Targeting the estrogen pathway for the treatment and prevention of lung cancer

Unravelling the role of tumor microenvironment responsive nanobiomaterials in spatiotemporal controlled drug delivery for lung cancer therapy

Design and development of efficient drug delivery technologies that impart site-specificity is the need of the hour for the effective treatment of lung cancer. The emergence of materials science and nanotechnology partially helped drug delivery scientists to achieve this objective. Various stimuli-responsive materials that undergo degradation at the pathological tumor microenvironment (TME) have been developed and explored for drug delivery applications using nanotechnological approaches. Nanoparticles (NPs), owing to their small size and high surface area to volume ratio, demonstrated enhanced cellular internalization, permeation, and retention at the tumor site. Such passive accumulation of stimuli-responsive materials helped to achieve spatiotemporally controlled and targeted drug delivery within the tumors. In this review, we discussed various stimuli-physical (interstitial pressure, temperature, and stiffness), chemical (pH, hypoxia, oxidative stress, and redox state), and biological (receptor expression, efflux transporters, immune cells, and their receptors or ligands)-that are characteristic to the TME. We mentioned an array of biomaterials-based nanoparticulate delivery systems that respond to these stimuli and control drug release at the TME. Further, we discussed nanoparticle-based combinatorial drug delivery strategies. Finally, we presented our perspectives on challenges related to scale-up, clinical translation, and regulatory approvals.

17β-estradiol biosensors based on different bioreceptors and their applications

17β-Estradiol (E2) is a critical sex steroid hormone, which has significant effects on the endocrine systems of both humans and animals. E2 is also believed to play neurotrophic and neuroprotective roles in the brain. Biosensors present a powerful tool to detect E2 because of their small, efficient, and flexible design. Furthermore, Biosensors can quickly and accurately obtain detection results with only a small sampling amount, which greatly meets the detection of the environment, food safety, medicine safety, and human body. This review focuses on previous studies of biosensors for detecting E2 and divides them into non-biometric sensors, enzyme biosensors, antibody biosensors, and aptamer biosensors according to different bioreceptors. The advantages, disadvantages, and design points of various bioreceptors for E2 detection are analyzed and summarized. Additionally, applications of different bioreceptors of E2 detection are presented and highlight the field of environmental monitoring, food and medicine safety, and disease detection in recent years. Finally, the development of E2 detection by biosensor is prospected.

Characteristics of Patients With Second Primary Lung Cancer Following Breast Cancer: A Retrospective Descriptive Study

BACKGROUND

Breast cancer (BC) is the most common noncutaneous malignancy in women and survivors are at an increased risk for secondary malignancy with lung cancer (LC) being the most common. There are few studies that have explored the clinicopathological specifics of LC in BC survivors.

METHODS

In this single-institution, retrospective study, we identified BC survivors who subsequently developed LC, examined their breast and LC clinical and pathological characteristics and compared them to the general BC and LC population as published in the literature.

RESULTS

In our study, we found the following associations that could be meaningful: an association between receiving radiation (RT) and LC (including a statistically significant P = .03 chance of ipsilateral LC after BC treatment with RT), a higher incidence and amount of smoking and LC, high BRCA positivity (78.9%) in the few patients who had germline testing, and a higher incidence of EGFR mutations in NSCLC after BC (60.9%) as well as an earlier stage of NSCLC disease.

CONCLUSION

Treatments such as RT, genetic factors such as BRCA mutations, and tobacco use may increase the risk of developing LC amongst BC survivors. Exploring this further can potentially lead to better risk stratification through modified low-dose CT chest screening protocols to catch LCs earlier and ultimately improve outcomes. Past studies have shown that BC survivors who are subsequently diagnosed with NSCLC may have improved OS compared with primary NSCLC and our study showed a high incidence of EGFR mutated NSCLC, which also suggest both improved prognosis and a different molecular profile of NSCLC, which warrants further investigation. Lastly, BC survivors who subsequently are diagnosed with NSCLC had earlier stage disease in our study, perhaps a result of surveillance, highlighting the importance of close monitoring of BC survivors.

