Estrongenic steroid hormones in lung cancer

Estrogen metabolism in the human lung: impact of tumorigenesis, smoke, sex and race/ethnicity

Previous data from this group demonstrate that the murine lung metabolizes estrogen. Production of the putative carcinogen 4-hydroxyestrogen (4-OHE) is elevated within the lungs of female vs. male mice and accelerated by tobacco smoke. The goal of this study was to determine if the human lung metabolizes estrogen and evaluate the impact of tumor formation, smoke, sex and race/ethnicity on metabolism. Urine and lung tissue (normal, tumor) were obtained from 49 non-small cell lung cancer patients. Healthy postmenopausal Caucasian (n = 19) and Chinese (n = 20) American women (never-smokers) donated urine. Quantitative RT-PCR analyses indicate that multiple estrogen synthesis and metabolism genes are expressed in human bronchoalveolar cells. Estrogen and its metabolites were measured in lung tissue and urine using liquid chromatography/tandem mass spectrometry. Wilcoxon rank tests were used for statistical comparisons. E₁, E₂, E₃ and estrogen metabolites 2-OHE₁, 2-OHE₂, 4-OHE₁, 4-OHE₂, 2-OME₁ and 2-OME₂ were detected at higher levels in tumor vs. adjacent normal tissue and in women vs. men (P < 0.05). The proportion of 4-OHEs was higher in tumors than in normal lung tissue (P < 0.05), and elevated in normal tissue from current- vs. never-smoking women (P = 0.006); similar trends were observed in urine. The proportion of 4-OHEs in the urine of postmenopausal Chinese American women was 1.8-fold higher than that of Caucasian women (P = 0.015). These data indicate that estrogen metabolites are present in the human lung. A shift towards 4-hydroxylation during lung tumorigenesis may contribute to the risk conferred by smoking, sex or race/ethnicity.

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.

G-Protein-Coupled Estrogen Receptor Antagonist G15 Decreases Estrogen-Induced Development of Non-Small Cell Lung Cancer

G-protein-coupled estrogen receptor (GPER) was found to promote non-small cell lung cancer (NSCLC) by estrogen, indicating the potential necessity of inhibiting GPER by a selective antagonist. This study was performed to elucidate the function of GPER-selective inhibitor G15 in NSCLC development. Cytoplasmic GPER (cGPER) and nuclear GPER (nGPER) were detected by immunohistochemical analysis in NSCLC samples. The relation of GPER and estrogen receptor β (ERβ) expression and correlation between GPER, ERβ, and clinical factors were analyzed. The effects of activating GPER and function of G15 were analyzed in the proliferation of A549 and H1793 cell lines and development of urethane-induced adenocarcinoma. Overexpression of cGPER and nGPER was detected in 80.49% (120/150) and 52.00% (78/150) of the NSCLC samples. High expression of GPER was related with higher stages, poorer differentiation, and high expression of ERβ. The protein level of GPER in the A549 and H1793 cell lines was increased by treatment with E2, G1 (GPER agonist), or fulvestrant (Ful; ERβ antagonist) and decreased by G15. Administration with G15 reversed the E2- or G1-induced cell growth by inhibiting GPER. In urethane-induced adenocarcinoma mice, the number of tumor nodules and tumor index increased in the E2 or G1 group and decreased by treatment with G15. These findings demonstrate that using G15 to block GPER signaling may be considered as a new therapeutic target in NSCLC.

Estrogen, Estrogen Receptor and Lung Cancer

Estrogen has been postulated as a contributor for lung cancer development and progression. We reviewed the current knowledge about the expression and prognostic implications of the estrogen receptors (ER) in lung cancer, the effect and signaling pathway of estrogen on lung cancer, the hormone replacement therapy and lung cancer risk and survival, the mechanistic relationship between the ER and the epidermal growth factor receptor (EGFR), and the relevant clinical trials combining the ER antagonist and the EGFR antagonist, to investigate the role of estrogen in lung cancer. Estrogen and its receptor have the potential to become a prognosticator and a therapeutic target in lung cancer. On the other hand, tobacco smoking aggravates the effect of estrogen and endocrine disruptive chemicals from the environment targeting ER may well contribute to the lung carcinogenesis. They have gradually become important issues in the course of preventive medicine.

