Lung Epithelial BEAS-2B Cells Research Articles

The impact of pyrolysis temperature on physicochemical properties and pulmonary toxicity of tobacco stem micro-biochar

Biochars (BCs) are currently widely used, yet their impact on human health is mostly unknown. We generated micro-tobacco stem-pyrolysed BCs (mTBCs) at different pyrolysis temperatures and assessed pulmonary toxicity in normal human lung epithelial BEAS-2B cells. mTBCs generated at 350 °C (mTBC350) and 650 °C (mTBC650) were analysed and compared for physicochemical properties and adverse effects. Pyrolysis temperature had a significant influence on chemical composition, particle size, specific surface area and aromatic carbon structure. mTBC650 displayed a highly ordered aromatic carbon structure with smaller particle size, high surface area (20.09 m2/g) and high polycyclic aromatic hydrocarbon and metal content. This composition could promote reactive oxygen species accumulation accompanied by greater cytotoxicity, genotoxicity and epithelial barrier malfunction in cultured cells. Thus, the risk of pulmonary toxicity owing to micro-BCs (mBCs) is affected by pyrolysis temperature. Long-term exposure to mBCs produced at high temperatures may lead to or exacerbate pulmonary disease.

LncRNA MEG8 promotes tumor progression of non-small cell lung cancer via regulating miR-107/CDK6 axis.

Mounting evidence has implicated the vital role of long noncoding RNAs (lncRNAs) in non-small cell lung cancer (NSCLC). This study aims to investigate the mechanism of lncRNA MEG8 on NSCLC progression. The mRNA expressions of MEG8 and miR-107 were examined in tumor and adjacent normal tissues from patients with NSCLC by qRT-PCR. Lung epithelial BEAS-2B cells were transfected with MEG8 overexpression plasmid, and NSCLC A549 and H1299 cells were transfected with MEG8 or miR-107 overexpression/knockdown plasmid to detect the function of MEG8 or miR-107 on cell activity. The function of MEG8 and miR-107 on cell proliferation, cell cycle changes, invasion and migration was separately determined by Cell counting kit-8 assay and 5-ethynyl-2'-deoxyuridine staining, flow cytometry, transwell and cell scratch test. Target sites for miR-107 and MEG8, miR-107 and CDK6 were determined and verified by a dual luciferase gene reporter assay. The expression levels of the Rb/E2F3 signal pathway related proteins (p21, p27, E2F3 and Rb) were inspected by Western blot. MEG8 was strongly expressed while miR-107 was lowly expressed in tumor tissues and cells. Overexpression of MEG8 potentiated cell proliferation, migration and invasion in BEAS-2B cells. Silencing MEG8 or overexpression of miR-107 clearly hindered cell progression in A549 and H1299 cells. Mechanistically, MEG8 and CDK6 can competitively bind to miR-107 and together regulate the progression of NSCLC. Additionally, silencing MEG8 or overexpression of miR-107 can inhibit the phosphorylation levels of Rb and E2F3. Evidence in this work indicated that MEG8 regulates miR-107/CDK6 axis to promote NSCLC progression by activating the Rb/E2F3 pathway.

High levels of boron promote anchorage-independent growth of nontumorigenic cells

WHO has presented a health-based guideline value for boron in drinking water. That fact indicates that a high level of boron is toxic for humans. However, there is no direct evidence of boron-mediated malignant transformation. In this study, human lung epithelial nontumorigenic BEAS-2B cells and tumorigenic A549 cells were used to investigate the tumorigenic toxicity of boron in vitro. Anchorage-independent growth, a hallmark of malignant transformation, was increased by boron at concentrations of 50, 250 and 500 μM in BEAS-2B cells, though the same concentrations of boron had no influence on anchorage-independent growth of A549 cells. Moreover, boron at concentrations of 250 and 500 μM activated the c-SRC/PI3K/AKT pathway of BEAS-2B cells. The results of our in vitro study suggest that exposure to high levels of boron promotes transforming activity of nontumorigenic cells.

