ANTP-SMACN7 fusion peptide alone induced high linear energy transfer irradiation radiosensitization in non-small cell lung cancer cell lines

Objective: The aim of the present study was to investigate the mechanisms responsible for the radiation-sensitizing effect of antennapedia proteins, ANTP-SMACN7, on lung cancer cells treated with accelerated carbon and Fe particle irradiation.Methods: The ANTP-SMACN7 fusion peptide was synthesized and linked to fluorescein isothiocyanate to determine its ability to penetrate cells. A549 and NCI-H460 cells, human non-small cell lung cancer(NSCLC) cell lines, were irradiated with X-ray or high lin...     

TRAIL, FasL and a blocking anti-DR5 antibody augment paclitaxel-induced apoptosis in human non-small-cell lung cancer.

Lung carcinoma is one of the most frequent causes of malignancy-related mortality in the world. Paclitaxel (PA) is an antineoplastic agent used in the treatment of non-small-cell lung cancer (NSCLC) and possesses a single-agent response rate approaching 25%. PA kills tumor cells by inducing both cellular necrosis and apoptosis. Fas and Trail receptors (DR4 and DR5) are TNF family members and act as death signal transduction proteins in the apoptosis cascade. Despite the importance of PA in lung cancer treatment, the function of Fas, DR4 and DR5 in PA-induced apoptosis, as well as the effect of their respective ligands FasL and TRAIL alone or in combination with PA, remains poorly understood. We show here that 10 microM PA induces a significant 10- to 57-fold increase in primary lung cancer cell apoptosis and is associated with 20-215% increases in caspase-3 activity in various NSCLC cell types. All the lung cancer cells express Fas, FasL, DR4 and DR5; however PA did not significantly modify their levels. We provide here the first time evidence that TRAIL is a potent inducer of apoptosis in multiple NSCLC cell lines. Noticeably, CH11, the Fas receptor cross-linking and the antagonistic anti-DR5 antibody enhance considerably the spontaneous apoptotic rate in 3 out of 5 cell types. The combination treatments, FasL+PA, TRAIL+PA or PA+anti-DR5 antibody, greatly enhance PA-apoptotic effect in most cell lines. These data suggest that the use of new combination treatment with PA and ligands targeting Fas or TRAIL receptors would be particularly efficacious.     

Chemotherapy triggers apoptosis in a caspase-8-dependent and mitochondria-controlled manner in the non-small cell lung cancer cell line NCI-H460

Chemotherapy-induced apoptosis is generally thought to be dependent on a pathway headed by caspase-9. This model is primarily based on studies performed in leukemia cells; however, little is known about caspase cascades in relatively resistant solid tumor cells, including non-small cell lung cancer (NSCLC) cells. Using the NSCLC cell line NCI-H460 (H460), here, we studied the effect of stable expression of various caspase inhibitors on apoptosis induced by the anticancer drugs cisplatin, topotecan, and gemcitabine. Interestingly, overexpression of caspase-9S and X-linked inhibitor of apoptosis (XIAP), both able to inhibit caspase-9 activity, failed to block apoptosis. In contrast, stable expression of caspase-8 inhibitors, such as cytokine response modifier A (CrmA) and dominant-negative caspase-8, almost completely abrogated apoptosis and also enhanced clonogenic survival. Caspase-8 activation in H460 cells was not mediated by death receptors, inasmuch as overexpression of dominant-negative Fas-associated death domain (FADD-DN) did not prevent procaspase-8 cleavage and subsequent apoptosis. However, stable expression of Bcl-2 and Bcl-xL did suppress these apoptotic events, including the release of cytochrome c from mitochondria, which was observed in drug-treated H460 cells. In the NSCLC cell line H460, we, thus, provide evidence for the existence of a novel drug-inducible apoptotic pathway in which activation of caspase-8, and not of caspase-9, forms the apical and mitochondria-dependent step that subsequently activates the downstream caspases.     