[Recent Advances in Association of Estrogen and Non-small Cell Lung Cancer]

肺癌是目前发病率及死亡率最高的恶性肿瘤之一，其中约85%为非小细胞肺癌（non-small cell lung cancer, NSCLC）。尽管其治疗手段不断提高，但总体预后不容乐观。既往研究已证实雌激素系统参与了NSCLC的发生、发展。越来越多的证据表明，抗雌激素治疗不仅可以逆转NSCLC患者对铂类化疗药物的耐药性，还可以增加人类表皮生长因子受体酪氨酸激酶抑制剂的疗效。本文就雌激素系统及抗雌激素治疗在NSCLC中的作用作一综述。

Menstrual and reproductive factors and lung cancer risk: A pooled analysis from the international lung cancer consortium

Many clinical features of lung cancer are different in women and men. Sex steroid hormones exert effects in nonreproductive organs, such as the lungs. The association between menstrual and childbearing factors and the risk of lung cancer among women is still debated. We performed a pooled analysis of eight studies contributing to the International Lung Cancer Consortium (4,386 cases and 4,177 controls). Pooled associations between menstrual or reproductive factors and lung cancer were estimated using multivariable unconditional logistic regression. Subgroup analyses were done for menopause status, smoking habits and histology. We found no strong support for an association of age at menarche and at menopause with lung cancer, but peri/postmenopausal women were at higher risk compared to premenopausal (OR 1.47, 95% CI 1.11-1.93). Premenopausal women showed increased risks associated with parity (OR 1.74, 95% CI 1.03-2.93) and number of children (OR 2.88, 95% CI 1.21-6.93 for more than 3 children; p for trend 0.01) and decreased with breastfeeding (OR 0.54, 95% CI 0.30-0.98). In contrast, peri/postmenopausal subjects had ORs around unity for the same exposures. No major effect modification was exerted by smoking status or cancer histology. Menstrual and reproductive factors may play a role in the genesis of lung cancer, yet the mechanisms are unclear, and smoking remains the most important modifiable risk factor. More investigations in large well-designed studies are needed to confirm these findings and to clarify the underlying mechanisms of gender differences in lung cancer risk.

Cancer metastasis: enactment of the script for human reproductive drama

Based on compelling evidence from many biological disciplines, we put forth a hypothesis for cancer metastasis. In the hypothesis, the metastatic cascade is depicted as human reproduction in miniature. Illustrated in a reproductive light, the staggering resemblance of cancer metastasis to human reproduction becomes evident despite some ostensible dis-similarities. In parallel to the appearance of primordial germ cells during early embryogenesis, the cancer reproductive saga starts with the separation of metastasis initiating cells (MICs) from cancer initiating cells when the primary cancer is still in its infancy. Prime MICs embark on a journey to the host bone marrow where they undergo further development and regulation. Migrating MICs are guided by the same CXCR4/CYCL12 axis as used in the migration of primordial germ cells to the genital ridge. Like the ovary, the host bone marrow features immune privileges, coolness, hypoxia and acidity which are essential for stemness maintenance and regulation. Opportune activation of the MICs via fusion with bone marrow stem cells triggers a frenzy of cellular proliferation and sets them on the move again. This scenario is akin to oocyte fertilization in the Fallopian tube and its subsequent journey towards the decidum. Just as the human reproductive process is plagued with undesirable outcomes so is the cancer metastasis highly inefficient. The climax of the cancer metastatic drama (colonization) is reached when proliferating MIC clusters attempt to settle down on decidum-like premetastatic sites. Successfully colonized clusters blossom into overt macrometastases only after the execution of sophisticated immunomodulation, angiogenesis and vascular remodeling. Similarly, the implanted blastomere needs to orchestrate these feats before flourishing into a new life. What is more, the cancer reproductive drama seems to be directed by a primordial hypothalamus–pituitary–gonad axis. Pursuing this reproductive trail could lead to new frontiers and breakthroughs in cancer research and therapeutics.

