Flavopiridol诱导耐阿霉素尤文肉瘤细胞株VH-64／ADR凋亡及作用机制的研究

目的：探讨细胞周期蛋白酶抑制剂flavopiridol（FP）对耐阿霉素尤文肉瘤细胞增殖抑制及凋亡诱导的作用机制。方法：采用MTT法测定阿霉素（ADM）及falvopifidol对VH-54／ADR细胞的半数抑制浓度（IC50）,计算耐药倍数;流式细胞计数仪（FCM）检测falvopiridol给药后VH-64／ADR细胞周期的变化;Western—blotting方法检测细胞中Bcl-2、pro—caspase-3、活化型多聚ADP核糖多聚酶（PARP-85）蛋白的表达。结果：flavopiridol可抑制尤文肉瘤耐阿霉素细胞株VH／ADR的细胞增殖,其效果呈时间及浓度相关性（P〈0．05）。flavopiridol给药后,耐药细胞株VH-54／ADR的细胞凋亡率明显高于对照组（P〈0．05）;bcl-2、pro—casepase-3表达下调,而活性型PARP表达上调。结论：FP可有效诱导VH-64／ADR细胞发生凋亡,其机制可能与线粒体信号传导途径有关。     

Flavopiridol诱导耐阿霉素尤文肉瘤细胞株VH-64/ADR 凋亡及作用机制的研究

目的:探讨细胞周期蛋白酶抑制剂flavopiridol(FP)对耐阿霉素尤文肉瘤细胞增殖抑制及凋亡诱导的作用机制.方法:采用MTT法测定阿霉素(ADM)及falvopiridol对VH-64/ADR细胞的半数抑制浓度(IC50),计算耐药倍数;流式细胞计数仪(FCM)检测falvopiridol给药后VH-64/ADR细胞周期的变化;Western-blotting方法检测细胞中Bcl-2、pro-caspase-3、活化型多聚ADP核糖多聚酶(PARP-85)蛋白的表达.结果:flavopiridol可抑制尤文肉瘤耐阿霉素细胞株VH/ADR的细胞增殖,其效果呈时间及浓度相关性(P<0.05).flavopiridol给药后,耐药细胞株VH-64/ADR的细胞凋亡率明显高于对照组(P<0.05);bcl-2、pro-casepase-3表达下调,而活性型PARP表达上调. 结论:FP可有效诱导VH-64/ADR细胞发生凋亡,其机制可能与线粒体信号传导途径有关.     

脂氧合酶抑制剂NDGA对胰腺癌细胞PCNA-1增殖和凋亡的影响

目的:探讨脂氧合酶抑制剂NDGA对人胰腺癌细胞株PCNA-1生长抑制、诱导凋亡及其对bcl-2、bax表达的影响.方法:采用MTT法检测NDGA对胰腺癌细胞株PCNA-1增殖活性的影响,流式细胞术检测NDGA处理的胰腺癌细胞株PCNA-1的细胞周期及凋亡相关蛋白bcl-2、bax的表达.结果:NDGA抑制胰腺癌细胞株PCNA-1的增殖活性,呈剂量依赖效应关系;细胞经100μmol/L的NDGA处理后G0/G1期细胞减少(P＜0.05)、S期细胞增多(P＜0.05),G2/M期细胞无明显变化;细胞经100μmol/L的NDGA处理48h后bcl-2蛋白与对照组相比表达下调(P＜0.01)、bax蛋白与对照组相比表达上调(P＜0.01).结论:NDGA对胰腺癌细胞株PCNA-1有抑制增殖、诱导其凋亡作用,诱导细胞凋亡的机制可能与细胞凋亡相关基因bcl-2表达下调、bax表达上调有关.     

