Different estrogen receptor beta expression in distinct histologic subtypes of lung adenocarcinoma. Hum Pathol. 2008;39:1465-1473. [PMID: 18620727 DOI: 10.1016/j.humpath.2008.02.011]

25-hydroxycholesterol promotes proliferation and metastasis of lung adenocarcinoma cells by regulating ERβ/TNFRSF17 axis

Lung adenocarcinoma is the main type of lung cancer in women. Our previous findings have evidenced that 25-hydroxycholesterol (25-HC) promotes migration and invasion of lung adenocarcinoma cells (LAC), during which LXR as a 25-HC receptor plays an important role. Estrogen receptor beta (ERβ) is a receptor of 27-hydroxycholesterol that is structurally analogous to 25-HC, but its role in the functional actions of 25-HC remained largely unknown. In this study, we demonstrated that 25-HC treatment triggered ERβ expression in LAC. Knockdown of ERβ inhibited 25-HC-mediated proliferation, migration and invasion, and reduced 25-HC-induced LAC metastasis in vivo. Further investigation revealed that ERβ knockdown restrained the expression of TNFRSF17 (BCMA). In vivo experiments also confirmed that ERβ knockdown blocked 25-HC-induced TNFRSF17 expression. TNFRSF17 knockdown also restrained 25-HC-induced proliferation, migration and invasion. Bioinformatic analysis showed that the levels of ERβ and TNFRSF17 were elevated in lung adenocarcinoma, and were closely related to tumor stages and nodal metastasis status. These results suggested that 25-HC promoted the proliferation and metastasis of LAC by regulating ERβ/TNFRSF17 axis.

Expression patterns and clinical significance of estrogen receptor in non-small cell lung cancer

BACKGROUND

Lung cancer death remains the highest among all malignancies. Gender differences show women have an increased cancer incidence while men have worse outcomes. These observations identified that some lung carcinomas express estrogen receptors (ER). This is a promising target as antiestrogen drugs can reduce tumors and improve survival. However, there is a limited understanding of ER distribution and its clinical significance to properly design antiestrogen drug clinical trials. Thus, we comprehensively analyzed ERα and ERβ expression patterns by gender, cancer cell type, and receptor location in lung cancer.

METHODS

We conducted a systematic review using the PubMed database from all-time through October 2022, using MeSH terms with the keywords "lung cancer," "estrogen receptor," and "immunohistochemistry." We identified 120 studies with 21 reports being evaluated based on our inclusion criteria.

RESULTS

We examined 4874 lung cancers from 5011 patients. ERβ is the predominant form of ER expressed, mainly found in the nucleus. The ERβ positivity rate is 51.5% in males versus 55.5% in females and was not statistically different. In contrast, ERα is predominately extranuclear in location, and ERα expression varies by gender. Males had a positivity rate of 31% versus 26.6% in females, which is statistically different. ERα is associated with a worse prognosis in some studies, while it had no effect in others. Overall, ERβ was associated with a better prognosis.

CONCLUSION

We characterized ER expression patterns in 4874 lung cancers. Over 50% expressed ERβ with equal rates in both sexes and was associated with a better prognosis. ERα expression was slightly higher in males (31%) than females (26.6%) and was associated with a poor prognosis. Our findings suggest estrogen signaling may be a promising drug target in lung cancer.

Somatic profile in lung cancers is associated to reproductive factors in never-smokers women: Results from the IFCT-1002 BioCAST study

BACKGROUND

Lung cancer in women is on the rise, with a higher proportion occurring in lifelong never-smokers. Lung cancer in never-smokers (LCINS) exhibits a high frequency of driver oncogene alterations. In this study, we aimed to investigate whether exposure to reproductive factors in women with LCINS may modulate the molecular pattern.

METHODS

All newly diagnosed LCINSs were included in a prospective, observational study (IFCT-1002 BioCAST). Each patient responded to a questionnaire including reproductive factors. Biomarker test results were also collected.

RESULTS

Two hundred and sixty women were included in this analysis, and 166 alterations were characterized. EGFR mutation frequency proved greater among patients with late menarche (74% in age>14 vs. 40% and 41% for 12-14 and ≤12 years, respectively; P=0.020) and tended to decrease with increasingly late age at menopause. In multivariate analysis, EGFR mutation frequency increased by 23% per increment of 1 year of age at menarche (P=0.048), and by 9% for each year at age at first birth (P=0.035). ALK alteration frequency was greater in women with high parity (50% in≥5 vs. 12% and 7% for 1-4 and nulliparity, respectively; P=0.021).

