uterus. The expression of ER is a common feature of the majority of breast cancers, which is used as a therapeutic target. Recent genetic studies have shown that ER binding occurs in regions distant to the promoters of estrogen target genes. These studies have also demonstrated that ER binding is accompanied with the binding of other transcription factors, which regulate the function of ER and response to anti-estrogen therapies. In this review, we explain how these factors influence the interaction of ER to chromatin and their cooperation for ER transcriptional activity. Moreover, we describe how the expression of these factors dictates the response to anti-estrogen therapies. Finally, we discuss how cytoplasmatic signaling pathways may modulate the function of ER and its cooperating transcription factors.

Estradiol receptors in breast cancer cells: associated co-factors as targets for new therapeutic approaches

Estrogen receptors α (ERα) and β (ERβ) are nuclear receptors which transduce estradiol (E2) response in many tissues including the mammary gland and breast cancers (BC). They activate or inhibit specific genes involved in cell cycle progression and cell survival through multiple enzyme activities leading to malignant transformation. Hormone therapy (antiestrogens (AEs) and aromatase inhibitors (AIs) have been widely used to block the mitogenic action of E2 in patients with ER-positive BC. ERs act in concert with numerous other proteins outside and inside the nucleus where co-activators such as histone modifying enzymes help reaching optimum gene activation. Moreover, E2-mediated gene regulation can occur through ERs located at the plasma membrane or G protein-coupled estrogen receptor (GPER), triggering protein kinase signaling cascades. Classical AEs as well as AIs are inefficient to block the cascades of events emanating from the membrane and from E2 binding to GPER, leading patients to escape anti-hormone treatments and hormone therapy resistance. Many pathways are involved in resistance, mostly resulting from over-expression of growth factor membrane receptors, in particular the HER2/ErbB2 which can be inhibited by specific antibodies or tyrosine kinases inhibitors. Together with the Hsp90 molecular chaperone machinery, a complex interplay between ERs, co-activators, co-repressors and growth factor-activated membrane pathways represents potent targets which warrant to be manipulated alone and in combination to designing novel therapies. The discovery of new potential targets arising from micro array studies gives the opportunity to activate or inhibit different new ER-modulating effectors for innovative therapeutic interventions.

[Hormone therapy and breast cancer]

The nuclear estrogen receptors (ER) are the major targets for endocrine treatment of hormone-dependent breast cancers. Hormone therapy blocked endogenous estrogen activation of ER, either by competitive inhibition of endogenous estrogens (selective estrogen receptor modulators - SERM or selective estrogen receptor down regulators - SERD) or by inhibition of estrogen synthesis (aromatase inhibitors) from adrenal androgens in post-menopausal women. The efficacy of these treatments has been shown on large series of breast cancer patients. However de novo or acquired resistance to treatment occurs. The better knowledge of the mechanism of action of such treatment may help to better understand them, and also for the determinism of adverse side effects of the different class of molecules.

17β-estradiol and tamoxifen prevent gastric cancer by modulating leukocyte recruitment and oncogenic pathways in Helicobacter pylori-infected INS-GAS male mice

