epidermal-growth-factor and Adenocarcinoma-of-Lung

To investigate the mechanism of the effect of Astragalus membranaceus (A. membranaceus) on lung adenocarcinoma at the molecular level to elucidate the specific targets according to the network pharmacology approach.. The active components of A. membranaceus and their potential targets were collected from the Traditional Chinese Medicine Systems Pharmacology Database. Lung adenocarcinoma-associated genes were acquired based on GeneCards, Online Mendelian Inheritance in Man (OMIM), PharmGKB, and Therapeutic Targets databases. The PI3K/AKT signaling pathway-related genes were obtained using Reactome portal. Networks of "ingredient-target" and "ingredient-target-pathway-disease" were constructed using the Cytoscape3.6.0 software. The relationships among targets were analyzed according protein-protein interaction (PPI) network. Finally, molecular docking was applied to construct the binding conformation between active ingredients and core targets. Cell counting kit 8 (CCK8) and Western blot assays were performed to determine the mechanism of the key ingredient of A. membranaceus.. A total of 20 active components and their 329 targets, and 7,501 lung adenocarcinoma-related genes and 130 PI3K/AKT signaling pathway-related genes were obtained. According to Venn diagram and PPI network analysis, 2 mainly active ingredients, including kaempferol and quercetin, and 6 core targets, including TP53, MAPK1, EGF, AKT1, ERBB2, and EGFR, were identified. The two important active ingredients of A. membranaceus, kaempferol and quercetin, exert the therapeutic effect in lung adenocarcinoma partly by acting on the 6 core targets (TP53, MAPK1, EGF, AKT1, ERBB2, and EGFR) of PI3K/AKT signaling pathway. Expressions of potential targets in lung adenocarcinoma and normal samples were analyzed by using UALCAN portal and found that ERBB2 was overexpressed in lung adenocarcinoma tissues and upregulation of it correlated with clinicopathological characteristics. Finally, quercetin repressed viabilities of lung adenocarcinoma cells by targeting ERBB2 on PI3K/AKT signaling confirmed by CCK8 and Western blot.. Our finding unraveled that an active ingredient of A. membranaceus, quercetin, significantly inhibited the lung adenocarcinoma cells proliferation by repressing ERBB2 level and inactivating the PI3K/AKT signaling pathway.

Topics: Adenocarcinoma of Lung; Astragalus propinquus; Drugs, Chinese Herbal; Epidermal Growth Factor; ErbB Receptors; Humans; Kaempferols; Lung Neoplasms; Molecular Docking Simulation; Network Pharmacology; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Quercetin; Signal Transduction

Abnormal expression of bicellular tight junction claudins, including claudin-2 are observed during carcinogenesis in human lung adenocarcinoma. However, little is known about the role of tricellular tight junction molecule angulin-1/lipolysis-stimulated lipoprotein receptor (LSR). In the lung adenocarcinoma tissues examined in the present study, expression of claudin-2 was higher than in normal lung tissues, while angulin-1/LSR was poorly or faintly expressed. We investigated how loss of angulin-1/LSR affects the malignancy of lung adenocarcinoma cell line A549 and normal human lung epithelial (HLE) cells. The EGF receptor tyrosine kinase inhibitor AG1478 prevented the increase of claudin-2 expression induced by EGF in A549 cells. Knockdown of LSR induced expression of claudin-2 at the protein and mRNA levels and AG1478 prevented the upregulation of claudin-2 in A549 cells. Knockdown of LSR induced cell proliferation, cell migration and cell metabolism in A549 cells. Knockdown of claudin-2 inhibited the cell proliferation but did not affect the cell migration or cell metabolism of A549 cells. The TGF-β type I receptor inhibitor EW-7197 prevented the decrease of LSR and claudin-2 induced by TGF-β1 in A549 cells and 2D culture of normal HLE cells. EW-7197 prevented the increase of cell migration and cell metabolism induced by TGF-β1 in A549 cells. EW-7197 prevented the increase of epithelial permeability of FITC-4kD dextran induced by TGF-β1 in 2.5D culture of normal HLE cells. In conclusion, downregulation of angulin-1/LSR induces malignancy via EGF-dependent claudin-2 and TGF-β-dependent cell metabolism in human lung adenocarcinoma.

