Steroid hormones and growth factors affect lung cancer, and it is possible they act in concert to influence patient outcome.
Primary lung tumors and normal lung tissue were analyzed for expression and localization of estrogen receptor α and β–1 ERα and ERβ), aromatase, progesterone receptor (PR), and epidermal growth factor receptor (EGFR).
Tumors expressed higher levels of ERβ compared to matched normal lung, while the reverse was true of PR. High cytoplasmic ERβ expression was identified as an independent negative prognostic predictor of overall survival (OS) (HR=1.67), and low total PR was identified as an independent negative predictor of time to progression (TTP) (HR=1.59). After adjusting for stage, age, sex and smoking, combined high cytoplasmic ERβ and low total PR showed enhanced effects on OS (HR=2.64) and on TTP (HR=6.02). Further effects on OS were observed when EGFR expression was included (HR=5.32). Patients with low cytoplasmic ERβ, low aromatase, low EGFR and high total PR had shorter OS than patients with the opposite pattern (HR= 6.60). Contribution of these markers to survival showed no significant sex differences in a multivariable model. ERα was elevated in tumors but was not predictive of survival, and appears to represent a variant ERα protein that is only recognized by a C-terminal antibody.
Hormonal and EGFR pathways together may contribute to lung cancer prognosis. Lung tumors with high ERβ–1 /low PR may define patients with aggressive biology. A validation study is necessary to fully assess the predictive value of these markers.
estrogen receptor; progesterone receptor; aromatase; epidermal growth factor receptor; lung cancer
In order to study estrogen-driven microenvironment associated with type 1 endometrial carcinoma, we evaluated estrogen receptors (ERs), aromatase, and cyclooxygenase II (COX2) molecular and immunohistochemical profiles with correlation to clinicopathological features. We investigated aromatase, ERα, ERβ, and COX2 expression at the mRNA and protein levels using quantitative real-time PCR and immunohistochemical method in 51 endometrial carcinomas and 16 normal endometria. All the studied tumors, as well as normal endometria, expressed ERα, ERβ, and COX2 mRNAs. Five endometrial carcinoma tissues and one normal endometrium showed no aromatase mRNA expression. The majority of tumors expressed ERα (82 %), aromatase (80 %), and COX2 (88 %) proteins. Forty-one percent of the studied tumors were ERβ-negative. ERα and ERβ showed significantly decreased mRNA and protein expression levels in endometrial carcinoma as compared to normal endometrium. An opposite trend was shown for COX2 and aromatase proteins. ERα expression correlated positively with COX2 expression at both mRNA and protein levels (P < 0.005, r = 0.398; P < 0.0005, r = 0.510, respectively). There was also a positive correlation between COX2 and aromatase expression in cancer tissue (P < 0.002, r = 0.433 for transcriptional level; P < 0.0005, r = 0.614 for protein level). We observed positive correlations between ERβ and ERα, as well as between ERβ and COX2 at the transcriptional level only (P < 0.0005, r = 0.644; P < 0.002, r = 0.444, respectively). Negative correlations were found between pT category of primary tumor and levels of ERα and ERβ transcripts (P < 0.02, r = −0.332; P < 0.02, r = −0.348, respectively). A negative association between ERβ and the International Federation of Gynecology and Obstetrics (FIGO) staging was also found. The growth of EC1 with the presence of ERα and overexpression of aromatase and COX2 is dependent on estrogens. We believe that ERβ may be considered as a potential marker in the progression of disease in endometrial cancer patients.
ERs (ERα, ERβ); Aromatase; COX2; Type 1 endometrial cancer
Lung cancer is the most common cause of cancer mortality in male and female patients in the US. Although it is clear that tobacco smoking is a major cause of lung cancer, about half of all women with lung cancer worldwide are never-smokers. Despite a declining smoking population, the incidence of non-small cell lung cancer (NSCLC), the predominant form of lung cancer, has reached epidemic proportions particularly in women. Emerging data suggest that factors other than tobacco, namely endogenous and exogenous female sex hormones, have a role in stimulating NSCLC progression. Aromatase, a key enzyme for estrogen biosynthesis, is expressed in NSCLC. Clinical data show that women with high levels of tumor aromatase (and high intratumoral estrogen) have worse survival than those with low aromatase. The present and previous studies also reveal significant expression and activity of estrogen receptors (ERα, ERβ) in both extranuclear and nuclear sites in most NSCLC. We now report further on the expression of progesterone receptor (PR) transcripts and protein in NSCLC. PR transcripts were significantly lower in cancerous as compared to non-malignant tissue. Using immunohistochemistry, expression of PR was observed in the nucleus and/or extranuclear compartments in the majority of human tumor specimens examined. Combinations of estrogen and progestins administered in vitro cooperate in promoting tumor secretion of vascular endothelial growth factor and, consequently, support tumor-associated angiogenesis. Further, dual treatment with estradiol and progestin increased the numbers of putative tumor stem/progenitor cells. Thus, ER- and/or PR-targeted therapies may offer new approaches to manage NSCLC.
