片仔癀对人卵巢癌OVCAR-3细胞增殖、凋亡及周期的影响

目的：研究片仔癀对人卵巢癌细胞株OVCAR-3增殖抑制作用,及其对细胞周期、细胞凋亡的影响。方法：采用MTT法观察片仔癀对人卵巢癌细胞株OVCAR-3细胞的增殖抑制率,流式细胞仪检测细胞凋亡及细胞周期,westem—blot检测相关蛋白的表达。结果：片仔癀以剂量依赖式抑制人卵巢癌细胞株OVCAR-3细胞增殖,片仔癀250、500、1000μg·mL-1作用于OVCAR-3细胞24h后,其早期凋亡率分别为6．6％、30．9％、43．2％,而对照组为0％,其诱导凋亡作用呈现剂量依赖性;细胞积聚在G0／G1期,同时S期细胞比例减少;Akt、PARP、CDK6表达下调。结论：片仔癀可以抑制OVCAR-3细胞增殖及诱导细胞凋亡作用,并能阻滞细胞于G0／G1期,有望成为卵巢癌治疗药。     

CDK1 siRNA干扰在Taxol诱导细胞凋亡中的作用

目的研究转染细胞周期依赖性蛋白激酶1（cyclin．dependent kinase1,CDK1）siRNA、以及转染后进行凋亡刺激对细胞周期和凋亡的影响,探讨CDK1在细胞凋亡中的确切作用,揭示细胞周期与细胞凋亡协调的分子机制。方法以人宫颈癌细胞株HeLa细胞为研究对象,脂质体转染CDK1siRNA,转染后48h加紫杉醇（Tax01）（20μg／m1）刺激凋亡,Western印迹检测CDK1和抗凋亡蛋白BCL2表达,AnnexinV／PI法检测细胞的凋亡,流式细胞仪分析DNA含量检测细胞周期。结果转染CDK1 siRNA后,CDK1蛋白的表达下降,细胞周期G2／M期比例增加,细胞凋亡率与对照相比没有明显升高。只加Taxol刺激12h后细胞凋亡率增加并伴有S期和G2／M期比例增加。转染CDKlsiRNA后再用Taxol刺激,其细胞凋亡率没有明显改变,G2／M期阻滞效应也没有叠加。BCL2蛋白只在加Taxol刺激组表达下降,与CDK1表达减少没有相关性。结论siRNA沉默导致的CDK1表达降低只导致细胞周期G2／M期阻滞,没有引起细胞凋亡;CDK1的表达降低对紫杉醇所诱导的细胞周期阻滞和细胞凋亡效应没有明显影响。     

乳杆菌DM9811发酵液提取物中RNA组分对人结肠癌细胞系HT-29增殖影响及分子机制研究

目的观察乳杆菌DM9811发酵液提取物中RNA组分对人结肠癌细胞系HT-29增殖的影响,探讨其对肠道肿瘤细胞的作用及其分子机制,为阐明乳杆菌与宿主相互作用规律的分子机制奠定基础。方法应用MTT方法研究不同时间不同浓度RNA组分对HT-29增殖的影响,应用流式细胞术、RT-PCR研究RNA组分对HT-29细胞周期的影响。结果乳杆菌DM9811发酵液中RNA组分能抑制HT-29细胞增殖,并呈现出时间-剂量依赖性;RNA组分作用于HT-29细胞24 h、48 h时,细胞周期G0/G1期所占比例明显上升,S期所占比例明显降低(P0.01),细胞周期调控因子CDK6、p27Kip1、p53的表达升高,CDK2、CDK4、PCNA的表达降低。结论乳杆菌DM9811代谢产物RNA在体外具有抑制癌细胞周期活性。     

芒柄花黄素在体外对内皮细胞细胞周期的影响

目的观察芒柄花黄素在体外对人脐静脉内皮细胞（HUVEC）增殖及周期的影响。方法采用四甲基偶氮唑蓝（MTT）法检测不同芒柄花黄素对HUVEC增殖的影响,流式细胞术检测细胞周期,Western blot检测cyclin D1蛋白表达水平。结果芒柄花黄素呈剂量依赖性促进HUVEC增殖。且药物作用后,S期细胞比例增加,cyclin D1蛋白表达升高。结论芒柄花黄素对人脐静脉内皮细胞有明显的促进增殖作用,可通过上调cyclin D1蛋白表达增加S期细胞比率。     

