Estrogen receptor beta (ERbeta) subtype-specific ligands increase transcription, p44/p42 mitogen activated protein kinase (MAPK) activation and growth in human non-small cell lung cancer cells

Increased risk of subsequent primary lung cancer among female hormone-related cancer patients: A meta-analysis based on over four million cases

BACKGROUND

The incidence rate of lung cancer in women has significantly increased over the past decade, and previous evidence has indicated a significant relationship between the elevated levels of sex hormones and the risk of lung cancer. Therefore, we hypothesized that female hormone-related cancer (FHRC) patients, including breast, endometrial, cervical, and ovarian cancer patients, may experience a higher risk of developing subsequent lung cancer. This meta-analysis aimed to identify the risk of lung cancer among FHRC patients compared to the general population.

METHODS

The PubMed, Web of Science, EMBASE, Cochrane Library, and CNKI databases were searched up to May 11, 2022. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) were used to identify the risk of subsequent lung cancer after FHRC. Subgroup analyses based on the follow-up time and tumor type were also conducted.

RESULTS

A total of 58 retrospective cohort studies involving 4,360,723 FHRC participants were included. The pooled results demonstrated that FHRC patients had a significantly increased risk of developing subsequent primary lung cancer (SIR = 1.61, 95% CI: 1.48-1.76, P <0.001). Subgroup analysis revealed an obvious trend of increasing lung cancer risk over time (SIRs for <5 years, ≥5 years, ≥10 years, ≥20 years, and ≥30 years after FHRC: 1.32, 1.59, 1.57, 1.68, and 1.95, respectively). In addition, subgroup analysis stratified by tumor type indicated an increased risk of developing subsequent lung cancer after breast (SIR = 1.25, P <0.001), endometrial (SIR = 1.40, P = 0.019), cervical (SIR = 2.56, P <0.001), and ovarian cancer (SIR = 1.50, P = 0.010).

CONCLUSION

FHRC patients are more likely to develop lung cancer than the general population. Furthermore, the increased risk of subsequent primary lung cancer is more obvious with a longer survival time and is observed in all types of hormone-related cancer.

REGISTRATION

International Platform of Registered Systematic Review and Meta-analysis Protocols: No. INPLASY202270044; https://inplasy.com/.

Estrogen Signals through ERβ in Breast Cancer; What We Have Learned since the Discovery of the Receptor

Estrogen receptor (ER) β (ERβ) is the second ER subtype that mediates the effects of estrogen in target tissues along with ERα that represents a validated biomarker and target for endocrine therapy in breast cancer. ERα was the only known ER subtype until 1996 when the discovery of ERβ opened a new chapter in endocrinology and prompted a thorough reevaluation of the estrogen signaling paradigm. Unlike the oncogenic ERα, ERβ has been proposed to function as a tumor suppressor in breast cancer, and extensive research is underway to uncover the full spectrum of ERβ activities and elucidate its mechanism of action. Recent studies have relied on new transgenic models to capture effects in normal and malignant breast that were not previously detected. They have also benefited from the development of highly specific synthetic ligands that are used to demonstrate distinct mechanisms of gene regulation in cancer. As a result, significant new information about the biology and clinical importance of ERβ is now available, which is the focus of discussion in the present article.

NRIP1 regulates cell proliferation in lung adenocarcinoma cells

Nuclear receptor interacting protein 1 (NRIP1) is a transcription cofactor that regulates the activity of nuclear receptors and transcription factors. Functional expression of NRIP1 has been identified in multiple cancers. However, the expression and function of NRIP1 in lung adenocarcinoma have remained unclear. Thus, we aimed to clarify the NRIP1 expression and its functions in lung adenocarcinoma cells. NRIP1 and Ki-67 were immunostained in the tissue microarray section consisting of 64 lung adenocarcinoma cases, and the association of NRIP1 immunoreactivity with clinical phenotypes was examined. Survival analysis was performed in lung adenocarcinoma data from The Cancer Genome Atlas (TCGA). Human A549 lung adenocarcinoma cell line with an NRIP1-silencing technique was used in vitro study. Forty-three of 64 cases were immunostained with NRIP1. Ki-67-positive cases were more frequent in NRIP1-positive cases as opposed to NRIP1-negative cases. Higher NRIP1 mRNA expression was associated with poor prognosis in the TCGA lung adenocarcinoma data. NRIP1 was mainly located in the nucleus of A549 cells. NRIP1 silencing significantly reduced the number of living cells, suppressed cell proliferation, and induced apoptosis. These results suggest that NRIP1 participates in the progression and development of lung adenocarcinoma. Targeting NRIP1 may be a possible therapeutic strategy against lung adenocarcinoma.

Role of sex and sex hormones in PD-L1 expression in NSCLC: clinical and therapeutic implications

Currently, immunotherapy based on PD-1/PD-L1 pathway blockade has improved survival of non-small cell lung cancer (NSCLC) patients. However, differential responses have been observed by sex, where men appear to respond better than women. Additionally, adverse effects of immunotherapy are mainly observed in women. Studies in some types of hormone-dependent cancer have revealed a role of sex hormones in anti-tumor response, tumor microenvironment and immune evasion. Estrogens mainly promote immune tolerance regulating T-cell function and modifying tumor microenvironment, while androgens attenuate anti-tumor immune responses. The precise mechanism by which sex and sex hormones may modulate immune response to tumor, modify PD-L1 expression in cancer cells and promote immune escape in NSCLC is still unclear, but current data show how sexual differences affect immune therapy response and prognosis. This review provides update information regarding anti-PD-1/PD-L immunotherapeutic efficacy in NSCLC by sex, analyzing potential roles for sex hormones on PD-L1 expression, and discussing a plausible of sex and sex hormones as predictive response factors to immunotherapy.

ERβ overexpression may not be a direct prognostic factor in patients with NSCLC: A meta-analysis

BACKGROUND

Overall survival of non-small cell lung cancer (NSCLC) patients remains disappointingly low. The estrogen receptor (ER) was considered a promising therapeutic target for NSCLC. Numerous studies have linked expression of ERβ to lung cancer outcome. However, results are conflicting regarding the association of ERβ with surviving lung cancer.

METHOD

The aim of this meta-analysis was to evaluate the prognostic aspect of ERβ expression on survival among NSCLC patients. We performed a final analysis of prognostic value of overexpression ERβ on 3500 patients from 18 evaluable studies (from January 1, 2000 to May 1, 2021). The reference category is specified as low ERβ expression levels. Summarized hazard ratios were calculated.

RESULTS

Our study showed that the pooled hazard ratios of ERβ overexpression for overall survival in NSCLC was 0.81 (95% confidence interval (CI): 0.64-1.02, P = 0.07) by univariate analysis and 1.06 (95% CI: 0.83-1.36, P = 0.63) by multivariate analysis. Pooled hazard ratio by univariate analysis in Asian studies was 0.73 (95%CI: 0.59-0.89, P = 0.002). Pooled hazard ratio by univariate analysis was 0.75 (95% CI: 0.61-0.93, P = 0.009) from seven studies reported for nuclear ERβ. No significant results were found in subgroups by multivariate analysis. No significant results were found in studies outside Asia or in studies reported for cytoplasmic ERβ.

CONCLUSION

Our results suggested that expression of ERβ might not be a direct prognostic factor for NSCLC patients. More detailed prospective studies are needed to identify direct prognostic factors in these patients.

Association of MLH1-93G>A polymorphisms toward lung cancer susceptibility and its association with clinical outcome in North Indian patients treated with platinum-based chemotherapy

Background

Lung cancer is one of the most prevalent and main causes of malignancy-related deaths worldwide, especially in developed countries. Epidemiological studies have demonstrated that individuals having alterations in a particular gene may have a high risk of developing certain types of cancer.

Materials and Methods

In the present study, 500 Indian lung cancer patients and 500 healthy controls were enrolled. Polymerase chain reaction-restriction fragment length polymorphism method was used to identify the genotype of enrolled individuals and MedCalc statistical package was used for carrying out statistical analysis.

Results

In this study, we found a reduced risk of developing adenocarcinoma in patients harboring variant (P = 0.0007) and combined type genotype (P = 0.008), whereas an increased risk for small-cell lung carcinoma (SCLC) development for those subject harboring GA genotypes (P = 0.03) was also observed. Further, heterozygous type and combined type genotype of heavy smokers for MLH1 polymorphism reported a 2-fold (P = 0.001) and 1.8-fold increased risk toward lung cancer development, respectively (P = 0.007). In case of females, the subjects harboring a variant allele have a significantly reduced risk for lung cancer development (P = 0.0001). For MLH1 polymorphism, reduced risk of developing tumor to T3 or T4 stage was observed (P = 0.04). Moreover, this is the first study reporting overall survival (OS) association for north Indian lung cancer patients with platinum-based doublet chemotherapy; for docetaxel, a three-fold increase in hazard ratio and corresponding low median standard survival time (8.4 months) for mutant and combined type genotype (P = 0.04) was observed.

