Antineoplastic effects of deoxyelephantopin,a sesquiterpene lactone from Elephantopusscaber, on lung adenocarcinoma (A549) cells

OBJECTIVE： Deoxyelephantopin, a sesquiterpene lactone from Elephantopus scaber, showed inhibition of the growth of various tumor cells in vitro. In the present study, we investigated the cytotoxicity and apoptosis-inducing capacity of deoxyelephantopin on lung adenocarcinoma （A549） cells. METHODS： The cytotoxic effect of deoxyelephantopin on A549 cells and normal lymphocytes was evaluated using 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay and 50% inhibitory concentration （IC50） value was determined. The self-renewal and proliferating potential of A549 cells after treatment with deoxyelephantopin were examined by colony formation assay. Cellular morphology of deoxyelephantopin-treated cells was observed using phase- contrast microscopy. The induction of apoptosis was evaluated using acddine orange and ethidium bromide staining, Hoechst 33342 staining, terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end-labeling （TUNEL） assay, DNA fragmentation analysis and Annexin V-fluorescein isothiocyanate staining by flow cytometry. Activation of caspases was detected using fluorogenic substrate specific to caspases 2, 3, 8 and 9 and flow cytometric analysis. The total cellular DNA content and expression of cleaved poly （ADP-ribose） polymerase was also analyzed. RESULTS： Deoxyelephantopin exhibited cytotoxicity to A549 cells （IC50 = 12.287 μg/mL）, however, there was no toxicity towards normal human lymphocytes. Deoxyelephantopin suppressed the colony-forming ability of A549 cells in a dose-dependent manner. Acridine orange, ethidium bromide and Hoechst 33342 staining showed cell shrinkage, chromosomal condensation and nuclear fragmentation, indicating induction of apoptosis. Deoxyelephantopin increased apoptosis of A549 cells, as evidenced by more TUNEL-positive cells. DNA fragmentation and Annexin V staining revealed late-stage apoptotic cell population. Deoxyelephantopin inhibited A549 cell growth by cell cycle arrest at G2/M phase and induced apoptosis through both extrinsic and intrinsic pathways. CONCLUSION： These results suggest that deoxyelephantopin has great potential as a new chemotherapeutic agent to be developed further for the treatment of lung cancer.

In Vitro Evaluation of Cytotoxicity and Oxidative Stress Induced by Multiwalled Carbon Nanotubes in Murine RAW 264.7 Macrophages and Human A549 Lung Cells

Objective To investigate in vitro cytotoxicity and oxidative stress response induced by multiwalled carbon nanotubes （MWCNTs）. Methods Cultured macrophages （murine RAW264.7 cells） and alveolar epithelium cells type II （human A549 lung cells） were exposed to the blank control, DNA salt control, and the MWCNTs suspensions at 2.5, 10, 25, and 100 ug/mL for 24 h. Each treatment was evaluated by cell viability, cytotoxicity and oxidative stress. Results Overall, both cell lines had similar patterns in response to the cytotoxicity and oxidative stress of MWCNTs. DNA salt treatment showed no change compared to the blank control. In both cell lines, significant changes at the doses of 25 and 100 ug/mL treatments were found in cell viabilities, cytotoxicity, and oxidative stress indexes. The reactive oxygen species （ROS） generation was also found to be significantly higher at the dose of 10 ug/mL treatment, whereas no change was seen in most of the indexes. The ROS generation in both cell lines went up in minutes, reached the climax within an hour and faded down after several hours. Conclusion Exposure to MWCNTs resulted in a dose-dependent cytotoxicity in cultured RAW264.7 cells and A549 cells, that was closely correlated to the increased oxidative stress.