Women Epidemiology Lung Cancer (WELCA) study: reproductive, hormonal, occupational risk factors and biobank

Background

Lung cancer aetiology and clinical aspects have been mainly studied in men, although specific risk factors probably exist in women. Here we present the rationale, design and organization of the WELCA study (Women Epidemiology Lung CAncer) that has been launched to investigate lung cancer in women, focusing particularly on hormonal and occupational factors.

Methods/Design

WELCA is a population based case-control study and planned to recruit 1000 cases and 1000 controls in three years, based on study power calculation. Eligible cases are female patients newly diagnosed with lung cancer, living in Paris and the Ile de France area and aged up to 75 years. Almost all Parisian pneumology and oncology clinical departments are involved. The control group is a random sample of the population living in the same area, frequency-matched on age and additionally stratified on the distribution of socio-professional categories of women residing there. After acquisition of written consent, research nurses administer standardized computer assisted questionnaires to all the subjects in face-to-face interviews and acquire anthropometric measures. Besides usual socio-demographic characteristics, information is gathered about menstrual and reproductive factors, hormonal treatments, lifestyle and leisure characteristics, occupational history, personal and familial medical history. Biological samples are also collected, in order to establish a biobank for molecular epidemiology studies. Molecular characteristics of the tumours will be obtained and patients will be followed up for five years.

Discussion

The WELCA study aims to answer key questions in lung cancer aetiology and clinical characteristics specifically in women. The role of hormonal impregnation is investigated, and the interactions with cigarette smoking or body mass index (BMI) will be analyzed in detail. The occupational history of the subjects is carefully reconstructed, focusing in particular on the service sector. The creation of a biobank for collection of serum, plasma, DNA and tumour tissue will allow the genetic and biochemical characterization of both the subjets and the tumours. The follow-up of the patients will help in disentangling the role of hormonal factors and tumour molecular characteristics in survival.

Estrogen promotes tumor metastasis via estrogen receptor beta-mediated regulation of matrix-metalloproteinase-2 in non-small cell lung cancer

In non–small cell lung cancer (NSCLC), estrogen significantly promotes NSCLC cell growth via estrogen receptor beta (ERβ). However, the effects by which ERβ contributes to metastasis in NSCLC have not been previously reported. This study aims at defining whether the stimulation of ERβ promotes NSCLC metastasis in vitro and in vivo. Here, Our results showed that estrogen and ERβ agonist enhanced aggressiveness of two lung cancer cell lines (A549 and H1793) and promoted murine lung metastasis formation. ER-inhibitor Fulvestrant treatment or ERβ-knockdown significantly suppressed the migration, invasion and nodule formation of NSCLC cells. The expression level of ERβ protein was analyzed in matched samples of metastatic lymph node and primary tumor tissues from the same individuals, and we found significantly higher levels of ERβ were expressed in lymph node compared to primary tumor tissues. Moreover, Studies on both surgical biopsies and on lung cancer cells revealed that the expression level of ERβ and matrix-metalloproteinase-2 (MMP-2) were associated. Furthermore, inhibition of ERβ resulted in down-regulation of MMP-2 expression. Taken together, our results demonstrate that activation of ERβ in lung cancer cells promotes tumor metastasis through increasing expression of invasiveness-associated MMP-2. These results also highlight the therapeutic potential of inhibition of ERβin the treatment of advanced NSCLC.