Helicobacter pylori infection promotes male predominant gastric adenocarcinoma in humans. Estrogens reduce gastric cancer risk and previous studies showed that prophylactic 17β-estradiol (E2) in INS-GAS mice decreases H. pylori-induced carcinogenesis. We examined the effect of E2 and tamoxifen (TAM) on H. pylori-induced gastric cancer in male and female INS-GAS mice. After confirming robust gastric pathology at 16 weeks postinfection (WPI), mice were implanted with E2, TAM, both E2 and TAM, or placebo pellets for 12 weeks. At 28 WPI, gastric histopathology, gene expression, and immune cell infiltration were evaluated and serum inflammatory cytokines measured. After treatment, no gastric cancer was observed in H. pylori-infected males receiving E2 and/or TAM, whereas 40% of infected untreated males developed gastric cancer. E2, TAM, and their combination significantly reduced gastric precancerous lesions in infected males compared with infected untreated males (P < 0.001, 0.01, and 0.01, respectively). However, TAM did not alter female pathology regardless of infection status. Differentially expressed genes from males treated with E2 or TAM (n = 363 and n = 144, Q < 0.05) associated highly with cancer and cellular movement, indicating overlapping pathways in the reduction of gastric lesions. E2 or TAM deregulated genes associated with metastasis (PLAUR and MMP10) and Wnt inhibition (FZD6 and SFRP2). Compared with controls, E2 decreased gastric mRNA (Q < 0.05) and serum levels (P < 0.05) of CXCL1, a neutrophil chemokine, leading to decreased neutrophil infiltration (P < 0.01). Prevention of H. pylori-induced gastric cancer by E2 and TAM may be mediated by estrogen signaling and is associated with decreased CXCL1, decreased neutrophil counts, and downregulation of oncogenic pathways.

Hormonal factors and risks of esophageal squamous cell carcinoma and adenocarcinoma in postmenopausal women

The incidences of esophageal adenocarcinoma and squamous cell carcinoma (SCC) are higher in males than in females. We investigated whether female-related hormonal factors are associated with risks of these two types of esophageal cancer. We examined the association between use of hormone therapy (HT) and the risks of esophageal adenocarcinoma and SCC in postmenopausal women enrolled in the Women's Health Initiative (WHI) clinical trials and observational studies. Twenty-three esophageal adenocarcinoma and 34 esophageal SCC cases were confirmed among the 161,080 participants, after a median of 11.82 years of follow-up. Risk of esophageal SCC was lower among HT users (past users: HR = 0.25, 95% CI: 0.06-1.10 in 2 cases; current users: HR = 0.41, 95% CI: 0.18-0.94 in 9 cases). A decreased esophageal SCC risk was observed for current users of estrogen plus progestin (E+P) therapy (HR = 0.25, 95% CI: 0.07-0.86 in 3 cases) but not for current users of estrogen-only therapy (HR = 0.96, 95% CI: 0.28-3.29 in 6 cases). No association was observed between the use of HT and the risk of esophageal adenocarcinoma. No other reproductive or hormonal factors were significantly associated with the risk of either SCC or adenocarcinoma. Current use of E+P therapy was found to be associated with a decreased risk of esophageal SCC, but no association was observed with esophageal adenocarcinoma. To provide more definitive evidence, a pooled analysis of all available studies or a much larger study would be needed.

Genetic rescue of nonclassical ERα signaling normalizes energy balance in obese Erα-null mutant mice

In addition to its role in reproduction, estradiol-17β is critical to the regulation of energy balance and body weight. Estrogen receptor α-null (Erα-/-) mutant mice develop an obese state characterized by decreased energy expenditure, decreased locomotion, increased adiposity, altered glucose homeostasis, and hyperleptinemia. Such features are reminiscent of the propensity of postmenopausal women to develop obesity and type 2 diabetes. The mechanisms by which ERα signaling maintains normal energy balance, however, have remained unclear. Here we used knockin mice that express mutant ERα that can only signal through the noncanonical pathway to assess the role of nonclassical ERα signaling in energy homeostasis. In these mice, we found that nonclassical ERα signaling restored metabolic parameters dysregulated in Erα-/- mutant mice to normal or near-normal values. The rescue of body weight and metabolic function by nonclassical ERα signaling was mediated by normalization of energy expenditure, including voluntary locomotor activity. These findings indicate that nonclassical ERα signaling mediates major effects of estradiol-17β on energy balance, raising the possibility that selective ERα agonists may be developed to reduce the risks of obesity and metabolic disturbances in postmenopausal women.