Efficiency of combining pomegranate juice with low-doses of cisplatin and taxotere on A549 human lung adenocarcinoma cells

Objective: To test the coalescence effect of two chemotherapy drugs at low effective dose(cisplatin and taxotere) combined with pomegranate juice on A549 cancer cells. Methods: Infrared spectroscopy method is a qualitative test that was performed to ensure the existence of the phytochemicals providing the antioxidant activity through the presence of the hydroxyl group(-OH). The viability of A549 cell line and normal MCs was tested using the neutral red uptake, Clonogenic survival, XTT and Cell migration assays. Results: Our results showed that this combination firstly led to a greater decrease in the viability of cells comparing to those treated with chemotherapy drugs alone, and secondly led to a significant reduction in cell migration. Conclusions: These data suggest a synergistic effect between the pomegranate and cisplatin which makes probably this combination a powerful option for treating lung adenocarcinoma and in parallel minimizing the systemic side effects.

Inhibitory Effect of Cantharidin on Proliferation of A549 Cells

Objective： To study the inhibition of Cantharidin against the proliferation of human lung cancer A549 cells and its mechanism. Methods： MTT assay was employed to determine the inhibition of Cantharidin against proliferation of A549 cells and flow Cytometry was applied to analyze A549 cell cycle and the effect of Cantharidin on cell cycle. Results： Cantharidin showed inhibition against the proliferation of A549 cells, and the inhibition was mediated by blocking A549 cell cycle at G2/M phase significantly. Conclusion： Cantharidin exhibits inhibition against the proliferation of human lung cancer A549 cells.

Influence of Tamoxifen or the combination of Tamoxifen and Cisplatin on the growth of human lung adenocarcinoma A549 cells

The experiment aims to investigate the influence of Tamoxifen and the combination of Tamoxifen and Cisplatin （DDP） on the growth of human lung adenocarcinoma A549 cells. Methods： We treated human lung adenocarcinoma A549 cells with different concentrations of Tamoxifen, DDP and combination of DDP and Tamoxifen with non-toxicity for 72 h. Then we calculated the inhibition rate through MTT approach and detected the apoptosis rate by flow cytometry. The statistical analysis was performed with SPSS 13.0 software and statistical differences were determined by one-way ANOVA. The data were expressed as the mean ＋ standard deviation and all experiments were performed in three times. The value of P 〈 0.05 was considered to indicate a statistically significant difference. Results： 1. The inhibition rates of Tamoxifen with 2.5 pmol/L, 5 tJmol/L, 10 μmol/L, and 20 μmol/L on the growth of the A549 cells were 18.7%, 25.8%, 54% and 98.8%, respectively （P = 0.000）. Tamoxifen with concentration of 1 μmol/L has no obvious cytoxicity on the A549 cells （P 〉 0.05）. 2. As the increase concentration of Tarnoxifen, the S stage and G2/M of the A549 cells decreased while the G0/G1 increased. The apoptosis rate of Tamoxifen with 0 μmol/L, 0.1 μmol/L, 1 μmol/L and 10 μmol/L on the A549 cells were 6.51%, 8.91%, 17.97% and 42.7%, respectively. 3. The inhibition rates of combination of Tamoxifen with 1 μmol/L and DDP with 1.25 μg/mL, 2.5 μg/mL, 5 μg/mL, 10 μg/mL and 20 μg/mL on the A549 cells were 40.4%, 54.4%, 72.9%, 86.1% and 92.4%, respectively （P 〈 0.05）. Conclusion： Tamoxifen can inhibit the proliferation of human lung adenocarcinoma A549 cells and induce the apoptosis of the A549 cells. The combination of Tamoxifen with non-toxicity and DDP can improve the sensitivity of chemotherapy on the A549 cells.

