Notch signaling inhibits growth of the human lung adenocarcinoma cell line A549

In lung cancers the Notch signaling may function as an oncogene or a tumor suppressor depending on the tumor cell types. In this study we examined the expression of Notch receptors in the human lung adenocarcinoma cell lines A549 and SPC-A-1. We over-expressed the active form of Notch1 (NIC) in A549 cells by constitutive transfection to evaluate the effects of the Notch signaling on lung adenocarcinoma cells. Our results showed that over-expression of NIC in A549 cells inhibited the growth of A549 cells through induction of cell cycle arrest. Moreover, over-expression of NIC inhibited the colony-forming activity of A549 cells when cultured in methylcellulose medium, and their ability to form tumors in nude mice. These data suggest that the Notch signaling may function as a tumor inhibitor in human lung adenocarcinoma cells.     

原花青素诱导人肺癌细胞A549凋亡作用研究

目的研究原花青素对人肺癌细胞株A549凋亡的影响并探讨其抗癌机制。方法以不同浓度的原花青素与人肺癌细胞株A549细胞共同培养,MTT法测定细胞增殖;Hoechst 33258/PI染色荧光显微镜下观察凋亡细胞形态学变化;DNA琼脂糖凝胶电泳检测凋亡特异性梯状DNA条带;Western blot检测细胞凋亡相关蛋白Caspase-9、Caspase-3和Bcl-2表达的变化。结果原花青素可体外抑制肺癌A549细胞生长,抑制率呈浓度、时间依赖性,药物浓度达25 mg/L时作用48小时,A549细胞皱缩、细胞核碎裂成碎片,呈现典型凋亡改变;琼脂糖凝胶电泳可见凋亡细胞典型的梯状DNA条带;Western blot检测结果显示,Caspase-9、Caspase-3蛋白表达量与药物浓度的增加呈增加趋势,Bcl-2与药物浓度呈负相关。结论原花青素能通过诱导细胞凋亡进而抑制人肺癌细胞增殖,其凋亡机制可能与线粒体通路有关。     

顺铂诱导A549细胞凋亡的研究

目的 探讨顺铂诱导肺癌细胞凋亡的规律，机制以及在肿瘤化疗中的作用。方法 应用形态学观察，琼脂糖凝胶电泳，原位DNA断裂点的末端标记法和流式细胞仪分析技术，检测顺铂诱导A549细胞的凋亡作用。结果 3mg/L顺铂诱导的细胞凋亡在12-72h持续存在并逐渐增强，呈时间依赖性；顺铂浓度分别为1、3、5、7mg/L时均诱导了细胞凋亡，呈浓度依赖性，在顺铂作用下，细胞被阻滞于G1期。结论 诱导细胞凋亡可能是顺铂抗肿瘤作用的重要机制。     

蝙蝠葛提取物对人肺癌细胞系A549诱导凋亡作用的研究

目的探讨蝙蝠葛提取物对人肺癌细胞系A549诱导凋亡和抗增殖作用及其机制,为开发抗肿瘤新中药提供实验依据。方法应用MTT法测定蝙蝠葛提取物对人肺癌细胞系A549的生长抑制作用;通过倒置显微镜、光学显微镜观察肿瘤细胞凋亡的形态学变化;采用流式细胞术检测A549细胞的凋亡率;应用免疫组织化学技术检测药物处理前后凋亡相关蛋白酶caspase-3、caspase-8、caspase-9的表达。结果 （1）MTT法检测结果：蝙蝠葛提取物对人肺癌细胞系A549有明显的抑制生长的作用,且呈现出浓度的依赖性;（2）倒置显微镜观察结果：实验组肿瘤细胞体积变小、变圆,核染色质凝集,细胞间连接疏松,贴壁能力减弱;（3）HE染色观察结果：实验组肿瘤细胞体积变小、变圆,核染色质浓缩或染色质块形成,有的细胞膜起泡形成凋亡小体;（4）流式细胞术检测结果显示：蝙蝠葛提取物可以诱导A549细胞发生凋亡,加药组出现亚二倍体峰。结论 （1）蝙蝠葛提取物在体外对人肺癌细胞系A549有显著的诱导凋亡作用;（2）蝙蝠葛提取物诱导凋亡作用机制可能通过上调caspase-3、caspase-8和caspase-9蛋白表达,经由细胞凋亡的死亡受体和线粒体通路完成凋亡的启动和执行;（3）蝙蝠葛提取物具有显著的体外抗肿瘤作用,有望开发成一种新的抗肿瘤药物。     