Hormone therapy and lung cancer mortality in women: Systematic review and meta-analysis

The mortality of lung cancer presents a significant difference between the sexes. A role of hormone therapy (HT) in lung cancer mortality has been suggested, but the evidence is inconclusive. We sought to elucidate this issue with a meta-analysis. We conducted a systematic literature search in both Pubmed and Embase. Studies that reported the association of HT and mortality of lung cancer cases were included. Pooled hazard ratio (HR) was computed as the effect size to reflect the association between HT and lung cancer mortality. In total, 11 studies were included in the meta-analysis. The pooled HR of HT in relation to lung cancer mortality was 0.97 (95% CI 0.83-1.12, I²=59.2%, p=0.006) in all studies disregarding study design, and it was 0.80 (95% CI: 0.69-0.92, I²=21.4%, p=0.278) in prospective cohort studies. Results of this meta-analysis were robust, and there was no indication of significant differences in association in small and large studies. We observed a protective role of HT use in lung cancer mortality in pooled prospective cohorts, but not in pooled retrospective cohorts and post hoc analyses of randomized controlled trials. Future studies that address smoking, type and time of HT, menopausal status, and histology are warranted.

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.

Evaluation and management of the pregnant patient with suspected primary musculoskeletal tumor or metastatic carcinoma to bone

Primary musculoskeletal cancer and metastatic disease to bone in pregnant patients presents major treatment challenges. Although uncommon, musculoskeletal malignancies in pregnant women have been reported. When diagnosing and treating these patients, the mother's health must be managed appropriately while ensuring that fetal development is not deleteriously affected. Extensive radiographic imaging and more advanced techniques are often necessary to fully characterize the extent of disease. When possible, magnetic resonance imaging should be used instead of computed tomography to limit exposure of the conceptus to radiation. If treatment is needed, therapeutic radiation, chemotherapy, and surgery should be considered. Surgical resection is the foundation of treatment of early-stage primary bone tumors and soft-tissue sarcomas during pregnancy. With surgery, anesthesia and thromboprophylaxis are important considerations. If chemotherapy is required, administration should be avoided in the first trimester to limit harm to the fetus. Therapeutic radiation should similarly be avoided during the first trimester and often can be postponed until after delivery.

Activation of G-Protein-Coupled Estrogen Receptor Inhibits the Migration of Human Nonsmall Cell Lung Cancer Cells via IKK-β/NF-κB Signals

Estrogen signals have been suggested to modulate the progression and metastasis of nonsmall cell lung cancer (NSCLC), which is one of the leading causes of cancer deaths worldwide. While there are limited data concerning the roles and effects of G-protein-coupled estrogen receptor (GPER) on the progression of NSCLC, our present study reveals that the expression of GPER in NSCLC cells is obviously greater than that in lung fibroblast cell line MRC-5. Activation of GPER via its specific agonist G-1 decreases the in vitro motility of A549 and H358 cells and the expression of matrix metalloproteinase 2 (MMP-2) and MMP-9. Further, G-1 treatment can rapidly decrease the phosphorylation, nuclear translocation, and promoter activities of NF-κB in NSCLC cells. BAY 11-7082, the inhibitor of NF-κB, also inhibits the expression of MMP-2/9, while overexpression of p65 significantly attenuates G-1-induced downregulation of MMP-2/9. It suggests that inhibition of NF-κB mediates G-1-induced MMP-2/9 downregulation. G-1 treatment significantly down regulates the phosphorylation of IκB kinase β (IKK-β) and IκBα, while not IKK-α, in both 549 and H358 cells. ACHP, the specific inhibitor of IKK-β, can reinforce G-1-induced MMP-2/9 downregulation and invasion suppression of A549 cells. Collectively, our results suggest that activation of GPER can inhibit the migration of human NSCLC cells via suppression of IKK-β/NF-κB signals. These findings will help to better understand the roles and mechanisms of GPER as a potential therapy target for NSCLC patients.

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.

Estrogen Plus Progestin and Lung Cancer: Follow-up of the Women's Health Initiative Randomized Trial

INTRODUCTION

In the Women's Health Initiative (WHI) estrogen plus progestin trial, after 5.6 years' intervention and 8 years' median follow-up, more women died from lung cancer in the hormone therapy group (hazard ratio [HR], 1.71; 95% confidence interval [CI], 1.16-2.52; P = .01). Now after 14 years' median follow-up, we reexamined combined hormone therapy effects on lung cancer mortality.