Topics: A549 Cells; Adenocarcinoma of Lung; Claudin-2; Down-Regulation; Epidermal Growth Factor; Humans; Lung Neoplasms; Tight Junctions; Transforming Growth Factor beta; Transforming Growth Factor beta1; Up-Regulation

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) resistance may be acquired via genotypic and/or phenotypic transformations. Herein, we report an extremely uncommon case with sequential small cell transformation and EGFR T790M mutation, in an elderly female with EGFR exon 21 L858R-mutant lung adenocarcinoma, following treatment with a first-generation EGFR-TKI.. A 67-year-old female never-smoker presented with a cough and dyspnoea of 2 months' duration. Computerised tomography revealed a 39 mm lesion in the upper lobe of the right lung with pleural effusion. Pleural fluid cytology revealed metastatic lung adenocarcinoma, and EGFR testing revealed exon 21 L858R mutation. She was started on gefitinib. After a progression-free survival of 31 months, she presented with disease progression and multiple extra-thoracic metastases. Fine needle aspiration cytology of a chest wall lesion revealed metastatic small cell carcinoma. EGFR testing on this aspirate revealed persistent L858R mutation only. In view of small cell transformation, chemotherapy (etoposide and carboplatin) was administered. After 4 months, ascitic fluid cytology revealed metastatic adenocarcinoma with persistent L858R mutation and an acquired T790M mutation (both detected on liquid biopsy as well) indicating amplification of the adenocarcinoma clone and regression of the small cell carcinoma clone. She was then initiated on osimertinib.. The index case highlights the significance of serial EGFR genotyping along with repeated tissue and/or blood sampling in the prompt detection of genetic and phenotypic resistance mechanisms to EGFR-TKIs. Furthermore, it lends evidence in support of the upfront treatment approaches targeting the heterogeneity of acquired EGFR-TKI resistance mechanisms.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Aged; Carboplatin; Carcinoma, Small Cell; Drug Resistance, Neoplasm; Epidermal Growth Factor; ErbB Receptors; Etoposide; Female; Gefitinib; Humans; Lung Neoplasms; Mutation; Protein Kinase Inhibitors

Immunotherapy based on immune checkpoint inhibitors (ICIs) have demonstrated remarkable survival benefits and gained regulatory approval in non-small cell lung cancer (NSCLC) patients without an actionable driver mutation, but currently there is no well-established standard for how to screen the most suitable population for ICIs treatment. Here, we conducted a comprehensive analysis of the somatic mutation landscape of lung adenocarcinoma (LUAD) samples. After the stepwise screening of high-frequency mutated genes, two genes with prominent significance, FAT3 and LRP1B, were finally screened out. Through further analysis, we discovered that the co-mutation of FAT3 and LRP1B was associated with an earlier age of onset and occurred more frequently in Black/African American. Furthermore, co-mutation defines a unique subgroup of lung adenocarcinoma that can increase tumor mutational burden (TMB), boost cytotoxicity and tumor immunogenicity, and facilitate lymphocyte infiltration. The results of gene set enrichment analysis (GSEA) indicated that co-mutation can influence tumorigenesis through a variety of mechanisms. More strikingly, the subset of LUAD with co-mutation of FAT3 and LRP1B exhibited significantly prolonged immunotherapy progression free survival (PFS). In summary, co-mutation of FAT3 and LRP1B is a promising useful biomarker for predicting the efficacy of immunotherapy, which can improve the clinical efficiency of practicing precision medicine in lung adenocarcinoma patients.

Topics: Adenocarcinoma of Lung; Adult; Aged; Aged, 80 and over; Antigens, Neoplasm; Area Under Curve; Biomarkers, Tumor; Cadherins; Epidermal Growth Factor; Exome Sequencing; Female; Humans; Immunotherapy; Interferon-gamma; Lymphocytes, Tumor-Infiltrating; Male; Middle Aged; Mutation; Prognosis; Receptors, LDL; Treatment Outcome; Tumor Microenvironment

