Fangchinoline as a kinase inhibitor targets FAK and suppresses FAK-mediated signaling pathway in A549

Background: Fangchinoline as a novel anti-tumor agent has been paid attention in several types of cancers cells except lung cancer. Here we have investigated the effect of fangchinoline on A549 cells and its underlying mechanism.

Purpose: The purpose of this work was to study the effect of fangchinoline on A549 cells.

Methods: Four lung cancer cell lines (A549, NCI-H292, NCI-H446, and NCI-H460) were exposed to varying concentrations (10–40?μmol/l) of fangchinoline to observe the effect of fangchinoline on the four lung cancer cell lines and to observe the changes of the lung cancer cell on proliferation, apoptosis, and invasion.

Results: Fangchinoline effectively suppressed proliferation and invasion of A549 cell line but not NCI-H292, NCI-H446, and NCI-H460 cell lines by inhibiting the phosphorylation of FAK (Tyr397) and its downstream pathways, due to the significant differences of Fak expression between A549 and the other three cell lines. And all FAK-paxillin/MMP2/MMP9 pathway, FAK-Akt pathway, and FAK-MEK-ERK1/2 pathway could be inhibited by fangchinoline.

Discussion: Fangchinoline effectively suppressed proliferation and invasion of A549 cell line by inhibiting the phosphorylation of FAK (Tyr397) and its downstream pathways.

Conclusion: Fangchinoline could inhibit the phosphorylation of FAK^p-Tyr397, at least partially. Fangchinoline as a kinase inhibitor targets FAK and suppresses FAK-mediated signaling pathway and inhibits the growth and the invasion in tumor cells which highly expressed FAK such as A549 cell line.     

Decreased Biosynthesis of Lung Surfactant Constituent Phosphatidylcholine Due to Inhibition of Choline Transporter by Gefitinib in Lung Alveolar Cells

Purpose We investigated whether gefitinib, an anticancer agent, inhibits phosphatidylcholine (PC) biosynthesis and choline uptake by alveolar epithelial type II cells. Materials and Methods Uptake of choline and PC biosynthesis were examined in vitro, using human alveolar epithelia-derived cell line A549 and rat alveolar type (AT) II cells as models. Results Gefitinib reduced the incorporation of [³H]choline into PC in A549 and rat ATII cells. The uptake of [³H]choline by A549 and rat ATII cells was concentration-dependent, and the Km values were 15.0 and 10–100 μM, respectively. The uptake of [³H]choline by A549 and rat ATII cells was weakly Na⁺-dependent, and inhibited by hemicholinium-3. RT-PCR revealed expression of choline transporter-like protein (CTL)1 and organic cation transporter (OCT)3 mRNAs in both cells. The choline uptake by A549 and rat ATII cells was strongly inhibited by gefitinib with the IC₅₀ value of 6.77 μM and 10.5 μM, respectively. Conclusions Our results demonstrate that gefitinib reduces PC biosynthesis via inhibition of cellular choline uptake by A549 and rat ATII cells, which is mainly mediated by CTL1, resulting in abnormality of lung surfactant that can be one of mechanisms of the interstitial lung disease associated with gefitinib.     

The mechanisms of action of Tianhua™ on antitumor activity in lung cancer cells

Context: Tianhua (TH-R) is extracted from Trichosanthes kirilowii Maxim (Cucurbitaceae) containing trichosanthin, a traditional Chinese medicine, which has been locally reported to have good anticancer effects in vivo in both animal and human models. However, there have been several reports that trichosanthin has an anticancer effect involving apoptosis.

Objective: To investigate other anticancer effects of TH-R, various tumorigenesis parameters were verified.

Materials and methods: Telomerase activity, anti-apoptosis, anti-migration and immunomodulatory activity were estimated by telomeric repeat amplification protocol assay (TRAP), flow cytometry, Boyden chamber assay and ELISA assay, respectively.

Results: In our studies, we are the first to find that TH-R had a cytotoxic effect on lung cancer cells in MTS assays; it could change the cell cycle distribution of human lung cancer cells (A549 cell line) and induce apoptosis. Further anti-telomerase effects in human lung adenocarcinoma A549 cells using the TRAP assay were noted. TH-R also had an aggregation effect on peripheral blood lymphocytes, but no effect on stimulating peripheral lymphocytes to produce human interferon-γ(IFN-γ). TH-R could inhibit the migration, or metastatic ability, of A549 cells by Boyden chamber assay. In the oral feeding therapy of an in vivo mouse model, there was an initial inhibition of A549 cancer cell growth, but no statistical difference after one month of therapy.