Conclusions

These results suggest that MLH1-93G>A polymorphism is involved in modulating the risk toward lung cancer. Our study also concluded a negative association of OS in patients undergoing carboplatin/cisplatin and docetaxel chemotherapy.

A Role for ER-Beta in the Effects of Low-Density Lipoprotein Cholesterol and 27-Hydroxycholesterol on Breast Cancer Progression: Involvement of the IGF Signalling Pathway?

Cholesterol-in particular, high levels of low-density lipoprotein (LDL) and its metabolite, 27-hydroxycholesterol (27-OHC)-is correlated with increases in the risks of breast cancer and obesity. Although the high expression of LDL/27-OHC has been reported in breast cancer, its effects and mechanism of action remain to be fully elucidated. In this study, we found that the effects of LDL on cell proliferation were mediated by the activation of the cytochrome P450 enzyme, sterol 27 hydroxylase, and cholesterol 27-hydroxylase (CYP27A1) in both ER-α-positive and ER-α-negative breast cancer cells. We found that treatment with 27-OHC only increased cell growth in oestrogen receptor-α (ER-α)-positive breast cancer cells in an ER-α-dependent manner, but, interestingly, the effects of 27-OHC on cell migration and invasion were independent of ER-α. Using ER-α-negative MDA-MB-231 cells, we found that 27-OHC similarly promoted cell invasion and migration, and this was mediated by oestrogen receptor β (ER-β). These results suggest that 27-OHC promotes breast cancer cell proliferation in ER-α-positive breast cancer cells via ER-α, but migration and invasion are mediated via ER-β in ER-α positive and negative cell lines. The addition of LDL/27OHC increased the production of IGF-I and the abundance of IGF-IR in TNBC. We further found that modulating ER-β using an agonist or antagonist increased or decreased, respectively, levels of the IGF-I and EGF receptors in TNBC. The inhibition of the insulin-like growth factor receptor blocked the effects of cholesterol on cell growth and the migration of TNBC. Using TCGA and METABRIC microarray expression data from invasive breast cancer carcinomas, we also observed that higher levels of ER-beta were associated with higher levels of IGF-IR. Thus, this study shows novel evidence that ER-β is central to the effects of LDL/27OHC on invasion, migration, and the IGF and EGF axes. Our data suggest that targeting ER-β in TNBC could be an alternative approach for downregulating IGF/EGF signalling and controlling the impact of LDL in breast cancer patients.

Non-genomic signaling of steroid receptors in cancer

Steroid receptors (SRs) are members of the nuclear receptor family, which are ligand-activated transcription factors. SRs regulate many physiological functions including development and reproduction, though they can also be involved in several pathologies, especially cancer. Highly controlled cellular responses to steroids involve transcriptional regulation (genomic activity) combined with direct activation of signaling cascades (non-genomic activity). Non-genomic signaling has been extensively studied in cancer, mainly in breast cancer for ER and PR, and prostate cancer for AR. Even though most of the studies have been conducted in cells, some of them have been confirmed in vivo, highlighting the relevance of this pathway in cancer. This review provides an overview of the current and emerging knowledge on non-genomic signaling with a focus on breast and prostate cancers and its clinical relevance. A thorough understanding of ER, PR, AR and GR non-genomic pathways may open new perspectives for the development of therapeutic strategies.

Estrogen Receptor ß in Cancer: To ß(e) or not to ß(e)?

Estrogen receptors (ERs) are known to play an important role in the proper development of estrogen-sensitive organs, as well as in the development and progression of various types of cancer. ERα, the first ER to be discovered, has been the focus of most cancer research, especially in the context of breast cancer. However, ERβ expression also plays a significant role in cancer pathophysiology, notably its seemingly protective nature and loss of expression with oncogenesis and progression. Although ERβ exhibits antitumor activity in breast, ovarian, and prostate cancer, its expression is associated with disease progression and worse prognosis in lung cancer. The function of ERβ is complicated by the presence of multiple isoforms and single nucleotide polymorphisms, in addition to tissue-specific functions. This mini-review explores current literature on ERβ and its mechanism of action and clinical implications in breast, ovarian, prostate, and lung cancer.

Investigation of Combination Treatment With an Aromatase Inhibitor Exemestane and Carboplatin-Based Therapy for Postmenopausal Women With Advanced NSCLC

Introduction

Estrogen receptors (ER) (ERα, ERβ) and aromatase (key enzyme for estrogen synthesis) are expressed in most human NSCLCs. High intratumoral estrogen levels and elevated aromatase expression in NSCLC predict poor outcome. This open-label, phase 1b, single-center study evaluated the safety and tolerability of escalating doses of the aromatase inhibitor, exemestane, in combination with carboplatin and pemetrexed in postmenopausal women with stage IV nonsquamous NSCLC.

Methods

Patients received exemestane (starting 1-wk before chemotherapy) at 25 mg orally (PO) daily (cohort 1) or 50 mg PO daily (cohort 2) combined with carboplatin (area under the curve 6 mg × min/mL) and pemetrexed (500 mg/m²) intravenously every 3 weeks for four cycles. Thereafter, patients were eligible for continued therapy with exemestane and pemetrexed or pemetrexed alone.

Results

A total of 10 patients consented for therapy, and two patients failed in the screening. Four patients completed the therapy in cohort 1 and four patients in cohort 2. The median number of cycles administered was 15 (range: 1-54). Maximum tolerated dose was exemestane 50 mg PO daily with combination chemotherapy. Intention-to-treat analysis revealed an objective response rate (ORR) of 62.5% (five of eight patients with partial response) and a clinical benefit rate of 87.5% (seven of eight patients with either stable disease or partial response). ORR was associated with aromatase expression (p = 0.02). Circulating estrogen levels decreased with exemestane use, and quality of life measurements did not significantly change during the treatment. There were no adverse events.

Conclusions

The combination of carboplatin, pemetrexed, and exemestane in postmenopausal women with metastatic NSCLC is safe and well tolerated. Biomarker studies revealed that ORR correlates with tumor aromatase expression. These findings support future clinical trials to confirm the antitumor efficacy with this combination therapy.

Upregulation of estrogen receptor beta protein but not mRNA predicts poor prognosis and may be associated with enhanced translation in non-small cell lung cancer: a systematic review and meta-analysis

Background

An increasing number of original studies suggest that estrogen receptor beta (ERβ) expression may be related to non-small cell lung cancer (NSCLC) prognosis; however, the evidence remains inconclusive and conflicting. We aimed to systematically evaluate the expression and prognostic value of ERβ in NSCLC, and to explain the inconsistency between ERβ protein and mRNA level.

Methods

PubMed, Embase, and Web of Science databases were searched for studies (published before October 6, 2020) reporting the prognostic value of ERβ protein expression in NSCLC. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS) were calculated. Transcriptome and survival data of lung adenocarcinoma patients were obtained from public databases for differential expression and survival analyses. Immunohistochemistry (IHC) was performed to examine the ERβ protein expression in 39 NSCLC patients. Western blotting and RT-qPCR were performed to analyze ERβ expression in two paired NSCLC and normal adjacent tissue samples. The effect of methyltransferase-like 13 (METTL3) on ERβ expression was investigated in a lung cancer cell line.

Results

Meta-analysis of 23 studies with a total of 3744 patients demonstrated that high protein expression of overall ERβ and cytoplasmic ERβ indicated poor OS (HR: 1.05, 95% CI: 1.00 to 1.10; HR: 1.48, 95% CI: 1.13 to 1.95) in NSCLC. For lung adenocarcinoma especially, high protein expression of both overall/cytoplasmic ERβ and nuclear ERβ suggested poor OS (HR: 1.54, 95% CI: 1.05 to 2.25; HR: 1.36, 95% CI: 1.03 to 1.80). Bioinformatics analysis indicated the expression of ERβ mRNA was not associated with the prognosis of lung adenocarcinoma. Analysis of public databases showed that ERβ mRNA is not highly expressed in tumor tissues, however, IHC results revealed that ERβ protein is highly expressed in NSCLC tissues. We validated this inconsistency in ERβ expression in paired tumors and normal adjacent tissues from patients. Moreover, METTL3 knockdown in the A549 cell line downregulated ERβ protein expression but not ERβ mRNA expression.

Conclusions

Our study elucidated the inconsistency between ERβ protein and mRNA expression levels and their prognostic values. The results indicated that METTL3-driven enhanced translation in NSCLC may cause this inconsistency.

