Antiproliferative effect of exemestane in lung cancer cells

VT204: A Potential Small Molecule Inhibitor Targeting KRASG12C Mutation for Therapeutic Intervention in Non-Small Cell Lung Cancer

Objectives: The development of effective treatments for non-small cell lung cancer (NSCLC), particularly targeting the KRASG12C mutation, remains a challenge. In this study, we investigated the therapeutic potential of VT204, a small molecule inhibitor of KRASG12C, in NSCLC. Methods: To achieve the objectives, we conducted a comprehensive set of experimental methods. In vitro experiments involved the investigation of VT204 on proliferation, apoptosis, cell cycle dynamics, migration, invasion, and on the RAF/MEK/ERK signaling pathway in NCI-H358 cells. In addition, in vivo experiments were performed to evaluate the influence of VT204 on tumor growth. Results: We demonstrated that VT204 effectively suppressed cell proliferation in NCI-H358 cells, with significant inhibition observed at a concentration of 8 μM. Colony formation assays further supported the inhibitory effect of VT204 on NCI-H358 cell growth. Moreover, VT204 exhibited notable effects on suppressing migration and invasion capacities of NCI-H358 cells, indicating its potential as a metastasis-inhibiting agent. Mechanistic investigations revealed that VT204 induced apoptosis and G2M-phase cell cycle arrest in NCI-H358 cells. Additionally, VT204 modulated the RAF/MEK/ERK signaling pathway, leading to reduced phosphorylation of ERK. In vivo studies using xenograft models confirmed the inhibitory effect of VT204 on NCI-H358 tumor growth. Conclusion: These findings highlight VT204 as a promising therapeutic candidate for NSCLC targeting the KRASG12C mutation.

Targeting Estrogens and Various Estrogen-Related Receptors against Non-Small Cell Lung Cancers: A Perspective

Non-small cell lung cancers (NSCLCs) account for ~85% of lung cancer cases worldwide. Mammalian lungs are exposed to both endogenous and exogenous estrogens. The expression of estrogen receptors (ERs) in lung cancer cells has evoked the necessity to evaluate the role of estrogens in the disease progression. Estrogens, specifically 17β-estradiol, promote maturation of several tissue types including lungs. Recent epidemiologic data indicate that women have a higher risk of lung adenocarcinoma, a type of NSCLC, when compared to men, independent of smoking status. Besides ERs, pulmonary tissues both in healthy physiology and in NSCLCs also express G-protein-coupled ERs (GPERs), epidermal growth factor receptor (EGFRs), estrogen-related receptors (ERRs) and orphan nuclear receptors. Premenopausal females between the ages of 15 and 50 years synthesize a large contingent of estrogens and are at a greater risk of developing NSCLCs. Estrogen-ER/GPER/EGFR/ERR-mediated activation of various cell signaling molecules regulates NSCLC cell proliferation, survival and apoptosis. This article sheds light on the most recent achievements in the elucidation of sequential biochemical events in estrogen-activated cell signaling pathways involved in NSCLC severity with insight into the mechanism of regulation by ERs/GPERs/EGFRs/ERRs. It further discusses the success of anti-estrogen therapies against NSCLCs.

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

Introduction

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

Methods

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

Results

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

Conclusions

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

Differential Interactome Based Drug Repositioning Unraveled Abacavir, Exemestane, Nortriptyline Hydrochloride, and Tolcapone as Potential Therapeutics for Colorectal Cancers

There is a critical requirement for alternative strategies to provide the better treatment in colorectal cancer (CRC). Hence, our goal was to propose novel biomarkers as well as drug candidates for its treatment through differential interactome based drug repositioning. Differentially interacting proteins and their modules were identified, and their prognostic power were estimated through survival analyses. Drug repositioning was carried out for significant target proteins, and candidate drugs were analyzed via in silico molecular docking prior to in vitro cell viability assays in CRC cell lines. Six modules (mAPEX1, mCCT7, mHSD17B10, mMYC, mPSMB5, mRAN) were highlighted considering their prognostic performance. Drug repositioning resulted in eight drugs (abacavir, ribociclib, exemestane, voriconazole, nortriptyline hydrochloride, theophylline, bromocriptine mesylate, and tolcapone). Moreover, significant in vitro inhibition profiles were obtained in abacavir, nortriptyline hydrochloride, exemestane, tolcapone, and theophylline (positive control). Our findings may provide new and complementary strategies for the treatment of CRC.

