ERbeta Expression Research Articles

Changes in the subcellular and tissue location of estrogen and progesterone receptors in rat uterus after long-term treatment with analogs of gonadoliberin.

Certain therapies with the use of analogs of gonadotropin-releasing hormone (GnRH, gonadoliberin) aim at achieving the effect of desensitization of the pituitary gland that causes inhibition of the hypothalamic-pituitary-gonadal axis. The resulting hormonal changes may influence the location and expression of estrogen and progesterone receptors, as well as their endogenous functions. The aim of the study was to investigate whether long-term administration of low doses of dalarelin (GnRH agonist) and cetrorelix (GnRH antagonist) affected subcellular and tissue-specific location of ERalpha and ERbeta estrogen receptors and progesterone receptor (PR) in rat uterus, as well as explore the extent to which the changes were reversible. Analogs were administered to SPD adult females in the course of 3 months, at a dose of 6 microg/kg b.w. Afterwards, the ovaries and the uterus were resected--in the course of 4 weeks after treatment completion. Tissue paraffin-embedded samples were stained with hematoxyline-eosin for morphological studies or incubated with specific antibodies for the immunohistochemical studies (ABC method). GnRH analogs induced desensitization, resulting in specific and relatively persistent histological changes in the ovaries and the uterus. Strong nuclear reaction for ERalpha in the lining and the glandular epithelial cells in dalarelin-treated rats, and lack of expression changes in cetrorelix-treated rats, were observed in the uterus. Epithelial ERalpha expressions were accompanied by diminished ERbeta and elevated PR expression, as well as diminished ERalpha and ERbeta expression, and unchanged PR expression in the stromal and muscle cells, in both dalarelin- and cetrorelix-treated rats. The majority of the changes were reversible after treatment discontinuation. Long-term exposure to low doses of GnRH analogs causes morphological changes in the uterine tissues, accompanied by reversible changes of the ERalpha, ERbeta and PR expression, possibly influencing tissue sensitivity. These changes indicate that agonist and antagonist regulate ERalpha expression by means of different mechanisms. A functional interaction between the receptors, depending on ERbeta expression, direct influence of analogs on the local hormonal axes, and dose-dependent effects, cannot be excluded. After discontinuation of the analog treatment, the time needed for stabilization of ER and PR expression is shorter than the period of time required to restore histological structure of the uterus.

Estrogen receptor beta 2 is associated with poor prognosis in estrogen receptor alpha-negative breast carcinoma

Our aim was to examine the prognostic significance of ERbeta1 and ERbeta2 expression in ERalpha-negative breast carcinomas. We evaluated nuclear and cytoplasmic expression of ERbeta1 and ERbeta2 by immunohistochemistry in a group of 95 patients with long follow-up. ERbeta1 and ERbeta2 status was correlated with clinicopathological parameters and disease outcome. Univariate and multivariate analyses of ERbeta1 and ERbeta2 as independent markers of disease-free survival (DFS) were carried out using the Cox proportional hazards model. Nuclear ERbeta1 (nERbeta1) and nERbeta2 status was positively correlated (p=0.01). nERbeta1 positivity was associated with low histological grade (p=0.01) in all patients and in the nERbeta2-positive subgroup (p=0.03) but not in the nERbeta2-negative (p=0.27). nERbeta2 positivity was associated with lymph node involvement and tumor relapse in all cases (p<0.00 and p<0.00, respectively) and in the nERbeta1-negative subgroup (p<0.00 and p<0.00, respectively) but not in the nERbeta1-positive (p=0.09 and p=0.20, respectively). nERbeta2 positivity was associated with poor DFS in all patients (log-rank p<0.00), in the post-menopausal patient subgroup (log-rank p=0.02) and in the HER2-negative (triple-negative) subgroup (log-rank p=0.04). Cox multivariate analysis including ERbeta1, ERbeta2 and established clinicopathological variables highlighted ERbeta2 as an independent marker of early disease recurrence (hazard ratio 4.87; 95% confidence interval 1.07-22.3; p=0.04). High nERbeta2 is an independent marker of early relapse in ERalpha-negative breast carcinoma, and in particular, in the nERbeta1-negative, the post-menopausal patient and the triple-negative subgroups. These findings suggest that inhibition of expression and/or function of ERbeta2 could improve disease outcome.

