苯丁酸钠对人肝癌细胞分化及P~(21WAF1/CIP1)表达的调控

目的:探讨苯丁酸钠诱导人肝癌细胞Bel7402,HepG2生长抑制、分化和细胞周期阻滞,以及对抑癌基因P21WAF1 /CIP1表达的影响。方法:培养Bel7402,HepG2,应用MTT比色法观察苯丁酸钠对Bel7402,HepG2的生长抑制作用,倒置相差显微镜观察细胞形态改变,流式细胞术分析细胞周期,以RTPCR检测Bel 7402,HepG2细胞中P21WAF1 /CIP1基因表达水平,WESTERN印记法检测P21WAF1 /CIP1蛋白的表达。结果:苯丁酸钠 2, 4, 8mmol·L-1处理 72h后Bel 7402, HepG2 的抑制率分别为 28. 43 %,57. 61 %, 71. 32 %和 27. 42 %, 57. 11 %, 70. 31 %处理后的细胞成纤维母细胞样改变,细胞阻滞于G期,P21WAF1 /CIP1基因和蛋白表达水平均增强。结论:苯丁酸钠抑制 2种人肝癌细胞株的生长,诱导部分人肝癌细胞分化,使细胞阻滞于G1期,苯丁酸钠能诱导P21WAF1 /CIP1基因的表达,增加P21WAF1 /CIP1蛋白的表达水平。     

蛇葡萄素改变Bcl-2/Bax表达和激活caspase-3诱导人肝癌细胞Bel-7402凋亡

目的探讨蛇葡萄素在体外诱导人肝癌细胞株Bel-7402的凋亡作用及其可能机制。方法以不同浓度的蛇葡萄素作用于体外培养的人肝癌细胞株Bel-7402,应用MTT法检测培养24、48和72h的细胞生长情况;荧光染色观察细胞核的形态学改变;琼脂糖凝胶电泳分析细胞DNA变化;流式细胞仪检测细胞凋亡率;Western blot检测细胞caspase-3、Bcl-2和Bax的表达情况。结果蛇葡萄素对Bel-7402细胞的生长有明显的增殖抑制作用,呈浓度和时间依赖性。24、48、72h的IC50值分别是89.6±16.1、36.2±6.5和15.3±3.0mg·L-1。经荧光染色后可观察到典型的凋亡小体。细胞DNA电泳后呈现出凋亡细胞典型的DNAl adder。流式细胞术检测细胞凋亡率呈时间和浓度依赖性。caspase-3和Bcl-2蛋白表达量逐渐降低,Bax蛋白表达量逐渐增加,呈明显的浓度依赖性。结论蛇葡萄素能诱导体外培养的人肝癌Bel-7402细胞凋亡,其作用具有时间和浓度依赖性。下调Bcl-2、上调Bax表达,活化caspase-3是蛇葡萄素诱导Bel-7402细胞凋亡的可能机制之一。     

Anti-tumor effect of germacrone on human hepatoma cell lines through inducing G2/M cell cycle arrest and promoting apoptosis

Germacrone is one of the main bioactive components in the traditional Chinese medicine Rhizoma curcuma. In this study, the anti-proliferative effect of germacrone on the human hepatoma cell lines and the molecular mechanism underlying the cytotoxicity of germacrone were investigated. Treatment of human hepatoma cell lines HepG2 and Bel7402 with germacrone resulted in cell cycle arrest and apoptosis in a dose-dependent manner as measured by MTT assay, flow cytometric and fluorescent microscopy analysis, while much lower effect on normal human liver cell L02 was observed. Flow cytometric analysis revealed that germacrone induced G2/M arrest in the cell cycle progression that was associated with an obvious decrease in the protein expression of cyclin B1 and its activating partner CDK1 with concomitant inductions of p21. Hoechst 33258 and Annexin V/PI staining results showed that the total cell number in apoptosis associated with a dose-dependent up-regulation of Bax and down-regulation of Bcl-2/Bcl-xl was increased. In the meantime, the up-regulation of p53 and reactive oxygen species increase were observed, which suggested that germacrone might be a new potent chemopreventive drug candidate for liver cancer via regulating the expression of proteins related to G2/M cell cycle and apoptosis, and p53 and oxidative damage may play important roles in the inhibition of human hepatoma cells growth by germacrone.     

