A quantitative colorimetric method to evaluate the functional state of human polymorphonuclear leukocytes

Summary The colorimetric assay previously described by Mosmann [11] for the measurement of cell viability and proliferation has been modified for the assessment of the functional state of human polymorphnuclear cells (PMNs). The ability of PMNs to reduce the tetrazolium salt MTT to formazan reflects directly the degree of stimulation induced by various agents. The underlying mechanism of MTT-reduction to formazan seems to be similar to that of nitroblue tetrazolium (NBT)-reduction. In contrast to the NBT-reduction assay, the formazan produced from MTT can easily be measured by an ELISA reader. Parallel experiments revealed a qualitative correlation between the concentration of formazan produced from MTT and the concentration of cytochrome C reduced by PMNs. Although oxidative burst may not be the actual lytic mechanism in cellular cytotoxicity of PMN, we also observed an association between MTT-reduction capacity and the cytotoxic activity of PMNs from normal donors in antibody dependent cellular cytotoxicity. Our results indicate that the MTT-reduction assay can be employed to estimate the functional state of polymorphnuclear granulocytes.Supported in part by grant no. CA33484 from the NIH     

两种细胞增殖分析方法的比较性研究

目的比较MTT法和EdU标记法两种常用测定细胞增殖的方法的优劣。方法以化疗药物顺铂浓度梯度处理前列腺癌细胞株PC-3,分别采用MTT法和EdU标记技术进行细胞增殖变化测定。结果 MTT组顺铂浓度增至5μg/mL时细胞活力和增殖明显受抑(P<0.05);EdU掺入组顺铂浓度增至2μg/mL时增殖细胞阳性率和胞内荧光强度均显著下降(P<0.05)。结论 MTT法简单、快速、经济,结果与活细胞数有关,间接反映细胞的增殖状态;EdU标记技术灵敏、客观,特异性标记分裂期细胞,直接反映细胞的增殖。     

奥曲肽对人子宫内膜癌HEC-1-B细胞增殖及其血管内皮生长因子表达的影响

目的探讨奥曲肽对人子宫内膜癌细胞增殖及其血管内皮生长因子（VEGF）表达的影响。方法加入不同浓度的奥曲肽对HEC-1-B细胞进行培养。细胞增殖用MTT法检测，细胞中VEGF的表达采用RT-PCR技术及酶联免疫吸附试验（ELISA）检测。结果加入奥曲肽培养后，HEC-1-B细胞的增殖受抑制．而且其VEGFmRNA指数降低，VEGF蛋白表达减少。结论奥曲肽能抑制人子宫内膜癌细胞增殖及VEGF的分泌。     

Inhibitory effect of endostatin expressed by human liver carcinoma SMMC7721 on endothelial cell proliferation in vitro

AIM: To construct a stable transfectant of human liver carcinoma cell line SMMC7721 that could secret human endostatin and to explore the effect of human endostatin expressed by the transfectant on endothelial cell proliferation. METHODS: Recombinant retroviral plasmid pLncx-Endo containing the cDNA for human endostatin gene together with rat albumin signal peptide was engineered and transferred into SMMC7721 cell by lipofectamine. After selection with G418, endostatin-transfected SMMC7721 cells were chosen and expanded. Immunohistochemical staining and Western blot were used to detect the expression of human endostatin in transfected SMMC7721 cells and its medium. The conditioned medium of endostatin-transfected and control SMMC7721 cells were collected to cultivate with human umbilical vein endothelial cells for 72 hours. The inhibitory effect of endostatin, expressed by transfected SMMC7721 cells, on endothelial proliferation in vitro was observed by using MTT assay. RESULTS: A 550 bp specific fragment of endostatin gene was detected from the PCR product of endostatin-transfected SMMC7721 cells. Immunohistochemistry and Western blot analysis confirmed the expression and secretion of foreign human endostatin protein by endostatin-transfected SMMC7721 cells. In vitro endothelial proliferation assay showed that 72 hours after cultivation with human umbilical vein endothelial cells, the optical density (OD) in group using the medium from endostatin-transfected SMMC7721 cells was 0.51 +/- 0.06, lower than that from RPMI 1640 group (0.98 +/- 0.09) or that from control plasmid pLncx-transfected SMMC7721 cells (0.88 +/- 0.11). The inhibitory rate for medium from endostatin-transfected SMMC7721 cells was 48%, significantly higher than that from empty plasmid pLncx-transfected SMMC7721 cells (10.2%, P<0.01). CONCLUSION: Human endostatin can be stably expressed by SMMC7721 cell transferred with human endostatin gene and its product can significantly inhibit the proliferation of human umbilical vein endothelial cell in vitro.     