CONCLUSION

In a cohort of women LCINSs, female hormonal factors appear to impact molecular pattern.

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.

Hypermethylation of the G protein-coupled receptor kinase 6 (GRK6) promoter inhibits binding of C/EBPα, and GRK6 knockdown promotes cell migration and invasion in lung adenocarcinoma cells

We previously reported that the expression of G protein-coupled receptor kinase 6 (GRK6) is significantly downregulated in lung adenocarcinoma (LADC) tissues, and low expression levels of GRK6 are correlated with poor survival prognosis. However, the specific regulatory mechanisms and functions of GRK6 in LADC remain unknown. Here, we report that GRK6 mRNA expression levels are downregulated in LADC tissues compared to those in matched adjacent non-tumor tissues (P < 0.001). The promoter of the GRK6 gene was found to be hypermethylated in LADC tissues, and its methylation was correlated with both GRK6 expression and pathology grade. GRK6 promoter hypermethylation may predict shorter overall survival. Treatment with 5-aza-2'-deoxycytidine significantly enhanced GRK6 gene expression. Four binding sites of CCAAT/enhancer-binding protein-α (C/EBPα) in the CpG island of the GRK6 gene promoter were predicted in silico, of which three sites were further confirmed by ChIP. Decreased binding of C/EBPα to binding sites 1, 3 and 4 of the GRK6 gene promoter was observed in LADC tissues. Inhibition of C/EBPα significantly inhibited GRK6 expression, while overexpression of C/EBPα significantly promoted GRK6 expression. In addition, overexpression of GRK6 significantly suppressed, while GRK6 knockdown promoted cell migration and invasion. Overexpression of GRK6 enhanced E-cadherin expression and suppressed vimentin expression, and silencing of GRK6 had the opposite effects. Furthermore, ectopic expression of GRK6 significantly decreased matrix metalloproteinase (MMP) 2 and MMP7 protein expression levels. Our findings suggest that hypermethylation of the GRK6 gene promoter suppressed binding of C/EBPα, thereby contributing to the promotion of cell migration and invasion. The methylation status of the GRK6 promoter might be suitable for use as an epigenetic biomarker, and the C/EBPα-GRK6 signaling pathway may be a potential target for LADC.

Speckle-type POZ protein functions as a tumor suppressor in non-small cell lung cancer due to DNA methylation

Background

Tumor suppressor epigenetic silencing plays an important role in non-small cell lung cancer (NSCLC) development and progression. Previously, the expression of speckle-type POZ protein (SPOP) has been found to be significantly inhibited in NSCLC. Our research aimed to investigate the molecular mechanisms, clinical significance and epigenetic alteration of SPOP in NSCLC.

Materials and methods

Bisulfite sequencing PCR and methylation-specific PCR were performed to test gene methylation. Chromatin immunoprecipitation (ChIP) was performed to detect transcription factor C/EBPα combinations and the promoter of the SPOP gene. Furthermore, we evaluated the effects of C/EBPα siRNA on SPOP expression, tumor cell migration and proliferation via MTT and Transwell assays in vitro and tumor growth in vivo. The relationship between the methylation status of the SPOP gene and clinicopathologic characteristics was investigated.

Results

Hypermethylation was found in the CpG island of the SPOP gene promoter in NSCLC tissues, and this methylation was found to be correlated with SPOP expression. SPOP promoter methylation was associated with the pathology grade. The transcriptional activities were significantly inhibited by the hypermethylation of specific CpG sites within the SPOP gene promoter, while 5-aza-2'-deoxycytidine significantly increased SPOP gene expression. C/EBPα also played a key role in SPOP regulation. Five C/EBPα binding sites in the CpG island of the SPOP gene promoter were identified by ChIP. Inhibition of C/EBPα significantly reduced SPOP expression. SPOP mediated the C/EBPα-regulated suppression of invasion, migration and proliferation in vitro and tumor growth in vivo.

Conclusions

SPOP function and expression in NSCLS were regulated by DNA methylation and C/EBPα transcriptional regulation combination effects, indicating that the SPOP promoter methylation status could be utilized as an epigenetic biomarker and that the C/EBPα-SPOP signaling pathway could be a potential therapeutic target in NSCLC.

