High ERβ Expression Research Articles

Crosstalk of ROS/RNS and autophagy in silibinin-induced apoptosis of MCF-7 human breast cancer cells in vitro.

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) play important roles in regulating cell survival and death. Silibinin is a natural polyphenolic flavonoid isolated from milk thistle with anti-tumor activities, but it was found to induce cytoprotective ROS/RNS in human breast cancer MCF-7 cells. Furthermore, treatment with silibinin down-regulates ERα expression in MCF-7 cells, and inducing both autophagy and apoptosis. In this study we explored the relationship between ER-associated pathways and RNS/ROS in MCF-7 cells. We also investigated the molecular mechanisms underlying the reciprocal regulation between ROS/RNS levels and autophagy in the death signaling pathways in silibinin-treated MCF-7 cells. Silibinin (100-300 μmol/L) dose-dependently increased ROS/RNS generation in MCF-7 cells (with high expression of ERα and low expression of ERβ) and MDA-MB-231 cells (with low expression of ERα and high expression of ERβ). Scavenging ROS/RNS significantly enhanced silibinin-induced death of MCF-7 cells, but not MDA-MB231 cells. Pharmacological activation or blockade of ERα in MCF-7 cells significantly enhanced or decreased, respectively, silibinin-induced ROS/RNS generation, whereas activation or block of ERβ had no effect. In silibinin-treated MCF-7 cells, exposure to the ROS/RNS donators decreased the autophagic levels, whereas inhibition of autophagy with 3-MA significantly increased ROS/RNS levels. We further showed that increases in ROS/RNS generation, ERα activation or autophagy down-regulation had protective roles in silibinin-treated MCF-7 cells. Under a condition of ERα activation, scavenging ROS/RNS or stimulating autophagy enhanced the cytotoxicity of silibinin. These results demonstrate the existence of two conflicting pathways in silibinin-induced death of MCF-7 cells: one involves the down-regulation of ERα and thereby augmenting the pro-apoptotic autophagy downstream, leading to cell death; the other involves the up-regulation of pro-survival ROS/RNS; and that the generation of ROS/RNS and autophagy form a negative feedback loop whose balance is regulated by ERα.

15 - Proffered Paper: In young women with atypical hyperplasia, high ERβ expression in background breast lobules correlates with decreased risk of future breast cancer

15 - Proffered Paper: In young women with atypical hyperplasia, high ERβ expression in background breast lobules correlates with decreased risk of future breast cancer

Abstract P5-08-27: Estrogen receptor beta expression is prognostic among chemotherapy-treated patients – Results from a population-based breast cancer cohort