孕激素诱导cyclin G1在小鼠子宫内膜上皮细胞的表达及其对细胞增殖的影响

本文在体外培养条件下研究卵巢激素诱导小鼠子宫内膜上皮细胞cyclin G1的表达及细胞增殖和细胞周期进程的变化,以探讨孕激素依赖的细胞周期调控因子cyclin G1对子宫内膜上皮细胞增殖的负调控作用.原代培养小鼠子宫内膜上皮细胞,待其生长汇合后分为4组:对照组(C组)、雌激素组(E组)、孕激素组(P组)、雌、孕激素共同作用组(EP组).加入相应激素作用24 h后,用细胞免疫化学方法检测各组细胞cyclin G1的表达水平:四甲基偶氮唑蓝(MTT)比色法检测各组细胞活力,间接观察子宫内膜上皮细胞的增殖情况;用流式细胞仪检测分布在细胞周期各时相的子宫内膜上皮细胞所占百分数.细胞免疫化学结果显示,cyclin G1在C组和E组子宫内膜上皮细胞上无明显表达,而在P组和EP组子宫内膜上皮细胞中表达明显,且定位于细胞核内.MTT法结果显示,与C组相比,E组细胞活力明显增高,而P组和EP组的细胞活力均明显下降,表明雌激素能促进子宫内膜上皮细胞增殖,而孕激素则具有抑制子宫内膜上皮细胞增殖的作用.流式细胞术检测显示,与C组相比,E组中处于S期的子宫内膜上皮细胞百分数增多;P组与EP组中处于S期的子宫内膜上皮细胞百分数明显减少,而处于G1期的细胞百分数和G2/M期的细胞百分数则明显增加.上述结果提示,孕激素依赖的cyclin G1可能通过阻滞细胞周期进程来参与孕激素对子宫内膜上皮细胞增殖的负调控作用.     

抑制VEGF基因表达对乳腺癌细胞细胞周期的影响

目的：研究针对VEGF基因的siRNA（small interferenceRNA）对乳腺癌MCF-7细胞细胞周期的影响。方法：依据Promega公司在网上提供的设计软件,设计针对VEGF基因的siRNA,合成DNA模板,体外转录合成siRNA。脂质体转染法将合成的siRNA转染入MCF-7细胞,以未转染细胞以及错义序列siRNAscr转染细胞为对照。用细胞计数法检测siRNA对MCF-7细胞增殖的影响：流式细胞法检测细胞周期变化,RT—PCR法比较转染前后p21、CyclinDl表达水平的变化,Westemblot检测转染前后磷酸化ERK的表达。结果：细胞计数法结果显示,转染24h后siRNA明显抑制MCF-7细胞增殖,转染48h后,抑制效率稳定。siRNA转染后能有效地抑制MCF-7细胞的增殖,阻滞细胞周期于G0／G1期,S期细胞明显减少,G0／G1期细胞比例逐渐增多;p21mRNA表达显著上调,抑制CyclinD1mRNA及磷酸化ERK蛋白的表达。结论：体外转录合成的siRNA可能通过上调细胞周期蚤白激酶抑制剂p21的表达,下调CyclinDl及磷酸化ERK的表达,将细胞周期阻滞于G0／G1期,从而显著抑制MCF-7细胞的增殖。     