Associations between Menopausal Hormone Therapy and Colorectal, Lung, or Melanoma Cancer Recurrence and Mortality: A Narrative Review

Objective: to develop eligibility criteria for use in non-gynecological cancer patients. Methods: We searched all the articles published in peer-reviewed journals up to March 2021. We utilized the PICOS standards and the following selection criteria: menopausal women with a history of non-gynecological and non-breast cancer who underwent hormone replacement therapy (HRT) using various preparations (oestrogens alone or in combination with a progestogen, tibolone, or tissue selective oestrogen complex) and different routes of administration (including oral, transdermal, vaginal, or intra-nasal). We focused on randomized controlled trials as well as relevant extension studies or follow-up reports, specifically examining recurrence and mortality outcomes. Results: Women colorectal cancer survivors who use MHT have a lower risk of death from any cause than those survivors who do not use MHT. Women who are skin melanoma survivors using MHT have a longer survival rate than non-MHT survivors. There is no evidence that women lung cancer survivors who use MHT have a different survival rate than those who do not use MHT. Conclusions: MHT is safe for women who have a history of colorectal, lung, or skin melanoma cancers.

Sex-specificity in Surgical Stages of Lung Cancer in Young Adults

Background

Young Patients with lung cancer represent a distinct subset of patients with this neoplasm. Young International studies show increased lung cancer rates in females, while the incidence in males continues to decline. There is evidence to suggest that this trend recurs in younger patients. We studied the effects of gender differences on the incidence of surgical stages of lung cancer in young adults and its mortality rate.

Methods

This study is a retrospective review (2010-2020) of young adults (aged under 45 years) with surgical-stage of lung cancer. We calculated female-to-male differences in incidence rate ratios, tumor characteristics, surgical management, and survival. Cumulative survival curves were generated by the Kaplan-Meier method.

Results

We examined 46 men and 24 women, under 45 years. Female patients were diagnosed at earlier stages. The proportion of stage IA disease was significantly higher in women than in men (46% versus 13%, respectively) (p=0.03). Women were more likely never smokers (42% versus 83%, p=0.02). A histologic subtype, females were more likely to have typical carcinoid tumors (13.54% versus 10.21% for males) (p>0.05). The largest histological type in men was adenocarcinoma (25.53% versus 4.16%, p>0.05). All the patients were operated. Three men had neoadjuvant chemotherapy and one was operated on for cerebral oligometastatic before his chest surgery. Adjuvant chemotherapy was given to 7 women and 21 men. Despite the small number of postoperative complications in our study (n= 8, 11.2%), the male sex was significant in predicting this complication (p<0.05). The mortality rate was 1.4%. The 5-year overall survival rates were 84% in men and 87% in women.

Conclusion

Our study identified sex differences in the incidence and mortality rates for surgical lung cancers in young adults, but the biological and endocrine mechanisms implicated in these disparities have not yet been determined.

Stearoyl-CoA Desaturases1 Accelerates Non-Small Cell Lung Cancer Metastasis by Promoting Aromatase Expression to Improve Estrogen Synthesis