Progesterone; Estrogen; Steroid hormone receptor; Non-small cell lung cancer; VEGF; Progenitor cells; Cancer stem cells; Angiogenesis
Estrogen signaling is critical in the progression of tumors that bear estrogen receptors. In most patients with breast cancer, inhibitors that block interactions of estrogen with its receptors or suppress the production of endogenous estrogens are important interventions in the clinic. Recent evidence now suggests that estrogen also contributes to the pathogenesis of non–small cell lung cancer (NSCLC). We used a human lung cancer xenograph model system to analyze the effect of aromatase or estradiol on tumor growth. We further examined the level of protein expression of aromatase in 422 patients with NSCLC using a high-density tissue microarray. Results were confirmed and validated on an independent patient cohort (n = 337). Lower levels of aromatase predicted a greater chance of survival in women 65 years and older. Within this population, the prognostic value of aromatase was greatest in earlier stage lung cancer (stage I/II). In addition, for women with no history of smoking, lower aromatase levels were a strong predictor of survival. Our findings implicate aromatase as an early-stage predictor of survival in some women with NSCLC. We predict that women whose lung cancers have higher levels of aromatase might be good candidates for targeted treatment with aromatase inhibitors.
Lung cancer has become increasingly common in women, and gender differences in the physiology and pathogenesis of the disease have suggested a role for estrogens. In the lung recent data have shown local production of estrogens from androgens via the action of aromatase enzyme and higher levels of estrogen in tumor tissue as compared with surrounding normal lung tissue. High levels of aromatase expression are also maintained in metastases as compared with primary tumors. Consistent with these findings, clinical studies suggest that aromatase expression may be a useful predictive biomarker for prognosis in the management of non-small cell lung cancer (NSCLC), the most common form of lung malignancy. Low levels of aromatase associate with a higher probability of long-term survival in older women with early stage NSCLC. Treatment of lung NSCLC xenografts in vivo with an aromatase inhibitor (exemestane) alone or combined with standard cisplatin chemotherapy elicits a significant reduction in tumor progression as compared to paired controls. Further, lung cancer progression is also governed by complex interactions between estrogen and growth factor signaling pathways to stimulate the growth of NSCLC as well as tumor-associated angiogenesis. We find that combination therapy with the multitargeted growth factor receptor inhibitor vandetanib and the estrogen receptor antagonist fulvestrant inhibit tumor growth more effectively than either treatment administered alone. Thus, incorporation of antiestrogen treatment strategies in standard antitumor therapies for NSCLC may contribute to improved patient outcome, an approach that deserves to be tested in clinical trials.
non-small cell lung cancer (NSCLC); aromatase; CYP19; estrogen receptor (ER); epidermal growth factor receptor (EGFR); vascular endothelial growth factor (VEGF) receptor; anastrazole; exemestane; fulvestrant; vandetanib
Lung cancer is the leading cause of cancer-related deaths in both men and women worldwide. Despite advances in treatment, patients have few effective therapeutic options and survival rates remain low. Emerging evidence suggests that the hormones estrogen and progesterone play a key role in the progression of non-small-cell lung cancer (NSCLC). The aromatase enzyme, which is responsible for a key step in estrogen biosynthesis, elicits higher levels of estrogen in lung tumors as well as in metastases compared with nonmalignant tissues. Thus, aromatase may prove to be a key predictive biomarker for treatment of NSCLC. Epidemiologic and preclinical data show estrogens play a critical role in lung tumor development and progression. Two estrogen receptors, α and β, are expressed in normal and in cancerous lung epithelium, and estrogen promotes gene transcription that stimulates cell proliferation and inhibits cell death. Furthermore, expression of both forms of estrogen receptor, progesterone receptor and aromatase in NSCLC specimens has been correlated with worse clinical outcomes. Combination therapies that include estrogen receptor downregulators and aromatase inhibitors are currently being assessed in Phase I–II clinical trials among patients with advanced NSCLC. Results will help guide future lung cancer management decisions, with a goal of achieving more effective and less toxic treatments for patients.