Abstract Background and aim Estrogen receptor beta (ERβ) expression has been suggested to hold prognostic and predictive information, especially for endocrine treatment. The role of ERβ may depend on the expression of estrogen receptor alpha (ERα). The aim of this study was to evaluate ERβ expression in relation to tumor characteristics and risk for early events (disease-free survival, DFS) – overall and in different treatment groups, in a population-based cohort of primary breast cancer patients. Materials and methods Patients with primary breast cancer were invited at the preoperative visit between October 2002 and June 2012. After exclusion of patients who received preoperative treatment and patients with in situ carcinoma, the study population consisted of 1026 patients. Tumor specimens mounted in tissue microarrays were analyzed for ERβ expression using immunohistochemistry (antibody PPG5/10, Dako, dilution 1:20). Two cut-offs for positivity were evaluated (>10% and >75% of stained nuclei, respectively). Cox regression analyses yielding hazard ratios (HRs) with 95% confidence intervals (CIs) were adjusted for ERα status, tumor size, axillary lymph node involvement, histological grade, age at inclusion and body mass index. Events were defined as ipsi- or contralateral recurrences, regional or distant metastases. DFS was calculated from inclusion to event, non-breast cancer related death or last follow-up by June 30 2014, whichever came first. Patients were followed for up to 11 years (median follow-up 5.0 years for patients still at risk). Results ERβ expression was available for 911 patients (89%). ERβ positivity defined as >10% (ERβ10+, 92.1%) was positively associated with ERα (P<0.0001). ERβ10+ was not associated with DFS, overall or in patients who received tamoxifen and/or aromatase inhibitors. ERβ positivity defined as >75% (ERβ75+, 72.7%) was associated with ERα and PR positivity, lower histological grade, smaller invasive tumor size and no involvement of axillary nodes (all Ps≤0.03). In survival analyses among all patients, ERβ75+ was inversely associated with risk of early events (LogRank P=0.0005, adjHR 0.62: 95% CI 0.42-0.90; P=0.013). The magnitude of the association was larger in patients with ERα negative tumors (LogRankERα- P=0.011, adjHRERα- 0.42: 95% CI 0.17-1.02; P=0.05) compared to patients with ERα positive tumors (LogRankERα+ P=0.069, adjHRERα+ 0.74: 95% CI 0.48-1.14; P=0.18). In analyses stratified for chemotherapy, ERβ75+ expression was significantly associated with lower risk of early events among the 232 patients who had received chemotherapy (Log Rank P=0.0005, adjHR 0.31: 95% CI 0.15-0.63; P=0.001), but not among the 670 patients without chemotherapy (Log Rank P=0.14, adjHR 0.81: 95% CI 0.50-1.31; P=0.38). ERβ75+ was not associated with early events in patients with ERα+ tumors who received tamoxifen and/or aromatase inhibitors. Conclusion This study provides support for high tumor ERβ expression as a prognostic marker in breast cancer, for patients who received chemotherapy. Previous reports of ERβ as a predictor of endocrine therapy response could not be confirmed. Citation Format: Elebro K, Borgquist S, Rosendahl A, Markkula A, Simonsson M, Jirström K, Rose C, Ingvar C, Jernström H. Estrogen receptor beta expression is prognostic among chemotherapy-treated patients – Results from a population-based breast cancer cohort. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-08-27.

ERβ overexpression results in endocrine therapy resistance and poor prognosis in postmenopausal ERα-positive breast cancer patients

The aim of the present study was to investigate the role of estrogen receptor (ER) β in the prognosis of ERα-positive breast cancer in postmenopausal women, and its effect on the efficacy of endocrine therapy. Tissue specimens from 195 patients with postmenopausal breast cancer were analyzed. ERβ expression levels were detected using immunohistochemical staining. Kaplan-Meier analysis was performed to assess patient survival, and the difference in survival was analyzed using the log-rank test. Cox regression was utilized to evaluate prognostic factors. The results revealed that the disease-free survival rate decreased dramatically as ERβ expression levels increased in all postmenopausal ERα-positive breast cancer patients, and ERβ expression was identified to be an indicator of poor prognosis in cases of this disease. Similarly, in postmenopausal ERα-positive breast cancer patients undergoing endocrine therapy, high ERβ expression levels reduced the disease-free survival rate and were correlated with poor patient prognosis. However, in such patients who were not treated with endocrine therapy, disease-free survival rate and prognosis were not significantly affected by ERβ expression. In conclusion, ERβ overexpression led to endocrine therapy resistance and poor prognosis in postmenopausal ERα-positive breast cancer patients, suggesting that ERβ may affect breast cancer prognosis via an increase in endocrine therapy resistance.

ERβ expression and breast cancer risk prediction for women with atypias.

Estrogen receptor (ER) β is highly expressed in normal breast epithelium and a putative tumor suppressor. Atypical hyperplasia substantially increases breast cancer risk, but identification of biomarkers to further improve risk stratification is needed. We evaluated ERβ expression in breast tissues from women with atypical hyperplasia and association with subsequent breast cancer risk. ERβ expression was examined by immunohistochemistry in a well-characterized 171-women cohort with atypical hyperplasia diagnosed 1967-1991. Nuclear ERβ percent and intensity was scored in the atypia and adjacent normal lobules. An ERβ sum score (percent + intensity) was calculated and grouped as low, moderate, or high. Competing risks regression was used to assess associations of ERβ expression with breast cancer risk. After 15-year median follow-up, 36 women developed breast cancer. ERβ expression was lower in atypia lobules in than normal lobules, by percent staining and intensity (both P < 0.001). Higher ERβ expression in the atypia or normal lobules, evaluated by percent staining, intensity or sum score, decreased the risk of subsequent breast cancer by 2-fold (P = 0.04) and 2.5-fold (P = 0.006). High normal lobule ERβ expression conferred the strongest protective effect in premenopausal women: the 20-year cumulative incidence of breast cancer was 0% for women younger than 45 years with high versus 31% for low-moderate ERβ expression (P = 0.0008). High ERβ expression was associated with a significantly decreased risk of breast cancer in women with atypical hyperplasia. These data suggest that ERβ may be a useful biomarker for risk stratification and a novel therapeutic target for breast cancer risk reduction.