The prognostic value of estrogen receptor beta and proline-, glutamic acid- and leucine-rich protein 1 (PELP1) expression in ovarian cancer

BackgroundProline-, glutamic acid-, and leucine-rich protein 1 (PELP1), a coregulator of the estrogen receptors (ERs) alpha and beta, is a potential proto-oncogene in hormone dependent gynecological malignancies. To better understand the role of PELP1 in epithelial ovarian cancer (EOC), the protein expression and prognostic significance of PELP1 was evaluated together with ERalpha and ERbeta in EOC tissues.MethodsThe expression of PELP1, ERalpha, and ERbeta was characterized in tumor tissues of 63 EOC patients. The prognostic value was calculated performing log-rank tests and multivariate Cox-Regression analysis. In a second step, validation analysis in an independent set of 86 serous EOC patients was performed.ResultsNuclear PELP1 expression was present in 76.2% of the samples. Prevalence of PELP1 expression in mucinous tumors was significantly lower (37.5%) compared to serous (85.7%) and endometrioid tumors (86.7%). A significant association between PELP1 expression and nuclear ERbeta staining was found (p=0.01). Positive PELP1 expression was associated with better disease-free survival (DFS) (p=0.004) and overall survival (OS) (p=0.04). The combined expression of ERbeta+/PELP1+ revealed an independent association with better DFS (HR 0.3 [0.1-0.7], p=0.004) and OS (HR 0.3 [0.1-0.7], p=0.005). In the validation set, the combined expression of ERbeta+/PELP1+ was not associated with DFS (HR 0.7 [0.4-1.3], p=0.3) and OS (HR 0.7 [0.3-1.4], p=0.3).ConclusionPositive immunohistochemical staining for the ER coregulator PELP1, alone and in combination with ERbeta, might be of prognostic relevance in EOC.

P014 The inflammasome induces macrophage-mediated disruption of the epithelial barrier

and ER-alpha expression, Ki-67 and Tunel were evaluated by immunohystochemical methods. Results: ER-beta, ER-alpha expression and their ratio, assessed in normal mucosa, in UC and in UC-dysplasia, did not show significant changes while in UC-carcinoma revealed a dramatic fall of ER-beta expression (p < 0.01) and still more ER-beta/ERalpha (p < 0.005). Apoptosis and Tunel/Ki-67 ratio demonstrated a statistically significant progressive increase from UC to UCcarcinoma through UC-dysplasia. Conclusions: Our experience assessed modifications of ERs expression, apoptosis and cell proliferation in dysplasiacarcinoma sequence in the course of UC. We observed a dramatic fall of ER-beta, ER-beta/ER-alpha and a progressive increase of apoptosis in progressive steps from long-lasting UC to UC-carcinoma. As observed in adenoma model, the ERbeta drop could be a biomarker of dysplasia progression and a relevant point in the study of carcinogenesis in the course of UC. Further studies are warranted.

P015 The influence of COX-1/COX-2 inhibitors on the Na/Li-countertransport and Na, K, 2Cl-cotransport in erythrocytes of rats with experimental colitis

and ER-alpha expression, Ki-67 and Tunel were evaluated by immunohystochemical methods. Results: ER-beta, ER-alpha expression and their ratio, assessed in normal mucosa, in UC and in UC-dysplasia, did not show significant changes while in UC-carcinoma revealed a dramatic fall of ER-beta expression (p < 0.01) and still more ER-beta/ERalpha (p < 0.005). Apoptosis and Tunel/Ki-67 ratio demonstrated a statistically significant progressive increase from UC to UCcarcinoma through UC-dysplasia. Conclusions: Our experience assessed modifications of ERs expression, apoptosis and cell proliferation in dysplasiacarcinoma sequence in the course of UC. We observed a dramatic fall of ER-beta, ER-beta/ER-alpha and a progressive increase of apoptosis in progressive steps from long-lasting UC to UC-carcinoma. As observed in adenoma model, the ERbeta drop could be a biomarker of dysplasia progression and a relevant point in the study of carcinogenesis in the course of UC. Further studies are warranted.

