蛋白激酶C抑制剂对人非小细胞肺癌细胞株药物敏感性的影响

背景与目的 蛋白激酶C(PKC)在癌变过程中的作用使其成为肿瘤治疗的潜在重要靶点.非小细胞肺癌(NSCLC)中存在PKC-α的异常表达和活性增高,PKC抑制剂能通过诱导肿瘤细胞凋亡、增强细胞毒作用及下调多药耐药基因的表达而发挥其抗肿瘤作用.通过观察PKC抑制剂白屈菜红碱(CH)对四种人NSCLC细胞株药物敏感性的影响,初步探讨其作用机制.方法 以PKC抑制剂CH分别处理四种NSCLC细胞株H1299、H460、A549及耐顺铂A549细胞株,逆转录聚合酶链式反应法(RT-PCR)及蛋白印迹法(Western blot)检测PKC-α的mRNA及蛋白表达水平,流式细胞仪检测细胞凋亡率,四甲基偶氮唑蓝(MTT)法检测细胞株对顺铂药物敏感性.结果 用药前A549/DDP细胞株中PKC-α mRNA及蛋白的表达水平高于NSCLC细胞株H1299、H460及亲本A549细胞株(P＜0.05),CH处理后四种NSCLC细胞株中PKC-αmRNA及蛋白的表达水平均有不同程度的下降,CH处理4 h及24 h后H1299、H460、A549细胞株的凋亡率无明显增加,仅A549/DDP细胞株的凋亡率明显增加,用药后NSCLC细胞株对顺铂的药物敏感性即IC50值有不同程度的下降,以A549/DDP细胞株降低更为明显(P＜0.05).结论 四种NSCLC细胞株中存在PKC-αmRNA及蛋白的高表达.通过抑制NSCLC细胞株中PKC-α mRNA及蛋白的表达,PKC抑制剂CH能增加其对顺铂的药物敏感性.与亲本A549细胞株相比,PKC抑制剂CH能通过抑制耐顺铂A549细胞株中PKC-α蛋白的表达及增加细胞凋亡率,而更有效地增加其对顺铂的药物敏感性.     

酪氨酸激酶Etk/BMX对鼻咽癌细胞放射敏感性的影响

目的：研究酪氨酸激酶Etk/BMX对鼻咽癌细胞放射敏感性的影响并探讨其可能机制。 方法：利用脂质体2000将野生型酪氨酸激酶Etk/BMX表达质粒pcDNA3.0-Etk导入Etk/BMX低表达水平的鼻咽癌细胞株Sune-1中,建立Etk/BMX稳定高表达细胞株Sune-wt,空质粒pcDNA3.0转染细胞作为对照（Sune-vector）。X射线（0、2、4、10、15Gy）照射后,MTT法测定细胞的生存分数（survival fraction,SF）;流式细胞术检测细胞的凋亡率、细胞周期、增殖指数以及凋亡相关蛋白p53和bcl-2的变化情况。结果：不同剂量X线照射后Sune-wt较Sune-1和Sune-vector生存分数（SF）均显著增高而凋亡均显著减少(P＜0.05),累计剂量15Gy后出现明显S、G2期阻滞,增殖指数增高。Sune-wt照射前后p53和bcl-2的表达水平出现显著改变(P＜0.05)。结论：Etk/BMX有增强鼻咽癌细胞对放射线的抵抗作用,其可能是通过调控p53和bcl-2的表达以及引起S、G2期阻滞两种途径实现的。     

重楼皂苷Ⅰ对肺腺癌A549细胞系放射增敏作用研究

[目的]探讨重楼皂苷Ⅰ对肺腺癌A549细胞的体外放射增敏作用及其可能机制.[方法]以肺腺癌A549细胞系为研究对象,MTT法检测重楼皂苷Ⅰ对A549细胞的抑制率,得到重楼皂苷Ⅰ对A549细胞的半数抑制浓度(IC50)及IC20、IC30,取IC20-30之间的重楼皂苷Ⅰ浓度用于放射增敏,随机分为对照组、单纯照射组、重楼皂苷Ⅰ、重楼皂苷Ⅰ+照射组,描绘细胞生长曲线、计算克隆形成率、流式细胞术检测细胞周期及凋亡率,Western Blot法检测survivin及p21waf/cip1蛋白表达.[结果]A549细胞在经重楼皂苷Ⅰ处理和照射后重楼皂苷Ⅰ+照射组A549细胞的增殖能力明显受抑(P＜0.01),克隆形成率明显下降(3.3％,P＜0.01),流式细胞术分析显示在重楼皂苷Ⅰ+照射组G2/M期阻滞(37.56％±1.99％,P＜0.01),凋亡率明显升高(9.34％±0.84％,P＜0.01).Western Blot检测survivin蛋白表达降低,而p21waf1/cip1蛋白表达增加.[结论]重楼皂苷Ⅰ具有较好的放射增敏作用,可能通过诱导细胞凋亡,细胞G2/M期阻滞,降低survivin蛋白表达,增加p21蛋白表达,从而产生放射增敏作用.     