天花粉蛋白对宫颈癌HeLa细胞凋亡及bax 、bcl-2 基因表达的影响

 目的 研究天花粉蛋白对人宫颈癌HeLa细胞的诱导凋亡作用并探讨其对凋亡相关基因bax和bcl-2表达的影响。方法 不同浓度天花粉蛋白分别处理HeLa细胞24～72h后，MTT法检测细胞的生长活性，显微镜观察细胞形态，流式细胞仪检测细胞周期，WesternBlot检测凋亡相关蛋白bax，bcl-2的表达。结果 显微镜下观察到细胞圆缩，染色体凝聚等凋亡细胞的形态学改变，流式细胞仪直方图上亦出现特征性的亚二倍体峰，随着天花粉蛋白浓度的增加，bax基因的表达增加而bcl-2的表达减少。结论 天花粉蛋白对HeLa细胞的生长具有抑制作用，可诱导宫颈癌HeLa细胞发生凋亡，bcl-2蛋白的减少与bax蛋白表达增多可能是HeLa细胞凋亡的机制之一。     

脂氧合酶抑制剂NDGA对胰腺癌细胞PCNA-1增殖和凋亡的影响

目的：探讨脂氧合酶抑制剂NDGA对人胰腺癌细胞株PCNA-1生长抑制、诱导凋亡及其对bcl-2、bax表达的影响。方法：采用MTT法检测NDGA对胰腺癌细胞株PCNA-1增殖活性的影响,流式细胞术检测NDGA处理的胰腺癌细胞株PCNA-1的细胞周期及凋亡相关蛋白bcl-2、bax的表达。结果：NDGA抑制胰腺癌细胞株PCNA-1的增殖活性,呈剂量依赖效应关系;细胞经100μmol／L的NDGA处理后G0／G1期细胞减少（P〈0．05）、S期细胞增多（P〈0．05）,G2／M期细胞无明显变化;细胞经100μmol／L的NDGA处理48h后bcl-2蛋白与对照组相比表达下调（P〈0．01）、bax蛋白与对照组相比表达上调（P〈0．01）。结论：NDGA对胰腺癌细胞株PCNA-1有抑制增殖、诱导其凋亡作用,诱导细胞凋亡的机制可能与细胞凋亡相关基因bcl-2表达下调、bax表达上调有关。     

三氧化二砷诱导尤文肉瘤细胞凋亡及对EWS-FLi1融合蛋白的影响

目的:探讨三氧化二砷(Arsenic trioxide,As2O3)诱导尤文肉瘤细胞凋亡及对融合蛋白EWS-FLi1表达的影响.方法:应用噻唑蓝(MTT)法、形态学观察、原位末端标记法(TUNEL)、流式细胞术(FCM)观察As2O3对体外生长的尤文肉瘤RD-ES细胞系生物行为的影响;应用半定量RT-PCR测定应用As2O3前后c-myc基因mRNA水平的变化;应用免疫细胞化学及固定化蛋白印迹法(Western blot)观察用药前后EWS-FLi1融合蛋白表达水平的变化.结果:As2O3对体外生长的RD-ES细胞系具有明显抑制作用,并可诱导细胞凋亡.c-myc基因mRNA表达水平和EWS-FLi1融合蛋白表达量随As2O3作用时间延长逐渐降低.结论:常规治疗浓度的As2O3对体外生长的尤文肉瘤细胞具有明显的杀伤作用,其作用机制与改变线粒体膜通透性和抑制EWS-Fli1融合蛋白、降低c-myc基因表达有关.     

云南元宝枫黄酮诱导个旧肺鳞癌细胞YTMLC凋亡的实验研究

目的研究云南元宝枫黄酮对个旧肺鳞癌细胞(YTMLC)凋亡诱导作用及相关基因表达的影响,为开发应用元宝枫黄酮提供实验依据。方法采用四甲基偶氮唑蓝(MTT)比色法检测元宝枫黄酮对YTMLC细胞的生长抑制作用,流式细胞术TUNEL法检测元宝枫黄酮对YTMLC细胞凋亡的影响,RT-PCR检测元宝枫黄酮对YTMLC细胞 p53、p21、bcl-2、bax和caspase-3基因表达的影响。结果元宝枫黄酮作用YTMLC细胞48 h后,IC50为（108.53±8.22）mg/L。流式细胞术显示元宝枫黄酮既可以诱导YTMLC细胞凋亡,也可以引起YTMLC细胞坏死。元宝枫黄酮对p53、p21、bax和caspase-3的基因表达均有明显上调作用;对bcl-2基因表达有下调作用。结论云南元宝枫黄酮可以抑制个旧肺鳞癌细胞(YTMLC)体外生长,引起肿瘤细胞坏死,诱导肿瘤细胞凋亡,其诱导肿瘤细胞凋亡的可能机制是通过上调p53、p21、bax和caspase-3基因的表达,下调bcl-2基因表达。     

