Healthy Human Bronchial Epithelial Cells Research Articles

Cigarette smoking induces lung cancer tumorigenesis via upregulation of the WNT/β-catenin signaling pathway

Lung cancer has the highest mortality rate compared to any other cancer worldwide, and cigarette smoking is one of the major etiological factors. How cigarette smoke (CS) induces tumorigenesis in healthy cells is still not completely understood. In this study, we treated healthy human bronchial epithelial cells (16HBE14o) with 1 % cigarette smoke extract (CSE) for one week. The CSE exposed cells showed upregulation of WNT/β-catenin pathway genes like WNT3, DLV3, AXIN and β-catenin, 30 oncology proteins were found to be upregulated after CSE treatment. Further, we explored whether the role of extracellular vesicles (EVs) obtained from CSE exposed cells can induce tumorigenesis. We observed that CSE EVs induced migration of healthy 16HBE14o cells by upregulation of various oncology proteins in recipient cells like AXL, EGFR, DKK1, ENG, FGF2, ICAM1, HMOX1, HIF1a, SERPINE1, SNAIL, HGFR, PLAU which are related to WNT signaling, epithelial mesenchymal transition (EMT) and Inflammation, whereas inflammatory marker, GAL-3 and EMT marker, VIM were downregulated. Moreover, β-catenin RNA was found in CSE EVs, upon treatment of these EVs to healthy cells, the β-catenin gene level was decreased in recipient cells compared to healthy 16HBE14o cells, indicating the utilisation of β-catenin RNA in healthy cells. Overall, our study suggests that CS treatment can induce tumorigenesis of healthy cells by upregulating WNT/β-catenin signaling in vitro and human lung cancer patients. Therefore targeting the WNT/β-catenin signaling pathway is involved in tumorigenesis inhibition of this pathway could be a potential therapeutic approach for cigarette smoke induced lung cancer.

Extracellular Vesicles Released from Cancer Cells Promote Tumorigenesis by Inducing Epithelial to Mesenchymal Transition via β-Catenin Signaling

Lung cancer is the leading cause of cancer-related deaths globally, in part due to a lack of early diagnostic tools and effective pharmacological interventions. Extracellular vesicles (EVs) are lipid-based membrane-bound particles released from all living cells in both physiological and pathological states. To understand the effects of lung-cancer-derived EVs on healthy cells, we isolated and characterized EVs derived from A549 lung adenocarcinoma cells and transferred them to healthy human bronchial epithelial cells (16HBe14o). We found that A549-derived EVs carry oncogenic proteins involved in the pathway of epithelial to mesenchymal transition (EMT) that are regulated by β-catenin. The exposure of 16HBe14o cells to A549-derived EVs resulted in a significant increase in cell proliferation, migration, and invasion via upregulating EMT markers such as E-Cadherin, Snail, and Vimentin and cell adhesion molecules such as CEACAM-5, ICAM-1, and VCAM-1, with concomitant downregulation of EpCAM. Our study suggests a role for cancer-cell-derived EVs to induce tumorigenesis in adjacent healthy cells by promoting EMT via β-catenin signaling.

PAK1 as a Potential Therapeutic Target in Male Smokers with EGFR-Mutant Non-Small Cell Lung Cancer.

P21-activated kinases (PAKs) are serine/threonine protein kinases that contribute to several cellular processes. Here, we aimed to determine the prognostic value of PAK1 and its correlation with the clinicopathological characteristics and five-year survival rates in patients with non-small cell lung cancer (NSCLC). We evaluated PAK1 mRNA and protein expression in NSCLC cells and resected tumor specimens, as well as in healthy human bronchial epithelial cells and adjacent healthy lung tissues, respectively, for effective comparison. Immunohistochemical tissue microarray analysis of 201 NSCLC specimens showed the correlation of PAK1 expression with clinicopathological characteristics. The mRNA and protein expression of PAK1 were 2.9- and 4.3-fold higher in six of seven NSCLC cell types and human tumors (both, p < 0.001) than in healthy human bronchial epithelial BEAS-2B cells and adjacent healthy lung tissues, respectively. Decreased survival was significantly associated with PAK1 overexpression in the entire cohort (χ2 = 8.48, p = 0.0036), men (χ2 = 17.1, p < 0.0001), and current and former smokers (χ2 = 19.2, p < 0.0001). Notably, epidermal growth factor receptor (EGFR) mutation-positive lung cancer patients with high PAK1 expression showed higher mortality rates than those with low PAK1 expression (91.3% vs. 62.5%, p = 0.02). Therefore, PAK1 overexpression could serve as a molecular target for the treatment of EGFR mutation-positive lung cancer, especially among male patients and current/former smokers.

Effects of vitamin D on inflammatory and oxidative stress responses of human bronchial epithelial cells exposed to particulate matter.