Inactivation of ErbB3 by siRNA promotes apoptosis and attenuates growth and invasiveness of human lung adenocarcinoma cell line A549

The ErbB3 receptor and the downstream signaling kinase Akt are implicated in proliferation of lung adenocarcinoma cells. Inhibition by siRNAs to ErbB3 and Akt isoforms 1, 2 and 3 was utilized to investigate the contribution of these molecules to tumor survival, spreading and invasiveness, and the roles of specific Akt isoforms. ErbB3 siRNA stably and dose-dependently suppressed ErbB3 protein for 2 days or more, and reduced cell numbers, by both suppressing cell cycle and causing apoptosis and necrosis. It also inhibited soft agar growth, cell motility and migration, and invasiveness. Akt1, 2 and 3 siRNAs had similar suppressive effects on cell number, apoptosis/necrosis and soft agar growth. However, although Akt1 siRNA had no effect on cell migration or invasion, Akt2 siRNA effectively suppressed both activities, and Akt3 siRNA had moderate effectiveness. In A549 cells, ErbB3 is indicated as having major effects on cell division, survival, motility, migration and invasiveness. All three Akt isoforms are to varying degrees involved in these cell behaviors, with Akt2 especially implicated in migration and invasion. ErbB3 and the Akts are promising targets for therapy, and siRNAs may be useful for this purpose.     

紫花牡荆素诱导人肺癌Ａ５４９细胞凋亡及其机制的探讨

目的　探讨紫花牡荆素（ＣＡＳ）诱导人肺癌Ａ５４９细胞凋亡及其机制。方法　体外培养Ａ５４９细胞。ＭＴＴ法测定ＣＡＳ对Ａ５４９细胞的增殖抑制作用;ＡｎｎｅｘｉｎＶ／ＰＩ双染色分析细胞凋亡率;ＪＣ-１探针流式细胞术分析线粒体跨膜电位;Ｗｅｓｔｅｒｎｂｌｏｔｔｉｎｇ法分析线粒体细胞色素Ｃ的释放和Ｂａｘ蛋白的表达。结果　ＣＡＳ能抑制人肺癌Ａ５４９细胞增殖,呈浓度依赖性。ＡｎｎｅｘｉｎＶ／ＰＩ法检测结果显示１０μｍｏｌ／ＬＣＡＳ作用Ａ５４９细胞１２、２４和４８ｈ后,凋亡率分别为２２.３９％、３８.６６％和６４.８２％。ＪＣ-１探针流式细胞术分析表明,ＣＡＳ能降低Ａ５４９细胞线粒体跨膜电位;Ｗｅｓｔｅｒｎｂｌｏｔｔｉｎｇ显示ＣＡＳ能促进线粒体细胞色素Ｃ的释放和上调Ｂａｘ蛋白表达。结论　ＣＡＳ具有诱导Ａ５４９细胞凋亡的作用,其作用机制可能与降低细胞线粒体膜电位、增加细胞色素Ｃ释放和上调Ｂａｘ蛋白表达有关。     

人肺腺癌A549/DDP耐药细胞减弱顺铂诱导的细胞凋亡

目的：探讨人肺腺癌Ａ５４９／ＤＤＰ耐药细胞的多药抗药机理。方法;应用形态学观察、琼脂糖凝胶电泳、原位ＤＮＡ断裂点的末端标记法观察细胞亡的状况,用免疫组化法检测ｂｃｌ－２基因的表达。结果：癌细胞在顺铂作用下产生了典型的凋亡形态学改革。３μｇ／ｍｌ,５μｇ／ｍｌ,７μｇ／ｍｌ顺铂作用４８小时,Ａ５４９细胞ＤＮＡ裂解片断呈现典型的阶梯状排列条喧,而在５μｇ／ｍｌ、７μｇ／ｍｌ顺铂作用４８小时,Ａ５４９／     

上调miRNA-145对肺癌细胞系A549增殖和凋亡的影响

目的探讨miRNA-145对肺癌细胞系A549增殖和凋亡能力的影响。方法采用实对荧光定量聚分酶链反应检测A549细胞中miRNA-145的表达,并将miRNA-145表达量上调(实验组)与空白对照组和阴性对照组比较,采用CCK8法检测并对比A549细胞增殖的改变。采用流式细胞仪检测并对比A549细胞周期以及凋亡的改变。结果 RT-PCR结果表明,侵染了miRNA-145过表达载体的A549细胞中miRNA-145水平明显高于阴性对照组及空白对照组,差异有统计学意义(P<0.01);上调A549细胞中miRNA-145的表达量,可使A549细胞出现S期阻滞,凋亡增加、增殖减缓(P<0.05)。结论过表达miRNA-145能够抑制A549细胞的增殖并诱导A549细胞的凋亡,有可能为肺癌分子靶向治疗调控效应靶点作进一步探索研究。     

