Differential actions of estrogen and SERMs in regulation of the actin cytoskeleton of endometrial cells

Metastases and Recurrence Risk Factors in Endometrial Cancer-The Role of Selected Molecular Changes, Hormonal Factors, Diagnostic Methods and Surgery Procedures

The presence of metastatic endometrial cancer (EC) is a key problem in treatment failure associated with reduced overall survival rates. The most common metastatic location is the pelvic lymph nodes, and the least common is the brain. The presence of metastasis depends on many factors, including the molecular profile of cancer (according to the TCGA-Genome Atlas), the activity of certain hormones (estrogen, prolactin), and pro-inflammatory adipocytokines. Additionally, an altered expression of microRNAs affecting the regulation of numerous genes is also related to the spread of cancer. This paper also discusses the value of imaging methods in detecting metastases; the primary role is attributed to the standard transvaginal USG with the tumor-free distance (uTFD) option. The influence of diagnostic and therapeutic methods on EC spread is also described. Hysteroscopy, according to the analysis discussed above, may increase the risk of metastases through a fluid medium, mainly performed in advanced stages of EC. According to another analysis, laparoscopic hysterectomy performed with particular attention to avoiding risky procedures (trocar flushing, tissue traumatization, preserving a margin of normal tissue) was not found to increase the risk of EC dissemination.

Current and Emerging Treatment Options for Uterine Fibroids

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

Allele-Specific Gene Regulation, Phenotypes, and Therapeutic Vulnerabilities in Estrogen Receptor Alpha-Mutant Endometrial Cancer

Activating estrogen receptor alpha (ER; also known as ESR1) mutations are present in primary endometrial and metastatic breast cancers, promoting estrogen-independent activation of the receptor. Functional characterizations in breast cancer have established unique molecular and phenotypic consequences of the receptor, yet the impact of ER mutations in endometrial cancer has not been fully explored. In this study, we used CRISPR-Cas9 to model the clinically prevalent ER-Y537S mutation and compared results with ER-D538G to discover allele-specific differences between ER mutations in endometrial cancer. We found that constitutive activity of mutant ER resulted in changes in the expression of thousands of genes, stemming from combined alterations to ER binding and chromatin accessibility. The unique gene expression programs resulted in ER-mutant cells developing increased cancer-associated phenotypes, including migration, invasion, anchorage-independent growth, and growth in vivo. To uncover potential treatment strategies, we identified ER-associated proteins via Rapid Immunoprecipitation and Mass Spectrometry of Endogenous Proteins and interrogated two candidates, CDK9 and NCOA3. Inhibition of these regulatory proteins resulted in decreased growth and migration, representing potential novel treatment strategies for ER-mutant endometrial cancer.

IMPLICATIONS

This study provides insight into mutant ER activity in endometrial cancer and identifies potential therapies for women with ER-mutant endometrial cancer.

Endometriosis of the Cervix: A Rare Clinical Case with the Possibility of Comparing the Eutopic and Ectopic Endometrium at the Cellular Level

Endometriosis of the cervix is a rare form of genital endometriosis, which is characterized by the appearance of tissue on the vaginal part of the cervix, similar to the tissue of the mucous membrane of the uterine cavity. We describe a clinical case in which we compared the content of cytoskeletal proteins, H3 histone modifications and DNA methylation (total and 5-hydroxymethylcytosine content) in the eutopic endometrium and in tissue from endometriosis foci on the cervix. The patient had elevated levels of estradiol, interleukin-1β and interleukin-8. At the cellular level, the content of tubulin and the marker of stable microtubules were reduced in the ectopic endometrium (by 45% and 37%, p < 0.05, respectively), but the alpha-actinin-1 content was increased (by 75%, p < 0.05) with an increase in the expression of its gene. At the same time, the total level of DNA methylation in the endometriotic focus was reduced by more than 2 times with the accumulation of the intermediate product 5-hydroxymethylcytosine (the content increased by more than 3 times), probably due to an increase in the content of tet methylcytosine dioxygenase 1 (more than 4 times).

Western blot normalization: Time to choose a proper loading control seriously

Recent research has questioned the validity of housekeeping proteins in Western blot. Our present study proposed new ideas for Western blot normalization that improved the reproducibility of scientific research. We used the Gene Expression Omnibus (GEO) database and the web tool GEO2R to exclude unstable housekeeping genes quickly. In ischemic heart tissues, actin and tubulin changed significantly, whereas no statistically significant changes were observed in the expression of genes relative to glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Besides, the reliability of GAPDH was further examined by Western blot. Additionally, unstable housekeeping genes were found in other animal models of cardiovascular medicine. We also found that sodium dodecyl sulfate and temperature significantly impacted the results of Ponceau S staining. Membranes stained with Ponceau S after immunodetection could avoid this interference, and the coefficients of variation for post-immunodetection staining are lower than those produced by GAPDH immunodetection. Overall, we described a new use of differential gene expression analysis and proposed a modified Ponceau S staining method, which provided researchers with a proper loading control for Western blot and hence could improve reproducibility in research.

Estrogen Enhances Dendrite Spine Function and Recovers Deficits in Neuroplasticity in the prpTDP-43A315T Mouse Model of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) attacks the corticomotor system, with motor cortex function affected early in disease. Younger females have a lower relative risk of succumbing to ALS than males and older females, implicating a role for female sex hormones in disease progression. However, the mechanisms driving this dimorphic incidence are still largely unknown. We endeavoured to determine if estrogen mitigates disease progression and pathogenesis, focussing upon the dendritic spine as a site of action. Using two-photon live imaging we identify, in the prpTDP-43A315T mouse model of ALS, that dendritic spines in the male motor cortex have a reduced capacity for remodelling than their wild-type controls. In contrast, females show higher capacity for remodelling, with peak plasticity corresponding to highest estrogen levels during the estrous cycle. Estrogen manipulation through ovariectomies and estrogen replacement with 17β estradiol in vivo was found to significantly alter spine density and mitigate disease severity. Collectively, these findings reveal that synpatic plasticity is reduced in ALS, which can be amelioriated with estrogen, in conjuction with improved disease outcomes.

Expression of ezrin protein and phosphorylated ezrin in pelvic endometriotic lesions

OBJECTIVE

To evaluate the expression of Ezrin and Phosphorylated Ezrin (Phospho-Ezrin) in endometriosis lesions and its relation to the menstrual cycle phase, stage of endometriosis, histological classification, and clinical symptoms.