苯丁酸钠体外对人肝癌细胞分化、抑癌基因表达的调控

目的探讨苯丁酸钠(SPB)诱导人肝癌细胞Bel-7402生长抑制、分化和细胞周期阻滞,以及对抑癌基因P21WAF1/CIP1、P27表达的影响。方法培养Bel-7402,应用溴化四唑蓝比色法观察SPB对Bel-7402的生长抑制作用,倒置相差显微镜观察细胞形态改变,流式细胞术分析细胞周期,以逆转录聚合酶链反应(RT-PCR)检测Bel-7402细胞中P21WAF1/CIP1、P27mRNA表达水平。结果SPB处理后Bel-7402的生长缓慢,处理后的细胞成纤维母细胞样改变,细胞阻滞于G1期(78.8±3.6,50.6±4.0;P<0.05),P21WAF1/CIP1基因表达水平增强(0.08±0.13,0.72±0.14;P<0.05),P27mRNA的表达明显增强(0.09±0.11,0.61±0.12;P<0.05)。结论SPB抑制人肝癌细胞株Bel-7402的生长,诱导人肝癌细胞分化,使细胞阻滞于G1期,SPB诱导抑癌基因P21WAF1/CIP1、P27表达。     

莪术提取物对人肝癌细胞株Bel-7402抑制作用的体外研究

目的:研究本室制备的莪术提取物在体外对人肝癌细胞株Bel-7402细胞周期进程的干扰及其可能的机制。方法:通过用四甲基偶氮唑蓝(MTT)比色法、集落形成实验观察莪术提取物在体外对Bel-7402细胞株的抑制作用;流式细胞仪分析其细胞周期的改变。结果:莪术提取物对Bel-7402细胞株的抑制作用呈剂量依赖性;可使Bel-7402细胞的S期细胞比例和G2/M期细胞比例升高,G0/G1期细胞比例下降。结论:莪术提取物对人肝癌细胞株Bel-7402有细胞毒作用,其细胞毒作用可能与阻止细胞周期有关。     

Pro-apoptotic and microtubule-disassembly effects of ardisiacrispin (A+B), triterpenoid saponins from Ardisia crenata on human hepatoma Bel-7402 cells

Ardisiacrispin (A+B) is a mixture of ardisiacrispins A and B, derived from Ardisia crenata with a fixed proportion (2:1). The present study was conducted to investigate its anticancer activity on human cancer cells and its underlying mechanism of action. The (IC50)s of ardisiacrispin (A+B) on proliferation of several human cancer cell lines were in the range of 0.9-6.5 microg/ml by sulphorhodamine B-based colorimetric assay, in which Bel-7402 was the most sensitive cell line. Moreover, ardisiacrispin (A+B) induced dose-dependent apoptosis in Bel-7402 cells at doses of 1-10 microg/ml by flow cytometry, and resulted in the changes of the mitochondrial membrane depolarization, membrane permeability enhancement, and nuclear condensation in a dose-dependent manner through high-content screening analysis. Furthermore, ardisiacrispin (A+B) could disassemble microtubule in Bel-7402 cells; the fluorescence intensity of microtubules decreased at the concentration of 5-20 microg/ml. These findings suggest that ardisiacrispin (A+B) could inhibit the proliferation of Bel-7402 cells by inducing apoptosis and disassembling microtubule.     