Mitotic cell death in BEL-7402 cells induced by enediyne antibiotic lidamycin is associated with centrosome overduplication

AIM: Mitotic cell death has been focused on in tumor therapy.However, the precise mechanisms underlying it remain unclear. We have reported previously that enediyne antibiotic lidamycin induces mitotic cell death at low concentrations in human epithelial tumor cells. The aim of this study was to investigate the possible link between centrosome dynamics and lidamycin-induced mitotic cell death in human hepatoma BEL-7402 cells.METHODS: Growth curve was established by Ml-l assay.Cell multinucleation was detected by staining with Hoechst 33342. Flow cytometry was used to analyze cell cycle.Aberrant centrosomes were detected by indirect immunofluorescence. Western blot and senescenceassociated β-galactosidase (SA-β-gal) staining were used to analyze protein expression and senescence-like phenotype,respectively.RESULTS: Exposure of BEL-7402 cells to a low concentration of lidamycin resulted in an increase in cells containing multiple centrosomes in association with the appearance of mitotic cell death and activation of SA-β-gal in some cells, accompanied by the changes of protein expression for the regulation of proliferation and apoptosis. The mitochondrial signaling pathway, one of the major apoptotic pathways, was not activated during mitotic cell death. The aberrant centrosomes contributed to the multipolar mitotic spindles formation, which might lead to an unbalanced division of chromosomes and mitotic cell death characterized by the manifestation of multi- or micronucleated giant cells.Cell cycle analysis revealed that the lidamycin treatment provoked the retardation at G2/M phase, which might be involved in the centrosome overduplication.CONCLUSION: Mitotic cell death and senescence can be induced by treatment of BEL-7402 cells with a low concentration of lidamycin. Centrosome dysregulation may play a critical role in mitotic failure and ultimate cell death following exposure to intermediate dose of lidamycin.     

Mitotic cell death in BEL-7402 cells induced by enediyne antibiotic lidamycin is associated with centrosome overduplication

AIM:Mitotic cell death has been focused on in tumor therapy.However,the precise mechanisms underlying it remainunclear.We have reported previously that enediyneantibiotic lidamycin induces mitotic cell death at lowconcentrations in human epithelial tumor cells.The aim ofthis study was to investigate the possible link betweencentrosome dynamics and lidamycin-induced mitotic celldeath in human hepatorna BEL-7402 cells.METHODS:Growth curve was established by MTT assay.Cell multinucleation was detected by staining with Hoechst33342.Flow cytometry was used to analyze cell cycle.Aberrant centrosomes were detected by indirectimmunofluorescence.Western blot and senescence-associated β-galactosidase (SA-β-gal) staining were usedto analyze protein expression and senescence-like phenotype,respectively.RESULTS:Exposure of BEL-7402 cells to a low concentrationof lidamycin resulted in an increase in cells containing multiplecentrosomes in association with the appearance ofmitotic cell death and activation of SA-β-gal in somecells,accompanied by the changes of protein expressionfor the regulation of proliferation and apoptosis.Themitochondrial signaling pathway,one of the major apoptoticpathways,was not activated during mitotic cell death.Theaberrant centrosomes contributed to the multipolar mitoticspindles formation,which might lead to an unbalanceddivision of chromosomes and mitotic cell death characterizedby the manifestation of multi- or micronucleated giant cells.Cell cycle analysis revealed that the lidamycin treatmentprovoked the retardation at G2/M phase,which might beinvolved in the centrosome overduplication.CONCLUSION:Mitotic cell death and senescence canbe induced by treatment of BEL-7402 cells with a lowconcentration of lidamycin.Centrosome dysregulation mayplay a critical role in mitotic failure and ultimate cell deathfollowing exposure to intermediate dose of lidamycin.     