蛋白激酶CK2抑制剂对肺癌细胞系放射敏感性的影响

目的 探讨蛋白激酶CK2抑制剂对肺癌细胞系放射敏感性的影响。方法 通过蛋白印迹法检测蛋白激酶CK2α、β亚基在不同肺癌细胞系中的表达情况。平板克隆形成试验检测CK2激酶抑制剂醌茜素对肺腺癌细胞A549和大细胞肺癌细胞H460对X线的放射敏感性影响。流式细胞术检测醌茜素与X线联合作用对A549、H460细胞凋亡及周期分布影响。组间比较采用方差分析和成组t检验。结果 蛋白激酶CK2α、β亚基在对放射不敏感的A549、H1650、H460细胞中高表达, 而在放射敏感的小细胞肺癌H446细胞中低表达。使用醌茜素预处理的A549、H460细胞存活分数(SF)明显低于未处理组, 25 μmol/L的增敏比(D₀值比)分别为2.771、2.463。醌茜素可引起细胞凋亡增加, 但X线联合醌茜素与单独醌茜素作用相比未增加A549细胞和H460细胞凋亡(X线照射+醌茜素:单独醌茜素, A549细胞P= 0.487和H460细胞P=0.254), 然而X线联合醌茜素与单独X线照射或醌茜素作用相比可明显引起其G₂+M期阻滞(X线照射+醌茜素:单独X线照射, A549细胞P=0.000, H460细胞P=0.0024;X线照射+醌茜素:单独X线照射, A549细胞P=0.000, H460细胞P=0.000)。结论 通过醌茜素抑制蛋白激酶CK2活性可增加NSCLC细胞的放射敏感性。     

DNA双链断裂修复蛋白表达水平与肿瘤细胞放射敏感性的关系研究

目的：检测肿瘤细胞株中DNA双链断裂修复蛋白（Ku80、DNA-PKcs和ATM）的表达水平和放射敏感性参数,探讨3个蛋白预示肿瘤细胞放射敏感性的价值。方法：培养4株人宫颈癌细胞HeLa、SiHa、C33A和Caski,3株人乳腺癌细胞MCF-7、MDA-MB-231和MDA-MB-453,及1株人肺癌细胞A549,Western blot检测这8株细胞中Ku80、DNA-PKcs和ATM蛋白的表达水平;流式细胞仪检测X线（10 Gy,6 MV）照射48 h后的凋亡率;克隆形成实验检测SF2（surviving fraction at 2 Gy）值和α、β值;Pearson线性相关分析蛋白表达水平与照射后凋亡率、SF2值和α/β比值的相关性。结果：3种蛋白在同一株细胞中的表达及同一蛋白在不同细胞株的表达均存在明显差异;DNA-PKcs的表达水平与SF2之间存在正相关关系（r=0.723,P=0.043）;Ku80和ATM的表达与SF2值间无明显相关关系（P〉0.05）。3种蛋白与凋亡率和α/β比值均无相关性（均P〉0.05）。结论：DNA-PKcs蛋白表达越高,细胞对放射线越抵抗,其表达水平可能成为指示肿瘤细胞放射敏感性的指标。     