Estrogen Receptors Alpha and Beta in Male and Female Gerbil Prostates1

The Mongolian gerbil (Meriones unguiculatus, Gerbilinae: Muridae) is useful for prostate studies, because both males and females spontaneously develop prostatic disorders with age. Estrogens regulate prostate homeostasis via two estrogen receptors, ER alpha (ESR1) and ER beta (ESR2), but the cellular distribution and regulation of these receptors in the gerbil prostate has not been described. Both receptors were localized by immunohistochemistry in the ventral prostate of intact male and female gerbils, in males 7 and 21 days after castration, and in females treated with testosterone for 7 and 21 days. In male and female adult gerbils, ER alpha was detected mainly in prostatic stromal cells, whereas ER beta was present mostly in secretory and basal cells. More ER alpha-positive stromal cells were found in females than in males, as was a reduction toward the male value in females treated with testosterone. Castration did not alter ER alpha expression. Testosterone was necessary for maintenance of ER beta in the male prostate epithelium: ER beta expression declined markedly in prostates of males older than 1 yr, and castration of 4-mo-old males caused a reduction in ER beta to levels seen in 1-yr-old males. Because ER beta is an antiproliferative receptor, its loss with age may predispose the aging gerbil to proliferative diseases of the prostate.

ERβ1 represses basal-like breast cancer epithelial to mesenchymal transition by destabilizing EGFR

IntroductionEpithelial to mesenchymal transition (EMT) is associated with the basal-like breast cancer phenotypes. Sixty percent of basal-like cancers have been shown to express wild-type estrogen receptor beta (ERβ1). However, it is still unclear whether the ERβ expression is related to EMT, invasion and metastasis in breast cancer. In the present study, we examined whether ERβ1 through regulating EMT can influence invasion and metastasis in basal-like cancers.MethodsBasal-like breast cancer cells (MDA-MB-231 and Hs578T), in which ERβ1 was either overexpressed or down-regulated were analyzed for their ability to migrate and invade (wound-healing assay, matrigel-coated Transwell assay) as well as for the expression of EMT markers and components of the EGFR pathway (immunoblotting, RT-PCR). Co-immunoprecipitation and ubiquitylation assays were employed to examine whether ERβ1 alters epidermal growth factor receptor (EGFR) protein degradation and the interaction between EGFR and the ubiquitin ligase c-Cbl. The metastatic potential of the ERβ1-expressing MDA-MB-231 cells was evaluated in vivo in a zebrafish xenotransplantation model and the correlation between ERβ1 and E-cadherin expression was examined in 208 clinical breast cancer specimens by immunohistochemistry.ResultsHere we show that ERβ1 inhibits EMT and invasion in basal-like breast cancer cells when they grow either in vitro or in vivo in zebrafish. The inhibition of EMT correlates with an ERβ1-mediated up-regulation of miR-200a/b/429 and the subsequent repression of ZEB1 and SIP1, which results in increased expression of E-cadherin. The positive correlation of ERβ1 and E-cadherin expression was additionally observed in breast tumor samples. Down-regulation of the basal marker EGFR through stabilization of the ubiquitin ligase c-Cbl complexes and subsequent ubiquitylation and degradation of the activated receptor is involved in the ERβ1-mediated repression of EMT and induction of EGFR signaling abolished the ability of ERβ1 to sustain the epithelial phenotype.ConclusionsTaken together, the results of our study strengthen the association of ERβ1 with the regulation of EMT and propose the receptor as a potential crucial marker in predicting metastasis in breast cancer.

The metallohormone cadmium modulates AhR-associated gene expression in the small intestine of rats similar to ethinyl-estradiol

Cadmium (Cd) affects the expression of estrogen receptor (ER) and aryl hydrocarbon receptor (AhR)-associated genes in rat uterus and elicits estrogen-like activity in vitro. The small intestine is highly exposed to dietary Cd which may mimic or antagonize estrogen action in this tissue. We investigated the effects of Cd and 17-alpha-ethinylestradiol (EE₂) on AhR-associated gene expression after oral exposure of ovariectomized female Wistar rats, and metallothionein (Mt1a) expression as a typical metal-response marker. Mt1a in the small intestine was strongly induced by co-treatment with CdCl₂ at 2 mg/kg b.wt (Cd 2) and 0.1 mg/kg b.wt EE2 than by the single compound (3-day gavage). The Cd 2-induced down-regulation of Cyp1a1, Gsta2, and Nqo1 mRNA was not antagonized by pure anti-estrogen (2.5 mg/kg b.wt ZK191703 s.c., ZK). Interestingly, the EE₂-induced down-regulation of Cyp1a1, Gsta2, and Nqo1 mRNA was antagonized by Cd 2 in vivo and in colon cancer cell lines (HT-29 and CaCo-2, treated 5 days with Cd 1 µM and/or E₂ 0.01 µM) with low or no ER-beta expression. Dose dependency was studied after Cd exposure with drinking water (5 and 50 ppm CdCl₂ equivalent to 0.4 and 4 mg/kg b.wt; Cd 0.4, Cd 4) for 28 days and EE₂ as reference. Intestinal Mt1a expression was dose dependently induced, while AhR target genes were down-regulated by Cd 0.4 similar to EE₂ and more pronounced than by Cd 4. We propose that Cd modulates intestinal AhR-associated gene expression similar to estrogens, but (contrary to its effects in uterus) via ER-independent and/or ER-beta-mediated mechanisms. Our new data suggest interference of Cd with estrogen and AhR signaling in the small intestine.