Metastatic non-small cell lung carcinoma a mimic of primary breast carcinoma-case series and literature review

Metastatic tumors to the breast are rare but constitute a major diagnostic dilemma. Of these, non-mammary carcinomatous metastases to the breast are particularly challenging and, without a clinical history, may be extremely difficult to distinguish from primary breast carcinoma (PBC). We specifically studied metastatic tumors of pulmonary origin, as the lung is one of the major primary sites for carcinomatous metastasis to breast. Sixteen metastatic lung tumors to the breast were identified in our archives between 1996 and 2017 including 12 non-small cell lung carcinomas (NSCLC), one large-cell neuroendocrine, one atypical carcinoid, and two small-cell carcinomas. Adenocarcinoma was the most frequent amongst the NSCLCs (11/14). We retrieved the clinical information of these cases and reviewed the pathological characteristics to provide practical tools for pathologists to aid in their identification. Even in the absence of a clinical history of lung cancer, metastatic pulmonary adenocarcinoma to the breast should be considered in at least one of the following scenarios: (1) single or multiple well-circumscribed lesions of the breast that lack an in situ component and that are accompanied by distant metastases but negative axillary lymph nodes, (2) breast tumors that are triple negative yet not high-grade, or (3) breast tumors presenting as stage 4 disease and/or having an unusually aggressive clinical course on standard breast therapy. Accurate and timely diagnosis of these tumors is mandatory because of treatment and prognostic implications.

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.

Decreased expression of connective tissue growth factor in non-small cell lung cancer is associated with clinicopathological variables and can be restored by epigenetic modifiers

Purpose

Recent studies indicated undisputed contribution of connective tissue growth factor (CTGF) in the development of many cancers, including non-small cell lung cancer (NSCLC). However, the functional role and regulation of CTGF expression during tumorigenesis remain elusive. Our goal was to determine CTGF transcript and protein levels in tumoral and matched control tissues from 98 NSCLC patients, to correlate the results with clinicopathological features and to investigate whether the CTGF expression can be epigenetically regulated in NSCLC.

Methods

We used quantitative PCR, Western blotting and immunohistochemistry to evaluate CTGF expression in lung cancerous and histopathologically unchanged tissues. We tested the impact of 5-Aza-2′-deoxycytidine (5-dAzaC) and trichostatin A (TSA) on CTGF transcript and protein levels in NSCLC cells (A549, Calu-1). DNA methylation status of the CTGF regulatory region was evaluated by bisulfite sequencing. The influence of 5-dAzaC and TSA on NSCLC cells viability and proliferation was monitored by the trypan blue assay.

Results

We found significantly decreased levels of CTGF mRNA and protein (both p < 0.0000001) in cancerous tissues of NSCLC patients. Down-regulation of CTGF occurred regardless of gender in all histological subtypes of NSCLC. Moreover, we showed that 5-dAzaC and TSA were able to restore CTGF mRNA and protein contents in NSCLC cells. However, no methylation within CTGF regulatory region was detected. Both compounds significantly reduced NSCLC cells proliferation.

Conclusions

Decreased expression of CTGF is a common feature in NSCLC; however, it can be restored by the chromatin-modifying agents such as 5-dAzaC or TSA and consequently restrain cancer development.

Electronic supplementary material

The online version of this article (doi:10.1007/s00432-016-2195-3) contains supplementary material, which is available to authorized users.

Fulvestrant-mediated inhibition of estrogen receptor signaling slows lung cancer progression

Estrogens are key signaling molecules that regulate various physiological processes such as cell growth, development, and differentiation. They also play a major role in many pathological conditions, such as hormone-dependent cancer. The importance of inhibiting estrogen receptor signaling in diseases of estrogen target tissues, such as breast cancer, is well documented. However, the role of estrogen signaling in diseases of nontarget tissues, such as lung cancer, is not well characterized. The aim of the current study is to examine the expression of estrogen receptor β (ERβ) and the roles of estradiol (E2) and fulvestrant on the progression of lung cancer. Tissue microarray (TMA) and immunohistochemistry (IHC) analyses were used to detect the expression of aromatase, ERα, and ERβ in 198 patients. We performed analyses to determine if there was any correlation among these three proteins. A mouse model of urethane-induced lung adenocarcinoma was used in the study. Mice were divided into three treatment groups: blank control, E2 alone, and E2 + fulvestrant (ERβ antagonist). Western blot analysis and fluorescence quantitative PCR (FQ-PCR) were used to measure expression of ERβ protein and mRNA levels, respectively. ERβ, but not ERα, was overexpressed in NSCLC samples. Lung cancer progression in mice treated with E2 was significantly increased compared to either the control group or the E2 + fulvestrant group. Mice in the E2 treatment group had significantly increased expression of ERβ at both the mRNA and protein levels compared to mice treated with E2 + fulvestrant or control. Our data suggest that ERβ promotes lung cancer progression in mice and that this progression can be inhibited with fulvestrant. These findings may help elucidate the role of ERβ in lung cancer and suggest that estrogen receptor antagonists, such as fulvestrant, may be therapeutically beneficial for the treatment of the disease.