Oxymestane, a cytostatic steroid derivative of exemestane with greater antitumor activity in non-estrogen-dependent cell lines

A new promising steroid derivative of Exemestane (Exe), the drug used for the treatment of estrogen-dependent breast cancer, was synthesized and evaluated against a set of human cancer cell lines. The new compound (Oxymestane-D1, Oxy) was tested comparatively with Exe against colon (C2BBe1, WiDr), liver (HepG2, HuH-7), lung (A549, H1299) and prostate (LNCaP, PC3) human cancer cell lines. Likewise, its effect on human colon normal cells (CCD-841 CoN) and human normal fibroblast cells (HFF-1) was studied. The cytostatic activity of Oxy was also compared with that of the reference cytostatic drugs used in chemotherapy protocols, namely carboplatin, cisplatin, doxorubicin, epirubicin, etoposide, flutamide, 5-fluorouracil, irinotecan, oxaliplatin and sorafenib. In all cell lines tested, Oxy proved to be more powerful cytostatic than Exe. Additionally, the IC₅₀ at 72 h showed a three-fold activity greater than 5-fluorouracil in the WiDr cell line, twice as high as cisplatin for cell line A549 and five times higher than cisplatin for cell line H1299. Also, Oxy surprisingly revealed to induce DNA damage and inhibit the DNA damage response (DDR) proteins ATM, ATR, CHK1 and CHK2. The results obtained allow concluding that Oxy can be a promising anticancer agent to be used in chemotherapy protocols. Furthermore, its ability to inhibit crucial components of DDR can also be useful for the monotherapy or for combination with chemo and/or radiotherapy of cancer.

Plausible Role of Estrogens in Pathogenesis, Progression and Therapy of Lung Cancer

Malignant neoplasms are among the most common diseases and are responsible for the majority of deaths in the developed world. In contrast to men, available data show a clear upward trend in the incidence of lung cancer in women, making it almost as prevalent as breast cancer. Women might be more susceptible to the carcinogenic effect of tobacco smoke than men. Furthermore, available data indicate a much more frequent mutation of the tumor suppressor gene-p53 in non-small cell lung cancer (NSCLC) female patients compared to males. Another important factor, however, might lie in the female sex hormones, whose mitogenic or carcinogenic effect is well known. Epidemiologic data show a correlation between hormone replacement therapy (HRT) or oral contraceptives (OCs), and increased mortality rates due to the increased incidence of malignant tumors, including lung cancer. Interestingly, two types of estrogen receptors have been detected in lung cancer cells: ERα and ERβ. The presence of ERα has been detected in tissues and non-small-cell lung carcinoma (NSCLC) cell lines. In contrast, overexpression of ERβ is a prognostic marker in NSCLC. Herein, we summarize the current knowledge on the role of estrogens in the etiopathogenesis of lung cancer, as well as biological, hormonal and genetic sex-related differences in this neoplasm.

NCS 613, a Potent PDE4 Inhibitor, Displays Anti-Inflammatory and Anti-Proliferative Properties on A549 Lung Epithelial Cells and Human Lung Adenocarcinoma Explants

Chronic inflammation is a deleterious process occurring in several pulmonary diseases; it is a driving force promoting tumorigenesis. By regulating local cyclic nucleotide concentration, cyclic nucleotide phosphodiesterases (PDE) govern important biological processes, including inflammation and proliferation. The aim of this study was to investigate the anti-inflammatory and anti-proliferative effects of NCS 613, a specific PDE4 inhibitor, on TNFα-treated human lung adenocarcinoma cell line (A549) and on human lung adenocarcinoma explants. PDE4 isoforms and inflammatory pathways mediated by p38 MAPK, ERK1/2, and IκBα were analyzed by Western blot and immunostainings. Proliferation were performed using [³H]-thymidine incorporation under different experimental conditions. TNFα-stimulation increased p38 MAPK phosphorylation and NF-κB translocation into the nucleus, which was abolished by NCS 613 treatment. Concomitantly, NCS 613 restores IκBα detection level in human adenocarcinoma. An IC₅₀ value of 8.5 μM was determined for NCS 613 on anti-proliferative properties while ERK1/2 signaling was down-regulated in A549 cells and lung adenocarcinoma explants. These findings shed light on PDE4 signaling as a key regulator of chronic inflammation and cancer epithelial cell proliferation. It suggests that PDE4 inhibition by NCS 613 represent potential and interesting strategy for therapeutic intervention in tackling chronic inflammation and cell proliferation.