Correlation between epidermal growth factor receptor mutations and nuclear expression of female hormone receptors in non-small cell lung cancer: a meta-analysis.

Compared with male, female non-small cell lung cancer (NSCLC) patients have better response when treated with epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs), suggesting a potential association between female hormones and EGFR mutation. However, the results provided by previous studies were inconclusive and controversial. We sought to examine the link between the expression of nuclear female hormone receptors and EGFR mutations in NSCLC. Electronic databases were used to search the relevant articles. The involved hormone receptors included estrogen receptor (ER) and progesterone receptor (PR). The primary endpoint was the occurrence of ER/PR expression and EGFR mutation in NSCLC patients. Five studies fulfilled the criteria and were included in our analysis. Patients with high ER-β expression had higher positive EGFR mutation than low ER-β patients (44.2% vs. 23.7%), and there was a significant difference between the two groups [odds radio (OR) 3.44, 95% confidence interval (CI): 2.40-4.93, Z=6.72, P<0.001]. However, there is no significant correlation between EGFR mutations and ER-α (when included ER-α3, OR 1.20, 95% CI: 0.62-2.33, Z=0.55, P=0.58; and when included ER-α4, OR 1.18, 95% CI: 0.62-2.25, Z=0.51, P=0.61) or PR (OR 1.29, 95% CI: 0.40-4.10, Z=0.43, P=0.67). No significant publication bias was observed. High nuclear expression of ER-β, but not ER-α or PR is correlated with EGFR mutations in NSCLC. The underlying mechanism and potential translational relevance warrant further investigation.

Abstract P6-03-06: Therapeutic targeting of ERβ in triple negative breast cancer

Abstract Background: While the biological functions and clinical importance of ERα are well understood in breast cancer, much less is known about its most closely related family member, ERβ, particularly in the setting of triple negative disease. Additionally, the ability to therapeutically target ERβ in triple negative breast cancer (TNBC) has not been fully explored. Methods: Expression of ERβ protein was determined using a well characterized and validated ERβ specific monoclonal antibody that only recognizes the full-length form of this receptor (PPG5/10) in a cohort of 71 TNBCs. To further define the biological functions of ERβ in TNBC, novel ERβ expressing triple negative cell lines (MDA-MB-231 and Hs578T) were developed and comprehensively characterized at the level of global gene expression profiling, modulation of important biological pathways, cellular proliferation and response to targeted therapies. Results: In TNBCs from 71 patients, nuclear and cytoplasmic ERβ was detected at moderate to high levels in 24% and 32% of cases respectively. This moderate to high expression of both nuclear and cytoplasmic ERβ was associated with higher levels of Ki67. Of the 17 tumors expressing ERβ, 13 (76%) were negative for androgen receptor expression. In the triple negative MDA-MB-231-ERβ and Hs578T-ERβ cell lines, expression of ERβ led to inhibition of proliferation in response to both estrogen and multiple ERβ specific agonists. Microarray analysis and RT-PCR profiling of these cells revealed that estrogen and ERβ agonists highly induced the expression of multiple cystatins, a family of small secreted cysteine protease inhibitors, while suppressing the expression of many interleukins. Conditioned media isolated from estrogen or ERβ agonist treated MDA-MB-231-ERβ cells inhibited the proliferation rates and blocked TGFβ signaling in non-ERβ expressing TNBC cells, effects that were completely reversed following depletion of cystatins from the conditioned media. Conclusions: ERβ is expressed in a substantial proportion of TNBCs, and most do not express the androgen receptor. In TNBC, where targeted therapies are lacking, our data suggest that estrogen or ERβ specific agonists would be expected to elicit anti-tumor effects when ERβ is expressed. These tumor suppressive effects of ERβ appear to be mediated in part through the actions of cystatins, and their inhibition of TGFβ signaling, suggesting that this family of secreted proteins may represent novel biomarkers for monitoring ERβ specific drug responsiveness and/or patient outcomes. Citation Format: Jordan M Reese, Malayannan Subramaniam, Vera J Suman, Xianglin Wu, Vivian Negron, Anne Gingery, Kevin S Pitel, Sejal S Shah, Heather E Cunliffe, Ann E McCullough, Barbara A Pockaj, Thomas C Spelsberg, Matthew P Goetz, James N Ingle, John R Hawse. Therapeutic targeting of ERβ in triple negative breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-03-06.