The smoking estrogens - a potential synergy between estradiol and benzo(a)pyrene

According to recent statistics, Lung Cancer (LC) is one of the most frequently diagnosed tumor types, representing nearly 12% of all global cancer cases. Moreover, in recent years, an increased mortality rate and incidence of this cancer were observed, especially among nonsmokers. Lung cancer patients are often characterized by poor prognosis and low survival rates, which encourages the scientific community to investigate the biochemical and molecular processes leading to the development of this malignancy. Furthermore, the mechanisms of LC formation and progression are not yet fully elucidated due to their high complexity, as well as a multitude of environmental, genetic, and molecular factors involved. Even though LC's association with exposure to cigarette smoke is indisputable, current research provides evidence that the development of this cancer can also be affected by the presence of estrogens and their interaction with several tobacco smoke components. Hence, the main goal of this brief review was to investigate reports of a possible synergy between 17β estradiol (E2), the most biologically active estrogen, and benzo(a)pyrene (BaP), a strongly carcinogenic compound produced as a result of incomplete tobacco combustion. The literature sources demonstrate a possible carcinogenic synergy between estrogens, especially E2, and BaP, a toxic tobacco smoke component. Therefeore, the combined effect of disturbed estrogen production in cancer cells, as well as the molecular influence exerted by BaP, could explain the increased aggressiveness and rate of LC development. Summarizing, the synergistic effect of these risk factors is an interesting area of further research.

Sex Hormones and Lung Inflammation

Inflammation is a characteristic marker in numerous lung disorders. Several immune cells, such as macrophages, dendritic cells, eosinophils, as well as T and B lymphocytes, synthetize and release cytokines involved in the inflammatory process. Gender differences in the incidence and severity of inflammatory lung ailments including asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), lung cancer (LC), and infectious related illnesses have been reported. Moreover, the effects of sex hormones on both androgens and estrogens, such as testosterone (TES) and 17β-estradiol (E2), driving characteristic inflammatory patterns in those lung inflammatory diseases have been investigated. In general, androgens seem to display anti-inflammatory actions, whereas estrogens produce pro-inflammatory effects. For instance, androgens regulate negatively inflammation in asthma by targeting type 2 innate lymphoid cells (ILC2s) and T-helper (Th)-2 cells to attenuate interleukin (IL)-17A-mediated responses and leukotriene (LT) biosynthesis pathway. Estrogens may promote neutrophilic inflammation in subjects with asthma and COPD. Moreover, the activation of estrogen receptors might induce tumorigenesis. In this chapter, we summarize the most recent advances in the functional roles and associated signaling pathways of inflammatory cellular responses in asthma, COPD, PF, LC, and newly occurring COVID-19 disease. We also meticulously deliberate the influence of sex steroids on the development and progress of these common and severe lung diseases.

An Overview of Lung Cancer in Women and the Impact of Estrogen in Lung Carcinogenesis and Lung Cancer Treatment

Lung cancer incidence and mortality have significantly increased in women worldwide. Lung adenocarcinoma is the most common form of lung cancer globally. This type of lung cancer shows differences by sex, including the mutational burden, behavior, clinical characteristics, and response to treatment. The effect of sex on lung cancer patients' survival is still controversial; however, lung adenocarcinoma is considered a different disease in women and men. Moreover, lung adenocarcinoma is strongly influenced by estrogen and is also different depending on the hormonal status of the patient. Young pre-menopausal women have been explored as an independent group. They presented in more advanced stages at diagnosis, exhibited more aggressive tumors, and showed poor survival compared to men and post-menopausal women, supporting the role of sex hormones in this pathology. Several reports indicate the estrogen's role in lung carcinogenesis and tumor progression. Thus, there are currently some clinical trials testing the efficacy of antihormonal therapy in lung cancer treatment. This mini review shows the updated data about lung cancer in women, its characteristics, the etiological factors that influence carcinogenesis, and the critical role of estrogen in lung cancer and treatment.

Lung cancer screening strategy for non-high-risk individuals: a narrative review

Lung cancer is the deadliest malignancy worldwide, accounting for almost 20% of all cancer deaths. Clinical trials, such as NLST and NELSON, have proved the survival benefit of lung cancer screening using low-dose computed tomography (LDCT), and most of the lung cancer screening guidelines recommended annual lung cancer screening by LDCT for high-risk individuals. However, a relatively high proportion of lung cancer patients do not have risk factors, and it is questionable whether non-high-risk individuals should receive LDCT screening. In this review, we reviewed risk factors of lung cancer and summarized the benefits and potential harms of LDCT screening. After clarifying the differences between China and western countries in lung cancer screening, we recommended that non-high-risk individuals should receive LDCT screening with an interval of five to ten years. To better balance benefits and harms from LDCT screening, we also proposed a flexible screening strategy using LDCT based on lung cancer risk. Hopefully, it may help reduce unnecessary radiation exposure from CT scans while decreasing mortality of lung cancer.

An examination of two dichotomies: Women with lung cancer and living with lung cancer as a chronic disease

Lung cancer remains the leading cause of cancer death globally, yet with many recent advances in the diagnosis and treatment of lung cancer, the face of the disease is shifting. Historically, lung cancer is often thought of as a predominantly male disease with more than twice as many men as women being diagnosed worldwide-mostly due to the influence of smoking as the leading risk factor. However, lung cancer is also the second leading cause of cancer death in women and there is a growing population of young women who have never smoked and are being diagnosed. The past decade has seen groundbreaking innovations in both the early detection and treatment of lung cancer. In this new era, survival rates are beginning to increase and many of those diagnosed are finding themselves in a new situation-living long term with a deadly cancer. Here, we review pertinent aspects of women and lung cancer as well as the concept of living with lung cancer as a chronic disease to give a new perspective on the changing face of lung cancer treatment and care.

Estrogen Receptor Beta (ERβ): A Ligand Activated Tumor Suppressor

Estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) belong to a superfamily of nuclear receptors called steroid hormone receptors, which, upon binding ligand, dimerize and translocate to the nucleus where they activate or repress the transcription of a large number of genes, thus modulating critical physiologic processes. ERβ has multiple isoforms that show differing association with prognosis. Expression levels of the full length ERβ1 isoform are often lower in aggressive cancers as compared to normal tissue. High ERβ1 expression is associated with improved overall survival in women with breast cancer. The promise of ERβ activation, as a potential targeted therapy, is based on concurrent activation of multiple tumor suppressor pathways with few side effects compared to chemotherapy. Thus, ERβ is a nuclear receptor with broad-spectrum tumor suppressor activity, which could serve as a potential treatment target in a variety of human cancers including breast cancer. Further development of highly selective agonists that lack ERα agonist activity, will be necessary to fully harness the potential of ERβ.

Altered expression of 17‑β‑hydroxysteroid dehydrogenase type 2 and its prognostic significance in non‑small cell lung cancer

Numerous studies have reported that oestrogens may contribute to the development of non small cell lung cancer (NSCLC). Although different steroidogenic enzymes have been detected in the lung, the precise mechanism leading to an exaggerated accumulation of active oestrogens in NSCLC remains unexplained. 17 β Hydroxysteroid dehydro genase type 2 (HSD17B2) is an enzyme involved in oestrogen and androgen inactivation by converting 17 β oestradiol into oestrone, and testosterone into 4 androstenedione. Therefore, the enzyme serves an important role in regulation of the intra cellular availability of active sex steroids. This study aimed to determine the expression levels of HSD17B2 in lung cancer (LC) and adjacent histopathologically unchanged tissues obtained from 161 patients with NSCLC, and to analyse the association of HSD17B2 with clinicopathological features. For that purpose, reverse transcription quantitative PCR, western blotting and immunohistochemistry were conducted. The results revealed that the mRNA and protein expression levels of HSD17B2 were significantly decreased in LC tissues compared with matched controls (P<10 ⁶). Conversely, strong cytoplasmic staining of HSD17B2 was detected in the unchanged respiratory epithelium and in glandular cells. Notably, a strong association was detected between reduced HSD17B2 expression and advanced tumour stage, grade and size. Furthermore, it was revealed that HSD17B2 may have potential prognostic significance in NSCLC. A log-rank test revealed the benefit of high HSD17B2 protein expression for the overall survival (OS) of patients (P=0.0017), and multivariate analysis confirmed this finding (hazard ratio=0.21; 95% confidence interval=0.07-0.63; P=0.0043). Stratified analysis in the Kaplan Meier Plotter database indicated that patients with higher HSD17B2 expression presented better OS and post-progression survival. This beneficial effect was particularly evident in patients with adenocarcinoma and during the early stages of NSCLC. Decreased expression of HSD17B2 appears to be a frequent feature in NSCLC. Retrospective analysis suggests that the HSD17B2 mRNA and protein status might be independent prognostic factors in NSCLC and should be further investigated.

