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.     

Effects of Selenium Dioxide on Apoptosis, Bcl-2 and P53 Expression, Intracellular Reactive Oxygen Species and Calcium Level in Three Human Lung Cancer Cell Lines

To evaluate the anti-tumor effects of SeO2 and its mechanisms on three human lung cancer cell lines. Methods: Three lung cancer cells A549, GLC-82 and PG were treated with 3-30 μmol/L SeO2. Flow cytometry was used to detect apoptosis, and analyze the changes of expression of p53 and Bcl-2, as well as ROS and Ca^2 level within cells. Results:SeO2 markedly inhibited cell proliferation and viability, and prompted apoptosis after 48 h treatment. SeO2 at 10 μmol/L induced 47.8% apoptosis in A549 cells, 40.8% in GLC-82 cells, 18.2% in PG cells. SeO2 at 30 μmol/L induced 37.8% apoposis in PG cells,but did not increase apoptotic raes in other two cells. SeO2 could down-regulate the mean fluorescent intensity of Bcl-2 from 65.8 to 9.6 in A549, but not in GLC-82 and in PG, cells, up-regulate wild type p53 level in all three cells. SeO2 decreased the ROS and Ca^2 level markedly within three tested cells. Conclusion: SeO2 showed anti-tumor effect via apoptosis pathway in three lung cancer cell lines. The decrease of ROS and Ca^2 level within cells as well as regulation of Bcl-2 and p53 expression may play important roles in above apoptotic procedure.     

The Effect of Curcumin on Proliferation and Apoptosis in LNCaP Prostate Cancer Cells

OBJECTIVE To observe the effect of curcumin on proliferation and apop-tosis in the prostate cancer LNCaP cell line. METHODS The AXSYMTM system luciferase method was used to examine the effect of various concentratious of curcumin on the content of prostate specific antigen (PSA) in prostate cancer LNCaP cells. A pGL3-PSA luciferase expression vector, containing 640 bp DNA of the PSA gene 5' -promoter region was constructed and transfected into the LNCaP cells with lipofectin. By measuring luciferase activity, the effect of 10 μmol/L, 20 μmol/L, 30 and 40 μmol/L curcumin on the promoter was studied. Effects on cell growth and apoptosis were analyzed by microscopy, the MTT colorimetric assay and flow cytometry. Western-blotting was used to measure expression of the androgen receptor (AR) in the LNCaP cells treated with different concentrations of curcumin. RESULTS The results showed that the expression of PSA was inhibited as curcumin reduced the activity of luciferase. Curcumin also caused a sigificant concentration-dependent decrease in AR expession measured by Western -blotting. Cell growth was inhibited and apoptosis was induced. CONCLUSION By inhibiting AR expression, curcumin reduced the function of the PSA promoter and inhibited PSA protein expression. Curcumin decreased the cellular proliferation and induced apoptosis in LNCaP cells in a concention-dependent manner.     

Down-Regulation of Notchl and NF-κB by Curcumin in Breast Cancer Cells MDA-MB-231

Objective:To test whether the down-regulation of Notch1 gene expression by curcumin could inhibit cell growth and induce apoptosis,which may be associated mechanistically with the down-regulation of NF-κB in breast cancer cells. Methods:Breast cancer cell lines MDA-MB-231 were cultured in vitro and treated with different dosages of curcumin(0,1.25,5.0,20.0μmol/L)for dose-dependent assay and different time(0,24,48,72 h)at the dosage of 5.0μmol/L for time course assay.The changes of the mRNA and protein expression of Notch1 and NF-κB were measured by RT-PCR and Western Blot,and MTT assay was used to measure the change of proliferation. Results:The mRNA and protein levels of Notch 1 and NF-κB were decreased significantly in human breast cancer cell line with the increase of dosage of curcumin(P＜0.05),and with the extension of time course(P＜0.05).These changes suggested a dose- and time-dependent manner.The proliferation rate of cells also was significantly inhibited(P＜0.05). Conclusion:The current results show that the Notch-1 signaling pathway is associated mechanistically with NF-κB activity during curcumin-induced cell growth inhibition and apoptosis of breast cancer cells.These results suggest that the down-regulation of Notch signaling by curcumin may be a novel strategy for the treatment of patients with breast cancer.     