Activation of caspase-3 and cleavage of Rb are associated with p16-mediated apoptosis in human non-small cell lung cancer cells

The p16 tumor suppressor gene is frequently inactivated in human cancer tissues and cell lines. We previously reported that wild-type p16 expression from an adenovirus vector (Adv/p16) induced p53-dependent apoptotic cell death in non-small cell lung cancer (NSCLC) cell lines. Here we show the potential mechanism of apoptosis induced by Adv/p16 infection. Infection of human NSCLC cell line A549, which carries the wild-type p53 gene, with Adv/p16 resulted in activation of caspase-3, accompanied by the cleavage of its substrate poly (ADP-ribose) polymerase (PARP), on day 3 of infection. The retinoblastoma (Rb) cell cycle regulator protein was also cleaved after activation of caspase-3; when the levels of Rb significantly diminished, apoptosis began. When A549 cells were pretreated with the caspase-inhibitory peptide N-acetyl-asp-Glu-Val-Asp-CHO (aldehyde) (Ac-DEVD-CHO), Adv/p16-mediated apoptosis and Rb cleavage were greatly inhibited. Furthermore, MDM2, a negative regulator of p53 expression was upregulated 3 days after Adv/p16 infection, and MDM2 was subsequently cleaved by caspase-3; MDM2 cleavage was inhibited by Ac-DEVD-CHO treatment. These data implied that cleavage of Rb, in addition to activation of caspase-3, represented a mechanism by which Adv/p16 induced apoptotic cell death in human NSCLC cells. Our results support the clinical relevance of Adv/p16 as a treatment for p16-null human NSCLC that express wild-type p53.     

Aurora-A激酶在人类不同肺癌细胞株中的表达

背景与目的近年来的研究发现Aurora-A在多种恶性肿瘤中高表达。本研究检测Aurora-A激酶在人类不同肺癌细胞株中的表达及其与DNA含量的关系,旨在寻找肺癌新的分子治疗靶点和肿瘤标记物,为指导肺癌个性化治疗提供一种新的方法。方法应用RT-PCR与Westernblot方法检测PG(高转移的巨细胞肺癌)、A549(肺腺癌)、NCI-H460(大细胞肺癌)3种肺癌细胞株Aurora-A的表达;流式细胞仪检测3种肺癌细胞DNA含量(四倍体及多倍体),分析Aurora-A的表达与DNA含量的相关性。结果半定量RT-PCR电泳结果显示,A549、PG、NCI-H460中Aurora-A/β-actin比值分别为1.16、1.14、0.84;Westernblot结果在A549、PG与NCI-H460中的Aurora-A/β-actin比值分别为21.13、8.96与6.43,提示3种肺癌细胞Aurora-A均呈高表达。A549、PG、NCI-H460细胞含有四倍体的细胞比例分别为14.97%、19.88%和10.60%,三者有显著性差异(P<0.01);其多倍体(>4N)的细胞比例分别为3.59%、2.66%、2.30%。提示Aurora-A表达强弱与肺癌细胞多倍体的比例高低有相关性。结论3种肺癌细胞中Aurora-A基因均高表达,其表达水平在不同肺癌细胞株中存在差异。     

p53 enhances gefitinib-induced growth inhibition and apoptosis by regulation of Fas in non-small cell lung cancer

Treatment with gefitinib, a specific inhibitor of epidermal growth factor receptor tyrosine kinase (EGFR-TK), has resulted in dramatic responses in some patients with non-small cell lung cancer (NSCLC). Most patients who respond to gefitinib have EGFR-TK mutations; however, >10% of patients with EGFR-TK mutations do not respond. Similarly, some patients without EGFR-TK mutations respond to this drug, suggesting that other factors determine sensitivity to gefitinib. Aberrations of the tumor suppressor gene p53 are frequently associated with drug resistance. In this study, we investigated the role of p53 in growth-inhibitory and apoptotic effects of gefitinib in the human NSCLC cell lines NCI-H1299 and A549, which have no EGFR-TK mutations. NCI-H1299 cells, which had a p53-null genotype, were more resistant to gefitinib compared with A549 cells, which were wild-type p53 (IC(50), 40 micromol/L in NCI-H1299 and 5 micromol/L in A549). Treatment of A549 with gefitinib resulted in the translocation of p53 from cytosol to nucleus and the up-regulation of Fas, which was localized to the plasma membrane. In the stable H1299 cell line with tetracycline-inducible p53 expression, induced p53 enhanced growth inhibition and apoptosis by gefitinib through the up-regulation of Fas and restoration of caspase activation. A caspase inhibitor, Z-VAD-fmk, reduced these effects. Conversely, inhibition of p53 using antisense oligonucleotide in A549 caused a significant decrease in apoptosis by gefitinib and down-regulation of Fas under the same conditions. In conclusion, p53 may play a role in determining gefitinib sensitivity by regulating Fas expression in NSCLC.     