Metastases contribute to the low survival rate of non-small cell lung cancer (NSCLC) patients. Targeting lipid metabolism for anticancer therapies is attractive. Accumulative evidence shows that stearoyl-CoA desaturases1 (SCD1), a key enzyme in lipid metabolism, enables tumor metastasis and the underlying mechanism remains unknown. In this study, immunohistochemical staining of 96 clinical specimens showed that the expression of SCD1 was increased in tumor tissues (p < 0.001). SCD1 knockdown reduced the migration and invasion of HCC827 and PC9 cells in transwell and wound healing assays. Aromatase (CYP19A1) knockdown eliminated cell migration and invasion caused by SCD1 overexpression. Western blotting assays demonstrated that CYP19A1, along with β-catenin protein levels, was reduced in SCD1 knocked-down cells, and estrogen concentration was reduced (p < 0.05) in cell culture medium measured by enzyme-linked immunosorbent assay. SCD1 overexpression preserving β-catenin protein stability was evaluated by coimmunoprecipitation and Western blotting. The SCD1 inhibitor A939572, and a potential SCD1 inhibitor, grape seed extract (GSE), significantly inhibited cell migration and invasion by blocking SCD1 and its downstream β-catenin, CYP19A1 expression, and estrogen concentration. In vivo tumor formation assay and a tail vein metastasis model indicated that knockdown of SCD1 blocked tumor growth and metastasis. In conclusion, SCD1 could accelerate metastasis by maintaining the protein stability of β-catenin and then promoting CYP19A1 transcription to improve estrogen synthesis. SCD1 is expected to be a promised therapeutic target, and its novel inhibitor, GSE, has great therapeutic potential in NSCLC.

Role of sex hormones in lung cancer

Lung cancer represents the world's leading cause of cancer deaths. Sex differences in the incidence and mortality rates for various types of lung cancers have been identified, but the biological and endocrine mechanisms implicated in these disparities have not yet been determined. While some cancers such as lung adenocarcinoma are more commonly found among women than men, others like squamous cell carcinoma display the opposite pattern or show no sex differences. Associations of tobacco product use rates, susceptibility to carcinogens, occupational exposures, and indoor and outdoor air pollution have also been linked to differential rates of lung cancer occurrence and mortality between sexes. While roles for sex hormones in other types of cancers affecting women or men have been identified and described, little is known about the influence of sex hormones in lung cancer. One potential mechanism identified to date is the synergism between estrogen and some tobacco compounds, and oncogene mutations, in inducing the expression of metabolic enzymes, leading to enhanced formation of reactive oxygen species and DNA adducts, and subsequent lung carcinogenesis. In this review, we present the literature available regarding sex differences in cancer rates, associations of male and female sex hormones with lung cancer, the influence of exogenous hormone therapy in women, and potential mechanisms mediated by male and female sex hormone receptors in lung carcinogenesis. The influence of biological sex on lung disease has recently been established, thus new research incorporating this variable will shed light on the mechanisms behind the observed disparities in lung cancer rates, and potentially lead to the development of new therapeutics to treat this devastating disease.

Epidemiology and clinicopathological features of lung cancer in patients with prior history of breast cancer

Breast cancer is the most common malignancy in women, and lung cancer, the leading cause of cancer-related mortality in the United States, is the most common subsequent primary cancer among breast cancer survivors. In this review, we examine the risk factors that cause subsequent primary lung cancer after breast cancer (referred to herein as BCLC patients) as well as the prognostic factors that may affect survival. Notable clinicopathological features include patient characteristics such as age, smoking history, and the presence of EGFR or BRCA mutations, as well as factors related to the treatment of breast cancer such as radiation, surgery, chemotherapy, stage, anti-estrogen therapy, and ER/PR/HER2 status.

Uncovering the Anti-Lung-Cancer Mechanisms of the Herbal Drug FDY2004 by Network Pharmacology

With growing evidence on the therapeutic efficacy and safety of herbal drugs, there has been a substantial increase in their application in the lung cancer treatment. Meanwhile, their action mechanisms at the system level have not been comprehensively uncovered. To this end, we employed a network pharmacology methodology to elucidate the systematic action mechanisms of FDY2004, an anticancer herbal drug composed of Moutan Radicis Cortex, Persicae Semen, and Rhei Radix et Rhizoma, in lung cancer treatment. By evaluating the pharmacokinetic properties of the chemical compounds present in FDY2004 using herbal medicine-associated databases, we identified its 29 active chemical components interacting with 141 lung cancer-associated therapeutic targets in humans. The functional enrichment analysis of the lung cancer-related targets of FDY2004 revealed the enriched Gene Ontology terms, involving the regulation of cell proliferation and growth, cell survival and death, and oxidative stress responses. Moreover, we identified key FDY2004-targeted oncogenic and tumor-suppressive pathways associated with lung cancer, including the phosphatidylinositol 3-kinase-Akt, mitogen-activated protein kinase, tumor necrosis factor, Ras, focal adhesion, and hypoxia-inducible factor-1 signaling pathways. Overall, our study provides novel evidence and basis for research on the comprehensive anticancer mechanisms of herbal medicines in lung cancer treatment.

