从槐米中提取槲皮素的研究

目的 本文从槐米中提取分离槲皮素进行研究.方法 采用碱溶酸沉法提取,再进行酸水解得到槲皮素.结果 确定了碱溶解酸沉淀法提取槐米中槲皮素的最佳条件及槲皮素的结构鉴定.结论 用碱溶解酸沉淀法从槐米中提取槲皮素是很有意义的,可以较好的提取分离出较高纯度的槲皮素.     

伊达比星在MCF-7乳腺癌细胞系中对DNA及c-myc的作用

本文评价了伊达比星(idarubicin)对DNA合成、c-myc表达及MCF-7乳腺癌细胞生长的作用。进一步证明了在不存在DNA断裂和凋亡现象时乳腺癌细胞也能发生死亡。采用MTT四唑蓝染色试验来评价DNA生长抑制;采用碱洗脱方法来检测诱导DNA链断裂;对DNA合成的抑制是通过测量掺入DNA的标记胸腺嘧啶来确定的;由Northern印迹法来检测对致癌基因c-myc表达的调控;由碱解链、静电场凝胶电泳、末端标记和细胞形态学研究来评价诱导细胞凋亡。实验结果表明,伊达比星对MCF-7乳腺癌细胞有浓度依赖性的抑制生长作用,其IC50值约为0.01μmol·L-1。只有当…     

丁酸钠对乳腺癌细胞MCF-7生长的抑制作用

目的 初步研究丁酸钠对乳腺癌细胞MCF-7生长的抑制作用.方法 常规培养乳腺癌细胞MCF-7至对数生长期,观察用丁酸钠处理后细胞生长速度、倍增时间、克隆形成率、细胞周期分布和细胞凋亡的变化.结果 与MCF-7亲本细胞相比,用丁酸钠处理的MCF-7细胞:①生长速度减慢.倍增时间延长(MCF-7亲本细胞、2.5mmol/L、5mmol/L和10mmol/L丁酸钠处理的MCF-7细胞倍增时间分别为29.9h、62.3h、164.2h和301.0h,P<0.05);②克隆形成率显著降低(MCF-7亲本细胞和丁酸钠(5mmol/L)处理24h的MCF-7细胞平均克隆形成率分别为72%和16.7%,P<0.05);③出现明显的G1期阻滞,S期和G2/M期细胞比例显著减少(P<0.05);④凋亡细胞数量明显增加(P<0.05);⑤出现明显的DNA"梯子"样断裂变化.结论 初步揭示了丁酸钠可以逆转乳腺癌细胞MCF-7的恶性生物学行为,其该作用可能与诱导MCF-7细胞凋亡有关,为丁酸钠在乳腺癌治疗中应用的可能性提供了初步的理论和实验依据.     

路路通酸对乳腺癌MCF-7细胞和宫颈癌C-33A细胞增殖的影响

目的研究路路通酸(BTA)对乳腺癌MCF-7细胞及宫颈癌C-33A细胞增殖的影响。方法采用MTT法检测不同浓度BTA作用不同时间后对MCF-7细胞、C-33A细胞的增殖抑制作用;流式细胞仪检测BTA处理后细胞周期的变化。结果 BTA作用于乳腺癌MCF-7细胞24、48、72 h后的IC50分别为(37.62±1.72)、(27.32±0.99)、(19.19±0.90)μmol/L。BTA作用于宫颈癌C-33A细胞24、48、72 h后的IC50分别为(34.55±0.88)、(27.20±1.03)、(16.74±0.79)μmol/L,BTA对2种细胞增殖有明显抑制作用,且呈浓度时间依赖性(P<0.05),流式结果显示,BTA将MCF-7细胞阻滞在S期,并诱导其凋亡;BTA将C-33A细胞阻滞在G1-S期。结论BTA对乳腺癌MCF-7细胞和宫颈癌C-33A细胞具有较强的增殖抑制作用,其机制与细胞周期阻滞和诱导细胞凋亡有关。     