Expression of estrogen-induced genes and estrogen receptor β in pancreatic neuroendocrine tumors: implications for targeted therapy.

The indolent nature and expression of progesterone receptor (PR), a well-known estrogen-induced gene, in a subset of pancreatic neuroendocrine tumors (PanNETs), raise the possibility of hormonal regulation in these tumors. Immunohistochemical expression of estrogen receptors (ERs) α and β as well as messenger RNA expression of estrogen-induced genes (PR, EIG121, IGF-1, IGF-1R, sFRP1, and sFRP4) by quantitative reverse transcription-polymerase chain reaction were examined in 131 World Health Organization grade G1 and G2 PanNETs and correlated their expression with clinicopathological features. Thirty-nine PanNETs (30%) showed high positive ERβ staining, and 87 cases (66%) had low positive ERβ staining; only 5 cases (4%) had no nuclear staining. Pancreatic neuroendocrine tumors with small size (P = 0.02), low World Health Organization grade (P = 0.02), and low American Joint Committee on Cancer stage (P = 0.006) more frequently showed high positive ERβ staining. Among the estrogen-induced genes studied, PanNETs had significantly higher expression of PR, EIG121, IGF-1, sFRP1, and sFRP4 compared with normal pancreas, independent of age or sex. High positive ERβ staining was associated with an increased expression of PR (P < 0.001) and EIG121 (P = 0.02). Our study showed that PanNETs with favorable prognostic features have higher ERβ expression, which is associated with up-regulated PR and EIG121 messenger RNA expression. Estrogen regulation in PanNETs could potentially help in risk stratification and provide a rational target for novel treatment strategies.

Effects on xenografts in nude mice of estrogen receptor β expression

Objective This study was to investigate the effect of estrogen receptor β (ERβ) on tumorigenesis of human breast cancer cell line in nude mice.Methods Breast cancer cell line MCF-7 (high expression of ERβ) was chose to show the tumorigenesis ablity after silence ERβ by small interfering RNA (siRNA).Results siRNA-ERβcan decrease the expression of ERβprotein in MCF-7 cells effectively.After silence ERββby siRNA,the tumorigenesis of MCF-7 cell were significantly enhanced.In ERβ-siRNA group,the tumor was papable on the 12th day,while in control-RNA group,the tumor was papable on the 27th day.The median survival time was 33 days in ERβ-siRNA group and 66 days in control-RNA group.Conclusion The ERβ gene can diminished the xenografts of MCF-7 cells in nudemice obviously. Key words: Estrogen receptor β; Breast cancer; Small interfering RNA; Nude mice

Expression pattern of estrogen receptors α and β and G-protein-coupled estrogen receptor 1 in the human testis

Estrogen signaling is considered to play an important role in spermatogenesis, spermiogenesis and male fertility. Estrogens can act via the two nuclear estrogen receptors ESR1 (ERα) and ESR2 (ERβ) or via the intracellular G-protein-coupled estrogen receptor 1 (GPER, formerly GPR30). Several reports on the localization and expression of all three receptors in the human testis have been published but are controversial particularly in case of ERα. Contrary to previous studies, we decided therefore to evaluate expression of all three receptors in the testis by a number of different methods and in comparison with MCF-7 cells. Using qPCR, we could show that mRNA expression of ERα is considerably lower and expression of ERβ and GPER much higher in the testis than in MCF-7 cells. RT-PCR after laser-assisted microdissection of tubular and interstitial compartments from normal and Sertoli cell only syndrome testes plus in situ hybridization and immunohistochemical analyses of the same samples demonstrated that there is very low expression of ERα in germ cells and in single interstitial cells, very high expression of ERβ in germ cells and Sertoli cells and high expression of GPER in interstitial cells and less in Sertoli cells.