甘露糖对6个人非小细胞肺癌细胞系放射敏感性影响

目的 探讨甘露糖对6个人非小细胞肺癌细胞系放射敏感性的影响及其可能机制。方法 采用Western blot检测磷酸甘露糖异构酶在6个肺癌细胞系中的表达。利用MTT法观察甘露糖对肺癌细胞系的增殖抑制作用;分别给予对照组、甘露糖组0、2、4、6、8、10Gy照射,采用平板克隆形成实验检测甘露糖对6个肺癌细胞放射敏感性的影响;流式细胞术检测对照组、甘露糖组、照射组及联合组细胞的凋亡情况。结果 6个肺癌细胞系中磷酸甘露糖异构酶表达量各不相同,其中A549细胞表达量最高,H460细胞表达量最低。11.1mmol/L甘露糖对A549、H460细胞系抑制作用相同,随着甘露糖浓度增加,对H460细胞系抑制作用更显著。采用11.1mmol/L的甘露糖可明显增加H460细胞系放射敏感性及细胞凋亡率,而对A549细胞系放射敏感性和凋亡率影响不大。结论 在磷酸甘露糖异构酶高表达的6个肺癌细胞系中,甘露糖可增强部分肿瘤细胞的放射敏感性。     

上调miRNA-145表达对非小细胞肺癌细胞增殖、凋亡及放射敏感性的影响

目的探讨上调miRNA-145表达对非小细胞肺癌细胞增殖、凋亡及放射敏感性的影响。方法收集人正常肺上皮细胞株BEAS-2B和非小细胞肺癌细胞株A549,采用逆转录聚合酶链反应(RT-PCR)检测两种细胞中miRNA-145的相对表达量。以Lipofectamine^TM 2000转染试剂将miRNA-145模拟物和阴性对照质粒转染至A549细胞中,分别作为miRNA-145组和NC组,以只加入转染试剂的A549细胞作为对照组,RT-PCR检测各组细胞中miRNA-145的相对表达量。采用四甲基偶氮唑蓝(MTT)法和流式细胞术(FCM)检测上调miRNA-145表达对细胞增殖和凋亡的影响。给予不同放射剂量X线照射后采用克隆形成实验检测细胞的放射敏感性。结果A549细胞中miRNA-145的相对表达量明显低于正常肺上皮BEAS-2B细胞(P<0.01);转染后,miRNA-145组细胞中miRNA-145的相对表达量高于对照组(P<0.05);转染后,NC组与对照组细胞中miRNA-145的相对表达量比较,差异无统计学意义(P﹥0.05);miRNA-145组细胞转染24、48、72 h的光密度(OD)值均低于对照组(P<0.05);转染48 h后,miRNA-145组细胞的凋亡率高于对照组(P<0.05);2、4、6、8 Gy剂量的X线照射后miRNA-145组细胞的存活分数(SF)均低于对照组,放射增敏比(SER)为1.491。结论与正常肺上皮BEAS-2B细胞比较,A549细胞中miRNA-145的相对表达量较低,上调其表达能够抑制A549细胞增殖,促进细胞凋亡,增强放射敏感性。     

放射诱导胃癌细胞的凋亡及其相关基因的研究

目的观察放射诱导人胃癌细胞株SGC-7901凋亡的作用，并进一步研究bcl-2基因及家族、bax基因、p53基因在此过程中的作用。方法用不同剂量的9 MeV β线照射SGC-7901细胞，观察细胞在受照后的不同时间生长情况。电子透射电镜下观察细胞形态变化。琼脂糖凝胶电泳检测DNA条带变化。流式细胞仪检测受照前后细胞周期及凋亡率的变化。免疫细胞化学法检测受照前后bcl-2、bax、p53基因的表达水平。结果单次剂量照射后，SGC-7901细胞凋亡率与时间、剂量有相关性。在放射诱导SGC-7901细胞凋亡的过程中，bcl-2基因表达水平下降，bax基因表达水平升高，而p53基因表达水平无变化。结论放射能够诱导胃癌细胞株SGC-7901凋亡，凋亡率在72h达高峰。bcl-2及bax基因参与了放射诱导凋亡的调控。细胞凋亡主要是通过p53基因非依赖途径。     