Discussion and conclusion: It has been proven that medicinal herbs such as Tianhua have positive effects against cancer through preventing or inhibiting the process of lung tumorigenesis.     

Upregulation of Fas/Fas ligand-mediated apoptosis by gossypol in an immortalized human alveolar lung cancer cell line

Gossypol has wide antineoplastic effects in vitro, but its effects on human lung cancer have not been explored. To evaluate the activity of gossypol against alveolar cell lung cancer and to provide information on the mechanism of action, we examined the effects of gossypol on the proliferation of A549 cells indirectly using an XTT assay and on the distribution of cells within the phases of the cell cycle using flow cytometry. We also examined several factors that may affect apoptosis, including p53, p21/WAF1, Fas receptor, Fas ligand (FasL) and caspase 8 activity. The results showed that gossypol inhibited proliferation of A549 cells at a concentration of 0.5 micromol/L after 12 h treatment. The effect was both dose- and time-dependent by the induction of apoptosis without the effect of p53 and p21/WAF1. Upregulation of Fas/FasL, in association with the activation of downstream caspase 8 activity, was observed following treatment with gossypol. The Fas/FasL pathway accounted for 75% of gossypol-mediated apoptosis. We suggest that the Fas/FasL apoptotic system is the major pathway for gossypol-mediated apoptosis of A549 cells. Gossypol had no effect on the distribution of A549 cells within the phases of the cell cycle. In conclusion, gossypol inhibited A549 cells mainly by induction of the Fas/FasL apoptotic pathway, but not the p53 and p21/WAF1 pathway.     

Scorpion Peptide Smp24 Exhibits a Potent Antitumor Effect on Human Lung Cancer Cells by Damaging the Membrane and Cytoskeleton In Vivo and In Vitro

Smp24, a cationic antimicrobial peptide identified from the venom gland of the Egyptian scorpion Scorpio maurus palmatus, shows variable cytotoxicity on various tumor (KG1a, CCRF-CEM and HepG2) and non-tumor (CD34⁺, HRECs, HACAT) cell lines. However, the effects of Smp24 and its mode of action on lung cancer cell lines remain unknown. Herein, the effect of Smp24 on the viability, membrane disruption, cytoskeleton, migration and invasion, and MMP-2/-9 and TIMP-1/-2 expression of human lung cancer cells have been evaluated. In addition, its in vivo antitumor role and acute toxicity were also assessed. In our study, Smp24 was found to suppress the growth of A549, H3122, PC-9, and H460 with IC₅₀ values from about 4.06 to 7.07 µM and show low toxicity to normal cells (MRC-5) with 14.68 µM of IC₅₀. Furthermore, Smp24 could induce necrosis of A549 cells via destroying the integrity of the cell membrane and mitochondrial and nuclear membranes. Additionally, Smp24 suppressed cell motility by damaging the cytoskeleton and altering MMP-2/-9 and TIMP-1/-2 expression. Finally, Smp24 showed effective anticancer protection in a A549 xenograft mice model and low acute toxicity. Overall, these findings indicate that Smp24 significantly exerts an antitumor effect due to its induction of membrane defects and cytoskeleton disruption. Accordingly, our findings will open an avenue for developing scorpion venom peptides into chemotherapeutic agents targeting lung cancer cells.     

注射用黄芪多糖对耐顺铂人肺腺癌细胞A549/DDP耐药逆转作用研究

目的 探讨注射用黄芪多糖药物血清在体外对耐顺铂（DDP）人肺腺癌A549/DDP细胞株的耐药逆转作用。方法 通过建立小鼠肿瘤模型,运用血清药理学方法,以人肺腺癌敏感细胞A549和耐药细胞A549/DDP为研究对象,采用细胞毒实验（MTT）方法,探讨注射用黄芪多糖对耐顺铂人肺腺癌细胞A549/DDP的耐药逆转作用。结果 注射用黄芪多糖药物血清高、中、低剂量组分别与DDP合用时对A549/DDP细胞的耐药逆转倍数分别为1.24、1.41、1.34;且中、高剂量组与阳性对照DDP组比较差异有统计学意义（P＜0.05）。结论 注射用黄芪多糖能明显增加A549/DDP耐药细胞对DDP的敏感性,提高细胞死亡率,具有耐药逆转作用。     