The serine protease prostasin is a negative regulator of lipopolysaccharide-induced inflammation and has a role in the regulation of cellular immunity. Prostasin expression in cancer cells inhibits migration and metastasis, and reduces epithelial-mesenchymal transition. Programmed death-ligand 1 (PD-L1) is a negative regulator of the immune response and its expression in cancer cells interferes with immune surveillance. The aim of the present study was to investigate if prostasin regulates PD-L1 expression. We established sublines overexpressing various forms of prostasin as well as a subline deficient for the prostasin gene from the Calu-3 human lung cancer cells. We report here that PD-L1 expression induced by interferon-γ (IFNγ) is further enhanced in cells overexpressing the wildtype membrane-anchored prostasin. The PD-L1 protein was localized on the cell surface and released into the culture medium in extracellular vesicles (EVs) with the protease-active prostasin. The epidermal growth factor-epidermal growth factor receptor (EGF-EGFR), protein kinase C (PKC), and mitogen-activated protein kinase (MAPK) participated in the prostasin-mediated up-regulation of PD-L1 expression. A Gene Set Enrichment Analysis (GSEA) of patient lung tumors in The Cancer Genome Atlas (TCGA) database revealed that prostasin and PD-L1 regulate common signaling pathways during tumorigenesis and tumor progression.

Topics: Adenocarcinoma of Lung; B7-H1 Antigen; Cell Line, Tumor; Epidermal Growth Factor; ErbB Receptors; Extracellular Vesicles; Gene Expression Regulation, Neoplastic; Humans; Interferon-gamma; Lung Neoplasms; Mitogen-Activated Protein Kinases; Protein Kinase C; Serine Endopeptidases; Signal Transduction; Up-Regulation

Immune checkpoint inhibitors targeting programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1) have improved the survival of patients with non-small cell lung cancer (NSCLC). Still, many patients do not respond to these inhibitors. PD-L1 (CD274) expression, one of the factors that influences the efficacy of immune checkpoint inhibitors, is dynamic. Here, we studied the regulation of PD-L1 expression in NSCLC without targetable genetic alterations in EGFR, ALK, BRAF, ROS1, MET, ERBB2 and RET. Analysis of RNA sequencing data from these NSCLCs revealed that inferred IFNγ, EGFR and MAPK signaling correlated with CD274 gene expression in lung adenocarcinoma. In a representative lung adenocarcinoma cell line panel, stimulation with EGF or IFNγ increased CD274 mRNA and PD-L1 protein and membrane levels, which were further enhanced by combining EGF and IFNγ. Similarly, tumor cell PD-L1 membrane levels increased after coculture with activated peripheral blood mononuclear cells. Inhibition of the MAPK pathway, using EGFR inhibitors cetuximab and erlotinib or the MEK 1 and 2 inhibitor selumetinib, prevented EGF- and IFNγ-induced CD274 mRNA and PD-L1 protein and membrane upregulation, but had no effect on IFNγ-induced MHC-I upregulation. Interestingly, although IFNγ increases transcriptional activity of CD274, MAPK signaling also increased stabilization of CD274 mRNA. In conclusion, MAPK pathway activity plays a key role in EGF- and IFNγ-induced PD-L1 expression in lung adenocarcinoma without targetable genetic alterations and may present a target to improve the efficacy of immunotherapy. © 2019 The Authors. Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Topics: A549 Cells; Adenocarcinoma of Lung; Antineoplastic Agents; B7-H1 Antigen; Coculture Techniques; Epidermal Growth Factor; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Hepatocyte Growth Factor; Humans; Interferon-gamma; Lung Neoplasms; Mitogen-Activated Protein Kinases; Protein Kinase Inhibitors; RNA Stability; RNA, Messenger; Signal Transduction

Topics: Adenocarcinoma of Lung; Adult; Bronchoscopy; Epidermal Growth Factor; Humans; Lung; Lung Neoplasms; Male; Tomography, X-Ray Computed; Ultrasonography

Long non-coding RNAs are being increasingly recognised as important molecules involved in regulating a diverse array of biological functions. For example, many long non-coding RNAs have been associated with tumourigenesis and in this context their molecular functions often involves impacting on chromatin and transcriptional control processes. One important cellular control system that is often deregulated in cancer cells is the ERK MAP kinase pathway. Here we have investigated whether ERK pathway signaling in response to EGF stimulation, leads to changes in the production of long non-coding RNAs. We identify several different classes of EGF pathway-regulated lncRNAs. We focus on one of the inducible lincRNAs, EGF inducible long intergenic non-coding RNA 1 (EINCR1). EINCR1 is predominantly nuclear and shows delayed activation kinetics compared to other immediate-early EGF-inducible genes. In humans it is expressed in a tissue-specific manner and is mainly confined to the heart but it exhibits little evolutionary conservation. Importantly, in several cancers EINCR1 shows elevated expression levels which correlate with poor survival in lung adenocarcinoma patients. In the context of lung adenocarcinomas, EINCR1 expression is anti-correlated with the expression of several protein coding EGF-regulated genes. A potential functional connection is demonstrated as EINCR1 overexpression is shown to reduce the expression of EGF-regulated protein coding genes including FOS and FOSB.