miR-30a-5p通过靶向下调ATF1提高非小细胞肺癌A549细胞放射敏感性北大核心

目的:探索miR-30a-5p对非小细胞肺癌(non-small cell lung cancer,NSCLC)A549细胞的放射增敏效应及其相关机制,为提高NSCLC放射敏感性提供理论依据。方法:采用qRT-PCR检测人正常肺上皮细胞株BEAS-2B、人肺癌细胞株A549、H460中miR-30a-5p表达情况;应用miR-30a-5p agomir、antagomir及对照转染A549细胞株,联合放射,检测miR-30a-5p对A549细胞株的放射增敏效应;通过生物信息学预测并筛选miR-30a-5p的靶基因,采用双荧光素酶报告基因检测进行验证;siATF1、miR-30a-5p agomir及siATF1+miR-30a-5p agomir转染A549细胞,通过qRT-PCR、Western Blotting检测靶基因表达与miR-30a-5p的关系,并通过平板克隆形成实验检测其对A549细胞株的放射增敏效应。结果:miR-30a-5p在A549和H460细胞株中表达均低于BEAS-2B细胞株(P<0.001);miR-30a-5p agomir转染联合放射,A549细胞放射生物学参数D_(0)、D_(q)、N较agomir NC组降低(均为P<0.05)。靶基因预测及验证结果显示,miR-30a-5p可以与ATF1的3'UTR特异性结合,ATF1是miR-30a-5p的一个靶基因,过表达miR-30a-5p可下调ATF1表达。siATF1、miR-30a-5p agomir及siATF1+miR-30a-5p agomir转染A549细胞联合照射,A549细胞克隆形成率及放射生物学参数D_(0)、D_(q)、N均低于对照组(均为P<0.05)。结论:miR-30a-5p通过靶向下调ATF1表达,在A549细胞中发挥放射增敏效应。     

LyGDI对肺癌A549细胞放射敏感性影响的观察

目的:研究X射线对稳定转染鸟苷解离抑制因子(LyGDI)A549细胞株放射敏感性的影响及相关机制。方法:应用生长曲线观察细胞增殖能力,流式细胞术检测不同剂量照射后转染组和对照组细胞的周期分布及凋亡率,克隆形成试验观察转染组细胞放射敏感性。结果:转染组细胞相对于对照组增殖能力减弱,F=212.55,P<0.01;克隆形成能力减弱,放射敏感性增加,F=7.56,P<0.05;流式细胞术检测到辐射诱导凋亡增加,F=18.45,P<0.01;细胞周期检测提示转染组G2期阻滞受抑制,F=6.29,P<0.05。结论:过度表达的LyGDI上调A549细胞放射敏感性,其可能机制为抑制G2期阻滞促进凋亡。     

Piperine induces apoptosis of lung cancer A549 cells via p53-dependent mitochondrial signaling pathway

The aim of this study was to evaluate the cytotoxic and apoptotic effects of piperine on human lung cancer A549 cells and to explore its mechanisms. Piperine was found to exert the greatest cytotoxic effect against A549 cells in a dose-dependent manner, whereas it showed no effect on WI38 human lung fibroblasts. This cell growth-inhibitory effect might be attributed to cell DNA damage and cytotoxic effects. Besides, piperine had the ability to cause cell cycle arrest in G2/M phase and to activate caspase-3 and caspase-9 cascades in A549 cells. Furthermore, piperine-induced apoptosis could be blocked by the broad caspase inhibitor z-VAD-fmk in majority. In addition, piperine treatment decreased Bcl-2 protein expression, but increased Bax protein expression in A549 cells, which were positively correlated with an elevated expression of p53 compared to control. Taken together, these results suggested that piperine could induce p53-mediated cell cycle arrest and apoptosis via activation of caspase-3 and caspase-9 cascades, as well as increasing the Bax/Bcl-2 ratio. Thus, piperine could be developed as an effective antitumor agent in the prevention and treatment of lung cancer without toxicity to the host.     