Sex steroid metabolism and actions in non-small cell lung carcinoma

Despite recent development in targeted therapies, lung cancer still remains the leading cause of cancer death. Therefore, a better understanding of its pathogenesis and progression could contribute to improving the eventual clinical outcome of the patients. Results of recently published several in vitro and clinical studies indicated the possible involvement of sex steroids in both development and progression of non-small cell lung carcinoma (NSCLC). Therefore we summarized the reported clinical relevant information of the sex steroids, their receptors and steroid metabolizing enzymes related to NSCLC in this mini-review. In addition, we also reviewed the potential "endocrine therapy", targeting sex steroid actions and/or metabolism in NSCLC patients.

Influence of estrogen in non-small cell lung cancer and its clinical implications

Lung cancer (LC) is the leading cause of cancer death in men worldwide and has significantly increased in women. Differences in non-small cell lung cancer (NSCLC) behavior, prognosis, and response to treatment have been reported by sex and hormonal status, with premenopausal women presenting the worst prognosis compared to postmenopausal women and men. Additionally, the use of hormonal replacement therapy significantly increases NSCLC mortality; supporting the role of estrogen signaling in the pathogenesis of LC. The mechanisms by which estrogen promotes lung carcinogenesis have not been fully elucidated. Estrogen, through its receptor, can stimulate LC cell proliferation, death resistance, angiogenesis, migration and metastasis. Estrogen also induces expression of pro-inflammatory proteins and ligands that promote tumor evasion, suggesting that estrogen might modify the microenvironment and anti-tumor immune response. Recent reports have shown an interaction between the epidermal growth factor receptor (EGFR) pathway and estrogen signaling in lung adenocarcinoma, whence, combined treatment based on tyrosine kinase inhibitors (TKIs) and antiestrogen therapy is beginning to be evaluated. This review focuses on the differences in NSCLC behavior by sex and hormonal status, highlighting the role of estrogen and its receptors in lung carcinogenesis and LC prognosis. Due to the importance of estrogen in NSCLC development and progression we finally discuss the potential of antiestrogen therapy in LC treatment and show the results from preclinical and clinical trials.

Exemestane Attenuates Hepatic Fibrosis in Rats by Inhibiting Activation of Hepatic Stellate Cells and Promoting the Secretion of Interleukin 10

Exemestane (EXE) is an irreversible steroidal aromatase inhibitor mainly used as an adjuvant endocrine therapy for postmenopausal women suffering from breast cancer. Besides inhibiting aromatase activity, EXE has multiple biological functions, such as antiproliferation, anti-inflammatory, and antioxidant activities which are all involved in hepatic fibrosis. Therefore, we investigated the role of EXE during the progress of hepatic fibrosis. The effect of EXE on liver injury and fibrosis were assessed in two hepatic fibrosis rat models, which were induced by either carbon tetrachloride (CCl₄) or bile duct ligation (BDL). The influence of EXE treatment on activation and proliferation of primary rat hepatic stellate cells (HSCs) was observed in vitro. The results showed that EXE attenuated the liver fibrosis by decreasing the collagen deposition and α-SMA expression in vivo and inhibited the activation and proliferation of primary rat HSCs in vitro. Additionally, EXE promoted the secretion of antifibrotic and anti-inflammatory cytokine IL-10 in vivo and in HSC-T6 culture media. In conclusion, our findings reveal a new function of EXE on hepatic fibrosis and prompted its latent application in liver fibrotic-related disease.

Synchronous Multiple Lung Adenocarcinomas: Estrogen Concentration in Peripheral Lung

BACKGROUND

The detection rate of synchronous multiple lung adenocarcinomas (SMLA), which display multiple ground glass opacity nodules in the peripheral lung, is increasing due to advances in high resolution computed tomography. The backgrounds of multicentric development of adenocarcinoma are unknown. In this study, we quantitated estrogen concentration in the peripheral lungs of postmenopausal female patients with SMLA.

METHODS

The tissue concentration of estrogens (estrone [E1] and estdadiol [E2]) in the noncancerous peripheral lung were measured with liquid chromatography/electrospray tandem mass spectrometry in postmenopausal female patients with lung adenocarcinoma. The expression levels of CYP19A1 in the normal lung were also quantitated with real-time PCR. Thirty patients with SMLA and 79 cases of control patients with single lung adenocarcinoma were analyzed.

RESULTS

The concentrations of E1 and E2 in the noncancerous tissue were significantly higher in SMLA cases than control cases (P = 0.004 and P = 0.02, respectively). The minor allele (A) of single nucleotide polymorphism rs3764221 were significantly associated with higher concentration of E1 and E2 (P = 0.002 and P = 0.01, respectively) and higher CYP19A1 mRNA expression (P = 0.03).