Alteronol inhibits proliferation in HeLa cells through inducing a G1-phase arrest

Objectives Alteronol is a novel compound purified from fermentation products of a microorganism in the bark of the yew tree. The study was designed to evaluate the anticancer effects of alteronol. Methods Human cervical carcinoma cell line HeLa was cultured in vitro. The cell viability was evaluated by using sulforhodamine B assay. The cell cycle distribution was analysed by flow cytometry. The level of cyclin D1 protein was evaluated using Western blot analysis. The changes in cyclinD1, CDK4 and p21 were detected by ELISA assay and the changes in G1‐related regulators were detected by RT‐PCR assay. Key findings Our data showed that alteronol inhibited the proliferation of HeLa cells and induced G1 phase arrest. Downregulation of the mRNA levels of CDK2, CDK4 and cyclin D1 and upregulation of p21 in alteronol‐treated cells were observed. Conclusions Downregulation of the mRNA levels of CDK2, CDK4 and cyclin D1 and upregulation of p21 might be a possible mechanism for the inhibition of proliferation induced by alteronol in HeLa cells.     

Pro-apoptotic and microtubule-disassembly effects of ardisiacrispin (A+B), triterpenoid saponins from Ardisia crenata on human hepatoma Bel-7402 cells.

Ardisiacrispin (A+B) is a mixture of ardisiacrispins A and B, derived from Ardisia crenata with a fixed proportion (2:1). The present study was conducted to investigate its anticancer activity on human cancer cells and its underlying mechanism of action. The (IC(50))s of ardisiacrispin (A+B) on proliferation of several human cancer cell lines were in the range of 0.9-6.5 mug/ml by sulphorhodamine B-based colorimetric assay, in which Bel-7402 was the most sensitive cell line. Moreover, ardisiacrispin (A+B) induced dose-dependent apoptosis in Bel-7402 cells at doses of 1-10 mug/ml by flow cytometry, and resulted in the changes of the mitochondrial membrane depolarization, membrane permeability enhancement, and nuclear condensation in a dose-dependent manner through high-content screening analysis. Furthermore, ardisiacrispin (A+B) could disassemble microtubule in Bel-7402 cells; the fluorescence intensity of microtubules decreased at the concentration of 5-20 mug/ml. These findings suggest that ardisiacrispin (A+B) could inhibit the proliferation of Bel-7402 cells by inducing apoptosis and disassembling microtubule.     

Oroxylin A induces G2/M phase cell-cycle arrest via inhibiting Cdk7-mediated expression of Cdc2/p34 in human gastric carcinoma BGC-823 cells

We reported previously that oroxylin A, a natural product isolated from Scutellariae Radix, was a potent apoptosis inducer of human hepatoma HepG2 cells. In this study, cell-cycle arrest of BGC-823 human gastric carcinoma cells caused by oroxylin A has been investigated. Based on our 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay and flow cytometric analysis, treatment of BGC-823 cells with growth suppressive concentrations of oroxylin A caused an irreversible arrest in the G2/M phase of the cell cycle. Western blot analysis demonstrated that oroxylin A-induced cell-cycle arrest in BGC-823 cells was associated with a significant decrease in cdc2/p34, cyclin B1 and cyclin A expression. In addition, oroxylin A-treated cells decreased the expression of Cdk7, which was responsible for the low expression of M phase promoting factor (cyclin B1/Cdc2). The results suggested that oroxylin A induced G2/M phase cell-cycle arrest via inhibiting Cdk7-mediated expression of Cdc2/p34 in human gastric carcinoma BGC-823 cells.     

榄香烯衍生物诱导HeLa细胞凋亡的实验研究

目的研究榄香烯衍生物(榄香烯哌嗪)对人宫颈癌细胞HeLa体外增殖的抑制作用及其作用机制。方法采用SRB法考察榄香烯哌嗪对多种人癌细胞体外增殖的抑制作用。普通光学显微镜及荧光显微镜观察榄香烯哌嗪对HeLa细胞形态的影响,利用流式细胞仪检测HeLa细胞凋亡及细胞周期变化情况。结果榄香烯哌嗪对HeLa、HepG2、SGC-7901及Bel-7402细胞有较强的体外增殖抑制作用。光学显微镜和荧光显微镜观察榄香烯哌嗪10μmol.L-1处理的HeLa细胞,细胞体积变小、细胞核皱缩致密,可见凋亡小体。此外,榄香烯哌嗪可将HeLa细胞阻滞于G0/G1期,且随药物作用时间延长或剂量增加,DNA直方图上可见渐强的SubG1峰。结论榄香烯哌嗪可诱导人宫颈癌HeLa细胞凋亡,且具有细胞周期阻滞作用。     