二甲双胍对低级别非侵袭性膀胱肿瘤细胞增殖的影响

目的:初步探讨降糖药物二甲双胍对膀胱肿瘤细胞253J的作用及其相关作用机制。方法:采用Cell Counting Kit-8(CCK-8)试剂盒分析二甲双胍对膀胱肿瘤细胞增殖的影响。应用流式细胞仪检测二甲双胍对细胞周期及凋亡的影响。并通过免疫印迹方法检测相关蛋白确定可能参与其中的信号分子。结果:在各时间点(24小时,48小时,72小时)二甲双胍处理组与对照组相比膀胱肿瘤细胞的增殖受到明显抑制(P0.01或P0.05);与对照组比较,二甲双胍处理组G0/G1期细胞比例上升,S期细胞比例下降(P0.01或P0.05);免疫蛋白印迹发现,二甲双胍处理组中的磷酸化AMP激活的蛋白激酶(AMP-activated protein kinase,AMPK)表达升高,同时细胞周期蛋白D1(cyclin D1)的表达下降(P0.01或P0.05)。结论:体外实验中二甲双胍能够明显抑制膀胱肿瘤细胞的增殖,通过下调cyclin D1的表达诱导细胞周期停滞于G0/G1期。这些结果表明二甲双胍可能成为治疗膀胱癌的潜在药物。     

人白血病细胞系KG-1a中肿瘤干细胞样亚群细胞的初步研究

探讨人白血病细胞系KG-1a中是否存在具有肿瘤干细胞样生物学特性的亚群细胞.瑞氏染色和吖啶橙染色分别观察白血病细胞系KG-1a细胞形态和RNA含量:流式细胞术检测细胞周期分布;免疫组化和流式细胞术检测KG-1a细胞CD34的表达;流式细胞术检测CD34 CD38-亚群细胞;烟酸己可碱Hoechst33342染色后用荧光显微镜观察KG-1a细胞中侧群(side population,SP)样细胞所占比例.结果显示,白血病细胞系KG-1a细胞核仁易见,形态原始;部分细胞RNA含量低,细胞处于G0/G1期的比例占15.5%.绝大多数细胞的胞浆和胞膜皆表达CD34抗原,KG-1a中CD34 细胞占96.3%,CD34 CD38-亚群细胞占7.02%;SP样细胞大致比例为7.60%.本研究表明.人白血病细胞系KG-1a中存在具有肿瘤干细胞样生物学特性的亚群细胞.     

斑褐孔菌石油醚提取物体外抗肿瘤活性研究

探讨斑褐孔菌石油醚提取物(PEFP)体外抗肿瘤活性及其机制。采用磺酰罗丹明染色法(SRB法)考察PEFP对人肝癌细胞SMMC-7721、人胃癌细胞SGC-7901、人喉癌上皮细胞Hep-2增殖的影响。倒置相差显微镜、透射电镜观察PEFP作用SMMC-7721后的细胞形态及超微结构的变化;流式细胞术检测PEFP作用SMMC-7721后细胞周期的改变情况。实验结果显示PEFP对上述三种人恶性肿瘤细胞均表现出明显的抑制效果,且呈剂量效应关系,其半数抑制浓度(IC50)分别为52.72、69.18、58.88μg/mL。取1/2 IC50浓度的PEFP作用于SMMC-7721 48 h后,细胞形态结构及细胞周期发生改变,G0/G1期细胞增多,S期细胞明显减少。PEFP可能通过阻滞SMMC-7721细胞周期于G0/G1期来抑制肿瘤细胞的增殖,具有较明显体外抗肿瘤活性。     

脱氧雪腐镰刀菌烯醇对胃癌细胞增殖及细胞周期的影响

探讨脱氧雪腐镰刀菌烯醇（DON）对体外培养的两株胃癌细胞（SGC-7901和BGC-823）增殖及细胞周期的影响。采用细胞培养、噻唑蓝（MTF）比色法、流式细胞定量检测（FCM）、蛋白质免疫印迹（Western印迹）以及免疫细胞化学染色（ICH）等方法,研究不同浓度DON处理72h对体外培养胃癌细胞的增殖、细胞周期及细胞周期相关蛋白—细胞周期蛋白依赖性激酶抑制蛋白（CKIs）P21WAF/CIP1和细胞周期蛋白E（cyclin E）表达的影响。MTT法检测结果显示DON可明显抑制两株胃癌细胞的增殖,SGC．7901和BGC．823细胞100、500、1000ug／L DON处理组的增殖抑制率分别为4．28％、36．20％、45．35％和14．89％、32．30％、51．61％。FCM检测结果显示,给予1000ug／LDON处理72h可使两株细胞周期阻滞在GffM期。在100～1000u扎浓度范围内,两株细胞P21WAF／CIP1表达量均高于对照组,P21WAF／CIP1的表达与DON浓度呈显著正相关关系（SGC-7901细胞：r=0．886,P〈0．01;BGC-823细胞：r=0．943,P〈0．01）;两株细胞的细胞周期蛋白E表达量均低于对照组,与DON浓度有明显剂量依赖关系（SGC．7901细胞：r=-0．923,P〈0．01;BGC-823细胞：r=-0．854,P〈0．01）。Western印迹及免疫细胞化学检测进一步证实了DON处理对蛋白质表达的影响。综合结果表明,DON可抑制体外培养胃癌细胞的增殖活性,G2／M期阻滞、P21WAF/CIP1表达增高及细胞周期蛋白E表达下降可能是DON抑制胃癌细胞增殖的可能机制,DON对分化程度不同的胃癌细胞的影响没有明显差别。     