MATERIAL AND METHODS

The authors conducted a retrospective study, with endometriotic lesions collected from women with endometriosis (n = 57) who underwent laparoscopy from 2017 to 2018. The expression of Ezrin and Phosphorylated Ezrin proteins was analyzed by immunohistochemistry.

RESULTS

All the endometriotic lesions contained immunostaining for Ezrin in the glands. Phosphorylated Ezrin was expressed in the stroma of all endometriotic lesions. There was no difference in the Ezrin and Phosphorylated Ezrin's expression in the retrocervical, ovarian, superficial, and intestinal lesions in the same patient. Dysmenorrhea, dyspareunia, acyclic pain, infertility, and dysuria were similar in the three groups of Ezrin staining. There was an inversely proportional relationship between severe dyschezia and Ezrin's intensity, being 66.7% of Ezrin 1 (weak intensity), 36.7 Ezrin 2 (moderate intensity), and 10.0% of Ezrin 3 (p = 0.013). Regarding Phospho-Ezrin there wasn't a significant difference between all the analyzed variables. Histological classification and menstrual cycle phase had also no significant difference between Ezrin and Phospho-Ezrin immunostaining.

CONCLUSION

Ezrin protein and Phospho-Ezrin can be considered important markers to elucidate the mechanisms related to migration and attachment of endometriotic lesions. It is still unclear if Ezrin and Phospho-Ezrin are a cause or consequence of endometriosis. Further studies comparing different types of lesions and eutopic endometrium are necessary to elucidate the role of these proteins in the pathogenesis of endometriosis.

Organization of the Cytoskeleton in Ectopic Foci of the Endometrium with Rare Localization

(1) Background: Endometriosis is a common pathology of the female reproductive system, often accompanied by pain and decreased fertility. However, its pathogenesis has not been sufficiently studied regarding the role of the cytoskeleton. In this study, we describe two clinical cases involving rare localization of extragenital endometriosis (umbilicus) and compare them with genital endometriosis of different localization (ovaries and uterus), as well as eutopic endometrium obtained with separate diagnostic curettage without confirmed pathology. (2) Methods: The relative content of actin and tubulin cytoskeleton proteins was determined by Western blotting, and the expression of genes encoding these proteins was determined by RT-PCR in the obtained intraoperative biopsies. The content of 5hmC was estimated by dot blot experiments, and the methylase/demethylase and acetylase/deacetylase contents were determined. (3) Results: The obtained results indicate that the content of the actin-binding protein alpha-actinin1 significantly increased (p < 0.05) in the groups with endometriosis, and this increase was most pronounced in patients with umbilical endometriosis. In addition, both the mRNA content of the ACTN1 gene and 5hmC content increased. It can be assumed that the increase in 5hmC is associated with a decrease in the TET3 demethylase content. Moreover, in the groups with extragenital endometriosis, alpha- and beta-tubulin content was decreased (p < 0.05) compared to the control levels. (4) Conclusions: In analyzing the results, further distance of ectopic endometrial foci from the eutopic localization may be associated with an increase in the content of alpha-actinin1, probably due to an increase in the expression of its gene and an increase in migration potential. In this case, a favorable prognosis can be explained by a decrease in tubulin content and, consequently, a decrease in the rate of cell division.

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.

Estradiol Induces Epithelial to Mesenchymal Transition of Human Glioblastoma Cells

The mesenchymal phenotype of glioblastoma multiforme (GBM), the most frequent and malignant brain tumor, is associated with the worst prognosis. The epithelial–mesenchymal transition (EMT) is a cell plasticity mechanism involved in GBM malignancy. In this study, we determined 17β-estradiol (E2)-induced EMT by changes in cell morphology, expression of EMT markers, and cell migration and invasion assays in human GBM-derived cell lines. E2 (10 nM) modified the shape and size of GBM cells due to a reorganization of actin filaments. We evaluated EMT markers expression by RT-qPCR, Western blot, and immunofluorescence.We found that E2 upregulated the expression of the mesenchymal markers, vimentin, and N-cadherin. Scratch and transwell assays showed that E2 increased migration and invasion of GBM cells. The estrogen receptor-α (ER-α)-selective agonist 4,4’,4’’-(4-propyl-[1H]-pyrazole-1,3,5-triyl)trisphenol (PPT, 10 nM) affected similarly to E2 in terms of the expression of EMT markers and cell migration, and the treatment with the ER-α antagonist methyl-piperidino-pyrazole (MPP, 1 μM) blocked E2 and PPT effects. ER-β-selective agonist diarylpropionitrile (DNP, 10 nM) and antagonist 4-[2-phenyl-5,7-bis(trifluoromethyl)pyrazole[1,5-a]pyrimidin-3-yl]phenol (PHTPP, 1 μM) showed no effects on EMT marker expression. These data suggest that E2 induces EMT activation through ER-α in human GBM-derived cells.

Ezrin T567 phosphorylation regulates migration and invasion of ectopic endometrial stromal cells by changing actin cytoskeleton

AIMS

The enhanced ability of endometrial cell migration and invasion is the foundation for formation of ectopic lesions in endometriosis. Ezrin has been reported to regulate cell motility by remodeling the cytoskeleton. However, little is known about the mechanisms through which ezrin remodels the cytoskeleton and cell structure to promote cell motility in endometriosis.

METHODS

In our study, expression and distribution of ezrin, and Rho pathway were detected through immunohistochemical analysis. The effects of inhibiting ezrin T567 phosphorylation on Rho signaling pathway and cytoskeleton were investigated through western blot, transmission electron microscopy and immunofluorescence analysis.

KEY FINDINGS

We found that the expression of ezrin and Rho pathway was higher in ectopic endometrium. NSC305787 inhibited the phosphorylation of ezrin T567, resulting in decreased expression of Rho pathway and reduced filopodia formation in ectopic endometrial stromal cells.

SIGNIFICANCE

Taken together, our study suggested that ezrin T567 phosphorylation modulated migration and invasion of ectopic ESCs through actin reconstructions, which may serve as a novel therapeutic target in ovarian endometriosis.