CONCLUSION

The tissue estrogen concentration of peripheral lung was significantly higher in SMLA than control cases. The high concentration of estrogen may be one of the causes of multicentric development of peripheral lung adenocarcinomas.

A gene-signature progression approach to identifying candidate small-molecule cancer therapeutics with connectivity mapping

Background

Gene expression connectivity mapping has gained much popularity recently with a number of successful applications in biomedical research testifying its utility and promise. Previously methodological research in connectivity mapping mainly focused on two of the key components in the framework, namely, the reference gene expression profiles and the connectivity mapping algorithms. The other key component in this framework, the query gene signature, has been left to users to construct without much consensus on how this should be done, albeit it has been an issue most relevant to end users. As a key input to the connectivity mapping process, gene signature is crucially important in returning biologically meaningful and relevant results. This paper intends to formulate a standardized procedure for constructing high quality gene signatures from a user’s perspective.

Results

We describe a two-stage process for making quality gene signatures using gene expression data as initial inputs. First, a differential gene expression analysis comparing two distinct biological states; only the genes that have passed stringent statistical criteria are considered in the second stage of the process, which involves ranking genes based on statistical as well as biological significance. We introduce a “gene signature progression” method as a standard procedure in connectivity mapping. Starting from the highest ranked gene, we progressively determine the minimum length of the gene signature that allows connections to the reference profiles (drugs) being established with a preset target false discovery rate. We use a lung cancer dataset and a breast cancer dataset as two case studies to demonstrate how this standardized procedure works, and we show that highly relevant and interesting biological connections are returned. Of particular note is gefitinib, identified as among the candidate therapeutics in our lung cancer case study. Our gene signature was based on gene expression data from Taiwan female non-smoker lung cancer patients, while there is evidence from independent studies that gefitinib is highly effective in treating women, non-smoker or former light smoker, advanced non-small cell lung cancer patients of Asian origin.

Conclusions

In summary, we introduced a gene signature progression method into connectivity mapping, which enables a standardized procedure for constructing high quality gene signatures. This progression method is particularly useful when the number of differentially expressed genes identified is large, and when there is a need to prioritize them to be included in the query signature. The results from two case studies demonstrate that the approach we have developed is capable of obtaining pertinent candidate drugs with high precision.

Electronic supplementary material

The online version of this article (doi:10.1186/s12859-016-1066-x) contains supplementary material, which is available to authorized users.

Prognostic significance of aromatase and estrogen receptor beta expression in EGFR wild-type lung adenocarcinoma

OBJECTIVES

Based on recent findings of aromatase and estrogen receptor beta (ERβ) expression in non-small-cell lung cancer, we assessed the clinicopathological and prognostic significance of aromatase and ERβ expression and their relationship to epidermal growth factor receptor (EGFR) mutation in lung adenocarcinoma.

MATERIALS AND METHODS

We evaluated 150 resected primary lung adenocarcinoma specimens. Expression of aromatase, ERα, ERβ, progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) was evaluated by immunostaining, and EGFR and KRAS mutations were analyzed. Overall survival (OS) and recurrence-free survival (RFS) were calculated using the Kaplan-Meier method.

RESULTS

Expression of aromatase, ERα, ERβ, PR, and HER2 was detected in 88.0%, 1.3%, 79.3%, 2.7%, and 39.3% of specimens, respectively. In patients with EGFR wild-type lung adenocarcinoma, high aromatase expression was an independent predictor of poor OS (hazard ratio [HR]=2.638; 95% confidence interval [CI], 1.173-5.936; P=.019) and RFS (HR=2.505; 95% CI, 1.154-5.434; P=.020). Positive ERβ expression was also an independent predictor of poor RFS (HR=4.013; 95% CI, 1.219-13.207; P=.022). Furthermore, high aromatase expression was a significant predictor of poor survival only in females (OS, P=.010; RFS, P=.007), whereas positive ERβ expression was an important predictor of poor survival only in males (OS, P=.073; RFS, P=.051). No prognostic significance was observed in patients with EGFR mutations.

CONCLUSIONS

Our findings suggest that EGFR wild-type lung adenocarcinoma is an estrogen-dependent carcinoma, and aromatase expression and ERβ expression are potent prognostic markers for EGFR wild-type lung adenocarcinoma.