拓扑替康诱导卵巢癌COC1/ DDP 细胞凋亡的分子机制初步探讨

  目的 探讨拓扑替康(TPT)对人卵巢癌顺铂耐药细胞株COC1／DDP的杀伤和诱导凋亡活性及其作用机制。方法 MTT比色法与软琼脂克隆形成测定TPT对人卵巢癌顺铂耐药细胞株COC1／DDP的杀伤效应；TUNEL法和流式细胞仪研究TPT对靶细胞的凋亡诱导作用；Western blot检测TPT对COC1／DDP细胞内bcl-2、bax和caspase-3基因表达的影响以及caspase-3活性的改变。结果 TPT对COC1／DDP细胞有明显细胞毒性作用，不仅有剂量依赖性，也存在明显的时间依赖性；COC1／DDP细胞在TPT作用后出现特征性凋亡形态特征，且凋亡率由8．54％上升为23．16％(P<0．05)。TPT不影响COC1／DDP细胞内bcl-2蛋白表达，却明显增加19ax蛋白和caspase-3蛋白表达，并提高caspase-3活性。结论 TPT对人卵巢癌顺铂耐药细胞株COC1／DDP有明显的杀伤和促凋亡作用，其机制可能依赖于细胞内bax蛋白表达增高和caspase-3的活化。     

四硫化四砷抑制人胃癌SGC7901细胞增殖及其作用机制

目的：探讨四硫化四砷（As4S4）对人胃癌细胞系SGC7901增殖抑制作用及其作用机制.方法：MTT法检测四硫化四砷对体外培养SGC7901细胞的抑制作用,透射电镜观察细胞形态学改变,流式细胞仪检测细胞周期的变化,RT-PCR法检测bcl-2和bax mRNA的表达,Western blot法检测bcl-2和bax蛋白的表达.结果：四硫化四砷具有体外抑制SGC7901细胞增殖的作用,能诱导细胞凋亡,细胞中bcl-2的表达降低,bax 的表达增强.结论：四硫化四砷具有抑制胃癌细胞系SGC7901细胞生长的作用,其机制可能与诱导细胞凋亡和调节bcl-2与bax表达有关.     

法尼基转移酶抑制剂ManumyCin诱导HepG2细胞凋亡的研究

目的:研究法尼基转移酶抑制剂Manumycin对人肝癌HepG2细胞的抗肿瘤作用,并探讨其诱导凋亡的分子机制。方法:采用MTT(Methythiazolyltetrazolium)法观察法尼基转移酶抑制剂Manumycin对肝癌细胞株HepG2细胞增殖的抑制作用,荧光显微镜、DNA凝胶电泳、流式细胞术等技术检测细胞凋亡,应用Westernblot方法检测bcl-2、p53、bax的蛋白水平变化。结果:法尼基转移酶抑制剂Manumycin能明显抑制HepG2细胞的生长且呈浓度依赖性,其IC50为(17.65±0.58)μmol/L。荧光显微镜检查显示Manumycin处理的HepG2细胞DAPI染色后,细胞核内可见浓染致密的颗粒荧光,典型细胞可见新月型改变,固缩或片段化的核。DNA凝胶电泳可见典型的DNA梯形带。流式细胞DNA直方图上出现典型的亚二倍体“凋亡峰”,细胞凋亡与Manumycin作用的时间和浓度相关。Manumycin能时间依赖性地诱导HepG2细胞发生G2/M期阻滞。Manumycin处理HepG2细胞后,Westernblot检测结果显示p53蛋白表达明显增加,而bcl-2蛋白和bax蛋白表达无明显变化。结论:法尼基转移酶抑制剂Manumycin对人肝癌细胞株HepG2有强烈的细胞毒作用,其分子机制可能是诱导HepG2细胞凋亡。Manumycin诱导HepG2细胞凋亡与bcl-2蛋白和bax蛋白表达水平无关,而p53蛋白表达水平的上调可能在此过程中起了一定     