Important roles of estrogen receptor alpha in tumor progression and anti-estrogen therapy of pancreatic ductal adenocarcinoma

AIMS

The roles of estrogen receptors (ERs) and the efficacy of anti-estrogen (E2) therapies in pancreatic cancer stay controversial. The main objectives of this study were to investigate the potential roles of ERs in tumor progression and endocrine therapies.

MAIN METHODS

The ER expression status in PANC-1 and SW1990 pancreatic cancer cell lines was determined. SRB assay, colony formation assay and proliferation assay were used to investigate the responses of these cells to E2. ERα-selective agonist propylpyrazoletriol (PPT), ERβ-selective agonist diarylpropionitrile (DPN), ERα over-expressed SW1990 cells, ERα knock-out PANC-1 cells and patient-derived xenografts (PDX) were applied to investigate the potential roles of ERα in pancreatic cancer. The phosphorylation of ERα-related signaling molecules extracellular regulated protein kinases (ERK1/2) and protein kinase B (AKT) were investigated. The in vivo anti-tumor efficacy and safety of letrozole (LTZ) combined with leuprorelin acetate (LA) and gemcitabine (GEM) were also preliminarily studied.

KEY FINDINGS

PANC-1 cells expressed much more ERα than SW1990 cells, and ERβ level was with less diversity. Accordingly, the proliferation of PANC-1 rather than SW1990 cells could be stimulated by E2, and only PANC-1 could respond to LTZ endocrine therapy in female but not male mice. The phosphorylation of ERK1/2 but not AKT was altered by over-expressed or knocking out of ERα with or without the addition of E2 and LTZ. The combination therapy of LTZ and GEM showed acceptable efficacy and safety.

SIGNIFICANCE

This study showed the important roles of ERα in tumor progression and endocrine therapies of pancreatic cancer in women.

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.

Estrogen receptors promote NSCLC progression by modulating the membrane receptor signaling network: a systems biology perspective

Background

Estrogen receptors (ERs) are thought to play an important role in non-small cell lung cancer (NSCLC). However, the effect of ERs in NSCLC is still controversial and needs further investigation. A new consideration is that ERs may affect NSCLC progression through complicated molecular signaling networks rather than individual targets. Therefore, this study aims to explore the effect of ERs in NSCLC from the perspective of cancer systems biology.

Methods

The gene expression profile of NSCLC samples in TCGA dataset was analyzed by bioinformatics method. Variations of cell behaviors and protein expression were detected in vitro. The kinetic process of molecular signaling network was illustrated by a systemic computational model. At last, immunohistochemical (IHC) and survival analysis was applied to evaluate the clinical relevance and prognostic effect of key receptors in NSCLC.

Results

Bioinformatics analysis revealed that ERs might affect many cancer-related molecular events and pathways in NSCLC, particularly membrane receptor activation and signal transduction, which might ultimately lead to changes in cell behaviors. Experimental results confirmed that ERs could regulate cell behaviors including cell proliferation, apoptosis, invasion and migration; ERs also regulated the expression or activation of key members in membrane receptor signaling pathways such as epidermal growth factor receptor (EGFR), Notch1 and Glycogen synthase kinase-3β/β-Catenin (GSK3β/β-Catenin) pathways. Modeling results illustrated that the promotive effect of ERs in NSCLC was implemented by modulating the signaling network composed of EGFR, Notch1 and GSK3β/β-Catenin pathways; ERs maintained and enhanced the output of oncogenic signals by adding redundant and positive-feedback paths into the network. IHC results echoed that high expression of ERs, EGFR and Notch1 had a synergistic effect on poor prognosis of advanced NSCLC.