Isoflavones suppress cyclic adenosine 3',5'-monophosphate regulatory element-mediated transcription in osteoblastic cell line

Soy isoflavones have been implicated to exert benefit on bone loss in postmenopausal women. Isoflavones can induce estrogen response element-mediated transcription in osteoblastic cells. In the present study, we investigate whether isoflavones genistein and daidzein regulate target gene transcription through cAMP regulatory element (CRE) in osteoblastic cells. It was found that 17β-estradiol (E(2)), genistein and daidzein suppressed the transcriptional activity of CRE-luciferase reporter gene in human osteoblastic cell line MG-63 cells. E(2) and genistein but not daidzein inhibited the cAMP analogue 8-Br cAMP-induced transcription of CRE reporter gene. Both genistein and E(2) inhibited basal and cAMP-induced mRNA levels of endogenous estrogen responsive genes containing CRE/CRE-like elements in their promoter regions, including interleukin (IL) 8 and serum- and glucocorticoid-inducible kinase 1 (SGK1). Daidzein inhibited basal and cAMP-induced IL-8, but not SGK1 mRNA expression. The inhibitory effects of E(2), genistein and daidzein on CRE-mediated transcription activity were enhanced by estrogen receptor (ER) α overexpression in MG-63 cells, which could be blocked by nonselective ER antagonists ICI182780, 4-OH tamoxifen and specific ERα antagonist MPP. Genistein and daidzein, but not E(2) treatment, caused a significant decrease in CRE-mediated transcription activity in ERβ-transfected MG-63 cells, which could be blocked by ICI182780, 4-OH tamoxifen and the selective ERβ antagonist (R,R)-5,11-diethyl-5.6,11,12-tetradro-2,8-chrysenediol. Our results indicate that isoflavones genistein and daidzein might modulate bone remodeling through ERs by regulating target gene expression through the CRE motifs.

Two good choices to prevent breast cancer: great taste, less filling

An important report in this issue of the journal by Vogel et al. (beginning on p. 696) discloses long-term follow-up data of the Study of Tamoxifen and Raloxifene (STAR) showing persisting strong effects of both drugs in preventing invasive and noninvasive breast cancer after drugs were stopped in 2006. In addition, safety improved with longer follow-up (median of 81 months versus 47 months for the initial report). For 12 years, the public has avoided Food and Drug Administration-approved tamoxifen or raloxifene for breast cancer risk reduction; it is time to reemphasize the great preventive benefit of these agents to the public.

Randomized phase III trial of tamoxifen versus thalidomide in women with biochemical-recurrent-only epithelial ovarian, fallopian tube or primary peritoneal carcinoma after a complete response to first-line platinum/taxane chemotherapy with an evaluation of serum vascular endothelial growth factor (VEGF): A Gynecologic Oncology Group Study

PURPOSE

To compare progression-free survival (PFS), overall survival (OS) and toxicities of thalidomide versus tamoxifen and to evaluate serum vascular endothelial growth factor (VEGF) in biochemical-recurrent epithelial ovarian cancer, primary peritoneal cancer or fallopian tube carcinoma (EOC/PPC/FTC).

METHODS

Biochemical recurrence was defined as a rising CA-125 exceeding twice the upper limit of normal without evidence of disease as defined by RECIST 1.0 criteria. Women with FIGO stages III and IV, histologically confirmed EOC/PPC/FTC who were free of disease following first-line chemotherapy were randomized to oral thalidomide 200mg daily with escalation to a maximum of 400 mg or tamoxifen 20mg orally twice daily for up to 1 year, progression or adverse effect prohibited further treatment. VEGF was quantified by ELISA in pre and post-treatment serum.

RESULTS

Of the 139 women randomized, 138 were eligible. Interim analysis showed that thalidomide did not reduce the recurrence rate relative to tamoxifen, and the trial was closed. Thalidomide versus tamoxifen was associated with a similar risk of progression (HR = 1.31, 95% confidence interval [CI] = 0.93-1.85), an increased risk of death (HR = 1.76, 95% CI = 1.16-2.68) and more grades 3 and 4 toxicities (55% versus 3%). The most common grades 3 and 4 toxicities were constitutional (12%), somnolence (12%), pulmonary (9%), venous thromboembolism (VTE) (6%) and peripheral neurologic (6%) for thalidomide, with VTE (1.4%) and gastrointestinal (1.4%) for tamoxifen. Serum VEGF was not associated with clinical characteristics, treatment, PFS or OS.