Combined antitumor effect of ursolic acid and 5-fluorouracil on human esophageal carcinoma cell Eca-109 <Emphasis Type="Italic">in vitro</Emphasis>

Objective:To study the combined antitumor effect and possible mechanisms of ursolic acid with 5-fluorouracil (5-FU) on human esophageal carcinoma cell Eca-109 in vitro. Methods:Eca-109 cells were treated with ursolic acid (10-50 μmol/L) and/or 5-fluorouracil (48.0-768.8 μmol/L) for 48 h in vitro. And then cell proliferation was determined by MTT assay. Cell cycle and apoptosis rate were analyzed by flow cytometry (FCM). The morphological changes of apoptosis were observed by fluorescent microscopy. At last ...     

姜黄素诱导髓系白血病细胞凋亡的机制研究

Objective： To investigate the mechanism of apoptosis of myelocytic leukemia lines NB4, K562 and THP-1 cells induced by curcumin. Methods： After the cells were treated with curcumin at different concentration （25, 12.5, 6.25, 3.125, 0 μmol/L） for various times （0, 12, 24, 48 h）, flow cytometry （FCM） was used to determine the rate of apoptosis of cells. After the cells were treated with curcumin at 25 μmol/L for 24 h, flow cytometry was used to determine the expression level of Fas, and Western blot was performed to determine the expression of Caspase-8 and Caspase-9. Results： （1） Curcumin could induced the apoptosis of NB4, K562 and THP-1 cells in a time-and dose-dependent manner. After the cells were treated with curcumin at 25 μmol/L for 48 h, the rate of apoptosis of cells was over fifty percent. （2） Fas level showed remarkable increase （P 〈 0.01） after above cells were treated with 25 μmol/L curcumin for 24 h. （3） The apoptosis proteins of Caspase-8 and Caspase-9 were also increased obviously （P 〈 0.01） after the cells were treated with 25 μmol/L curcumin for 24 h. Conclusion： The molecular pathway of apoptosis of myelocytic leukemia lines induced by curcumin are concerned with death receptor and mitochondria.     

人参皂苷CK对人肺腺癌A549细胞株的增殖抑制作用及其机制

目的:探讨人参皂苷CK对人肺腺癌A549细胞增殖的影响及其作用机制。方法:不同浓度的人参皂苷CK作用于人肺腺癌A549细胞株,MTT比色法测定细胞增殖抑制率;倒置显微镜观察细胞形态学变化;流式细胞术分析细胞周期及细胞凋亡;ELISA法检测细胞内源性VEGF含量的变化。结果:人参皂苷CK对A549细胞增殖有抑制作用,其抑制作用呈浓度和时间依赖关系;倒置显微镜下可观察到细胞明显的形态学改变;流式细胞仪可检测到实验组细胞出现明显的凋亡峰,且细胞周期被阻滞在G0/G1期;实验组细胞培养液中的VEGF低于对照组(P＜0.05),且随着人参皂苷CK浓度增加和作用时间的延长,VEGF的含量降低(P＜0.05)。结论:人参皂苷CK可抑制人肺腺癌A549细胞的增殖并诱导其凋亡,并能抑制其内源性分泌VEGF。     