Correlation between estrogen receptor β expression and the curative effect of endocrine therapy in breast cancer patients.

The aim of the present study was to investigate the association between the expression levels of estrogen receptor (ER)β and the curative effect of endocrine therapy in breast cancer patients. Cancer tissues were collected from 583 breast cancer patients between January 2000 and December 2010 and used for analysis. ERβ expression levels were determined using immunohistochemical staining. The Kaplan-Meier method was used for survival analysis and the log-rank test was conducted for difference analysis between survival times. In addition, Cox multivariate analysis was performed to analyze prognostic factors for breast cancer. In the immunohistochemical staining assay, a positive ERβ expression rate of <10% was defined as ERβ low expression, while >10% was defined as ERβ high expression. In patients expressing low levels of ERβ, the median tumor-free survival time of the patients who received endocrine therapy was significantly higher compared with that of the patients who did not receive endocrine therapy. By contrast, in patients with high ERβ expression levels, there was no significant difference in the median tumor-free survival time between the patients who received endocrine therapy and those who did not. In addition, compared with ERβ low expression patients, ERβ high expression patients had a significantly lower median tumor-free survival time. Furthermore, ERβ expression, human epidermal growth factor receptor 2 expression, tumor size, lymph node metastasis, postoperative chemotherapy, radiotherapy and endocrine therapy were identified to be independent prognostic factors for breast cancer. Therefore, high ERβ expression in breast cancer indicates poor prognosis for endocrine therapy.

Harmful effect of ERβ on BCRP‐mediated drug resistance and cell proliferation in ERα/PR‐negative breast cancer

The role of estrogen receptor β (ERβ) in breast cancer is still under investigation. Various studies have provided evidence that ERβ behaves as a tumor suppressor in breast cancer, whereas some studies of estrogen receptor α (ERα) negative breast cancer reported a positive correlation between high ERβ expression and poor prognostic phenotypes, such as induced proliferation, invasion and metastasis. In the present immunohistochemistry study of 99 ERα/progesterone receptor (PR)-negative breast cancer samples, nuclear expression of ERβ was positively associated with membranous expression of breast cancer resistance protein (BCRP), Ki67 (proliferation marker) and tumor size. Moreover, both endogenous and exogenous ERβ upregulated BCRP expression which induced BCRP-mediated drug resistance and enhanced proliferation of ERα-/PR- breast cancer cells in the presence of 17β-estradiol, whereas these effects were reversed by additional use of tamoxifen (TAM). In addition, the regulation of BCRP via specific binding between ERβ and estrogen response element (ERE) was demonstrated in an electrophoretic mobility shift assay. Overall, our findings manifest that ERβ might act as a tumor promoter of cell proliferation and BCRP-mediated drug resistance in ERα-/PR- breast cancer. TAM routinely used for patients with ERα+/PR+, ERα+/PR- and ERα-/PR+ breast cancer might also be effective in ERα-/PR- but ERβ+ breast cancer. Therefore, the detection of ERβ in clinic is valuable and should not be neglected in breast cancer, especially for the ERα-/PR- phenotype.