Structural plasticity of the hippocampus in response to estrogens in female rodents

It is well established that estrogens affect neuroplasticity in a number of brain regions. In particular, estrogens modulate and mediate spine and synapse formation as well as neurogenesis in the hippocampal formation. In this review, we discuss current research exploring the effects of estrogens on dendritic spine plasticity and neurogenesis with a focus on the modulating factors of sex, age, and pregnancy. Hormone levels, including those of estrogens, fluctuate widely across the lifespan from early life to puberty, through adulthood and into old age, as well as with pregnancy and parturition. Dendritic spine formation and modulation are altered both by rapid (likely non-genomic) and classical (genomic) actions of estrogens and have been suggested to play a role in the effects of estrogens on learning and memory. Neurogenesis in the hippocampus is influenced by age, the estrous cycle, pregnancy, and parity in female rodents. Furthermore, sex differences exist in hippocampal cellular and molecular responses to estrogens and are briefly discussed throughout. Understanding how structural plasticity in the hippocampus is affected by estrogens and how these effects can influence function and be influenced by other factors, such as experience and sex, is critical and can inform future treatments in conditions involving the hippocampus.

Use of the REVERT® total protein stain as a loading control demonstrates significant benefits over the use of housekeeping proteins when analyzing brain homogenates by Western blot: An analysis of samples representing different gonadal hormone states

Western blot is routinely used to quantify differences in the levels of target proteins in tissues. Standard methods typically use measurements of housekeeping proteins to control for variations in loading and protein transfer. This is problematic, however, when housekeeping proteins also are affected by experimental conditions such as injury, disease, and/or gonadal hormone manipulations. Our goal was to evaluate an alternative and perhaps superior method for conducting Western blot analysis of brain tissue homogenates from rats with distinct physiologically relevant gonadal hormone states. Tissues were collected from the hippocampus, frontal cortex, and striatum of young adult female rats that either were ovariectomized to model surgical menopause, or were treated with the ovatotoxin 4-vinylcyclohexene diepoxide (VCD) to model transitional menopause. Tissues also were collected from rats with a normal estrous cycle killed at proestrus when estradiol levels are high, and at diestrus when estradiol levels are low. Western blot detection of α-tubulin, β-actin, and GAPDH was performed and were compared for sensitivity and reliability with a fluorescent total protein stain (REVERT^®). Results show that the total protein stain was much less variable across samples and had a greater linear range than α-tubulin, β-actin, or GAPDH. The stain was stable and easy to use, and did not interfere with the immunodetection or multiplexed detection of the housekeeping proteins. In addition, we show that normalization of our data to total protein, but not to GAPDH, revealed significant differences in α-tubulin expression in the hippocampus as a function of treatment, and that gel-to-gel consistency in measuring differences between paired samples run on multiple gels was significantly better when data were normalized to total protein than when normalized to GAPDH. These results demonstrate that the REVERT^® total protein stain can be used in Western blot analysis of brain tissue homogenates to control for variations in loading and protein transfer, and provides significant advantages over the use of housekeeping proteins for quantifying changes in the levels of multiple target proteins.

Ulipristal Acetate Interferes With Actin Remodeling Induced by 17β-Estradiol and Progesterone in Human Endometrial Stromal Cells

Ulipristal acetate (UPA) is a selective progesterone receptor modulator (SPRM) used for emergency contraception and for the medical management of symptomatic uterine fibroids (UF). Treatment with UPA turns in amenorrhea and UF volume reduction. Treatment with UPA is associated with the frequent development of benign, transitory endometrial changes known as SPRM-associated endometrial changes (PAECs). Why PAECs develop and their biological or cellular basis is unknown. Sex steroids, including estrogen and progesterone, are established modulators of the actin cytoskeleton in various cells, including endometrial cells. This explains several morphological and functional changes in endometrial cells. We thus hypothesized that UPA may alter the appearance of the endometrium by interfering with the actions of 17β-estradiol (E2) or progesterone (P4) on actin dynamics. We isolated and cultured human endometrial stromal cells (ESC) from endometrial biopsies from healthy fertile women. Treatment with E2 or P4 stimulated visible actin rearrangements with actin remodeling toward the membrane. Activation through phosphorylation of the actin regulatory proteins, Moesin, and focal adhesion kinase (FAK), hacked actin remodeling induced by E2 and P4. Membrane re-localization of Paxillin and Vinculin were also induced by E2 and P4, showing the formation of focal adhesion complexes. All these E2 and P4 actions were inhibited by co-treatment with UPA, which was otherwise inactive if given alone. The cytoskeletal changes induced by E2 and P4 turned into increased motility of ESC, and UPA again blocked the actions E2 and P4. In conclusion, we find that UPA interferes with the cytoskeletal actions of E2 and P4 in ESC. This finding helps understanding the mode of actions of SPRMs in the endometrium and may be relevant for other potential clinical applications of UPA.

Literature-based condition-specific miRNA-mRNA target prediction

miRNAs are small non-coding RNAs that regulate gene expression by binding to the 3'-UTR of genes. Many recent studies have reported that miRNAs play important biological roles by regulating specific mRNAs or genes. Many sequence-based target prediction algorithms have been developed to predict miRNA targets. However, these methods are not designed for condition-specific target predictions and produce many false positives; thus, expression-based target prediction algorithms have been developed for condition-specific target predictions. A typical strategy to utilize expression data is to leverage the negative control roles of miRNAs on genes. To control false positives, a stringent cutoff value is typically set, but in this case, these methods tend to reject many true target relationships, i.e., false negatives. To overcome these limitations, additional information should be utilized. The literature is probably the best resource that we can utilize. Recent literature mining systems compile millions of articles with experiments designed for specific biological questions, and the systems provide a function to search for specific information. To utilize the literature information, we used a literature mining system, BEST, that automatically extracts information from the literature in PubMed and that allows the user to perform searches of the literature with any English words. By integrating omics data analysis methods and BEST, we developed Context-MMIA, a miRNA-mRNA target prediction method that combines expression data analysis results and the literature information extracted based on the user-specified context. In the pathway enrichment analysis using genes included in the top 200 miRNA-targets, Context-MMIA outperformed the four existing target prediction methods that we tested. In another test on whether prediction methods can re-produce experimentally validated target relationships, Context-MMIA outperformed the four existing target prediction methods. In summary, Context-MMIA allows the user to specify a context of the experimental data to predict miRNA targets, and we believe that Context-MMIA is very useful for predicting condition-specific miRNA targets.