Estrogen receptors as the novel therapeutic biomarker in non-small cell lung cancer

Although a wide range of studies have addressed the relationship between estrogen receptor (ER) expression and prognosis in non-small cell lung cancer (NSCLC), that relationship remains controversial. This is in large part because there is no consensus on the rate of ER expression in NSCLC or on the intracellular distribution of ER expression. This suggests that establishing the relationship between ER expression and prognosis will require standardization of the antibodies used as well as the definition of a positive response. For example, it is supposed from previous studies that ERs in the cytoplasm and nucleus have different relationships to prognosis than ERs in the cytoplasm. Moreover, ER signaling in NSCLC is known to be affected by aromatase, progesterone receptor and epidermal growth factor receptor mutation. However, there has been little functional analysis these mutants and subtypes. This review will focus on what is known about the role of ERs in NSCLC and whether ER can be a useful prognostic marker or therapeutic target in NSCLC.

Lung cancer in never smokers: disease characteristics and risk factors

It is estimated that approximately 25% of all lung cancer cases are observed in never-smokers and its incidence is expected to increase due to smoking prevention programs. Risk factors for the development of lung cancer described include second-hand smoking, radon exposure, occupational exposure to carcinogens and to cooking oil fumes and indoor coal burning. Other factors reported are infections (HPV and Mycobacterium tuberculosis), hormonal and diatery factors and diabetes mellitus. Having an affected relative also increases the risk for lung cancer while recent studies have identified several single nucleotide polymorphisms associated with increased risk for lung cancer development in never smokers. Distinct clinical, pathology and molecular characteristics are observed in lung cancer in never smokers; more frequently is observed in females and adenocarcinoma is the predominant histology while it has a different pattern of molecular alterations. The purpose of this review is to summarize our current knowledge of this disease.

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

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

Combine therapy of gefitinib and fulvestrant enhances antitumor effects on NSCLC cell lines with acquired resistance to gefitinib

Gefitinib, an EGFR receptor tyrosine kinase inhibitor, is approved for clinical use in the treatment of non-small cell lung cancer (NSCLC), but the emergence of mutations resistant to these inhibitors, such as T790M, has become a clinical problem. According to statistics, female patients, the presence of adenocarcinoma or non-smokers experienced a higher response rate. This may be involved in interaction between the estrogen receptor (ER) and the epidermal growth factor receptor (EGFR). To test whether inhibition of the ER signaling pathway affects the antitumor effect of gefitinib, gefitinib and an ER antagonist, fulvestrant, were administered to NSCLC cell lines with acquired resistance to gefitinib. Compared with treatment of either fulvestrant or gefitinib alone, drug combination obviously decreased proliferation of H1976, H1650 and PC-9 cells coming from adenocarcinoma. Rapid activations of EGFR pathway by E2β were observed in H1975 cells with T790M mutation. Additionally, EGFR and ERs expression were down-regulated respectively in response to estrogen and EGF but up-regulated in response to fulvestrant and gefitinib in vitro. These results suggest that there is a functional cross-signaling between the EGFR/ER pathways in NSCLC with acquired resistance to gefitinib, possibly providing rationale for combining gefitinib with anti-estrogen therapy for advanced NSCLC treatment.

Lung cancer in never smokers--a review

An estimated 10-25% of lung cancers worldwide occur in never smokers, i.e. individuals having smoked less than 100 cigarettes in their lifetime. Lung cancer in never smokers (LCINS) is more frequent in women, although large geographic variations are found. Histologically, adenocarcinomas predominate. The mere existence of LCINS suggests that risk factors other than smoking must be present. Exposure to environmental tobacco smoke (particularly in women) and exposure to workplace carcinogens (particularly in men) are the two most important alternative risk factors. However, a history of either is absent in more than a third of LCINS. The large proportion of women in LCINS suggest a hormonal element that may interact with other identified factors such as hereditary risks, a history of respiratory infections or disease, exposure to air pollution, cooking and heating fumes, or exposure to ionising radiation. The study of genomic polymorphisms finds constitutive DNA variations across subjects according to their smoking status, particularly in genes coding for enzymes that participate in the metabolism of certain carcinogens, in those coding for DNA repair enzymes, or in genes associated with tobacco addiction, or inflammatory processes. The type of molecular mutation in p53 or KRAS varies with smoking status. EGFR mutations are more frequent in never smokers, as are EML4-ALK fusions. The mutually exclusive nature of certain mutations is a strong argument in favour of separate genetic paths to cancer for ever smokers and never smokers. In the present paper we review current clinical and molecular aspects of LCINS.