Increased inducible nitric oxide synthase in lung carcinoma of smokers

BACKGROUND: Cigarette smoking is well known to play an important role in the development of lung cancer. Inducible nitric oxide synthase (iNOS) can either promote or inhibit cell proliferation and growth, which makes its role in the development of malignant tumors controversial. The relation between cigarette smoking and iNOS in human lung cancer is unknown. METHODS: The study examined the levels of iNOS/NO in nonsmall-cell lung cancer (NSCLC) tissues of smokers and nonsmokers and in NSCLC cells (NCI-H23) treated by 4-(N-Methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a potent tobacco-specific carcinogen. RESULTS: The level of iNOS/NO was significantly higher in lung cancer tissues of smokers than that of nonsmokers. Unlike iNOS/NO, the activity of caspase-3 was reduced in the former compared with the latter. The expression of the cleaved caspase-3 was deceased in NCI-H23 cells treated with S-Nitroso-N-acetylpenicillamine (SNAP), an NO donor, whereas treatment with NG-methyl-L-arginine (NMA), an NO inhibitor, caused an increase in cleaved caspase-3. Consistent with the change in caspase-3, SNAP treatment inhibited cell death induced by UCN01, a potent cell death-inducer. NMA treatment greatly enhanced the sensitivity of the cells to UCN01. Further, the cells treated by NNK showed an increase in iNOS protein, accompanied by an elevation of cell proliferation. CONCLUSIONS: The study demonstrates that cigarette smoking promotes the level of iNOS/NO but suppresses the activity of caspase-3, which may lead to the proliferation and growth of lung cancer cells.     

血管内皮钙黏蛋白对非小细胞肺癌侵袭转移的影响及其作用机制

目的 探讨非小细胞肺癌（non-small cell lung cancer, NSCLC）组织中血管内皮钙黏蛋白（vascular endothelial cadherin, VE-cadherin）的表达和其对细胞侵袭迁移能力的影响及作用机制。方法 采用免疫组织化学、RT-PCR法检测VE-cadherin在人NSCLC组织和癌旁组织中的表达;Westernblot法检测VE-cadherin在NSCLC细胞株中的表达;Transwell实验检测VE-cadherin对NCI-H460细胞侵袭迁移能力的影响;免疫荧光检测VE-cadherin与P120ctn在NCI-H460细胞上的定位;免疫共沉淀检测VE-cadherin与P120ctn的连接情况。结果 VE-cadherin在肺癌组织中表达水平较癌旁组织上调,其表达与NSCLC有无吸烟史、有无淋巴结转移有关（P<0.05）。VE-cadherin在PG、NCI-H460、 A549细胞株表达水平不同,干扰VE-cadherin表达后,NCI-H460细胞侵袭迁移能力下调,低氧可诱导VEcadherin在NCI-H460细胞表达增强,VE-cadherin与P120ctn存在结构上的连接。结论 VE-cadherin可能通过缺氧信号活化及P120ctn介导参与NSCLC侵袭、转移。     

2-Deoxy-d-glucose and ferulic acid modulates radiation response signaling in non-small cell lung cancer cells