Digital gene expression profiling analysis of A549 cells cultured with PM10 in moxa smoke

Background:Moxibustion is a traditional Chinese medicine therapy to cure diseases by fumigating meridians or affected parts via burning of moxa floss.Moxa smoke(MS)is one of the key factors in moxibustion.In this study,we adopted digital gene expression profiling,a next-generation gene sequencing technology,to investigate the effect of MS,inhalable particulate matter(PM10),on human lung adenocarcinoma A549 cells.Methods:The effects of MS PM10 on A549 cells,over different treatment durations were investigated in different groups:the 4-h group(4-h MS group and 4-h control group)and the 20-h group(20-h MS group and 20-h control group).Samples collected from the four groups were stored at
80C for subsequent digital gene expression analysis.The differentially expressed genes(DEGs),identified after PM10 treatment,were screened,and their expression patterns analyzed by cluster analysis,Gene Ontology term enrichment,and Kyoto Encyclopedia of Genes and Genomes pathway analysis.Results:Compared with two control groups,1109 DEGs were identified after 4 h of MS intervention and 3565 DEGs were found after 20 h of MS intervention,respectively.Compared with that after 4-h intervention,2149 DEGs were identified after 20-h intervention.Cluster analysis demonstrated that PM10 can significantly inhibit cell cycle process with the prolongation of intervention time.Significant pathway enrichment analysis showed that MS PM10 can inhibit A549 cell cycle process at all phases.When MS PM10 exposure time prolongs,the inhibitory effect on cell cycle process becomes more obvious.Conclusion:MS PM10 has many biological activities,and may cause differential expression of genes involved in various biological processes.Nevertheless,further research on MS is warranted for better understanding of the mechanistic details.

Effect of Juglone in qinglongyi on cell cycle status and apoptosis in A-549 cells

Objective To explore the inhibition of juglone in Qinglongyi on A-549 cells in vitro.Methods MTT assay was used.Laser confocal scanning microscope was used to observe apoptotic morphology.Changes of cell cycle are studied by flow cytometry analysis.Results MTT assay showed that juglone had a marked growth inhibition in A-549 cells and the IC50 is respectively 3.4×10-5 mol·L-1,1.8×10-5 mol·L-1 and 2.6×10-6 mol·L-1 after treatment for 24,48 and 72 h by juglone.Through Laser confocal scanning microscope,we can see that juglone can induce the apoptosis.Cell cycle changes are analyzed by flow cytometry with cells at G1 phase significantly less than those of control and cells at G2 phase significantly more than those of control.Conclusions It suggests that juglone could apoptosis of A-549 cells with the cell cycle arrest on G2 phase in distinct dose-dependent manner.

Oleanolic acid-induced apoptosis and its relation with intracellular calcium in human lung adenocarcinoma A549 cells

Objective To investigate the effect of oleanolic acid (OA) on apoptosis,correlation between apoptosis and intracellular calcium,and its mechanism in human lung adenocarcinoma cell line A549. Methods Human lung adenocarcinoma A549 cells were incubated in vitro and assigned with OA concentrations of 0,10,20 and 40μg/mL. The apoptosis status of A549 cell line was detected with Annexin V-FITC/PI by flow cytometry (FCM); fluorescence intensity (FI) of A549 cells was assessed and the level of intracellular calcium was calculated at 24 hour of OA intervention. The relation between apoptosis and calcium FI was illustrated by curve fitting. Results FCM showed that 10,20 and 40μg/mL of OA could induce A549 cell apoptosis,which followed a concentration-effect pattern; 24-hour intervention with 20μg/mL and 40μg/mL OA showed increased A549 cell apoptosis,and was significantly different from that with 0μg/mL OA (P<0.01). The FI of intracellular calcium concentration in 10,20 and 40μg/mL OA groups was significantly higher than that in 0μg/mL group after 24 hours’ intervention,and the FI showed a trend of increase with increased OA concentration (P<0.01). Curve fitting showed a significant correlation between apoptosis rate and intracellular calcium concentration in A549 cells (r=0.981,P<0.01). Regression equation was Y=0.508X-1.627. Conclusion OA plays a role in inducing apoptosis of human lung adenocarcinoma cells in a concentration-dependent manner. The OA-induced apoptosis is responsible for intracellular calcium overload of the tumor.