Conclusions

This study indicated that ERs were likely to promote NSCLC progression by modulating the integrated membrane receptor signaling network composed of EGFR, Notch1 and GSK3β/β-Catenin pathways and then affecting tumor cell behaviors. It also complemented the molecular mechanisms underlying the progression of NSCLC and provided new opportunities for optimizing therapeutic scheme of NSCLC.

The estrogen pathway as a modulator of response to immunotherapy

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

Cytoplasmic ERβ1 expression is associated with survival of patients with Stage IV lung adenocarcinoma and an EGFR mutation at exon 21 L858R subsequent to treatment with EGFR-TKIs

The present study assessed whether estrogen receptor (ER)β1 is associated with the survival of patients with advanced lung adenocarcinoma, with or without mutations of the epidermal growth factor receptor (EGFR) following treatment with EGFR-tyrosine kinase inhibitors (TKIs). Pathologically confirmed stage IV lung adenocarcinomas were assessed for EGFR mutations and ERβ1 expression. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method and the log-rank test. A total of 122 out of the 201 (60.7%) patients had EGFR mutations, 64 (31.8%) of which were EGFR Del19 and 58 mutations (28.9%) were EGFR exon 21 L858R mutation. The presence of EGFR mutations was significantly increased in female patients compared with male patients (P<0.001) and in non-smokers compared with smokers (P<0.001). Patients with EGFR mutations had a significantly improved PFS and OS compared with patients without EGFR mutations treated with EGFR-TKIs. Furthermore, ERβ1 expression was significantly increased in patients with EGFR mutations compared with patients without EGFR mutations (P=0.001). However, the median PFS (P=0.005) and OS (P=0.002) of patients carrying the EGFR exon 21 L858R mutation was significantly decreased in patients with tumors where ERβ1 cytoplasmic expression was high. The multivariate analysis demonstrated that ERβ1 expression was the only independent predictor of PFS (P=0.002) and OS (P=0.003) in patients carrying the EGFR exon 21 L858R mutation. The data demonstrated that ERβ1 expression may predict outcomes of patients with lung adenocarcinoma treated with EGFR-TKI.

17β-estradiol upregulates IL6 expression through the ERβ pathway to promote lung adenocarcinoma progression

Background

In non-small cell lung cancer (NSCLC), estrogen (E2) significantly promotes NSCLC cell growth via estrogen receptor beta (ERβ). Discovery and elucidation of the mechanism underlying estrogen-promoted NSCLC progression is critical for effective preventive interventions. IL6 has been demonstrated to be involved in the development, progression and metastasis in several cancers and IL6 overexpression is associated with poor prognosis in NSCLC. However, the exact role played by IL6 in estrogen-promoted NSCLC progress remain unknown. Here, we evaluated the expression and biological effects of IL6 in NSCLC cells when treated with E2 and explored the underlying mechanism of IL6 in E2-promoted NSCLC progression.

Methods

Expression of ERβ/IL6 in 289 lung cancer samples was assessed by immunohistochemistry. Matched samples of metastatic lymph node and primary tumor tissues were used to quantify the expression of ERβ/IL6 by western blot. Expression levels of IL6 in NSCLC cells were quantified by western blotting, ELISA, and immunofluorescence staining. The effects of IL6 stimulated by E2 on cell malignancy were evaluated using CCK8, colony formation, wound healing and transwell. Furthermore, overexpression and knockdown ERβ constructs were constructed to measure the expression of IL6. The effects of IL6 stimulated by E2 on tumor growth were evaluated using a urethane-induced adenocarcinoma model. In addition, a xenograft mouse model was used to observe differences in ERβ subtype tumor growth with respect to IL6 expression.