Previously, we reported the radiosensitizing potential of the combination of 2-deoxy-d-glucose (2DG) and ferulic acid (FA) in NCI-H460 non-small cell lung carcinoma cells in vitro. The present study aims to explore the relevant mechanism of cell death induced by the combination of 2DG and FA along with irradiation in NCI-H460 cells. Incubation of NCI-H460 cells with the combination of 2DG and FA for 24 h before irradiation upregulated the expression of proapoptotic proteins p53 and Bax. Combination of 2DG and FA also increased the levels of p21 and GADD45A in NCI-H460 cells. DNA repair inhibition is expected to be a possible mechanism for the radiosensitization observed, which is evidenced by the downregulation of radiation-induced ataxia-telangiectasia mutated gene expression upon treatment with 2DG and/or FA. Moreover, Western blotting analysis of NF-κB and caspase-3 revealed the involvement of apoptotic signals in the cytotoxicity exhibited by the combination of 2DG and FA. Cell cycle analysis data also showed the increased percentage of Sub-G₀ phase cells upon treatment with the combination of 2DG and FA before irradiation. Taken together, the results of our study clearly suggested that the cell death induced by the combination of 2DG and FA along with irradiation would involve alteration in expression of p53, p21, NF-κB, Bax, and caspase-3, indicating oxidative mechanism in NCI-H460 cells.     

Slp2反义真核表达载体的构建及功能研究

背景与目的 肺癌相关基因的研究一直是研究的热门课题，S1p2基因是通过cDNA微阵列技术筛选出的肺癌差异表达基因之一，本研究旨在对S1p2基因在肺癌细胞系中的表达及其功能进行初步研究。方法 提取肺癌细胞系A549、GLC-82、NCI-H446、NCI-H460的细胞总RNA，用RT-PCR方法检测肺癌细胞系中S1p2基因mRNA水平的表达；构建S1p2反义基因，通过离子脂质体将克隆的S1p2反义基因导入肺癌细胞系GLC-82、NCI-H446、NCI-H460，用半定量RT-PCR检测转染目的基因对肺癌细胞系S1p2表达的影响；通过四唑盐比色法绘制细胞生长曲线以及流式细胞分析、软琼脂细胞克隆形成试验，观测转染S1p2反义基因对肺癌细胞系GLC-82、NCI-H446、NCI-H460生长速度、细胞周期以及细胞增殖能力的影响。结果 在4个肺癌细胞系中，S1p2基因均为阳性表达；转染S1p2反义基因后的肺癌细胞系GLC-82、NCI-H446、NCI-H460的细胞生长速度明显减慢；在流式细胞分析直方图上表现为G2期的细胞增多，并曾在转染目的基因的NCI-H446细胞流式直方图中观察到了位于G0／G1期左侧的“亚Gt峰”的出现；转染S1p2反义基因后肺癌细胞系的软琼脂培养细胞克隆形成率明显低于未转染细胞。结论 S1p2基因与肺癌细胞的生长、增殖力密切相关，有必要进行深入研究和探讨。     

Metuzumab enhanced chemosensitivity and apoptosis in non-small cell lung carcinoma

Targeted therapeutics is used as an alternative treatment of non-small cell lung cancer (NSCLC); however, treatment effect is far from being satisfactory, and therefore identification of new targets is needed. We have previously shown that metuzumab inhibit tumor growth in vivo. The present study was performed to investigate the anti-tumor efficacy of metuzumab combined with gemcitabine and cisplatin (GP), paclitaxel and cisplatin (TP) or navelbine and cisplatin (NP) regimens in multiple NSCLC cell lines. Our results demonstrate that, in comparison to single agent metuzumab or GP treated cells, metuzumab combined with GP display inhibitory effects on tumor growth. Furthermore, we found that metuzumab elevated the sensitivity of cell lines to gemcitabine, which was identified by MTT assay. Flow cytometric analysis showed that metuzumab combined with gemcitabine (GEM) treatment led to an obvious G1 arrest and an elevated apoptosis in A549, NCI-H460 and NCI-H520 cells. Western blot analysis also demonstrated a significantly reduced level of cyclin D1, Bcl-2, and an obviously increase level of Bax and full-length caspase-3 in A549, NCI-H460 and NCI-H520 cells treated with metuzumab/gemcitabine combination in comparison with single agent treated cells. In addition, metuzumab/gemcitabine treated A549, NCI-H460 and NCI-H520 cells also demonstrated a significantly increase in deoxycytidine kinase (dCK) protein level compared with single agent metuzumab or gemcitabine treated cells. Xenograft models also demonstrated that this metuzumab/gemcitabine combination led to upregulation of dCK. Taken together, the mechanisms of metuzumab combined with GP repress tumor growth were that the combined treatment significantly inhibited the tumor cell proliferation, apoptosis and cell cycle in vitro and in vivo and at least partially by induction of dCK expression. Our results suggested that metuzumab could significantly enhance chemosensitivity of human NSCLC cells to gemcitabine. Metuzumab/gemcitabine combination treatment may be a potentially useful therapeutic regimen for NSCLC patients.     