Kinesin superfamily protein 21B acts as an oncogene in non-small cell lung cancer

BackgroundKinesin superfamily proteins (KIFs) serve as microtubule-dependent molecular motors, and are involved in the progression of many malignant tumors. In this study, we aimed to investigate the expression pattern and precise role of kinesin family member 21B (KIF21B) in non-small cell lung cancer (NSCLC).MethodsKIF21B expression in 72 cases of NSCLC tissues was measured by immunohistochemical staining (IHC). We used shRNA-KIF21B interference to silence KIF21B in NSCLC H1299 and A549 cells and normal lung epithelial bronchus BEAS-2B cells. The biological roles of KIF21B in the growth and metastasis abilities of NSCLC cells were measured by Cell Counting Kit-8 (CCK8), colony formation and Hoechst 33342/PI, wound-healing, and Transwell assays, respectively. Expression of apoptosis-related proteins was determined using western blot. The effect of KIF21B on tumor growth in vivo was examined using nude mice model.ResultsKIF21B was up-regulated in NSCLC tissues, and correlated with pathological lymph node and pTNM stage, its high expression was predicted a poor prognosis of patients with NSCLC. Silencing of KIF21B mediated by lentivirus-delivered shRNA significantly inhibited the proliferation ability of H1299 and A549 cells. KIF21B knockdown increased apoptosis in H1299 and A549 cells, down-regulated the expression of Bcl-2 and up-regulated the expression of Bax and active Caspase 3. Moreover, KIF21B knockdown decreased the level of phosphorylated form of Akt (p-Akt) and Cyclin D1 expression in H1299 and A549 cells. In addition, silencing of KIF21B impeded the migration and invasion of H1299 and A549 cells. Further, silencing of KIF 21B dramatically inhibited xenograft growth in BALB/c nude mice. However, silencing of KIF21B did not affect the proliferation, migration and invasion of BEAS-2B cells.ConclusionsThese results reveal that KIF21B is up-regulated in NSCLC and acts as an oncogene in the growth and metastasis of NSCLC, which may function as a potential therapeutic target and a prognostic biomarker for NSCLC.

Anthocyanin-rich haskap (Lonicera caerulea L.) berry extracts reduce nitrosamine-induced DNA damage in human normal lung epithelial cells in vitro

Diets rich in polyphenols are known to reduce cancer among high-risk populations. Haskap (Lonicera caerulea L.) berry has abundant phenolic acids and flavonoids, especially anthocyanins. Tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) present in cigarette smoke, is a major lung carcinogenic factor. We analyzed the efficacy of anthocyanin-rich haskap berry extracts in preventing DNA damage induced by 4-[(acetoxymethyl) nitrosamino]-1-(3-pyridyl)-1-butanone (NNKOAc), a precursor of NKK, in human lung epithelial BEAS-2B cells in vitro. A cocktail of monomeric polyphenols from haskap berries was extracted separately in ethanol and water and profiled. Sub-lethal concentrations of NNKOAc were used to induce DNA damage in BEAS-2B cells, and a cell viability assay was performed to confirm that the tested concentrations of haskap extracts were not cytotoxic to BEAS-2B cells. Cells were pre-treated with the haskap extracts prior to NNKOAc exposure. Dose-dependent DNA damage was observed with carcinogenic NNKOAc, but did not occur in the presence of the haskap extracts. Pre-treatment of the cells with the haskap extracts significantly reduced NNKOAc-induced DNA damage, DNA fragmentation, and intracellular reactive oxygen species and upregulated the ATM-dependent DNA damage repair cascade compared to non-treated BEAS-2B cells. The protective effect of haskap extracts could be related to their polyphenol content and high antioxidant capacity.

Silencing of PRDX2 Inhibits the Proliferation and Invasion of Non-Small Cell Lung Cancer Cells.