防己诺林碱对肺癌H1299和A549细胞的作用及其分子机制研究

目的 探究防己诺林碱在肺癌中的作用及其分子机制。方法 MTS法检测经10、15、20、30、40和60 μM/L防己诺林碱处理的肺癌H1299和A549细胞的增殖情况,通过Caspase3、Caspase8和Caspase9活性检测试剂盒和TUNEL试剂盒检测细胞凋亡情况。Western blot检测MAPK信号通路(p-Akt、PI3K、mTOR和Akt蛋白)、增殖和转移(MMP-2、MMP-9、PCNA、Cyclin D1和P21蛋白)、周期和凋亡(Cyclin D2、Bcl2、MCL-1、Bax和p53蛋白)相关蛋白的表达情况,通过Real-time PCR检测PI3k、mTOR、MMP-2、MMP-9、PCNA、Cyclin D1、Cyclin D2、MCL-1、Bax、Bcl2和TP53基因表达情况。结果 防己诺林碱会抑制肺癌H1299和A549细胞的增殖,诱导细胞凋亡,增加Caspase3、Caspase8和Caspase9酶活性。经防己诺林碱处理后,PI3K、p-Akt、mTOR、MMP-2、MMP-9、PCNA、Cyclin D1、Cyclin D2和Bcl2蛋白表达降低,P21、MCL-1、Bax和p53蛋白表达升高,并且表现为剂量依赖性,但对Akt蛋白表达无影响;PI3K、mTOR、MMP-2、MMP-9、PCNA、Cyclin D1、Cyclin D2和Bcl2基因表达降低,TP53、MCL-1和Bax基因表达增加。结论 防己诺林碱通过调控MAPK信号通路、增殖和转移、周期和凋亡相关蛋白和基因的表达,从而抑制细胞增殖,诱导细胞凋亡。     

p53 Cooperates berberine-induced growth inhibition and apoptosis of non-small cell human lung cancer cells in vitro and tumor xenograft growth in vivo

Berberine has been shown to have anti-carcinogenic effects. Since p53 is the most commonly mutated tumor suppressor gene, and a lack of functional p53 is associated with an increased risk of cancer development, we examined the effects of berberine on p53-positive and p53-deficient non-small cell human lung cancer cells in vitro and in vivo. Treatment of A549, which express wild-type p53, and H1299, which are p53-deficient, human lung cancer cells with berberine resulted in inhibition of cell proliferation and an increase in apoptotic cell death; however, A549 cells were more sensitive to the berberine-induced cytotoxic effects than H1299 cells. Further, the treatment of A549 cells with pifithrin-alpha, a specific inhibitor of p53, or transfection of A549 cells with a p53 antisense oligodeoxynucleotide resulted in a reduction in the berberine-induced inhibition of cell proliferation and apoptosis. The berberine-induced apoptosis of both the A549 and H1299 human lung cancer cells was associated with the disruption of mitochondrial membrane potential, reduction in the levels of Bcl-2, Bcl-xl while increase in Bax, Bak, and activation of caspase-3. Treatment of the cells with pan-caspase inhibitor (z-VAD-fmk) or caspase-3 inhibitor (z-DEVD-fmk) inhibited berberine-induced apoptosis, thus suggesting the role of caspase-3. Further, the administration of berberine by oral gavage inhibited the growth of s.c. A549 and H1299 lung tumor xenografts in athymic nude mice, however, the growth of tumor xenograft of H1299 cells was faster than A549 cells in mice and the chemotherapeutic effect of berberine was more pronounced in the p53-positive-A549 tumor xenograft than p53-deficient-H1299 tumor xenograft.     

Apoptotic effect of citrus fruit extract nobiletin on lung cancer cell line A549 in vitro and in vivo

Lung cancer is the leading cause for cancer-related death worldwide and the effectiveness of current treatments is very limited. Here we reported that Nobiletin, an effective component of citrus fruit, has antiproliferative activity on lung cancer cells both in vitro and in vivo. Cell viability and clonogenic assay showed that Nobiletin dose-dependently suppressed the proliferation of human lung adenocarcinoma cell line A549 cells, while has having a minimal effect on human umbilical vein endothelial cell line ECV-304 cells. DNA fragment assay and comet assay demonstrated that Nobiletin induced A549 cell apoptosis. Nobiletin-induced cell cycle arrest at G(2)/M phase was detected by Flow cytometric analysis. In addition, Western blot analysis revealed that A549 cells pretreated with Nobiletin showed decreased Bcl-2 and increased Bax protein expression, which were positively correlated with elevated expression of p53 compared to control. Furthermore, Nobiletin had overt inhibitory effect on the tumor growth in nude mice model was observed in vivo. Taken together, these results suggest that Nobiletin could induce p53-mediated cell cycle arrest and apoptosis via modulated the Bax:Bcl-2 protein ratio, is effective as a potent antitumor agent on lung tumors.     

