Lung Epithelial BEAS-2B Cells Research Articles

CircFBXW7 Inhibits Proliferation, Migration, and Invasion of Nonsmall Cell Lung Cancer Cells by Regulating miR-492.

Background CircFBXW7 has been determined to be involved in various cancers; however, its role in nonsmall cell lung cancer (NSCLC) remains unclear. This study examined the function and potential mechanism of circFBXW7 in NSCLC. Methods The structure of circFBXW7 was verified via RT-PCR and Sanger sequencing. The expression of circFBXW7 in NSCLC was determined by qRT-PCR. The effect of circFBXW7 overexpression on the proliferation, migration, and invasion of NSCLC cells was examined by CCK-8 and Transwell assays. Furthermore, a circFBXW7-miRNA network was established to explore their interaction. Predicted miRNA was determined by qRT-PCR. Moreover, the miRNA mimics were synthesized, wherein its effect on proliferation, migration, and invasion of NSCLC cells overexpressed circFBXW7 was assessed. Results The circularity of circFBXW7 was verified. The expression of circFBXW7 was found to be downregulated in NSCLC cells compared with that in normal human lung epithelial BEAS-2B cells. Overexpression of circFBXW7 reduced cell proliferation, migration, and invasion. Furthermore, according to the circFBXW7-miRNA network prediction and qRT-PCR validation, miR-492 was identified to be the target of circFBXW7. The inhibitory effect of circFBXW7 overexpression on cell proliferation, migration, and invasion was reversed by miR-492 mimics. Conclusion CircFBXW7 is downregulated in NSCLC. CircFBXW7 inhibits NSCLC cells proliferation, migration, and invasion by regulating miR-492.

Effects of ZnO nanoparticles on proliferation and apoptosis of human lung epithelial BEAS-2B cells

To investigate the effects of ZnO nanoparticles (ZnO NPs) on proliferation and apoptosis of human lung epithelial cells BEAS-2B and its molecular mechanisms. BEAS-2B cells were treated with ZnO NPs at concentrations of 3, 6 and 12 μg/ml for 12 h and 24 h, the control group was not treated with ZnO NPs, each with 3 replicate wells. Cell viability was detected by CCK-8 method, and the half lethal concentration (IC50) was analyzed. Then, the BEAS-2B cells were treated with ZnO NPs at selected concentrations of 3 and 6 μg/ml for 24 h respectively,each group was set with 3 replicate. Cell morphology was observed under inverted microscope. The morphology of cell nuclei was observed by Hochest33342 staining. The morphology of apoptosis was observed by AO staining and scanning electron microscopy. Cell cycle progression, cell apoptosis rate and the level of reactive oxygen species(ROS)were detected by flow cytometry. Western blot was used to detect the expression levels of Bcl-2 and Bax protein. Compared with the control group, the cell viability of cells treated with ZnO NPs were decreased significantly(P＜0.01), and the IC50 was 6.13 μg/ml at 24 h of drug treatment. After the cells were treated with ZnO NPs for 24 h, the levels of ROS were increased significantly(P＜0.05, P＜0.01)in 3 μg/ml, 6 μg/ml groups. The cell cycle was arrested at G2/M phase, chromatin condensation and apoptotic bodies were induced, apoptosis rate was increased significantly(P＜0.01) in 6 μg/ml group. The expression of Bcl-2 was decreased(P＜0.05), and the expression of Bax was increased (P＜0.05) in cells treated with 6 μg/ml ZnO NPs for 24 h. ZnO NPs induced ROS accumulation, blocked progress of cell cycle and induced cell apoptosis in BEAS-2B cells.

P07-42 Potential toxicity of polystyrene microplastics with different particle size and surface charge in human lung epithelial BEAS-2B cells

P07-42 Potential toxicity of polystyrene microplastics with different particle size and surface charge in human lung epithelial BEAS-2B cells

Ejiao ameliorates lipopolysaccharide-induced pulmonary inflammation via inhibition of NFκB regulating NLRP3 inflammasome and mitochondrial ROS.