Estrogen in obesity-associated colon cancer: friend or foe? Protecting postmenopausal women but promoting late-stage colon cancer

Obesity is associated with the increased incidence of colon cancer. Many cancer risk factors have been identified including increased blood levels of insulin, leptin, interleukin-6, interleukin-17, tumor necrosis factor-alpha, and decreased blood levels of adiponectin. However, the role of blood levels of estrogen in obesity-associated colon cancer is controversial. Evidence showed that obesity affected men more strongly than women in the carcinogenesis of colon cancer, indicating protective effect of estrogen which is increased in obesity. However, an epidemiological study has also shown that endogenous estradiol level is an independent risk factor for colon cancer, positively associated with colon cancer after normalizing insulin, IGF-1. The controversial opinions may be caused by different effects of ER-alpha and ER-beta. ER-alpha can increase colon cancer cell proliferation and increase cancer incidence. ER-beta has the opposite effect to ER-alpha, and it causes apoptosis of colon cancer cells. The normal colonocytes mainly express ER-beta. Therefore, increased estrogen in obesity may have protective effect via ER-beta in obesity-associated colon cancer. However, with the development of colon cancer, ER-alpha is increased and ER-beta is decreased. In the late stage of colon cancer, estrogen may promote cancer development via ER-alpha. The different effects and expression of ER-alpha and ER-beta may explain the different results observed in several epidemiological studies as well as several animal experiments. Therefore, manipulation of estrogen-caused signal pathways to inhibit ER-alpha and stimulate ER-beta may have preventive and therapeutic effect for obesity-associated colon cancer.

Changes in Estrogen Receptor ERα and ERβ Expression in Chicken (Gallus domesticus) Adrenal Gland during Short-fasting and Refeeding

Estrogen receptors have been found in the adrenal gland of rodents, monkeys, mares and sheep, indicating a connection between sex steroids and the activity of the adrenal gland. In the present study, the expression of estrogen receptors alpha (ERalpha) and beta (ERbeta) in the chicken adrenal gland during stress induced by 24 h fasting and after refeeding was determined using reverse transcription and the polymerase chain reaction (RT-PCR). The presence of both ER mRNAs in the adrenal gland of all examined groups was found. The relative expression of ERalpha mRNA was higher than ERbeta mRNA. There were no significant differences in ERalpha mRNA expression among the examined groups. On the contrary, we observed changes in ERbeta expression during stress conditions. These findings indicate different pathways of estrogen action in the avian adrenal gland. Furthermore, changes in ERbeta level suggest that this form of estrogen receptor plays a predominant role for estrogen action in the chicken adrenal gland during stress.

P2.16 Estrogen Receptors Alpha and Beta as Targets for Non-Small Cell Lung Cancer Hormonal Therapy