Influence of Estrogen on the NSCLC Microenvironment: A Comprehensive Picture and Clinical Implications

Lung cancer mortality represents the leading cause of cancer related deaths in the United States and worldwide. Almost half of these deaths occur in female patients, making lung cancer the most common cause of cancer mortality in women with a higher annual mortality rate than breast, uterine, and ovarian cancers combined. The distinct epidemiological, histological and biological presentation of non-small cell lung cancer (NSCLC) in women combined with extensive preclinical data have demonstrated that the female sex hormone β-estradiol (E2) plays an important role in NSCLC tumorigenesis, prognosis, and treatment response. Estrogen receptors are widely expressed on stromal and immune cells, and estrogen-linked signaling pathways are known to be involved in regulating the response of both the innate and adaptive immune system. Immune evasion has been recognized as a “hallmark” of cancer and immunotherapy has re-defined standard of care treatment for NSCLC. Despite these advancements, the low response rates observed in patients treated with immune checkpoint inhibitors has led to a search for mediators of immunosuppression and ways to augment the action of these agents. We focus on emerging data describing sex differences that modulate immunotherapy efficacy in NSCLC, immunosuppressive properties of E2 that lead to a pro-tumor microenvironment (TME), and the translational potential of altering the immune microenvironment by targeting the estrogen signaling pathway. E2-induced modulation affects multiple cell types within the TME, including cancer-associated fibroblasts, tumor infiltrating myeloid cells, and tumor infiltrating lymphocytes, all of which interplay with lung tumor cells via E2 and estrogen receptor engagement, ultimately shaping the TME that may, in part, be responsible for the sex-based disparities observed in NSCLC. An improved understanding of the role of the estrogen pathway in NSCLC anti-cancer immunity may lead to novel therapeutic approaches for altering the TME to improve the efficacy of immunotherapy agents.

Expression of estrogen receptor beta and overall survival in non-small cell lung cancer patients: Protocol for a systematic review and meta-analysis of cohort studies

BACKGROUND

Lung cancer is the leading cause of cancer-related deaths among males and the second leading cause among females worldwide. Numerous studies have linked estrogen status to lung cancer outcome. However, there are studies with conflicting results about the effect of ERβ on survival of lung cancer. The aim of this meta-analysis is to evaluate the prognostic impact of estrogen receptor beta expression on survival among NSCLC patients.

METHODS

We will search 15 electronic databases, including PubMed, Web of Science, EMBASE, Cochrane Library, and CNKI from inception to June 1, 2019. We will include all cohort studies comparing overall survival of NSCLC patients with high or low estrogen receptor beta expression. The database searches will be supplemented by searching through citations and references. Two reviewers will independently screen search results to identify eligible articles, complete data collection, and conduct quality assessment. All disagreements will be resolved by an independent third reviewer. Methodological quality of the included studies will be assessed using the Newcastle- Ottawa scale. Discrepancies will be resolved by consensus or by consulting a third author. Meta-analyses will be performed, and findings will be reported according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) and the meta-analysis of observational studies in epidemiology (MOOSE) guidelines.

RESULTS

The results will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This review will provide a comprehensive evaluation of the evidence on the prognostic impact of ERβ expression among NSCLC patients and will help clinicians find potential treatments based on estrogen signaling.

The estrogen pathway as a modulator of response to immunotherapy

Lung cancer is the leading cause of cancer deaths worldwide, with a 5-year survival rate of about 18%. Thus, there is a great need for novel therapeutic approaches to treat non-small-cell lung cancer (NSCLC). Immune checkpoint inhibitors (ICIs) have improved outcomes for a subset of patients, especially those with high programmed death-ligand 1 expression and/or high tumor mutational burden, but have failed in the majority of patients. Increasing evidence suggests that the estrogen signaling pathway may be a therapeutic target in metastatic NSCLC and that the estrogen pathway may play a role in sex-based responses to ICIs. This report will review the epidemiologic, preclinical and clinical data on the estrogen pathway in NSCLC, its implications in sex-based responses to ICIs and the potential use of antiestrogen therapy in combination with ICIs.

Estrogen receptor-alpha isoforms are the main estrogen receptors expressed in non-small cell lung carcinoma

The expression profile of estrogen receptors (ER) in Non-Small Cell Lung Carcinoma (NSCLC) remains contradictory. Here we investigated protein and transcriptome expression of ERα wild type and variants. Tissue Micro-Arrays of 200 cases of NSCLC (paired tumor/non-tumor) were assayed by immunohistochemistry using a panel of ERα antibodies targeting different epitopes (HC20, 6F11, 1D5, ERα36 and ERα17p). ERβ epitopes were also examined for comparison. In parallel we conducted a probe-set mapping (Affymetrix HGU133 plus 2 chip) meta-analysis of 12 NSCLC tumor public transcriptomic studies (1418 cases) and 39 NSCLC cell lines. Finally, we have investigated early transcriptional effects of 17β-estradiol, 17β-estradiol-BSA, tamoxifen and their combination in two NSCLC cell lines (A549, H520). ERα transcript and protein detection in NSCLC specimens and cell lines suggests that extranuclear ERα variants, like ERα36, prevail, while wild-type ERα66 is minimally expressed. In non-tumor lung, the wild-type ERα66 is quasi-absent. The combined evaluation of ERα isoform staining intensity and subcellular localization with sex, can discriminate NSCLC subtypes and normal lung. Overall ERα transcription decreases in NSCLC. ERα expression is sex-related in non-tumor tissue, but in NSCLC it is exclusively correlating with tumor histologic subtype. ERα isoform protein expression is higher than ERβ. ERα isoforms are functional and display specific early transcriptional effects following steroid treatment. In conclusion, our data show a wide extranuclear ERα-variant expression in normal lung and NSCLC that is not reported by routine pathology ER evaluation criteria, limited in the nuclear wild type receptor.

Lymph/angiogenesis contributes to sex differences in lung cancer through oestrogen receptor alpha signalling

Oestrogen signalling pathways are emerging targets for lung cancer therapy. Unravelling the contribution of oestrogens in lung cancer development is a pre-requisite to support the development of sex-based treatments and identify patients who could potentially benefit from anti-oestrogen treatments. In this study, we highlight the contribution of lymphatic and blood endothelia in the sex-dependent modulation of lung cancer. The orthotopic graft of syngeneic lung cancer cells into immunocompetent mice showed that lung tumours grow faster in female mice than in males. Moreover, oestradiol (E2) promoted tumour development, increased lymph/angiogenesis and VEGFA and bFGF levels in lung tumours of females through an oestrogen receptor (ER) alpha-dependent pathway. Furthermore, while treatment with ERb antagonist was inefficient, ERa antagonist (MPP) and tamoxifen decreased lung tumour volumes, altered blood and lymphatic vasculature and reduced VEGFA and bFGF levels in females, but not in males. Finally, the quantification of lymphatic and blood vasculature of lung adenocarcinoma biopsies from patients aged between 35 and 55 years revealed more extensive lymphangiogenesis and angiogenesis in tumour samples issued from women than from men. In conclusion, our findings highlight an E2/ERa-dependent modulation of lymphatic and blood vascular components of lung tumour microenvironment. Our study has potential clinical implication in a personalised medicine perspective by pointing to the importance of oestrogen status or supplementation on lung cancer development that should be considered to adapt therapeutic strategies.

Androgen deprivation therapy is associated with decreased second primary lung cancer risk in the United States veterans with prostate cancer

OBJECTIVES

We investigated whether androgen deprivation therapy (ADT) in prostate cancer patients was associated with a decreased risk for second primary lung cancer in US veterans.

METHODS

Prostate cancer diagnoses in the US Veterans Affairs Cancer Registry between 1999 and 2008 were identified. Use of hormonal therapy and diagnoses of second primary lung cancer were determined from the registry. Synchronous prostate and lung cancers, defined as 2 diagnoses made within 1 year, were excluded from the analysis. Cancer-free survival was estimated using the Kaplan-Meier method and hazard ratios were estimated using Cox proportional hazard models.

RESULTS

Among the 63,141 identified patients with prostate cancer, 18,707 subjects were eligible for the study. Hormonal therapy was used in 38% of patients and the median follow-up period was 28 months. ADT use was associated with longer lung cancer-free survival in prostate cancer patients (log-rank p=0.01). After adjusting for age, race, smoking and prostate cancer stage, ADT use was associated with decreased lung cancer risk by 15, 21, and 24% after 1, 2, and 3 years, respectively.

CONCLUSIONS

ADT in prostate cancer patients may be associated with decreased second primary lung cancer risk among US veterans.