The biological roles of estrogen receptor 1 (ERS1), estrogen receptor 2 (ERS2), and aromatase (CYP19A1) genes in the development of non-small cell lung cancer (NSCLC) is unclear, as is the use of their expression as a prognostic factor. The aim of this study was to investigate the prognostic value of estrogen receptors and aromatase mRNA expression, along with aromatase protein concentration, in resected NSCLC patients. Tumor and non-tumor lung tissue samples were analyzed for the mRNA expression of ERS1, ERS2 and CYP19A1 by RT-PCR. Aromatase concentration was measured with an ELISA. A total of 96 patients were included. ERS1 expression was significantly higher in non-tumor tissue than in tumor samples. Two gene expression categories were created for each gene (and protein): high and low. ERS1 high category showed increased overall survival (OS) when compared to the low expression category. Aromatase protein concentration was significantly higher in tumor samples. Higher ERS1 expression in tumor tissues was related to longer overall survival. The analysis of gene expression combinations provides evidence for longer OS when both ERS1 and ERS2 are highly expressed. ESR1, alone or in combination with ERS2 or CYP19A1, is the most determining prognostic factor within the analyzed 3 genes. It seems that ERS1 can play a role in NSCLC prognosis, alone or in combination with other genes such as ERS2 or Cyp19a1. ERS2 in combination with aromatase concentration could have a similar function.
Estrogens play a pivotal role in the development and progression of prostate cancer (PCa). Their actions are mediated by estrogen receptors (ERs), particularly ERβ in the prostate epithelium. With the discovery of ERβ isoforms, data from previous studies that focused principally on the wild-type ERβ (ERβ1) may not be adequate in explaining the still controversial role of ERβ(s) in prostate carcinogenesis. In this study, using newly generated isoform-specific antibodies, immunohistochemistry (IHC) was performed on a tumor microarray comprised of 144 specimens. IHC results were correlated with pathological and clinical follow-up data to delineate the distinct roles of ERβ1, ERβ2, and ERβ5 in PCa. ERβ2 was commonly found in the cytoplasm and was the most abundant isoform followed by ERβ1 localized predominantly in the nucleus, and ERβ5 was primarily located in the cytoplasm. Logistic regression analyses demonstrated that nuclear ERβ2 (nERβ2) is an independent prognostic marker for prostate specific antigen (PSA) failure and postoperative metastasis (POM). In a Kaplan–Meier analysis, the combined expression of both nERβ2 and cytoplasmic ERβ5 identified a group of patients with the shortest POM-free survival. Cox proportional hazard models revealed that nERβ2 predicted shorter time to POM. In concordance with IHC data, stable, ectopic expression of ERβ2 or ERβ5 enhanced PCa cell invasiveness but only PCa cells expressing ERβ5 exhibited augmented cell migration. This is the first study to uncover a metastasis-promoting role of ERβ2 and ERβ5 in PCa, and show that the two isoforms, singularly and conjointly, have prognostic values for PCa progression. These findings may aid future clinical management of PCa.
Oestrogen receptor beta (ERβ) modulates ERα activity; wild type ERβ (ERβ1) and its splice variants may therefore impact on hormone responsiveness of breast cancer. ERβ2/ERβcx acts as a dominant negative inhibitor of ERα and expression of ERβ2 mRNA has been proposed as a candidate marker for outcome in primary breast cancer following adjuvant endocrine therapy. We therefore now assess ERβ2 protein by immunostaining and mRNA by quantitative RT-PCR in relation to treatment outcome.
ERβ2-specific immunostaining was quantified in 141 primary breast cancer cases receiving adjuvant endocrine therapy, but no neoadjuvant therapy or adjuvant chemotherapy. The expression of mRNA for ERβ2/ERβcx was measured in 100 cases by quantitative RT-PCR. Statistical analysis of breast cancer relapse and breast cancer survival was performed using Kaplan Meier log-rank tests and Cox's univariate and multivariate survival analysis.
High ERβ2 immunostaining (Allred score >5) and high ERβ2 mRNA levels were independently associated with significantly better outcome across the whole cohort, including both ERα positive and negative cases (Log-Rank P < 0.05). However, only ERβ2 mRNA levels were significantly associated with better outcome in the ERα + subgroup (Log-Rank P = 0.01) and this was independent of grade, size, nodal status and progesterone receptor status (Cox hazard ratio 0.31 P = 0.02 for relapse; 0.17 P = 0.01 for survival). High ERβ2 mRNA was also associated with better outcome in node negative cases (Log Rank P < 0.001).
ERβ2 protein levels were greater in ERα positive cases (T-test P = 0.00001), possibly explaining the association with better outcome. Levels of ERβ2 protein did not correlate ERβ2 mRNA levels, but 34% of cases had both high mRNA and protein and had a significantly better outcome (Log-Rank relapse P < 0.005).
High ERβ2 protein levels were associated with ERα expression. Although most cases with high ERβ2 mRNA had strong ERβ2 immunostaining, mRNA levels but not protein levels were independently predictive of outcome in tamoxifen-treated ERα + tumours. Post-transcriptional control needs to be considered when assessing the biological or clinical importance of ERβ proteins.
The inhibition of estrogen receptor (ER) α action with the ER antagonist tamoxifen is an established treatment in the majority of breast cancers. De novo or acquired resistance to this therapy is common. Expression of ERβ in breast tumors has been implicated as an indicator of tamoxifen sensitivity. The mechanisms behind this observation remain largely uncharacterized. In the present study, we investigated whether ERβ can modulate pathways implicated in endocrine resistance development.