ABSTRACT Background Recent investigations demonstrate important role of estrogens in occurrence and progression of non-small cell lung cancer (NSCLC) as well as prognostic value of estrogen receptors (ER) alpha and beta in the tumor tissue. But the data about ER expression in the NSCLC differ significantly because of using semiquantitative methods for estimation only. To answer the question what is the significance of each type of the receptor as potential targets for antiestrogen therapy we have studied ERalpha and ERbeta expression in the NSCLC using the quantitative immunofluorescence methodology developed previously. Materials and methods NSCLC surgical specimens (97) were analyzed by flowcytometry. Primary antibodies were: anti-ERbeta 14C8, mouse IgG2a and IgG1 (Abcam); anti-ERalpha 1D5 (DAKO). Secondary antibody - FIT?-conjugated anti-mouse-IgG (F2772,Sigma). Number of specifically fluorescent cells was analyzed with Kolmogorov-Smirnov statistical approach. Three levels of ERbeta expression were compared: high - more than 50 % of the specifically fluorescent cells; moderate - 30-49 %; low - less than 30 %. Results 1.Expression of ERalpha and beta was reviled in about 90 % of NSCLC specimens. 2.Median of ERalpha level (22 %) was in 1·7-fold less then ERbeta level (37 %, p = 0,000002). 3.In women median of ERbeta level, but not ERalpha, was in 1·6-fold higher than in men (p = 0,008). 4.ERbeta level in men (32 %) and women (50 %) was higher in adenocarcinomas as compared with squamous-cell carcinomas in men (28 %): p = 0,0001 and 0,013 respectively. 5.ERalpha level in men (27 %) and women (22 %) was higher in adenocarcinomas as compared with squamous-cell carcinomas in men (16 %): p = 0,0003 and 0,016 respectively. 6. High and moderate level of ERbeta was revealed in 61 % of cases, while ERalpha - in 28 % only. 7. It was no coexpression of high ERalpha with low ERbeta level or any ERalpha expression with no ERbeta. Conclusion NSCLC is characterized by expression of ERbeta and ERalpha that is higher in adenocarcinomas than in squamous-cell carcinomas. ERbeta have main clinical relevance as potential target for antiestrogen therapy, because of higher level and frequency of expression than ERalpha. Generally, about half of adenocarcinoma and one third of squamous-cell carcinoma patients could benefit from adjuvant antiestrogen therapy. Supported by RFBR (Grants 10-04-00551-?,12-04-00028-?).

Estrogen receptor beta binds Sp1 and recruits a corepressor complex to the estrogen receptor alpha gene promoter

Human estrogen receptors alpha and beta are crucially involved in the regulation of mammary growth and development. Normal breast tissues display a relative higher expression of ER beta than ER alpha, which drastically changes during breast tumorogenesis. Thus, it is reasonable to suggest that a dysregulation of the two estrogen receptor subtypes may induce breast cancer development. However, the molecular mechanisms underlying the potential opposing roles played by the two estrogen receptors on tumor cell growth remain to be elucidated. In the present study, we have demonstrated that ER beta overexpression in breast cancer cells decreases cell proliferation and down-regulates ER alpha mRNA and protein content, along with a concomitant repression of estrogen-regulated genes. Transient transfection experiments, using a vector containing the human ER alpha promoter region, showed that elevated levels of ER beta down-regulated basal ER alpha promoter activity. Furthermore, site-directed mutagenesis and deletion analysis revealed that the proximal GC-rich motifs at -223 and -214 are critical for the ER beta-induced ER alpha down-regulation in breast cancer cells. This occurred through ER beta-Sp1 protein-protein interactions within the ER alpha promoter region and the recruitment of a corepressor complex containing the nuclear receptor corepressor NCoR, accompanied by hypoacetylation of histone H4 and displacement of RNA-polymerase II. Silencing of NCoR gene expression by RNA interference reversed the down-regulatory effects of ER beta on ER alpha gene expression and cell proliferation. Our results provide evidence for a novel mechanism by which overexpression of ER beta through NCoR is able to down regulate ER alpha gene expression, thus blocking ER alpha's driving role on breast cancer cell growth.

ERβ mRNA expression in ERα-negative and triple-negative breast cancers.