LH and FSH promote migration and invasion properties of a breast cancer cell line through regulatory actions on the actin cytoskeleton

Reproductive hormones influence breast cancer development and progression. While the actions of sex steroids in this setting are established, tentative evidence suggests that follicle-stimulating hormone (FSH) and luteinizing hormone (LH) may also play a role, yet this remains elusive. We here identify that T-47D breast cancer cells express functional receptors for FSH and LH, and that these hormones regulate breast cancer cell motility and invasion through the control of the actin cytoskeleton and the formation of cortical actin aggregates and focal adhesion complexes. Such actions are mediated by the cytoskeletal controllers Moesin and focal adhesion kinase (FAK). Moesin is recruited rapidly by FSH and LH through a signaling cascade requiring the G protein Gα₁₃ and the Rho-associated kinase, ROCK-2. FSH and LH activate FAK via a Gα_i/β and c-Src-dependent signaling cascade. Both cascades involve signaling to phosphatidylinositol-3 kinase and Akt. FSH and LH receptors and the related signaling intermediates are necessary for the actions of gonadotrophins on breast cancer cell cytoskeletal rearrangement, migration and invasion. These findings provide original information on the actions of gonadotrophins on breast cancer cells and may have clinical implications for the use of drugs that modulate gonadotrophins in breast cancer patients.

Effects of ospemifene on the female reproductive and urinary tracts: translation from preclinical models into clinical evidence

Objective

Treatment of menopausal symptoms by compounds with tissue-selective estrogen agonist/antagonist effects, often called selective estrogen receptor modulators, has been researched as an alternative to the use of estrogen therapy. These structurally diverse molecules elicit tissue-dependent responses in hormone-responsive tissues and organs, exhibiting variations in estrogenic activity in preclinical models of postmenopausal reproductive tissues that may improve postmenopausal women’s health (eg, prevention and treatment of breast cancer, osteoporosis, and vulvar and vaginal atrophy).

Methods

This literature review investigates whether preclinical data predicted the clinical effects of ospemifene on female reproductive and urinary tract tissues and compares these findings with the specific vaginal effects of other estrogen receptor agonists/antagonists (tamoxifen, raloxifene, and bazedoxifene) in preclinical and clinical studies. Lasofoxifene, although not currently available, is included because of its unique effects on vaginal tissue.

Results

The response of endometrial and vaginal tissues to estrogen receptor agonists/antagonists can be differentiated using transvaginal ultrasound, endometrial histopathology, cytologic examination of vaginal smears, assessment of physical changes in the vagina, and relief of symptoms associated with vulvar and vaginal atrophy (such as dyspareunia).

Conclusions

Available evidence indicates that ospemifene has unique effects on tissue, leading to a favorable long-term profile for the relief of vulvar and vaginal atrophy compared with other estrogen receptor agonists/antagonists (eg, tamoxifen, raloxifene, and bazedoxifene) with no short-term concerns about endometrial safety (based on endometrial hyperplasia, carcinoma, endometrial spotting, and endometrial bleeding).

Estrogen-dependent expression and subcellular localization of the tight junction protein claudin-4 in HEC-1A endometrial cancer cells

Endometrial cancer is the most common female reproductive cancer in the United States and is associated with deregulated tight junction protein expression. Given the highly estrogen-responsive nature of this tissue, we investigated the effects of estrogen and its agonist, 4-OH TAM, on the expression and subcellular localization of the tight junction protein claudin-4 (CLDN-4), in HEC-1A endometrial cancer cells. In untreated HEC-1A cells, we observed dramatic overexpression of claudin-4 protein. In addition, differential detergent extraction analysis indicated that claudin-4 was localized primarily in the membrane but also found in the cytosolic, nuclear and cytoskeletal fractions. Upon exposure of HEC-1A to estradiol (E2), we observed a biphasic effect both on the overall expression of claudin-4 protein and on its cytosolic and cytoskeletal presence as demonstrated by immunoblot analysis. Immunofluorescence analysis also revealed a biphasic effect of E2 on claudin-4 expression. In contrast, we observed no changes in expression levels nor in the subcellular distribution patterns of claudin-4 in HEC-1A cells treated with different concentrations of 4-OH TAM. The intracellular presence of CLDN-4 coupled with the biphasic effects of E2 on CLDN-4 expression in the cytoskeleton suggest that this protein may be involved in cell signaling to and from TJs.

Proteomic analysis of porcine endometrial tissue during peri-implantation period reveals altered protein abundance

In mammals, successful pregnancy depends upon the readiness of uterus for implantation, followed by correct communication between the endometrium and the developing conceptus. The objective of this study was to elucidate changes in protein abundance associated with progression of estrous cycle and pregnancy from Day 9 to Day 12. We analyzed porcine endometrial tissue lysates by 2D-DIGE. Abundance of several proteins was altered depending upon the pregnancy status of animals. MALDI-TOF/TOF was used to identify a number of these proteins. Endometrial proteins that increased from Day 9 to Day 12 of cycle included annexin A4, beta-actin, apolipoprotein, ceruloplasmin and afamin. Changes in protein abundances associated with conceptus secreted factors, including haptoglobin, prolyl-4-hydroxylase, aldose-reductase and transthyretin, were also observed. Functional analysis revealed that endometrial proteins with altered abundance on Day 12 irrespective of the reproductive status were related to growth and remodeling, acute phase response and free radical scavenging, whereas transport and small molecule biochemistry were the functions activated in the pregnant endometrium as compared to the cyclic endometrium. These data provide information on dynamic physiological processes associated with uterine endometrial function of the cyclic and pregnant endometrium during period of maternal recognition of pregnancy in pigs and may potentially demonstrate a protein profile associated with successful pregnancy.

BIOLOGICAL SIGNIFICANCE

In pigs, the fertility rates are generally very high but the early embryonic loss that occurs during the second and third weeks of gestation critically affects the potential litter size. Temporal changes that take place in the uterine environment during the period of early pregnancy in pigs and a cross-talk between the uterus and the embryo play an important role in embryonic survival and successful pregnancy. A better understanding of the molecular changes associated with these processes will pave way for understanding of endometrial functions and help towards increasing embryo survival. In this study, we present a 2D-DIGE based analysis of changes in porcine endometrial proteome that are associated with progression of cycle and progression of pregnancy. The network analysis of the results clearly revealed the pathways that are involved in rendering the endometrium receptive to the presence of embryo and also the changes that are result of molecular communication between the endometrium and the conceptuses. This comprehensive identification of proteomic changes in the porcine endometrium could be a foundation for targeted studies of proteins and pathways potentially involved in abnormal endometrial receptivity, placentation and embryo loss.