苹果多酚通过激活AMPK/SIRT1信号通路对LPS诱导的肺上皮细胞自噬反应的影响

目的:探讨苹果多酚通过调节腺苷酸活化蛋白激酶/沉默信息调节因子1（AMP-activated protein kinase/Sirtuin1,AMPK/SIRT1)信号通路对脂多糖（lipopolysaccharide,LPS）诱导的人肺泡上皮细胞（A549）自噬反应的影响。方法:使用不同浓度的苹果多酚提取物（apple polyphenol extract,APE）预处理A549细胞2 h后,LPS诱导A549细胞培养24 h,MTT法检测增殖活性,筛选APE最佳预处理浓度;将A549细胞分为对照组、LPS组（3 mg/L LPS）、LPS+APE组（3 mg/L LPS+20 μg/mL APE）、APE+Compound C组（3 mg/L LPS+20 μg/mL APE+50 μmol/L Compound C）,免疫荧光染色观察A549细胞自噬;流式细胞术检测A549细胞凋亡;Western blot法检测细胞中自噬相关蛋白及AMPK/SIRT1通路相关蛋白表达水平。结果:与对照组比较,经LPS诱导的A549细胞增殖活性、自噬水平、LC3Ⅱ/LC3Ⅰ、Beclin-1、SIRT1、p-ULK1/ULK1、p-AMPK/AMPK蛋白表达降低,p62蛋白表达及细胞凋亡率升高（P＜0.05）;与LPS组比较,LPS+APE组细胞增殖活性、自噬水平、LC3Ⅱ/LC3Ⅰ、Beclin-1、SIRT1、p-ULK1/ULK1、p-AMPK/AMPK蛋白表达水平显著升高,p62蛋白表达及细胞凋亡率显著降低（P＜0.05）;与LPS+APE组比较,APE+Compound C组A549细胞增殖活性、自噬水平、LC3Ⅱ/LC3Ⅰ、Beclin-1、SIRT1、p-ULK1/ULK1、p-AMPK/AMPK蛋白表达水平显著降低,p62蛋白表达及细胞凋亡率显著升高（P＜0.05）。结论:苹果多酚通过激活AMPK/SIRT1 信号通路提高LPS诱导的肺上皮细胞自噬,降低细胞凋亡。     

Melittin对非小细胞肺癌增殖、凋亡及PI3K／Akt信号通路的影响

目的 探讨Melittin对非小细胞肺癌（NSCLC）细胞增殖、凋亡及PI3K／Akt信号通路的影响。方法 分别采用0、10、20、50、100 μmol／L Melittin处理NSCLC细胞株A549、SPC-A1及人肺上皮细胞株16HBE 24、48、72和96 h后,采用四甲基偶氮唑盐（MTT）比色法检测各细胞株的增殖抑制率变化,同时采用流式细胞术Annexin-FITC／PI双染法及PI单染法检测不同浓度Melittin 处理24、48 h后的A549细胞凋亡及细胞周期情况,Western blotting检测不同浓度Melittin处理48 h后的A549细胞中PI3K／Akt信号通路相关蛋白（Akt和PTEN）及凋亡促进基因（caspase-9）的表达情况。结果 在10～100 μmol／L范围内,Melittin可呈剂量和时间依赖的方式提高A549、SPC-A1细胞的增殖抑制率,差异均有统计学意义（P＜0.05）,但对16HBE无细胞毒性作用（P＞0.05）;与0 μmol／L比较,除10 μmol／L Melittin处理24 h后的晚期凋亡率和G2／M期细胞比例无统计学差异（P＞0.05）,10～100 μmol／L的早、晚期凋亡率、G0／G1期细胞比例及PTEN和caspase-9蛋白水平均升高,S期、G2／M期细胞比例及Akt水平均降低,以上差异有统计学意义（P＜0.05）,且10～100 μmol／L范围内各浓度间的差异均有统计学意义（P＜0.05）。结论 Melittin可对NSCLC细胞有毒性作用,但对正常肺上皮细胞无影响,且可诱导A549细胞凋亡及细胞周期阻滞并抑制PI3K／Akt信号通路的激活。     

硫链丝菌肽下调FOXM1的表达对肺癌细胞生长及凋亡的影响

目的 探讨硫链丝菌肽（TST）对肺癌细胞A549增殖、凋亡及其对AG1478 （EGFR-TKI）药物敏感性的影响.方法 CCK-8法检测TST、AG1478单药及两药联用后A549细胞的增殖抑制率;Western blot检测TST对叉头转录因子M1（FOXM1）表达的影响;Caspase-3比色测定法检测TST对Caspase-3活化程度的影响;利用RNAi技术沉默A549细胞中FOXM1基因,检测FOXM1及增殖凋亡相关分子表达变化.结果 TST增加A549细胞对肺癌靶向药物AG1478的敏感性,其IC50值由（4.35±0.45） μmol/L降至（0.73±0.05） μmol/L（t=11.02,P＜0.05）;TST抑制FOXM1及下游c-Myc、Cyclin B1、Bel-2分子的表达,上调P21、Cleaved Caspase-3、Cleaved PARP表达的同时,呈时间及剂量依赖性诱导Caspase-3分子活化;沉默FOXM1后其下游分子c-Myc、Cyclin B1、Bcl-2、P21及Cleaved PARP的表达改变同TST作用后相似,细胞中Cleaved Caspase-3的荧光表达明显增多.结论 TST介导的FOXM1下调可抑制A549细胞增殖,诱导其凋亡,并增加其对AG1478的药物敏感性.     