PEBP4 enhanced HCC827 cell proliferation and invasion ability and inhibited apoptosis

The purposes of this study were to investigate the effects of phosphatidylethanolamine-binding protein 4 (PEBP4) on the cell growth, proliferation, apoptosis, and invasion of non-small cell lung cancer (NSCLC) cells and to provide evidence for future treatment options for NSCLC. Western blot assays were performed to examine PEBP4 protein expression levels in NSCLC cell lines (HCC827, A549, NCI-H661, NCI-H292, and 95-D) and a normal human bronchial epithelial (HBE) cell line. A PEBP4 shRNA expression vector was constructed and transfected into HCC827 cells. Subsequently, the effects of PEBP4 on the cell viability, cell cycle distribution, apoptosis levels, and invasion properties of HCC827 cells were analyzed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, flow cytometry analyses, and transwell invasion assays. In addition, the effects of PEBP4 on the expression of proteins including cyclin D1, p53, Bcl-2, MMP-2, and MMP-9 were investigated. PEBP4 was highly expressed in lung cancer cells (HCC827, A549, NCI-H661, NCI-H292, and 95-D), but its expression was low in HBE cells. Cell viability, cell proliferation, and invasion of HCC827 cells in the PEBP4 knockdown group were significantly lower than that in the negative control and blank control groups (p?<?0.05), and there were no significant differences between the negative and blank control groups in terms of cell viability, cell proliferation, apoptosis, and invasion. In HCC827 cells, the expression levels of cyclin D1, Bcl-2, MMP-2, and MMP-9 in the PEBP4 knockdown group were significantly lower (p?<?0.05), and the expression of p53 protein was significantly higher than that in the negative and blank control groups (p?<?0.05). There were no significant differences between the negative and blank control groups in the expression levels of cyclin D1, p53, Bcl-2, MMP-2, and MMP-9. In conclusion, PEBP4 enhanced HCC827 cell proliferation and invasion ability and inhibited apoptosis. Decreased PEBP4 expression may play a role in the reduced invasion ability and increased apoptosis of the human NSCLC cell line HCC827.     

Exogenous p53 Upregulated Modulator of Apoptosis (PUMA) Decreases Growth of Lung Cancer A549 Cells

Purpose: To investigate the influence of exogenous p53 upregulated modulator of apoptosis (PUMA) expressionon cell proliferation and apoptosis in human non-small cell lung cancer A549 cells and transplanted tumor cellgrowth in nude mice. Materials and Methods: A549 cells were divided into the following groups: control, noncarrier(NC), PUMA (transfected with pCEP4- (HA) 2-PUMA plasmid), DDP (10μg/mL cisplatin treatment)and PUMA+DDP (transfected with pCEP4-(HA)2-PUMA plasmid and 10μg/mL cisplatin treatment). The MTTmethod was used to detect the cell survival rate. Cell apoptosis rates were measured by flow cytometry, andPUMA, Bax and Bcl-2 protein expression levels were measured by Western blotting. Results: Compared to thecontrol group, the PUMA, DDP and PUMA+DDP groups all had significantly decreased A549 cell proliferation(p<0.01), with the largest reduction in the PUMA+DDP group. Conversely, the apoptosis rates of the three groupswere significantly increased (P < 0.01), and the PUMA and DDP treatments were synergistic. Moreover, Baxprotein levels significantly increased (p<0.01), while Bcl-2 protein levels significantly decreased (p<0.01). Finally,both the volume and the weights of transplanted tumors were significantly reduced (p<0.01), and the inhibitionratio of the PUMA+DDP group was significantly higher than in the single DDP or PUMA groups. Conclusions:Exogenous PUMA effectively inhibited lung cancer A549 cell proliferation and transplanted tumor growth byincreasing Bax protein levels and reducing Bcl-2 protein levels.     

短发夹RNA靶向沉默TPX2基因促进人肺腺癌A549细胞凋亡及其相关机制

目的:探讨靶向Xklp2靶蛋白(targeting protein for Xenopus kinesin-like protein2,TPX2)基因的短发夹RNA(short hairpin RNA,shRNA)对肺腺癌A549细胞凋亡的影响及其可能机制。方法:构建靶向TPX2基因的shRNA重组载体,将其转染至肺腺癌A549细胞中,RT-PCR检测细胞中TPX2、Aurora-A、p53和Bcl-2mRNA的表达,蛋白质印迹法检测TPX2蛋白的表达,FCM检测细胞周期和细胞凋亡情况。结果:成功构建重组载体pMagic4.1-shRNA-TPX2。将pMagic4.1-shRNA-TPX2转染至A549细胞后,TPX2、Aurora-A和Bcl-2mRNA的表达水平明显下调,p53mRNA的表达水平明显上调,TPX2蛋白的表达水平明显下调,细胞凋亡率明显增加,细胞阻滞于S期,与空白对照组(未转染组)和阴性对照组(转染pMagic4.1-shRNA-NC)相比,差异均有统计学意义(P<0.05)。结论:靶向TPX2的shRNA能促进肺腺癌A549细胞的凋亡,其作用可能与上调p53表达和下调Bcl-2表达有关。     