T47-D and MCF-7 ERα-expressing breast cancer cells with tetracycline-regulated expression of ERβ were used as a model system. Expression levels and activity of known regulators of endocrine resistance were analyzed by performing quantitative polymerase chain reaction assays, Western blot analysis and immunostaining, and sensitivity to tamoxifen was investigated by using a cell proliferation kit.
Expression of ERβ in ERα-positive T47-D and MCF-7 human breast cancer cells resulted in a decrease in Akt signaling. The active form of an upstream regulator of Akt, proto-oncogene c-ErbB-2/receptor tyrosine kinase erbB-3 (HER2/HER3) receptor dimer, was also downregulated by ERβ. Furthermore, ERβ increased expression of the important inhibitor of Akt, phosphatase and tensin homologue deleted on chromosome 10 (PTEN). Importantly, ERβ expression increased the sensitivity of these breast cancer cells to tamoxifen.
Our results suggest a link between expression of ERβ and endocrine sensitivity by increasing PTEN levels and decreasing HER2/HER3 signaling, thereby reducing Akt signaling with subsequent effects on proliferation, survival and tamoxifen sensitivity of breast cancer cells. This study supports initiatives to further investigate whether ERβ presence in breast cancer samples is an indicator for endocrine response. Current therapies in ERα-positive breast cancers aim to impair ERα activity with antagonists or by removal of endogenous estrogens with aromatase inhibitors. Data from this study could be taken as indicative for also using ERβ as a target in selected groups of breast cancer.
The impact of interactions between the two estrogen receptor (ER) subtypes, ERα and ERβ, on gene expression in breast cancer biology is not clear. The goal of this study was to examine transcriptomic alterations in cancer cells co-expressing both receptors and the association of gene expression signatures with disease outcome.
Transcriptional effects of ERβ overexpression were determined in a stably transfected cell line derived from ERα-positive T-47D cells. Microarray analysis was carried out to identify differential gene expression in the cell line, and expression of key genes was validated by quantitative polymerase chain reaction. Microarray and clinical data from patient samples were then assessed to determine the in vivo relevance of the expression profiles observed in the cell line.
A subset of 14 DNA replication and cell cycle-related genes was found to be specifically downregulated by ERβ. Expression profiles of four genes, CDC2, CDC6, CKS2, and DNA2L, were significantly inversely correlated with ERβ transcript levels in patient samples, consistent with in vitro observations. Kaplan-Meier analysis revealed better disease outcome for the patient group with an expression signature linked to higher ERβ expression as compared to the lower ERβ-expressing group for both disease-free survival (p = 0.00165) and disease-specific survival (p = 0.0268). These findings were further validated in an independent cohort.
Our findings revealed a transcriptionally regulated mechanism for the previously described growth inhibitory effects of ERβ in ERα-positive breast tumor cells and provide evidence for a functional and beneficial impact of ERβ in primary breast tumors.
A role for estrogen signaling in urothelial carcinoma of the bladder (UCB) is suggested to be associated with more advanced disease with worse outcomes in women. Estrogen receptor β (ERβ) is the predominant receptor in bladder tissues. We aimed to ascertain whether ERβ correlates with clinicopathological predictors of aggressive bladder cancer and worse survival outcomes. ERβ was measured by immunohistochemistry in malignant and adjacent benign bladder tissues in patients (N=72) with UCB who underwent radical cystectomy. ERβ expression was tested for statistical association with clinicopathological variables and patient survival. ERβ expression was determined in bladder cancer cell lines, and the effects of the selective estrogen modulator tamoxifen and the ERβ agonist diarylpropionitrile on cell growth were determined. The ERβ level was significantly higher in malignant vs. benign urothelium (P<0.001) and was strongly associated with aggressive tumor histology characterized by lymphovascular (P=0.008) and perineural (P=0.006) invasion, and clinical histories of pelvic irradiation (P=0.005), hydronephrosis (P=0.022) and no intravesical chemotherapy (P=0.038). All patients with a high (>70%) percentage of ERβ positivity in tissue with >3-month follow-up developed recurrent disease (P=0.009). Higher ERβ level was predictive of worse recurrence-free and overall survival following cystectomy, after adjustment for tumor stage, and remained significantly associated with recurrence-free survival in the multivariable analysis including tumor stage, nodal stage and lymphovascular invasion. Activation of ERβ in bladder cancer cell lines led to significant increases in proliferation, while pharmacological inhibition with tamoxifen blocked cell growth. Our study supports a role for ERβ in aggressive UCB. Pharmacological targeting of ERβ warrants further investigation as a therapeutic strategy in UCB.
epigenetic; hormonal; urothelial; transitional cell
New, third-generation aromatase inhibitors (AIs) have proven comparable or superior to the anti-estrogen tamoxifen for treatment of estrogen receptor (ER) and/or progesterone receptor (PR) positive breast cancer. AIs suppress total body and intratumoral estrogen levels. It is unclear whether in situ carcinoma cell aromatization is the primary source of estrogen production for tumor growth and whether the aromatase expression is predictive of response to endocrine therapy. Due to methodological difficulties in the determination of the aromatase protein, COX-2, an enzyme involved in the synthesis of aromatase, has been suggested as a surrogate marker for aromatase expression.