CONCLUSION

Thalidomide was not more effective than tamoxifen in delaying recurrence or death but was more toxic. VEGF was not prognostic in this cohort.

Effects of bazedoxifene/conjugated estrogens on quality of life in postmenopausal women with symptoms of vulvar/vaginal atrophy

OBJECTIVE

To evaluate the effects of the tissue selective estrogen complex (TSEC) pairing bazedoxifene (BZA) with conjugated estrogens (CE) on sexual function and quality of life in postmenopausal women.

METHODS

In this 12-week, double-blind, placebo-controlled study, postmenopausal, non-hysterectomized women (n = 652) with symptoms of moderate to severe vulvar/vaginal atrophy were randomized to once-daily treatment with BZA 20 mg/CE 0.45 or 0.625 mg, BZA 20 mg, or placebo. The Arizona Sexual Experiences (ASEX) Scale, Menopause-Specific Quality of Life (MENQOL) questionnaire, and Menopause Symptoms Treatment Satisfaction Questionnaire (MS-TSQ) were secondary measures used to assess the effects of BZA/CE on sexual function, menopausal symptoms, and satisfaction with treatment, respectively.

RESULTS

At week 12, both BZA/CE doses were associated with significant improvement in ease of lubrication score from baseline compared with placebo (p < 0.05) on the ASEX scale, although there was no difference in the change in total score. The MENQOL questionnaire results at week 12 showed significant improvements in vasomotor function, sexual function and total scores with both BZA/CE doses vs. placebo or BZA 20 mg (p < 0.001). The MS-TSQ results showed that BZA/CE-treated subjects reported significantly greater overall satisfaction with treatment, as well as satisfaction with control of hot flushes during the day and night, effect on quality of sleep, and effect on mood or emotions, compared with subjects treated with placebo or BZA 20 mg (all p < 0.05).

CONCLUSION

Treatment with BZA/CE for 12 weeks was shown to significantly improve sexual function and quality-of-life measures in symptomatic postmenopausal women.

Risk of Parkinson's disease after tamoxifen treatment

Background

Women have a reduced risk of developing Parkinson's disease (PD) compared with age-matched men. Neuro-protective effects of estrogen potentially explain this difference. Tamoxifen, commonly used in breast cancer treatment, may interfere with the protective effects of estrogen and increase risk of PD. We compared the rate of PD in Danish breast cancer patients treated with tamoxifen to the rate among those not treated with tamoxifen.

Methods

A cohort of 15,419 breast cancer patients identified from the Danish Breast Cancer Collaborative Group database was linked to the National Registry of Patients to identify PD diagnoses. Overall risk and rate of PD following identification into the study was compared between patients treated with tamoxifen as adjuvant hormonal therapy and patients not receiving tamoxifen. Time-dependent effects of tamoxifen treatment on PD rate were examined to estimate the likely induction period for tamoxifen.

Results

In total, 35 cases of PD were identified among the 15,419 breast cancer patients. No overall effect of tamoxifen on rate of PD was observed (HR = 1.3, 95% CI: 0.64-2.5), but a PD hazard ratio of 5.1 (95% CI: 1.0-25) was seen four to six years following initiation of tamoxifen treatment.

Conclusions

These results provide evidence that the neuro-protective properties of estrogen against PD occurrence may be disrupted by tamoxifen therapy. Tamoxifen treatments may be associated with an increased rate of PD; however these effects act after four years, are of limited duration, and the adverse effect is overwhelmed by the protection against breast recurrence conferred by tamoxifen therapy.