miRNA-192对非小细胞肺癌A549／DDP细胞顺铂耐药性的影响

目的 探讨抑制microRNA-192（miR-192）在非小细胞肺癌A549／DDP细胞对顺铂（DDP）耐药性方面的影响及可能机制。方法 通过实时荧光定量PCR（qRT-PCR）法检测人肺腺癌耐DDP细胞株A549／DDP及其亲本细胞株A549细胞中miR-192的表达水平,A549／DDP细胞转染miR-192抑制剂（inhibitor）和miR-阴性对照（NC）48h后采用qRT-PCR检测转染效率,分别采用MTT法、克隆形成实验及流式细胞术检测转染48h后A549／DDP细胞对DDP的药物敏感性、细胞增殖能力及细胞凋亡变化,Western blotting检测转染48h后细胞中Bax和Bcl-2的表达变化。结果 miR-192在A549／DDP细胞中的表达水平高于A549细胞（P＜0.05）;转染miR-192 inhibitor 48h后的A549／DDP细胞miR-192水平低于转染miR-NC者（P＜0.05）;转染miR-192 inhibitor后,A549／DDP细胞的增殖能力减弱、凋亡细胞增多、DDP对其半数抑制浓度降低、Bax蛋白水平升高和Bcl-2蛋白水平下降,与转染miR-NC者比较,差异均有统计学意义（P＜0.05）。结论 抑制miR-192能够降低A549／DDP细胞对DDP的耐药性,其作用机制可能是通过增加细胞凋亡以及下调Bcl-2蛋白和上调Bax蛋白表达来实现的。     

p53基因诱导胱癌细胞HTB9凋亡及相关基因的表达

目的 研究野生型p53基因诱导膀胱癌细胞凋亡的作用,及其对凋亡相关基因bcl-2、bax和ICE表达的调控。方法 将野生型p53基因重组腺病毒载体转染人膀胱癌细胞HTB9,应用RT－PCR检测bax的mRNA表达水平,应用免疫组化法检测bcl-2、bax和ICE蛋白表达水平,以DNA琼脂糖凝胶电泳、脱氧核苷酸转移酶介导的dUTP切口末端标记技术（TUNEL）和流式细胞仪检测细胞凋亡。结果 野生型p53基因导入可诱导HTB9细胞凋亡,凋亡细胞百分率可达50．4％;bax mRNA和蛋白水平增高,ICE和Bcl-2蛋白水平分别增高和下降。结论 野生型p53基因很可能是通过调控凋亡相关基因ICE、Bax和Bcl-2的表达来诱导细胞凋亡。     

榄香烯乳对人肺腺癌 A549 细胞株凋亡蛋白表达的影响

目的:探讨榄香烯乳对人肺腺癌A549细胞株凋亡蛋白表达的影响.方法:体外培养人肺腺癌A549细胞株,四甲基偶氮唑蓝比色试验法(MTT法)测定不同浓度榄香烯乳在不同作用时间下对A549细胞株的生长抑制作用.IC软件计算10％的细胞抑制浓度(IC10).免疫细胞化学染色观察榄香烯乳作用24h后A549细胞的Bcl-2、Bax、Survivin及VEGF蛋白的表达变化.结果:榄香烯乳对人肺腺癌A549细胞株增殖具有明显抑制作用,呈时间和剂量依赖性.榄香烯乳作用24h后IC10为43.49μg/ml,Bax蛋白表达增加,细胞质着色增强;Bcl-2蛋白表达下降,细胞质着色减弱;增殖蛋白Survivin和VEGF的表达下降,且具有药物浓度相关性.结论:榄香烯乳对人肺腺癌A549细胞株有明显的抑制作用,榄香烯乳可上调凋亡相关蛋白表达、诱导凋亡.