地塞米松预处理人乳腺癌MCF-7细胞对多西他赛抗肿瘤活性的影响

目的 探讨地塞米松预处理人乳腺癌MCF-7细胞后,对化疗药物多西他赛(艾素)抗肿瘤活性的影响.方法 以不同浓度(1×10-8～1×10-6 mol·L-1)的地塞米松预先作用于人乳腺癌MCF-7细胞后,再以艾素(5×10-6 mol·L-1)处理,在以上药物作用的相应时间段,通过流式细胞仪技术测定细胞凋亡,采用细胞计数观察细胞生长密度、形态.结果 地塞米松对MCF-7细胞增殖有抑制作用(P＜0.01),艾素能够明显抑制MCF-7细胞增殖,促进其凋亡(P＜0.01),地塞米松预处理后艾素干预MCF-7细胞的增殖抑制作用较单用艾素减弱(P＜0.01),且随地塞米松浓度的增加,其对化疗药艾素的凋亡抑制作用的影响增强.结论 地塞米松预处理对艾素诱导的人乳腺癌MCF-7细胞的凋亡具有明显的阻抑作用,抑制了多西他赛的抗肿瘤活性.     

顺铂加重乳腺癌MCF-7细胞DNA损伤促凋亡的研究

目的顺铂(DDP)为广谱抗癌药物,本研究探讨其对MCF-7乳腺癌细胞DNA损伤的作用,并研究其引起细胞凋亡的机制。方法采用DDP(0、2、4、6、8、10 mg·L~(-1))处理乳腺癌MCF-7细胞48 h,MTT法检测顺铂对细胞活性的抑制作用,并计算IC_(50);Western blot检测DNA断裂形成的标志分子γ-H2AX及直接感受DNA双链断裂(DSBs)的分子ATM、细胞凋亡信号分子cleaved caspase-3及凋亡相关的蛋白钙蛋白酶calpain的表达。结果 DDP呈浓度依赖性抑制细胞MCF-7活性,IC_(50)为7.57 mg·L~(-1);与对照组(未采用顺铂处理)相比,顺铂处理组MCF-7细胞内γ-H2AX、ATM、cleaved caspase-3、calpain的表达量增多。结论 DDP可抑制乳腺癌MCF-7细胞的活性,其机制与促进MCF-7细胞凋亡,诱导DNA双链断裂,上调促凋亡相关蛋白有关。     

天花粉对人乳腺癌MCF-7细胞凋亡及相关基因表达的影响

目的研究天花粉对人乳腺癌MCF-7细胞凋亡及相关基因表达的影响。方法取对数生长期人乳腺癌MCF-7细胞以30,60,90,120μg·m L^-1的天花粉蛋白处理,作为实验组,对照组用等量的0.9%Na Cl处理,继续培养24,48,72h。观察并比较各组细胞形态学及细胞核凋亡形态学变化,以噻唑蓝(MTT)比色法检测各组人乳腺癌MCF-7细胞增殖抑制情况,分光光度法检测天花粉蛋白对人乳腺癌MCF-7细胞胱天蛋白酶(caspase)-3和caspase-8表达的影响。结果实验组人乳腺癌MCF-7细胞呈现明显的细胞凋亡及核凋亡现象,且随天花粉蛋白质量浓度的增加,其细胞核凋亡现象越明显;干预24 h后,30,60,90,120μg·mL^-1实验组增殖抑制率分别为(1.61±0.94)%,(2.81±1.01)%,(7.05±1.03)%和(9.59±1.12)%;干预48 h后增殖抑制率分别为(2.13±1.01)%,(6.14±1.12)%,(9.05±1.09)%和(19.60±1.15)%;干预72 h后增殖抑制率分别为(3.28±1.07)%,(7.18±1.51)%,(18.39±1.81)%和(29.59±1.63)%。实验组人乳腺癌MCF-7细胞增殖抑制率随作用时间的延长及天花粉蛋白质量浓度的增大而逐渐升高(均P<0.01);90μg·m L^-1实验组24,48,72 h caspase-3分别为1.49±0.15,2.36±0.25,2.15±0.23;caspase-8分别为1.94±0.26,1.56±0.19,1.39±0.20。对照组人乳腺癌MCF-7细胞caspase-3及caspase-8随作用时间的延长无显著变化(均P>0.05),而90μg·mL^-1实验组caspase-3先升高后降低(P<0.05或P<0.01),以48 h时最高;caspase-8则逐渐降低(P<0.01);且各时间点90μg·m L^-1实验组caspase-3及caspase-8均显著高于对照组(均P<0.01)。结论天花粉蛋白可有效促进人乳腺癌MCF-7细胞凋亡,抑制其增殖,且增殖抑制作用呈时间-剂量依赖性,其作用机制可能与上调人乳腺癌MCF-7细胞caspase-3及caspase-8表达相关。     