Peroxiredoxin 2 (PRDX2), a member of the peroxiredoxin family of antioxidant enzymes, has been revealed to be an important player in cancer progression. However, the biological role of PRDX2 in the progression of non-small cell lung cancer (NSCLC) is poor reported. In the present study, the loss-of-function experiments were performed to investigate the specific role of PRDX2 in the growth and invasion of NSCLC. The results revealed that knockdown of PRDX2 by siRNA interference significantly suppressed the proliferation, migration, and invasion of A549 and H1299 cells, as well as diminished the activity of MMP9. Additionally, the decrease in PRDX2 expression significantly promoted apoptosis in NSCLC cells by downregulating expression of Bcl-2 and upregulating the expression of Bax, cleaved caspase 3 and cleaved caspase 9, but had no significant effect on the apoptosis of normal lung epithelial cells BEAS-2B. Moreover, PRDX2 inhibitor also inhibited the proliferation, migration, and invasion of A549 cells and promoted apoptosis. Further, our data demonstrated that silencing of PRDX2 markedly reduced the phosphorylation of Akt and mTOR and expression of downstream proteins Cyclin D1 and p70S6k. In conclusion, our findings indicate that PRDX2 exerts a prooncogenic role in the progression of NSCLC and might be a potential therapeutic target for NSCLC treatment.

Toxicity mechanism of tetrabromobisphenol A to human respiratory system cells 16HBE and Beas2B

Tetrabromobisphenol A (TBBPA) is a high-production chemical widely used in printed circuit boards and other polymeric materials for inflaming. As an environmental pollutant, it is widely found in various abiotic and biological media. Usually, the TBBPA could enter the body through skin contact, respiratory exposure and the dietary intake, among which respiratory exposure may be a most important exposure route. Previous studies reported that TBBPA possesses the endocrine, liver and kidney toxicity. However, few studies focused on the effects of TBBPA on respiratory toxicity. Therefore, it is urgent to study the toxic effects of TBBPA on respiratory system. In this study, human bronchial cells Beas2B and pulmonary epithelial cells 16HBE were used as subjects to study the exposure toxicity of TBBPA. Firstly, the viability and permeability of cells were assayed during the TBBPA exposure process. When TBBPA was in low concentration range (0−0.4 μmol/L), 24 h of exposure cannot significantly affect cell viability. When concentration of TBBPA was greater than 10 μmol/L, the inhibitory effect on cell activity was obviously observed. When concentration of TBBPA was up to 50 μmol/L, the cell viabilities of 16HBE and Beas2B cells decreased to 80.9% and 86.2%. It is worth noting that, as compared with bronchial epithelial cell 16HBE, lung epithelial cell Beas2B has a higher tolerance to TBBPA, which may be due to the different cell structures. In addition, the oxidation stress of cells was also determined by assaying the cell intracellular reactive oxygen species (ROSs), antioxidant enzymatic activity of superoxide dismutase (SOD) and catalase (CAT) during the whole expose duration. The results showed that the levels of intracellular ROSs obviously increased in both cells, indicating that peroxidation occurred in the cells during TBBPA exposure. Correspondingly, the enzymatic activities of SOD and CAT also increased, indicating that oxidative stress happened in cells. After that, flow cytometry was applied to analyze cell apoptosis. The results showed that partial apoptosis occurred after 24 h of TBBPA exposure, indicating that TBBPA could induce cell apoptosis. Besides, with the increase of exposure concentration, the apoptosis rate of the two kinds of cells also increased. Furthermore, the q-PCR was used to determine the apoptosis-related gene expression. The results revealed that the expression levels of apoptosis-related genes p53, Survivin , bax , bcl-2 , caspase-3 , caspase-9 were all up-regulated to different degrees, further confirming that cells were apoptotic caused by TBBPA. Further, compared with the 12-h exposure data, 24-h exposure would stimulate more intense expression up-regulation. In all, this research mainly investigated the toxicity of typical generation bromide flame retardants TBBPA on human bronchial epithelial cells 16 HBE and lung epithelial cells Beas2B. Results showed that the exposure of TBBPA could cause damage to cell viability and elicit oxidative stress in cells, which could further induce cell apoptosis. The results of cytotoxicity related to human respiratory system in this work can provide a scientific basis for revealing the health risk of toxic organic pollutants to human respiratory system.