There is no effective treatment for acute lung injury (ALI) at present. Some studies have reported the anti-inflammatory effect of Ejiao, but no study has addressed the underlying action mechanism. In this study, the CCK8 assay displayed Ejiao had a protective effect against LPS-elicited inflammatory lung epithelial Beas 2B cells (LILEB 2B cells). Beas 2B cells treated with LPS and Ejiao were challenged with NFκB inhibitor Bay11-7082 and ROS scavenger N-acetyl cysteine (NAC) alone and in combination. The results of qRT-PCR, Western blotting and fluorescence labeling experiments using Bay11-7082 and NAC demonstrated Ejiao could significantly decrease the expression of p-p65 and p-IκBα in NFκB signaling pathway and its downstream NLRP3, ASC, Caspase-1 and IL-1β related to pyroptosis of LILEB 2B cells. Moreover, Ejiao reduced the production of mitochondrial ROS and reversed the change of mitochondrial membrane potential of LILEB 2B cells. Then, HE staining demonstrated Ejiao had a protective effect against the LPS-elicited ALI mouse model (LAMM). Ejiao also dramatically decreased the cell amount and the overall protein concentration of bronchoalveolar lavage fluid in LAMM. Immunohistochemical staining showed Ejiao remarkably reduced the expression of p-p65 and p-IκBα in NFκB signaling pathway and its downstream NLRP3, ASC, Caspase-1 and IL-1β. The ELISA of IL-1β revealed Ejiao could dose-dependably decrease the concentration of IL-1β in lung tissues, serum and BALF of LAMM. Finally, fluorescence labeling demonstrated Ejiao significantly reduced the mitochondrial ROS generation in the lung tissue of LAMM. This finding may afford a novel strategy for the precaution and therapy of ALI.

Disposable Puff Bar Electronic Cigarettes: Chemical Composition and Toxicity of E-liquids and a Synthetic Coolant.

The popularity of disposable fourth-generation electronic cigarettes (ECs) among young adults and adolescents has been increasing since the ban on flavored cartridge EC products such as JUUL. Although the constituents and toxicity of some cartridge-based fourth-generation ECs, such as JUUL, have been studied, limited data exist for other disposable ECs such as Puff. The purpose of this study was to determine flavor chemicals, synthetic coolants, and nicotine concentrations in 16 disposable Puff devices, evaluate the cytotoxicity of the different flavors from the Puff brand using in vitro assays, and investigate the health risks of synthetic coolants in EC products. Gas chromatography/mass spectrometry was used to identify and quantify chemicals in Puff EC fluids. One hundred and twenty-six flavor chemicals were identified in Puff fluids, and 16 were >1 mg/mL. WS-23 (2-isopropyl-N,2,3-trimethylbutyramide) was present in all products, and concentrations ranged from 0.8 to 45.1 mg/mL. WS-3 (N-ethyl-p-menthane-3-carboxamide) concentrations ranged from 1.5 to 16.4 mg/mL in 6/16 products. Nicotine concentrations ranged from 40.6 to 52.4 (average 44.8 mg/mL). All unvaped fluids were cytotoxic at dilutions between 0.1 and 10% in the MTT and neutral red uptake assays when tested with BEAS-2B lung epithelial cells. The cytotoxicity of Puff fluids was highly correlated with total chemical concentrations, nicotine, WS-23, both synthetic coolants, and synthetic coolants plus ethyl maltol. Lower concentrations of WS-23 than those in the fluids adversely affected cell growth and morphology. Concentrations of synthetic coolants exceeded levels used in consumer products. The margin of exposure data showed that WS-3 and WS-23 concentrations were high enough in Puff products to present a health hazard. Our study demonstrates that disposable Puff ECs have high levels of cytotoxic chemicals. The data support the regulation of flavor chemicals and synthetic coolants in ECs to limit potentially harmful health effects.

Tobacco-specific nitrosamine 1-(N-methyl-N-nitrosamino)-1-(3-pyridinyl)-4-butanal (NNA) causes DNA damage and impaired replication/transcription in human lung cells.

Thirdhand smoke (THS) is a newly described health hazard composed of toxicants, mutagens and carcinogens, including nicotine-derived tobacco specific nitrosamines (TSNAs), one of which is 1-(N-methyl-N-nitrosamino)-1-(3-pyridinyl)-4-butanal (NNA). Although TSNAs are generally potent carcinogens, the risk of NNA, which is specific to THS, is poorly understood. We recently reported that THS exposure-induced adverse impact on DNA replication and transcription with implications in the development of cancer and other diseases. Here, we investigated the role of NNA in THS exposure-induced harmful effects on fundamental cellular processes. We exposed cultured human lung epithelial BEAS-2B cells to NNA. The formation of DNA base damages was assessed by Long Amplicon QPCR (LA-QPCR); DNA double-strand breaks (DSBs) and NNA effects on replication and transcription by immunofluorescence (IF); and genomic instability by micronuclei (MN) formation. We found increased accumulation of oxidative DNA damage and DSBs as well as activation of DNA damage response pathway, after exposure of cells to NNA. Impaired S phase progression was also evident. Consistent with these results, we found increased MN formation, a marker of genomic instability, in NNA-exposed cells. Furthermore, ongoing RNA synthesis was significantly reduced by NNA exposure, however, RNA synthesis resumed fully after a 24h recovery period only in wild-type cells but not in those deficient in transcription-coupled nucleotide excision repair (TC-NER). Importantly, these cellular effects are common with the THS-exposure induced effects. Our findings suggest that NNA in THS could be a contributing factor for THS exposure-induced adverse health effect.