Estrogen upregulates the IGF-1 signaling pathway in lung cancer through estrogen receptor-β

The estrogen receptor (ER) signaling and the insulin-like growth factor-1 receptor (IGF-1R) signaling are implicated in lung cancer progression. Here, we sought to investigate whether estrogen regulated the IGF-1R signaling in non-small cell lung cancer (NSCLC) and the underlying mechanisms. We examined and analyzed the correlation of the expression of aromatase (Arom), ERβ, ERα, insulin-like growth factor-1 (IGF-1), and IGF-1R in NSCLC. Tissue-microarray and immunohistochemistry analysis of tissue specimens from 162 NSCLC patients and 38 patients with benign pulmonary lesions showed that Arom, ERβ, IGF-1, and IGF-1R were overexpressed while ERα was not expressed in NSCLC. Furthermore, ERβ expression was positively correlated with that of Arom, IGF-1, and IGF-1R (r=0.554, 0.649, 0.496, respectively, P values are equal to 0.000), while Arom expression was positively associated with that of IGF-1 and IGF-1R (r=0.657, 0.714, respectively, P values are equal to 0.000). Additionally, ERβ, IGF-1, and phospho-IGF-1R, but not ERα, were expressed in A549 cells. Immunoblotting assays showed that A549 cells treated with E2 showed significantly higher IGF-1 and p-IGF-1R levels than those receiving the combination treatment of 17β-estradiol (E2) and fulvestrant (Ful, ER antagonist) (P=0.042, 0.002, respectively) or controls (P values are equal to 0.000). The MTT assays further revealed that E2 and IGF-1 synergistically promoted A549 cell proliferation. Together, our study provides the first direct evidence for an interaction between ER and IGF-1R in lung cancer. We showed that estrogen upregulated the IGF-1R signaling through ERβ in lung cancer tissues and A549 cells. These findings shed further light on the mechanisms whereby estrogen promotes lung cancer and highlight the ER and IGF-1R signaling pathways as promising targets for combinational therapy for lung cancer.

[Advances of targeted therapy based on estrogen receptor signaling pathway in lung cancer]

Increasing evidence indicates that estrogen promotes tumor growth in both estrogen target organs and non-target organs. Estrogen regulates cell proliferation and differentiation via two different receptors, estrogen receptors α and β (ERα and ERβ). In recent decades, with the clarification of the ERα-mediated signaling pathways in breast cancer, targeted therapy through these pathways have successfully been used in clinical application. Tamoxifen, the classic representative, is a selective estrogen receptor modulator (SERM). Along with the elucidation of the role of estrogen in the pathophysiology of lung cancer, targeted lung cancer treatment based on the ER signaling pathways is also gradually being applied and it could become an important part of the comprehensive treatment for lung cancer.

Characteristics of lung cancer in women: importance of hormonal and growth factors

Based on epidemiological, clinical, and preclinical data, lung carcinogenesis can be distinctive in women, suggesting that women should be treated differently depending on the expression of various specific biomarkers. We aimed to describe the hormonal and genetic profile of lung cancer in both men and women to identify gender specificities. Primary lung-tumor tissues from surgically treated patients, (50 men, 50 women) were analyzed and compared for expression of estrogen receptors (ER) α and β, progesterone receptors (PR), epidermal growth-factor receptor (EGFR), and HER2 (for EGFR and K-Ras mutations). These data were combined with clinical and outcome data. Fewer women with lung cancer were smokers (p=0.001) and they smoked fewer cigarettes (p=0.001). We observed a higher rate of EGFR mutations (p=0.02) and ERα expression (p=0.006) in women. ERβ and EGFR were also expressed more frequently in women (p=0.29 and p=0.16). HER2 was overexpressed regardless of gender in three men and two women. K-Ras was mutated in 16% of both men and women. Interestingly, there was a positive link between EGFR expression and expression of ERα (p=0.028) and ERβ (p=0.047) in both men and women. Expression of ERα was associated with improved disease-free survival (p=0.007). Our findings provide further evidence on the specificities of lung cancer in women. The differential expression of specific biomarkers, which could be targeted by therapy, favors the development of gender-based treatment guided by biomarker expression.