574 Background: ERα is the main prognostic and therapeutic marker in breast cancer (BC). About 30% of BC cases are negative for ER (ERα-) and do not benefit from antiestrogen therapy (TAM). We aim to study ER-beta (ERβ) expression in ERα- and triple negative (TN) cancers to explore alternate pathway of treatment in this cohort. Methods: We studied 67 ERα- BC cases including 44 TN together with 74 ERα +BC cases obtained from patients aged 29 to 97 years old between 2003 and 2010. The histology included 110 intraductal, 12 medullary and 19 other types. 78 cases were grade 3, 52 were grade 2, and 11 were grade 1. RNA was extracted from FFPE and mRNA levels of ERβ isoform and ERα were determined by real-time quantitative reverse transcription PCR. IHC stains were done on TMA the sections for ERα, PR, Her-2, Ki-67, CK5/6 and Cyclin D1. Results: ERβ isoforms were highly expressed in ERα-, TN, basal-like and HER2 type BC cases. ERβ2 was the major ERβ variant expressed. Ki-67 proliferating cells (&gt;20% nuclear staining) were mostly in ERα- rather than ERα+ cases (69.0% vs. 31.0%) as were cyclin D1- cells (82.2% vs. 17.8%). On the other hand, in ERα+ BC, ERα mRNA expression was consistently high and upregulated, and ERβ, low and down regulated, and the ratio of ERα+ to ERβ+ ranged from 3 to 100. ERβ1, 2 and 5 were co-expressed with ERα in 56%, 63%, and 30% of cases, respectively. Overall, ERβ mRNA levels did not show any significant correlation with age, tumor size, lymph node status and histological grades. Conclusions: ERβ-dependent proliferating tumor cells may render them more sensitive to TAM, and increase the effectiveness of TAM and its metabolites in ERα- and TN cases. Increased overall survival after adjuvant TAM ERα-BC may be directly related to ERβ over-expression. ERβ isoform is potential selective therapeutic target in a sub-cohort of ERα- BC. Additionally, when ERβ and ERα are co-expressed, ERβ appears to play a distinct role from its action in ERα- BC. [Table: see text]

Abstract 5555: Metastatic melanoma associated genes identified using the human tumor metastasis RT2 profiler PCR array

Abstract Metastatic melanoma is a complicated disease with growing rates of diagnosis and few clinical treatment options currently available. While melanoma results in only 5% of skin cancers, it is the cause of 75% of all skin cancer deaths. In 2008, the American Cancer Society (ACS) reported 62,480 new cases of melanoma. Of these individuals, 8,420 died, including 5,400 men and 3,020 women. According to the ACS for 2010, the 5-year survival rate for stage IV melanoma is 15% to 20% and the 10-year survival is 10% to 15%. To improve survival it is important to establish which genes are involved in the regulation of metastasis in melanoma as potential targets for prevention and/or treatment. Our laboratory compared the differences in the relative expression levels of metastasis genes from two human melanoma cell lines and a normal melanocyte cell line. The normal melanocyte cell line was assayed in duplicate and averaged as an inner plate control in order to validate the assay. Established melanoma, SK-mel-103 and SK-mel-147, were investigated. Template cDNA was prepared from total RNA from these lines using the Qiagen RNeasy Mini kit. The melanoma cell lines were both male and matched on GPR-30 and ER beta expression and B-RAF and N-RAS mutation status but they differed in G2 checkpoint and p16 mutation status. RT Array technology was utilized to compare the relative levels of mRNA from metastasis related genes expressed in SK-mel lines. The Human Tumor Metastasis RT2 Profiler™ PCR Array contains 84 primer pairs that amplify genes involved in human metastasis. Genes on this array include those that regulate cell adhesion, the extracellular matrix components, cell cycle, cell growth and proliferation, apoptosis, and transcription factors and regulators. The PCR array is a set of optimized real-time PCR primer assays on a 384-well plate for pathway focused genes and includes appropriate RNA quality controls. The quantitative PCR was run on the ABI 7900 HT using the real-time PCR cycling program. Total RNA from normal and melanoma tumors were characterized and the relative expression levels for each gene in the two melanoma samples were plotted against each other and against the normal cell line in scatter plots. Gene expression with controls samples was highly correlated. Genes involved in metastasis were up or down regulated in the melanoma cell lines compared to the normal cell lines. Upregulation of genes associated with DNA replication has previously been correlated with metastatic aggressiveness in melanoma cell lines. Conversely the down regulation of genes has been associated with an increase in cellular adhesion and melanocyte differentiation. This research identifies metastatic genes that contribute to the metastatic aggressiveness in the SK-mel metastatic melanoma cell lines. In the future we plan to examine the genes identified in this study for novel drug repurposing experiments. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5555. doi:1538-7445.AM2012-5555

Alteration in expression of estrogen receptor isoforms alpha and beta, and aromatase in the testis and its relation with changes in nitric oxide during aging in mice