The downregulation of miR-129-5p relieves the inflammatory response in acute respiratory distress syndrome by regulating PPARγ-mediated autophagy

BackgroundThe peroxisome proliferator-activated receptor γ (PPARγ) promotes autophagy and regulates the inflammatory response. However, the effects of the PPARγ on inflammation in acute respiratory distress syndrome (ARDS) are unclear. This study sought to explore the mechanism by which the downregulation of microRNA-129-5p (miR-129-5p) attenuates the inflammatory response in ARDS patients by regulating PPARγ-mediated autophagy.MethodsLipopolysaccharide (LPS) was used to establish an acute lung injury (ALI) mice model to simulate ARDS. GW9662 and pioglitazone were applied to inhibit and activate the PPARγ, respectively. Enzyme-linked immunoassays were used to detect inflammatory cytokines. The expressions of miR-129-5p, the PPARγ, and the autophagy-marker protein were detected by quantitative polymerase chain reaction (qPCR) or Western blot. Dual-luciferase reporter assays were used to verify the targeting relationship between miR-129-5p and PPARγ messenger RNA (mRNA). Human lung epithelial cells BEAS-2B transfected with the miR-129-5p inhibitor and/or the short interfering RNA PPARγ (si-PPARγ) were applied to explore the mechanism.ResultsThe results showed that pioglitazone promoted autophagy and relieved lung injury caused by LPS, while GW9662 exacerbated lung injury. MiR-129-5p directly targeted the PPARγ. Inhibiting the expression of miR-129-5p increased the level of the PPARγ, induced autophagy, and inhibited apoptosis and the inflammatory response. Conversely, silencing the PPARγ had the opposite effects, and blocked the protective effects of the miR-129-5p inhibitor.ConclusionsThe inhibition of miR-129-5p may induce autophagy and inhibit the inflammatory response by promoting the expression of the PPARγ, thereby relieving ARDS.

ADAMTS8 inhibited lung cancer progression through suppressing VEGFA

BackgroundADAMTS8 expression has been identified to be low in many cancers including lung cancer. However, the specific functions and regulatory system of ADAMTS8 remain to be unveiled. PurposeTo study the potential modulatory mechanism of ADAMTS8 in lung cancer in cell and xenograft mice models. MethodsDifferential expression of ADAMTS8 in lung cancer was analyzed on online tools. So was the overall survival curve in association with ADAMTS8/VEGFA expression in lung cancer patients. RT-qPCR was applied to validate the ADAMTS8 expression in lung cancer cell lines H460 and A549, with the normal lung epithelial cell Beas-2b as a control. Thereafter, overexpressed and knockdown plasmids were constructed for transfection. Colony and flow cytometry methods were used for cell proliferation and apoptosis. RT-qPCR and Western blot methods validated the changes in VEGFA after ADAMTS8 regulation in cells. Tube formation and Transwell methods were applied to observe the changes in tube formation and migration in HUVECs induced by tumor conditioned medium (TCM). Stable-transfected cells were injected subcutaneously into nude mice. H&E and Immunohistochemistry were applied to analyze the pathological differences and protein changes of ADAMTS8, VEGFA and CD31. ResultsHigh ADAMTS8 was correlated with high overall survival rate in lung cancer patients. ADAMTS8 was also abnormally downregulated in NSCLC cells. Upregulation of ADAMTS8 suppressed cell proliferation and enhanced apoptosis while downregulation of ADAMTS8 promoted cell proliferation and decreased apoptosis. VEGFA was negatively correlated with ADAMTS8 in lung cancer tissues. Upregulation of ADAMTS8 inhibited VEGFA in mRNA and protein levels. Further, knockdown of ADAMTS8 induced tube formation and migration of HUVECs and upregulation of ADAMTS8 inhibited this. In addition, upregulation of ADAMTS8 in nude mice inhibited tumor growth and also suppressed VEGFA and CD31 in tumors. ConclusionADAMTS8 inhibited lung cancer progression through suppressing VEGFA in lung cancer.