Primary tumor material was retrospectively collected from 88 patients who participated in a randomized clinical trial comparing the AI letrozole to the anti-estrogen tamoxifen for first-line treatment of advanced breast cancer. Semi-quantitative immunohistochemical (IHC) analysis was performed for ER, PR, COX-2 and aromatase using Tissue Microarrays (TMAs). Aromatase was also analyzed using whole sections (WS). Kappa analysis was applied to compare association of protein expression levels. Univariate Wilcoxon analysis and the Cox-analysis were performed to evaluate time to progression (TTP) in relation to marker expression.
Aromatase expression was associated with ER, but not with PR or COX-2 expression in carcinoma cells. Measurements of aromatase in WS were not comparable to results from TMAs. Expression of COX-2 and aromatase did not predict response to endocrine therapy. Aromatase in combination with high PR expression may select letrozole treated patients with a longer TTP.
TMAs are not suitable for IHC analysis of in situ aromatase expression and we did not find COX-2 expression in carcinoma cells to be a surrogate marker for aromatase. In situ aromatase expression in tumor cells is associated with ER expression and may thus point towards good prognosis. Aromatase expression in cancer cells is not predictive of response to endocrine therapy, indicating that in situ estrogen synthesis may not be the major source of intratumoral estrogen. However, aromatase expression in combination with high PR expression may select letrozole treated patients with longer TTP.
Sub-study of trial P025 for advanced breast cancer.
This study is to determine the expression of estrogen receptor beta (ERβ) in breast cancer patients and to evaluate its relationship with clinicopathological parameters of breast cancer and its effects on the prognosis of breast cancer patients. Paraffin-embedded primary tumor tissue sections from 490 breast cancer patients were collected consecutively from January 2000 to December 2010. They had complete clinical data and follow-up records. Immunohistochemical staining was conducted to determine ERβ expression. The Kaplan-Meier method was used for survival analysis. Difference in survival was analyzed by the Log-Rank test. The Cox proportional hazard model was performed to evaluate the prognostic value of ERβ expression in breast cancer patients. The ERβ high and over expression rate in 490 breast patients was 22.4% (110/490). ERβ expression was not associated with clinicopathological parameters of breast cancer. The mean survival time in patients with ERβ negative expression, ERβ low expression, ERβ high expression and ERβ over expression was 9.9 years, 9.2 years, 8.6 years and 5.6 years. Statistically, patients with ERβ high and over expression had significantly shorter disease-free survival (DFS) time compared with the patients with ERβ negative and low expression. The Cox multivariate analysis revealed that ERβ high and over expression, the pathologic stages of tumor and chemotherapy were the independent predictors for poor DFS in breast cancer patients. ERβ expression is an independent prognostic factor of breast cancer patients and its high and over expression indicates poor prognosis of breast cancer. There was no correlation between ERβ expression and clinicopathological parameters in breast cancer.
ERβ; breast cancer; prognosis
In humans, aromatase (CYP19) gene expression is regulated via alternative promoters. Activation of each promoter gives rise to a CYP19 mRNA species with a unique 5′-untranslated region. Inhibition of aromatase has been reported to downregulate lung tumor growth. The genetic basis for CYP19 gene expression and aromatase activity in lung cancer remains poorly understood. We analyzed tissues from 15 patients with non-small cell lung cancer (NSCLC) to evaluate CYP19 promoter usage and promoter-specific aromatase mRNA levels in NSCLC tumor tissues and adjacent non-malignant tissues. CYP19 promoter usage was determined by multiplex RT-PCR and aromatase mRNA levels were measured with real-time RT-PCR. In non-malignant tissues, aromatase mRNA was primarily derived from activation of CYP19 promoter I.4. Although promoter I.4 usage was also dominant in tumor tissues, I.4 activation was significantly lower compared with adjacent non-malignant tissues. Activity of promoters I.3, I.1 and I.7 was significantly higher in tumor tissues compared with non-malignant tissues. In 4 of 15 cases of non-small cell lung cancer, switching from CYP19 promoter I.4 to the alternative promoters II, I.1 or I.7 was observed. In 9 cases, there were significantly higher levels of aromatase mRNA in lung tumor tissues compared with adjacent non-malignant tissues. These findings suggest aberrant activation of alternative CYP19 promoters that may lead to upregulation of local aromatase expression in some cases of NSCLC. Further studies are needed to examine the impact of alternative CYP19 promoter usage on local estrogen levels and lung tumor growth.
non-small cell lung cancer; estrogen; aromatase; CYP19; promoter; promoter usage
This study is to investigate the estrogen receptor β (ERβ) expression in molecular subtypes of breast cancer and clinic significance of ERβ expression.