Acacetin-induced cell cycle arrest and apoptosis in human non-small cell lung cancer A549 cells

In this study, we examined acacetin (5,7-dihydroxy-4'-methoxyflavone), a flavonoid compound, for its effect on proliferation in human non-small cell lung cancer A549 cells. The results first reported that acacetin not only inhibited A549 cell proliferation but also induced apoptosis and blocked cell cycle progression in the G1 phase. ELISA assay demonstrated that acacetin significantly increased the expression of p53 and p21/WAF1 protein, which caused cell cycle arrest. An enhancement in Fas and its two forms of ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), might be responsible for the apoptotic effect induced by acacetin. Taken together, p53 and Fas/FasL apoptotic system may participate in the antiproliferative activity of acacetin in A549 cells.     

TOB1高表达抑制肺癌A549细胞体外迁移和侵袭

目的:探讨TOB1 (transducer of ErbB 2,1)高表达对人肺癌A549细胞体外迁移和侵袭的影响.方法:应用RT-PCR法检测人支气管上皮细胞HBE和10种肺癌细胞中TOB1、PTEN (phosphatase and tensin homolog deleted on chromosome ten)、乳腺癌转移抑制基因1(breast cancer metastasis suppressor 1,BRMS1)、RHOC(ras homolog gene family,member C)和NME1 (non-metastatic cells 1)mRNA的表达水平;将重组表达载体质粒pcDNA3.0-TOB1和“空载体”质粒pcDNA3.0转染到A549细胞中,建立TOB1高表达的A549/TOB1细胞和对照组A549/PC3细胞,应用体外划痕和Transwell实验检测细胞的体外迁移和侵袭能力,RT-PCR法检测细胞中PTEN、BRMS1、RHOC和NME1 mRNA的表达,蛋白质印迹法检测细胞中α-N-catenin、β-catenin、γ-catenin、基质金属蛋白酶2(matrix metalloproteinase 2,MMP2)和MMP9蛋白的表达.结果:10种肺癌细胞中TOB1 mRNA的表达水平明显低于HBE细胞(P＜0.05),不同细胞株中TOB1 mRNA与PTEN、BRMS1和NME1 mRNA的表达水平间呈正相关(P＜0.05).A549/TOB1细胞的体外迁移和侵袭能力明显低于A549细胞(P＜0.05).A549/TOB1细胞中PTEN、BRMS1和NME1 mRNA的表达水平明显高于A549细胞(P＜0.05),而RHOC mRNA的表达水平明显低于A549细胞(P＜0.05); A549/TOB1细胞中α-N-catenin、β-catenin、γ-catenin、MMP2和MMP9蛋白的表达水平明显低于A549细胞(P＜0.05).结论:外源性TOB1高表达可以明显抑制肺癌A549细胞的体外转移和侵袭,其机制可能与TOB1调控PTEN、BRMS1、RHOC和NME1的表达,进一步下调α-N-catenin、β-catenin、γ-catenin、MMP2和MMP9蛋白的表达水平有关.     

益生饮药物血清对A549人肺癌细胞株体外生长的影响

目的观察益生饮药物血清对A549人肺癌细胞株体外生长的影响。方法以不同浓度的益生饮药物血清培养人肺癌细胞A549,用MTT技术体外观察不同浓度益生饮药物血清对人肺癌细胞生长的影响。结果各组抑瘤率分别为：大剂量组41．18％,中剂量组33．16％,小剂量组25．67％,3种剂量组间差异显著（P〈0．01）。抑瘤率以大剂量组最高,为41．18％。结论益生饮药物血清对肺癌A549细胞体外生长有较好的抑制作用。     

腺病毒介导的FasL基因转移及对肺癌细胞生长和凋亡的影响

目的：探讨FasL基因对人肺癌的作用以及FasL基因治疗肺癌的可能性。方法：通过腺病毒载体介导FasL基因转移到低水平表达FasL的人肺腺癌细胞系A549,对FasL基因的表达、细胞生长的抑制和肿瘤生长模型的治疗效果进行分析。结果：外源性FasL基因在靶细胞高水平的表达显著抑制了A549的生长和集落形成，流式细胞仪检测显示细胞G1期阻滞并发生了凋亡。瘤内注射Ad-FasL对裸鼠体内移植瘤有一定的抑瘤作用。结论：FasL基因参与了肿瘤细胞凋亡的诱导，能抑制肺腺癌细胞的生长，因此本基础在肿瘤的基础治疗上有着广泛的应用前景。     