Cerium Oxide Nanoparticles: Synthesis and Characterization for Biosafe Applications

Due to its excellent physicochemical properties, cerium oxide (CeO2) has attracted much attention in recent years. CeO2 nanomaterials (nanoceria) are widely being used, which has resulted in them getting released to the environment, and exposure to humans (mostly via inhalation) is a major concern. In the present study, CeO2 nanoparticles were synthesized by hydroxide-mediated method and were further characterized by Scanning Electron Microscopy (SEM), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDX), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Diffraction Spectroscopy (XRD). Human lung epithelial (Beas-2B) cells were used to assess the cytotoxicity and biocompatibility activity of CeO2 nanoparticles. 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) and Live/Dead assays were performed to determine the cytotoxicity and biocompatibility of CeO2 nanoparticles. Generation of reactive oxygen species (ROS) by cerium oxide nanoparticles was assessed by ROS assay. MTT assay and Live/Dead assays showed no significant induction of cell death even at higher concentrations (100 μg per 100 μL) upon exposure to Beas-2B cells. ROS assay revealed that CeO2 nanoparticles did not induce ROS that contribute to the oxidative stress and inflammation leading to various disease conditions. Thus, CeO2 nanoparticles could be used in various applications including biosensors, cancer therapy, catalytic converters, sunscreen, and drug delivery.

Molecularly Imprinted Hydrogels Selective to Ribavirin as New Drug Delivery Systems to Improve Efficiency of Antiviral Nucleoside Analogue: A Proof-of-Concept Study with Influenza A Virus.

This study describes the synthesis and evaluation of different imprinted hydrogels using ribavirin as template molecule. Ribavirin serves as a model molecule because it possesses a broad-spectrum antiviral effect against RNA viruses, which are expected as emerging viruses. The choice of monomers enables to stabilize the pre-polymerization complex and to synthesize biocompatible polymers. Predictive studies as well as experimental works conclude similar results on best ribavirin:monomers ratios. Thus, materials exhibit high selective cavities toward ribavirin. These affinities allow to show release profiles drastically different from the non-imprinted ones at two temperatures. The imprinted materials show a sustained profile able to release antiviral for more than 24 h. The hydrogels obtained are biocompatible with model cells retained, human lung epithelial BEAS-2B cells. Cell viability is excellent and pro-inflammatory response is insignificant when imprinted polymers are incubated with cells. Finally, viral tests carried out on Influenza A infected lung cells show that imprinted delivery systems delivering 1 to 3µg of antiviral have the same efficiency as a medium containing 30µg mL-1 of active agent. As a very interesting result, the molecularly imprinted polymers as drug delivery systems allow to increase the local concentration of antiviral, to improve their delivery when its bioavailability is low.

Compatibility characteristics of Bufei Yishen formula III in regulating chronic obstructive pulmonary disease mucus hypersecretion

To evaluate the compatibility laws of effective-component compatibility of Bufei Yishen formula III (ECC-BYF III) in regulating mucus hypersecretion of chronic obstructive pulmonary disease (COPD). According to the efficacy of the original Chinese medicine, the components of ECC-BYF III were divided into four categories: Buqi (Ginsenoside Rh1+Astragaloside), Bushen (Icariin), Huatan (Nobiletin), and Huoxue (Paeonol). The four categories were divided into 14 groups based on the method of mathematical permutation. (1) The rats were divided into control group, model group, ECC-BYF III, and different components compatibility groups according to the random number table, totaling 17 groups. COPD rat model in stable phase was established by cigarette smoke exposure combined with repeated bacterial infections. The corresponding drugs were given by gavage at the 9th week of modeling, and the samples were collected at the end of the 16th week. The levels of matrix metalloproteinase-9 (MMP-9) and tissue inhibitors of metalloproteinase 1 (TIMP-1) in serum and bronchoalveolar lavage fluid (BALF), and the levels of mucin (MUC) 5AC in lung tissue and BALF were detected by enzyme linked immunosorbent assay (ELISA). (2) Human lung epithelial cells BEAS-2B were divided into blank group, model group, and different components compatibility groups. Hypoxia-induced mucus hypersecretion model of human lung epithelial cells BEAS-2B was established 4 hours after corresponding drug pretreatment. The mRNA expressions of MUC5AC, MUC5B, and MUC1 were detected by quantitative polymerase chain reaction (PCR). The mucus secretion indexes of rats and BEAS-2B cells were evaluated by Region (R) value comprehensive evaluation method. (1) Compared with the control group, MMP-9 in serum and BALF from the model group were significantly increased, the level of TIMP-1 was significantly decreased, and MUC5AC in lung tissue and BALF were significantly increased. The results of R value comprehensive evaluation showed that except for the Buqi and Bushen groups, ECC-BYF III and other components compatibility groups significantly corrected mucus hypersecretion in COPD rats, ECC-BYF III, Bushen Quxie, Fuzheng Huatan, and Quxie groups were much better (R values were 2.15±0.42, 2.11±0.23, 2.16±0.23 and 2.16±0.55, respectively), compared with the model group (R value: 3.00±0.00), the differences were statistically significant (all P < 0.05). (2) Compared with the blank group, the mRNA expressions of MUC5AC, MUC5B, and MUC1 increased in the model group. But different components compatibility groups had no significant effects on the mucus secretion of BEAS-2B cells. (3) The comprehensive evaluation results of R value about each in vivo and in vitro index showed that ECC-BYF III, Huoxue, Quxie, Bushen Huoxue, Fuzheng Huatan, Buqi Quxie groups significantly corrected the mucus hypersecretion (R values were 2.30±0.43, 2.33±0.44, 2.12±0.68, 2.27±0.64, 2.24±0.27 and 2.29±0.47, respectively), compared with the model group (R value: 3.00±0.00), the difference was statistically significant (all P < 0.01). The order was: Quxie > Fuzheng Huatan > Bushen Huoxue > Buqi Quxie > ECC-BYF III > Huoxue. Different components compatibility of ECC-BYF III had different effects on COPD mucus secretion. The components containing Huatan (Nobiletin) or Huoxue (Paeonol) showed a better inhibitory effect on mucus secretion.