Study on the mechanism of long non-coding RNA migration inhibitory factor antisense RNA1 in regulating proliferation, invasion and metastasis of non-small cell lung cancer

Objective To explore the molecular mechanism by which long non-coding RNA (lncRNA) migration inhibitory factor antisense RNA1 (MIF-AS1)/microRNA (miRNAM miR)-370-3p/mitogen activated protein kinase 9 (MAP3K9) molecular axis regulates proliferation, invasion and migration of non-small cell lung cancer (NSCLC). Methods Twenty cancer samples of NSCLC patients were collected from Henan Provincial People’s Hospital from May 2017 to January 2019. There were 12 males and 8 females, aged (52.37±10.34) years. Real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) and Western blotting were used to detect the expression levels of MIF-AS1, miR-370-3p and MAP3K9 in cancer tissues and 9 cell lines. NSCLC A549 cells were transfected with si-MIF-AS1, si-NC, si-MIF-AS1+ anti-miR-370-3p or si-MIF-AS1+ pcDNA-MAP3K9, respectively. Methyl thiazol tetrazolium (MTT) assay and Transwell assay were used to detect the proliferation, migration and invasion of transfected cells. Western blotting was used to detect the expression of Cyclin D1, p21, p27, matrix metalloproteinase (MMP)-2, MMP-9 and MMP-14 proteins. The dual luciferase reporter gene verified the targeting regulation of MIF-AS1 on miR-370-3p and miR-370-3p on MAP3K9. Results The expression of MIF-AS1 and MAP3K9 in NSCLC tissues (2.49±0.25 and 2.24±0.22) and A549 cells (2.54±0.24 and 2.31±0.23), H1299 cells (2.11±0.21 and 2.44±0.24) and PC-9 cells (2.26±0.23 and 2.16±0.22) was significantly higher than that in adjacent tissues (1.00±0.09 and 1.02±0.09) and normal lung epithelial cells BEAS-2B (1.01±0.09 and 1.00±0.09) (t=25.078, P<0.05; F=94.367, P<0.05). The expression of miR-370-3p in NSCLC tissues (0.42±0.04), A549 cells (0.34±0.03), H1299 cells (0.53±0.05), and PC-9 cells (0.44±0.04) was significantly lower than that in adjacent tissues (1.01±0.08) and BEAS-2B cells (1.00±0.08) (t=29.500, P<0.05; F=269.552, P<0.05). Transfection with si-MIF-AS1 significantly inhibited NSCLC cell proliferation (24 h: 0.27±0.03, 48 h: 0.36±0.03, 72 h: 0.48±0.04), invasion (24.33±3.14), migration (32.46±3.34) ability (P<0.01), up-regulated p21 (0.64±0.06), p27 (0.77±0.07) protein expression (t=17.441, P<0.05; t=17.726, P<0.05) and down-regulated Cyclin D1 (0.29±0.03), MMP-2 (0.25±0.03), MMP-9 (0.34±0.03) and MMP-14 (0.29±0.03) protein expression (t=17.732, P<0.05). The dual luciferase reporter gene confirmed that MIF-AS1 was bond to miR-370-3p and miR-370-3p was bond to MAP3K9. Transfection with si-MIF-AS1+ anti-miR-370-3p or si-MIF-AS1+ pcDNA-MAP3K9 inhibited the effects of si-MIF-AS1 on proliferation, invasion and migration of NSCLC cells. Conclusion LncRNA MIF-AS1 promotes proliferation, migration and invasion of NSCLCs by regulating miR-370-3p/MAP3K9 molecular axis. Key words: Non-small cell lung cancer; Long non-coding RNA migration inhibitory factor antisense RNA1; MicroRNA-370-3p; Mitogen activated protein kinase 9; Proliferation; Migration; Invasion

Astragaloside IV ameliorates intermittent hypoxia-induced inflammatory dysfunction by suppressing MAPK/NF-κB signalling pathways in Beas-2B cells.