Effect of protocatechuic acid from Alpinia oxyphylla on proliferation of human adipose tissue-derived stromal cells in vitro

The effect of protocatechuic acid (PCA) from Alpinia oxyphylla and catapol from Rehmannia on the proliferation capacity of human adipose tissue-derived stromal cells (hADSCs) was investigated in vitro. Cell counts showed that treatment of hADSCs with PCA for 48 h increased the cell number in a dose-dependent manner, while no obvious effect of catapol on the proliferation of hADSCs was observed. In addition, the cell number of hADSCs treated by 1.5 mM PCA increased in a time-dependent manner. The flow cytometric analysis of DNA content demonstrated the cell cycle progress from the G0/G1 phase to the S phase. Western blot analysis revealed the elevated expression of cyclin D1 in hADSCs induced by PCA treatment. Cyclin D1-siRNA transfection significantly inhibit the promotion of cell proliferation by PCA. Furthermore, the flow cytometric analysis of the cell surface antigens and the multidifferential potential tests of PCA-treated hADSCs showed that the cells retained their functional characteristics of multipotential mesenchymal progenitors. It is concluded that PCA can effectively up-regulate the proliferation of hADSCs.     

RNA沉默抑制子p19调控细胞周期相关蛋白表达

番茄丛矮病毒的P19蛋白不仅是一个重要的病毒致病因子,而且还可作为RNA干扰(RNAi)的抑制子．这种作用是通过限制细胞内的小RNA,比如小干扰RNA(siRNAs)和微RNA(miRNAs)来实现．但是目前对P19蛋白在哺乳动物细胞上的作用还未见报道．构建了一株p19稳定表达的293细胞系,即293-p19．流式细胞仪分析发现在293细胞中过量表达P19蛋白可显著引发细胞周期的G2/M阻滞．细胞增殖实验显示,293-p19细胞的DNA复制及细胞生长均受到显著的抑制． 此外,研究还发现p19可使人胚肾293细胞内的细胞周期调控子的表达谱发生改变． 其中包括上调cyclin A1,CDK2,CDK4,CDK6,p18,cyclin D2,p19INK4d和E2F1,及下调p15,cyclin A,cyclin B1和cyclin E1的表达．上述研究结果提示,p19有可能靶向多个G2/M调控蛋白从而引发细胞的G2/M阻滞．     

氯化锂抑制A549细胞增殖及其对Polo-like激酶1转录活性的影响

利用糖原合成酶激酶3的抑制剂氯化锂作用于A549细胞,观察细胞形态与增殖的改变及其对Polo－like激酶1转录活性的影响.采用细胞计数检测细胞增殖,流式细胞术分析细胞周期变化;Western印迹检测磷酸化GSK3以及细胞周期相关蛋白p53、cyclin B1和Plk1的表达变化;RT-PCR检测Plk1 mRNA的表达;荧光素酶报告基因分析氯化锂对Plk1启动子活性的影响.结果显示,5 mmol/L氯化锂作用48 h后,A549细胞即发生明显的形态学改变,细胞增殖减慢并发生G2/M期阻滞;Plk1 mRNA和蛋白表达均升高,p53蛋白表达增强,而cyclin B1的蛋白表达无明显变化.氯化锂作用24 h后,可见pGL2-Plk1转染组中荧光素酶活性增高（与对照质粒相比,P<0.05）,48 h后更明显.以上结果表明, 氯化锂减慢A549细胞增殖,导致G2/M期阻滞,并能增强Plk1的启动子活性,促进Plk1的表达.     