Inhibitory Effects of Natural Compound Alantolactone on Human Non-small Cell Lung Cancer A549 Cells

Alantolactone is a natural compound identified from the roots of Inula helenium L. that has multiple bio-activities. We examined its inhibitory effects on human non-small cell lung cancer（NSCLC） A549 cells. The an-tiproliferative effect of alantolactone on A549 cells was investigated via MTT[3′-（4,5dimethylthiazol-2-yl）-2,5- diphenyl tetrazolium bromide] assay and its apoptosis-inducing effect was determined by Hoechst staining and flow cytometry. We found that alantolactone significantly inhibited the proliferation of A549 cells and induced morphological changes typical for apoptosis. Flow cytometry analysis indicates dose-dependent cell cycle retardation at G0/G1 and S stages. The results indicate that alantolactone could be an attractive small-molecular natural compound for further development as a therapeutic drug against NSCLC.

Effect of hypoxia on migration, invasion and adhesion to endothelium of human pulmonary adenocarcinoma A549 cells

Objective： To evaluate the effect of hypoxia on migration, invasion and adhesion to endothelium of human pulmo- nary adenocarcinoma A549 cells. Methods： Wound-healing and Transwell invasion assays were performed to study the effect of hypoxia on migration and invasion of A549 cells, and A549 cells were added to a monolayer of human umbilical vein endo-thelial cells （HUVECs） to test the ability to adhere to endothelium. Immunofluorescence assay and luciferase reporter gene assay were also used to evaluate the effect of hypoxia on distribution of E-cadherin, β-catenin, and actin, and hypoxia-inducible factor-1 （HIF-1）-dependent transcription, respectively. Results： Hypoxia facilitated A549 cell migration, invasion, and A549 cell-endothelial cells adhesion, and modulated the distribution of E-cadherin and β-catenin, and actin cytoskeleton rearrange-ment, and up-regulated HIF-l-dependent reporter gene expression in A549 cells. Conclusion： Promotion ofA549 cell migration, invasion, and adhesion on endothelium by hypoxia might be modulated through its up-regulating HIF-l-dependent gene expression, which then induced the redistribution of E-cadherin and β-catenin, and the actin cytoskeletal reorganization.

Effects of paclitaxel on cell proliferation and apoptosis and its mechanism in human lung adenocarcinoma A549 cells

Objective： To investigate the effect of paclitaxel on cell proliferation and apoptosis of human lung adenocarcinoma A549 cells line and its mechanism in vitro. Methods ： Cell growth inhibition of paclitaxel on A549 cells was analyzed by MTT assay. Cell apoptosis was detected by DNA cytofluorometry, Hoechst33258 staining when treated with paclitaxel for 48 hours. Meanwhile, Cell cycle and apoptotic rate were analyzed by flow cytometry. The protein expressions of Bax and Bcl-2 were studied by Western Blot. Results： Paclitaxel inhibited the proliferation of A549 cells in a time-and dose-dependant manner. Hoechst33258 staining indicated that apoptosis was induced by paclitaxel. After treated for 48 hours, cell apoptosis rates of 25 nmo1/L, 50 nmol/L and 100 nmol/L paclitaxel groups were 11.52 ± 1.94% ,17.73 ±2.53%, and 29.32 ±5.51% respectively, which were significantly higher than those of control group 5.88 ±1.07%（all P 〈 0.01 ）, and apoptosis rate increased in dose-dependant manner. Meanwhile, G2/M stage cell percentage of 25 nmol/L, 50 nmol/L and 100 nmol/L paclitaxel groups were 42.52 ± 6.25%, 40.46 ± 5.81%, and 35.34 ±6.17% respectively,which were significantly higher than that of control group 22.32 ± 3.30%（all P 〈 0.01 ）; Western blot showed that paclitaxel increased the expression of Bax and decreased the expression of Bcl-2 in dose-dependant manner. Conclusion： Paclitaxel can inhibit A549 cell proliferation in a time-and dose-dependant manner. Its mechanism may be related to arresting cell cycle in G2/M stage and induce cell apoptosis by up-modulating Bax expression and down-modulating Bcl-2 expression.