Bufotalin sensitizes death receptor-induced apoptosis via Bid- and STAT1-dependent pathways

Tumor necrosis factor-alpha (TNF-α) and TNF-related apoptosis-inducing ligand (TRAIL) are apoptosis-inducing ligands that stimulate death receptors. In this study, we investigated the effects of bufotalin, a major compound in toad venom, on sensitizing TNF-α and TRAIL-induced apoptosis of HeLa cells. Bufotalin promoted death receptor-mediated cell death, especially TRAIL-induced apoptosis, through activation of caspase-3 and PARP-1. Mitochondrial Bid-dependent pathway was activated in TNF-α-induced cell death. Cotreatment of bufotalin with TRAIL resulted in the downregulation of anti-apoptotic proteins, including Bcl-XL, Mcl-1, survivin and XIAP, and the up-regulation of MAPKs and TRAIL receptor DR5. In addition, phosphorylation of STAT1 was strongly inhibited by bufotalin. Moreover, DR5 expression was induced by knocking down the STAT1 expression. Moreover, the TRAIL-induced apoptotic response was promoted by STAT1 siRNA. Our results demonstrated that bufotalin is a powerful sensitizer of death receptor-induced apoptosis in cancer cells.     

miR-125a-5p通过靶向APAF1 增强非小细胞肺癌细胞吉非替尼耐药性

目的：探讨miR-125a-5p 在诱导非小细胞肺癌（non-small cell lung cancer，NSCLC）细胞吉非替尼（gefitinib，Gef）耐药中的作用及其机制。方法：选用人NSCLC 耐药细胞株A549/GR 和NSCLC细胞株A549，将miR-125a-5p mimic、miR-125a-5p inhibitor、pcDNA3.1-APAF1、空载体pcDNA3.1 转染至A549/GR细胞。用qPCR检测细胞中miR-125a-5p 的表达水平，用MTT法、Transwell 小室法和流式细胞术检测Gef 对细胞增殖、迁移和凋亡的影响。用双荧光素酶报告基因实验验证miR-125a-5p 与细胞凋亡蛋白酶活化因子1（apoptotic peptidase activating factor 1，APAF1）的靶向关系，用Western blotting检测A549/GR细胞中APAF1蛋白水平，用比色法测定细胞中caspase-3 及caspase-9 表达水平。结果：A549/GR 细胞中miR-125a-5p 表达水平显著高于A549 细胞（P<0.01）。敲降miR-125a-5p 显著增强Gef 对A549/GR细胞增殖、迁移的抑制作用（均P<0.05），并促进细胞凋亡（P<0.01）。双荧光素酶报告基因实验证实miR-125a-5p 靶向APAF1，并负调控其表达。进一步实验显示，miR-125a-5p 通过靶向下调APAF1 缓解Gef 对A549/G 细胞增殖、迁移的抑制作用及凋亡的促进作用（均P<0.05），减弱Gef引起的凋亡相关蛋白caspase-3及caspase-9表达的上调（均P<0.05）。结论：miR-125a-5p 促进NSCLC细胞Gef 耐药，其机制是通过靶向APAF1 而促进细胞的增殖、迁移并抑制凋亡。     

Gambogic acid synergistically potentiates cisplatin-induced apoptosis in non-small-cell lung cancer through suppressing NF-κB and MAPK/HO-1 signalling

Background:

Gambogic acid (GA) has been reported to have potent anticancer activity and is authorised to be tested in phase II clinical trials for treatment of non-small-cell lung cancer (NSCLC). The present study aims to investigate whether GA would be synergistic with cisplatin (CDDP) against the NSCLC.