Emerging Significance of Estrogen Receptor β in Gliomas

Primary brain tumors are heterogeneous group of intracranial lesions that are categorized into different subtypes based on their close morphology to their parental cell. Gliomas are the most common and deadliest tumors that accounts for ~70-80% of total brain tumors and the etiology of brain tumors is not completely understood [1-3]. Recent evidence suggests that the incidence of brain tumors is significantly higher in men than in women during the periods of active menstrual cycle suggesting the possible protective role of female sex hormones in the development of brain tumors [4-6]. Furthermore, a lower glioma incidence was reported for females who used exogenous hormones. The existence of a gender bias and the involvement of steroid hormones in the development of gliomas highlight the importance of this field in the glioma pathobiology. Estrogens are the steroid hormones that play a crucial role during development and differentiation of central nervous system [7,8], and locally synthesized estrogens play an essential role in neuroprotective functions [9]. The biological effects of estrogens are mediated through their cognate receptors: estrogen receptor alpha [ERα] and estrogen receptor beta [ERβ] [10]. ERβ has quite a different function than ERα and ERβ functions as a tissue-specific tumour suppressor with antiproliferative actions [10,11]. Several studies demonstrated that most of the gliomas express ERβ with negative or weak expression of ERα. ERβ is highly expressed in low-grade astrocytomas and non-neoplastic brain tissues. In contrast, most of the high-grade tumors express low ERβ expression and this lower ERβ expression correlates with histological malignancy and poor survival of patients [12-14]. Lower ERβ expression is significantly associated with higher expression of cytoplasmic BAG-1 [a coregulator of ER signalling] and worse clinical outcome [14]. Further, high expression of ERβ was an independent favourable prognostic factor [15].

Different effects of ERβ and TROP2 expression in Chinese patients with early-stage colon cancer

Estrogen receptor beta (ERβ) and TROP2 expressed in colon carcinoma and might play an important role there. We explored the relationship of ERβ and TROP2 expression with the prognosis of early-stage colon cancer. ERβ and TROP2 levels were assessed by immunohistochemistry in normal mucosa and tumoral tissues from 220 Chinese patients with T(3)N(0)M(0) (stage IIa) and T(4)N(0)M(0) (stage IIb) colon cancer in the Cancer Center, Sun Yat-sen University, who underwent curative surgical resection between 1995 and 2003. The Cox proportional hazards regression model was applied to analyze the overall survival (OS) data, and the ROC curve, Kaplan-Meier estimate, log rank test, and Jackknife method were used to show the effect of ERβ and TROP2 expression at different stages of cancer. The 5-year survival rates were not significantly different between the patients with stage IIa and stage IIb colon cancer (83 vs. 80 %, respectively). The high expression of ERβ was related to decreasing OS in stage IIa and stage IIb colon cancer, while the high expression of TROP2 was related to decreasing OS in stage IIb colon cancer. The expression of ERβ and TROP2 has tumor-suppressive and tumor-promoting effect in stage IIa and stage IIb colon cancer, respectively.

Expression of oestrogen receptor β and prognosis of colorectal cancer

Background:Previous studies suggest that sex steroids influence colorectal cancer (CRC) carcinogenesis. The oestrogen receptor β (ERβ) is the predominantly expressed ER in the colon and loss of ERβ in CRC has been associated with advanced cancer stages.Methods:Information on vital status by the end of 2009 was obtained for 1262 CRC patients recruited between 2003 and 2007. The ERβ expression was immunohistochemically measured and associations of ERβ scores with overall survival (OS), disease-specific survival (DSS) and disease-free survival (DFS) were evaluated using Cox proportional hazard models adjusted for prognostic factors, such as tumour stage and second primary tumours.Results:Of the 1101 tumour samples with successful measurement, 535 were ERβ negative (48.6%), 381 (34.6%) showed moderate and 185 (16.8%) showed high ERβ expression. Compared with high ERβ expression, lack of ERβ was associated with higher cancer stages as well as greater tumour extent. In multivariate analyses, ERβ negativity was associated with an increased hazard ratio for death (HR=1.61, 95% CI 1.09–2.40, P=0.02), death attributed to CRC (HR=1.54, 95% CI 0.99–2.39, P=0.06) as well as a poorer DFS (DFS HR=1.64, 95% CI 1.23–3.36, P=0.04). The associations were stronger in stage I-III patients (OS HR=2.20, 95% CI 1.28–4.06, P=0.007, DSS HR=2.38, 95% CI 1.20–5.39, P=0.02, respectively).Conclusions:Lack of ERβ expression is associated with advanced cancer stages and independently associated with poor survival.