Flavopiridol,a cyclin dependent kinase (CDK) inhibitor,induces apoptosis by regulating Bcl-x in oral cancer cells

Flavopiridol is a synthetic flavone that inhibits tumor growth by suppressing cyclin-dependent kinases (CDKs). We have investigated effects of flavopiridol in oral squamous cell carcinoma (OSCC). Flavopiridol was found to inhibit the growth of OSCC cells in a time- and dose-dependent manner. Induction of apoptosis was observed in all cells showing accumulated cells with sub-G(1) DNA contents, DNA fragmentations, and PARP cleavages. While Bcl-2 and Bax expression did not change, Bcl-x(L) was down regulated and Bcl-xs was up-regulated after being exposed to flavopiridol. Flavopiridol treatments also resulted in remarkable reductions of cyclin A, cyclin B, and cyclin D1 expressions. We also found that expression levels of CDK activation kinase and CDC25C were reduced, and p34 inactive form CDK2 were up-regulated. Our data indicate that flavopiridol has growth inhibition activities against OSCC. Flavopiridol not only inhibits CDKs directly, but it also inhibits the CDKs activation pathway and activates the Bcl-x apoptotic pathway.     

四嗪二甲酰胺诱导肺癌细胞株EBC-1凋亡的作用及其机制

目的 研究四嗪二甲酰胺(ZGDHu-1)诱导肺癌细胞株EBC-1凋亡的作用及分子机制.方法 将不同浓度的ZGDHu-1与EBC-1细胞在体外培养,采用5′-溴-2′脱氧尿苷(BrdU)-酶联免疫吸附法(ELISA)观察ZGDHu-1对EBC-1细胞的增殖抑制作用;采用Annexin V/PI双标记染色与ELISA法测定凋亡细胞核小体等技术检测ZGDHu-1诱导EBC-1细胞凋亡的作用;采用流式细胞术检测经ZGDHu-1作用后EBC-1细胞磷酸化p38MAPK和Stat3表达的变化;采用Western blot法检测Bcl-2、Bax、Fas、p53、caspase-3蛋白表达的变化.结果 ZGDHu-1能抑制EBC-1细胞增殖,并呈现作时间和剂量依赖性,作用24、48和72 h后的IC50分别为(295±25)ng/ml、(112±8)ng/ml和(23±2)ng/ml.经ZGDHu-1作用后,EBC-1细胞中的Annexin V+/PI-细胞升高,细胞内核小体含量显著增加,二者均呈现剂量依赖性.EBC-1细胞与50、200和500 ng/ml的ZGDHu-1培养48 h后,磷酸化p38MAPK的表达率分别为67.4%、88.2%和91.1%,空白对照组为10.6%;而磷酸化Stat3的表达率分别为56.5%、43.6%和34.6%,空白对照组为89.1%.Western blot检测结果显示,随药物作用浓度的升高,Bax、Fas和p53蛋白的表达显著上调,Bcl-2的表达没有变化,caspase-3蛋白的表达则明显下调.结论 ZGDHu-1能显著抑制EBC-1细胞增殖,并诱导其凋亡.Fas介导的线粒体途径可能是ZGDHu-1诱导EBC-1细胞凋亡的通路之一,p38MAPK和Stat3激活也参与了ZGDHu-1诱导EBC-1细胞凋亡的过程.     