BackgroundParticulate matter (PM) pollutant exposure, which induces oxidative stress and inflammation, and vitamin D insufficiency, which compromises immune regulation, are detrimental in asthma.ObjectivesMechanistic cell culture experiments were undertaken to ascertain whether vitamin D abrogates PM-induced inflammatory responses of human bronchial epithelial cells (HBECs) through enhancement of antioxidant pathways.MethodsTranscriptome analysis, PCR and ELISA were undertaken to delineate markers of inflammation and oxidative stress; with comparison of expression in primary HBECs from healthy and asthmatic donors cultured with reference urban PM in the presence/absence of vitamin D.ResultsTranscriptome analysis identified over 500 genes significantly perturbed by PM-stimulation, including multiple pro-inflammatory cytokines. Vitamin D altered expression of a subset of these PM-induced genes, including suppressing IL6. Addition of vitamin D suppressed PM-stimulated IL-6 production, although to significantly greater extent in healthy versus asthmatic donor cultures. Vitamin D also differentially affected PM-stimulated GM-CSF, with suppression in healthy HBECs and enhancement in asthmatic cultures. Vitamin D increased HBEC expression of the antioxidant pathway gene G6PD, increased the ratio of reduced to oxidised glutathione, and in PM-stimulated cultures decreased the formation of 8-isoprostane. Pre-treatment with vitamin D decreased CXCL8 and further decreased IL-6 production in PM-stimulated cultures, an effect abrogated by inhibition of G6PD with DHEA, supporting a role for this pathway in the anti-inflammatory actions of vitamin D.ConclusionsIn a study using HBECs from 18 donors, vitamin D enhanced HBEC antioxidant responses and modulated the immune response to PM, suggesting that vitamin D may protect the airways from pathological pollution-induced inflammation.

Molecularly Selective Regulation of Delivery Fluxes by Employing Supramolecular Interactions in Layer-by-Layer Films.

The molecularly selective regulation of molecular fluxes in a biomaterial that delivers multiple chemical species simultaneously is still beyond the reach of materials scientists. A delivery material was developed by means of the layer-by-layer (LbL) technique. This material discriminatively regulates the delivery flux of bioactive small molecules, as represented by a peptide containing the RGD fragment and the chemotherapy drug doxorubicin (DOX). Molecularly selective flux regulations in LbL films are realized through fast, reversible supramolecular interactions between cyclodextrin and its guests. The mechanism underlining the delivery strategy is that supramolecular interactions promote molecular loading and slow down diffusion-dependent release. In a preliminary survey of materials parameters, a maximum difference in cell viability between healthy human bronchial epithelial cells and cancer cells (A549) was realized.

Combination of Silver Nanoparticles and Curcumin Nanoparticles for Enhanced Anti-biofilm Activities.

Biofilm tolerance has become a serious clinical concern in the treatment of nosocomial pneumonia owing to the resistance to various antibiotics. There is an urgent need to develop alternative antimicrobial agents or combination drug therapies that are effective via different mechanisms. Silver nanoparticles (AgNPs) have been developed as an anti-biofilm agent for the treatment of infections associated with the use of mechanical ventilations, such as endotracheal intubation. Meanwhile curcumin, a phenolic plant extract, has displayed natural anti-biofilm properties through the inhibition of bacterial quorum sensing systems. The aim of this study was to investigate the possible synergistic/additive interactions of AgNPs and curcumin nanoparticles (Cur-NPs) against both Gram-negative (Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) microorganisms. The combination of AgNPs and Cur-NPs (termed Cur-SNPs) at 100 μg/mL disrupted 50% of established bacterial biofilms (formed on microtiter plates). However, further increase in the concentration of Cur-SNPs failed to effectively eliminate the biofilms. To achieve the same effect, at least 500 μg/mL Cur-NP alone was needed. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) revealed that combination therapy (Cur-SNPs) was the most potent to eradicate preformed biofilm compared to monodrug therapy. These agents are also nontoxic to healthy human bronchial epithelial cells (BEAS2B).

Multiwalled carbon nanotubes induce altered morphology and loss of barrier function in human bronchial epithelium at noncytotoxic doses.

Multiwalled carbon nanotubes (MWCNTs) have seen increasing application in consumer products over the past decade, resulting in an increasing risk of human exposure. While numerous toxicological studies have been performed using acute high doses of various carbonaceous nanomaterials, the effects of longer-term, low doses of MWCNTs remain relatively unexplored. This study examined bronchoscopy-derived healthy human bronchial epithelial cells exposed in submerged culture to noncytotoxic doses of MWCNTs over 7 days. Under these conditions, doses as low as 3 μg/mL caused altered cell morphology, superficially resembling fibroblasts. Electrical impedance of the epithelial monolayer was greatly reduced following MWCNT exposure. However, Western blot and polymerase chain reaction showed no elevated expression of the fibroblast markers, vimentin, α-smooth muscle actin, or fibronectin, indicating that a mechanism other than epithelial–mesenchymal transition may be responsible for the changes. Phalloidin and tubulin immunostaining showed disruption of the cytoskeleton, and confocal imaging showed a reduction of the tight junction proteins, zona occludens 1 and occludin. We propose that MWCNTs interfere with the cytoskeleton of the lung epithelium, which can result in a harmful reduction in barrier function over time, even at noncytotoxic doses.