Methods:

1-(4,5-Dimethylthiazol-2-yl)-3,5-diphenylformazan (MTT), combination index (CI) isobologram, western blot, quantitative PCR, flow cytometry, electrophoretic mobility shift assay, xenograft tumour models and terminal deoxynucleotide transferase-mediated dUTP nick-end labelling analysis were used in this study.

Results:

The cell viability results showed that sequential CDDP-GA treatment resulted in a strong synergistic action in A549, NCI-H460, and NCI-H1299 cell lines, whereas the reverse sequence and simultaneous treatments led to a slight synergistic or additive action. Increased sub-G1 phase cells and enhanced PARP cleavage demonstrated that the sequence of CDDP-GA treatment markedly increased apoptosis in comparison with other treatments. Furthermore, the sequential combination could enhance the activation of caspase-3, -8, and 9, increase the expression of Fas and Bax, and decrease the expression of Bcl-2, survivin and X-inhibitor of apoptosis protein (X-IAP) in A549 and NCI-H460 cell lines. In addition, increased apoptosis was correlated with enhanced reactive oxygen species generation. Importantly, it was found that, followed by CDDP treatment, GA could inhibit NF-κB and mitogen-activated protein kinase (MAPK)/heme oxygenase-1 (HO-1) signalling pathways, which have been validated to reduce ROS release and confer CDDP resistance. The roles of NF-κB and MAPK pathways were further confirmed by using specific inhibitors, which significantly increased ROS release and apoptosis induced by the sequential combination of CDDP and GA. Moreover, our results indicated that the combination of CDDP and GA exerted increased antitumour effects on A549 xenograft models through inhibiting NF-κB, HO-1, and subsequently inducing apoptosis.

Conclusion:

Gambogic acid sensitises lung cancer cells to CDDP in vitro and in vivo in NSCLC through inactivation of NF-κB and MAPK/HO-1 signalling pathways, providing a rationale for the combined use of CDDP and GA in lung cancer chemotherapy.     

Inhibitory effect of riccardin D on growth of human non-small cell lung cancer: in vitro and in vivo studies

Riccardin D is a macrocyclic bisbibenzyl compound extracted from liverwort plant Dumortiera hirsuta. Our previous study showed that riccardin D induced apoptosis of human leukemia cells by targeting DNA topoisomerase II (topo II). Riccardin D has been considered as a novel DNA topo II inhibitor and potential chemotherapeutic agent for treatment of cancers. In this study, we evaluated the inhibitory effects of riccardin D on growth of human non-small cell lung cancer (NSCLC) both in vitro and in vivo. Riccardin D effectively inhibited the proliferation of NSCLC cells as estimated by the MTT assay. Further examination showed that the ability of invasion and migration of NSCLC cells was suppressed on exposure to riccardin D as estimated by the assays of scratch and transwell chamber. The anticancer activity of riccardin D was verified in mice bearing human NSCLC H460 xenografts. Riccardin D injection produced a 44.5% inhibition of cancer growth without apparent signs of toxicity to animals. Further, riccardin D induced apoptosis of NSCLC cells as evidenced by the increases of cells with externalization of phosphatidylserine and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive in H460 xenografts. The analysis of apoptotic proteins showed that riccardin D activated the caspases cascade signaling pathway as demonstrated by the increases of cleaved caspase-3 and cleaved PARP in NSCLC cells in vitro and in H460 xenografts in mice. The pBR322 DNA relaxation assay indicated that riccardin D inhibited the activity of DNA topo II in H460 and A549 cells, suggesting the mechanism of riccardin D in induction of NSCLC apoptosis. In addition, we studied the activity and expression of matrix metalloproteinases (MMPs) in NSCLC cells. The activities of MMP-2 and MMP-9 in supernatants of NSCLC cells were suppressed on exposure to riccardin D as estimated by gelatin zymography assay. The inhibitory effects of riccardin D on expressions of MMP-2 and MMP-9 were verified in H460 xenografts in mice and the decreases of vascular endothelial growth factor (VEGF) and Erk1/2 might associate with the inhibition of MMPs and NSCLC growth. Together, our results suggest that riccardin D has a high inhibitory effect on human NSCLC growth through induction of apoptosis.     