Oestrogen receptor β5 and epidermal growth factor receptor synergistically promote lung cancer progression

Oestrogen receptor beta (ERβ) and epidermal growth factor receptor (EGFR) pathway can synergistically promote the proliferation, invasion, and metastasis of non-small-cell lung cancer (NSCLC) cells. ERβ has five subtypes, and the selective splicing of exon 8 in ERβ5 transcription translational phase makes its biological function different from other subtypes. The following study investigates whether ERβ5 interacts with EGFR pathway in lung cancer. Briefly, we found that the overexpression of ERβ5 and EGFR is associated with poor prognosis and decreased overall survival in NSCLC patients. Furthermore, the effects of ERβ5 and EGFR on cell biological behaviour were investigated in vitro. These results indicated that the combination of ERβ5 and EGF induces cell proliferation and invasion, while the combination of ERβ5 and Gefitinib (EGFR inhibitors, Gef) induces cell apoptosis and promotes cell mitosis in A549 cell line. In addition, the combination of ERβ5 and EGF increases the expression of ERβ5, EGFR, and p-ERK1/2 in lung cancer cells. To sum up, the obtained results suggest that ERβ5 and EGFR synergistically promote the progression of lung cancer by activating MEK/ERK signalling pathway, which provides a theoretical basis for more accurate combined targeted therapy.

Cytoplasmic expression of estrogen receptor β may predict poor outcome of EGFR-TKI therapy in metastatic lung adenocarcinoma

There is growing evidence that estrogen receptors (ER) are expressed in lung cancer cells, and are able to interact with the epidermal growth factor receptor (EGFR) signaling pathway. However, data on the association between cytoplasmic ER expression and the response to EGFR-tyrosine kinase inhibitors (TKI) treatment are limited. The aim of the present study was to investigate the associations between ERα/ERβ expression and EGFR mutational status and response to TKI treatment in metastatic lung adenocarcinoma. A retrospective study of 126 consecutive patients with lung adenocarcinoma who were diagnosed with stage IV disease and had received EGFR-TKI treatment was conducted. ER expression was detected by immunohistochemistry. EGFR and GTPase KRas (KRAS) mutational statuses were evaluated by denaturing high performance liquid chromatography and PCR-restriction fragment length polymorphism, respectively. In the overall cohort of 126 lung adenocarcinoma samples analyzed, ERα expression in the nucleus of tumor cells was identified in 17 (18.9%) patients, whereas ERβ expression was identified in the nucleus (22/126, 17.5%) and cytoplasm (17/126, 13.5%). The nuclear expression of ERβ was positively associated with the degree of tumor differentiation (P=0.010). EGFR-sensitizing mutations were significantly associated with improved objective response rates (ORR), disease control rates (DCR), median progression-free survival (mPFS) and median overall survival (mOS) (P<0.001; P<0.001; P=0.003; and P=0.026, respectively). Patients with cytoplasmic ERβ expression exhibited non-significant poorer ORR, DCR, mPFS and mOS compared with patients without cytoplasmic ERβ expression (P=0.082; P=0.106; P=0.084; and P=0.119, respectively). However, the significant decrease of ORR, DCR and mPFS was observed in patients with coexisting cytoplasmic ERβ expression and EGFR-sensitizing mutations (P=0.030; P=0.009; and P=0.018, respectively) in comparison with the subgroup with EGFR sensitizing mutations but negative expression of cytoplasmic ERβ. A trend towards shorter mOS was also observed in patients with coexisting cytoplasmic ERβ expression and EGFR-sensitizing mutations (P=0.071). No KRAS mutations were identified in patients with cytoplasmic ERβ expression. Subsequent to adjusting for sex, smoking status and EGFR mutation status, the Cox repression analysis indicated that cytoplasmic expression of ERβ was a negative independent predictor for mPFS in the whole patient cohort (HR=1.870; 95% confidence interval 1.058–3.305; P=0.031). Cytoplasmic ERβ expression was negatively correlated with the efficacy of EGFR-TKI treatment for metastatic lung adenocarcinoma, particularly for patients with coexisting cytoplasmic ERβ expression and EGFR-sensitizing mutations. Cytoplasmic ERβ may be a promising marker to predict the outcome of EGFR-TKI treatment.

Interaction between the estrogen receptor and fibroblast growth factor receptor pathways in non-small cell lung cancer

The estrogen receptor (ER) promotes non-small cell lung cancer (NSCLC) proliferation. Since fibroblast growth factors (FGFs) are known regulators of stem cell markers in ER positive breast cancer, we investigated whether a link between the ER, FGFs, and stem cell markers exists in NSCLC. In lung preneoplasias and adenomas of tobacco carcinogen exposed mice, the anti-estrogen fulvestrant and/or the aromatase inhibitor anastrozole blocked FGF2 and FGF9 secretion, and reduced expression of the stem cell markers SOX2 and nanog. Mice administered β-estradiol during carcinogen exposure showed increased FGF2, FGF9, SOX2, and Nanog expression in airway preneoplasias. In normal FGFR1 copy number NSCLC cell lines, multiple FGFR receptors were expressed and secreted several FGFs. β-estradiol caused enhanced FGF2 release, which was blocked by fulvestrant. Upon co-inhibition of ER and FGFRs using fulvestrant and the pan-FGFR inhibitor AZD4547, phosphorylation of FRS2, the FGFR docking protein, was maximally reduced, and enhanced anti-proliferative effects were observed. Combined AZD4547 and fulvestrant enhanced lung tumor xenograft growth inhibition and decreased Ki67 and stem cell marker expression. To verify a link between ERβ, the predominant ER in NSCLC, and FGFR signaling in patient tumors, mRNA analysis was performed comparing high versus low ERβ expressing tumors. The top differentially expressed genes in high ERβ tumors involved FGF signaling and human embryonic stem cell pluripotency. These results suggest interaction between the ER and FGFR pathways in NSCLC promotes a stem-like state. Combined FGFR and ER inhibition may increase the efficacy of FGFR inhibitors for NSCLC patients lacking FGFR genetic alterations.

ERβ-Mediated Alteration of circATP2B1 and miR-204-3p Signaling Promotes Invasion of Clear Cell Renal Cell Carcinoma

Early studies have indicated that estrogen receptor beta (ERβ) can influence the progression of clear cell renal cell carcinoma (ccRCC). Here, we report the mechanistic details of ERβ-mediated progression of ccRCC. ERβ increased ccRCC cell invasion via suppression of circular RNA ATP2B1 (circATP2B1) expression by binding directly to the 5' promoter region of its host gene ATPase plasma membrane Ca2⁺ transporting 1 (ATP2B1). ERβ-suppressed circATP2B1 then led to reduced miR-204-3p, which increased fibronectin 1 (FN1) expression and enhanced ccRCC cell invasion. Targeting ERβ with shRNA suppressed ccRCC metastasis in a murine model of RCC; adding circATP2B1 shRNA partly reversed this effect. Consistent with these experimental results, ccRCC patient survival data from The Cancer Genome Atlas indicated that a patient with higher ERβ and FN1 expression had worse overall survival and a patient with higher miR-204-3p expression had significantly better overall survival. Together, these results suggest that ERβ promotes ccRCC cell invasion by altering the ERβ/circATP2B1/miR-204-3p/FN1 axis and that therapeutic targeting of this newly identified pathway may better prevent ccRCC progression.Significance: These results identify an ERβ/circATP2B1/miR-204-3p/FN1 signaling axis in RCC, suggesting ERβ and circular RNA ATP2B1 as prognostic biomarkers for this disease. Cancer Res; 78(10); 2550-63. ©2018 AACR.

Decreased expression of cytochrome p450 1B1 in non-small cell lung cancer

Recent studies have associated oestrogen metabolism and cigarette smoking with their carcinogenic impact on the lungs. Compounds commonly found in tobacco smoke induce the activity of CYP1B1, the enzyme responsible for the synthesis of catecholic derivatives of oestrogens. During their redox transformations, these structures can release large amounts of reactive oxygen species or can form DNA adducts, which lead to the decomposition of genetic material. This process may illustrate the synergistic effect of oestrogenic activity and tobacco combustion on oestrogen-dependant lung cancer development. There is considerable evidence suggesting that the level of oestrogen in lung tumours is elevated. Therefore, by using reverse transcription, real-time PCR and Western Blot analysis, we evaluated the CYP1B1 status in tissues from 76 patients diagnosed with non-small cell lung cancer (NSCLC) to confirm whether potential overexpression of CYP1B1 may impact lung cancerogenesis induced by oestrogens. We found significantly lower levels of CYP1B1 transcripts (p=0.00001) and proteins (p=0.000085) in lung tumour material compared to corresponding, histopathologically unchanged tissues. We also analysed the association of CYP1B1 expression with gender, age and clinicopathological data of NSCLC patients. We observed lower amounts of CYP1B1 occurring in the middle stages of LC, regardless of gender, age or histological type of lung cancer.

Estrogen induces CXCR4 overexpression and CXCR4/CXL12 pathway activation in lung adenocarcinoma cells in vitro

PURPOSE

This study was designed to investigate whether estradiol is related to the expression of the chemokine receptor CXCR4 and its activation in lung adenocarcinoma in vitro, since lung adenocarcinomas from premenopausal women have shown high levels of CXCR4, and this expression has been associated with worse prognosis and poor survival.