Oestrogen receptor β in NSCLC - prevalence, proliferative influence, prognostic impact and smoking

In non-small-cell lung carcinoma (NSCLC) there are gender differences. The female gender is associated with more adenocarcinomas (ADCA), among both smokers and non-smokers compared to men. Women with NSCLC have a better prognosis compared to men, regardless of other factors. A possible role for oestrogen receptor (ER) signalling has been proposed. The role for ERβ in NSCLC is still not clear, especially concerning the impact of smoking. In a material of NSCLC (n = 262), ERβ and cyclins A1 and A2 were studied by immunohistochemistry on formalin-fixed paraffin embedded tissue. In 137 of those cases, frozen material was available, on which expression analysis of ESR2 (ERβ) and cyclin A1 were performed. Data were correlated to histology, gender, smoking habits, stage and clinical outcome. ERβ was expressed in 86% of the cases. ERβ was most frequently expressed in Stage I ADCAs, especially in male subjects. A correlation between ERβ expression and cyclins was observed in ADCA, also with a male predominance. ERβ transcripts had a positive prognostic impact in ADCA. ERβ transcripts were increased in NSCLC among smokers compared to non-smokers. In conclusion, our data support a role for ERβ in lung ADCAs, proposing a role for ERβ in lungcarcinogenesis, especially among smokers.

Expression levels of estrogen receptor beta in conjunction with aromatase predict survival in non-small cell lung cancer

Estrogen signaling pathways may play a significant role in the pathogenesis of non-small cell lung cancers (NSCLC) as evidenced by the expression of aromatase and estrogen receptors (ERα and ERβ) in many of these tumors. Here we examine whether ERα and ERβ levels in conjunction with aromatase define patient groups with respect to survival outcomes and possible treatment regimens. Immunohistochemistry was performed on a high-density tissue microarray with resulting data and clinical information available for 377 patients. Patients were subdivided by gender, age and tumor histology, and survival data was determined using the Cox proportional hazards model and Kaplan-Meier curves. Neither ERα nor ERβ alone was predictor of survival in NSCLC. However, when coupled with aromatase expression, higher ERβ levels predicted worse survival in patients whose tumors expressed higher levels of aromatase. Although this finding was present in patients of both genders, it was especially pronounced in women ≥ 65 years old, where higher expression of both ERβ and aromatase indicated a markedly worse survival rate than that determined by aromatase alone. Expression of ERβ together with aromatase has predictive value for survival in different gender and age subgroups of NSCLC patients. This predictive value is stronger than each individual marker alone. Our results suggest treatment with aromatase inhibitors alone or combined with estrogen receptor modulators may be of benefit in some subpopulations of these patients.

Estrogen receptor β

CONTEXT

A new class of estrogen receptors was discovered in 1996 and named estrogen receptor β (ER-B); the traditional estrogen receptor, which until a little more than 10 years ago was thought of as the only estrogen receptor in existence, is now called estrogen receptor α. Estrogen receptor β has at least 5 isoforms, which may have different functions and have different tissue distribution. The significance of ER-B expression in tumors was first demonstrated in breast cancer, with several studies demonstrating that women with ER-B-positive breast cancers treated with adjuvant tamoxifen have better survival, independent of estrogen receptor α expression. Pathologists need to be more aware of this increasingly important protein, as it will soon find its way into routine clinical practice.

OBJECTIVE

To provide pathologists with a concise review of ER-B, with special emphasis on current and potential clinical relevance.

DATA SOURCES

A search of the English literature in PubMed (National Library of Medicine, Bethesda, Maryland) for articles with titles including "estrogen receptor beta," with emphasis on "immunohistochemistry." Abstracts were reviewed, and selected articles were used as the basis for writing this review, mostly based on their relevance to pathology.

CONCLUSIONS

Estrogen receptor β and its isoforms have wider tissue distribution, including the gastrointestinal tract, lung, and brain, than the traditional estrogen receptor, now called estrogen receptor α. Estrogen receptor β expression in breast cancer is associated with favorable outcome in women treated with adjuvant tamoxifen, even in tumors negative for estrogen receptor α. The clinical significance of ER-B expression in tumors other than breast is currently under investigation.