Intermittent hypoxia is a characteristic pathological change in obstructive sleep apnoea (OSA) that can initiate oxidative stress reaction and pro-inflammatory cytokine release. The purpose of this study was to assess the effect and protective mechanism of Astragaloside IV (AS-IV) in intermittent hypoxia-induced human lung epithelial Beas-2B cells. Human lung epithelial Beas-2B cells were exposed to intermittent hypoxia or normoxia in the absence or presence of AS-IV. MTT assay was performed to determine the cell viability. The levels of reactive oxygen species (ROS), lactate dehydrogenase (LDH), malonaldehyde (MDA), and superoxide dismutase (SOD) were measured to evaluate oxidative stress. The levels of cytokines interleukin (IL)-8, IL-1β, and IL-6 were evaluated by enzyme-linked immunosorbent assay and real-time PCR. The expression of Toll-like receptor 4 (TLR4), mitogen-activated protein kinase (MAPK), and nuclear transcription factor-kappa B (NF-κB) signalling pathways was analysed by western blot. The results showed that AS-IV significantly reduced the levels of ROS, LDH, MDA, IL-8, IL-1β, and IL-6, and increased the level of SOD in intermittent hypoxia-induced Beas-2B cells. It also suppressed the phosphorylation of MAPKs, including P38, c-Jun N-terminal kinase and extracellular signal-regulated kinase, and inhibited the activation of the NF-κB signalling pathway by reducing the phosphorylation of IκBα and p65. AS-IV attenuates inflammation and oxidative stress by inhibiting TLR4-mediated MAPK/NF-κB signalling pathways in intermittent hypoxia-induced Beas-2B cells.

Human lung epithelial BEAS-2B cells exhibit characteristics of mesenchymal stem cells

BEAS-2B was originally established as an immortalized but non-tumorigenic epithelial cell line from human bronchial epithelium. Because of general recognition for its bronchial epithelial origin, the BEAS-2B cell line has been widely used as an in vitro cell model in a large variety of studies associated with respiratory diseases including lung carcinogenesis. However, very few studies have discussed non-epithelial features of BEAS-2B cells, especially the features associated with mesenchymal stem cells (MSCs), which represent a group of fibroblast-like cells with limited self-renewal and differentiation potential to various cell lineages. In this study, we compared BEAS-2B with a human umbilical cord-derived MSCs (hMSCs) cell line, hMSC1, which served as a representative of hMSCs in terms of expressing common features of hMSCs. It was observed that both BEAS-2B and hMSC1 shared the same expression profile of surface markers of hMSCs and exhibited similar osteogenic and adipogenic differentiation potential. In addition, like hMSC1, the BEAS-2B cell line exhibited suppressive activities on proliferation of mitogen-activated total T lymphocytes as well as Th1 lymphocytes, and IFNγ-induced expression of IDO1, all thus demonstrating that BEAS-2B cells exhibited an almost identical characteristic profile with hMSCs, even though, there was a clear difference between BEAS-2B and hMSCs in the effects on type 2 macrophage polarization. Most importantly, the hMSCs features of BEAS-2B were unlikely a consequence of epithelial-mesenchymal transition. Therefore, this study provided a set of evidence to provoke reconsideration of epithelial origin of BEAS-2B.

Highly selective detection of Pd2+ ion in aqueous solutions with rhodamine-based colorimetric and fluorescent chemosensors

In this study, we report a new class of rhodamine-based fluorescent sensors for highly selective and sensitive detection of Pd2+ ions in aqueous medium. A rhodamine-based palladium sensor RPS and a coumarin-rhodamine Förster resonance energy transfer (FRET)-pair based palladium sensor FPS were synthesized with the designed podand ligand for Pd2+ ion recognition. They showed both colorimetric change and fluorometric change in the presence of Pd2+ ion due to the opening of their spirolactam rings. Both chemosensors are highly selective to Pd2+ over the other 24 different metal ions and they are selective to palladium species in +2 oxidation state, RPS showed a 70-fold fluorescent turn-on while FPS showed a 1.75-fold ratiometric change at I599/I470. Furthermore, RPS showed low cell cytotoxicity and it was successfully used to image Pd2+ in BEAS-2B lung epithelial cells. © 2019 Elsevier Science. All rights reserved.

Naturally-derived diterpenoid sphaeropsidin C as an activator of Nrf2/ARE pathway and its potential capability of relieving intracellular oxidative stress in human lung epithelial cells