Reversal effect of recombinant human Endostatin on cisplatin resistance in A549/DDP human lung adenocarcinoma cells in vitro

Objective： Recombinant human Endostatin （rh-Endostatin, YH-16） can reverse cisplatin resistance in A549/DDP cells. However, the possible effect of rh-Endostatin in reversing DDP-resistance in A549/DDP cells and the mechanism are needed to be investigated. Methods： Lung adenocarcinoma cell line A549 and its DDP-resistant cell line A549/DDP were treated with DDP and/or recombinant human Endostatin. Difference in drug resistance was analyzed between different regi- mens and between different cell lines after a 72 h-treatment in vitro. And below the non-cytotoxic concentration of rh-End- ostatin, the possibility of rh-Endostatin in reversing DDP-resistance in A549/DDP was evaluated. The resistance protein which was detected in the study included P glycoprotein （P-gp） and topoisomerase II （Topo-II）. Results： Rh-Endostatin below 400 IJg/mL showed no cytotoxicity in either A549 or A549/DDP after 72 h-treatment with it. The inhibited concentration of 50% （IC50） observed for DDP was （0.79 _＋ 0.05） IJg/mL in A549 and （13.2 ＋ 1.1） in A549/DDP respectively. IC50 was reduced to 2.57 ＋ 0.05 #g/mL in A549/DDP treated by rh-Endostatin below the non-cytotoxic concentrations in combination with DDP, with a reversal fold （RF） of 5.14 and a relative reversal rate of 85.6%. Apoptotic rates were 2.01%, 13.47% and 29.26% re- spectively for cells treated with rh-Endostain, DDP, and the combination. The rate of the A549/DDP control group was 0.99%. The expression level of P-gp or Topo-II was higher in A549/DDP cells than in A549 cells. Rh-Endostatin may partially reverse DDP-resistance in A549/DDP cells in vitro, with a probable mechanism related to lowering expression of P-gp and Topo-II. Conclusien： Rh-Endostatin of non-cytotoxic dose partially reversed cisptatin resistance in cisplatin-resistant human lung adenocarcinoma cell line A549/DDP. Rh-Endostatin reversed the resistance of A549/DDP cells to DDP, which may be related to decreased protein expression of P-gp and Topo-II in A549/DDP cells.

Inhibitory effect of toremifene monotherapy or combined with gemcitabine on A549 human lung adenocarcinoma cells

Objective： The aim of this study was to investigate the effect of toremifene on A549 human lung adenocarci- noma cells, and its sensibilization with gemcitabine, so that to provide a new clinical approach for non-small-cell lung cancer （NSCLC）. Methods： A549 cells were seeded into 96-well plates and exposed to different agents （gemcitabine or gemcitabine with toremifene）. The cytotoxicity of each agent was evaluated by MTT, cell cycle and apoptotic rate were detected by flow cytometry （FCM）. Results： 1. By using FCM, we found A549 cells in S and G2/M phases with toremifene decreased but increased in G0/G1 phase. The higher concentration of toremifene, the more decreased was when compared with the control group. 2. FCM showed toremifene＇s apoptosis effect on A549 cells increased with its increasing dose. 3. By MTT, toremifene had no cytotoxic effect on A549 cells at the concentration of 5 or 2.5 pmol/L. The IC5o of gemcitabine to A549 was 34.51 tJmol/L, and the combined group was 13.59 pmol/L. Conclusion： Toremifene could inhibit the growth of A549 human lung adenocarcinoma cells. Toremifene combined with gemcitabine showed significantly remarkable chemotherapy sensibilization on A549 human lung adenocarcinoma cells.