miRNA-139-5p通过靶向调控CXCR4/CXCL12信号通路逆转非小细胞肺癌A549细胞顺铂耐药

目的:探讨miRNA-139-5p对非小细胞肺癌A549细胞顺铂（cisplatin,DDP）耐药的影响,及其可能的分子机制。方法:采用DDP浓度递增法诱导A549细胞建立DDP耐药细胞株A549/DDP,将miR-139-5p mimics、无义序列（mimics-NC）、CXCR4过表达质粒（pcDNA3.1-CXCR4）、pcDNA3.1空载质粒（Vector）转染至A549/DDP细胞中,将细胞分为mimics-NC组（转染无义序列）、mimics组（转染miR-139-5p mimics）、mimics+Vector组（共转染miR-139-5p mimics和空载质粒）和mimics+CXCR4组（共转染miR-139-5p mimics和CXCR4过表达质粒）,另设置空白对照组（blank）。不同浓度DDP处理,MTT法检测细胞增殖活性,并计算IC50值和耐药指数（resistance index,RI）;qRT-PCR法检测细胞中miR-139-5p和CXCR4 mRNA表达水平;流式细胞术检测细胞凋亡率;Western blot法检测细胞中耐药相关蛋白P-糖蛋白（P-gp）、多药耐药相关蛋白1（MRP1）及CXCR4/CXCL12信号通路相关蛋白表达水平;双荧光素酶报告基因实验验证miR-139-5p与CXCR4的靶向关系。结果:不同浓度DDP处理24 h后,耐药株A549/DDP及其亲本A549细胞IC50值分别为（208.87±27.89）μmol/L和（31.66±6.30）μmol/L,RI=6.59。与亲本A549细胞比较,耐药株A549/DDP中miR-139-5p的表达水平明显降低（P＜0.05）,而CXCR4 mRNA和蛋白表达水平明显升高（P＜0.05）。与mimics-NC组比较,mimics组A549/DDP细胞增殖活性明显降低（P＜0.05）,细胞凋亡率明显升高（P＜0.05）,细胞中CXCR4 mRNA和蛋白以及P-gp、MRP1、PI3K（p110α）和p-AKT/AKT等蛋白表达水平显著降低（P＜0.05）。与mimics+Vector组比较,mimics+CXCR4组A549/DDP细胞增殖活性显著升高（P＜0.05）,细胞凋亡率显著降低（P＜0.05）,而细胞中CXCR4、P-gp、MRP1、PI3K（p110α）和p-AKT等蛋白表达水平显著升高（P＜0.05）。双荧光素酶报告基因实验证实,miR-139-5p靶向负调控CXCR4表达。结论:miRNA-139-5p通过靶向下调CXCR4表达,提高非小细胞肺癌DDP耐药细胞株A549/DDP对DDP的药物敏感性。     

华蟾素介导miR-497-5p/VEGFA通路调控肺癌细胞的增殖、凋亡及血管生成

目的:探讨华蟾素介导miR-497-5p/VEGFA通路对肺癌细胞增殖、凋亡及血管生成的影响。方法:选取肺癌细胞株A549、H460为研究对象,以不同浓度华蟾素（0、25、50、75、100、125、150 μg/mL）作用细胞株,采用MTT检测细胞活力。随后,设置组别为空白组、华蟾素组（100 μg/mL华蟾素）、华蟾素+inhibitor NC组、华蟾素+miR-497-5p inhibitor组,通过MTT检测细胞活力;克隆形成实验检测克隆形成能力;流式细胞术检测细胞凋亡;Western blot检测细胞中VEGF、VEGFA蛋白表达;RT-qPCR检测细胞中miR-497-5p表达;并采用荧光素酶报告实验确定miR-497-5p靶向VEGFA。结果:随着华蟾素浓度的升高,A549、H460细胞增殖活力明显下降（P＜0.01）;与空白组相比,华蟾素组A549、H460细胞克隆形成能力明显降低、细胞凋亡明显增加、VEGF和VEGFA蛋白表达明显降低、miR-497-5p mRNA表达明显升高（P＜0.01）;荧光素酶报告实验显示miR-497-5p靶向VEGFA;与华蟾素+inhibitor NC组相比,华蟾素+miR-497-5p inhibitor组A549、H460细胞中miR-497-5p mRNA表达明显降低、VEGF和VEGFA蛋白表达明显升高、细胞克隆形成能力明显增加、细胞凋亡明显被抑制、细胞增殖活力明显增加（P＜0.05）。结论:华蟾素可能通过调控miR-497-5p/VEGFA通路从而抑制肺癌细胞增殖和血管生成,并诱导细胞凋亡。     