The ERβ expression was detected in 730 cases of breast cancer tissue specimens by immunohistochemistry. Twenty-one patients were censored during 2–10 years follow-up. The difference in ERβ expression was analyzed by Pearson Chi-square Test. Its correlation with estrogen receptor α (ERα), progesterone receptor (PR) and human epidermal growth factor receptor 2 (Her-2) was analyzed by Spearman rank correlation. The accumulative tumor-free survival rate was calculated by Kaplan-Meier method and difference in survival rate was analyzed by Log-rank test. Cox regression was used for multi-factor analysis.
The ERβ expression was significantly different among the molecular subtypes of breast cancer (P < 0.05). The ERβ expression in breast cancer was positively correlated with Her-2 (P < 0.05) while it had no correlation with ERα and Her-2. The expression of ERα was negatively correlated with Her-2 (P < 0.01) whereas positively correlated with PR (P < 0.01). The expression of PR was negatively correlated with Her-2 (P < 0.05). The tumor-free survival rate in patients with positive ERβ expression was significantly lower than that in patients with negative ERβ expression.
Positive ERβ expression is a poor prognostic factor of breast cancer.
The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1084557586106833
Breast cancer; ERβ; Molecular subtypes
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.
breast cancer; estrogen receptor β; curative effect
Factors associated with increased estrogen synthesis increase breast cancer risk. Increased aromatase and estrogen receptor α (ERα) in both normal epithelium and ductal carcinoma in situ lesions are found in conjunction with breast cancer, leading to the idea that altered estrogen signaling pathways predispose the mammary gland to cancer development. Here, we developed a transgenic mouse that conditionally expresses aromatase in the mammary gland, and used it along with a deregulated ERα expression model to investigate the molecular pathways involved in the development of mammary gland preneoplasia and carcinoma. Both increased ERα and aromatase expression led to the development of preneoplasia, but increased preneoplasia, in addition to carcinoma, was found in aromatase over-expressing mice. Increased prevalence of mammary pathological changes in mice expressing aromatase correlated with increased Cyclin E and Cyclin-dependent kinase 2 expression. Gain of both ERα and aromatase increased expression of ERα and progesterone receptor, but aromatase produced a higher increase than ERα, accompanied by higher levels of downstream target genes cyclin D1, c-Myc and RANKL. In summary, while gain of both ERα and aromatase activate abnormal growth pathways in the mammary gland, aromatase induced a wider range of abnormalities that was associated with a higher prevalence of mammary preneoplasia and cancer progression.
aromatase; estrogen; receptor; breast cancer; mammary; hyperplasia
Experimental and population-based evidence has been steadily accumulating that steroid hormones are fundamentally involved in the biology of the lung. Both estrogen and progesterone receptors are present in normal and malignant lung tissue, and the reproductive hormones that bind these receptors have a role in lung development, lung inflammation, and lung cancer. The estrogen receptor β (ERβ) was discovered in the 1990's as a novel form of ER that is transcribed from a gene distinct from ERα, the receptor previously isolated from breast tissue. Interestingly, ERβ is the predominate ER expressed in normal and malignant lung tissue, while inflammatory cells that infiltrate the lung are known to express both ERα and ERβ. Although there is evidence from animal models for the preferential effects of ERβ in the lungs of females, human lung tumors from males often contain comparable numbers of ERβ-positive cells and male-derived lung cancer cell lines respond to estrogens. Lung tumors from both males and females also express CYP19 (aromatase), the rate-limiting enzyme in estrogen synthesis that converts testosterone to estrone and β-estradiol. Thus, testosterone acts as a precursor for local estrogen production within lung tumors, independent of reproductive organs. This review discusses the recent literature findings concerning the biology of the ERs, aromatase, and the progesterone receptor (PR) in lung cancer and highlights the ongoing clinical trials and future therapeutic implications of these findings.
Estrogen receptor (ER) signaling and its interaction with epidermal growth factor receptor (EGFR) is a potential therapeutic target in non-small cell lung cancer (NSCLC). To explore cross-communication between ER and EGFR, we have correlated ER pathway gene and protein expression profiles and examined effects of antiestrogens with or without EGFR inhibitors in preclinical models of human NSCLC.
We evaluated 54 NSCLC cell lines for growth inhibition with EGFR inhibitors, antiestrogen treatment or the combination. Each line was evaluated for baseline ER pathway protein expression. The majority were also evaluated for baseline ER pathway gene expression. Human NSCLC xenografts were evaluated for effects of inhibition of each pathway either individually or in combination.