Epidermal growth factor receptor status and Notch inhibition in non-small cell lung cancer cells

BACKGROUND

Notch may behave as an oncogene or a tumor suppressor gene in lung cancer cells. Notch receptor undergoes cleavage by enzymes, including γ-secretase, generating the active Notch intracellular domain (NICD). The aim of the present study was to investigate the effect of DAPT, a γ-secretase inhibitor, in non-small cell lung cancer (NSCLC) cells, as well as the impact of epidermal growth factor (EGF) that is over-expressed by NSCLC cells, on Notch signaling. H23, A549, H661 and HCC827 human NSCLC cell lines were used, expressing various NICD and EGF receptor (EGFR) protein levels.

RESULTS

DAPT decreased the number of H661 cells in a concentration-dependent manner, while it had a small effect on H23 and A549 cells and no effect on HCC827 cells that carry mutated EGFR. Notch inhibition did not affect the stimulatory effect of EGF on cell proliferation, while EGF prevented DAPT-induced NICD decrease in H23 and H661 cells. The type of cell death induced by DAPT seems to depend on the cell type.

CONCLUSIONS

Our data indicate that inhibition of Notch cleavage may not affect cell number in the presence of EGFR mutations and that EGFR may affect Notch signalling suggesting that a dual inhibition of these pathways might be promising in NSCLC.

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.

Prognostic and therapeutic implications of aromatase expression in lung adenocarcinomas with EGFR mutations

PURPOSE

Lung adenocarcinomas among never-smokers are more common in females than in males. This implies that gender-dependent hormones promote smoking unrelated lung adenocarcinoma. We therefore investigated mRNA expression of aromatase, an intrinsic estrogen synthetase, in lung adenocarcinoma and assessed its correlation to clinicopathologic factors, including EGFR mutations and postsurgical prognosis.

EXPERIMENTAL DESIGN

Aromatase mRNA expression in primary tumor samples from 110 patients with lung adenocarcinoma was evaluated with qRT-PCR. Inhibitory effects of the aromatase inhibitor exemestane were assessed in lung adenocarcinoma cell lines (11-18 and HCC4006), which have EGFR mutations, separately and combined with EGFR tyrosine kinase inhibitor erlotinib.

RESULTS

Aromatase gene expression was not correlated with patients' clinicopathologic factors, including EGFR mutation status. High aromatase expression was associated with poor prognosis for both recurrence-free survival (P = 0.004) and overall survival (P = 0.003). In addition, the prognostic significance of aromatase expression was limited to females, never-smokers, and patients with EGFR mutations, but not in their counterparts. HCC4006, which has a low aromatase mRNA expression level, was not sensitive to exemestane, either alone or combined with erlotinib. In contrast, growth of 11-18 cells, which have high aromatase expression, was significantly inhibited by exemestane, both alone and combined with erlotinib.

CONCLUSIONS

Aromatase is a candidate prognostic factor in patients with lung adenocarcinoma, especially in those with EGFR mutations, and may also be a beneficial therapeutic target in those patients.

Exemestane blocks mesothelioma growth through downregulation of cAMP, pCREB and CD44 implicating new treatment option in patients affected by this disease

Background

Recent evidence suggests that aromatase may be involved in the pathogenesis of malignant mesothelioma. Here, we evaluated the effect of exemestane, an inhibitor of aromatase, in the treatment of mesothelioma using in vitro and in vivo preclinical models.

Results

We show a significant reduction of cell proliferation, survival, migration and block of cells in S phase of cell cycle in mesothelioma cells upon exemestane treatment. Moreover, we find that CD44, which is involved in mesothelioma cells migration, was modulated by exemestane via cAMP and pCREB. Most importantly, in mice mesothelioma xenograft exemestane causes a significant decrease in tumor size and the association pemetrexed/exemestane is more effective than pemetrexed/cisplatin.

Conclusion

The preclinical mesothelioma model suggests that exemestane might be beneficial in mesothelioma treatment.

Association of a genetic variant of CYP19A1 with multicentric development of lung adenocarcinomas

BACKGROUND

The detection rate of multiple lung adenocarcinomas, which display multiple ground glass opacity nodules in the peripheral lung, is increasing because of advances in high resolution computed tomography. The genetic backgrounds of multiple nodules and the mechanisms that underlie their multicentric development are unknown. In this study, we examined single nucleotide polymorphisms (SNPs) of the cytochrome P450 19A1 gene to determine if they are associated with multiple adenocarcinomas risk.