Results

IL6/ERβ expression were significantly increased in lung cancer. Higher IL6/ERβ expression was associated with decreased differentiation or increased metastasis. IL6 was an independent prognostic factor for overall survival (OS), higher IL6 expression was associated with decreased OS. Furthermore, ERβ regulates IL6 expression via MAPK/ERK and PI3K/AKT pathways when stimulated by E2 and promotes cell malignancy in vitro and induced tumor growth in vivo. Finally we confirm that ERβ isolation 1/5 is essential for E2 promotion of IL6 expression, while ERβ2 not.

Conclusions

Our findings demonstrate that E2 stimulates IL6 expression to promote lung adenocarcinoma progression through the ERβ pathway. We also clarify the difference in each ERβ subtype for E2 promoting IL6 expression, suggesting that ERβ/IL6 might be potential targets for prognostic assessment and therapeutic intervention in lung cancer.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0804-5) contains supplementary material, which is available to authorized users.

Preclinical Evidence for Combined Use of Aromatase Inhibitors and NSAIDs as Preventive Agents of Tobacco-Induced Lung Cancer

INTRODUCTION

A hormonal role in NSCLC development is well documented. We previously showed that the aromatase inhibitor (AI) anastrozole decreased development of tobacco carcinogen-induced lung tumors in a murine lung cancer prevention model and that aromatase and estrogen receptor were expressed in pulmonary inflammatory cells.

METHODS

We utilized a tobacco carcinogen-induced lung tumor mouse model by treatment with 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone (NNK), to determine whether an AI combined with nonsteroidal anti-inflammatory drugs results in greater lung tumor prevention effects compared to single-agent treatment.

RESULTS

Combination of anastrozole (0.1 mg/kg/d) with aspirin (25 mg/kg/d) after NNK exposure resulted in significantly fewer and smaller lung tumors than did single-agent treatments and was accompanied by maximum decreases in circulating β-estradiol (E2) and interleukin-6, tumor-infiltrating macrophages, and tumoral Ki67, phospho-mitogen-activated protein kinase, phospho-signal transducer and activator of transcription 3, and interleukin-17A expression. Preneoplasia arising after combination treatment showed the lowest Sox-2 expression, suggesting an inhibitory effect on proliferative capacity in the airways by blocking both E2 and inflammation. Anastrozole combined with ibuprofen instead of aspirin also showed enhanced antitumor effects. Moreover, male mice treated with NNK that received E2 in their drinking water showed greater levels of pulmonary macrophages and inflammatory markers than did the control, confirming an E2 effect on inflammation in the microenvironment.

CONCLUSIONS

Our results suggest a benefit to joint targeting of the estrogen and inflammatory pathways for NSCLC prevention. Combining AIs with nonsteroidal anti-inflammatory drugs reduces circulating E2, proinflammatory cytokines, and macrophage recruitment in the lung microenvironment after tobacco exposure. This strategy could be particularly effective in women who have underlying pulmonary inflammatory diseases.

Sex-related differences of urethane and sodium valproate effects on Ki-67 expression in urethane-induced lung tumors of mice