The specific antiestrogen fulvestrant has modest single agent activity in vitro, but in many lines fulvestrant adds to effects of EGFR inhibitors, including synergy in the EGFR mutant, erlotinib-resistant H1975 line. ERα, ERβ, progesterone receptor (PR)-A, PR-B and aromatase proteins are expressed in all lines to varying degrees, with trends towards lower aromatase in more sensitive cell lines. Sensitivity to fulvestrant correlates with greater baseline ERα gene expression. Tumor stability is achieved in human tumor xenografts with either fulvestrant or EGFR inhibitors, but tumors regress significantly when both pathways are inhibited.
These data provide a rationale for further investigation of the antitumor activity of combined therapy with antiestrogen and anti-EGFR agents in the clinic. Future work should also evaluate dual ER and EGFR inhibition in the setting of secondary resistance to EGFR inhibition.
epidermal growth factor receptor; estrogen; estrogen receptor; lung cancer; fulvestrant
Sex steroid action is critical to form sexually dimorphic nuclei, although it is not fully understood. We previously reported that masculinization of the principal nucleus of the bed nucleus of the stria terminalis (BNSTp), which is larger and has more neurons in males than in females, involves aromatized testosterone that acts via estrogen receptor-α (ERα), but not estrogen receptor-β (ERβ). Here, we examined sex steroid action on the formation of the anteroventral periventricular nucleus (AVPV) that is larger and has more neurons in females. Morphometrical analysis of transgenic mice lacking aromatase, ERα, or ERβ genes revealed that the volume and neuron number of the male AVPV were significantly increased by deletion of aromatase and ERα genes, but not the ERβ gene. We further examined the AVPV and BNSTp of androgen receptor knockout (ARKO) mice. The volume and neuron number of the male BNSTp were smaller in ARKO mice than those in wild-type mice, while no significant effect of ARKO was found on the AVPV and female BNSTp. We also examined aromatase, ERα, and AR mRNA levels in the AVPV and BNSTp of wild-type and ARKO mice on embryonic day (ED) 18 and postnatal day (PD) 4. AR mRNA in the BNSTp and AVPV of wild-type mice was not expressed on ED18 and emerged on PD4. In the AVPV, the aromatase mRNA level was higher on ED18, although the ERα mRNA level was higher on PD4 without any effect of AR gene deletion. Aromatase and ERα mRNA levels in the male BNSTp were significantly increased on PD4 by AR gene deletion. These results suggest that estradiol signaling via ERα during the perinatal period and testosterone signaling via AR during the postnatal period are required for masculinization of the BNSTp, whereas the former is sufficient to defeminize the AVPV.
A recent epidemiological study demonstrated a reduced risk of lung cancer mortality in breast cancer patients using antiestrogens. These and other data implicate a role for estrogens in lung cancer, particularly nonsmall cell lung cancer (NSCLC). Approximately 61% of human NSCLC tumors express nuclear estrogen receptor β (ERβ); however, the role of ERβ and estrogens in NSCLC is likely to be multifactorial. Here we tested the hypothesis that proteins interacting with ERβ in human lung adenocarcinoma cells that respond proliferatively to estradiol (E2) are distinct from those in non-E2-responsive cells.
FLAG affinity purification of FLAG-ERβ-interacting proteins was used to isolate ERβ-interacting proteins in whole cell extracts from E2 proliferative H1793 and non-E2-proliferative A549 lung adenocarcinoma cell lines. Following trypsin digestion, proteins were identified using liquid chromatography electrospray ionization tandem mass spectrometry (LC-MS/MS). Proteomic data were analyzed using Ingenuity Pathway Analysis. Select results were confirmed by coimmunoprecipitation.
LC-MS/MS identified 27 non-redundant ERβ-interacting proteins. ERβ-interacting proteins included hsp70, hsp60, vimentin, histones and calmodulin. Ingenuity Pathway Analysis of the ERβ-interacting proteins revealed differences in molecular and functional networks between H1793 and A549 lung adenocarcinoma cells. Coimmunoprecipitation experiments in these and other lung adenocarcinoma cells confirmed that ERβ and EGFR interact in a gender-dependent manner and in response to E2 or EGF. BRCA1 interacted with ERβ in A549 cell lines and in human lung adenocarcinoma tumors, but not normal lung tissue.
Our results identify specific differences in ERβ-interacting proteins in lung adenocarcinoma cells corresponding to ligand-dependent differences in estrogenic responses.