Estrogens induce rapid cytoskeleton re-organization in human dermal fibroblasts via the non-classical receptor GPR30

The post-menopausal decrease in estrogen circulating levels results in rapid skin deterioration pointing out to a protective effect exerted by these hormones. The identity of the skin cell type responding to estrogens is unclear as are the cellular and molecular processes they elicit. Here, we reported that lack of estrogens induces rapid re-organization of the human dermal fibroblast cytoskeleton resulting in striking cell shape change. This morphological change was accompanied by a spatial re-organization of focal adhesion and a substantial reduction of their number as evidenced by vinculin and actin co-staining. Cell morphology and cytoskeleton organization was fully restored upon 17β-estradiol (E2) addition. Treatment with specific ER antagonists and cycloheximide respectively showed that the E2 acts independently of the classical Estrogen Receptors and that cell shape change is mediated by non-genomic mechanisms. E2 treatment resulted in a rapid and transient activation of ERK1/2 but not Src or PI3K. We show that human fibroblasts express the non-classical E2 receptor GPR30 and that its agonist G-1 phenocopies the effect of E2. Inhibiting GPR30 through treatment with the G-15 antagonist or specific shRNA impaired E2 effects. Altogether, our data reveal a novel mechanism by which estrogens act on skin fibroblast by regulating cell shape through the non-classical G protein-coupled receptor GPR30 and ERK1/2 activation.

Sex Hormones Regulate Cytoskeletal Proteins Involved in Brain Plasticity

In the brain of female mammals, including humans, a number of physiological and behavioral changes occur as a result of sex hormone exposure. Estradiol and progesterone regulate several brain functions, including learning and memory. Sex hormones contribute to shape the central nervous system by modulating the formation and turnover of the interconnections between neurons as well as controlling the function of glial cells. The dynamics of neuron and glial cells morphology depends on the cytoskeleton and its associated proteins. Cytoskeletal proteins are necessary to form neuronal dendrites and dendritic spines, as well as to regulate the diverse functions in astrocytes. The expression pattern of proteins, such as actin, microtubule-associated protein 2, Tau, and glial fibrillary acidic protein, changes in a tissue-specific manner in the brain, particularly when variations in sex hormone levels occur during the estrous or menstrual cycles or pregnancy. Here, we review the changes in structure and organization of neurons and glial cells that require the participation of cytoskeletal proteins whose expression and activity are regulated by estradiol and progesterone.

Update on raloxifene: mechanism of action, clinical efficacy, adverse effects, and contraindications

Raloxifene is the only selective estrogen receptor modulator approved for long-term treatment in the prevention of osteoporotic fractures and for the reduction of invasive breast cancer risk in post-menopausal women. The demonstrated beneficial effects on bone and mammalian tissue led clinical and molecular research to focus mainly on these organs, giving less attention to all other systemic effects. The aim of this review was to evaluate all described systemic effects of raloxifene, investigating its molecular and tissutal mechanism of action. A literature research was carried out in electronic databases MEDLINE, EMBASE, ScienceDirect, and the Cochrane Library in interval time between 2000 and 2012. Outcomes were considered in relation to positive/adverse effects concerning bone metabolism, lipid metabolism, coagulation pattern, menopausal symptoms, breast cancer onset, and endometrial cancer onset. Raloxifene acts as an estrogen agonist or antagonist depending on the tissue. This feature is related to specific actions on at least 2 distinct estrogen receptors, whose proportions vary according to tissue type. Raloxifene is a drug for the treatment of osteoporosis and for the prevention of estrogen receptor-positive breast cancer because it guarantees a safety profile on the endometrium. Raloxifene is furthermore an effective therapy in women with increased levels of plasma cholesterol. Raloxifene treatment shifts the coagulation pattern toward prothrombosis, and the patients should be exhaustively informed about the risks associated with therapy. Raloxifene does not show to affect memory and cognition. Finally, it is noteworthy that quality-of-life studies demonstrated some favorable effects of raloxifene.

Effects of progesterone and medroxyprogesterone on actin remodeling and neuronal spine formation

Sex steroids are important regulators of neuronal cell morphology, and this is critical for gender differences in brain function and dysfunction. Neuronal morphology is controlled by multiprotein complexes including moesin (a member of the ezrin/radixin/moesin family), focal adhesion kinase (FAK), or the Wiskott-Aldrich syndrome protein-family verprolin homologous (WAVE1) protein, controlling dynamic remodeling of the cytoskeleton and cell membrane. We investigated the actions of natural progesterone (P) and of the synthetic progestin medroxyprogesterone acetate (MPA) on actin remodeling, focal adhesion complex formation, and actin branching in rat cortical neurons. Treatment with P and, to a lesser extent, MPA, increases the number and density of dendritic spines. P increases the phosphorylation of moesin, FAK, and WAVE1, and their redistribution toward cell membrane sites where spines are formed. Signaling to moesin is achieved by PR via a Gα/Gβ-dependent signaling to the small GTPase Ras homolog gene family, member A and its related kinase, Rho-associated kinase-2. In parallel, WAVE1 recruitment is triggered by a Gαi/Gβ-dependent signaling of PR to c-Src, FAK, and Rac1 GTPase. Rac1 recruits cyclin-dependent kinase-5, which phosphorylates WAVE1. Silencing of moesin, FAK, or WAVE1 abrogates the increase in dendritic spines induced by progesterone. In all applications, MPA is found to act similar to P, albeit with a lower efficacy. In conclusion, our findings indicate that the control of actin polymerization and branching and focal adhesion complex formation via moesin, FAK, and WAVE1 is a key function of progesterone receptor in neurons, which may be relevant for the regulation of dendritic spine turnover and neuronal plasticity.