Topics: A549 Cells; Adenocarcinoma; Adenocarcinoma of Lung; Cell Line; Cell Line, Tumor; Chromatin; Epidermal Growth Factor; Gene Expression Regulation; HEK293 Cells; Humans; Lung Neoplasms; MAP Kinase Signaling System; RNA, Long Noncoding

In a patient with previous radically treated lung adenocarcinoma, the detection of a new lung cancer raises the question whether recurrence or a second primary lung cancer is involved. Current criteria for differentiating multiple lung tumors lack a biologic and molecular basis and may lead to misclassification with impact on survival.. We report the case of a female patient with a recent diagnosis of lung adenocarcinoma and a previous lung adenocarcinoma submitted to curative surgical therapy 4 years before. As both lesions were resected, were of the same histologic subtype and presented the same immunohistochemistry profile; we decided to perform mutational analysis of the epidermal growth factor (EGFR) gene to differentiate between recurrence and second primary lung cancer.. The EGFR gene was screened for mutations in exons 18, 19, 20 and 21 using direct sequencing of polymerase chain reaction products in DNA obtained from paraffin preserved cells from both tumors.. Mutational analysis of the EGFR gene, revealed different mutations in each tumor (both on exon 19) allowing the confirmation of the diagnosis of two metachronous primary lung cancers.. In this patient, mutational analysis of the EGFR gene was superior to histologic and immunohistochemistry characterization in differentiating between recurrent lung cancer and second primary lung cancer; allowing confirmation of the diagnosis of two metachronous primary lung cancers.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; DNA Mutational Analysis; Epidermal Growth Factor; Female; Humans; Immunohistochemistry; Lung Neoplasms; Middle Aged; Mutation; Neoplasm Recurrence, Local; Neoplasms, Second Primary; Tomography, X-Ray Computed

The epidermal growth factor (EGF) plays important roles in non-small cell lung cancer (NSCLC) susceptibility and functional polymorphism in the EGF (+61A/G) gene has been linked to increased risk of NSCLC. This study aimed to evaluate the role of the EGF +61A/G polymorphism in risk of NSCLC adenocarcinoma (ADC) occurrence and survival in an Indian population.. This case- control study included 100 histopathologically confirmed NSCLC (ADC) patients and 100 healthy controls. EGF (A61G) was genotyped by AS-PCR to elucidate putative associations with clinical outcomes. The association of the polymorphism with the survival of NSCLC patients was estimated by Kaplan-Meier curves.. It was found that EGF 61AG heterozygous and GG homozygous genotype is significantly associated with increased risk of NSCLC (ADC) occurrence compared to AA genotype, [OR 2.61 (1.31-5.18) and 3.25 (1.31-8.06), RR 1.51(1.15-2.0) and 1.72 (1.08-2.73) and RD 23.2 (6.90-39.5) and 28.53(7.0-50.1) for heterozygous AG (p=0.005) and homozygous GG (p=0.009)]. Patients homozygous for the G allele exhibited a significantly poor overall survival. The median survival time for patients with EGF 61 AA, AG, and GG genotypes was 10.5, 7.4, and 7.1 months (p=0.02), respectively. NSCLC (ADC) patients with GG + AG exhibited 7.3 months median survival compared to the AA genotype (p=0.009).. The present study revealed that the EGF A61G genotype may be a novel independent prognostic marker to identify patients at higher risk of occurrence and an unfavourable clinical outcome.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Carcinoma, Non-Small-Cell Lung; Case-Control Studies; Epidermal Growth Factor; Female; Genetic Predisposition to Disease; Genotype; Humans; India; Lung Neoplasms; Male; Middle Aged; Polymorphism, Single Nucleotide; Prognosis; Risk