调节自噬提高人肝癌Bel-7402/FU细胞株对5-氟尿嘧啶的敏感性

目的：探讨细胞自噬对肝癌Bel-7402／FU细胞5-氟尿嘧啶敏感性的影响。方法：选取Bel-7402、Bel-7402／FU细胞株,分为对照组、5-氟尿嘧啶组、自噬抑制剂3-甲基腺苷组以及5-氟尿嘧啶＋3-甲基腺苷组,MTT法了解抑制细胞自噬对肝癌5-氟尿嘧啶IC50值的影响;流式细胞术检测抑制细胞自噬对细胞凋亡的影响;GFP-LC3质粒转染观察细胞浆中GFP-LC3分布情况。结果：Bel-7402细胞株与Bel-7402／FU细胞株5-氟尿嘧啶IC50值分别为4．66、68．14μg／mL,凋亡率分别为13．809／6、1.09％。3-甲基腺苷联合5-氟尿嘧啶作用后Bel-7402细胞株与Bel-7402／FU细胞株的氟尿嘧啶IC50值分别为4．31、29．44μg／mL,凋亡率分别为13．82％、6．86％。在3-甲基腺苷作用下,Bel-7402／5-FU细胞株5-氟尿嘧啶诱导的点状样GFP-LC3的细胞数量减少。结论：抑制细胞自噬可降低Bel-7402／FU对5-氟尿嘧啶IC50值,诱导细胞凋亡,从而有效地逆转Bel-7402／FU对5-氟尿嘧啶耐药。     

雷公藤甲素对宫颈癌Hele细胞增殖的抑制作用

目的研究雷公藤甲素对宫颈癌Hele细胞增殖的抑制作用。方法采用MTT方法检测雷公藤甲素对体外培养的宫颈癌Hele细胞增殖的影响,运用流式细胞术检测细胞周期,RT-PcR分析细胞周期蛋白B1（cyclinBl）mRNA的表达;Western-blot检测cyclinBl、P34cdc2。和磷酸化P34cdc2（phosphorcdc2）蛋白的表达。结果雷公藤甲素浓度依赖性（0．5～4．0／lg．mL-1）抑制体外培养的宫颈癌Hele细胞,干扰Hele细胞周期。细胞周期阻滞于s期和G：／M期,s期和G2／M期的百分率上升;同时G0／G1细胞百分率降低;RT-PCR结果显示,雷公藤甲素（0．5～4．0／ag．mL-1）显著抑制cyclinB1mRNA的表达;Western-blot结果显示,雷公藤甲素（0．5～4．0gg．mL-1）作用24h后cyclinB1蛋白表达开始不同程度降低,P34cdc2。变化较小,雷公藤甲素作用12h后磷酸化P34cdc2。蛋白水平明显改变。结论雷公藤甲素可以显著抑制宫颈癌Hele细胞体外增殖,其机制与细胞周期阻滞于s期和影响细胞周期因子cyclinBl的表达和改变P34cdc2。磷酸化有关。     

Induction of G0/G1 arrest and apoptosis by 3-hydroxycinnamic acid in human cervix epithelial carcinoma (HeLa) cells

The present studies were undertaken to analyze the factors regulating 3-hydroxycinnamic acid-induced apoptosis and cell cycle arrest. Treatment of human cervix HeLa cells with 3-hydroxycinnamic acid induced apoptosis and G0/G1-phase arrest. The percentage of apoptosis induced by 3-hydroxycinnamic acid in HeLa cells was increased with incubation time. The results also demonstrated that 3-hydroxycinnamic acid increased the expression of p53, caspase-3, Bax and cyclin B. These results demonstrated that 3-hydroxycinnamic acid induced apoptosis through p53- and caspase-3-dependent pathways.     