The aim of the present study was to evaluate sex differences in tumorigenesis by assessing the number of Ki-67-positive cells [Ki-67(+)] in urethane-induced mice lung tumors and the effect of sodium valproate (NaVP) in BALB/c mice. Gonad-intact and gonadectomized female and male mice were divided into the following groups: i) Treated with urethane, ii) treated with urethane and NaVP and iii) gonad-intact or gonadectomized control. Urethane (total 50 mg/mouse) was injected intraperitoneally. The NaVP 0.4% solution was administered orally for 6 months. Histologically, lung tumors were divided into adenomas and adenocarcinomas and assessed immunohistochemically using antibodies against Ki-67. The Ki-67(+) was calculated per one mm² of a tumor. In adenomas, Ki-67(+) in the urethane-treated gonad-intact males was significantly higher than in females (P=0.001) and in castrated males (P<0.01); Ki-67(+) in adenomas of the urethane-treated gonad-intact males was significantly higher than in urethane-NaVP-treated ones (P<0.04). No significant differences were found in analogous female groups. In adenocarcinomas, Ki-67(+) in urethane-treated gonad-intact males was significantly higher than in females and gonadectomized mice of both sexes (P<0.001), and in ovariectomized females was significantly higher than in ovary-intact group (P=0.01). A significantly higher number of Ki-67(+) cells were observed in gonad-intact adenocarcinomas of the urethane-NaVP-treated females compared with the urethane-treated ones (P<0.001). Comparing between urethane-NaVP-treated gonadectomized males and females in adenocarcinomas, determined that Ki-67(+) was significantly lower in females (P=0.005). In adenocarcinomas, Ki-67(+) in urethane-NaVP-treated gonadectomized males and females was significantly lower than in gonad-intact mice of the same sex (P<0.001). In summary, gonadectomy with NaVP treatment decreased Ki-67(+) in adenocarcinomas for mice of both sexes. The results of the present study indicate sex-related differences in mice lung tumorigenesis, and a sex-related effect of NaVP on progression in urethane-induced BALB/c mice lung tumors.

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.

Antiestrogen use in breast cancer patients reduces the risk of subsequent lung cancer: A population-based study

BACKGROUND

There is accumulating epidemiological and preclinical evidence that estrogen might be a driver of lung cancer. Breast cancer survivors can offer a unique patient cohort to examine the effect of antiestrogen therapy on lung cancer carcinogenesis because many of these women would have received long-term selective estrogen receptor modulators (SERMs) and/or aromatase inhibitors (AIs) as adjuvant treatment. Our hypothesis is that estrogens play a role in lung cancer development, and that antiestrogen therapy would affect the incidence of subsequent lung cancer among breast cancer survivors.

METHODS

Using the Taiwan National Health Insurance (NHI) database, the study included 40,900 survivors of non-metastatic breast cancer after primary surgery, and most antiestrogen users complied well with the medication regimen. We evaluate the effect of antiestrogen therapy on the incidence of subsequent lung cancers.

RESULTS

This population-based study revealed that antiestrogen use in breast cancer patients was associated with a reduced risk of subsequent lung cancer in older patients (≥50 years) (HR 0.73, 95%CI 0.54-0.99) when compared with breast cancer survivors who did not use antiestrogens.

CONCLUSION

The study supports the hypothesis that antiestrogen therapy modifies lung cancer carcinogenesis in older women. Further well-designed clinical trials to explore the potential of antiestrogens in lung cancer prevention and treatment would be worthwhile.

Identification of informative genes and pathways using an improved penalized support vector machine with a weighting scheme

Incorporation of pathway knowledge into microarray analysis has brought better biological interpretation of the analysis outcome. However, most pathway data are manually curated without specific biological context. Non-informative genes could be included when the pathway data is used for analysis of context specific data like cancer microarray data. Therefore, efficient identification of informative genes is inevitable. Embedded methods like penalized classifiers have been used for microarray analysis due to their embedded gene selection. This paper proposes an improved penalized support vector machine with absolute t-test weighting scheme to identify informative genes and pathways. Experiments are done on four microarray data sets. The results are compared with previous methods using 10-fold cross validation in terms of accuracy, sensitivity, specificity and F-score. Our method shows consistent improvement over the previous methods and biological validation has been done to elucidate the relation of the selected genes and pathway with the phenotype under study.

A potential role for estrogen in cigarette smoke-induced microRNA alterations and lung cancer

Alteration in the expression of microRNAs (miRNAs) is associated with oncogenesis and cancer progression. In this review we aim to suggest that elevated levels of estrogens and their metabolites inside the lungs as a result of cigarette smoke exposure can cause widespread repression of miRNA and contribute to lung tumor development. Anti-estrogenic compounds, such as the components of cruciferous vegetables, can attenuate this effect and potentially reduce the risk of lung cancer (LC) among smokers.