Nuclear vitamin D receptor expression is associated with improved survival in non-small cell lung cancer

Vitamin D has been shown to have anti-proliferative effects in a wide variety of cancers including lung cancer. The anticancer effects of vitamin D are mediated primarily by its active metabolite, 1,25-dihydroxyvitamin D (calcitriol), through vitamin D receptor (VDR) signaling. However, thus far there have been no studies evaluating the association between VDR expression and survival outcome in lung cancer. Using immunohistochemical analysis, we evaluated VDR expression, separately in the nucleus and cytoplasm, in lung cancer samples from 73 non-small cell lung carcinoma (NSCLC) patients with no prior therapy, and investigated the association between VDR expression and overall survival (OS). Cox proportional hazard models were used for our primary analyses. There were 44 deaths during a median follow-up of 51 months (range 13-93 months). High nuclear VDR expression was associated with improved OS after adjusting for age, gender, stage, smoking status, and histology (adjusted hazard ratio, 0.36; 95% confidence interval, 0.17-0.79). There was no association between cytoplasmic VDR expression and OS. Our results suggest that nuclear VDR status may be a prognostic marker in NSCLC. Future large studies to replicate our findings and to assess the impact of VDR gene polymorphisms on VDR expression are required as therapies targeting the vitamin D signaling pathway may be influenced by VDR status in the target lung cancer tissue.

SR16388: a steroidal antiangiogenic agent with potent inhibitory effect on tumor growth in vivo

Angiogenesis is one of the major processes controlling growth and metastasis of tumors. Angiogenesis inhibitors have been targeted for the treatment of various cancers for more than 2 decades. We have developed a novel class of steroidal compounds aimed at blocking the angiogenic process in cancerous tissues. Our lead compound, SR16388, is a potent antiangiogenic agent with binding affinity to estrogen receptor-α (ER-α) and -β (ER-β) at the nanomolar range. This compound inhibited the proliferation of human microvascular endothelial cells (HMVEC) and various types of human cancer cells in vitro. SR16388 inhibited embryonic angiogenesis as measured in the chick chorioallantoic membrane (CAM) assay. The blood vessel density in the CAM was greatly reduced after the embryos were treated with 3 μg/CAM of SR16388 for 24 h. SR16388 at a dose of 2 μM prevented tube formation in Matrigel after HMVEC cells were treated for 8 h. In a modified Boyden chamber assay, SR16388 inhibited the migration of HMVECs by 80% at 500 nM. Using a novel in vivo Fibrin Z-chamber model, we demonstrated that SR16388 at a single daily oral dose of 3 mg/kg for 12 days significantly inhibited the granulation tissue (GT) thickness and the microvessel density of the GT as compared to control. More importantly, SR16388 down-regulated the pro-angiogenic transcription factors, hypoxia inducible factor 1α (HIF-1α) and signal transducer and activator of transcription 3 (STAT3) in non-small cell lung cancer (NSCLC) cells. Together, these effects of SR16388 can lead to the reduction of vascularization and tumor growth in vivo.

Overexpression and gender-specific differences of SRC-3 (SRC-3/AIB1) immunoreactivity in human non-small cell lung cancer: an in vivo study

Steroid receptor coactivator-3 (SRC-3) has been reported to be overexpressed in the development and progression of many tumor types. SRC-3 has been detected in several lung cancer cell lines, but its expression and clinical significance in non-small cell lung cancer (NSCLC) remain unclear. In this study, 48 NSCLC tissues were collected and tissue microarrays were performed. The expression of SRC-3 was examined using nickel-intensified IHC. The results showed that of these 48 cases, 18 (37.5%) exhibited high levels of SRC-3 immunoreactivity, 23 (47.9%) exhibited moderate levels of SRC-3 immunoreactivity, and 7 (14.6%) were negative; thus, the total frequency of SRC-3 overexpression was 85.4% (41/48). This SRC-3 overexpression frequency was similar to the overexpression frequency observed for squamous cell carcinoma and adenocarcinoma (82.1% vs 90%) and for metastasis and non-metastasis patients (84.6% vs 85.7%). Data analysis demonstrated a significantly higher overexpression frequency in male patients compared with that in female patients (88.6% vs 76.9%). However, female patients tended to have higher expression levels of SRC-3, as measured by immunoreactivity, than male patients. These results demonstrate a high frequency of SRC-3 overexpression in NSCLC with a gender difference, suggesting that there is a specific role for SRC-3 in the pathogenesis of NSCLC.