Tid1 (DNAJA3), a DnaJ cochaperone, may promote degradation of oncogenic kinases. Tid1 has 2 isoforms, Tid1-L and Tid1-S, that may function differently. In this study, we investigated the role of the Tid1 isoforms in regulating EGF receptor (EGFR) signaling and lung cancer progression. We found that both Tid1-L and Tid1-S expressions were reduced in patients with non-small cell lung cancer compared with normal counterparts. Tid1-L expression correlated inversely with EGFR expression. Low Tid1-L/high EGFR expression predicted poor overall survival in patients with lung adenocarcinoma. Tid1-L overexpression in lung cancer cells attenuated EGFR signaling and inhibited cell proliferation, colony formation, and tumor growth in subcutaneous and orthotropic xenograft models. Conversely, depletion of Tid1 restored EGFR signaling and increased cell proliferation and colony formation. Tid1-L, but not Tid1-S, interacted with EGFR/HSP70/HSP90 through the DnaJ domain, counteracting the EGFR regulatory function of HSP90 by causing EGFR ubiquitinylation and proteasomal degradation. Tid1-L inhibited EGFR signaling even more than the HSP90 inhibitor 17-allylamino-demethoxy geldanamycin. We concluded that Tid1-L acted as a tumor suppressor by inhibiting EGFR signaling through interaction with EGFR/HSP70/HSP90 and enhancing EGFR ubiquitinylation and degradation.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Animals; Apoptosis; Cell Line, Tumor; Cell Proliferation; Epidermal Growth Factor; ErbB Receptors; Female; Gene Expression; HSP40 Heat-Shock Proteins; HSP70 Heat-Shock Proteins; HSP90 Heat-Shock Proteins; Humans; Kaplan-Meier Estimate; Lung Neoplasms; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Middle Aged; Multivariate Analysis; Neoplasm Transplantation; Polyubiquitin; Protein Isoforms; Protein Structure, Tertiary; Proteolysis; Signal Transduction; Ubiquitination

Physiological electric field (EF) plays a pivotal role in tissue development and regeneration. In vitro, cells under direct-current electric field (dcEF) stimulation may demonstrate directional migration (electrotaxis) and long axis reorientation (electro-alignment). Although the biophysical models and biochemical signaling pathways behind cell electrotaxis have been investigated in numerous normal cells and cancer cells, the molecular signaling mechanisms in CL1 lung adenocarcinoma cells have not been identified. Two subclones of CL1 cells, the low invasive CL1-0 cells and the highly invasive CL 1-5 cells, were investigated in the present study. CL1-0 cells are non-electrotactic while the CL 1-5 cells are anodally electrotactic and have high expression level of epidermal growth factor receptor (EGFR), in this study, we investigated the generally accepted hypothesis of receptor tyrosine kinase (RTK) activation in the two cell lines under dcEF stimulation. Erbitux, a therapeutic drug containing an anti-EGFR monoclonal antibody, cetuximab, was used to investigate the EGFR signaling in the electrotaxis of CL 1-5 cells. To investigate RTK phosphorylation and intracellular signaling in the CL1 cells, large amount of cellular proteins were collected in an airtight dcEF stimulation device, which has advantages of large culture area, uniform EF distribution, easy operation, easy cell collection, no contamination, and no medium evaporation. Commercial antibody arrays and Western blotting were used to study the phosphorylation profiles of major proteins in CL1 cells under dcEF stimulation. We found that electrotaxis of CL 1-5 cells is serum independent and EGFR independent. Moreover, the phosphorylation of Akt and S6 ribosomal protein (rpS6) in dcEF-stimulated CL1 cells are different from that in EGF-stimulated cells. This result suggests that CL1 cells' response to dcEF stimulation is not through EGFR-triggered pathways. The new large-scale dcEF stimulation device developed in the present work will aid the sample preparation for protein-based experiments.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Cell Line, Tumor; Cell Movement; Cetuximab; Electric Stimulation; Electromagnetic Fields; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation; Humans; Lung Neoplasms; Phosphorylation; Proto-Oncogene Proteins c-akt; Ribosomal Protein S6; Signal Transduction

Somatic mutations in the EGFR proto-oncogene occur in ~15% of human lung adenocarcinomas and the importance of EGFR mutations for the initiation and maintenance of lung cancer is well established from mouse models and cancer therapy trials in human lung cancer patients. Recently, we identified DOK2 as a lung adenocarcinoma tumor suppressor gene. Here we show that genomic loss of DOK2 is associated with EGFR mutations in human lung adenocarcinoma, and we hypothesized that loss of DOK2 might therefore cooperate with EGFR mutations to promote lung tumorigenesis. We tested this hypothesis using genetically engineered mouse models and find that loss of Dok2 in the mouse accelerates lung tumorigenesis initiated by oncogenic EGFR, but not that initiated by mutated Kras. Moreover, we find that DOK2 participates in a negative feedback loop that opposes mutated EGFR; EGFR mutation leads to recruitment of DOK2 to EGFR and DOK2-mediated inhibition of downstream activation of RAS. These data identify DOK2 as a tumor suppressor in EGFR-mutant lung adenocarcinoma.