PATIENTS AND METHODS

In the WHI placebo-controlled trial, 16,608 postmenopausal women aged 50 to 79 years and with an intact uterus were randomly assigned to once-daily 0.625 mg conjugated equine estrogen plus 2.5 mg medroxyprogesterone acetate (n = 8506) or placebo (n = 8102). Incidence and mortality rates for lung cancer were assessed from multivariant proportional hazard models.

RESULTS

After 14 years' cumulative follow-up, there were 219 lung cancers (0.19% per year) in the estrogen plus progestin group and 184 (0.17%) in the placebo group (HR, 1.12; 95% CI, 0.92-1.37; P = .24). While there were more deaths from lung cancer with combined hormone therapy (153 [0.13%] vs. 132 [0.12%], respectively), the difference was not statistically significant (HR, 1.09; 95% CI, 0.87-1.38; P = .45). The statistically significant increase in deaths from lung cancer observed during intervention in women assigned to estrogen plus progestin was attenuated after discontinuation of study pills (linear trend over time, P = .042).

CONCLUSION

The increased risk of death from lung cancer observed during estrogen plus progestin use was attenuated after discontinuation of combined hormone therapy.

[Advances in Association of Estrogen and Human Non-small Cell Lung Cancer]

肺癌死亡率位居全球癌症之首，其中约85%为非小细胞肺癌（non-small cell lung cancer, NSCLC）。虽然其治疗手段有所提高，但死亡率仍然居高不下。越来越多的证据表明，雌激素及雌激素受体参与了NSCLC的发生和发展。雌激素受体调节剂及芳香化酶抑制剂能够逆转NSCLC患者对铂类化疗药物的耐药性，并能增强表皮生长因子受体的酪氨酸酶抑制剂的疗效。本文就雌激素系统及抗雌激素治疗在NSCLC中的作用作一综述。

MTA1 regulation of ERβ pathway in salivary gland carcinoma cells

Although Metastatic-tumor antigen 1 (MTA1) is differentially expressed in metastatic cancer and coregulates the status and activity of nuclear receptors, its role upon estrogen receptor β (ERβ) - a potent tumor suppressor, remains poorly understood. Here we investigated whether MTA1 regulates the expression and functions of ERβ, an ER isoform predominantly expressed in salivary gland cancer cells. We found that the depletion of the endogenous MTA1 in the HSG and HSY salivary duct carcinoma cell lines enhances the expression of ERβ while MTA1 overexpression augmented the expression of ERβ in salivary duct carcinoma cells. Furthermore, MTA1 knockdown inhibited the proliferations and invasion of HSG and HSY cells. The noted ERβ downregulation by MTA1 overexpression involves the process of proteasomal degradation, as a proteasome inhibitor could block it. In addition, both MTA1 knockdown and ERβ overexpression attenuated the cell migration and inhibited the ERK1/2 signaling in the both cell lines. These findings imply that MTA1 dysregulation in a subset of salivary gland cancer might promote aggressive phenotypes by compromising the tumor suppressor activity of ERβ, and hence, MTA1-ERβ axis might serve a new therapeutic target for the salivary gland cancer.

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.

RNA-sequencing studies identify genes differentially regulated during inflammation-driven lung tumorigenesis and targeted by chemopreventive agents

INTRODUCTION

Chronic pulmonary inflammation has been consistently shown to increase the risk of lung cancer. Therefore, assessing the molecular links between the two diseases and identification of chemopreventive agents that inhibit inflammation-driven lung tumorigenesis is indispensable.

MATERIALS AND METHODS

Female A/J mice were treated with the tobacco smoke carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and lipopolysaccharide (LPS), a potent inflammatory agent and constituent of tobacco smoke, and maintained on control diet or diet supplemented with the chemopreventive agents indole-3-carbinol (I3C) and/or silibinin (Sil). At the end of the study, mice were sacrificed and tumors on the surface of the lung were counted and gene expression levels in lung tissues were determined by RNA sequencing.