Zoledronic acid, a third-generation bisphosphonate, inhibits cellular growth and induces apoptosis in oral carcinoma cell lines

Bisphosphonates (BPs) inhibit bone resorption by preventing osteoclast maturation and apoptosis induction. Recently, BPs have also been shown to have antitumor effects against various types of carcinomas in vitro and in vivo. In this study, we investigated the antitumor effect of zoledronic acid (ZOL), a third generation bisphosphonate, on proliferation, cell cycle and apoptosis of oral cancer cells. Direct antitumor effects of ZOL against four oral carcinoma cell lines (squamous cell carcinoma, HSC3, HSC4, SCCKN; salivary adenocarcinoma, HSY) were measured by WST assay. Apoptosis-related molecules were analyzed by Western blot analysis and cell cycle was analyzed by flow cytometry. ZOL had a dose-dependent antitumor effect in the four oral cancer cell lines. ZOL activated caspase-3, -8 and -9 and induced cellular apoptosis. Western blot analysis showed that ZOL increased cleaved anti-human poly(ADP-ribose) polymerase expression and decreased Bcl-2 and Bid expression. Treatment with ZOL increased the number of cells in apoptosis, sub G1 phase and S phase, and reduced the number of cells in the G0/G1 and G2/M phase in a concentration-dependent manner. ZOL inhibits cell proliferation and induces apoptosis of oral cancer cells in vitro. These findings suggest that ZOL might be beneficial in the treatment of oral carcinoma patients.     

BH3模拟物S1诱导人类白血病细胞株K562凋亡的作用机制

 【摘要】　  目的　以人类白血病细胞株K562为研究对象,探讨BH3模拟物S1 诱导人类白血病细胞凋亡的机制。方法　通过XTT法检测S1 作用下K562细胞的生存率; S1作用不同时间,流式细胞术检测细胞凋亡率;分光光度法检测Caspase-3、-8、-9激活;免疫共沉淀检测S1作用后bax、bak释放情况。结果　与对照组相比S1能够以时间和浓度依赖的方式诱导K562细胞凋亡,24 h的IC50值为13.5 μmol／L;流式细胞术结果显示,S1 处理12 h后K562细胞出现大量早期凋亡,时间延长至24 h后,晚期凋亡比例显著增加;S1通过激活Caspase-3、-9而不是Caspase-8诱导K562细胞通过内源凋亡通路进行凋亡;免疫共沉淀实验检测5 μmol／L的S1处理8 h后K562细胞中的抗凋亡蛋白bcl-2和mcl-1受到S1的拮抗,促凋亡蛋白bax和bak分别从抗凋亡蛋白bcl-2和mcl-1上得到释放。结论　S1可能通过拮抗bcl-2、mcl-1蛋白释放bax、bak诱导人类白血病细胞凋亡。     

Cyclin-dependent kinase inhibitor, flavopiridol, induces apoptosis and inhibits tumor growth in drug-resistant osteosarcoma and Ewing's family tumor cells

Multimodal therapies play important roles in the treatment of osteosarcoma (OS) and Ewing's family of tumors (EFTs), two most frequent malignant bone tumors. Although the clinical outcome of primary OS and EFTs is greatly improved, the relapsed cases often are associated with multidrug resistance of the tumors and the prognosis of these patients is still poor. Flavopiridol, a pan cyclin-dependent kinase (CDK) inhibitor is a novel antitumor agent that can induce cell cycle arrest and apoptosis in many cancer cells. However, there have been no studies about the effects of flavopiridol on drug-resistant OS and EFTs. Here, we demonstrated that flavopiridol induced the cleavage of poly-ADP-ribose polymerase (PARP) in a time and dose dependent manner in adriamycin-resistant OS and EFTs cells expressing P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP(1)) as effectively as in their parental cells. Our data also showed that flavopiridol caused the release of mitochondrial cytochrome c and the activation of caspase-9, caspase-8 and caspase-3, with an increase ratio of the proapoptotic protein level (Bax) to the antiapoptotic protein level (Bcl-2 and Bcl-X(L)), while apoptosis was inhibited by pan caspase inhibitor (Z-VAD-FMK) and caspase-3 inhibitor (Z-DEVD-FMK), not by caspase-8 inhibitor (Z-IETD-FMK). The treatment with flavopiridol further inhibited the tumor growth in mouse models of the drug-resistant OS and EFTs. These results suggest that flavopiridol might be promising in clinical therapy for the relapsed OS and EFTs.     