塞来昔布抑制人肺腺癌细胞的增殖和表皮生长因子受体的表达*

目的:探讨不同浓度的环氧化酶-2 抑制剂塞来昔布（Celecoxib ）在不同时间点对肺腺癌A549 细胞株增殖和表皮生长因子受体（EGFR）表达的影响。方法:人肺腺癌A549 细胞株培养于含10% 胎牛血清RPMI1640培养基中。实验细胞分组如下:A组,正常对照;B 组,Celecoxib（12.5 μ mol/L）;C 组Celecoxib（25μ mol/L）;D 组Celecoxib（50μ mol/L）,E 组Celecoxib（75μ mol/L）,均以RPMI1640培养液配置。使用不同浓度塞来昔布（12.5、25、50和75μ mol/L）处理肺癌A549 细胞24、48、72h 后,四甲基偶氮唑盐比色法（MTT）测定细胞增殖抑制率;AnnexinⅤ/PI 染色法与Hoechst33258 染色法检测细胞凋亡率;流式细胞仪检测药物作用周期;Real-time RT-PCR 法检测EGFR mRNA 的表达情况。结果:塞来昔布明显抑制了A549 细胞的生长,呈时间、剂量依赖性。塞来昔布组细胞凋亡率明显高于正常对照组（P<0.01）,且呈剂量依赖性,S 期细胞比例明显减少（P<0.01）,G0/G1 期细胞比例明显增加（P<0.01）,提示塞来昔布能将大多数A549 细胞阻滞于G0/G1 期。塞来昔布组细胞EGFR mRNA 表达明显减弱（P<0.05）,且呈浓度依赖性,各浓度间差异具有统计学意义（P<0.05）。 结论:塞来昔布显著抑制A549 细胞生长,可能机制是通过促进凋亡、增强G0/G1 期阻滞、下调细胞中EGFR mRNA 的表达,从而为应用塞来昔布治疗肺腺癌,以及塞来昔布和表皮生长因子受体抑制剂联用提供了一定的实验依据。      

全反式维甲酸增强顺铂对A549 细胞化疗敏感性及对Survivin mRNA 和COX-2 mRNA表达的影响

目的:体外观察全反式维甲酸（all-trans retinoic acid ,ATRA）增强顺铂（cisplatin,DDP ）对人类非小细胞肺癌细胞株A549 细胞的增殖抑制及对凋亡抑制蛋白Survivin mRNA和环氧化酶-2（cyclooxygenase- 2,COX-2）mRNA 表达的影响。方法:应用不同浓度组DDP（0.5、5、50mg/L）、ATRA（0.1、1、10μ mol/L）以及联合用药组（ATRA 1 μ mol/L,DDP 5mg/L）,处理肺腺癌细胞株A549 细胞,采用四甲基偶氮唑盐（MTT）比色法观察不同浓度DDP 组、不同浓度ATRA 组及联合用药组对A549 细胞生长的影响;应用实时荧光定量聚合酶链反应（real-time polymerase chain reaction ,RT-PCR）检测DDP 组、ATRA 组及联合用药组处理前后A549 细胞中Survivin mRNA和COX-2 mRNA 表达变化;应用流式细胞术观察DDP 组、ATRA 组及联合用药组处理前后细胞凋亡率。结果:与空白对照组相比,单独应用DDP 、ATRA 处理A549 细胞均诱导细胞凋亡,且呈浓度依赖性。与单独应用DDP 的作用相比,联合用药组可更显著抑制A549 的增殖,增加细胞的凋亡率（P<0.05）,并增强对A549 细胞Survivin mRNA和COX-2 mRNA表达的抑制作用（P<0.05）;并且,流式细胞术测定结果显示联合用药组的早期凋亡率（7.37± 3.83）% 、中晚期凋亡率（34.37±2.08）% 、继发性坏死率（7.44± 0.46）% 均较单独应用DDP 组高（3.55± 0.75）% 、（6.62± 0.33）% 、（3.03± 0.05）% ,P 均<0.05。结论:全反式维甲酸能够明显提高非小细胞肺癌对顺铂的敏感性,其机制可能与抑制非小细胞肺癌细胞Survivin mRNA和COX-2 mRNA 的表达有关。      