LINC00094靶向miR-19b对非小细胞肺癌增殖、侵袭的抑制作用及其分子机制

目的 探讨LINC00094对非小细胞肺癌A549细胞增殖、凋亡、迁移、侵袭的影响及其作用机制。方法 将pcDNA3.1、pcDNA3.1-LINC00094、si-NC、si-LINC00094转染至非小细胞肺癌A549细胞中;将pcDNA3.1-LINC00094分别与miR-NC、miR-19b转染至A549细胞中,分别记为pcDNA3.1-LINC00094+miR-NC组、pcDNA3.1-LINC00094+miR-19b组。采用实时荧光定量PCR检测LINC00094和miR-19b表达水平;采用蛋白质印迹法检测细胞周期蛋白和凋亡蛋白表达水平;采用四甲基偶氮唑盐比色法、流式细胞术和Transwell分别检测细胞增殖、凋亡、迁移和侵袭能力;双荧光素酶报告实验检测LINC00094与miR-19b的靶向关系。结果 LINC00094在肺癌组织中低表达。过表达LINC00094可降低A549细胞的生存率,并抑制细胞迁移、侵袭（P<0.05）,且伴有相关蛋白表达水平的改变（P<0.05）。LINC00094靶向调控miR-19b,过表达miR-19b可逆转LINC00...     

miR-552通过PTEN/AKT信号通路促进非小细胞肺癌A549细胞的恶性生物学行为

目的 探讨miR-552通过调控PTEN/AKT信号通路促进人非小细胞肺癌A549细胞的恶性生物学行为及其相关机制。方法 通过qRT-PCR检测人肺癌组织样本和人非小细胞肺癌A549细胞系中miR-552、PTEN mRNA的表达情况;通过Western blotting检测PTEN、AKT、p-AKT蛋白的表达情况;通过CCK-8检测miR-552表达对A549细胞增殖能力的影响;通过Transwell小室检测miR-552表达对A549细胞迁移和侵袭能力的影响;通过流式细胞术检测miR-552表达对A549细胞凋亡能力的影响。结果 miR-552在肺癌组织和A549细胞中的表达显著上调。过表达miR-552可显著促进A549细胞的增殖、迁移和侵袭,并抑制细胞凋亡,而抑制其表达则结果相反。与癌旁组织相比,肺癌组织中PTEN表达显著下调。过表达miR-552可下调PTEN蛋白表达,上调p-AKT蛋白表达,对AKT蛋白无影响,而抑制其表达则结果相反。结论 miR-552可能通过PTEN/AKT信号通路促进人非小细胞肺癌A549细胞的恶性生物学行为。     

消岩汤对耐顺铂人肺腺癌A549/DDP细胞多药耐药基因调控作用的研究

目的 探讨具有"扶正解毒祛瘀"作用的中药复方消岩汤对耐顺铂人肺腺癌A549/DDP细胞多药耐药基因(MDR)的表达产物P糖蛋白(P-gP)及其mRNA表达水平的影响。方法 选择耐顺铂人肺腺癌A549/DDP细胞系作为获得性耐药模型,给予消岩汤含药血清,采用Western Blotting 免疫印迹法及RT-PCR技术检测MDR的表达产物P-gP的含量及其mRNA表达水平。结果 与对照组比较,随着消岩汤含药血清药物浓度的增加,P-gP蛋白表达逐渐减弱(P<0.05);与对照组比较,经不同浓度消岩汤含药血清作用后,A549/DDP细胞中的MDR1基因的mRNA水平均有所下降(P<0.05),且随着药物浓度的增加,基因表达抑制作用越明显。结论 消岩汤逆转肺癌耐药的可能机制为通过抑制细胞膜上P-gP及其基因的表达而阻止细胞对顺铂的输出,从而聚集细胞内的药物浓度达到有效逆转肺癌耐药的效果。     