METHODS

The effect of 17-β-estradiol (E2) (0.03 nM-10 nM) on CXCR4 expression was analyzed in lung adenocarcinoma cell lines (SK-LU-1, H1435, H23, A549) by immunofluorescence after 24 and 72-h poststimulation. Tamoxifen treatment was applied to corroborate the estrogenic effect. The wound-healing assay was performed to investigate whether E2 treatment increased CXCR4/CXL12 pathway activity. A549 and SK-LU-1 cells were stimulated with E2, CXCL12, and CXCL12 combined with E2. Tamoxifen and AMD3100 were applied to corroborate estrogen and chemokine pathway activation.

RESULTS

Estradiol stimulated significantly CXCR4 overexpression in all the cell lines analyzed in a dose- and a time-dependent manner. Tamoxifen treatment inhibited the CXCR4 overexpression observed in estrogen-treated groups, demonstrating that estrogen strongly influences CXCR4 expression in lung adenocarcinoma cells. Cells treated with E2, CXCL12 and E2 combined with CXCL12 exhibited significant cell migration, which was suppressed when tamoxifen and AMD3100 were present.

CONCLUSION

Overexpression of CXCR4 induced by estrogen and the activity of CXCL12/CXCR4 pathway could be a new mechanism by which this hormone supports tumor progression and metastasis. These findings may partly explain the worse prognosis observed in premenopausal women and suggest considering the role of estrogen in lung cancer for the design of more specific treatment schemes.

Risk factors of Lung Cancer in nonsmoker

Generally, the cause of lung cancer is attributed to tobacco smoking. But many of the new lung cancer cases have been reported in nonsmokers. Apart from smoking; air pollution, environmental exposure, mutations, and single-nucleotide polymorphisms are known to be associated with lung cancer. Improper diet, alcohol consumption, marijuana smoking, estrogen, infections with human papillomavirus (HPV), HIV, and Epstein-Barr virus are suggested to be linked with lung cancer but clear evidences to ascertain their relation is not available. This article provides a comprehensive review of various risk factors and the underlying molecular mechanisms responsible for increasing the incidence of lung cancer. The pathologic, histologic, and genetic differences exist with lung cancer among smokers and nonsmokers. A better understanding of the risk factors, differences in pathology and molecular features of lung cancer in smokers and nonsmokers and the mode of action of various carcinogens will facilitate the prevention and management of lung cancer.

Correlation between epidermal growth factor receptor mutations and the expression of estrogen receptor-β in advanced non-small cell lung cancer

Epidermal growth factor receptor (EGFR) mutations are more common in non-small cell lung cancer (NSCLC) and in female patients of East Asian origin. Therefore, the present study investigated the presence of EGFR mutations in advanced NSCLC, and assessed its correlation with clinicopathologic factors, including the expression of estrogen receptor-β (ER-β) and patient prognosis. The present study performed a retrospective analysis of 83 patients with stage IIIB-IV NSCLC. The expression of ER-β and p53 were examined using immunohistochemical methods. EGFR mutations were evaluated using the amplification refractory mutation system. The expression of ER-β and p53 were detected in 37 (45.6%) and 48 (57.8%) of the patient tumors, respectively. EGFR mutations were identified in 36 (45.4%) cases. EGFR mutations were more frequently observed in ER-β-negative tumors (26/46; 56.5%), compared with ER-β-positive tumors (10/37; 27%). The expression of ER-β was significantly associated with EGFR mutations with an odds ratio (OR) of 0.241 (P=0.029). However, no significant correlation was observed between the expression of p53 and mutations in EGFR (OR=1.792; P=0.340). In addition, the expression of ER-β and lymph node metastasis were associated with poor prognosis, whereas EGFR mutations were significantly associated with favorable prognosis in terms of progression-free survival rates. However, there was no prognostic significance associated with the expression of p53. In conclusion, the expression of ER-β was significantly correlated with the presence of EGFR mutations. The expression of ER-β and mutations of EGFR were found to be prognostic factors for survival rates in patients with advanced NSCLC.

Exploring estrogenic activity in lung cancer

It is well known that a connection between xenobiotics inhalation, especially tobacco combustion and Lung Cancer development is strongly significant and indisputable. However, recent studies provide evidence indicating that another factors such as, estrogens are also involved in lung carcinoma biology and metabolism. Although the status of estrogen receptors (ER), in both cancerous and healthy lung tissue has been well documented, there is still inconclusive data with respect of which isoform of the receptor is present in the lungs. However according to several studies, ERβ appears to be predominant form. Apart from ERs, estrogens can work through a recently discovered G-coupled estrogen receptor. Binding with both types of the receptors causes a signal, which leads to i.e. enhanced cell proliferation. There are many published reports which suggest that estrogen can be synthesized in situ in lung cancer. Some disturbances in the activity and expression levels of enzymes involved in estrogen synthesis were proved. This suggests that increased amounts of sex-steroid hormones can affect cells biology and be the reason of the accelerated development and pathogenesis of lung cancer. There also exist phenomena which associate estrogenic metabolism and tobacco combustion and its carcinogenic influence on the lungs. Compounds present in cigarette smoke induce the activity of CYP1B1, the enzyme responsible for estrogenic metabolism and synthesis of their cateholic derivatives. These structures during their redox cycle are able to release reactive oxygen species or form DNA adduct, which generally leads to destruction of genetic material. This process may explain the synergistic effect of smoking and estrogens on estrogen-dependent lung cancer development.

Expression of PAM50 Genes in Lung Cancer: Evidence that Interactions between Hormone Receptors and HER2/HER3 Contribute to Poor Outcome

Non–small cell lung cancers (NSCLCs) frequently express estrogen receptor (ER) β, and estrogen signaling is active in many lung tumors. We investigated the ability of genes contained in the prediction analysis of microarray 50 (PAM50) breast cancer risk predictor gene signature to provide prognostic information in NSCLC. Supervised principal component analysis of mRNA expression data was used to evaluate the ability of the PAM50 panel to provide prognostic information in a stage I NSCLC cohort, in an all-stage NSCLC cohort, and in The Cancer Genome Atlas data. Immunohistochemistry was used to determine status of ERβ and other proteins in lung tumor tissue. Associations with prognosis were observed in the stage I cohort. Cross-validation identified seven genes that, when analyzed together, consistently showed survival associations. In pathway analysis, the seven-gene panel described one network containing the ER and progesterone receptor, as well as human epidermal growth factor receptor (HER)2/HER3 and neuregulin-1. NSCLC cases also showed a significant association between ERβ and HER2 protein expression. Cases positive for HER2 expression were more likely to express HER3, and ERβ-positive cases were less likely to be both HER2 and HER3 negative. Prognostic ability of genes in the PAM50 panel was verified in an ERβ-positive cohort representing all NSCLC stages. In The Cancer Genome Atlas data sets, the PAM50 gene set was prognostic in both adenocarcinoma and squamous cell carcinoma, whereas the seven-gene panel was prognostic only in squamous cell carcinoma. Genes in the PAM50 panel, including those linking ER and HER2, identify lung cancer patients at risk for poor outcome, especially among ERβ-positive cases and squamous cell carcinoma.

Prognostic relevance of estrogen receptor α, β and aromatase expression in non-small cell lung cancer

Sex steroids and their receptors are important in the fetal development of normal lung tissue. In addition emerging evidence reveals their significance in lung cancer pathogenesis. This encourages the exploitation of hormone receptors as treatment targets in lung cancer, as it has been successfully used in breast cancer. This study investigates the prognostic impact of estrogen receptor (ER) α and β and the aromatase (AR) enzyme in non-small cell lung cancer (NSCLC) patients. Tumor tissue from 335 NSCLC patients was collected and tissue microarrays (TMAs) were constructed. Immunohistochemical analyses were performed to evaluate the expression of ERα, ERβ and AR in the cytoplasme and nuclei of cells in the tumor epithelial and stromal compartment. By use of survival statistics we investigated the markers impact on disease-specific survival (DSS). Nuclear ERβ expression in tumor epithelial cells in female patients (HR 3.03; 95% CI 1.39-6.61) and tumor cell AR expression in all patients (HR 1.55; 95% CI 1.08-2.23) were significant negative prognostic markers of disease-specific survival in our cohort. High ERβ expression correlates with worse outcome in female patients. Further, patients with high AR expression had an unfavorable prognostic outcome compared with patients expressing low AR levels. These results emphasize the importance of sex steroids role in NSCLC, and, as anti-hormonal drugs are widely available, could lead to the development of novel palliative or even adjuvant treatment strategies in this patient population.