Oxidative stress is closely associated to the onset and progression of many human diseases. Activation of the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway using naturally-derived molecules is an efficient strategy for alleviating the intracellular oxidative insults, and thus blocking the pathogenesis of oxidative stress-induced diseases. In the present study, a naturally-derived isopimarane-type diterpenoid sphaeropsidin C (SC) was identified to be an activator of Nrf2/ARE signaling pathway. Our data indicated that SC was able to stimulate Nrf2-mediated defensive system through promoting Nrf2 translocation, inhibiting Nrf2 ubiquitination, and enhancing Nrf2 stability in normal human lung epithelial Beas-2B cells. Furthermore, SC-induced Nrf2 activation required the involvement of protein kinases, exemplified by protein kinase C (PKC), protein kinase R-like endoplasmic reticulum kinase (PERK), and phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K). It alleviated sodium arsenite [As(III)]-induced intracellular oxidative stress in an Nrf2-dependent manner. These results suggested that SC displayed potential application for the prevention and therapy against oxidative stress-induced diseases. Moreover, isopimarane-type diterpenoid represents a promising skeleton for developing Nrf2 activators.

Polystyrene microplastic particles: In vitro pulmonary toxicity assessment

Microplastics (MPs) have become a global environmental concern. Recent studies have shown that MPs, of which the predominant type is often polystyrene (PS; known as PS-MPs), can extend to and affect remote, sparsely inhabited areas via atmospheric transport. Although exposure to inhaled MPs may induce lung dysfunction, further experimental verification of the pulmonary toxic potential of MPs and the mechanism underlying the toxicity is needed. Here we used normal human lung epithelial BEAS-2B cells to clarify the association between pulmonary toxicity and PS-MPs. Results revealed that PS-MPs can cause cytotoxic and inflammatory effects in BEAS-2B cells by inducing reactive oxygen species formation. PS-MPs can decrease transepithelial electrical resistance by depleting zonula occludens proteins. Indeed, decreased α1-antitrypsin levels in BEAS-2B cells suggest that exposure to PS-MPs increases the risk for chronic obstructive pulmonary disease, and high concentrations of PS-MPs can induce these adverse responses. While low PS-MP levels can only disrupt the protective pulmonary barrier, they may also increase the risk for lung disease. Collectively, our findings indicate that PS-MP inhalation may influence human respiratory health.

MicroRNA-140's inhibition on the cell migration and invasion of non-small cell lung cancer by down-regulating Smad3 expression.

To investigate the effect of miR-140 on migration and invasion of non-small cell lung cancer (NSCLC) A549 cell and its regulatory mechanism. The NSCLC cell lines A549, H1650, NCI-H838, and normal lung epithelial cells BEAS-2B were purchased, and the expression of miR-140 and Smad3 in cells was detected by RT-PCR. MiR-140-inhibitor, miR-140-mimincs, miR-NC, sh-Smad3, Si-Smad3, and NC were transfected into A549 cells. Quantitative Real Time-Polymerase Chain Reaction (QRT-PCR) was used to detect the expression of miR-140 and Smad3. Transwell and cell scratch assay were used to detect cell invasion and migration. Dual-Luciferase report assay was used to study the relationship between mir-140 and Smad3. MiR-140 was lowly expressed and Smad3 was highly expressed in NSCLC cells. Cell researches showed that the overexpression of miR-140 can inhibit cell invasion and migration. The downregulation of Smad3 expression inhibits cell invasion and migration. Dual-Luciferase reporter assay showed that miR-140 is a Smad3 targeting site. MiR-140 can inhibit the invasion and migration of NSCLC cells by regulating Smad3, and it is expected to become a potential clinical target.

Nickel-refining fumes induce NLRP3 activation dependent on mitochondrial damage and ROS production in Beas-2B cells

Nickel (Ni) is a silver-white transition metal that is widely used in the production field due to its unique physical and chemical properties. As a toxicant, long-term exposure to Ni can cause rhinitis, pneumonia and other respiratory inflammation. In the present study, we investigated the effect of particles extracted from Ni-refining fumes on cell viability, inflammation-related proteins and mitochondrial damage in human lung epithelial Beas-2B cells. The cells were exposed to Ni-refining fume particles for 24 h at concentrations of 0, 6.25, 12.50 and 25.00 μg/mL. The expression levels of the NACHT-LRR-PYD domains-containing protein 3 (NLRP3), caspase-1, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), interleukin (IL)-1β and tumor necrosis factor (TNF)-α protein in Beas-2B cells exposed to Ni-refining fume particles increased significantly. Downregulation of NLRP3 expression by siRNA decreased the content of IL-1β. During activation of NLRP3, the mitochondrial membrane potential (MMP) decreased, the opening rate of mitochondrial permeability transition pore (MPTP) increased, and the content of reactive oxygen species (ROS) increased. Using lipopolysaccharide (LPS) intervention as the positive control group, N-acetylcysteine (NAC, an effective ROS remover) acted as an inhibitor. After NAC reduced the level of ROS, activation of the NLRP3 inflammasome was significantly inhibited. Ni-refining fumes caused significant cytotoxicity, inflammation and mitochondrial damage in Beas-2B cells. The present study thus provides experimental support for the hypothesis that Ni-refining fumes cause inflammation by inducing ROS production in Beas-2B cells.