托瑞米芬协同顺铂对人肺癌细胞株A549的影响

目的：研究托瑞米芬（TOR）对人肺腺癌细胞系A549的毒性作用及其与顺铂（DDP）联用的协同效应,探讨肺癌综合治疗的方向。方法：用MTT显色法检测TOR及与DDP联用后对A549细胞的毒性作用,测定其吸光度（A）值。用流式细胞仪检测细胞DNA含量,Western blot法检测p21蛋白表达。结果：TOR能直接抑制A549细胞的生长,≥5μmol/L的TOR可明显增强DDP的细胞毒性作用。TOR可加强DDP对S期、G2期及M期细胞的作用,且DDP＋TOR后p21蛋白表达增加。结论：≥5μmol/L的TOR与DDP联用对A549细胞具有显著的协同抗肿瘤效应。     

Re-expression of TSLC1 in a non-small-cell lung cancer cell line induces apoptosis and inhibits tumor growth

The TSLC1 tumor-suppressor gene is silenced in a number of human cancer tissues and cell lines, including lung, prostate, liver, stomach, pancreatic, and breast cancers. Expression of TSLC1 in a non-small-cell lung cancer (NSCLC) cell line A549 suppresses tumorigenicity in nude mice. However, the molecular mechanism of TSLC1 action is not yet elucidated. In the present study, we show that the expression of TSLC1 from a recombinant adenovirus vector (Ad-TSLC1) inhibited cell proliferation and induced apoptosis in the NSCLC cell line A549. We also demonstrated that subcutaneous tumor growth in nude mice induced by A549 cells was suppressed to the extent of 70-80% by intratumoral injection of Ad-TSLC1. Re-expression of TSLC1 also resulted in activation of the apoptotic protease caspase-3, accompanied by the cleavage of its substrate poly (ADP-ribose) polymerase (PARP). The antiproliferative and pro-apoptotic activity of TSLC1 required the presence of the FERM-binding and PDZ-interacting motifs located in the cytoplasmic domain. Our results demonstrate the pro-apoptotic and oncosuppressive activity of TSLC1 protein, and suggest the potential of TSLC1 for gene therapy.     

Pachymic acid inhibits cell growth and modulates arachidonic acid metabolism in nonsmall cell lung cancer A549 cells

Aberrant arachidonic acid (AA) metabolism has been involved in inflammation and carcinogenesis. The key enzymes in AA metabolism such as cytosolic phospholipase A2 (cPLA₂) and cyclooxygenase‐2 (COX‐2) have been implicated in the development and progression of many human cancers, including lung cancer. Hence, the blockade of these enzymes may suppress promotion and survival of human cancer cells. We and others have shown that a natural triterpenoid, pachymic acid (PA), can exhibit antiinflammatory and anticancer properties; however, its potential mechanism has not been fully clarified. In this study, we examined the effect of PA on the proliferation of human nonsmall cell lung cancer A549 cells. Furthermore, we investigated the influences of nontoxic levels of PA on AA metabolism. Additionally, the cellular events and signal transduction pathways influenced by PA were also examined. Our results showed that PA (1) inhibited anchorage‐dependent and ‐independent A549 growth in a concentration‐dependent manner, (2) induced apoptosis and disrupted mitochondrial membrane potential in A549 cells, and at nonlethal levels, (3) decreased IL‐1β‐induced activation of cPLA₂ and COX‐2, (4) suppressed IL‐1β‐induced activation of mitogen‐activated protein kinases (MAPKs), and (5) inhibited IL‐1β‐stimulated nuclear factor kappa B (NF‐κB) signaling pathways. We speculate that inhibition of AA metabolism by PA is mediated in part by its inhibition of MAPKs and NF‐κB signaling pathways. Our study reveals that, apart from its cytotoxic effect, PA has the chemopreventive potential by reducing production of eicosanoids from AA metabolism. © 2009 Wiley‐Liss, Inc.     