The aim of present study was to investigate the changes in the testicular expression of aromatase, ER alpha, ER beta and iNOS protein and correlate these with serum testosterone and nitric oxide levels, to elucidate the role of estrogen and nitric oxide in the testis during aging. This study showed localization of aromatase and ER alpha mainly in the Leydig cell and showed close correlation of testicular aromatase level with circulating testosterone level suggesting that estrogen may be modulating testicular steroidogenesis. Localization ER alpha mainly in the mitotically active germ cell suggest possible role of estrogen in germ cell proliferation. This study showed basal level of nitric oxide during reproductively active period, whereas increased serum nitric oxide coincides with decreased testicular activity in old age. This study showed inverse correlation between aromatase and NO level. Treatment with either SNP or L-NAME on testicular steroidogenic factor (3-beta HSD/ StAR) or germ cell survival factor (Bcl2) showed that increased NO causes decreased steroidogenesis and increased germ cell apoptosis. In conclusion this study suggest that estrogen modulate steroidogenesis and germ cell survival in reproductively active period whereas in old age decreased estrogen concentration causes increased nitric oxide which in turn decreases testicular steroidogenesis and germ cell apoptosis.

Differential role of estrogen receptor beta in early versus metastatic non-small cell lung cancer.

Although women have an increased susceptibility to lung cancer, they also have a favorable clinical outcome. This may in part be due to female specific genetic and hormonal factors. In the present study, expression of ER-beta was investigated by immunohistochemistry using tissue samples from two cohorts: non-small cell lung cancer (NSCLC) diagnosed in 1999 in Manitoba and advanced NSCLC patients from the NCIC-CTG BR.18 trial. In the Manitoba cohort assessable tissue samples available in 79 patients (32 females and 47 males) and the majority (75%) had early stage disease. Fifty-one percent of patients expressed high levels of ER-beta (defined by ≥60, the median immunohistochemistry score) and its expression was comparable in males and females. The 3-year overall survival of the group was 53% and males had significantly worse survival compared to females (HR=2.37, 95%CI 1.15–4.91, P=0.02). Higher ER-beta 1 expression was associated with better survival in both univariate (HR=0.41, 95%CI 0.21–0.80, P=0.009) and in multivariate (HR=0.37, 95%CI 0.18–0.77, P=0.008) analysis. In the NCIC-CTG cohort that were more often later stage, assessable tissue samples from 48 cases were available however higher ER beta 1 expression correlated with poorer survival (HR= 1.94, 95%CI 1.01–3.75 P=0.047). These results suggest a differential impact of ER-beta 1 expression on clinical outcome by disease stage, that needs to be explored further and may explain contradictory observations reported in the literature.

Expression of estrogen receptors α and β in paratesticular tissues in boys operated on for unilateral cryptorchidism between the 1st and 4th years of life

SummaryBackgroundThe aim of this study was to assess the expression of estrogen receptors α and β in paratesticular tissues in a group of boys with and without cryptorchidism, and evaluation of karyotypes, localization, morphology and the major length of the undescended testes.Material/MethodsFifty boys (1–4 years old) with unilateral cryptorchidism were evaluated. Fifty healthy boys within the same age range, with inguinal hernia, served as a control group. Measurements concerning expression of ERα ERβ receptors were preformed using monoclonal mouse antibodies against human receptor α and β.ResultsIn the mesothelial layer, the expression of ERα was higher in the patients group with undescended testes and it was statistically significant (p=0.04). There was no difference in the expression of ERβ in this layer between groups. In the stromal cell layer there was statistically significant higher expression of ERβ (p<0.05) in the group of patients with undescended testes.ConclusionsThere was no difference between expressions of ERα in stromal cell layer. In the endothelial layer there was no difference in expression of ERα and ERβ. In the smooth muscle layer there was no expression of ERα in either group. The expression of ERβ in the smooth muscle layer was nearly identical in both groups. Undescended testes were generally found in the superficial inguinal pouch (n=46). The major lengths of the undescended testes were smaller in comparison to the testes positioned normally. In 9 of the cases the testes had different shape, and turgor deficit, and epididymides were smaller, dysplastic and separated from the testis.