Theaflavin-3,3'-digallate attenuates cigarette smoke extract-induced pulmonary emphysema in mice by suppressing necroptosis.

Pulmonary emphysema is one of the most important pathological manifestations of chronic obstructive pulmonary disease and is commonly associated with cigarette smoking. Previous studies have indicated that necroptosis, a novel non-apoptotic cell death mechanism associated with inflammation and oxidative stress, may contribute to the development of pulmonary emphysema. Theaflavin-3,3'-digallate (TF-3), one of the theaflavins present in black tea, is known to possess several bioactive properties. In the present study, it was demonstrated that TF-3 significantly reduced the generation of reactive oxygen species and the mRNA expression levels of TNF-α, IL-1β and IL-6 in CSE-treated human normal lung epithelial BEAS-2B cells. To further explore the role of TF-3 in necroptosis, the necroptotic rates of BEAS-2B cells were examined via flow cytometry and immunofluorescence assays. The results demonstrated that TF-3 may suppress necroptosis in CSE-treated BEAS-2B cells. Furthermore, it was determined that TF-3 significantly inhibited the CSE-induced phosphorylation of p38 MAPK, receptor-interacting serine/threonine-protein kinase three (RIPK3) and mixed lineage kinase domain-like (MLKL) in BEAS-2B cells. Another experiment demonstrated that a pharmacological inhibitor of the p38 MAPK pathway, SB203580, significantly reduced the protein expression levels of phosphorylated (p)-RIPK3 and phosphorylated (p-)MLKL, which indicated that TF-3 suppressed necroptosis via the p38 MAPK/RIPK3/MLKL signaling pathways. In vivo, it was observed that TF-3 treatment significantly attenuated morphological lung injury in mice with CSE-induced emphysema. Moreover, TF-3 significantly reduced the levels of proinflammatory cytokines, TNF-α and IL-1β and significantly enhanced the antioxidant capacity of the lung tissues in mice with emphysema. TF-3 also significantly inhibited the levels of p-RIPK3 and p-MLKL in the lungs of mice with emphysema. Therefore, the present study indicated that TF-3 may attenuate CSE-induced emphysema in mice by inhibiting necroptosis.

Abstract 2663: Determining the role of altered redox metabolism in lung tumorigenesis

Abstract The purpose of this study is to determine the pathways by which short-term cigarette smoke exposure induces expression of the cystine-glutamate antiporter xCT (SLC7A11) and its downstream implications in carcinogenesis. BEAS-2B lung epithelial cells and their tumorigenic counterpart, B39-TL cells, were exposed to cigarette smoke condensate (CSC) for 3-15 days. Cells were also exposed to a range of inhibitors. Erastin and buthionine sulfoximine (BSO) are inhibitors of various steps in the glutathione synthesis pathway, found to be hyperactive in xCT-overexpressing cells. Cells were also exposed to the drug mito-2-hydroxybenzoic acid (mito-2-HOBA), which scavenges isolevuglandins, reactive γ-ketoaldehydes implicated in oxidative stress and carcinogenesis. Expression of xCT and related proteins was measured using Western blotting. Glutathione levels were detected using the luciferase-based GSH-Glo assay (Promega). Oxidative stress was detected using dihydroethidium (DHE) fluorescence. It was found that CSC exposure significantly increased the expression of xCT and SLC1A5, a transporter that potentially works in synergy with xCT, and that tumorigenic B39-TL cells had significantly increased xCT and SLC1A5 expression compared to BEAS-2B cells. In addition, BEAS-2B cells exposed to CSC and a glutathione synthesis inhibitor such as erastin or BSO showed faster depletion of glutathione than cells treated with only inhibitor. Finally, it was found that BEAS-2B cells treated for 3 days with CSC did not show increased levels of superoxide compared to control cells. However, cells treated with CSC and mito-2-HOBA together showed significantly increased superoxide. These data suggest that CSC induces an antioxidant response which is ablated by mito-2-HOBA. This antioxidant response seems to at least partially rely on glutathione synthesis fueled by xCT, as evidenced by inhibitor studies. The response also seems to be activated by isolevuglandins, because removing these molecules significantly raises oxidative stress. The mechanistic link between CSC exposure, isolevuglandin generation, and xCT/glutathione induction will be clarified in further experiments. Citation Format: Alex Camai. Determining the role of altered redox metabolism in lung tumorigenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2663.