乏氧对多柔比星诱导肺腺癌A549细胞凋亡的影响

背景与目的：乏氧是恶性肿瘤中常见的现象。乏氧时肿瘤细胞对化疗抗拒，细胞凋亡减少：本实验通过研究乏氧对肺腺癌A549细胞（野生型P53）多药耐药蛋白表达及细胞凋亡的影响，探讨乏氧在多柔比旱诱导细胞凋亡巾的作用。方法：乏氧条件下（2％O，）人肺腺癌细胞株A549体外培养24h，免疫组化法榆测乏氧诱导因子-1d（HIF-1α）、P-糖蛋白（P-gP）和P53蛋白的表达；MTT法检测乏氧条件下A549细胞在多柔比星作用下的存活率；应用流式细胞仪检测细胞凋亡i结果：①乏氧条件下A549中HIF-1α、P-gp和P53蛋白的表达明显较正常氧浓度下增高，HIF-1α蛋白的表达与P-gP和P53蛋白的表达存在明显的相关性、名乏氧条件下A549细胞对多柔比星的耐药性明显增强，多柔比旱诱导细胞凋亡率明显减低：结论：乏氰情况下，A549细胞能够通过HIF-1仅上调P-gp和P53蛋白的表达；A549细胞住乏氧条件下多柔比星诱导细胞凋亡存在非P53依赖途径？     

顺维甲酸体外诱导肺腺癌细胞A549凋亡的研究

目的:探讨9-顺维甲酸(9-cis-RA)对人肺腺癌细胞A549的诱导凋亡作用。方法:体外培养肺腺癌细胞株A549,用MTT法观察9-cis-RA对细胞的生长抑制作用,采用电镜、流式细胞仪等方法检测9-cis-RA对细胞的诱导凋亡作用。结果:9-cis-RA对A549细胞有生长抑制效应,抑制率随着9-cis-RA浓度、作用时间的增加而增加。9-cis-RA明显诱导A549细胞的凋亡,可观察到凋亡小体和凋亡峰,药物作用48h后,9-cis-RA浓度为5、10μmol/L的细胞凋亡率分别为7.2%和13.3%,细胞凋亡率呈现量效关系。结论:9-cis-RA可能通过诱导肺癌细胞凋亡抑制肺癌细胞增殖,发挥其抗癌作用。     

靶向SATB1基因的短发夹RNA诱导肺癌A549细胞凋亡

目的:探讨靶向SAT B1(special AT-rich sequence-binding protein-1)基因的短发夹RNA (short hairpinRNA,shRNA)对肺癌A549细胞凋亡的影响及其可能的机制.方法:构建靶向SATB1基因的shRNA重组质粒SATB1-shRNA,采用脂质体法将其转染至A549细胞;分别采用RT-PCR和蛋白质印迹法检测A549细胞中SATB1、Bcl-2、Bax mRNA和SATB1、Bcl-2、Bax、caspase 3蛋白的表达水平FCM检测A549细胞的凋亡率.结果:成功构建了SATB1-shRNA重组质粒;SATB1-shRNA转染A549细胞后,SATB1、Bcl-2 mRNA及其蛋白表达下调,Bax mRNA和Bax、caspase 3蛋白表达上调(p＜0.05).SATB1-shRNA转染组细胞凋亡率[(14.18±1.59)％]较对照组[(1.84±0.57)％]明显增加(P＜ 0.01).结论:SATB1-shRNA可显著下调肺癌A549细胞中SATB1基因的表达水平并诱导细胞凋亡,其机制可能与下调Bcl-2基因表达所引起的级联效应有关.     

HDAC1 siRNA转染对肺腺癌A549细胞增殖及凋亡的影响

背景与目的:多项研究表明组蛋白去乙酰化酶(histone deacetylases,HDACs)抑制剂对人非小细胞肺癌细胞株有抑制增殖和诱导凋亡作用.而HDAC抑制剂对HDAC Ⅰ型和Ⅱ型均有抑制作用,在非小细胞肺癌细胞株中尚未明确HDACs中哪一类受抑制能影响肿瘤生长.本研究通过HDAC1 siRNA转染肺腺癌细胞株A549,观察HDACs中HDAC1对肺腺癌细胞增殖、周期和凋亡的影响,明确HDAC1在肺腺癌细胞生长中的作用.方法:MTT法检测不同时间点HDAC1 si RNA转染对A549细胞体外增殖的影响,流式细胞术检测RNA干扰后细胞周期及凋亡率的变化;Western blot法检测细胞内组蛋白H4乙酰化水平的变化.结果:HDAC1 siRNA转染A549细胞后,HDAC1在转录和表达水平均下降,组蛋白H4乙酰化表达增高.siRNA干扰后A549细胞的体外生长抑制呈时间依赖性,流式细胞术检测结果显示细胞阻滞于G2/M期,细胞凋亡增加.结论:HDAC1 siRNA转染能有效地抑制HDAC1在A549细胞中的表达,增加A549细胞中组蛋白的乙酰化,并影响A549细胞相关生物学行为,抑制肺腺癌细胞的生长,为HDAC1基因治疗应用于肺腺癌奠定了基础.