Mechanism of VIPR1 gene regulating human lung adenocarcinoma H1299 cells.

The vasoactive intestinal peptide receptor-1(VIPR1) has prominent growth effects on a number of common neoplasms. However, there were contradictions in the effect cross different cancers. We aimed to explore the effect of VIPR1 overexpression on a human lung adenocarcinoma cell line H1299. GEO dataset was used to screen differentially expressed genes in lung adenocarcinoma tissues. The expression of VIPR1 mRNA was determined in the cancer Genome Atlas (TCGA). Immunohistochemical analysis was performed to determine VIPR1 protein expression in lung adenocarcinoma and corresponding adjacent tissues (n = 22). Fluorescence real-time quantitative PCR detected the expression of VIPR1 in human normal lung epithelial cell line BEAS-2B and lung adenocarcinoma cell line H1299. Overexpression strategies were employed to assess functions of VIPR1 expression on several malignant phenotypes in H1299. The expression of VIPR1 was lower in lung adenocarcinoma tissues than that in adjacent tissues. Compared with the normal lung epithelial cells BEAS-2B, VIPR1 was down-regulated in lung cancer cells H1299 (P < 0.05). After the overexpression of VIPR1, we found that VIPR1 significantly inhibited growth, migration, and invasion of H1299 cells (P < 0.05). Our findings point out the tumor suppressor roles of VIPR1 in human LUAD pathogenesis.

Correlation of integrin alpha 7 with clinicopathological characteristics and survival profiles, as well as its regulatory role in cell proliferation, apoptosis, and stemness in non-small-cell lung cancer.

BackgroundThe present study aimed to evaluate the correlation of integrin alpha 7 (ITGA7) with patients' clinicopathological characteristics and survival profiles, as well as its influence on cell proliferation, apoptosis, and stemness in non–small‐cell lung cancer (NSCLC).MethodsA total of 397 NSCLC patients underwent surgical resection were included, and ITGA7 was measured in tumor tissues and adjacent tissues by immunohistochemistry. patients' clinical data were extracted from database, and follow‐up records were reviewed. In cellular experiments, expression of ITGA7 was measured in NSCLC cell lines and normal human lung epithelial cell line by RT‐qPCR. The influence of ITGA7 on cell activity was assessed by transfecting overexpression plasmids and knockdown plasmids of ITGA7 into A549 cells.ResultsIntegrin alpha 7 was upregulated in tumor tissues compared with the adjacent tissues of NSCLC patients. Patients with ITGA7 high expression presented poorer pathological differentiation, larger tumor size, and more advanced TNM stage compared with patients with ITGA7 low expression. For survival profiles, both disease‐free survival and overall survival were shorter in ITGA7 high expression patients compared with ITGA7 low expression patients. In cellular experiments, ITGA7 was upregulated in NCI‐H1650, A549, HCC‐827, and NCI‐H1299 cells compared with normal human lung epithelial cells BEAS‐2B. In addition, ITGA7 promoted cell proliferation, inhibited cell apoptosis, and facilitated cell stemness in A549 cells.ConclusionIntegrin alpha 7 correlates with poor clinicopathological characteristics and survival profiles, and it promotes cell proliferation, stemness but suppresses cell apoptosis in NSCLC.