Differential Effects of E2 on MAPK Activity in the Brain and Heart of Aged Female Rats

Aging and the coincident loss of circulating estrogens at menopause lead to increased risks for neurological and cardiovascular pathologies. Clinical studies show that estrogen therapy (ET) can be beneficial in mitigating these negative effects, in both the brain and heart, when it is initiated shortly after the perimenopausal transition. However, this same therapy is detrimental when initiated >10 years postmenopause. Importantly, the molecular mechanisms underlying this age-related switch in ET efficacy are unknown. Estrogen receptors (ERs) mediate the neuroprotective and cardioprotective functions of estrogens by modulating gene transcription or, non-genomically, by activating second messenger signaling pathways, such as mitogen activated protein kinases (MAPK). These kinases are critical regulators of cell signaling pathways and have widespread downstream effects. Our hypothesis is that age and estrogen deprivation following menopause alters the expression and activation of the MAPK family members p38 and ERK in the brain and heart. To test this hypothesis, we used a surgically induced model of menopause in 18 month old rats through bilateral ovariectomy (OVX) followed by an acute dose of 17β-estradiol (E2) administered at varying time points post-OVX (1 week, 4 weeks, 8 weeks, or 12 weeks). Age and E2 treatment differentially regulated kinase activity in both the brain and heart, and the effects were also brain region specific. MAPK signaling plays an integral role in aging, and the aberrant regulation of those signaling pathways might be involved in age-related disorders. Clinical studies show benefits of ET during early menopause but detrimental effects later, which might be reflective of changes in kinase expression and activation status.

Estrogen receptor beta (ERβ) mediates expression of β-catenin and proliferation in prostate cancer cell line PC-3

The aim of the present study was to characterize the mechanism underlying estrogen effects on the androgen-independent prostate cancer cell line PC-3. 17β-estradiol and the ERβ-selective agonist DPN, but not the ERα-selective agonist PPT, increased the incorporation of [methyl-(3)H]thymidine and the expression of Cyclin D2, suggesting that ERβ mediates the proliferative effect of estrogen on PC-3 cells. In addition, upregulation of Cyclin D2 and incorporation of [methyl-(3)H]thymidine induced by 17β-estradiol and DPN were blocked by the ERβ-selective antagonist PHTPP in PC-3 cells. Upregulation of Cyclin D2 and incorporation of [methyl-(3)H]thymidine induced by DPN were also blocked by PKF118-310, a compound that disrupts β-catenin-TCF (T-cell-specific transcription factor) complex, suggesting the involvement of β-catenin in the estradiol effects in PC-3 cells. A diffuse immunostaining for non-phosphorylated β-catenin was detected in the cytoplasm of PC-3 cells. Low levels of non-phosphorylated β-catenin immunostaining were also detected near the plasma membrane and in nuclei. Treatment of PC-3 cells with 17β-estradiol or DPN markedly increased non-phosphorylated β-catenin expression. These effects were blocked by pretreatment with the ERβ-selective antagonist PHTPP, PI3K inhibitor Wortmannin or AKT inhibitor MK-2206, indicating that ERβ-PI3K/AKT mediates non-phosphorylated β-catenin expression. Cycloheximide blocked the DPN-induced upregulation of non-phosphorylated β-catenin, suggesting de novo synthesis of this protein. In conclusion, these results suggest that estrogen may play a role in androgen-independent prostate cancer cell proliferation through a novel pathway, involving ERβ-mediated activation of β-catenin.

Arsenite and Cadmium Activate MAPK/ERK via Membrane Estrogen Receptors and G-Protein Coupled Estrogen Receptor Signaling in Human Lung Adenocarcinoma Cells

Epidemiological evidence indicates that cadmium and arsenic exposure increase lung cancer risk. Cadmium and arsenic are environmental contaminants that act as endocrine disruptors (EDs) by activating estrogen receptors (ERs) in breast and other cancer cell lines but their activity as EDs in lung cancer is untested. Here, we examined the effect of cadmium chloride (CdCl2) and sodium arsenite (NaAsO2) on the proliferation of human lung adenocarcinoma cell lines. Results demonstrated that both CdCl2 and NaAsO2 stimulated cell proliferation at environmentally relevant nM concentrations in a similar manner to 17β-estradiol (E2) in H1793, H2073, and H1944 cells but not in H1792 or H1299 cells. Further studies in H1793 cells showed that 100 nM CdCl2 and NaAsO2 rapidly stimulated mitogen-activated protein kinase (MAPK, extracellular-signal-regulated kinases) phosphorylation with a peak detected at 15 min. Inhibitor studies suggest that rapid MAPK phosphorylation by NaAsO2, CdCl2, and E2 involves ER, Src, epidermal growth factor receptor, and G-protein coupled ER (GPER) in a pertussis toxin-sensitive pathway. CdCl2 and E2 activation of MAPK may also involve ERβ. This study supports the involvement of membrane ER and GPER signaling in mediating cellular responses to environmentally relevant nM concentrations of CdCl2 and NaAsO2 in lung adenocarcinoma cells.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Estrogen Receptor-β Up-Regulates IGF1R Expression and Activity to Inhibit Apoptosis and Increase Growth of Medulloblastoma

Medulloblastoma (Med) is the most common malignant brain tumor in children. The role of ESR2 [estrogen receptor (ER)-β] in promoting Med growth was comprehensively examined in three in vivo models and human cell lines. In a novel Med ERβ-null knockout model developed by crossing Esr2(-/-) mice with cerebellar granule cell precursor specific Ptch1 conditional knockout mice, the tumor growth rate was significantly decreased in males and females. The absence of Esr2 resulted in increased apoptosis, decreased B-cell lymphoma 2 (BCL2), and IGF-1 receptor (IGF1R) expression, and decreased levels of active MAPKs (ERK1/2) and protein kinase B (AKT). Treatment of Med in Ptch1(+/-) Trp53(-/-) mice with the antiestrogen chemotherapeutic drug Faslodex significantly increased symptom-free survival, which was associated with increased apoptosis and decreased BCL2 and IGF1R expression and signaling. Similar effects were also observed in nude mice bearing D283Med xenografts. In vitro studies in human D283Med cells metabolically stressed by glutamine withdrawal found that 17β-estradiol and the ERβ selective agonist 2,3-bis(4-hydroxyphenyl)-propionitrile dose dependently protected Med cells from caspase-3-dependent cell death. Those effects were associated with increased phosphorylation of IGF1R, long-term increases in ERK1/2 and AKT signaling, and increased expression of IGF-1, IGF1R, and BCL2. Results of pharmacological experiments revealed that the cytoprotective actions of estradiol were dependent on ERβ and IGF1R receptor tyrosine kinase activity and independent of ERα and G protein-coupled estrogen receptor 1 (G protein coupled receptor 30). The presented results demonstrate that estrogen promotes Med growth through ERβ-mediated increases in IGF1R expression and activity, which induce cytoprotective mechanisms that decrease apoptosis.

Overexpression of estrogen receptor beta is a prognostic marker in non-small cell lung cancer: a meta-analysis

BACKGROUND

Expression of estrogen receptor beta (ERβ) is a potentially interesting prognostic marker and therapeutic target in non-small cell lung cancer (NSCLC). Although the expression of ERβ has been reported to correlate with better prognosis of NSCLC in most literatures, some controversies still exist. Since the limited patient numbers within independent studies, here we performed a meta-analysis to clarify the correlations between ERβ expression and prognosis in NSCLC.

MATERIALS AND METHODS

We performed a final analysis of 2279 patients from 14 evaluable studies for Prognostic Value of overexpression ERβ (up to October 2014). Data from eligible studies were extracted and included into meta-analysis using a random effects model. Studies were pooled. Summary hazard ratios (HR) were calculated.

RESULTS

Our study shows that the pooled hazard ratio (HR) of overexpression ERβ for overall survival in NSCLC was 0.78 [95% confidence interval (CI): 0.62-0.98] by univariate analysis and 1.06 (95% CI: 0.70-1.61) by multivariate analysis. Pooled HR in American and Japan was 1.09 (95% CI: 0.95-1.25, P=0.239) from 6 studies reported, however, pooled HR was 0.57 (95% CI: 0.46-0.70) outside of American and Japan from 8 studies reported. Pooled HR was 0.75 (95% CI: 0.60-0.94) from 6 studies reported for N-ERβ and 0.76 (95% CI: 0.51-1.12) from 6 Studies reported for C-ERβ.

CONCLUSION

Our results suggested ERβ was significant associated with good overall survival in patients with NSCLC on univariate analysis but not multivariate analysis. ERβ expression is a good prognostic outcome outside of American and Japan. Overexpression of N-ERβ NSCLC patients had better survival. Large prospective studies are now needed to confirm the clinical utility of ERβ as an independent prognostic marker.