RESULTS

The mean number of lung tumors induced by NNK and NNK + LPS was 5 and 15 tumors/mouse, respectively. Dietary supplementation with the combination of I3C and Sil significantly reduced the size and multiplicity (by 50 %) of NNK + LPS-induced lung tumors. Also, we found that 330, 2957, and 1143 genes were differentially regulated in mice treated with NNK, LPS, and NNK + LPS, respectively. The inflammatory response of lung tumors to LPS, as determined by the number of proinflammatory genes with altered gene expression or the level of alteration, was markedly less than that of normal lungs. Among 1143 genes differentially regulated in the NNK + LPS group, the expression of 162 genes and associated signaling pathways was significantly modulated by I3C and/or Sil + I3C. These genes include cytokines, chemokines, putative oncogenes and tumor suppressor genes and Ros1, AREG, EREG, Cyp1a1, Arntl, and Npas2.

CONCLUSION

To our knowledge, this is the first report that provides insight into genes that are differentially expressed during inflammation-driven lung tumorigenesis and the modulation of these genes by chemopreventive agents.

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.

6-OH-BDE-47 promotes human lung cancer cells epithelial mesenchymal transition via the AKT/Snail signal pathway

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been detected in the various human tissues. The OH-PBDEs are suggested to be stronger endocrine-disrupting compounds than PBDEs, therefore the toxicological effects of OH-PBDEs had received lots of attention. However, there is no study about the carcinogenic effect of OH-PBDEs and their estrogen potencies on the tumorigenesis and development of cancer. In the present study, we found that 6-hydroxy-2,2',4',4'-tetrabromodiphenyl ether (6-OH-BDE-47), the most abundant OH-PBDE congeners in human serum, promoted the in vitro migration of lung cancer A549 and H358 cells by induction of epithelial to mesenchymal transition (EMT). This was confirmed by that 6-OH-BDE-47 significantly down regulated the expression of epithelial markers E-cadherin (E-Cad) and zona occludin-1 (ZO-1) while up regulated the mesenchymal markers vimentin (Vim) and N-cadherin (N-Cad). 6-OH-BDE-47 up regulated the protein while not mRNA levels of Snail, which was the key transcription factor of EMT. Silencing of Snail by use of siRNA attenuated the 6-OH-BDE-47 induced EMT. This suggested that the stabilization of Snail was essential for 6-OH-BDE-47 induced EMT. Further, the treatment of 6-OH-BDE-47 increased the phosphorylation of AKT and ERK in A549 cells. Only PI3K/AKT inhibitor (LY294002), but not ERK inhibitor (PD98059), completely blocked the 6-OH-BDE-47 induced up regulation of Snail and down regulation of E-Cad, suggesting that PI3K/AKT pathway is important for 6-OH-BDE-47-mediated Snail stabilization and EMT in A549 cells. Generally, our results revealed for the first time that 6-OH-BDE-47 promoted the EMT of lung cancer cells via AKT/Snail signals. This suggested that more attention should be paid to the effects of OH-PBDEs on tumorigenesis and development of lung cancer.

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.

The expression and correlation between the transcription factor FOXP1 and estrogen receptors in epithelial ovarian cancer

BACKGROUND

Estrogen plays an important role in the progression of ovarian cancer in humans. FOXP1 belongs to the forkhead/winged-helix transcription factor family, and previous research indicated that FOXP1 functioned as a tumor suppressor gene. FOXP1 may be similar to FOXA1 and is closely related to steroid hormone receptors, but the relationship between FOXP1 and ER currently remains unclear.

METHODS

Ovarian tumors (60 malignant cases, 26 borderline cases, and 13 benign cases) and 14 normal ovarian tissues were collected retrospectively. Immunohistochemistry, western blotting and real-time PCR were used to characterize the expression patterns of FOXP1, ERα, and ERβ both at the mRNA and protein levels. We also used co-immunoprecipitation and immunofluorescent colocalization to investigate whether a correlation exists between FOXP1 and ERα/ERβ in ovarian cancer tissues.