Topics: Adaptor Proteins, Signal Transducing; Adenocarcinoma; Adenocarcinoma of Lung; Animals; Carcinogenesis; Cell Line; Epidermal Growth Factor; ErbB Receptors; Extracellular Signal-Regulated MAP Kinases; Gene Knockout Techniques; Genomics; Humans; Lung Neoplasms; Male; Mice; Mice, Transgenic; Mutation; Phosphoproteins; Proto-Oncogene Mas; ras Proteins; Tumor Suppressor Proteins

Sphingosine-1-phosphate (S1P) regulates a wide array of biological functions. However, the role of S1P signaling in tumorigenesis remains to be elucidated. In this study, we show that S1P receptor subtype 3 (S1P₃) is markedly up-regulated in a subset of lung adenocarcinoma cells compared to normal lung epithelial cells. Specific knockdown of S1P₃ receptors inhibits proliferation and anchorage-independent growth of lung adenocarcinoma cells. Mechanistically, we demonstrate that S1P₃ signaling increases epidermal growth factor receptor (EGFR) expression via the Rho kinase (ROCK) pathway in lung adenocarcinoma cells. Nuclear run-off analysis indicates that S1P/S1P₃ signaling transcriptionally increases EGFR expression. Knockdown of S1P₃ receptors diminishes the S1P-stimulated EGFR expression in lung adenocarcinoma cells. Moreover, S1P treatment greatly enhances EGF-stimulated colony formation, proliferation and invasion of lung adenocarcinoma cells. Together, these results suggest that the enhanced S1P₃-EGFR signaling axis may contribute to the tumorigenesis or progression of lung adenocarcinomas.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Animals; Carcinoma, Lewis Lung; Cell Line, Tumor; Cell Movement; Cell Proliferation; Epidermal Growth Factor; ErbB Receptors; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Lysophospholipids; Mice; Neoplasm Invasiveness; Receptors, Lysosphingolipid; rho-Associated Kinases; RNA Interference; RNA, Messenger; Signal Transduction; Sphingosine; Sphingosine-1-Phosphate Receptors; Time Factors; Transcriptional Activation; Transfection; Up-Regulation

In human adenocarcinoma, claudin-2 expression is higher than that in normal lung tissue, but the regulatory mechanism of its expression has not been clarified. In human adenocarcinoma A549 cells, claudin-2 level time-dependently increased under the control conditions. In contrast, claudin-1 expression remained constant for 24h. The concentration of epidermal growth factor (EGF) in medium time-dependently increased, which was inhibited by matrix metalloproteinase (MMP) inhibitor II, an inhibitor of MMP-1, 3, 7, and 9. MMP inhibitor II decreased claudin-2 and phosphorylated ERK1/2 (p-ERK1/2) levels, which were recovered by EGF. Both claudin-2 and p-ERK1/2 levels were decreased by EGF neutralizing antibody, EGF receptor (EGFR) siRNA, AG1478, an inhibitor of EGFR, U0126, an inhibitor of MEK, and the exogenous expression of dominant negative-MEK. These results suggest that EGF is secreted from A549 cells by MMP and increases claudin-2 expression mediated via the activation of an EGFR/MEK/ERK pathway. The inhibition of the signaling pathway decreased phosphorylated c-Fos and nuclear c-Fos levels. The introduction of c-Fos siRNA decreased claudin-2 level without affecting claudin-1. The promoter activity of human claudin-2 was decreased by AG1478 and U0126. Furthermore, the activity was decreased by the deletion or mutation of the AP-1 binding site of claudin-2 promoter. Chromatin immunoprecipitation and avidin-biotin conjugated DNA assays showed that c-Fos binds to the AP-1 binding site. We suggest that a secreted EGF up-regulates the transcriptional activity of claudin-2 mediated by the activation of an EGFR/MEK/ERK/c-Fos pathway in A549 cells.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Binding Sites; Butadienes; Cell Line, Tumor; Claudins; Epidermal Growth Factor; ErbB Receptors; Female; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Male; MAP Kinase Signaling System; Nitriles; Promoter Regions, Genetic; Protease Inhibitors; Protein Binding; Proto-Oncogene Proteins c-fos; Quinazolines; RNA, Messenger; RNA, Small Interfering; Transcription Factor AP-1; Tyrphostins