美洲大蠊提取物对人肝癌细胞Bel-7402作用机制的研究

目的探讨美洲大蠊提取物对人肝癌细胞Bel-7402的作用机制。方法 MTT比色法观察美洲大蠊提取物对人肝癌细胞Bel-7402增殖的影响,AnnexinV-FITC/PI双染色法研究美洲大蠊提取物对人肝癌细胞Bel-7402凋亡的影响,流式细胞术检测线粒体膜电位,DNA Ladder实验检测细胞凋亡,蛋白印迹法检测Bax、Bcl-2、Caspase-9、Caspase-3、Caspase-8蛋白的表达。结果美洲大蠊提取物可抑制人肝癌细胞Bel-7402增殖,IC50为28.2μg.mL 1,并可诱导人肝癌细胞Bel-7402凋亡,降低线粒体膜电位。DNA Ladder实验可见明显的梯形电泳图谱,蛋白印迹法显示Bax、Caspase-9、Caspase-3蛋白表达增强,Bcl-2蛋白表达减弱,Caspase-8蛋白表达无明显变化。结论美洲大蠊提取物可通过线粒体途径诱导人肝癌细胞Bel-7402凋亡。     

高车前素对肝癌细胞增殖的抑制作用及作用机制研究

目的研究高车前素对肝癌细胞增殖的抑制作用,检测高车前素对Janus蛋白酪氨酸激酶/信号转导和转录活化蛋白(JAK/STAT3)信号通路的影响。方法采用四甲基偶氮唑盐(MTT)法检测不同浓度高车前素(1,5,10,25,50,100,200μmol/L)对Bel-7402肝癌细胞株增殖的影响。高车前素(5,25,100μmol/L)预处理Bel-7402肝癌细胞48 h,采用Transwell小室检测各组细胞的体外侵袭能力,蛋白印迹法检测p-STAT3、Twist1和Bcl-2蛋白表达差异。结果高车前素能浓度依赖性抑制Bel-7402肝癌细胞株增殖。高车前素(25,100μmol/L)预处理能显著减弱Bel-7402肝癌细胞的体外侵袭力,抑制p-STAT3、Twist1和Bcl-2蛋白表达(P<0.05)。结论高车前素可能通过JAK/STAT3通路,抑制p-STAT3、Twist1蛋白活性表达,从而抑制抗凋亡的Bcl-2蛋白表达,来发挥有效抑制肝癌细胞增殖的作用。     

白藜芦醇烟酸酯抑制人肝癌细胞HepG2增殖并诱导细胞的凋亡

目的：观察白藜芦醇的修饰物白藜芦醇烟酸酯（ResT）对人肝癌细胞HepG2生长增殖的影响及诱导凋亡的作用。方法：用不同浓度的ResT处理HepG2细胞，MTT法检测ResT对HepG2细胞生长增殖的抑制作用；应用Hochest荧光染色法观察凋亡细胞的发生；流式细胞术（FCM）检测分析细胞周期和细胞凋亡率；比色法测定Caspase-3酶活性。结果：ResT抑制HepG2细胞的增殖并呈现一定的量效和时效关系，HepG2细胞与ResT作用后出现典型的凋亡细胞形态改变，FCM分析显示大部分细胞阻滞于G1期，S期细胞比例降低。且药物作用组出现凋亡峰。药物作用12、24、48h后，细胞的凋亡率分别为8．7％、21．1％、和32.7％。显示ResT诱导的细胞凋亡作用随时间的延长而增加，同时Caspase-3酶活性显著增强。结论：ResT可抑制人肝癌细胞HepG2的生长增殖，其作用机制之一可能与阻滞细胞于G1期及诱导细胞凋亡有关。     

Apoptosis induction and cell cycle perturbation in human hepatoma hep G2 cells by 10-hydroxycamptothecin