METHODS

Fifty-one cases of multiple adenocarcinomas with lepidic growth, 62 cases of a single adenocarcinoma with lepidic growth, and 126 control cases were analyzed. Three SNPs were analyzed by using a 5' nuclease assay with TaqMan minor-groove-binder probe. The expression level of CYP19A1 in the noncancerous lung was quantified by real-time reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

A minor allele of SNP rs3764221, which is located in the CYP19A1 gene, was significantly associated with multiple adenocarcinomas risk (adjusted odds ratio = 3.06; P = 0.006). Other polymorphisms of CYP19A1 were not significantly associated with the risk of multiple adenocarcinomas. A minor allele of SNP rs3764221 was also associated with a higher level of CYP19A1 messenger RNA expression (P = 0.03).

CONCLUSIONS

SNP rs3764221 contributes to the development of multicentric adenocarcinomas in the peripheral lung by causing higher levels of CYP19A1 expression.

The combination of antitumor drugs, exemestane and erlotinib, induced resistance mechanism in H358 and A549 non-small cell lung cancer (NSCLC) cell lines

Abstract Context: Estrogens in non-small-cell lung cancer (NSCLC) are important, and their interaction with epidermal growth factor receptor (EGFR) might be crucial. Objective: This study investigates the effect of exemestane, an aromatase inhibitor, and erlotinib, an EGFR inhibitor, on human NSCLC cell lines; H23, H358 and A549. Materials and methods: A cell proliferation assay was used for measuring cell number, apoptosis assay for detecting apoptosis and necrosis and immunoblotting for beclin-1 and Bcl-2 proteins detection. An immunofluorescence assay was used for EGFR localization. A migration assay and zymography were used for cell motility and metalloproteinases (MMPs) expression, respectively. Results: Exemestane, erlotinib or their combination decreased cell proliferation and increased apoptosis. Exemestane's half maximal inhibitory concentration (IC50) was 50 μM for H23 and H358 cells and 20 μM for A549. The IC50 of erlotinib was 25 μM for all cell lines. Apoptosis increase induced by exemestane was 58.0 (H23), 186.3 (H358) and 34.7% (A549) and by erlotinib was 16.7 (H23), 65.3 (H358) and 66.3% (A549). A synergy effect was observed only in H23 cells. Noteworthy, the combination of exemestane and erlotinib decreased beclin-1 protein levels (32.3 ± 19.2%), an indicator of autophagy, in H23 cells. The combination of exemestane and erlotinib partially reversed the EGFR translocation to mitochondria and decreased MMP levels and migration. Discussion and conclusions: The benefit from a dual targeting of aromatase and EGFR seems to be regulated by NSCLC cell content. The diverse responses of cells to agents might be influenced by the dominance of certain molecular pathways.

Antiestrogen use and survival of women with non-small cell lung cancer in Manitoba, Canada

Lung cancer is the leading cause of cancer death worldwide. Sex differences in lung cancer incidence and survival are known. Female sex is an independent good prognostic factor. Estrogens appear to play a key role in lung cancer outcomes. Accordingly, antiestrogen use may also influence survival in female non-small cell lung cancer (NSCLC) patients. In this study, we compared survival among antiestrogen users and nonusers. We performed a retrospective population-based study. Using the Manitoba Cancer Registry (MCR), we identified all women diagnosed with NSCLC from 2000 to 2007. The population-based Drug Program Information Network was accessed to establish which patients received antiestrogens. Demographic data (e.g., smoking patterns, stage, histology) were gathered from the MCR and by chart review. Survival differences between antiestrogen-exposed and not exposed groups were compared using multivariable Cox regression. Two thousand three hundred twenty women fit our patient criteria, of which 156 had received antiestrogens. Exposure to antiestrogens was associated with a significantly decreased mortality in those exposed both before and after the diagnosis of NSCLC (adjusted hazard ratio, 0.42, p = 0.0006). This association remained consistent across age and stage groups. Antiestrogen use before and after the diagnosis of NSCLC is associated with decreased mortality. This supports previous evidence that estrogens may play a key role in the biology and outcomes of NSCLC and suggests a potential therapeutic use for these agents in this disease.

CYP19A1 gene polymorphisms and risk of lung cancer

Objectives

To investigate the association between polymorphisms of aromatase (encoded by the CYP19A1 gene and a key enzyme in biosynthesis of oestradiol) and the risk of lung cancer, and whether there were differences stratified by sex and smoking history.

Methods

This case–control study included consecutive, nonselected and pathologically-confirmed lung cancer patients and healthy people. Participants were classed as nonsmokers or smokers by questionnaire. Peripheral blood samples from all participants were genotyped for three single-nucleotide polymorphism (SNPs; rs727479, rs730154 and rs10046); allelic frequencies were compared across genotype and clinical records.