HIF-1α高表达对苯代谢物诱导K562细胞毒性的影响

目的：研究缺氧诱导因子-1α（HIF-1α）高表达对苯代谢物1,4-苯醌、氢醌、苯酚诱导K562细胞毒性的影响。方法：用不同浓度的1,4-苯醌（0、10、20、40、80 μmol/L）、氢醌（0、10、20、40、80 μmol/L）、苯酚（0、1、1.5、2、2.5、5 mmol/L）分别染毒对照组K562细胞及高表达HIF-1α的K562细胞24 h,MTT法检测细胞增殖情况,PI/FITC Annxein V双染结合流式细胞术检测细胞凋亡率,碘化丙啶结合流式细胞术检测细胞周期。结果：MTT实验结果显示,1,4-苯醌染毒后,两株细胞均出现增殖率下降且呈剂量效应关系,1,4-苯醌浓度为80 μmol/L时,高表达HIF-1α的K562细胞增殖率高于对照组K562细胞（P < 0.05）。氢醌和苯酚在较高浓度染毒后,对照组K562细胞亦出现增殖抑制,而高表达HIF-1α的K562细胞增殖无明显抑制。流式细胞术结果显示,1,4-苯醌染毒后,两株细胞的细胞凋亡率增加且呈剂量效应关系。20 μmol/L浓度1,4-苯醌染毒时,高表达HIF-1α的K562细胞较对照组K562细胞凋亡减弱（P < 0.05）。氢醌和苯酚染毒后,两株细胞的凋亡率与未染毒组比较,差异均无统计学意义（P均 > 0.05）,高表达HIF-1α的K562细胞的凋亡率较对照组K562细胞亦无显著差异。细胞周期检测结果显示,3种苯代谢物均可引起K562细胞周期阻滞在G0/G1期或S期。结论：3种苯的代谢物中,1,4-苯醌对K562细胞的毒性大于氢醌和苯酚,HIF-1α高表达可降低苯代谢物引起的细胞毒性,其作用的发挥可能是通过调节细胞增殖及凋亡而实现。     

葫芦素E对非小细胞肺癌细胞的生长抑制作用

目的:体外观察葫芦素E（cucurbitacin E,CuE）对非小细胞肺癌细胞系A549增殖的影响及分子作用机制。方法:采用MTT法检测不同浓度 CuE（0、1、10、100以及1000nmol/L）处理A549细胞24、48和72小时后的细胞增殖情况。流式细胞仪检测CuE对A549细胞凋亡的影响。 Western blot法检测被处理细胞中p-STAT3、p-Raf-1、p-MEK1/2、p-ERK1/2、Bcl-2、Fas蛋白表达水平的变化。结果:CuE可显著抑制A549细胞的增殖（P＜0.05）,且呈时间和浓度依赖性。流式细胞仪检测显示随着CuE作用浓度的逐渐升高（0、100、200、400nmol/L）,A549细胞凋亡率由（4.63±0.70）%分别提高到（6.80±0.10）%、（20.53±0.49）%、（24.57±0.55）%,差异有统计学意义（P均<0.05）。Western blot结果显示CuE处理A549细胞,可降低p-STAT3、p-Raf-1、p-MEK1/2、p-ERK1/2、Bcl-2蛋白表达水平,增强Fas蛋白表达水平,且上述作用随CuE浓度升高而增强。结论:CuE可显著抑制A549细胞的增殖并诱导凋亡,其作用机制与阻断STAT3和Raf/MEK/ERK信号通路,同时激活Fas信号通路有关。