Biologic roles of estrogen receptor-β and insulin-like growth factor-2 in triple-negative breast cancer

Triple-negative breast cancer (TNBC) occurs in 10–15% of patients yet accounts for almost half of all breast cancer deaths. TNBCs lack expression of estrogen and progesterone receptors and HER-2 overexpression and cannot be treated with current targeted therapies. TNBCs often occur in African American and younger women. Although initially responsive to some chemotherapies, TNBCs tend to relapse and metastasize. Thus, it is critical to find new therapeutic targets. A second ER gene product, termed ERβ, in the absence of ERα may be such a target. Using human TNBC specimens with known clinical outcomes to assess ERβ expression, we find that ERβ1 associates with significantly worse 5-year overall survival. Further, a panel of TNBC cell lines exhibit significant levels of ERβ protein. To assess ERβ effects on proliferation, ERβ expression in TNBC cells was silenced using shRNA, resulting in a significant reduction in TNBC proliferation. ERβ-specific antagonists similarly suppressed TNBC growth. Growth-stimulating effects of ERβ may be due in part to downstream actions that promote VEGF, amphiregulin, and Wnt-10b secretion, other factors associated with tumor promotion. In vivo, insulin-like growth factor-2 (IGF-2), along with ERβ1, is significantly expressed in TNBC and stimulates high ERβ mRNA in TNBC cells. This work may help elucidate the interplay of metabolic and growth factors in TNBC.

G protein-coupled estrogen receptor (GPER) mediates NSCLC progression induced by 17β-estradiol (E2) and selective agonist G1

Estrogen classically drives lung cancer development via estrogen receptor β (ERβ). However, fulvestrant, an anti-estrogen-based endocrine therapeutic treatment, shows limited effects for non-small cell lung cancer (NSCLC) in phase II clinical trials. G protein-coupled estrogen receptor (GPER), a third estrogen receptor that binds to estrogen, has been found to be activated by fulvestrant, stimulating the progression of breast, endometrial, and ovarian cancers. We here demonstrated that cytoplasm-GPER (cGPER) (80.49 %) and nucleus-GPER (53.05 %) were detected by immunohistochemical analysis in NSCLC samples. cGPER expression was related to stages IIIA-IV, lymph node metastasis, and poorly differentiated NSCLC. Selective agonist G1 and 17β-estradiol (E2) promoted the GPER-mediated proliferation, invasion, and migration of NSCLC cells. Additionally, in vitro administration of E2 and G1 increased the number of tumor nodules, tumor grade, and tumor index in a urethane-induced adenocarcinoma model. Importantly, the pro-tumorigenic effects of GPER induced by E2 were significantly reduced by co-administering the GPER inhibitor G15 and the ERβ inhibitor fulvestrant, as compared to administering fulvestrant alone both in vitro and in vivo. Moreover, the phosphorylation of MAPK and Akt was involved in E2/G1-induced GPER activation. In conclusion, our results indicated that a pro-tumor function of GPER exists that mediated E2-/G1-dependent NSCLC progression and showed better efficiency regarding the co-targeting of GPER and ERβ, providing a rationale for further investigation of anti-estrogen clinical therapy.

Potential therapeutic benefit of combining gefitinib and tamoxifen for treating advanced lung adenocarcinoma

Introduction. Epidermal growth factor receptor (EGFR) mutations are known as oncogene driver mutations and with EGFR mutations exhibit good response to the EGFR tyrosine kinase inhibitor Gefitinib. Some studies have shown that activation of estrogen and estrogen receptor α or β (ERα/β) promote adenocarcinoma. We evaluated the relationship between the two receptors and the potential therapeutic benefit with Gefitinib and Tamoxifen. Methods. We assessed the association between EGFR mutations as well as ERα/β expression/location and overall survival in a cohort of 55 patients with LAC from a single hospital. PC9 (EGFR exon 19 deletion mutant; Gefitinib-vulnerable cells) and A549 (EGFR wild type; Gefitinib-resistant cells) cancer cells were used to evaluate the in vitro therapeutic benefits of combining Gefitinib and Tamoxifen. Results. We found that the cytosolic but not the nuclear expression of ERβ was associated with better OS in LAC tumors but not associated with EGFR mutation. The in vitro study showed that combined Gefitinib and Tamoxifen resulted in increased apoptosis and cytosolic expression of ERβ. In addition, combining both medications resulted in reduced cell growth and increased the cytotoxic effect of Gefitinib. Conclusion. Tamoxifen enhanced advanced LAC cytotoxic effect induced by Gefitinib by arresting ERβ in cytosol.

Estrogen Receptor-β and the Insulin-Like Growth Factor Axis as Potential Therapeutic Targets for Triple-Negative Breast Cancer

Triple-negative breast cancers (TNBCs) lack estrogen receptor-α (ERα), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2) amplification and account for almost half of all breast cancer deaths. This breast cancer subtype largely affects women who are premenopausal, African-American, or have BRCA1/2 mutations. Women with TNBC are plagued with higher rates of distant metastasis that significantly diminish their overall survival and quality of life. Due to their poor response to chemotherapy, patients with TNBC would significantly benefit from development of new targeted therapeutics. Research suggests that the insulin-like growth factor (IGF) family and estrogen receptor beta-1 (ERβ1), due to their roles in metabolism and cellular regulation, might be attractive targets to pursue for TNBC management. Here, we review the current state of the science addressing the roles of ERβ1 and the IGF family in TNBC. Further, the potential benefit of metformin treatment in patients with TNBC as well as areas of therapeutic potential in the IGF-ERβ1 pathway are highlighted.

Down-regulation of MSH2 expression by Hsp90 inhibition enhances cytotoxicity affected by tamoxifen in human lung cancer cells

The anti-estrogen tamoxifen has been used worldwide as an adjuvant hormone therapeutic agent in the treatment of breast cancer. However, the molecular mechanism of tamoxifen-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells has not been identified. Human MutS homolog 2 (MSH2), a crucial element of the highly conserved DNA mismatch repair system, and expression of MSH2 have been down-regulated by Hsp90 function inhibition in human lung cancer. Therefore, in this study, we examined whether MSH2 plays a role in the tamoxifen and Hsp90 inhibitor-induced cytotoxic effect on NSCLC cells. The results showed that treatment with tamoxifen increased MSH2 mRNA and protein levels. The combination treatment with PI3K inhibitors (LY294002 or wortmannin) or knockdown AKT expression by specific small interfering RNA could decrease tamoxifen-induced MSH2 expression. Both knocking down MSH2 expression and co-treatment of PI3K inhibitors enhanced the cytotoxicity and cell growth inhibition of tamoxifen. Compared to a single agent alone, tamoxifen combined with an Hsp90 inhibitor resulted in cytotoxicity and cell growth inhibition synergistically in NSCLC cells, accompanied with reduced MSH2 expression. These findings may have implications for the rational design of future drug regimens incorporating tamoxifen and Hsp90 inhibitors for the treatment of NSCLC.

Estrogen upregulates MICA/B expression in human non-small cell lung cancer through the regulation of ADAM17

Estrogen is involved in promoting lung cancer cell division and metastasis. MICA and MICB function as ligands for NKG2D, an important immunoreceptor expressed on natural killer (NK) cells. However, whether estrogen regulates MICA/B expression and affects tumor immune escape remains unknown. In this study, we measured the mRNA levels of MICA, MICB and ADAM17in non-small cell lung cancer (NSCLC) cell lines treated with estrogen. Surface expression of MICA/B on LTEP-a2 and A549 was detected using flow cytometry. We demonstrate that both mRNA and secretory protein levels of MICA/B in lung adenocarcinoma cell lines were upregulated by estradiol. Estradiol enhanced the expression of ADAM17, which was associated with the secretion of MICA/B. This secretion of MICA/B downregulated the NKG2D receptor on the surface of NK92 cells and impaired the cytotoxic activity of NK cells. Estradiol enhanced the expression of ADAM17, which was associated with the secretion of MICA/B. Furthermore, a significant correlation between the concentration of estradiol and the expression of MICA was found in tumor tissues of NSCLC patients. Therefore, we conclude that estrogen can regulate the expression and secretion of MICA/B through ADAM17, which helps lung cancer cells escape NKG2D-mediated immune surveillance.

Estrogen receptors alpha (ERα) and beta (ERβ): subtype-selective ligands and clinical potential

Estrogen receptors alpha (ERα) and beta (ERβ) are nuclear transcription factors that are involved in the regulation of many complex physiological processes in humans. Modulation of these receptors by prospective therapeutic agents is currently being considered for prevention and treatment of a wide variety of pathological conditions, such as, cancer, metabolic and cardiovascular diseases, neurodegeneration, inflammation, and osteoporosis. This review provides an overview and update of compounds that have been recently reported as modulators of ERs, with a particular focus on their potential clinical applications.