Normal Human Bronchial Epithelium Cell Research Articles

The cytotoxicity of PM2.5 and its effect on the secretome of normal human bronchial epithelial cells.

Exposure to airborne fine particulate matter (PM2.5) induced various adverse health effects, such as metabolic syndrome, systemic inflammation, and respiratory disease. Many works have studied the effects of PM2.5 exposure on cells through intracellular proteomics analyses. However, changes of the extracellular proteome under PM2.5 exposure and its correlation with PM2.5-induced cytotoxicity still remain unclear. Herein, the cytotoxicity of PM2.5 on normal human bronchial epithelia cells (BEAS-2B cells) was evaluated, and the secretome profile of BEAS-2B cells before and after PM2.5 exposure was investigated. A total of 83 proteins (58 upregulated and 25 downregulated) were differentially expressed in extracellular space after PM2.5 treatment. Notably, we found that PM2.5 promoted the release of several pro-apoptotic factors and induced dysregulated secretion of extracellular matrix (ECM) constituents, showing that the abnormal extracellular environment attributed to PM2.5-induced cell damage. This study provided a secretome data for the deep understanding of the molecular mechanism underlying PM2.5-caused human bronchial epithelia cell damage.

LncRNA PKMYT1AR promotes cancer stem cell maintenance in non-small cell lung cancer via activating Wnt signaling pathway

BackgroundNon-small cell lung cancer (NSCLC) is the most common type of human lung cancers, which has diverse pathological features. Although many signaling pathways and therapeutic targets have been defined to play important roles in NSCLC, limiting efficacies have been achieved.MethodsBioinformatics methods were used to identify differential long non-coding RNA expression in NSCLC. Real-time RT-PCR experiments were used to examine the expression pattern of lncRNA PKMYT1AR, miR-485-5p. Both in vitro and in vivo functional assays were performed to investigate the functional role of PKMYT1AR/miR-485-5p/PKMYT1 axis on regulating cell proliferation, migration and tumor growth. Dual luciferase reporter assay, fluorescent in situ hybridization (FISH), immunoblot, co-immunoprecipitation experiments were used to verify the molecular mechanism.ResultHere, we identify a human-specific long non-coding RNA (lncRNA, ENST00000595422), termed PKMYT1AR (PKMYT1 associated lncRNA), that is induced in NSCLC by Yin Yang 1 (YY1) factor, especially in cancerous cell lines (H358, H1975, H1299, H1650, A549 and SPC-A1) compared to that in normal human bronchial epithelium cell line (BEAS-2B). We show that PKMYT1AR high expression correlates with worse clinical outcome, and knockdown of PKMYT1AR inhibits tumor cell proliferation, migration and xenograft tumor formation abilities. Bioinformatic analysis and a luciferase assay demonstrate that PKMYT1AR directly interacts with miR-485-5p to attenuate the inhibitory role on its downstream oncogenic factor PKMYT1 (the protein kinase, membrane-associated tyrosine/threonine 1) in NSCLC. Furthermore, we uncover that miR-485-5p is downregulated in both cancerous cell lines and peripheral blood serum isolated from NSCLC patients compared to reciprocal control groups. Consistently, forced expression of miR-485-5p inhibits the proliferation and migration abilities of tumor cells. Moreover, we provide evidence showing that PKMYT1AR targeting antisense oligonucleotide (ASO) dramatically inhibit tumor growth in vivo. Mechanistic study shows that PKMYT1AR/ miR-485-5p /PKMYT1 axis promotes cancer stem cells (CSCs) maintenance in NSCLC via inhibiting β-TrCP1 mediated ubiquitin degradation of β-catenin proteins, which in turn causes enhanced tumorigenesis.ConclusionsOur findings reveal the critical role of PKMYT1AR/miR-485-5p /PKMYT1 axis during NSCLC progression, which could be used as novel therapeutic targets in the future.

Ceramide induces MMP-9 expression through JAK2/STAT3 pathway in airway epithelium