The Three Main SCFAs Inhibit the Inflammatory Response of A549 Cells Induced by Acinetobacter baumannii

Objective: The objective is to explore the mechanism of inhibitory effect of three main SCFAs (acetate, propionate and butyrate) on inflammatory response of A549 cells. Methods: Human lung adenocarcinoma cells (A549 cells) were cultured, and were divided into normal control group (NC group), A. baumannii infection group (A. baumannii group), NF-κB inhibitor group (JSH group), A. baumannii infection + sodium acetate group (NaAc group), A. baumannii infection + sodium propionate group (NaPc group) and A. baumannii infection + sodium butyrate group (NaB group). Real-time quantitative PCR was used to detect the mRNA expression of NLRP3, Caspase-1, IL-1β, IL-6, and TGF-β in A549 cells. Western blotting assay was used to determine the expression of autophagy and “pyroptosis” related proteins of NRLP3, cleaved-Caspase-1 (P20), GSDMD (P30), LC-3 and Beclin-1. At the same time, the expression of NF-κB p65 protein in nucleus and cytoplasm of A549 cells was detected. The level of reactive oxygen species in A549 cells was detected by flow cytometry. Results: Compared with A. baumannii group, the mRNA expression of NLRP3, IL-1β and IL-6 in NaAc group, NaPc group and NaB group decreased significantly, the mRNA expression of Caspase-1 in NaPc group and NaB group decreased significantly, only the mRNA expression of TGF-β in NaB group increased significantly;LC3-II expression increased significantly in NaPc group and NaB group, only Beclin-1 expression increased and GSDMD (p30) expression decreased significantly in NaB group. All three kinds of SCFAs could significantly inhibit the expression of cleaved-Caspase-1 (p20) after A. baumannii infection, but there was no significant change in the protein expression of NLRP3. Compared with NC group, the production of reactive oxygen species in A. baumannii group increased significantly at 3 h after A. baumannii infection. Compared with A. baumannii group, NaB could significantly suppress the production of reactive oxygen species induced by A. baumannii. Compared with A. baumannii group, the expression of NF-κB p65 in nucleus was significantly decreased and the expression of NF-κB p65 in cytoplasm was significantly increased after 24 h pre-incubation with NaB, NaPc and NaAc, respectively. Conclusion: A. baumannii can induce inflammatory injury of pulmonary epithelial cells, and the three major SCFAs can inhibit the activation of NLRP3 inflammasome and the release of pro-inflammatory factors through NF-κB/ROS/NLRP3 pathway, which provides a new way for clinical prevention of severe inflammatory injury caused by A. baumannii infection.

Patchouli alcohol induces autophagy in human lung adenocarcinoma cells A549 via increasing ratio of LC3 protein II/I and down-regulating p62

Objective:To study the patchouli alcohol(PA)-induced autophagy and proliferation inhibition of lung cancer A549 cells.Methods:the effects of PA at different concentrations on the proliferation and autophagy of A549 cells were detected by Cell Counting Kit-8(CCK-8)and electron microscopy,respectively.The A549 cells overexpressing LC3 gene were constructed by double luciferase lentiviral vector,and were treated with PA at half-inhibitory concentration(IC50)for 24 hours.Fluorescence microscopy was used to observe the fluorescence accumulation in cells.Western blot was used to detect the ratio of LC3 proteinⅡ/Ⅰ.Results:IC50 of PA on A549 cells for 24 h was 300μM.Treatment with 150μM and 300μM of PA for 24 h induced a cytoplasmic autophagic vesicle-like structure appearance in the cytoplasm of A549 cells,and the encapsulated cytoplasmic components were observed in those vesicles.150μM and 300μM of PA also elicited LC3 fluorescent protein accumulation(P<0.05).With the increased concentrations of PA,the ratios of LC3 proteinⅡ/Ⅰwere elevated(P<0.05),and the expressions of autophagy-related protein p62 were decreased gradually(P<0.05).Conclusion:PA can induce autophagy of lung cancer cells A549 by up-regulating the ratio of LC3 proteinⅡ/Ⅰand down-regulating p62 expression,which eventually inhibited the proliferation of lung cancer cells.