蛴螬提取物对人乳腺癌MCF-7细胞增殖的影响及其机制探讨

目的 观察蛴螬提取物对人乳腺癌MCF-7细胞增殖的影响及其机制。方法 采用MTT法检测蛴螬提取物处理过的人乳腺癌MCF-7细胞的生长抑制率，用免疫组化SP法检测用药前后增殖细胞核抗原（PCNA）、Ki-67、细胞周期蛋白D1（CyclinD1）的表达改变，用流式细胞仪检测细胞周期的变化。结果 用蛴螬提取物处理后的MCF-7细胞生长抑制率明显高于对照组，这种抑制作用呈浓度和时间依赖性；MCF-7细胞经蛴螬提取物处理后Ki-67、PCNA、CyclinD1表达均下降，且随着蛴螬提取物作用时间的延长，S期细胞比例明显升高。结论 蛴螬提取物在体外对人乳腺癌MCF-7细胞株有显著的增殖抑制作用，其机制可能与下调CyclinD1、Ki-67、PCNA的表达有关。     

熊果酸对人胃癌细胞株MGC-803的抑制作用及其机制

目的观察熊果酸（UA）对胃癌细胞株MGC-803的抑制增殖作用。方法培养胃癌细胞株MGC-803，以MTT比色法及生长曲线测定UA对MGC-803抑制增殖的作用。免疫印记法测定p-ERK1/2、CyclinD1、p21^waf/tip。表达。结果MTT实验及生长曲线均显示UA明显抑制MGC-803细胞增殖，免疫印记法显示UA抑制pERK1/2、CyclinD1表达，同时上调p21^waf/vip。表达。结论熊果酸可以抑制MGC-803增殖，机制与影响p-ERK1／2及下游CyclinD1、p21^waf/cipl表达有关。     

槐耳对人胃癌细胞MGC803增殖和凋亡的影响

[目的]观察中药槐耳对胃癌细胞株MGC803增殖和凋亡的影响.[方法]以不同浓度的槐耳（4、8、16、32、64 mg/ml）分别作用于体外培养的人胃癌细胞MGC803,通过MTT法、划痕实验等检测槐耳对MGC803细胞增殖和迁移的作用,倒置显微镜下观察细胞的形态变化,流式细胞仪检测细胞凋亡情况.[结果]MTT实验显示槐耳可抑制MGC803细胞的生长,呈时间及浓度依赖性;显微镜下可观察到细胞肿胀、破裂、呈坏死状;划痕实验显示,4、8 mg/ml槐耳分别作用MGC803细胞,划痕愈合明显慢于对照组,呈剂量依赖关系;流式细胞仪可检测到MGC803细胞凋亡率明显增加,呈时间及浓度依赖性.[结论]槐耳可抑制人胃癌MGC803细胞的迁移,且能通过诱导细胞凋亡的方式有效地抑制人胃癌细胞MGC803的生长.     