BackgroundCeramide, a bioactive lipid, plays an essential role in the development of several pulmonary inflammatory diseases. Matrix metallopeptidase 9 (MMP-9) regulates the synthesis and degradation of extracellular matrix, and is associated with airway remodeling and tissue injury. This study was conducted to investigate the effects and underlying mechanisms of ceramide on MMP-9 expression in airway epithelium.MethodsBEAS-2B cells, normal human bronchial epithelium cell lines, were pretreated with AG490, a selective janus tyrosine kinase 2 (JAK2) inhibitor, or Stattic, a selective signal transducer and activator of transcription 3 (STAT3) inhibitor. The cells were then stimulated with C6-ceramide. The levels of MMP-9 were determined by ELISA and real-time quantitative PCR (RT-qPCR). JAK2, phosphorylated JAK2 (p-JAK2), STAT3, and phosphorylated STAT3 (p-STAT3) expression was examined by Western blotting. BALB/c mice were pretreated with AG490 or Stattic before intratracheally instillated with C6-ceramide. Pathological changes in lung tissues were examined by Hematoxylin and Eosin staining, Periodic-acid Schiff staining, and Masson’s trichrome staining. MMP-9, JAK2, p-JAK2, STAT3, and p-STAT3 expression in the lung tissues was examined by Western blotting.ResultsThe expression of MMP-9, p-JAK2 and p-STAT3 in BEAS-2B cells was significantly increased after the treatment of C6-ceramide. Furthermore, the increased expression of MMP-9 induced by C6-ceramide was inhibited by AG490 and Stattic. Similar results were obtained in the lung tissues of C6-ceramide-exposed mice which were treated with AG490 or Stattic.ConclusionsCeramide could up-regulate MMP-9 expression through the activation of the JAK2/STAT3 pathway in airway epithelium. Targeted modulation of the ceramide signaling pathway may offer a potential therapeutic approach for inhibiting MMP-9 expression. This study points to a potentially novel approach to alleviating airway remodeling in inflammatory airway diseases.

Melatonin Antagonizes Nickel-Induced Aerobic Glycolysis by Blocking ROS-Mediated HIF-1α/miR210/ISCU Axis Activation.

Nickel and its compounds, which are well-documented carcinogens, induce the Warburg effect in normal cells by stabilizing hypoxia-inducible factor 1α (HIF-1α). Melatonin has shown diverse anticancer properties for its reactive oxygen species- (ROS-) scavenging ability. Our aim was to explore how melatonin antagonized a nickel-induced increment in aerobic glycolysis. In the current work, a normal human bronchial epithelium cell line (BEAS-2B) was exposed to a series of nonlethal doses of NiCl2, with or without 1 mM melatonin. Melatonin attenuated nickel-enhanced aerobic glycolysis. The inhibition effects on aerobic glycolysis were attributed to the capability of melatonin to suppress the regulatory axis comprising HIF-1α, microRNA210 (miR210), and iron-sulfur cluster assembly scaffold protein (ISCU1/2). N-Acetylcysteine (NAC) manifested similar effects as melatonin in scavenging ROS, maintaining prolyl-hydroxylase activity, and mitigating HIF-1α transcriptional activity in nickel-exposed cells. Our results indicated that ROS generation contributed to nickel-caused HIF-1α stabilization and downstream signal activation. Melatonin could antagonize HIF-1α-controlled aerobic glycolysis through ROS scavenging.

MicroRNA-345 suppresses cell invasion and migration in non-small cell lung cancer by directly targeting YAP1.

To investigate the roles and the underlying mechanism of miR-345 in regulating non-small cell lung cancer (NSCLC) cell migration and invasion. Fifty-two pairs of NSCLC tissues and matched normal lung tissue samples were collected from NSCLC patients who had undergone surgical resection between June 2015 and August 2017 in our hospital. Human NSCLC cell lines (NCI-H460, NCI-H1299, A549 and GLC-82) and normal human bronchial epithelium cell BEAS-2B were cultured. NSCLC cell migration and invasion capacities were determined by transwell assays. The relative protein and mRNA expression level of yes-associated protein 1 (YAP1) were detected by Western blot and Quantitative Real-time polymerase chain reaction (qRT-PCR) analysis, respectively. MiR-345 was prominently downregulated in NSCLC tissue specimens. Results of transwell assays showed that miR-345 overexpression could dramatically inhibit NSCLC cell migration and invasion. Additionally, data in current study also identified YAP1 as a direct functional target of miR-345 in NSCLC cells. YAP1 expressions were negatively correlated with the miR-345 expressions in NSCLC tissue samples. Moreover, YAP1 was found to be involved in the functions of miR-345 in inhibiting NSCLC cell invasion and migration. All the above results indicated that miR-345 inhibited NSCLC cell migration and invasion by targeting YAP1, suggesting that miR-345/YAP1 axis might be a promising biomarker for NSCLC treatments.

Overexpression of circ-0067934 is associated with increased cellular proliferation and the prognosis of non-small cell lung cancer.