17β-Estradiol and 17α-estradiol induce rapid changes in cytoskeletal organization in cultured oligodendrocytes

Dramatic changes in the cytoskeleton and the morphology of oligodendrocytes (OLs) occur during various stages of the myelination process. OLs in culture produce large membrane sheets containing cytoskeletal veins of microtubules and actin filaments. We recently showed that estrogen receptors (ER) related to ERα/β were expressed in the membrane sheets of mature OLs in culture. Ligation of these or other membrane ERs in OLs with both 17β- and 17α-estradiol mediated rapid non-genomic signaling. Here, we show that estrogens also mediate rapid non-genomic remodeling of the cytoskeleton in mature OLs in culture. 17β-Estradiol caused a rapid loss of microtubules and the actin cytoskeleton in the OL membrane sheets. It also increased phosphorylation of the actin filament-severing protein cofilin, thus inactivating it. Staining for actin barbed ends with rhodamine-actin showed that it decreased the amount of actin barbed ends. 17α-Estradiol, on the other hand, increased the percentage of cells with abundant staining of actin filaments and actin barbed ends, suggesting that it stabilized and/or increased the dynamics of the actin cytoskeleton. The specific ERα and ERβ agonists, 4,4',4″-(4-propyl-(1H)-pyrazole-1,3,5-triyl) trisphenol (PPT) and diarylpropionitrile 2,3-bis(4-hydroxy-phenyl)-propionitrile (DPN), respectively, also caused the rapid phosphorylation of cofilin. Estrogen-induced phosphorylation of cofilin was inhibited by Y-27632, a specific inhibitor of the Rho-associated protein serine/threonine kinase (ROCK). The Rho/ROCK/cofilin pathway is therefore implicated in actin rearrangement via estrogen ligation of membrane ERs, which may include forms of ERα and ERβ. These results indicate a role for estrogens in modulation of the cytoskeleton in mature OLs, and thus in various processes required for myelinogenesis.

Raf-1 levels determine the migration rate of primary endometrial stromal cells of patients with endometriosis

Endometriosis is a disease characterized by the localization of endometrial tissue outside the uterine cavity. The differences observed in migration of human endometrial stromal cells (hESC) obtained from patients with endometriosis versus healthy controls were proposed to correlate with the abnormal activation of Raf-1/ROCKII signalling pathway. To evaluate the mechanism by which Raf-1 regulates cytoskeleton reorganization and motility, we used primary eutopic (Eu-, n = 16) and ectopic (Ec-, n = 8; isolated from ovarian cysts) hESC of patients with endometriosis and endometriosis-free controls (Co-hESC, n = 14). Raf-1 siRNA knockdown in Co- and Eu-hESC resulted in contraction and decreased migration versus siRNA controls. This phenotype was reversed following the re-expression of Raf-1 in these cells. Lowest Raf-1 levels in Ec-hESC were associated with hyperactivated ROCKII and ezrin/radixin/moesin (E/R/M), impaired migration and a contracted phenotype similar to Raf-1 knockdown in Co- and Eu-hESC. We further show that the mechanism by which Raf-1 mediates migration in hESC includes direct myosin light chain phosphatase (MYPT1) phosphorylation and regulation of the levels of E/R/M, paxillin, MYPT1 and myosin light chain (MLC) phosphorylation indirectly via the hyperactivation of ROCKII kinase. Furthermore, we suggest that in contrast to Co-and Eu-hESC, where the cellular Raf-1 levels regulate the rate of migration, the low cellular Raf-1 content in Ec-hESC, might ensure their restricted migration by preserving the contracted cellular phenotype. In conclusion, our findings suggest that cellular levels of Raf-1 adjust the threshold of hESC migration in endometriosis.

RNAi-mediated blocking of ezrin reduces migration of ectopic endometrial cells in endometriosis

Ezrin is a member of the ezrin-radixin-moesin (ERM) family of membrane-cytoskeletal linkage proteins. It is important for maintenance of cell shape, adhesion, migration and division. The overexpression of ezrin in some tumours is associated with increased cell migration that is mediated by the Rho/ROCK family of small GTPases. To investigate the role of ezrin in the migration of ectopic endometrial cells in endometriosis, we conducted real-time quantitative RT-PCR analysis of the eutopic and ectopic endometrium from women with endometriosis compared with those without the disease. RNAi, wound healing assays and western blot analysis of endometriotic cells were also included in this research. We found significantly higher levels of mRNA expression of ezrin (0.42 versus 0.27, P < 0.05), RhoA (0.99 versus 0.74, P < 0.05), RhoC (0.79 versus 0.43, P < 0.005) and ROCK1 (0.68 versus 0.38, P < 0.005) in the ectopic endometrial cells compared with the eutopic endometrial cells in endometriosis. Blocking ezrin with small-interfering RNA reduced the migration of ectopic endometrial cells with decreased expression of RhoA (42.68%), RhoC (58.42%) and ROCK1 (59.88%). Our results indicate that the over-expression of ezrin in endometriosis may play a significant role in the migration of endometrial cells of endometriosis, and the RhoC/Rock pathway may provide a promising treatment target.

Expression and activation of the membrane-cytoskeleton protein ezrin during the normal endometrial cycle

OBJECTIVE

To examine total ezrin expression (ezrin and phospho-ezrin) through the normal endometrial cycle and to correlate ezrin activation and localization with cytologic changes.

DESIGN

Experimental laboratory study.

SETTING

University medical centers.

PATIENT(S)

Reproductive-age women.

INTERVENTION(S)

A total of 36 samples of normal early, mid-, and late proliferative- and secretory-phase endometrium were studied for immunoreactive total ezrin (ir-T-ezrin) and phospho-ezrin (ir-p-ezrin) expression by histology, immunohistochemistry, and Western blotting.

MAIN OUTCOME MEASURE(S)

Total ezrin and phospho-ezrin expressions through the normal endometrial cycle.

RESULT(S)

Throughout the cycle ir-T-ezrin is present in the epithelium. The intensity and localization of both ir-ezrin and ir-p-ezrin vary greatly throughout the cycle. The main findings include the following: lateral localization of ir-ezrin/ir-p-ezrin in association with membrane specializations; dense staining around secretory vacuoles (secretory phase); dense staining of the apical surfaces, including microvilli and pinopodes of epithelial cells, especially during the mid- to late secretory phases; and the presence of ezrin in the glandular secretions. Immunoreactive total ezrin and ir-p-ezrin were not expressed by stromal fibroblasts.

CONCLUSION(S)

Ezrin is a prominent protein in the cycling endometrium. The most striking findings were the gravitation of ir-ezrin/ir-p-ezrin to the periphery of secretory vacuoles, localization on apical surfaces of the luminal epithelium, dense ezrin staining in secretory-phase epithelial cell plumes, and the presence of ir-ezrin/ir-p-ezrin in secretory-phase luminal secretions. These findings may have functional implications, especially for implantation biology.