Results

A total of 529 patients with lung cancer and 567 age- and sex-matched controls were included. After adjustment for age, sex and smoking history, rs727479 was significantly associated with the incidence of lung cancer (for alleles AC vs AA). There was also a significant difference between patients and controls in haplotype CCA, while haplotype ACA was only significantly associated with nonsmokers and female nonsmokers.

Conclusions

Polymorphisms of CYP19A1 may be related to the increased risk of lung cancer; in particular, haplotype ACA may contribute to lung-cancer progression in nonsmokers. Further validation with larger populations is required.

Steroid sulphatase and oestrogen sulphotransferase in human non-small-cell lung carcinoma

Background:

Steroid sulphatase (STS) is one of the steroid-metabolising enzymes involved in desulphating inactive steroid sulphates and oestrogen sulphotransferase (EST) sulphates active oestrogen. The roles of both STS and EST have not been examined in oestrogen-dependent non-small-cell lung cancer (NSCLC).

Methods:

We evaluated the immunoreactivity of STS and EST in NSCLC cases using immunohistochemistry. The function of STS and EST was further demonstrated using NSCLC cell lines.

Results:

The immunoreactivity of STS and EST was detected in 49.5% and 27.8% of NSCLC cases, respectively. The immunoreactivity of STS was significantly higher in female adenocarcinoma cases. The STS-positive NSCLCs were also significantly correlated in an inversed manner with tumour size and cell proliferation and tended to be associated with better clinical outcome. However, the immunoreactivity of EST was significantly correlated with intracellular oestradiol concentration. Results of in vitro analysis demonstrated that oestrone sulphate (E1-S) induced and pregnenolone sulphate (Preg-S) inhibited the proliferation in STS-expressing cell lines. The inhibition by Preg-S was reversed by a specific progesterone receptor blocker. Simultaneous addition of E1-S and Preg-S significantly suppressed the proliferation.

Conclusion:

In NSCLC patients, STS is considered a good prognostic factor. Results of our present study also indicated the benefits of potential progesterone therapy for NSCLC patients.

The role of estrogen, progesterone and aromatase in human non-small-cell lung cancer

Lung cancer is the leading cause of cancer-related deaths in both men and women worldwide. Despite advances in treatment, patients have few effective therapeutic options and survival rates remain low. Emerging evidence suggests that the hormones estrogen and progesterone play a key role in the progression of non-small-cell lung cancer (NSCLC). The aromatase enzyme, which is responsible for a key step in estrogen biosynthesis, elicits higher levels of estrogen in lung tumors as well as in metastases compared with nonmalignant tissues. Thus, aromatase may prove to be a key predictive biomarker for treatment of NSCLC. Epidemiologic and preclinical data show estrogens play a critical role in lung tumor development and progression. Two estrogen receptors, α and β, are expressed in normal and in cancerous lung epithelium, and estrogen promotes gene transcription that stimulates cell proliferation and inhibits cell death. Furthermore, expression of both forms of estrogen receptor, progesterone receptor and aromatase in NSCLC specimens has been correlated with worse clinical outcomes. Combination therapies that include estrogen receptor downregulators and aromatase inhibitors are currently being assessed in Phase I-II clinical trials among patients with advanced NSCLC. Results will help guide future lung cancer management decisions, with a goal of achieving more effective and less toxic treatments for patients.

Identification of novel human receptor activator of nuclear factor-kB isoforms generated through alternative splicing: implications in breast cancer cell survival and migration

Introduction

The receptor activator of nuclear factor-kB (NF-kB) (RANK)/receptor activator of NF-kB ligand (RANKL) axis emerges as a key regulator of breast cancer initiation, progression and metastasis. RANK receptor is a tumor necrosis superfamily member, which upon ligand binding transduces a variety of survival, proliferation, differentiation and migration signals. The majority of these intracellular cues merge through the NF-kB transcription machinery.

Methods

TNFRSF11A (RANK) variants were identified and cloned in mammalian expression vectors. Their expression was analyzed using real time PCR on RNA from normal tissue, cell lines and breast cancer specimens. Western blot analysis and immunofluoresence stainings were used to study expression and localization of protein isoforms in a panel of breast cancer cell lines and in transfected 293T cells. Luciferase assays were employed to assess the contribution of each isoform alone or in combinations on NF-kB activation. Isoform effect on cell survival after doxorubicin treatment was analyzed through MTT assay. Wound healing and transwell assays were employed to evaluate the effect of TNFRSF11A isoforms on migration of MDA-MB-231 and 293T cells.