Effects of sotetsuflavone on expression of endostatin, TGF-β, STAT3, β-catenin and ZO-1 in non-small cell lung cancer A549 cells

Objective To investigate the effects of sotetsuflavone on endostatin, transforming growth factor-β （TGF-β）, signal transducers and activators of transcription 3 （STAT3）, β-catenin and zonula occludens-1 protein （ZO-1） in non-small cell lung cancer A549 cells. Methods： STAT3, β-catenin, TGF-β and ZO-1 mRNA expression were detected by real-time PCR. Endostatin and TGF-β expression were detected by immunofluorescence assay. STAT3 and β-catenin protein expression were detected by western blot. Results： Compared with the control group, TGF-β, STAT3 and β-catenin expression were down-regulated, endostatin and ZO-1 expression were up-regulated by sotetsuflavone. Simultaneously, it showed a significant concentration-dependent. Conclusion： The mechanism of action of sotetsuflavone in the treatment of lung cancer may be via inhibiting the expression of TGF-β, STAT3, and β-catenin, increasing the expression of endostatin and ZO-1, thereby exerting an anti-tumor effect.

Arctigenin attenuates paraquat-induced human lung epithelial A549 cell injury by suppressing ROS/p38 mitogen-activated protein kinases-mediated apoptosis

BACKGROUND:Paraquat(PQ)-induced acute lung injury(ALI)and pulmonary fi brosis are common diseases with high mortality but without eff ective antidotes in emergency medicine.Our previous study has proved that arctigenin suppressed pulmonary fibrosis induced by PQ.We wondered whether arctigenin could also have a protective eff ect on PQ-induced ALI.METHODS:A PQ-induced A549 cell injury model was used,and the effect of arctigenin was determined by a cell counting kit-8(CCK-8)cell viability assay.In addition,terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick-end labelling(TUNEL)staining assays and mitochondrial membrane potential assays were performed to evaluate the level of cell apoptosis.The generation of reactive oxygen species(ROS)was refl ected by dihydroethidium(DHE)staining and a 2’,7’-dichlorodihy drofluorescein diacetate(DCFH-DA)assay.Moreover,immunoblotting studies were used to assess the expression of mitogen-activated protein kinases(MAPKs)and p38 MAPK.RESULTS:Arctigenin attenuated PQ-induced inhibition of A549 cell viability in a dose-dependent manner.Arctigenin also significantly reduced PQ-induced A549 cell apoptosis,as refl ected by the TUNEL assay and mitochondrial membrane potential assay,which may result from suppressed ROS/p38 MAPK signaling because we found that arctigenin dramatically suppressed ROS generation and p38 MAPK phosphorylation.CONCLUSION:Arctigenin could attenuate PQ-induced lung epithelial A549 cell injury in vitro by suppressing ROS/p38 MAPK-mediated cell apoptosis,and arctigenin might be considered a potential candidate drug for PQ-induced ALI.

Highly Efficient Labeling of Human Lung Cancer Cells Using Cationic Poly-L-lysine-Assisted Magnetic Iron Oxide Nanoparticles

Cell labeling with magnetic iron oxide nanoparticles(IONPs)is increasingly a routine approach in the cellbased cancer treatment.However,cell labeling with magnetic IONPs and their leading effects on the biological properties of human lung carcinoma cells remain scarcely reported.Therefore,in the present study the magnetic c-Fe2O3nanoparticles(MNPs)were firstly synthesized and surface-modified with cationic poly-L-lysine(PLL)to construct the PLL-MNPs,which were then used to magnetically label human A549 lung cancer cells.Cell viability and proliferation were evaluated with propidium iodide/fluorescein diacetate double staining and standard 3-(4,5-dimethylthiazol-2-diphenyl-tetrazolium)bromide assay,and the cytoskeleton was immunocytochemically stained.The cell cycle of the PLL-MNPlabeled A549 lung cancer cells was analyzed using flow cytometry.Apoptotic cells were fluorescently analyzed with nuclear-specific staining after the PLL-MNP labeling.The results showed that the constructed PLL-MNPs efficiently magnetically labeled A549 lung cancer cells and that,at low concentrations,labeling did not affect cellular viability,proliferation capability,cell cycle,and apoptosis.Furthermore,the cytoskeleton in the treated cells was detected intact in comparison with the untreated counterparts.However,the results also showed that at high concentration(400 lg m L-1),the PLL-MNPs would slightly impair cell viability,proliferation,cell cycle,and apoptosis and disrupt the cytoskeleton in the treated A549 lung cancer cells.Therefore,the present results indicated that the PLL-MNPs at adequate concentrations can be efficiently used for labeling A549 lung cancer cells and could be considered as a feasible approach for magnetic targeted anti-cancer drug/gene delivery,targeted diagnosis,and therapy in lung cancer treatment.