Actin cytoskeleton remodelling by sex steroids in neurones

Cell morphology and its interaction with the extracellular environment are integrated processes involving a number of intracellular controllers orchestrating cytoskeletal proteins and their interaction with the cell membrane and anchorage proteins. Sex steroids are effective regulators of cell morphology and tissue organisation, and recent evidence indicates that this is obtained through the regulation of the actin cytoskeleton. Intriguingly, many of these regulatory actions related to cell morphology are achieved through the rapid, nonclassical signalling of sex steroid receptors to kinase cascades, independently from nuclear alteration of gene expression or protein synthesis. The identification of the mechanistic basis for these rapid actions on cell cytoskeleton has special relevance for the characterisation of the effects of sex steroids under physiological conditions, such as for the development of neurone/neurone interconnections and dendritic spine density. This is considered to be critical for gender-specific differences in brain function and dysfunction. Recent advancements in the characterisation of the molecular basis of the extranuclear signalling of sex steroids help to clarify the role of oestrogen and progesterone in the brain, and may turn out to be of relevance for clinical purposes. This review highlights the regulatory effects of oestrogens and progesterone on actin cytoskeleton and neurone morphology, as well as recent progresses in the characterisation of these mechanisms, providing insights and working hypotheses on possible clinical applications for the modulation of these pathways in the central nervous system.

Comparative Study of Tamoxifen and Raloxifene on Endometrial Cell Proliferation of Female Rats in Persistent Estrus

Objective

The objective of the study was to compare the effect of tamoxifen and raloxifene on the endometrium of female rats in persistent estrus, by Ki-67 protein expression.

Methods

The study comprised 60 Wistar-Hannover female rats in persistent estrus, induced by a single subcutaneous dose of 1.25 mg of testosterone propionate on the second day of age. At 90 days of life, the animals were randomly divided into 3 groups of 20 animals each. Group 1 (control), received only placebo; group 2, the animals were treated with tamoxifen, 250 μg/d; and group 3, the rats were treated with 750 μg/d of raloxifene by gavage during 30 days. Then, the animals were killed, and the endometrium was removed for immunohistochemical analysis of Ki-67 antigen expression. Statistical analysis was performed by β regression model (P < 0.05).

Results

Mean percentages of Ki-67 protein expression in the endometrium of rats in persistent estrus were 43.21% ± 3.39%, 7.36% ± 0.95%, and 7.20% ± 0.76% in groups 1, 2 and 3, respectively (P < 0.001). There was no statistical difference between groups 2 and 3 (P = 0.7159).

Conclusions

The present results indicate that, at the doses and during the time of treatment used, both tamoxifen and raloxifene induce atrophy in a similar way of endometrial epithelium of rats in persistent estrus.

Proteomic analysis of pregnancy-related proteins from pig uterus endometrium during pregnancy

Many important molecular events associated with implantation and development occur within the female reproductive tract, especially within the uterus endometrium, during pregnancy periods. The endometrium includes the mucosal lining of the uterus, which provides a suitable site for implantation and development of a fertilized egg and fetus. To date, the molecular cascades in the uterus endometrium during pregnancy periods in pigs have not been elucidated fully. In this study, we compared the functional regulated proteins in the endometrium during pregnancy periods with those in non-pregnant conditions and investigated changes in expression patterns during pregnancy (days 40, 70, and 93) using two-dimensional gel electrophoresis (2-DE) and western blotting. The functional regulated proteins were identified and discovered from differentially expressed proteins in the uterus endometrium during pregnancy. We discovered 820 protein spots in a proteomic analysis of uterus endometrium tissues with 2-DE gels. We identified 63 of the 98 proteins regulated differentially among non-pregnant and pregnant tissues (matched and unmatched spots). Interestingly, 10 of these 63 proteins are development-, cytoskeleton- and chaperon-related proteins such as transferrin, protein DJ-1, transgelin, galectin-1, septin 2, stathmin 1, cofilin 1, fascin 1, heat shock protein (HSP) 90β and HSP 27. The specific expression patterns of these proteins in the endometrium during pregnancy were confirmed by western blotting. Our results suggest that the expressions of these genes involved in endometrium function and endometrium development from early to late gestation are associated with the regulation of endometrium development for maintaining pregnancy.

2D-DIGE analysis of phospho-enriched fractions from dasatinib-treated melanoma cell lines

Current therapeutic regimes for metastatic melanoma have failed to provide robust clinical responses. Dasatinib has shown anti-proliferative and anti-invasive effects in vitro; however, not all melanoma cells tested were sensitive to dasatinib. We used 2D-DIGE analysis of phospho-enriched fractions to identify phosphoproteins involved in regulating response to dasatinib in an isogenic pair of melanoma cell lines, one sensitive to dasatinib (WM-115) and the other resistant (WM-266-4). In WM-115 cells treated with dasatinib, 18 unique protein species with altered phosphorylation levels were detected. Dasatinib treatment of WM-266-4 cells resulted in phosphoprotein alterations to four unique protein species. Four phosphorylated forms of Annexin-A2 (ANXA2) were increased in WM-115 cells treated with dasatinib, whilst dasatinib treatment did not alter ANXA2 phosphoprotein levels in WM-266-4 cells. Immunoblotting confirmed that phosphorylation of ANXA2, on tyrosine residues, was increased in WM-115 cells treated with dasatinib. Subsequent knockdown of ANXA2 by siRNA significantly inhibited proliferation of WM-115 cells but did not significantly reduce proliferation of WM-266-4 cells. Therefore, ANXA2 plays a role in regulating proliferation in dasatinib-sensitive WM-115 cells and could potentially play a role in sensitivity to dasatinib in melanoma cells.

Estrogen receptor-{alpha} promotes endothelial cell motility through focal adhesion kinase

Sex steroids play a key role in cell movement and tissue organization. Cell migration requires the integration of events that induce changes in cell structure such as protrusion, polarization and traction toward the direction of migration. These actions are driven by actin remodeling and are stabilized by the development of adhesion sites to extracellular matrix via transmembrane receptors linked to the actin cytoskeleton. Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that facilitates cell migration via the control of the turnover of focal adhesion complexes. In this work, we demonstrated that 17β-estradiol (E(2)) regulates actin remodeling and cell movement in human umbilical vein endothelial cells through the recruitment of FAK. E(2) induces phosphorylation of FAK and its translocation toward membrane sites where focal adhesion complexes are assembled. This process is triggered via a Gα/Gβ protein-dependent, rapid extra-nuclear signaling of estrogen receptor-α (ERα) that interacts in a multiprotein complex with c-Src, phosphatidylinositol 3-OH kinase and FAK. Phosphorylation of FAK is fundamental for its activation, translocation to the plasmatic membrane and the subsequent formation of focal adhesion complexes. In conclusion, we found that ERα enhances endothelial cell motility through the dynamic control of actin arrangement and the formation of focal adhesion complexes. The identification of these processes broadens the understanding of the actions of estrogens on endothelial cells and could be relevant in physiological or pathological settings.