体外研究腺苷酸活化蛋白激酶对食管鳞癌EC9706细胞增殖及凋亡的影响

目的通过体外研究观察腺苷酸活化蛋白激酶(AMPK)的激活剂AICAR对人食管癌EC9706细胞的增殖及凋亡影响。方法 AICAR以不同浓度作用于人食管癌EC9706细胞,通过光学显微镜观察不同时间后EC9706细胞的生长状态,并用MTT方法检测其吸光度值及细胞存活率的变化,流式细胞术检测其细胞凋亡率情况。结果随着AICAR浓度的增加,细胞的死亡数目明显增加。MTT法检测结果表明,AICAR能够抑制EC9706细胞增殖,并呈现出良好的浓度依赖性。流式细胞术检测结果显示,不同浓度的AICAR干预24 h后早期凋亡率、晚期凋亡率及总凋亡率均高于对照组,但仅有总凋亡率有统计学意义(P0.01)。结论 AMPK可以抑制人食管癌EC9706细胞的生长增殖,并可诱导EC9706细胞凋亡。     

Correlation between the effects of bombesin antagonists on cell proliferation and intracellular calcium concentration in Swiss 3T3 and HT-29 cell lines.

Bombesin (BN) acts as an autocrine mitogen in various human cancers. Several pseudononapeptide BN-(6-14) analogs with a reduced peptide bond between positions 13 and 14 have been shown to suppress the mitogenic activity of BN or gastrin-releasing peptide (GRP) when assessed by radioreceptor or proliferation assays and may have significant clinical applications. The search for potent and safe BN antagonists requires the evaluation of a large series of analogs in radioreceptor and proliferation assays. In this paper, we report that the ability of BN analogs to inhibit BN-induced calcium transients in Swiss 3T3 cells shows a high correlation with their inhibitory potency as evaluated by classical proliferation tests. The assay of calcium transients allows a rapid characterization of new BN analogs (in terms of minutes rather than days) and can be adapted as a labor and cost-effective screening step in the selection of potentially relevant BN antagonists for further characterization in cell proliferation systems. We also observed that results from the assay of calcium transients in Swiss 3T3 cells can be correlated with the results of the proliferative response in HT-29 cells, a cell line that does not seem to use the same early transmembrane ionic signal system. This result suggests that the calcium pathway is not mandatory for triggering cell division by the BN receptor.     

DPC4基因对人胰腺癌细胞JF305增殖的影响

目的研究肿瘤抑制基因DPC4(deleted in pancreatic carcinoma)对人胰腺癌细胞系JF305增殖能力的影响。方法将携带DPC4基因的真核表达载体转入JF305细胞内,经G418筛选获得DPC4稳定表达细胞株,免疫细胞化学和RT-PCR法检测转染前后细胞内DPC4的表达。用MTT法、细胞计数法和流式细胞仪测定细胞生长曲线、细胞周期、细胞贴壁率和细胞克隆形成率。比较转染前后细胞增殖能力的变化。结果未转染及转染空质粒的JF305细胞无DPC4的表达,转染pBK-CMV-DPC4的JF305细胞可检测到DPC4的表达,且其细胞增殖能力较前明显下降(P<0．001),细胞倍增时间显著延长(由11．8d延长至18d),细胞贴壁率和克隆形成率均明显下降(P<0．0001),G_1期细胞所占比例明显增加(P<0．0001),G_2／M期细胞所占比例明显下降(P<0．0001)。结论无DPC4表达的胰腺癌细胞株JF305可转基因获得DPC4稳定表达,DPC4转基因后可抑制其增殖能力,细胞G_1期延长,G_2／M期缩短。DPC4有望成为胰腺癌基因治疗新的候选基因。     

RNA干扰Akt对食管癌细胞株Eca109生物学特性的影响

目的:探讨RNA干扰沉默Akt对人食管鳞癌细胞体外增殖、迁移及血管生成拟态(VM)形成的影响.方法:应用倒置荧光显微镜观察Akt的干扰质粒转染食管癌细胞Eca109后绿色荧光蛋白的表达;采用Western blot方法检测Akt蛋白的表达;四甲基偶氮唑蓝(MTT)法检测转染前后细胞增殖能力的变化;Transwell方法...     