RNA干扰Ｃyclin D1基因表达对瘢痕疙瘩成纤维细胞增殖和G1期调控的影响

为研究siRNA干扰瘢痕疙瘩成纤维细胞cyclin D1基因表达,对瘢痕疙瘩成纤维细胞的增殖、细胞周期和G1期调控的影响,构建了靶向cyclin D1的siRNA表达质粒.利用LipofecmmineTM2000转染体外培养的瘢痕疙瘩成纤维细胞,应用荧光定量PCR、RT-PCR检测cyclin D1 mRNA的干扰效果,应用MTT法、流式细胞仪检测细胞增殖和细胞周期的变化,应用免疫组织化学染色检测成纤维细胞中cyclin D1、CDK4、P16、pRb蛋白表达的影响.主要结果如F:a.靶向cyclin D1的特异性siRNA序列可以高效地抑制成纤维细胞cyclin D1基因表达,对照组与实验组在mRNA水平其表达抑制率分别为63.68%和92.83%(P<0.01);b.可以显著抑制瘢痕疙瘩成纤维细胞的增殖,改变细胞周期分布,G0/G1期细胞比例显著高于各对照组(P<0.05),细胞分裂被阻滞;c.免疫组化染色发现,转染72 h后,过表达的cyclin D1、CDK4和pRb蛋白,在瘢痕疙瘩成纤维细胞中均出现了不同程度的表达下调,而低表达的P16则呈上调表现.由上述结果可见,构建的靶向cyclin D1的RNAi表达质粒,可有效地抑制瘢痕疙瘩成纤维细胞cyclin D1基因表达,通过改变Gl期相关周期蛋白的水平,影响G1/S期的进程,显著地抑制成纤维细胞的增殖.     

Evidence that receptor activator of nuclear factor (NF)-kappaB ligand can suppress cell proliferation and induce apoptosis through activation of a NF-kappaB-independent and TRAF6-dependent mechanism

The receptor activator of NF-kappaB ligand (RANKL), a recently identified member of the tumor necrosis factor (TNF) superfamily, has been shown to induce osteoclastogenesis and dendritic cell survival. Most members of the TNF superfamily suppress cell proliferation and induce apoptosis, but whether RANKL does so is not known. We demonstrate that treatment of monocyte RAW 264.7 cells with RANKL induces dose-dependent growth inhibition (IC50 = 10 ng/ml) as determined by dye uptake and [3H]thymidine incorporation methods. Suppression of RANKL-induced NF-kappaB activation by dominant-negative IkappaBalpha or by the NEMO-peptide had no effect on RANKL-induced cell growth inhibition. Inhibition of RANKL-induced JNK activation, however, abolished the RANKL-induced apoptosis. Suppression of interaction of RANK with TRAF6 by TRAF6-binding peptide abrogated the anti-proliferative effects of RANKL, suggesting the critical role of TRAF6. Flow cytometric analysis of cells treated with RANKL showed accumulation of cells in G0/G1 phase of the cell cycle, and this accumulation correlated with a decline in the levels of cyclin D1, cyclin D3, and cyclin E and an increase in cyclin-dependent kinase inhibitor p27 (Kip). Flow cytometric analysis showed the presence of annexin V-positive cells in cultures treated with RANKL. RANKL-induced apoptosis was further confirmed using calcein AM/ethidium homodimer-1 dye and cleavage of poly(ADP-ribose) polymerase (PARP), procaspase 3, and procaspase 9; benzyloxycarbonyl-VAD, the pancaspase inhibitor, suppressed the PARP cleavage. Thus, overall, our studies indicate that RANKL can inhibit cell proliferation and induce apoptosis through a TRAF-6-dependent but NF-kappaB-independent mechanism.     