RESULTS

The mRNA level for FOXP1 and ERβ in ovarian carcinoma tissues decreased, while the expression level of ERα mRNA increased compared with normal ovarian tissues. With an increase in the degree of ovarian carcinoma malignancy, the ERα expression level also increased. The expression pattern of ERβ in ovarian neoplasms was similar to that of the FOXP1 protein; presenting nuclear staining decreased, while cytoplasmic expression increased. Colocalization of FOXP1, ERα, and ERβ was present in the cytoplasm, with ERβ specific co-localization with FOXP1 in the perinuclear area. While immunoprecipitates created with FOXP1 mouse anti-human monoclonal antibody showed a positive reaction to an anti-ER antibody, immunoprecipitates containing anti-ER antibody and react to anti-FOXP1 antibody.

CONCLUSION

Interactions between FOXP1 and ER may play a pivotal role in the progression of ovarian cancer, and the activation or induction of FOXP1 and ERβ expression in cancer cells may inhibit tumor proliferation.

The inhibition of aromatase alters the mechanical and rheological properties of non-small-cell lung cancer cell lines affecting cell migration

Tumor invasion and metastasis are key aspects of non-small cell lung cancer (NSCLC). During migration, cells undergo mechanical alterations. The mechanical phenotype of breast cancer cells is correlated with aromatase gene expression. We have previously shown that targeting aromatase is a promising strategy for NSCLC. The aim of this study was to examine morphological and mechanical changes of NSCLC cells, upon treatment with aromatase inhibitor and correlate their ability to migrate and invade. In vitro experiments were performed using H23 and A549 NSCLC cell lines and exemestane was used for aromatase inhibition. We demonstrated that exemestane reduced H23 cell migration and invasion and caused changes in cell morphology including increased vacuolar structures and greater pleomorphism. In addition, exemestane changed the distribution of α-tubulin in H23 and A549 cells in a way that might destabilize microtubules polymerization. These effects were associated with increased cell viscosity and decreased elastic shear modulus. Although exemestane caused similar effects in A549 cells regarding viscosity and elastic shear modulus, it did not affect A549 cell migration and caused an increase in invasion. The increased invasion was in line with vimentin perinuclear localization. Our data show that the treatment of NSCLC cells with an aromatase inhibitor not only affects cell migration and invasion but also alters the mechanical properties of the cells. It suggests that the different origin of cancer cells is associated with different morphological characteristics and mechanical behavior.

Menopausal hormone therapy and cancer: changing clinical observations of target site specificity

Menopausal hormone therapy with estrogen plus progestin or estrogen alone (for women with prior hysterectomy) is still used by millions of women for climacteric symptom management throughout the world. Until 2002, hormone therapy influence on cancer risk and other chronic diseases was determined through observational study reports. Since then, results from the Women's Health Initiative randomized, placebo-controlled hormone therapy trials have substantially changed concepts regarding estrogen plus progestin and estrogen alone influence on the most common cancers in postmenopausal women. In these trials, estrogen plus progestin significantly increased breast cancer incidence and deaths from breast cancer, significantly increased deaths from lung cancer, significantly decreased endometrial cancer, and did not have a clinically significant influence on colorectal cancer. In contrast, estrogen alone use in women with prior hysterectomy significantly reduced breast cancer incidence and deaths from breast cancer without significant influence on colorectal cancer or lung cancer. These complex results are discussed in the context of known potential mediating mechanisms of action involved in interaction with steroid hormone receptors.

Specific expression of OATPs in primary small cell lung cancer (SCLC) cells as novel biomarkers for diagnosis and therapy

The expression of organic anion transporting polypeptides (OATPs) was elucidated in cell lines from small cell lung cancer (SCLC) and lung carcinoids and in paraffin-embedded samples from primary and metastatic SCLCs. We found a strong relationship between OATP expression and the origin of the cells, as cells from primary or metastatic SCLC and carcinoid tumors differ with respect to OATP levels. OATP4A1 is most prominent in non-malignant lung tissue and in all SCLC and carcinoid cell lines and tissues, OATP5A1 is most prominent in metastatic cells, and OATP6A1 is most prominent in SCLC cell lines and tumors. Treatment with topotecan, etoposide and cisplatin caused significant changes in the expression patterns of OATP4A1, OATP5A1, OATP6A1, chromogranin and synaptophysin. This effect was also evident in GLC-14 cells from an untreated SCLC patient before chemotherapy compared to GLC-16/-19 chemoresistant tumor cells from this patient after therapy. mRNA expression of OATP4A1, 5A1 and 6A1 correlates with protein expression as confirmed by quantitative microscopic image analysis and Western blots. OATPs might be novel biomarkers for tumor progression and the development of metastasis in SCLC patients.