10-Hydroxycamptothecin (HCPT), a DNA topoisomerase I inhibitor, is an antitumor alkaloid isolated from a Chinese tree, Camptotheca acuminata, and exhibits a remarkable antihepatoma effect. We studied HCPT to determine whether or not its anti-hepatoma activity occurs through apoptosis induction and cell cycle disturbance using the MTT method, DAPI staining, agarose gel electrophoresis and flow cytometric analysis. The results showed that HCPT inhibited proliferation of human hepatoma Hep G2, Bel-7402 and Bel-7404 cells at an optimal concentration of 0.1 microg/ml. This growth inhibition was dose and time dependent, and was accompanied by evidence of apoptotic changes and cell cycle perturbation in Hep G2 cells. Chromatin condensation and nuclear fragmentation were observed in Hep G2 cells by fluorescence microscopy. Agarose gel electrophoresis showed internucleosomal DNA fragmentation ('ladder pattern') of Hep G2 cells following treatment with HCPT, in a concentration- and time-dependent manner. Flow cytometry showed that HCPT induced a massive hypodiploid cell population and arrested cells in G2/M phase (at low dose) or in S phase (at high dose) in Hep G2 cells. The results of this study suggest that the anti-hepatoma effect of HCPT may result from apoptosis induction and cell cycle disturbance.     

Ras/ERK1 pathway regulation of p27KIP1-mediated G1-phase cell-cycle arrest in cordycepin-induced inhibition of the proliferation of vascular smooth muscle cells

Cordycepin, the main constituent of Cordyceps militaris, demonstrated an anti-atherogenic effect in experimental animals. However, the effects of cordycepin on cell-cycle regulation and the signaling pathway in vascular smooth muscle cells (VSMC) remain largely unknown; therefore, unexpected roles of cordycepin-induced inhibition in VSMC growth were investigated. Mechanisms in cordycepin-treated VSMC were examined via an MTT assay, a thymidine uptake experiment, FACS analysis, immunoblot analysis, kinase assay, immunoprecipitation assay, and transient transfection assays. Cordycepin inhibited cell growth, induced G1-phase cell-cycle arrest, down-regulated cyclins and cyclin-dependent kinase (CDK) expression, and up-regulated p27KIP1 expression in VSMC. Cordycepin induced activation of JNK, p38MAPK and ERK1/2. Blocking of the ERK function using either ERK1/2-specific inhibitor U0126 or a small interfering RNA (si-ERK1) reversed p27KIP1 expression, inhibition of cell growth, and decreased cell-cycle proteins in cordycepin-treated VSMC. Ras activation was increased by cordycepin. Transfection of cells with dominant negative Ras (RasN17) mutant genes rescued cordycepin-induced ERK1/2 activity, increased p27KIP1 expression, inhibited cell proliferation, and reduced cell cycle proteins. In conclusion, our findings indicate that Ras/ERK1 pathways participate in p27KIP1-mediated G1-phase cell-cycle arrest induced by cordycepin via a decrease in cyclin/CDK complexes in VSMC.     

Anticancer activity and mechanisms of norcantharidin-Nd3II on hepatoma

Norcantharidin (NCTD), a demethylated form of cantharidin, is currently used as an anticancer drug in China, but five newly synthesized derivatives have not been tested for antitumor efficacy. In this study, we investigated the in-vitro and in-vivo activity of five derivatives on Bel-7402, HeLa and PC-3M1E8 cell lines on a sulfarhodamine B assay. All of the derivatives showed significant antiproliferative activity, hence we elected to study further one of them, NCTD-Nd3II, in an in-vivo mouse model, and to examine its effects on cell cycle and protein expression. NCTD-Nd3II inhibited H22 tumors in mice in a dose-dependent manner with low toxicity. Flow cytometry results showed that apoptosis and G2/M cell cycle arrest contributed to the cytotoxic and cytostatic effects of NCTD-Nd3II. Further studies showed that Bax and p21 protein expression was upregulated, whereas cyclin B1, Cdc-2 and Bcl-2 protein expression was downregulated. Our findings show that NCTD-Nd3II might be a promising chemotherapeutic agent for hepatomas.