藤梨根提取物对大肠癌LoVo细胞增殖的抑制作用及诱导凋亡的影响

目的:研究藤梨根提取物(ethanol extract from radix of actinidia chinensis,EERAC)对人大肠癌LoVo细胞增殖和凋亡的影响.方法:提取藤梨根抗癌有效活性成分(EERAC),按浓度分为4处理组(10、40、160、320mg/L)和空白对照组(0mg/L).各实验组经作用24、48、72h后,进行一般形态学和AO/EB荧光染色观察;MMT法检测细胞增殖的抑制情况;免疫组织化学(immunohistochemistry,IHC)法测定LoVo细胞中凋亡相关基因Bcl-2、Bax、Caspase-3的蛋白表达变化.结果:与空白对照组比较,一般形态学显示EERAC处理组能使细胞密度减低,增殖变慢;细胞逐渐变大,细胞间接触变松,胞浆中颗粒增多,细胞脱壁现象和周围碎片增多;荧光染色观察可见处理组细胞呈橙红色荧光,细胞核出现碎片状或固缩状的凋亡特征学形态改变,凋亡现象与EERAC的浓度呈正相关性;MTT法检测显示,EERAC处理组对LoVo细胞的最佳作用时间为72h,最大抑制率为79.48%,具有浓度和时间的依赖性(P<0.01);IHC检测结果显示EERAC作用LoVo细胞24h后,Bcl-2表达明显减弱,Bax、Caspase-3表达水平明显增高,Bcl-2/Bax比值下降,差异具有统计学意义(P<0.05),其效应与浓度相关.结论:EERAC具有明显抑制LoVo细胞增殖的作用,其机制可能与降低Bcl-2表达,上调Bax、Caspase-3的表达水平,激活线粒体凋亡途径有关.     

γ-氨基丁酸对胰腺癌SW1990细胞生长及VEGF表达的影响

目的观察γ-氨基丁酸（GABA）对胰腺癌SW1990细胞生长及血管内皮生长因子（VEGF）表达的影响。方法采用MTT法和流式细胞术（FCM）检测GABA对胰腺癌SW1990细胞增殖、细胞凋亡和细胞周期的影响，放射免疫分析法检测cAMP含量，RT—PCR检测VEGF mRNA表达，Western blot检测VEGF蛋白含量。结果GABA促进胰腺癌SW1990细胞生长，抑制细胞凋亡，同时促进细胞内cAMP增加。随着GABA浓度增加（80～320μmol／L），VEGF mRNA及蛋白表达明显增加。结论GABA影响胰腺癌细胞增殖、凋亡和血管形成，可能参与调节肿瘤的生长与转移。     

P21对胃癌细胞MGC-803的增殖抑制及对POLD1基因表达的调控

目的:研究P21对POLD1基因的调控通路,以探索阻断癌细胞恶性增殖的机制.方法:实验主要分3组:阴性对照组(转染空载体pXJ41-neo的803-pXJ细胞)、空白对照组(胃癌细胞MGC-803)、实验组(转染P21重组真核表达质粒pXJ41-p21的803-p21细胞).MTT实验分析细胞增殖变化,流式细胞仪检测细胞凋亡水平,实时荧光定量PCR技术检测基因表达水平的变化,Westernblot分析蛋白表达差异.结果:MTT实验显示,与空白对照和阴性对照组相比,实验组细胞增殖受到明显抑制,凋亡率(%)增高(11.36±0.51vs7.39±0.17,7.69±0.47,F=85.338,均P<0.05).实验组P21mRNA表达水平显著提高(2.15±0.23vs1.05±0.11,1.00±0.00,F=59.054,均P<0.05),POLD1则显著下调(0.45±0.07vs1.09±0.13,1.00±0.00,F=49.907,均P<0.05);P21、P125蛋白表达变化与基因变化相一致.cyclinE、Rb1基因表达均上调,CDK2基因表达下调,c-myc基因表达则变化不大.结论:P21抑制了...     