Prognostic Significance of High Expression of ER-beta in Surgically Treated ER-Positive Breast Cancer Following Endocrine Therapy

PurposeThis study evaluated estrogen receptor (ER)-beta mRNA and ER-beta protein expression and its prognostic implications in hormone receptor-positive breast cancer.MethodsParaffin sections from 139 hormone receptor-positive breast cancer cases were prepared. The expression of ER-beta mRNA and protein were analyzed by branched-chain assay and immunohistochemistry (IHC), respectively.ResultsThe Allred score of ER-beta IHC was correlated with smaller tumor size (p=0.043), the Allred score of ER-alpha IHC (p<0.001), and the Allred score of progesterone receptor (PR) IHC (p=0.022) but not with the HER2 IHC score. ER-beta mRNA level was correlated with PR mRNA levels (p<0.001) but not with the Allred score of ER-beta IHC, ER-alpha IHC, and PR IHC, nor with the HER2 IHC score and ER-alpha mRNA level. In survival analysis, high expression of ER-beta mRNA was associated with worse disease-free survival along with poor differentiation, lymph node metastasis and absence of PR protein expression in univariate analysis (p=0.040, p=0.002, p=0.018, and p=0.007, respectively) and multivariate analysis (p=0.044, p=0.002, p=0.035, and p=0.007, respectively).ConclusionHigh expression of ER-beta mRNA is an independent predictor of disease recurrence in hormone-receptor-positive breast cancer.

P4-02-02: The Natural Fetal Estrogen Estetrol (E4), Causes Anti-Estrogenic Effects in Women with Endocrine-Responsive Positive Early Breast Cancer.

Abstract Background: Estetrol (E4) is a natural fetal estrogen which exerts estrogenic effects on reproductive organs and on the bone, and effectively reduces menopausal smyptoms. In contrast to other estrogens, however, E4 has estrogen-antagonistic effects on breast cancer cell lines in vitro and in the rat DMBA model, which would make it a suitable Hormone Replacement Therapy (HRT) in breast cancer patients, particularly in women who are being treated with aromatase inhibitors. Patients and Methods: We have investigated the effect of 14 days preoperative treatment with 20 mg E4 per day on tumor proliferation, apoptosis, ER-receptors, PgR receptor and several endocrine parameters in a prospective, randomised, double-blind, placebo-controlled, neo-adjuvant study in 15 pre- and 14 postmenopausal women with estrogen-receptor positive early breast cancer. Results: Estetrol induced a significant increase of SHBG, a significant decrease of FSH in postmenopausal women and no increase of gonadotrophins in premenopausal women. Estetrol had no effect on Ki67 expression and on apoptosis-related Bax and Bcl-2, but the apoptosis index in tumor tissue increased significantly. Systemic IGF-1 levels decreased significantly. Surprisingly the intratumoral epithelial ER-alpha expression decreased significantly, whereas the ER-beta expression showed a trend to increase. Conclusion: Our data suggest that E4 may be suitable and safe for HRT in women with spontaneous or induced menopausal symptoms, since apoptosis increases, IGF-1 decreases and no unfavourable effects are observed on Ki67, Bax and Bcl-2. The decrease of ER-alpha and the increase of ER-beta suggest a mechanism of action, explaining why the natural fetal estrogen E4 has estrogen-antagonistic effects on breast cancer tissue. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-02-02.

Variations in maternal care alter corticosterone and 17beta-estradiol levels, estrous cycle and folliculogenesis and stimulate the expression of estrogen receptors alpha and beta in the ovaries of UCh rats

BackgroundVariations in maternal care are associated with neonatal stress, hormonal disturbances and reproductive injuries during adulthood. However, the effects of these variations on sex hormones and steroid receptors during ovary development remain undetermined. This study aimed to investigate whether variations in maternal care are able to influence the hormonal profile, follicular dynamics and expression of AR, ER-alpha and ER-beta in the ovaries of UCh rat offspring.MethodsTwenty-four adult UCh rats, aged 120 days, were randomly divided into two groups (UChA and UChB) and mated. Maternal care was assessed from birth (day 0) to the 10th postnatal day (PND). In adulthood, twenty adult female rats (UChA and UChB offspring; n = 10/group), aged 120 days, were euthanized by decapitation during the morning estrus.ResultsUChA females (providing high maternal care) more frequently displayed the behaviors of carrying pups, as well as licking/grooming and arched back nursing cares. Also, mothers providing high care had elevated corticosterone levels. Additionally, offspring receiving low maternal care showed the highest estrous cycle duration, increased corticosterone and 17beta-estradiol levels, overexpression of receptors ER-alpha and ER-beta, increased numbers of primordial, antral and mature follicles and accentuated granulosa cell proliferation.ConclusionsOur study suggests that low maternal care alters corticosterone and 17beta-estradiol levels, disrupting the estrous cycle and folliculogenesis and differentially regulating the expression of ER-alpha and ER-beta in the ovaries of adult rats.