Increasing evidence shows that estrogens are involved in lung cancer proliferation and progression, and most human lung tumors express estrogen receptor β (ERβ) as well as aromatase. To determine if the aromatase inhibitor anastrozole prevents development of lung tumors induced by a tobacco carcinogen, alone or in combination with the ER antagonist fulvestrant, ovariectomized female mice received treatments with the tobacco carcinogen 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone (NNK) along with daily supplements of androstenedione, the substrate for aromatase. Placebo, anastrozole and/or fulvestrant were administered in both an initiation and a promotion protocol of lung tumorigenesis. The combination of fulvestrant and anastrozole given during NNK exposure resulted in significantly fewer NNK-induced lung tumors (mean = 0.5) compared with placebo (mean = 4.6, P < 0.001), fulvestrant alone (mean = 3.4, P < 0.001) or anastrozole alone (mean = 2.8, P = 0.002). A significantly lower Ki67 cell proliferation index was also observed compared with single agent and control treatment groups. Beginning antiestrogen treatment after NNK exposure, when preneoplastic lesions had already formed, also yielded maximum antitumor effects with the combination. Aromatase expression was found mainly in macrophages infiltrating preneoplastic and tumorous areas of the lungs, whereas ERβ was found in both macrophages and tumor cells. Antiestrogens, especially in combination, effectively inhibited tobacco carcinogen-induced murine lung tumorigenesis and may have application for lung cancer prevention. 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.
The incidence of papillary thyroid cancer (PTC) is markedly higher in women than men during the reproductive years. In vitro studies have suggested that estrogen may play an important role in the development and progression of PTC through estrogen receptors (ERs). This study aimed to investigate the expression patterns of the two main ER subtypes, α and β1 (wild-type ERβ), in PTC tissue and their clinical significance.
Immunohistochemical staining of thyroid tissue sections was performed to detect ER expression in female patients with PTC (n = 89) and nodular thyroid goiter (NTG; n = 30) using the Elivision™ plus two-step system. The relationships between ER subtype expression and clinicopathological/biological factors were further analyzed.
The positive percentage and expression levels of ERα were significantly higher in female PTC patients of reproductive age (18–45 years old; n = 50) than age-matched female NTG patients (n = 30), while ERβ1 exhibited the opposite pattern. There was no difference in ERα or ERβ1 expression between female PTC patients of reproductive age and those of advanced reproductive age (>45 years old; n = 39). In the female PTC patients of reproductive age, ERα expression level was positively correlated with that of Ki-67, while ERβ1 was negatively correlated with mutant P53. Furthermore, more patients with exclusively nuclear ERα expression had extrathyroidal extension (ETE) as compared with those with extranuclear ERα localization. VEGF expression was significantly decreased in female PTC patients of reproductive age with only nuclear ERβ1 expression when compared with those with extranuclear ERβ1 localization. In PTC patients of advanced reproductive age, neither ERα nor ERβ1 expression showed any correlation with that of Ki-67, mutant P53, VEGF, tumor size, TNM stage, ETE, or lymph node metastases.
The differential expression patterns of the two ER subtypes between PTC and NTG indicate that ERα may be a useful immunohistochemical marker for differential diagnosis of PTC. The associations of ER subtype expression with Ki-67, mutant P53, VEGF expression and ETE in female PTC patients of reproductive age suggest that estrogen-activated ERα may mediate stimulatory effects on PTC growth and progression whereas ERβ1 has some inhibitory actions.
ERα; ERβ1; Papillary thyroid cancer; Ki-67; Mutant P53; VEGF
Although renal angiomyolipoma (AML) occurs more commonly in females than males, the origin of this difference in incidence by sex is unknown. Therefore, we investigated the expression of the androgen receptor (AR), estrogen receptor subtypes alpha (ERα) and beta (ERβ), progesterone receptor, and the enzyme aromatase in renal AML.
We evaluated specimens from 110 patients who had undergone resection of a renal AML, including 90 women and 20 men. Immunohistochemistry was performed using monoclonal antibodies on paraffin-embedded tissue sections. Expression was correlated with patient demographics and tumor pathologic features.
ERβ was expressed in 100% (106 of 106) of the AML specimens evaluated. Of the 104 specimens that could be assessed for the AR, 82 (79%) demonstrated staining. Of 110 lesions, 31 (28%), 42 (38%), and 11 (10%) expressed ERα, progesterone receptor, and aromatase, respectively. The level of ERβ expression was not associated with patient age (P = 0.92), sex (P = 0.82), a diagnosis of tuberous sclerosis (P = 0.56), or histologic subtype of AML (P = 0.94). A trend was found toward increased AR expression in men (P = 0.069) and younger patients (P = 0.052), and ERα was expressed in the AML specimens from 5 (71%) of 7 patients with tuberous sclerosis compared with 26 (25%) of 103 without tuberous sclerosis (P = 0.018). Both AR and ERα expression were more common in the triphasic subtype of AML than in the lipomatous tumors (P = 0.046 for both).
The results of our study have shown that ERβ expression is ubiquitous in renal AML, and the AR is found in most tumors. ERα and progesterone receptor were expressed in approximately one third of cases. These data suggest a potential role for hormones in the pathogenesis and management of renal AML.