Results

We report the identification of three novel TNFRSF11A (RANK) variants, named TNFRSF11A_Δ9, TNFRSF11A_Δ8,9 and TNFRSF11A_Δ7,8,9 which result from the alternative splicing of exons 7 to 9. Interestingly, variant TNFRSF11A_Δ7,8,9 was found to be upregulated in breast cancer cells lines and its expression inversely correlated with tumor grade and proliferation index. TNFRSF11A_Δ7,8,9 encodes a 40-45 kDa protein, we named RANK-c, which lacks the transmembrane domain and most of the intracellular part of the wild type receptor. Furthermore, we showed that RANK-c could act as a dominant negative regulator of RANK-dependent NF-kB activation, affecting cell survival after apoptosis induction. In addition, RANK-c suppresses cell migration and represses the tumorigenic properties of invasive breast carcinoma cells.

Conclusions

In this study, we provide evidence of a complex regulatory network of RANK receptor splice variants with a role in breast cancer. We identify that the RANK-c isoform is expressed in breast cancer samples and its expression reversely correlates with histological grade. Finally, isoform RANK-c seems to have the capacity to regulate signaling through wild type RANK and moreover to inhibit cell motility and migration of breast cancer cells.

[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.

Aromatase in human lung carcinoma

Lung cancer is the leading cause of cancer mortality in both women and men worldwide but gender differences exist in their clinical and biological manifestations. In particular, among life time non-smoker, female are far more likely to develop lung carcinoma than male. Recent studies demonstrated that estrogens are synthesized in situ in both male and female lung cancers through aromatase, suggesting that sex steroid may contribute to the pathogenesis and development of lung carcinoma. In addition, human lung carcinomas have been recently demonstrated to be frequently associated with expression of estrogen receptors in both male and female patients and a lower expression of aromatase was reported to be associated with better prognosis. Preclinical studies further demonstrated that aromatase inhibitor (AI) suppressed the lung tumor growth both in vitro and in vivo. These findings all suggest a potential role of intratumoral aromatase in biological behavior of non-small cell lung cancer (NSCLC), the most common form of human lung malignancy. Therefore, AIs may become viable therapeutic options for disease management in NSCLC patients but further studies are definitely required to obtain a better understanding of the potential roles of intratumoral aromatase expression as a predictive biomarker for clinical outcome in these NSCLC patients.

Gender-related disparities in non-small cell lung cancer

Epidemiological studies clearly outline some disparities in cancer onset, progression as well as prognosis and therapeutic response between sexes. In particular, in lung cancer, the leading cause of cancer death, at least in Western countries, a gender disparity appears now to emerge, especially for non-small cell lung cancer (NSCLC). Such a disparity is apparently due to a variety of mechanisms, ranging from genetic and epigenetic differences to gender-specific lifestyle as well as to behavioral causes and, clearly, to sex hormones activity. Here we briefly recapitulate gender differences in terms of risk factors, histopathological features and pathogenetic mechanisms in NSCLC, and hypothesize that a gender-oriented pharmacology could beneficially impact on innovative therapeutic strategies.

Network-based relating pharmacological and genomic spaces for drug target identification

BACKGROUND

Identifying drug targets is a critical step in pharmacology. Drug phenotypic and chemical indexes are two important indicators in this field. However, in previous studies, the indexes were always isolated and the candidate proteins were often limited to a small subset of the human genome.

METHODOLOGY/PRINCIPAL FINDINGS

Based on the correlations observed in pharmacological and genomic spaces, we develop a computational framework, drugCIPHER, to infer drug-target interactions in a genome-wide scale. Three linear regression models are proposed, which respectively relate drug therapeutic similarity, chemical similarity and their combination to the relevance of the targets on the basis of a protein-protein interaction network. Typically, the model integrating both drug therapeutic similarity and chemical similarity, drugCIPHER-MS, achieved an area under the Receiver Operating Characteristic (ROC) curve of 0.988 in the training set and 0.935 in the test set. Based on drugCIPHER-MS, a genome-wide map of drug biological fingerprints for 726 drugs is constructed, within which unexpected drug-drug relations emerged in 501 cases, implying possible novel applications or side effects.

CONCLUSIONS/SIGNIFICANCE

Our findings demonstrate that the integration of phenotypic and chemical indexes in pharmacological space and protein-protein interactions in genomic space can not only speed the genome-wide identification of drug targets but also find new applications for the existing drugs.