Role of Hormone Receptor Expression in Patients With Advanced-Stage Lung Cancer Treated With Chemotherapy

BackgroundEvidence that supports a role for hormonal status in lung cancer has been inconsistently reported and is still unclear. We retrospectively assessed the potential correlation between sex-linked hormone receptor expression and the clinical outcome of patients with advanced-stage lung cancer treated with chemotherapy. Patients and MethodsBased on tissue availability, 130 consecutive patients diagnosed at San Luigi Hospital from January 2008 to June 2010 were collected, including 24 small-cell lung cancer, 57 adenocarcinomas, 34 squamous cell carcinomas, 5 large-cell carcinomas, and 10 non–small-cell lung cancer–not otherwise specified. The immunohistochemical expression of estrogen receptors (ER-α and ER-β) and progesterone receptor, aromatase, epidermal growth factor receptor (EGFR), and excision repair cross-complementing 1 (ERCC1) was assessed. ResultsER-β nuclear expression was higher than ER-α and progesterone receptor, whose expression was null or weak (mainly in women). ER-β expression was significantly higher in patients with metastatic disease compared with all other disease stages (P = .02). EGFR expression was strongly correlated with non–small-cell lung cancer histology, being higher in squamous types and stage related. In men, aromatase positive cases had a worse outcome (P = .03) as well as in men with non–small-cell lung cancer and high ER-β expression. In the latter group, the combined aromatase negative and/or low ER-β expression and low ERCC1 and/or low ER-β expression showed a better outcome (P = .026; P = .03, respectively). ConclusionIn patients with advanced-stage lung cancer treated with chemotherapy, the prognostic and predictive role of sex-linked hormone receptor expression, if any, is of borderline significance and is restricted to selected subgroups of patients.

Abstract A39: Prevention of tobacco carcinogen-induced lung cancer in mice using antiestrogens

Abstract There is increasing evidence for steroid hormone effects in lung cancer. Estrogens are involved in lung cancer proliferation and progression, and human lung tumors express estrogen receptor β (ERβ) as well as aromatase, the enzyme which catalyzes the final step in 17-β-estradiol synthesis. We have previously demonstrated that high ERβ expression in lung tumors was an independent negative prognostic predictor of survival, and the contribution of aromatase expression resulted in further effects on survival in both men and women. To determine if the aromatase inhibitor anastrozole prevents the development of lung tumors induced by the tobacco carcinogen, NNK, alone or in combination with the ER antagonist fulvestrant, ovariectomized FVB/N female mice were exposed to NNK along with daily supplementation of 0.1mg androstenedione, the substrate for aromatase. Placebo control, anastrozole (0.1mg/kg/day; oral gavage) and/or fulvestrant (30mg/kg, 2X/week, s.c.) were administered in both an initiation model and a progression model of lung tumorigenesis. In the initiation model, the combination of fulvestrant and anastrozole was administered during NNK exposure and resulted in significantly fewer NNK-induced lung tumors (mean=0.5; range 0-1) compared to placebo (mean=4.6; range 2–8, P&amp;lt;0.001), fulvestrant alone (mean=3.4; range 1–4, P&amp;lt;0.001) or anastrozole alone (mean=2.8; range 0–5, P=0.002). Although a significant decrease in tumor size was not observed among treatment groups, a significant decrease in the cell proliferation index as assessed by Ki67 immunostaining within the tumors treated with anti-estrogens was observed. Beginning anti-estrogen treatment 9 weeks after NNK exposure in the lung tumor progression model, when preneoplastic areas had already formed, also yielded maximum anti-tumor effects with the combination group. In this model, tumor size was modulated by hormonal treatment with the smallest tumors observed in the combination treated group. These results suggest that targeting the estrogen pathway can inhibit lung cancer development during induction of damage to the airways by tobacco carcinogen exposure as well as after damage has occurred. In both animal models, aromatase expression was found mainly in macrophages infiltrating preneoplastic and tumor cells of the lungs, while ERβ was found in both macrophages and tumor cells. An important source of estrogen synthesis may be inflammatory cells that infiltrate the lungs in response to carcinogens, beginning early in the carcinogenesis process. ERβ expressed by inflammatory and neoplastic epithelial cells in the lung may signal in response to local estrogen production. In summary, the effects of combining two endocrine agents with different modes of actions suggest that complete blockade of estrogen action by inhibition of estrogen synthesis and down-regulation of ER has a greater effect on the prevention of tobacco carcinogen-induced murine lung tumorigenesis, and may be useful for lung cancer prevention in both males and females. Additionally, a greater understanding of the inflammatory state of the lung in relation to estrogen signaling is necessary to understand the early stages of lung tumorigenesis. This work was supported by NIH P50CA090440, SPORE in Lung Cancer to JMS and in part by the Comprehensive Cancer Center award P30CA047904.