组织蛋白酶B在SAHA诱导乳腺癌MCF-7细胞凋亡过程中的调控作用

目的阐明组织蛋白酶B(cathepsin B,Cat B)在SAHA诱导的乳腺癌雌激素受体阳性细胞系MCF-7细胞凋亡中的调控作用。方法采用MTT法检测SAHA对乳腺癌MCF-7细胞生长状况的影响;应用ELISA方法测定SAHA作用于MCF-7细胞后相关蛋白表达变化的情况;通过Bio Station~(IM)活细胞工作站实时收集各种处理因素对乳腺癌MCF-7细胞增殖干预的形态学影响;并通过自动细胞分析仪Muse Cell Analyzer分析SAHA对MCF-7细胞活力和细胞凋亡的影响。结果 SAHA能明显抑制乳腺癌MCF-7细胞的增殖,其最佳作用浓度为10μmol·L~(- 1),最佳作用时间为24 h。ELISA结果表明,SAHA能诱导乳腺癌MCF-7细胞中Cat B的表达。实时活细胞工作站成像实验从形态学上证明,Cat B抑制剂Cystatin C和SAHA联合应用可有效阻止SAHA对MCF-7细胞生长的抑制作用。细胞学实验结果表明,SAHA能使MCF-7细胞活力下降,细胞凋亡发生率明显增高;然而经过Cystatin C处理后的MCF-7细胞活力增加,细胞凋亡发生率下降。结论 Cat B在SAHA诱导乳腺癌雌激素受体阳性细胞MCF-7凋亡过程中具有重要的调控作用。     

人参皂甙Rg3对乳腺癌MCF-7线粒体凋亡途径的影响

目的探讨20(R)–人参皂甙Rg3(SPG-Rg3)对人乳腺癌MCF-7细胞的诱导凋亡作用及其可能机制。方法人乳腺癌细胞MCF-7细胞株分为空白对照组、实验对照组及SPG-Rg3多个浓度组。利用MTT法观察人参皂甙Rg3对MCF-7细胞生长的抑制作用,并计算出IC-50,进一步确定其有效浓度;流式细胞术检测人参皂甙Rg3作用后MCF-7细胞周期的变化;利用AnnexinV-EGFP/PI双染法,检测人参皂甙Rg3诱导MCF-7细胞凋亡情况;免疫细胞化学染色检测MCF-7细胞凋亡与Fas、FasL蛋白表达的关系。结果 SPG-Rg3作用48h的IC-50为244.54μg/mL。流式细胞仪检测Rg3使MCF-7的S期细胞比率明显增加(P<0.01),凋亡率明显增加(P<0.01)。免疫细胞化学显示Rg3能使MCF-7细胞胞浆内细胞色素C增加(P<0.01)。结论 SPG-Rg3能诱导乳腺癌MCF-7细胞凋亡,其机制可能与诱导线粒体释放细胞色素C有关。     