Previous studies have suggested that circular RNAs (circRNAs) serve crucial functions in various human diseases, including cancer. The results of the present study demonstrated that the expression levels of circ-0067934 were significantly increased in non-small cell lung cancer (NSCLC) tissues and NSCLC cells compared with that in adjacent normal tissues and a normal human bronchial epithelium cell line, as assessed using reverse transcription-quantitative polymerase chain reaction. Increased expression levels of circ-0067934 were associated with lymph node metastasis and advanced tumor stage in patients with NSCLC. Increased levels of circ-0067934 were significantly associated with the poor overall survival (OS) time of patients with NSCLC compared with low circ-0067934 expression levels, as assessed using Kaplan-Meier estimator survival curves and log-rank tests. Additionally, circ-0067934 was identified as an independent risk factor for OS time in patients with NSCLC, as assessed using univariate and multivariate Cox proportional hazards regression models. Additionally, cell proliferation and colony formation assays were employed to assess cell proliferation. The results demonstrated that the proliferative ability was significantly inhibited when circ-0067934 was knocked down in NSCLC cells. Therefore, these results indicated that circ-0067934 may be a predictive marker for the prognosis of NSCLC and a target for the treatment of the disease.

GRK5 functions as an oncogenic factor in non-small-cell lung cancer

Lung cancer is the leading cause of cancer-related deaths worldwide, and non-small-cell lung cancer (NSCLC) accounts for about 80% of all cases, which is the major subgroup of lung cancer. G protein-coupled receptor kinase 5 (GRK5) has been demonstrated to play pivotal roles in both development and progression of several pathological conditions including cancer. Here, we found that GRK5 expression was significantly increased in 539 NSCLC cancerous tissues than that in 99 normal non-cancerous tissues by immunohistochemistry analysis; we also showed intensive higher positive staining percentage in female and adenocarcinoma (ADC) NSCLC patients than that in male and squamous cell carcinoma (SCC) patients, respectively. In addition, GRK5 high expression NSCLC patients had a worse overall survival rate than the low expression patients. We provided evidence showing that both the mRNA and protein expression levels of GRK5 were increased in NSCLC cancerous cell lines (GLC-82, SPC-A-1, H520, H838, H358, A549, and H1299) comparing with that in normal human bronchial epithelium cell line (BEAS-2B), and identified many GRK5 mutations in NSCLC cancerous tissues. In addition, we found that depletion of GRK5 inhibited NSCLC cancerous cell proliferation, migration in vitro, and xenograft tumor formation in vivo. Furthermore, GRK5 knockdown promoted cell cycle arrest at G2/M phase and induced cellular apoptosis. In summary, our data reveal an oncogenic role of GRK5 in NSCLC progression, indicating that GRK5 could be used as a new therapeutic target in future.

Modelling persistent Mycoplasma pneumoniae infection of human airway epithelium.

Mycoplasma pneumoniae is a human respiratory tract pathogen causing acute and chronic airway disease states that can include long-term carriage and extrapulmonary spread. The mechanisms of persistence and migration beyond the conducting airways, however, remain poorly understood. We previously described an acute exposure model using normal human bronchial epithelium (NHBE) in air-liquid interface culture, showing that M.pneumoniae gliding motility is essential for initial colonisation and subsequent spread, including localisation to epithelial cell junctions. We extended those observations here, characterizing M.pneumoniae infection of NHBE for up to 4weeks. Colonisation of the apical surface was followed by pericellular invasion of the basolateral compartment and migration across the underlying transwell membrane. Despite fluctuations in transepithelial electrical resistance and increased NHBE cell desquamation, barrier function remained largely intact. Desquamation was accompanied by epithelial remodelling that included cytoskeletal reorganisation and development of deep furrows in the epithelium. Finally, M.pneumoniae strains S1 and M129 differed with respect to invasion and histopathology, consistent with contrasting virulence in experimentally infected mice. In summary, this study reports pericellular invasion, NHBE cytoskeletal reorganisation, and tissue remodelling with persistent infection in a human airway epithelium model, providing clear insight into the likely route for extrapulmonary spread.

Sex-Determining Region Y-box 2 Promotes Growth of Lung Squamous Cell Carcinoma and Directly Targets Cyclin D1