Abstract LB191: Downregulation of Stem-loop binding protein by nicotine and its role in nicotine-induced cell transformation in human lung epithelial cells

Abstract The use of electronic-cigarettes has increased substantially in recent years among the younger population in particular. The liquid nicotine is the main component of the e-cigarette. Mice exposed to e-cigarette smoke (ECS) generated by heating the liquid nicotine developed lung adenocarcinoma and bladder hyperplasia. This implicated a potential role for ECS/nicotine in cancer development, while the underlying mechanisms remain unclear. Here we report that nicotine reduces the protein level of Stem-loop binding protein (SLBP), a critical factor for the stability, processing and translation of canonical histone pre-mRNAs, in human lung epithelial BEAS-2B cells. It has been known that canonical histone mRNAs typically do not end in a poly(A) tail and that depletion of SLBP results in polyadenylation of canonical histone mRNAs that appeared to be carcinogenic. Indeed, nicotine exposure induced polyadenylation of mRNAs for histones H2A, H2B, H3.1, H3.2, and H4. Interestingly, the inhibitor for nAChRs (nicotinic acetylcholine receptors) reversed nicotine-induced SLBP depletion. Moreover, the depletion of SLBP was attenuated not only by both the inhibitors and siRNAs specific for CDK1/2 and CK2, but also by inhibition of AKT signal pathway. Importantly, nicotine-induced anchorage-independent cell growth was rescued by overexpression of SLBP. These results suggest that activation of nAChR and a series of signal transduction pathways are involved in nicotine-mediated SLBP reduction and they may play an important role in nicotine-induced cell transformation and carcinogenesis.Keywords: Nicotine, Stem-loop binding protein, Cell transformation, nAChR Citation Format: Qi Sun, Danqi Chen, Chunyuan Jin. Downregulation of Stem-loop binding protein by nicotine and its role in nicotine-induced cell transformation in human lung epithelial cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB191.

HHLA2 deficiency inhibits non-small cell lung cancer progression and THP-1 macrophage M2 polarization.

BackgroundHuman endogenous retrovirus‐H long terminal repeat‐associating protein 2 (HHLA2) is a member of B7 family, which is upregulated in multiple tumors. However, its exact functions in non‐small cell lung cancer (NSCLC) have not been fully understood. This study aimed to investigate the biological roles of HHLA2 in human NSCLC and the relevant mechanisms. In addition, the effects of tumor cell‐derived HHLA2 on tumor‐associated macrophage (TAM) polarization were explored.MethodsNSCLC cell growth, migration, and invasion were assessed by colony formation and modified Boyden chamber assays. Cell cycle and the CD163+ TAMs were examined by flow cytometry. A co‐culture model of THP‐1 macrophages and NSCLC cells was conducted to investigate the impacts of tumor cell‐derived HHLA2 on THP‐1 macrophage polarization. Moreover, a xenograft nude mouse model was established to explore the effects of HHLA2 on tumorigenesis in vivo.ResultsHHLA2 was upregulated in A549 and H1299 cells compared with the normal lung epithelial BEAS‐2B cells. HHLA2 deficiency inhibited NSCLC cell proliferation, migration, invasion, and induced G0/G1 phase arrest partially via inhibiting EGFR/MAPK/ERK signaling pathway. Furthermore, HHLA2 knockdown inhibited M2 polarization of TAMs via downregulating IL‐10. In addition, knockdown of HHLA2 inhibited tumor growth in vivo.ConclusionHHLA2 downregulation inhibited NSCLC growth and TAM M2 polarization. HHLA2 may serve as a therapeutic target and promising prognostic biomarker in NSCLC.