新型多胺缀合物NNAMB诱导K562细胞凋亡及其机制

目的 探讨新型多胺缀合物NNAMB诱导K562细胞凋亡及其分子机制.方法 采用二苯基溴化四氮唑蓝(MTT)法、台盼监拒染法检测细胞活力;Hoechst33258染色观察细胞形态变化;流式细胞仪检测细胞周期变化、凋亡率、线粒体膜电位的变化;Western blot检测caspase-3、caspase-8、caspase-9和cytochrome c的表达.结果 NNAMB抑制K562细胞的生长,并呈现剂量及时间依赖性.随着NNAMB浓度的增加和作用时间的延跃,Sub-G1期细胞明显增加,线粒体膜电位下降.经NNAMB处理后的K562细胞中,可见到明显的凋亡细胞.蛋白印迹检测表明,NNAMB可诱导caspase-3、easpase-9的活化及线粒体cytochrome c释放到胞浆中,但caspase-8的表达无明显变化.结论 NNAMB能显著抑制K562细胞增殖,并可通过内源性线粒体途径诱导细胞凋亡.     

Induction of apoptosis and inhibition of c-erbB-2 in breast cancer cells by flavopiridol.

Flavopiridol is a flavone that inhibits several cyclin-dependent kinases and exhibits potent growth-inhibitory activity against a number of human tumor cell lines, both in vitro and when grown as xenografts in mice. It is presently being investigated as a novel antineoplastic agent in the primary screen conducted by the Developmental Therapeutics Program, National Cancer Institute. Because breast cancer is the most common cancer and second leading cause of cancer-related deaths in women in the United States, we investigated whether flavopiridol could be an effective agent against a series of isogenic breast- cancer cell lines having different levels of erbB-2 expression and differential invasion and metastatic characteristics. Flavopiridol was found to inhibit the growth of MDA-MB-435 (parental) and 435.eB (stable transfectants) cells that were established by transfecting c-erbB-2 cDNA into MDA-MB-435. Induction of apoptosis was also observed in these cell lines when treated with flavopiridol, as measured by DNA laddering, PARP, and CPP32 cleavages. We also found modest up-regulation of Bax and down-regulation of Bcl-2, but there was a significant down-regulation of c-erbB-2 in flavopiridol-treated cells. Gelatin zymography showed that flavopiridol inhibits the secretion of matrix metalloproteinase (MMP; MMPs 2 and 9) in the breast cancer cells and that the inhibition of c-erbB-2 and MMPs may be responsible for the inhibition of cell invasion observed in flavopiridol-treated cells. Collectively, these molecular effects of flavopiridol, however, were found to be independent of c-erbB-2 overexpression, suggesting that flavopiridol may be effective in all breast cancer. From these results, we conclude that flavopiridol inhibits the growth of MDA-MB-435 breast cancer cells, induces apoptosis, regulates the expression of genes, and inhibits invasion and, thus, may inhibit metastasis of breast cancer cells. These findings suggest that flavopiridol may be an effective chemotherapeutic or preventive agent against breast cancer.     

蛇床子素诱导HL-60细胞凋亡及其分子机制研究

目的 研究蛇床子素对急性髓系白血病HL-60细胞增殖、凋亡的影响,并探讨其作用的分子机制.方法 CCK8实验检测蛇床子素对HL-60细胞的增殖抑制作用,Hoechst染色观察药物8h作用后细胞的形态学变化,流式细胞术检测细胞凋亡情况,反转录-聚合酶链式反应（RT-PCR）检测HL-60细胞的Bcl-2、Bax mRNA表达变化,Western bolt检测HL-60细胞的活性caspase-3、caspase-8、caspase-9、Fas、FasL蛋白表达变化.结果 蛇床子素可明显抑制HL-60细胞增殖并诱导其发生凋亡,抑制率最高达（90.7±4.5）％,F=138.46,P=0.000;总凋亡率为33.6％,F=27.75,P=0.006.诱导后Bcl-2 mRNA表达下调,Bax mRNA表达上调,Bax/Bcl-2比值升高（F=210.12,P=0.000）,活性caspase-3、caspase-8、caspase-9、Fas、FasL蛋白表达水平随药物作用时间延长而升高.结论 蛇床子素可抑制HL-60细胞增殖并诱导凋亡,其诱导凋亡机制与同时激活线粒体途径和死亡受体途径相关.