基于RNA干扰技术探讨消岩汤对肺腺癌A549细胞凋亡的影响

目的 分析消岩汤干预下sh-survivin对人肺腺癌A549细胞增殖及凋亡的影响。方法 选择人肺腺癌A549细胞, 采用中药复方进行干预及shRNA进行转染, 将转染后的细胞分组, 通过MTT法观察消岩汤对A549细胞生长的影响, 免疫组化法检测survivin蛋白的表达, 流式细胞仪检测细胞凋亡率。结果 消岩汤能有效地抑制人肺腺癌A549的细胞增殖, 运用消岩汤作用细胞24 h后, 侵袭的细胞数明显减少, 该方作用48 h后可以诱导肿瘤细胞凋亡;消岩汤中剂量组与转染sh-survivin组抑制率相当, 不同剂量的消岩汤均可协同sh-survivin使肺癌细胞凋亡率增加。结论 消岩汤可以通过干预肿瘤细胞凋亡抑制蛋白的表达而有效抑制肿瘤的发展。     

Glossogin, a novel phenylpropanoid from Glossogyne tenuifolia, induced apoptosis in A549 lung cancer cells

Glossogyne tenuifolia has been shown to exhibit good antioxidant and anticancer activity. In this study, a new phenylpropanoid compound, glossogin (1′-acetoxy-4-O-isovalyryleugenol), was isolated from ethyl acetate extract of G. tenuifolia by using column chromatography and HPLC. Its chemical structure was determined by ¹H and ¹³C NMR, MS and IR spectroscopic evidence. This compound showed the cytotoxicity against A549 human lung cancer cell line and it induced the progressing apoptosis on A549 cells. This apoptosis was verified as A549 cells were arrested at the sub-G₁ phase. The apoptosis was accompanied by release of cytochrome C and activation of caspase-9 and -3. It was also associated with the decrease in Bcl-2 and Bcl-xL protein levels, and the increase in Bad protein expression. Data analysis suggests glossogin exerted significant apoptotic effect on A549 cells through the mitochondrial pathway. Hence, our findings showed that glossogin exhibited potential anticancer activity against lung cancer through proliferating inhibition and apoptosis induction of cancer cells.     

Mitochondria are involved in stress response of A549 alveolar cells to halothane toxicity.

During inhalation anaesthesia lung epithelial cells are directly exposed to halogenated hydrocarbons such as halothane. Information about the effects of volatile anaesthetics on lung cells is rather limited although their noxious effect on the A549 alveolar cells has been shown recently. The present study indicated that halothane decreases cell viability, impairs DNA integrity and provokes stress-induced apoptosis in A549 cells when applied at clinically relevant concentrations. Data obtained clearly demonstrated intensive expression of anti-apoptotic Bcl-2 protein during treatment with all tested concentrations. In post-treatment periods the increased DNA injury was accompanied by reduction of Bcl-2 expression. We concluded that the in vitro effect of halothane on lung cells involved alteration in the expression of proteins of the mitochondrial apoptotic pathway.     

Propyl gallate decreases the proliferation of Calu-6 and A549 lung cancer cells via affecting reactive oxygen species and glutathione levels

Propyl gallate (3,4,5-trihydroxybenzoic acid propyl ester, PG) has an anti-proliferative effect in various cells. In this study, Calu-6 and A549 lung cancer cells were used to examine the anti-proliferative effect of PG in relation to reactive oxygen species (ROS) and glutathione (GSH) levels. PG (100–1,600 μM) dose-dependently inhibited the proliferation of Calu-6 and A549 cells at 24 h, and PG at 800–1,600 μM strongly induced cell death in both cell lines. PG (800–1,600 μM) increased cellular metabolism in Calu-6 but not A549 cells at 4 h. PG either increased or decreased ROS levels, including O₂˙⁻ and ˙OH, depending on the incubation doses and times of 1 or 24 h. Even these effects differed between Calu-6 and A549 cell types. PG reduced the activity of superoxide dismutase (SOD) in Calu-6 cells, and it augmented the activity of catalase in A549 cells. PG dose-dependently increased the number of GSH depleted cells in both Calu-6 and A549 cells at 24 h. In addition, PG decreased GSH levels in both lung cancer cells at 1 h. Furthermore, diethyldithiocarbamate (DDC; an inhibitor of SOD) and 3-amino-1,2,4-triazole (AT; an inhibitor of catalase) differently affected cellular metabolism, ROS and GSH levels in PG-treated and PG-untreated Calu-6 and A549 cells at 1 h. In conclusion, PG dose-dependently decreased the proliferation of Calu-6 and A549 lung cancer cells, which was related to changes in ROS levels and the depletion of GSH.     