Ubiquitin-Specific Protease 14 (USP14) Aggravates Inflammatory Response and Apoptosis of Lung Epithelial Cells in Pneumonia by Modulating Poly (ADP-Ribose) Polymerase-1 (PARP-1).

Pneumonia is one of the common respiratory diseases in pediatrics. Ubiquitin-specific protease 14 (USP14) contributes the progress of inflammation-associated diseases. Poly (ADP-ribose) polymerase-1 (PARP-1) involves in the signal transduction of inflammatory pulmonary disease. This study aims to identify the precise function and elaborate the regulatory mechanism of USP14/PARP-1 in the injury of lung epithelial cells. Human lung epithelial BEAS-2B cells received lipopolysaccharide (LPS) (0, 1, 5, and 10 mg/L) treatment for 16 h, establishing in vitro pneumonia model. USP14 protein and mRNA levels in LPS-injured lung epithelial cells were separately assessed using western blot and RT-qPCR analysis. Lung epithelial cells were transfected with siRNA-USP14 or OV-USP14 to perform gain- or loss-of-function experiments. CCK-8 assay was applied to assess cell viability. TUNEL staining and western blot analysis were adopted to determine cell apoptosis. In addition, release of inflammatory cytokines and nitric oxide (NO) was detected using the commercial kits. Meanwhile, PARP-1 protein levels in LPS-injured lung epithelial cells were detected by performing western blot assay. Moreover, Co-IP assay was utilized for detection of the interaction between USP14 and PARP-1. The regulatory effects of PARP-1 on USP14 function in LPS-injured lung epithelial cells were also investigated. LPS dose-dependently reduced viability of lung epithelial cells and elevated USP14 protein. USP14 combined with PARP-1 and increased PARP-1 expression. USP14 elevation exacerbated inflammatory injury and boosted the apoptosis of LPS-injured lung epithelial cells, which was reversed upon downregulation of PARP-1. To sum up, USP14 promotion exacerbated inflammatory injury and boosted the apoptosis of LPS-injured lung epithelial cells by upregulating PARP-1 expression. These findings may represent a therapeutic target for clinical intervention in pneumonia.

Toxicity of Water- and Organic-Soluble Wood Tar Fractions from Biomass Burning in Lung Epithelial Cells.

Widespread smoke from wildfires and biomass burning contributes to air pollution and the deterioration of air quality and human health. A common and major emission of biomass burning, often found in collected smoke particles, is spherical wood tar particles, also known as “tar balls”. However, the toxicity of wood tar particles and the mechanisms that govern their health impacts and the impact of their complicated chemical matrix are not fully elucidated. To address these questions, we generated wood tar material from wood pyrolysis and isolated two main subfractions: water-soluble and organic-soluble fractions. The chemical characteristics as well as the cytotoxicity, oxidative damage, and DNA damage mechanisms were investigated after exposure of A549 and BEAS-2B lung epithelial cells to wood tar. Our results suggest that both wood tar subfractions reduce cell viability in exposed lung cells; however, these fractions have different modes of action that are related to their physicochemical properties. Exposure to the water-soluble wood tar fraction increased total reactive oxygen species production in the cells, decreased mitochondrial membrane potential (MMP), and induced oxidative damage and cell death, probably through apoptosis. Exposure to the organic-soluble fraction increased superoxide anion production, with a sharp decrease in MMP. DNA damage is a significant process that may explain the course of toxicity of the organic-soluble fraction. For both subfractions, exposure caused cell cycle alterations in the G2/M phase that were induced by upregulation of p21 and p16. Collectively, both subfractions of wood tar are toxic. The water-soluble fraction contains chemicals (such as phenolic compounds) that induce a strong oxidative stress response and penetrate living cells more easily. The organic-soluble fraction contained more polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs and induced genotoxic processes, such as DNA damage.

3-Nitrobenzanthrone promotes malignant transformation in human lung epithelial cells through the epiregulin-signaling pathway