苦参碱对人乳腺癌MCF-7细胞的促凋亡作用及其对线粒体跨膜电位的影响分析

目的研究苦参碱对人乳腺癌(michigan cancer foundation-7,MCF-7)细胞的促凋亡作用及对线粒体跨膜电位的影响。方法体外培养人乳腺癌MCF-7细胞,观察组细胞中加入不同浓度的苦参碱溶液,对照组细胞中加入等量的培养液。MCF-7细胞的凋亡与细胞线粒体跨膜电位采用流式细胞仪检测,MCF-7细胞的抑制率采用MTT的方法检测。结果苦参碱处理24h后观察组的MCF-7细胞凋亡率明显高于对照组,差异有统计学意义(P<0.05),且随着浓度的升高而升高;苦参碱对于MGF-7细胞抑制率的结果显示,随着时间与浓度的增加苦参碱对于MGF-7细胞抑制率效应也随之增强,且差异有统计学意义(P<0.05);苦参碱处理24 h后的罗丹明染色阳性数低于对照组,差异有统计学意义(P<0.05),表明线粒体跨膜电位与浓度呈负相关。结论苦参碱对人乳腺癌MCF-7细胞有促凋亡的作用,其促凋亡的作用可能是通过降低线粒体跨膜电位而使MMP的通道打开。     

结肠靶向定位滴丸克癌素的提取工艺研究

目的建立结肠靶向滴丸克癌素的提取工艺方法。方法采用碱溶酸沉法从槐米中提取芦丁,再进行酸水解得到槲皮素;采用传统乙醇回流法从姜黄中提取总姜黄素,以姜黄中的总姜黄素含量为指标,通过正交表分析确定最佳提取工艺。结果槲皮素的提取条件为:碱性pH8～9,酸性pH3～5条件下提取芦丁;得到精制芦丁加100倍量的2%硫酸酸水解90min。姜黄的最佳提取工艺为:85%乙醇回流提取3次,每次1h;得浸膏上硅胶柱收集氯仿洗脱部分得总姜黄素。结论该工艺可行,可为结肠靶向滴丸克癌素的生产提供参考。     

槲皮素通过靶向GAS5/Notch1信号通路促进乳腺癌细胞凋亡的研究

目的探讨槲皮素对乳腺癌细胞促凋亡作用的可能机制。方法用槲皮素处理乳腺癌MCF-7细胞后,采用MTT法检测细胞活力;平板克隆实验检测细胞增殖克隆能力;Annexin V-FITC/PI双染法检测细胞凋亡;同时,分别采用槲皮素(40、80、160μmol·L^-1)、GAS5小干扰RNA(siGAS5)、槲皮素(80μmol·L^-1)协同siGAS5处理细胞后,qRT-PCR法和Western blot法检测GAS5、Notch1、Jagged1、Hes1、Bcl-2、Bax、Caspase-3的表达。结果槲皮素(40、80、160μmol·L^-1)处理MCF-7细胞后,发现40μmol·L^-1槲皮素可明显抑制增殖,而80、160μmol·L^-1槲皮素不仅明显抑制增殖且诱导凋亡;槲皮素(40、80、160μmol·L^-1)可上调GAS5、Bax和Caspase-3的表达,下调Notch1、Jagged1、Hes1和Bcl-2的表达;细胞转染siGAS5后,与sncRNA组相比,GAS5、Bax和Caspase-3表达下调,Notch1、Jagged1、Hes1和Bcl-2表达上调;当siGAS5与槲皮素(80μmol·L^-1)共处理细胞后,与sncRNA加槲皮素对照组相比,GAS5、Bax和Caspase-3表达下调,Notch1、Jagged1、Hes1和Bcl-2上调。结论槲皮素通过靶向GAS5/Notch1信号通路促进乳腺癌细胞凋亡。     