Selective ERβ action of dehydroepiandrosterone for osteoblast cell line

To investigate the selective mechanism of dehydroepiandrosterone (DHEA) for osteoblast via ERβ. High expression of ERβ in hMG63-ERβ group (infected with pWPT-ERβ), gene silencing of ERβ in hMG63-shERβ group (infected with pLVTHM-GFP/ERβ-shRNA) and hMG63 group (control) were cultured and treated with 1×10(-7) mol/L DHEA, with or without U0126 and etoposide. The proliferation and apoptosis of hMG63 were evaluated by flow cytometry. The mRNA level of estrogen receptor subtype was detected by reverse transcription-PCR. The expression of ERβ in hMG63-ERβ group and hMG63-shERβ group were increased 7.39 times and decreased 17% compared with that in hMG63 group (control). DHEA could increase ERβ expression in hMG63 in each group, however, it did not influence the expression of ERα mRNA. When the level of ERβ was high, DHEA could accelerate the proliferation [proliferation index were (81.6 ± 7.6)% in hMG63-ERβ, (75.0 ± 5.3)% in hMG63, P < 0.05] and inhibit the apoptosis [apoptosis rate were (12.2 ± 1.6)% in hMG63-ERβ, (14.6 ± 1.5)% in hMG63, P < 0.01], which was blocked by U0126 [proliferation index were (33.2 ± 2.0)% in hMG63-ERβ, (41.2 ± 2.4)% in hMG63, apoptosis rate were (40.5 ± 4.3)% in hMG63-ERβ, (43.3 ± 4.1)% in hMG63, all P < 0.05]. When the expression of ERβ was silenced, DHEA could not inhibit the apoptosis of hMG63 anymore. DHEA selectively act on osteoblasts via the dominant expression of ERβ.

P1-508 Oestrogen receptor β expression in colorectal cancer

IntroductionThe oestrogen receptor β (ERβ) is the primarily expressed ER in the large intestine and has been found to have inhibitory effects on colon cancer cells. We therefore investigated, whether...

Prognostic value of novel biomarkers in astrocytic brain tumors: nuclear receptor co-regulators AIB1, TIF2, and PELP1 are associated with high tumor grade and worse patient prognosis

Estrogen receptors alpha (ERα) and beta (ERβ) and their co-regulatory proteins are key components of complex signaling networks that specifically regulate the growth and development of various tissues and tumors. Still, their protein expression profiles and possible role in the pathogenesis of astrocytic tumors remain largely unknown. The purpose of the present study is to evaluate the differential protein expression of ΕRα, ERβ, and their co-activators, AIB1, TIF2, and PELP1 in astrocytic tumors of World Health Organization (WHO) grade II-IV, using immunohistochemistry. Potential correlations with clinicopathological parameters and patient prognosis were also explored. ERα protein expression was undetectable while ERβ levels were significantly decreased with progression of tumor grade (P < 0.001). High expression of ERβ was an independent favorable prognostic factor on multivariate analysis (P = 0.003). Expression of AIB1, TIF2, and PELP1 was not correlated with ERβ expression and followed an opposite trend, with increasing levels in high-grade relative to low-grade tumors (P < 0.001). Univariate survival analysis revealed that high AIB1, TIF2, and PELP1 expression was associated with worse prognosis (P = 0.049, P = 0.033, and P = 0.020, respectively). ERβ and ER co-activators AIB1, TIF2, and PELP1 appear to play an important role in the pathogenesis and progression of astrocytic tumors and might have prognostic significance. The mechanisms underlying their involvement in astrocytic tumorigenesis, as well as their utility for prognostic and therapeutic purposes merit further investigation.