α硫辛酸抑制血管内皮细胞增殖的实验研究

目的探讨α硫辛酸(LA)对血管内皮细胞增殖的影响。方法采用人脐静脉内皮细胞(HUVECs)培养模型,分析LA对HUVECs细胞活力(MTT测定)、细胞增殖(EdU掺入实验)、增殖相关基因表达(定量PCR分析)、细胞死亡[乳酸脱氢酶(LDH)渗漏实验、Hoechst33342细胞核染色]的影响。结果LA呈剂量依赖性、时间依赖性地抑制HUVECs活力。LA抑制HUVECs增殖。LA抑制与HUVECs增殖相关的C-Myc基因表达。LA不引起LDH渗漏,也不引起HUVECs核固缩。结论LA显著抑制血管内皮细胞增殖,但不引起细胞死亡,提示LA对血管异常增生的疾病如恶性肿瘤具有潜在治疗作用。     

氧化型高密度脂蛋白对内皮细胞的损伤作用

目的 探讨氧化高密度脂蛋白（ox-HDL）对人脐静脉内皮细胞（HUVECs）的损伤作用.方法 体外培养HUVECs与不同浓度（50～200 mg/L）ox-HDL共孵育,用普通光镜和荧光显微镜分别观察HUVECs细胞形态及核形态的变化,用噻唑兰（MTT）比色法检测细胞存活状况.结果 ox-HDL使内皮细胞数目减少,形态改变;Hoechst 33258染色后可见大量的细胞核浓缩呈高亮度蓝色荧光的凋亡细胞.MTT结果显示,细胞存活率下降,且呈剂量依赖性.结论 ox-HDL可导致内皮细胞受损,从而促进动脉粥样硬化的发生、发展.     

miR-451对食管癌EC9706细胞增殖、凋亡及侵袭能力的影响

目的:探讨miR-451对食管癌EC9706细胞增殖、凋亡及侵袭能力的影响.方法:化学合成miR-451mimics,脂质体包裹转染EC9706细胞为miR-451组,同时设立无关序列(Scramble-miR)对照组、脂质体对照组和空白对照组.转染后48h,荧光定量RT-PCR检测miR-451表达量的变化,Westernblot检测Bcl-2、AKT和磷酸化AKT蛋白表达水平,流式细胞仪检测细胞凋亡情况,Transwell侵袭实验检测细胞侵袭能力的改变;MTT法检测转染后l、2、3、4、5、6d各组细胞增殖率.结果:miR-451组的miR-451表达水平显著上调(P<0.01,F=69.26),为空白对照组的15.84倍;miR-451组细胞Bcl-2、AKT和磷酸化AKT蛋白表达均显著下调(P<0.05,F=5.83);miR-451组细胞凋亡率为12.07%±1.12%,与3个对照组比较显著升高(P<0.01,F=26.72);miR-451组平均侵袭细胞数为47.4±7.4,与3个对照组比较显著降低(P<0.01,F=34.55).miR-451组细胞的生长在转染后2d出现显著抑制(P<0.05,F=5.95),并且随时间的延长而日益显著.结论:上调miR-451表达可抑制食管癌EC9706细胞增殖和侵袭,促进细胞凋亡.     

Proliferating cell nuclear antigen (PCNA): a new marker to study human colonic cell proliferation.

Immunohistochemistry of the S phase related proliferating cell nuclear antigen (PCNA) was studied as an alternative to ex-vivo bromodeoxyuridine (BrdU) immunohistochemistry for assessment of human colonic cell proliferation. From 16 subjects without colonic disease biopsy specimens were collected from five different sites along the colorectum and processed for BrdU and PCNA immunohistochemistry. The mean proliferation index of PCNA was significantly higher at 133% of the value obtained with BrdU. There was, however, a good correlation between the results from both techniques (r = 0.6275; p < 0.05). Decrease in proliferation index along the colorectum was seen with both staining methods but was clearer with PCNA immunohistochemistry (caecum/ascending colon v rectum: 12.0 v 7.2; p < 0.004). The total number of crypt cells also decreased from proximal to distal (134 to 128; p < 0.06) but at no site correlated significantly with the proliferation index. It is concluded that in clinical cell kinetic studies staining for PCNA may serve as an attractive alternative to the BrdU incorporation assay.