Sex-determining region Y-box 2 (SOX2) is an oncogene known to be amplified and overexpressed in various human malignancies, including lung squamous cell carcinoma (SCC). However, the role played by SOX2 in lung SCC development remains to be elucidated. We measured the levels of SOX2 and cyclin D1 mRNA and protein expression in lung SCC tissues and a lung SCC cell line, and found that both levels were dramatically upregulated in specimens of lung SCC tissue when compared with their expression levels in samples of adjacent nonneoplastic tissue. The lung SCC cell line also showed higher levels of SOX2 and cyclin D1 expression than a normal human bronchial epithelium cell line. After using RNA interference to knock down SOX2 expression in NCI-H520 lung SCC cells, their proliferation was reduced. Furthermore, overexpression of SOX2 promoted the proliferation of normal human bronchial epithelium cells. To further determine whether cyclin D1 was downstream target gene of SOX2, we measured the levels of cyclin D1 expression that occurred when SOX2 was knocked down or overexpressed. SOX2 knockdown significantly decreased the levels of cyclin D1 mRNA and protein expression, while SOX2 overexpression upregulated the levels of cyclin D1. We used bioinformatics data to identify potential cyclin D1 promoter binding sites for SOX2. Results of luciferase reporter assays, electrophoretic mobility shift assays, and chromatin immunoprecipitation assays confirmed that cyclin D1 was a direct target of transcription factor SOX2 in human lung SCC cells.

Acute toxicity of silver and carbon nanoaerosols to normal and cystic fibrosis human bronchial epithelial cells

Inhalation of engineered nanoparticles (NP) poses a still unknown risk. Individuals with chronic lung diseases are expected to be more vulnerable to adverse effects of NP than normal subjects, due to altered respiratory structures and functions. Realistic and dose-controlled aerosol exposures were performed using the deposition chamber NACIVT. Well-differentiated normal and cystic fibrosis (CF) human bronchial epithelia (HBE) with established air–liquid interface and the human bronchial epithelial cell line BEAS-2B were exposed to spark-generated silver and carbon nanoaerosols (20 nm diameter) at three different doses. Necrotic and apoptotic cell death, pro-inflammatory response, epithelial function and morphology were assessed within 24 h after aerosol exposure. NP exposure resulted in significantly higher necrosis in CF than normal HBE and BEAS-2B cells. Before and after NP treatment, CF HBE had higher caspase-3 activity and secreted more IL-6 and MCP-1 than normal HBE. Differentiated HBE had higher baseline secretion of IL-8 and less caspase-3 activity and MCP-1 secretion compared to BEAS-2B cells. These biomarkers increased moderately in response to NP exposure, except for MCP-1, which was reduced in HBE after AgNP treatment. No functional and structural alterations of the epithelia were observed in response to NP exposure. Significant differences between cell models suggest that more than one and fully differentiated HBE should be used in future toxicity studies of NP in vitro.Our findings support epidemiologic evidence that subjects with chronic airway diseases are more vulnerable to adverse effects of particulate air pollution. Thus, this sub-population needs to be included in nano-toxicity studies.

Combined effects of 17-DMAG and TNF on cells through a mechanism related to the NF-kappaB pathway

ObjectiveThe tumor necrosis factor (TNF) and the cellular NF-κB pathway protein IKKβ play important roles in various cellular processes such as cell proliferation, survival, differentiation, and apoptosis. A heat shock protein 90 inhibitor, 17-DMAG, can induce apoptosis of some tumor cells. This study is to determine the combined effects of 17-DMAG and TNF on malignant cells and the related mechanisms.MethodsWe have determined effects of 17-DMAG, an Hsp90 inhibitor, and TNF treatments on the small cell lung cancer cell line (MS-1), the adenocarcinoma cell line (A549), the squamous-cell carcinoma cell line (LK-2), and the normal human bronchial epithelium cell line (NuLi-1) by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrozolium bromide assay. To determine if 17-DMAG inhibit the expression of IKKβ in the normal human NuLi-1 cells, and the malignant MS-1, A549, and LK-2 cells, immunoblotting assays and luciferase assays were performed.ResultsIt was found that the combined treatments resulted in synergistic killing of malignant cells, which was confirmed by the apoptosis determination using a fluorescence microscopic assay following staining of the drug-treated cells with Hoescht 33258. The immunoblotting results indicated that the synergistic killing due to 17-DMAG and TNF treatments may be related to the decreases in IKKβ levels in the presence of 17-DMAG.ConclusionsThe results suggest that combination of 17-DMAG and TNF treatments might be useful for treating malignancies upon further study in the further.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2041198513886824