Dexamethasone suppresses the growth of human non-small cell lung cancer via inducing estrogen sulfotransferase and inactivating estrogen

AIM

Dexamethasone (DEX) is a widely used synthetic glucocorticoid, which has shown anti-cancer efficacy and anti-estrogenic activity. In this study we explored the possibility that DEX might be used as an endocrine therapeutic agent to treat human non-small cell lung cancer (NSCLC).

METHODS

The viability and proliferation of human NSCLC cell lines A549 and H1299 were assessed in vitro. Anti-tumor action was also evaluated in A549 xenograft nude mice treated with DEX (2 or 4 mg·kg(-1)·d(-1), ig) or the positive control tamoxifen (50 mg·kg(-1)·d(-1), ig) for 32 d. The expression of estrogen sulfotransferase (EST) in tumor cells and tissues was examined. The intratumoral estrogen levels and uterine estrogen responses were measured.

RESULTS

DEX displayed mild cytotoxicity to the NSCLC cells (IC50 >500 μmol/L) compared to tamoxifen (IC50 <50 μmol/L), but it was able to inhibit the cell proliferation at low micromolar ranges. Furthermore, DEX (0.1-10 μmol/L) dose-dependently up-regulated EST expression in the cells, and inhibited the cell migration in vitro. Triclosan, a sulfation inhibitor, was able to diminish DEX-caused inhibition on the cell viability. In A549 xenograft nude mice, DEX or tamoxifen administration remarkably suppressed the tumor growth. Moreover, DEX administration dose-dependently increased EST expression in tumor tissues, and reduced intratumoral estrogen levels as well as the volumes and weights of uterine.

CONCLUSION

DEX suppresses the growth of A549 xenograft tumors via inducing EST and decreasing estradiol levels in tumor tissues, suggesting that DEX may be used as anti-estrogenic agent for the treatment of NSCLC.

Pharmacological Modulation of Lung Carcinogenesis in Smokers: Preclinical and Clinical Evidence

Many drugs in common use possess pleiotropic properties that make them capable of interfering with carcinogenesis mechanisms. We discuss here the ability of pharmacological agents to mitigate the pulmonary carcinogenicity of mainstream cigarette smoke. The evaluated agents include anti-inflammatory drugs (budesonide, celecoxib, aspirin, naproxen, licofelone), antidiabetic drugs (metformin, pioglitazone), antineoplastic agents (lapatinib, bexarotene, vorinostat), and other drugs and supplements (phenethyl isothiocyanate, myo-inositol, N-acetylcysteine, ascorbic acid, berry extracts). These drugs have been evaluated in mouse models mimicking interventions either in current smokers or in ex-smokers, or in prenatal chemoprevention. They display a broad spectrum of activities by attenuating either smoke-induced preneoplastic lesions or benign tumors and/or malignant tumors. Together with epidemiological data, these findings provide useful information to predict the potential effects of pharmacological agents in smokers.

Estrogen and cancers of the colorectum, breast, and lung in postmenopausal women

As estrogens play an important role in maintaining physiological function in various organs, the estrogen decrease after menopause is thought to cause various diseases frequently observed in postmenopausal or elderly women. With the aging of society and a decrease in infectious or vascular diseases, neoplasms have now become the most frequent cause of death in Japan. Cancers of the colorectum, breast, and lung have been rapidly increasing both in incidence and death, especially among postmenopausal women. Interestingly, all three of these cancers are associated with estrogens. In premenopausal women, ovarian estrogens plays major roles in the female reproductive organs through the classic estrogen receptor, ER-α. In postmenopausal women, however, estrogens produced/activated by peripherally localized estrogen-metabolizing enzymes such as aromatase, which converts androgen into estrogens, are thought to play physiologically and pathobiologically important roles in various organs through second ER, namely ER-β, distributing systemically. In this article, the association of estrogens with these cancers in postmenopausal or elderly women are reviewed, especially focusing on the role of ER-β and peripheral estrogen metabolism. The possibility of prevention or treatment of these diseases through estrogenic control is also discussed.