Cancer risk in women using the levonorgestrel-releasing intrauterine system in Finland

OBJECTIVE

To examine the association between premenopausal use of the levonorgestrel-releasing intrauterine system and cancer incidence in Finland with a special focus on endometrial adenocarcinoma.

METHODS

All Finnish women aged 30-49 years using a levonorgestrel-releasing intrauterine system for treatment of menorrhagia in 1994-2007 (n=93,843) were identified from the National Reimbursement Registry and linked to the Finnish Cancer Registry data. The incidence of cancers in levonorgestrel-releasing intrauterine system users was compared with that in the general population.

RESULTS

A total of 2,781 cancer cases were detected in levonorgestrel-releasing intrauterine system users during the follow-up of 855,324 women-years. The standardized incidence ratio (observed-to-expected ratio) for endometrial adenocarcinoma was 0.50 (95% confidence interval [CI] 0.35-0.70; 34 observed compared with 68 expected cases) after the first levonorgestrel-releasing intrauterine system purchase and 0.25 (95% CI 0.05-0.73; three observed compared with 12 expected cases) after two purchases. The standardized incidence ratio for ovarian cancer was 0.60 (95% CI 0.45-0.76; 59 observed compared with 99 expected cases), for pancreatic cancer 0.50 (95% CI 0.28-0.81; 15 observed compared with 30 expected cases), and for lung cancer 0.68 (95% CI 0.49-0.91; 43 observed compared with 63 expected cases). The standardized incidence ratio for breast cancer among all levonorgestrel-releasing intrauterine system users was 1.19 (95% CI 1.13-1.25; 1,542 observed compared with 1,292 expected cases).

CONCLUSION

The levonorgestrel-releasing intrauterine system may have a protective effect against endometrial malignant transformation. Using the levonorgestrel-releasing intrauterine system for treatment of menorrhagia during reproductive years was associated with a lower incidence of endometrial, ovarian, pancreatic, and lung cancers than expected. Levonorgestrel-releasing intrauterine system use was associated with a higher than expected incidence of breast cancer.

LEVEL OF EVIDENCE

II.

Bisphenol A stimulates human lung cancer cell migration via upregulation of matrix metalloproteinases by GPER/EGFR/ERK1/2 signal pathway

Lung cancer is one of the leading causes of cancer deaths worldwide. Recent evidences indicated that bisphenol A (BPA), a wide contaminant with endocrine disrupting activity, could enhance the susceptibility of carcinogenesis. Although there are increasing opportunities for lung cells exposure to BPA via inhalation, there is no study concerning the effects of BPA on the development of lung cancer. The present study revealed that BPA less than 10(-4)M had limited effects on the proliferation of lung cancer A549 cells, however, BPA treatment significantly stimulated the in vitro migration and invasion of cells combing with the morphological changes and up regulation of matrix metalloproteinase-2 (MMP-2) and MMP-9. G-protein-coupled estrogen receptor (GPER), while not estrogen receptor α/β (ERα/β), mediated the BPA induced up regulation of MMPs. Further, BPA treatment induced rapid activation of ERK1/2 via GPER/EGFR. GPER/ERFR/ERK1/2 mediated the BPA induced upregulation of MMPs and in vitro migration of lung cancer A549 cells. In summary, our data presented here revealed for the first time that BPA can promote the in vitro migration and invasion of lung cancer cells via upregulation of MMPs and GPER/EGFR/ERK1/2 signals, which mediated these effects. This study suggested that more attention should be paid on the BPA and other possible environmental estrogens induced development of lung cancer.