Edaravone attenuates paraquat-induced lung injury by inhibiting oxidative stress in human type Ⅱalveolar epithelial cells

BACKGROUND:Edaravone(3-methyl-1-penyl-2-pyrazolin-5-one) is a potent free-radical scavenger and has the antioxidant ability to inhibit lipid peroxidation.The study aimed to examine the effect of edaravone on protecting the acute injury of human type II alveolar epithelial cells(A549cells) induced by paraquat(PQ) and the change of production of reactive oxygen species(ROS),malondialdehyde(MDA),superoxide dismutase(SOD).METHODS:A549 cells were cultured and divided into PQ group(group P),edaravone-treated group(group E) and normal control group(group C).The cells in group P were exposed to paraquat(600 umol/L),and the cells in group E were treated with edaravone(100 umol/L) additionally,and no drug intervention was given to the cells in group C.Real-time monitoring by LSCM was used to detect the cell response and the intracellular dynamic change of ROS level in A549 cells after administration of PQ and edaravone.And the levels of SOD and MDA were detected respectively by biochemistry colorimetry.Data were expressed as mean ± standard error of the mean.Statistical analysis was carried out with the soft SPSS 16.0.RESULTS:The concentration of intracellular ROS significantly increased when PQ was given to A549 cells.But after administration of edaravone,the concentration of intracellular ROS was decreased.Compared to the PQ group,the levels of SOD in the edaravone group were significantly increased while the levels of MDA were markedly decreased.CONCLUSIONS:Paraquat can increase the oxidative stress,and induce the lipid peroxidation of A549 cells.Edaravone has the effect to scavenge reactive oxygen species,and to protect against the PQ-induced lung toxicity.

Low Dose Hyper-radiosensitivity in Human Lung Cancer Cell Line A549 and Its Possible Mechanisms

The low dose hyper-radiosensitivity （HRS） in human lung cancer cell line A549 was investigated, the changes of ATM kinase, cell cycle and apoptosis of cells at different doses of radiation were observed, and the possible mechanisms were discussed. A549 cells in logarithmic growth phase were irradiated with ^60Co y-rays at doses of 0-2 Gy. Together with flow cytometry for precise cell sorting, cell survival fraction was measured by means of conventional colony-formation assay. The expression of ATM1981 Ser-P protein was examined by Western blot 1 h after radiation. Apoptosis was detected by Hoechst 33258 fluorescent staining, and Annexin V-FITC/PI staining flow cytometry 24 h after radiation. Cell cycle distribution was observed by flow cytometry 6, 12 and 24 h after radiation. The results showed that the expression of ATM1981Ser-P protein was observed at 0.2 Gy, followed by an increase at 〉0.2 Gy, and reached the peak at 0.5 Gy, with little further increase as the dose exceeded 0.5 Gy. Twenty-four h after radiation, partial cells presented the characteristic morphological changes of apoptosis, and the cell apoptosis curve was coincident with the survival curve. As compared with control group, the cell cycle almost had no changes after exposure to 0.1 and 0.2 Gy radiation （P〉0.05）. After exposure to 0.3, 0.4 and 0.5 Gy radiation, G2/M phase arrest occurred 6 and 12 h after radiation （P〈0.05）, and the ratio of G2/M phase cells was decreased 24 h after radiation （P〈0.05）. It was concluded that A549 cells displayed the phenomenon of HRS/IRR. The mode of cell death was mainly apoptosis. The activity of ATM and cell cycle change may take an important role in HRS/IRR.