Toxicogenomic comparison of multi-wall carbon nanotubes (MWCNTs) and asbestos

Carbon nanotubes (CNTs) have specific properties, including electrical and thermal conductivity, great strength, and rigidity, that allow them to be used in many fields. However, this increasing contact with humans and the environment is also raising health and safety concerns. Thus, research on the safety of CNTs has attracted much interest, including a comparison of the toxic effects of asbestos and carbon nanotubes, due to their physical similarity of a high aspect ratio (length/diameter). Nonetheless, there has not yet been a toxicogenomic comparison. Therefore, to examine toxicogenomic effects, the 50% growth inhibition (GI(50)) concentration was determined for multi-wall carbon nanotubes (MWCNTs) and asbestos (crocidolite) and found to be approximately 0.0135 and 0.066%, respectively, in the case of 24-h treatment of normal human bronchial epithelia (NHBE) cells. Using these GI(50) concentrations, NHBE cells were then treated with MWCNTs and asbestos for 6 and 24 h, followed by a DNA microarray analysis. Among 31,647 genes, 1,201 and 1,252 were up-regulated by both asbestos and MWCNTs after 6 and 24 h of exposure, respectively. Meanwhile, 1,977 and 1,542 genes were down-regulated by both asbestos and MWNCTs after 6 and 24 h of exposure, respectively. In particular, the asbestos and MWCNTs both induced an over twofold up- and down-regulated expression of 12 mesothelioma-related genes and 22 lung cancer-related genes when compared with the negative control. Plus, the genes induced by the MWCNT exposure were expressed in the brain, lungs, epithelium, liver, and colon.

Abstract 2013: Integrative genomic studies pertaining to cigarette smoke and human lung carcinogenesis

Abstract Lung cancer is a major cause of cancer deaths worldwide. Whereas the vast majority of these neoplasms are directly attributable to cigarette abuse, the molecular mechanisms contributing to tobacco- associated pulmonary carcinogenesis are not well understood. In the present study, we utilized microarray techniques and systems biology analysis to investigate global mRNA and microRNA (miRNA) expression profiles during lung cancer progression using an in-vitro model. Four sets of cell lines were chosen to examine miRNA/mRNA signatures during lung cancer progression, including primary normal human bronchial epithelia (NHBE) as well as small airway epithelial cells (SAEC), immortalized human bronchial epithelial cells (HBEC), a lung cancer line (H1975) derived from a non-smoker, and three lung cancer lines (H1299, Calu-6 and A549) derived from smokers. Cells were cultured in normal media (NM) with or without cigarette smoke condensate (CSC), the DNA demethylating agent, 5 aza-2’ deoxycytidine (DAC), and the histone deacetylase inhibitor Depsipeptide (DP) to examine how cigarette smoke and epigenetic events may affect global mRNA and miRNA expression during pulmonary carcinogenesis. Based on global mRNA/miRNA expression clustering, primary respiratory epithelial cells, immortalized HBEC, and smoker as well as non-smoker derived lung cancer lines were readily distinguished from one another. Each cell group exhibited its own special set of miRNAs /mRNAs, which were over or under-expressed relative to primary cells. Comparison of miRNA profiles in CSC-treated vs untreated NHBE, SAEC, HBEC, A549 and Calu-6 cells revealed that cigarette smoke induces over-expression of miR-21 and miR-31. MiR-21 and miR-31 were also significantly over-expressed in smoker-derived A549 and Calu-6 lung cancer cells relative to non-smoker-derived H1975. In addition, differential gene expression profiles were observed in smoker-derived vs non-smoker derived lung cancer cells. A group of miRNAs/ mRNA were preferentially modulated by sequential DAC/DP treatment in these cultured cells. Further analysis of differentially expressed miRNAs/mRNAs observed in this model system may provide new insight regarding molecular mechanisms associated with pulmonary carcinogenesis, and reveal novel biomarkers for lung cancer diagnosis and prognosis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2013.

Decreased PITX1 homeobox gene expression in human lung cancer

The PITX1 (pituitary homeobox 1) gene has essential roles in human development and has been considered a tumor suppressor in various cancers. However, in lung cancer the role of PITX1 remains to be elucidated. In this study, we analyzed the expression of PITX1 at both mRNA and protein levels in human lung cancer. The reduced PITX1 expression was found in cancer cell lines test compared to normal human bronchial epithelia cells (HEBC) and small airway epithelia cells (SAEC) by Northern blot analysis and RT-PCR as well as Western blot analysis. In primary lung tissues, PITX1 mRNA was found to be downregulated in the majority of tumors compared with normal lung tissues. An association between the lack of PITX1 mRNA expression and higher tumor grade was observed. A tissue microarray containing 135 primary lung carcinomas was analyzed by immunohistochemistry. Eighty-four cases (62%) exhibited no expression of PITX1 and the lower expression of PITX1 was significantly linked to higher tumor stages. Additionally, PITX1 was found to be upregulated in lung cancer cell lines H2228 and H526 after they were exposed to a differentiation modifying agent 5-bromodeoxyuridine (BrdU). Since homeobox genes are known to transcriptionally regulate key cellular processes and associated with differentiation and carcinogenesis, we suggest that PITX1 might be linked to lung cancer development and progression.