Serum estrogen and tumor-positive estrogen receptor-alpha are strong prognostic classifiers of non-small-cell lung cancer survival in both men and women

The role of tumor estrogen receptors (ERs) and serum estrogen in lung cancer is inconclusive. We investigated the hypothesis that ERs and functional single-nucleotide polymorphisms in the estrogen biosynthesis pathway are associated with poorer lung cancer survival. Lung cancer patients (n = 305) from a National Cancer Institute-Maryland (NCI-MD) case-case cohort in the Baltimore metropolitan area were used as a test cohort. To validate, 227 cases from the NCI-MD case-control cohort and 293 cases from a Norwegian lung cancer cohort were studied. Information on demographics, tobacco and reproductive histories was collected in an interviewer-administered questionnaire. Serum estrogen, progesterone, tumor messenger RNA expression of hormone receptors and germ line DNA polymorphisms were analyzed for associations with lung cancer survival. Patients in the highest tertile of serum estrogen had worse survival in all three cohorts (P combined < 0.001). Furthermore, the variant allele of estrogen receptor alpha (ER-α) polymorphism (rs2228480) was significantly associated with increased tumor ER-α levels and worse survival in all three cohorts [hazard ratio (HR) = 2.59, 95% confidence interval (CI): 1.20- 4.01; HR = 1.76, 95% CI: 1.08-2.87 and HR = 2.85, 95% CI: 1.31-4.36). Other polymorphisms associated with lower serum estrogen correlated with improved survival. Results were independent of gender and hormone replacement therapy. We report a significant association of increased serum estrogen with poorer survival among lung cancer male and female patients. Understanding the genetic control of estrogen biosynthesis and response in lung cancer could lead to improved prognosis and therapy.

Immunohistochemical expression of estrogen receptor in adenocarcinomas of the lung: the antibody factor

BACKGROUND

Immunohistochemistry for estrogen receptor may be used to distinguish metastatic breast cancers from adenocarcinomas of other sites, including those of the lung. The estrogen receptor exists as 2 subtypes, alpha and beta. Estrogen receptor alpha is the predominant subtype expressed by more than two-thirds of human breast cancers. Adenocarcinomas of lung origin may also express estrogen receptor, primarily the beta subtype. Human estrogen receptor alpha is highly homologous to estrogen receptor beta and consequently, antibodies used to detect estrogen receptor alpha in breast carcinomas may detect estrogen receptor beta in pulmonary adenocarcinomas. We investigated the immunohistochemical expression of estrogen receptor in proven primary lung adenocarcinomas using 3 anti-estrogen receptor alpha antibodies: mouse monoclonal 1D5, 6F11, and rabbit monoclonal SP1.

DESIGN

Ninety-two pulmonary adenocarcinomas (53 women and 39 men) confirmed by clinical presentation and positive immunohistochemistry for thyroid transcription factor-1 (TTF-1) were included in this study. There were 19 incisional biopsies and 73 excisional specimens. Immunohistochemistry for estrogen receptor using antibodies 1D5, 6F11, and SP1 was performed on formalin-fixed, paraffin-embedded tissue following antigen retrieval. Any nuclear reactivity for estrogen receptor was considered a positive result.

RESULT

Focal positive nuclear reaction for estrogen receptor was detected in 7 (7.6%) cases of primary pulmonary adenocarcinoma using antibody 1D5, 13 (14.1%) using 6F11, and 25 (27.2%) using SP1. The differences in reactivity for estrogen receptor in pulmonary adenocarcinomas between SP1 and 1D5, and between SP1 and 6F11 were statistically significant (P<0.001). Positive cases showed only a focal pattern of staining with each of the 3 antibodies. There was no significant difference in reactivity for estrogen receptor in pulmonary adenocarcinomas of men and women. Positive staining was highest in nonmucinous bronchioloalveolar adenocarcinomas for all of the antibodies, and for SP1, variation by histologic subtype was significant (P<0.001).

CONCLUSIONS

SP1 has a significantly higher detection rate for the expression of estrogen receptor in pulmonary adenocarcinomas when compared with either 1D5 or 6F11. Caution should therefore be exercised in the use of this antibody alone in distinguishing a metastatic breast from a primary pulmonary adenocarcinoma.

Human papilloma virus and female lung adenocarcinoma

Lung cancer is the leading cause of cancer among women worldwide, and adenocarcinoma is the most common histological subtype among non-smoking women. Previous studies showed that human papillomavirus (HPV) infection may relate to the tumorigenesis of pulmonary adenocarcinoma. Women with anogenital malignancy have a higher risk of lung cancer, which raises the possibility of HPV transmission from the cervix to the lung. Two postulated pathways are discussed in this work. First, HPV may infect the female cervix and then move to the lung by blood circulation. The second transmission route is the HPV infection of oral cavity resulting from dangerous sexual contacts, and subsequently transmitted to the lung. This chapter also reviews the techniques for detecting the existence, subtypes, and viral load of HPV. Future studies are needed to demonstrate the causal inference between HPV infection and the risk of female lung adenocarcinoma.