Pseudomonas aeruginosa Induced Host Epithelial Cell Mitochondrial Dysfunction

The pathogenicity of P. aeruginosa is dependent on quorum sensing (QS), an inter-bacterial communication system that can also modulate host biology. The innate immune function of the lung mucosal barrier is dependent on proper mitochondrial function. The purpose of this study was to define the mechanism by which bacterial factors modulate host lung epithelial cell mitochondrial function and to investigate novel therapies that ameliorate this effect. 3-oxo-C12-HSL disrupts mitochondrial morphology, attenuates mitochondrial bioenergetics, and induces mitochondrial DNA oxidative injury. Mechanistically, we show that 3-oxo-C12-HSL attenuates expression of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), a master regulator of mitochondrial biogenesis, antioxidant defense, and cellular respiration, and its downstream effectors in both BEAS-2B and primary lung epithelial cells. Overexpression of PGC-1α attenuates the inhibition in cellular respiration caused by 3-oxo-C12-HSL. Pharmacologic activation of PGC-1α restores barrier integrity in cells treated with 3-oxo-C12-HSL. These data demonstrate that the P. aeruginosa QS molecule, 3-oxo-C12-HSL, alters mitochondrial pathways critical for lung mucosal immunity. Genetic and pharmacologic strategies that activate the PGC-1α pathway enhance host epithelial cell mitochondrial function and improve the epithelial innate response to P. aeruginosa. Therapies that rescue PGC-1α function may provide a complementary approach in the treatment of P. aeruginosa infection.

The effects of Sestrin2 on apoptosis of heat-exposed lung epithelial cells and its mechanism

To investigate the protective effects of Sestrin2 protein on lung epithelial Beas-2B cells in the heat-exposure environment and its mechanism. Lung epithelial Beas-2B cells were cultured at 37℃, 39℃, 40℃ and 41℃ respectively. Cells were harvested at different times (0, 3, 6 and 12 h) after pancreatin digestion. The expressions of Sestrin2, superoxide dismutase(SOD), reactive oxygen species(ROS), cell mitochondrial membrane potential and apoptosis rate of cells were detected by Western blot, fluorescence spectrophotometer and flow cytometry, respectively. Gene expression sequence was cloned into high expression plasmid pcDNA3.1+. Beas-2B cells were transfected by Lipfectamine 2000 to construct Sestrin2 and SOD high expression cells. The changes of mitochondrial membrane potential and cell apoptosis were observed in the Sestrin2 and SOD high expression cells. With the increase of temperature, the expression level of Sestrin2 protein in heat treatment group was decreased compared with the control group. When Beas-2B cells were exposed to 41℃, the ROS level was increased, mitochondrial membrane potential was decreased significantly and apoptosis rate was increased at different time points. After high expression of Sestrin2 and SOD in the Beas-2B cells, the expression level of ROS was decreased and the change tendency of mitochondrial membrane potential was decreased, and the apoptosis rate was reduced at 41℃ exposure. Sestrin2 can alleviate the apoptosis of lung epithelial cells induced by heat exposure through mitochondrial membrane potential and SOD, which has protective effect on lung epithelial Beas-2B cells.

CRAF mutations in lung cancer can be oncogenic and predict sensitivity to combined type II RAF and MEK inhibition

Two out of 41 non-small cell lung cancer patients enrolled in a clinical study were found with a somatic CRAF mutation in their tumor, namely CRAFP261A and CRAFP207S. To our knowledge, both mutations are novel in lung cancer and CRAFP261A has not been previously reported in cancer. Expression of CRAFP261A in HEK293T cells and BEAS-2B lung epithelial cells led to increased ERK pathway activation in a dimer-dependent manner, accompanied with loss of CRAF phosphorylation at the negative regulatory S259 residue. Moreover, stable expression of CRAFP261A in mouse embryonic fibroblasts and BEAS-2B cells led to anchorage-independent growth. Consistent with a previous report, we could not observe a gain-of-function with CRAFP207S. Type II but not type I RAF inhibitors suppressed the CRAFP261A-induced ERK pathway activity in BEAS-2B cells, and combinatorial treatment with type II RAF inhibitors and a MEK inhibitor led to a stronger ERK pathway inhibition and growth arrest. Our findings suggest that the acquisition of a CRAFP261A mutation can provide oncogenic properties to cells, and that such cells are sensitive to combined MEK and type II RAF inhibitors. CRAF mutations should be diagnostically and therapeutically explored in lung and perhaps other cancers.