Exposure to environmental and occupational contaminants leads to lung cancer. 3-Nitrobenzanthrone (3-nitro-7H-benz[de]anthracen-7-one, 3-NBA) is a potential carcinogen in ambient air or diesel particulate matter. Studies have revealed that short-term exposure to 3-NBA induces cell death, reactive oxygen species activation, and DNA adduct formation and damage. However, details of the mechanism by which chronic exposure to 3-NBA influences lung carcinogenesis remain largely unknown. In this study, human lung epithelial BEAS-2B cells were continuously exposed to 0-10-μM 3-NBA for 6 months. NanoString analysis was conducted to evaluate gene expression in the cells, revealing that 3-NBA-mediated transformation results in a distinct gene expression signature including carbon cancer metabolism, metastasis, and angiogenesis. Alterations in tumor-promoting genes such as EREG (epiregulin), SOX9, E-cadherin, TWIST, and IL-6 were involved in epithelial cell aggressiveness. Kaplan-Meier plotter analyses indicated that increased EREG and IL-6 expressions in early-stage lung cancer cells are correlated with poor survival. In vivo xenografts on 3-NBA-transformed cells exhibited prominent tumor formation and metastasis. EREG knockout cells exposed to 3-NBA for a short period exhibited high apoptosis and low colony formation. By contrast, overexpression of EREG in 3-NBA-transformed cells markedly activated the PI3K/AKT and MEK/ERK signaling pathways, resulting in tumorigenicity. Furthermore, elevated IL-6 and EREG expressions synergistically led to STAT3 signaling activation, resulting in clonogenic cell survival and migration. Taken together, chronic exposure of human lung epithelial cells to 3-NBA leads to malignant transformation, in which the EREG signaling pathway plays a pivotal mediating role. • Short-term exposure of lung epithelial cells to 3-NBA can lead to ROS production and cell apoptosis. • Long-term chronic exposure to 3-NBA upregulates the levels of tumor-promoting genes such as EREG and IL-6. • Increased EREG expression in 3-NBA-transformed cells markedly contributes to tumorigenesis through PI3K/AKT and MEK/ERK activation and synergistically enhances the IL-6/STAT3 signaling pathway, which promotes tumorigenicity.

Luteolin has a significant protective effect against cadmium-induced injury in lung epithelial Beas-2B cells

To investigate the protective effect of luteolin against cadmium (Cd)-induced injury in human lung epithelial Beas-2B cells. Beas-2B cells were treated with different concentrations of luteolin (0-160 μmol/L) or Cd (0-40 μmol/L) for 24 h, and the cell viability was examined using MTT assay. After treatment with luteolin (0.25, 0.5 and 0.75 μmol/L) with or without Cd (5 μmol/L) for 24 h, the cells were examined for viability, lactate dehydrogenase (LDH) activity and morphological changes of the cell nuclei using Hoechst fluorescent staining. The levels of ROS, SOD, GSH and MDA in the treated cells were detected, and the expression levels of Akt, p-Akt and nuclear factor E2-related factor 2 (Nrf2) proteins were determined using Western blotting. Luteolin within the concentration range of 0-80 μmol/L did not significantly affect the survival rate of Beas-2B cells (P>0.05), but Cd at 5 μmol/L significantly decreased the cell viability (P < 0.05) with an IC50 of 24.6 μmol/L. In Cd-treated cells, treatment with luteolin significantly mitigated the decrease of cell viability, reduced LDH release and cell apoptosis, enhanced SOD activity and GSH content, and inhibited the production of MDA and ROS (all P < 0.05). Luteolin also significantly up-regulated the expression levels of p-Akt and Nrf2 protein in Cd-treated Beas-2B cells (P < 0.05). Luteolin has a significant protective effect against Cd-induced injury in Beas-2B cells, and the effects are probably mediated, at least in part, by promoting the activation of Akt and Nrf2.

Depletion of Stem‐loop binding protein and polyadenylation of canonical histone mRNAs by nicotine

The use of electronic-cigarettes has increased substantially in recent years among the younger population in particular. The liquid nicotine is the main component of the e-cigarette. Mice exposed to e-cigarette smoke (ECS) generated by heating the liquid nicotine developed lung adenocarcinoma and bladder hyperplasia. This implicated a potential role for ECS/nicotine in cancer development, while the underlying mechanisms remain unclear. Here we report that nicotine reduces the protein level of Stem-loop binding protein (SLBP), a critical factor for the stability, processing and translation of canonical histone pre-mRNAs, in human lung epithelial BEAS-2B cells. It has been known that canonical histone mRNAs typically do not end in a poly(A) tail and that depletion of SLBP results in polyadenylation of canonical histone mRNAs that appeared to be carcinogenic. Indeed, nicotine exposure induced polyadenylation of mRNAs for histones H2A, H2B, H3.1, H3.2, and H4. Interestingly, the inhibitor for nAChRs (nicotinic acetylcholine receptors) reversed nicotine-induced SLBP depletion. Moreover, the depletion of SLBP was attenuated not only by both the inhibitors and siRNAs specific for CDK1/2 and CK2, but also by inhibition of AKT signal pathway. Importantly, nicotine-induced anchorage-independent cell growth was rescued by overexpression of SLBP. These results suggest that activation of nAChR and a series of signal transduction pathways are involved in nicotine-mediated SLBP reduction and they may play an important role in nicotine-induced cell transformation and carcinogenesis.