Estrogen receptor-alpha promotes breast cancer cell motility and invasion via focal adhesion kinase and N-WASP

The ability of cancer cells to move and invade the surrounding environment is the basis of local and distant metastasis. Cancer cell movement requires dynamic remodeling of the cytoskeleton and cell membrane and is controlled by multiprotein complexes including focal adhesion kinase (FAK) or the Neural Wiskott-Aldrich Syndrome Protein (N-WASP). We show that 17β-estradiol induces phosphorylation of FAK and its translocation toward membrane sites where focal adhesion complexes are assembled. This process is triggered via a Gα/Gβ protein-dependent, rapid extranuclear signaling of estrogen receptor α interacts in a multiprotein complex with c-Src, phosphatidylinositol 3-OH kinase, and FAK. Within this complex FAK autophosphorylation ensues, and activated FAK recruits the small GTPase cdc42, which, in turn, triggers N-WASP phosphorylation. This results in the translocation of Arp2/3 complexes at sites where membrane structures related to cell movement are formed. Recruitment of FAK and N-WASP is necessary for cell migration and invasion induced by 17β-estradiol in breast cancer cells. Our findings identify an original mechanism through which estrogen promotes breast cancer cell motility and invasion. This information helps to understand the effects of estrogen on breast cancer metastasis and may provide new targets for therapeutic interventions.

Estrogen regulates endometrial cell cytoskeletal remodeling and motility via focal adhesion kinase

OBJECTIVE

To explore the effects of 17β-estradiol (E(2)) on cytoskeletal remodeling and motility of endometrial stromal cells (ESC) and Ishikawa cells and to characterize the role of focal adhesion kinase (FAK) in these processes.

DESIGN

In vitro study of cytoskeletal remodeling and cellular morphology and motility in ESC or Ishikawa cells.

SETTING

University research center.

PATIENT(S)

Endometrial samples obtained from women requiring endometrial biopsies.

INTERVENTION(S)

Treatments with E(2) and multiple inhibitors of signaling pathways.

MAIN OUTCOME MEASURE(S)

Activation of FAK, actin remodeling, membrane morphology, cell motility, and invasion.

RESULT(S)

Estrogen induces a rapid and concentration-related FAK phosphorylation in ESC and Ishikawa cells. In this time frame, FAK localizes to the plasma membrane at sites of focal adhesion complexes formation, as shown by immunofluorescence. Phosphorylation of FAK in the presence of estrogen depends on the recruitment of both estrogen receptor α and estrogen receptor β and of a rapid G protein-dependent signaling to c-Src and phosphatidylinositol 3-OH kinase. Activation of FAK in ESC and Ishikawa cells is required for estrogen-induced horizontal migration and invasion of three-dimensional matrices of endometrial cells.

CONCLUSION(S)

Estrogen enhances cytoskeletal and membrane remodeling in ESC and Ishikawa cells by controlling FAK, thus resulting in enhanced cell motility and invasion. These findings may have clinical relevance for the development of new therapeutic strategies for the prevention or control of endometrial diseases.

Extra-nuclear signaling of ERalpha to the actin cytoskeleton in the central nervous system

Cell morphology is controlled by a complex and redundant array of intracellular signaling pathways devoted to the regulation of the actin cytoskeleton and of its relationship with the cell membrane and the extracellular matrix. Sex steroids are effective regulators of cell morphology and tissue organization, and recent evidence indicates that this is obtained through the regulation of the cytoskeleton. Intriguingly, many of these regulatory actions related to cell morphology are achieved through rapid, non-classical signaling of sex steroid receptors to kinase cascades, independently from nuclear alteration of gene expression or protein synthesis. The identification of the mechanistic basis for these rapid actions on cell cytoskeleton has special relevance for the characterization of the effects of sex steroids in physiological conditions, such as their role in the control of brain cell remodeling. Brain cell morphology is controlled by estrogens that regulate the development of neuron/neuron interconnections and dendritic spine density. This is thought to be critical for gender-specific differences in brain function and dysfunction. The recent advancements in the characterization of the molecular basis of the extra-nuclear signaling of estrogen helps to understand the role of estrogen in the brain, and may in the future turn out to be of relevance for clinical purposes. This review highlights the regulatory effects on the cytoskeleton and cell morphology of estrogens as well as the recent advances in the characterization of these mechanisms, providing insights and working hypotheses on possible clinical applications for the modulation of these pathways in the central nervous system.

Gene expression profiling studies of three SERMs and their conjugated estrogen combinations in human breast cancer cells: insights into the unique antagonistic effects of bazedoxifene on conjugated estrogens

Bazedoxifene (BZA), a new selective estrogen receptor modulator (SERM) was recently approved in Europe for the prevention and treatment of postmenopausal osteoporosis. Combination therapy using BZA and conjugated estrogens (CE) is currently in late stage development representing a new paradigm for the treatment of menopausal symptoms and prevention of osteoporosis. A GeneChip microarray study was designed to compare gene expression profiles of BZA to that of other SERMs, raloxifene (RAL) and lasofoxifene (LAS). In addition, we compared the gene expression profiles of the three SERMs in combination with CE, a mixture of 10 most abundant estrogens present in Premarin. According to the hierarchical clustering heat map analysis, gene clusters that specifically responded to CE treatments or SERM treatments were identified and gene lists sorted based on a set of cutoff filters. A group of genes differentially regulated by CE were also identified to be antagonized by BZA when comparing CE with the BZA+CE treatment. All three SERMs showed significant antagonistic effect against CE-stimulated cell proliferation, based on the MCF-7 cell proliferation assay and GeneChip data, with the order of antagonist activity being BZA>RAL>LAS. These results indicate that SERMs in combination with CE exhibit differential pharmacology, and therefore, combinations of other SERMs and estrogen preparations may not yield the same effects that are observed in clinic by pairing BZA with CE.