MicroRNA-195 Inhibits the Proliferation of Human Glioma Cells by Directly Targeting Cyclin D1 and Cyclin E1

Glioma proliferation is a multistep process during which a sequence of genetic and epigenetic alterations randomly occur to affect the genes controlling cell proliferation, cell death and genetic stability. microRNAs are emerging as important epigenetic modulators of multiple target genes, leading to abnormal cellular signaling involving cellular proliferation in cancers.In the present study, we found that expression of miR-195 was markedly downregulated in glioma cell lines and human primary glioma tissues, compared to normal human astrocytes and matched non-tumor associated tissues. Upregulation of miR-195 dramatically reduced the proliferation of glioma cells. Flow cytometry analysis showed that ectopic expression of miR-195 significantly decreased the percentage of S phase cells and increased the percentage of G1/G0 phase cells. Overexpression of miR-195 dramatically reduced the anchorage-independent growth ability of glioma cells. Furthermore, overexpression of miR-195 downregulated the levels of phosphorylated retinoblastoma (pRb) and proliferating cell nuclear antigen (PCNA) in glioma cells. Conversely, inhibition of miR-195 promoted cell proliferation, increased the percentage of S phase cells, reduced the percentage of G1/G0 phase cells, enhanced anchorage-independent growth ability, upregulated the phosphorylation of pRb and PCNA in glioma cells. Moreover, we show that miR-195 inhibited glioma cell proliferation by downregulating expression of cyclin D1 and cyclin E1, via directly targeting the 3′-untranslated regions (3′-UTR) of cyclin D1 and cyclin E1 mRNA. Taken together, our results suggest that miR-195 plays an important role to inhibit the proliferation of glioma cells, and present a novel mechanism for direct miRNA-mediated suppression of cyclin D1 and cyclin E1 in glioma.     

NGX6基因对人结肠癌细胞HT-29细胞周期的影响

NGX6基因是新克隆的候选抑瘤基因,研究表明NGX6重表达可抑制结肠癌细胞的增殖.为进一步研究NGX6对细胞周期的影响,采用流式细胞仪检测NGX6重表达对结肠癌细胞HT-29细胞周期的影响,发现NGX6重表达可增加HT-29细胞在G0/G1期的分布比例,减少了S,G2,M期细胞数.利用蛋白质印迹和流式细胞术分析NGX6转染前后HT-29细胞周期素(cyclins)和细胞周期素依赖性蛋白激酶抑制物(cyclin-dependentkinaseinhibitor,CKI)的表达变化,发现NGX6可下调HT-29细胞中cyclinE、cyclinD1的表达及上调p27的表达,对cyclinA和cyclinB的表达无明显影响,p16在三组结肠癌细胞中均无表达.研究结果表明,NGX6在HT-29细胞中通过下调cyclinE、cyclinD1和上调p27的表达,阻滞细胞周期于G0/G1期,从而发挥其在结肠癌中的抑瘤作用.     

A polyphenol mixture from cinnamon targets p38 MAP kinase-regulated signaling pathways to produce G2/M arrest

We recently demonstrated that treatment of three leukemic cell lines with an aqueous extract of cinnamon (CE) for 24 h produced dose-dependent arrests in the G2/M phase of the cell cycle. To accomplish the goal of understanding underlying mechanisms, we selected the cell line most responsive to the CE treatment to study the effects of the extract on signaling molecules regulating cell cycle progression. Cell cycle analyses were conducted on treated versus nontreated cells from 0-6 h. The percentages of cells in G2/M in CE-treated cells increased significantly from 11.0+/-1.0 to 23.6+/-1.4 after 6 h, while the percentage for nontreated cells remained unchanged (12.3+/-0.8). Multiparametric flow cytometric analyses were used to associate activation of p38 mitogen-activated protein kinase (MAPK) with cells arrested in G2/M, the size of these cells, and the presence or absence of cyclin B1. After 4 h, there was a 26% increase in the activated phosphorylated form of p38 MAPK in CE-treated cells compared with the nontreated control cells, with larger cells showing the greater increases. Although the proportion of CE-treated cells in G2/M was higher than controls, this population was shown to be less positive for cyclin B1 than the control G2/M population. Our results demonstrate that CE significantly modulated two signaling proteins, p38 MAPK and cyclin B, that regulate progression through G2/M. Overall, the data provide evidence that CE affects proliferation in a leukemic cell line by disrupting critical phosphorylating/dephosphorylating signaling events that propel cells through the G2/M phase.