Effect of glutathione combined with cisplatin and oxaliplatin on the proliferation and apoptosis of lung carcinoma cell line

Reduced glutathione (GSH) is generally administered for patients with cancer to reduce the side-effects of anti-cancer drugs. However, whether its protective effects interfere with anti-carcinogenicity is still unclear. The aim of this study was to investigate the effect of exogenous GSH on effects of oxaliplatin (L-OHP) or cisplatin (CDDP) by observing the proliferation and apoptosis of lung carcinoma cell line A549. Cell proliferation was evaluated by sulforhodamine-B assay and morphological changes were observed by an inverted microscope. Cell cycle distribution and apoptosis rate were observed by flow cytometry (FCM). Results showed that GSH did not change the inhibiting effects of L-OHP and CDDP on A549 proliferation, and did not reduce the apoptosis induced by CDDP. The FCM analysis showed the GSH combined with the CDDP group had fewer cells in the S-phase and had an apoptotic peak, which was not significantly different from that of the CDDP alone group (p?>?0.05). These results indicated that GSH does not reduce the effects of L-OHP and CDDP to inhibit A549 growth in vitro, and doesn’t affect the apoptosis induced by CDDP.     

福多司坦对肺癌细胞黏蛋白MUC1和MUC5AC的抑制作用研究

目的 探讨黏痰溶解剂福多司坦对肺癌细胞高表达的黏蛋白MUC1和MUC5AC的调控作用。方法 首先采用分子对接技术将福多司坦、原配体和阳性药与MUC1和MUC5AC蛋白进行对接，初步得到福多司坦、原配体及阳性药与靶蛋白的结合能与分子-蛋白相互作用活性对接口袋。然后采用体外PCR与ELISA从细胞层面探讨不同浓度福多司坦对TNF-a诱导的高表达MUC1和MUC5AC的调控作用。结果 分子对接结果显示福多司坦与MUC1和MUC5AC均能自发结合，并且福多司坦与MUC1的结合比MUC5AC更为紧密。细胞试验表明，不同浓度福多司坦(1~10 mmol·L^–1)可以降低肺癌A549细胞在TNF-a刺激下引起的MUC1和MUC5AC的高表达，也可降低NCI-H292细胞在TNF-a刺激下引起的MUC1的高表达。首次发现福多司坦能阻断肺癌细胞A549的MUC1蛋白表达，并且对MUC1蛋白的抑制呈现浓度依赖性。结论 福多司坦可抑制A549细胞黏蛋白MUC5AC和MUC1的表达，也可抑制NCI-H292细胞黏蛋白MUC1的表达，为进一步研究对肺癌细胞转移和侵袭的干预作用以及辅助肺黏液型肺癌患者的临床治疗提供理论依据。     

峨参石油醚提取物对肺癌细胞A549和H460增殖的抑制作用观察

目的探讨不同浓度的峨参石油醚提取物对体外培养的人肺癌细胞A549、H460的增殖及凋亡的抑制作用。方法不同浓度的峨参石油醚提取物作用于肺癌细胞A549和H460,48 h后MTT法观察药物对肺癌细胞A549和H460生长的抑制效应;用倒置显微镜观察细胞形态学的改变,应用DAPI染色法观察不同浓度峨参石油醚提取物作用于癌细胞24 h后对细胞凋亡的影响。结果峨参石油醚提取物对肺癌细胞A549和H460的半数有效抑制浓度IC50值分别为6.13μg/ml和0.97μg/ml;通过倒置显微镜可观察到细胞的形态学改变,细胞荧光染色出现了明显的凋亡细胞,表现为细胞生长明显受到抑制,荧光增加,有明显的细胞核断裂和皱缩。结论 峨参石油醚提取物对肺癌细胞增殖具有明显的抑制及诱导凋亡的作用。     

Enhanced cell death effects of MAP kinase inhibitors in propyl gallate-treated lung cancer cells are related to increased ROS levels and GSH depletion