隐丹参酮联合顺铂抗非小细胞肺癌NCI-H1975细胞JAK2/STAT3机制研究

目的 探讨隐丹参酮与顺铂联合作用于非小细胞肺癌NCI-H1975细胞具有协同抗肿瘤效应及其可能的分子机制。方法 实验分为对照组、隐丹参酮组、顺铂组及隐丹参酮和顺铂联合用药组(以下简称联合用药组),CCK-8法测定细胞增殖抑制率,流式细胞术测定细胞存活率及凋亡,免疫印迹技术检测用药后凋亡蛋白、抗凋亡分子蛋白表达水平、JAK2/STAT3蛋白及其磷酸化表达水平,激光共聚焦/荧光素酶检测STAT3细胞定位和转录活性。结果 (1)在各时间点,单药组及联合用药组存活率均低于对照组(P＜0.05);与对照组及单药组相比,联合用药组在各时间点均抑制NCI-H1975细胞增殖活性(P＜0.05);(2)联合用药组作用于NCI-H1975细胞24 h后,抗凋亡蛋白Bcl-2、Survivin表达水平下降(P＜0.01),Caspase3和Caspase9活性提高(P＜0.01),p-STAT3及p-JAK2表达水平下降(P＜0.01);(3)联合用药组作用于NCI-H1975细胞后,激光共聚焦检测提示细胞核内STAT3明显减少,核内STAT3活性降低。结论 隐丹参酮联合顺铂作用于非小细胞肺癌NCI-H1975细胞能发挥协同抗肿瘤作用,其机制与抑制信号通路JAK2/STAT3磷酸化表达水平有关。     

Histone deacetylase inhibitors suppress the inducibility of nuclear factor-kappaB by tumor necrosis factor-alpha receptor-1 down-regulation

Recently, the inhibition of histone deacetylase (HDAC) enzymes has attracted attention in the oncologic community as a new therapeutic opportunity for hematologic and solid tumors including non-small cell lung cancer (NSCLC). In hematologic malignancies, such as diffuse large B-cell lymphoma, the HDAC inhibitor (HDI), suberoylanilide hydroxamic acid (SAHA), has recently entered phase II and III clinical trials. To further advance our understanding of their action on tumor cells, we investigated the possible effect of HDI treatment on the functionality of the nuclear factor-kappaB (NF-kappaB) pathway in NSCLC. We found that in the NSCLC cell lines, A549 and NCI-H460, the NF-kappaB pathway was strongly inducible, for example, by stimulation with tumor necrosis factor-alpha (TNF-alpha). Incubation of several NSCLC cell lines with HDIs resulted in greatly reduced gene expression of TNF-alpha receptor-1. HDI-treated A549 and NCI-H460 cells down-regulated TNF-alpha receptor-1 mRNA and protein levels as well as surface exposure, and consequently responded to TNF-alpha treatment with reduced IKK phosphorylation and activation, delayed IkappaB-alpha phosphorylation, and attenuated NF-kappaB nuclear translocation and DNA binding. Accordingly, stimulation of NF-kappaB target gene expression by TNF-alpha was strongly decreased. In addition, we observed that SAHA displayed antitumor efficacy in vivo against A549 xenografts grown on nude mice. HDIs, therefore, might beneficially contribute to tumor treatment, possibly by reducing the responsiveness of tumor cells to the TNF-alpha-mediated activation of the NF-kappaB pathway. These findings also hint at a possible use of HDIs in inflammatory diseases, which are associated with the overproduction of TNF-alpha, such as rheumatoid arthritis or Crohn's disease.