Chemotherapy drug resistance is a major obstacle in the treatment of cancer. It can result from an increase in levels of cellular drug efflux pumps, such as P-glycoprotein (P-gp). Lapatinib, a growth factor receptor tyrosine kinase inhibitor, is currently in clinical trials for treatment of breast cancer. We examined the impact of co-incubation of chemotherapy drugs in combination with lapatinib in P-gp over-expressing drug resistant cells. Unexpectedly, lapatinib treatment, at clinically relevant concentrations, increased levels of the P-gp drug transporter in a dose- and time-responsive manner. Conversely, exposure to the epidermal growth factor (EGF), an endogenous growth factor receptor ligand, resulted in a decrease in P-gp expression. Despite the lapatinib-induced alteration in P-gp expression, use of accumulation, efflux and toxicity assays demonstrated that the induced alteration in P-gp expression by lapatinib had little direct impact on drug resistance.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Antineoplastic Combined Chemotherapy Protocols; ATP Binding Cassette Transporter, Subfamily B, Member 1; Carcinoma, Squamous Cell; Cell Line, Tumor; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Humans; Lapatinib; Lung Neoplasms; Male; Middle Aged; Protein Kinase Inhibitors; Quinazolines; Time Factors

Estrogens contribute to the pathogenesis of female lung cancer and function mainly through estrogen receptor-β (ERβ). However, the way in which ERβ expression is regulated in lung cancer cells remains to be explored. We have found that signal transducer and activator of transcription 3 (Stat3) activation up-regulates ERβ expression in PC14PE6/AS2 lung cancer cells in a preliminary Affymetrix oligonucleotide array study, and we sought to confirm the findings. In this study, we show that IL-6 induced ERβ mRNA and protein expression in lung cancer cells. The induction of ERβ in response to IL-6 was abolished by Janus kinase 2 inhibitor-AG490, dominant-negative mutant of Stat3, and Stat3-targeting short interfering RNA. The luciferase reporter assay and chromatin immunoprecipitation assay confirmed that IL-6-activated Stat3 binds to the ERβ promoter. Besides the Janus kinase 2/Stat3 pathway, the MEK/Erk pathway contributes to ERβ up-regulation induced by IL-6; however, the phosphoinositide 3'-kinase/Akt pathway does not. We also found that epidermal growth factor (EGF) stimulation or L858R mutation in EGF receptor (EGFR) induced Stat3 activation as well as ERβ expression in lung cancer cells. Inhibiting Stat3 activity by pharmacological or genetic approaches reduced EGF- and L858R mutant EGFR-induced ERβ expression, indicating that Stat3 activation is required for EGFR signaling-mediated ERβ up-regulation. Silencing ERβ decreased cell proliferation in lung cancer cells that overexpress L858R mutant EGFR. In conclusion, we have identified that Stat3 activation is essential for ERβ induction by IL-6, EGF, and the presence of EGFR mutation. The findings shed light on new therapeutic targets for female lung cancer, especially for those with EGFR mutations.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Cell Line, Tumor; Cell Proliferation; Epidermal Growth Factor; ErbB Receptors; Estrogen Receptor beta; Female; Gene Expression Regulation, Neoplastic; Humans; Interleukin-6; Lung Neoplasms; MAP Kinase Signaling System; Mutation, Missense; Neoplasms, Hormone-Dependent; Phosphorylation; Protein Binding; RNA Stability; STAT3 Transcription Factor; Transcription, Genetic; Up-Regulation