Propyl gallate (PG) has an anti-growth effect in lung cancer cells. The present study investigated the effects of mitogen-activated protein kinase (MAPK; MEK, JNK, and p38) inhibitors on PG-treated Calu-6 and A549 lung cancer cells in relation to cell death as well as reactive oxygen species (ROS) and glutathione (GSH) levels. PG induced cell death in both Calu-6 and A549 lung cancer cells at 24 h, which was accompanied by loss of mitochondrial membrane potential (MMP; ΔΨ_m). All of the tested MAPK inhibitors increased cell death in both PG-treated lung cancer cell lines. In particular, MEK inhibitor strongly enhanced cell death and MMP (ΔΨ_m) loss in PG-treated Calu-6 cells and p38 inhibitor had the same effects in A549 cells as well. PG increased ROS levels and caused GSH depletion in both cell lines at 24 h. MAPK inhibitors increased O₂^•- levels and GSH depletion in PG-treated Calu-6 cells, and JNK and p38 inhibitors increased ROS levels and GSH depletion in PG-treated A549 cells. In conclusion, MAPK inhibitors increased cell death in PG-treated Calu-6 and A549 lung cancer cells. Enhanced cell death and GSH depletion in Calu-6 cells caused by the MEK inhibitor were related to increased O₂^•- levels, and the effects of the p38 inhibitor in A549 cells were correlated with increased general ROS levels.     

α-Conotoxin ImI-modified polymeric micelles as potential nanocarriers for targeted docetaxel delivery to α7-nAChR overexpressed non-small cell lung cancer

A micelle system modified with α-Conotoxin ImI (ImI), a potently antagonist for alpha7 nicotinic acetylcholine receptor (α7-nAChR) previously utilized for targeting breast cancer, was constructed. Its targeting efficiency and cytotoxicity against non-small cell lung cancer (NSCLC) highly expressing α7-nAChR was investigated. A549, a non-small cell lung cancer cell line, was selected as the cell model. The cellular uptake study showed that the optimal modification ratio of ImI on micelle surface was 5% and ImI-modification increased intracellular delivery efficiency to A549 cells via receptor-mediated endocytosis. Intracellular Ca²⁺ transient assay demonstrated that ImI modification led to enhanced molecular interaction between nanocarriers and A549 cells. The in vivo near-infrared fluorescence imaging further revealed that ImI-modified micelles could facilitate the drug accumulation in tumor sites compared with non-modified micelles via α7-nAChR mediation. Moreover, docetaxel (DTX) was loaded in ImI-modified nanomedicines to evaluate its in vitro cytotoxicity. As a result, DTX-loaded ImI-PMs exhibited greater anti-proliferation effect on A549 cells compared with non-modified micelles. Generally, our study proved that ImI-modified micelles had targeting ability to NSCLC in addition to breast cancer and it may provide a promising strategy to deliver drugs to NSCLC overexpressing α7-nAChR.     

Lipopolysaccharide induces apoptotic insults to human alveolar epithelial A549 cells through reactive oxygen species-mediated activation of an intrinsic mitochondrion-dependent pathway

Alveolar type II epithelial cells can regulate immune responses to sepsis-induced acute lung injury. Lipopolysaccharide (LPS), an outer membrane component of Gram-negative bacteria, can cause septic shock. This study was designed to evaluate the cytotoxic effects of LPS on human alveolar epithelial A549 cells and its possible molecular mechanisms. Exposure of A549 cells to LPS decreased cell viability in concentration- and time-dependent manners. In parallel, LPS concentration- and time-dependently induced apoptosis of A549 cells. Meanwhile, LPS only at a high concentration of 10 μg/ml caused mildly necrotic insults to A549 cells. In terms of the mechanism, exposure of A549 cells to LPS increased the levels of cellular nitric oxide and reactive oxygen species (ROS). Pretreatment with N-acetylcysteine (NAC), an antioxidant, significantly lowered LPS-caused enhancement of intracellular ROS in A549 cells and simultaneously attenuated the apoptotic insults. Sequentially, treatment of A549 cells with LPS caused significant decreases in the mitochondrial membrane potential and biosynthesis of adenosine triphosphate. In succession, LPS triggered the release of cytochrome c from the mitochondria to the cytoplasm. Activities of caspase-9 and caspase-6 were subsequently augmented following LPS administration. Consequently, exposure of A549 cells induced DNA fragmentation in a time-dependent manner. Pretreatment of A549 cells with NAC significantly ameliorated LPS-caused alterations in caspase-9 activation and DNA damage. Therefore, this study shows that LPS specifically induces apoptotic insults to human alveolar epithelial cells through ROS-mediated activation of the intrinsic mitochondrion–cytochrome c-caspase protease mechanism.