The epidermal growth factor receptor (EGFR) can be activated by several growth factors within the tumor microenvironment, and it can activate several signaling pathways. For tumor development, these EGFR-related signaling pathways may converge on several common nuclear transcription factors, one such transcription factor being STAT5. STAT5 plays an important role in the oncogenic signal transduction pathway in non-small cell lung cancer. In this study, we examined whether the epidermal growth factor (EGF) can stimulate cyclooxygenase-2 (COX-2) expression in human lung adeno-carcinoma A549 cells transfected with or without STAT5 siRNA or dominant-negative (DN)-STAT5, and identified the pathways involved in this response. We found that STAT5 siRNA significantly reduced EGF-induced COX-2 expression, and STAT5 phosphorylation. STAT5 phosphorylation predominantly mediates EGF-induced COX-2 promoter activity. STAT5 siRNA was found to inhibit COX-2 expression in resting A549 cells despite the absence of detectable activated phosphorylated STAT5. Using an adenoviral system, we expressed DN-STAT5 in human lung adenocarcinoma A549 cells in order to broaden the investigation and to determine the role of STAT5 in EGF-mediated COX-2 gene expression. The overexpression of DN-STAT5 significantly inhibited EGF-induced COX-2 expression, and we found that EGF induced the tyrosine phosphorylation of STAT5 and up- regulated COX-2 expression. DN-STAT5 also blocked COX-2 promoter activity. Our results demonstrate that EGF stimulates COX-2 expression in human lung adenocarcinoma A549 cells via the activation of the STAT5 pathway and that COX-2 expression may be independent of phosphorylated STAT5 in A549 cells in vitro.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Cell Line, Tumor; Cyclooxygenase 2; DNA-Binding Proteins; Epidermal Growth Factor; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Phosphorylation; Promoter Regions, Genetic; RNA, Small Interfering; Signal Transduction; STAT5 Transcription Factor

Lung cancer is one of the leading causes of death in the world. Some tumor events are attributed to an important group of molecules (cadherins and integrins). We evaluated the interactions of cell adhesion molecules in cell lines from lung cancer. Two lung cancer cell lines were nonmetastatic (H358 and H441) and two were metastatic (H1299 and H292). All cell lines were treated with epidermal growth factor (EGF), and Western blot analysis was performed to assess the interactions between these proteins. The bronchoalveolar cells H358 showed the three analyzed proteins: E-cadherin, β-catenin, and p120 catenin. The adenocarcinoma cells H441 did not present p120 catenin, and carcinoma cells did not show E-cadherin (H1299) or p120 catenin (H292). FAK (pTyr925) was dephosphorylated in adenocarcinoma cells H441, absent in carcinoma cells H1299, and upregulated in the other carcinoma cells H292. p130Cas showed no difference when the cell lines were treated with EGF for 30 min; it was absent in the metastatic carcinoma cells H1299. Paxillin was dephosphorylated in adenocarcinoma cells H441 and also absent in other metastatic carcinoma cells H292. Vinculin showed the same results, and talin was downregulated in adenocarcinoma cells H441 when the cells were treated with EGF. Rap1 was downregulated and PYK2 was upregulated in the same cell line. Our data help to comprehend the mechanism involved in cell migration to the blood and metastasis generation. In conclusion, the expression patterns of cell-cell adhesion were not affected by EGF treatment but it affected cell-extracellular matrix adhesion.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; beta Catenin; Cadherins; Carcinoma, Non-Small-Cell Lung; Catenins; Cell Adhesion Molecules; Cell Line, Tumor; Crk-Associated Substrate Protein; Delta Catenin; Epidermal Growth Factor; Focal Adhesion Kinase 1; Humans; Lung Neoplasms; Paxillin; rap1 GTP-Binding Proteins; Talin; Vinculin

Ion channels involved in the migration of tumor cells that is required for their invasion and metastasis. In this paper, we describe the interaction of TRPM7 channel and epidermal growth factor (EGF), an important player in cancer development in the migration of lung cancer cells. The TRPM7 currents in A549 cells were first characterized by means of electrophysiology, pharmacology and RNA interference. Removing Ca(2+) from the extracellular solution not only potentiated a large inward current, but also abolished the outward rectification. 200μM 2-APB inhibited the outward and the inward TRPM7 currents and at the same time restored the property of outward rectification. EGF greatly enhanced the migration of A549 cells, and also markedly up-regulated the membrane protein expression of TRPM7 and the amplitude of TRPM7 currents. Depressing the function of TRPM7 with RNA interference or pharmacological agents not only reversed the EGF-enhanced migration of A549 cells but also inhibited the basal migration of A549 cells in the absence of EGF. Thus it seems that TRPM7 plays a pivotal role in the migration of A549 cells induced by EGF and thus could be a potential therapeutic target in lung cancers.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Blotting, Western; Calcium; Cell Line, Tumor; Cell Movement; Epidermal Growth Factor; Humans; Lung Neoplasms; Membrane Potentials; Patch-Clamp Techniques; Protein Serine-Threonine Kinases; RNA, Small Interfering; TRPM Cation Channels; Up-Regulation