Quercetin-mediated cell cycle arrest and apoptosis involving activation of a caspase cascade through the mitochondrial pathway in human breast cancer MCF-7 cells

Dietary polyphenols have been correlated with a reduced risk of developing cancer. Quercetin (a natural polyphenolic compound) induced apoptosis in many human cancer cell lines, including breast cancer MCF-7 cells. However, the involvement of possible signaling pathways and the roles of quercetin in apoptosis are still undefined. The purpose of this study was to investigate the effects of quercetin on the induction of the apoptotic pathway in human breast cancer MCF-7 cells. When MCF-7 cells were treated with quercetin for 24 and 48 h and at various doses (10–175 μM), cell viability decreased significantly in time- and dose-dependent manners. Exposure of MCF-7 cells to 10–175 μM quercetin resulted in an approximate 90.25% decrease in viable cells. To explicate the mechanism underlying the antiproliferative effect of quercetin, cell cycle distribution and apoptosis in MCF-7 cells was investigated after exposure to 150 μM quercetin for 6–48 h. Quercetin caused a remarkable increase in the number of S phase (14.56% to 61.35%) and sub-G1 phase cells (0.1% to 8.32%) in a dose- and time-dependent manner. Quercetin caused S phase arrest by decreasing the protein expression of CDK2, cyclins A and B while increasing the p53 and p57 proteins. Following incubation with quercetin for 48 h, MCF-7 cells showed apoptotic cell death by the decreased levels of Bcl-2 protein and ΔΨ _m and increased activations of caspase-6, -8 and -9. Moreover, quercetin increased the AIF protein released from mitochondria to nuclei and the GADD153 protein translocation from endoplasmic reticulum to the nuclei. These data suggested that quercetin may induce apoptosis by direct activation of the caspase cascade through the mitochondrial pathway in MCF-7 cells.     

金雀异黄素和槲皮素对人类乳腺癌细胞增殖和细胞周期的影响

目的探讨金雀异黄素(genistein,Gen)和槲皮素(quercetin,Que)对人类乳腺癌细胞株增殖的影响。方法采用噻唑蓝(MTT)比色法测定槲皮素对雌激素依赖性乳腺癌细胞MCF-7、T47D和非雌激素依赖性乳腺癌细胞MDA-MB231的细胞增殖作用,并以雌激素受体拮抗剂ICI182780为工具药来评价金雀异黄素、槲皮素发挥雌激素样作用与雌激素受体的关系,流式细胞术对MCF-7细胞的增殖情况进行分析。结果Gen和Que在一定剂量范围内能促进T47D和MCF-7细胞的增殖,而对雌激素受体阴性MDA-MB231细胞未见增殖作用,并将MCF-7细胞周期由G1期向S期推进,促进DNA合成,提高细胞分裂增殖指数,且Gen和Que促进MCF-7细胞增殖作用被雌激素受体拮抗剂所拮抗。结论金雀异黄素和槲皮素具有雌激素活性,此作用可能是通过雌激素受体(ER)介导的。     

Inhibition of serum deprivation-induced PC12 cell apoptosis by tanshinone II A.

AIM: To study the effect of tanshinone II A (Tan II A) on PC12 cell apoptosis induced by serum deprivation. METHODS: PC12 cell survival was measured by MTT assay. The DNA content and percentage of apoptosis were monitored by flow cytometry and DNA fragmentation was analyzed by agarose gel electrophoresis. RESULTS: Serum-free (12 h) medium induced apoptosis in PC12 cells. When the cells had been treated with Tan II A (0.1 and 1 micromol . L-1) for 12 h, the percentage of PC12 cell apoptosis was greatly decreased to 25.71 % and 4.89 % from 96.07 % in serum deprivation alone group, and DNA fragmentation was prevented. Tan II A (0.01 - 10 micromol . L-1) attenuated the cytotoxic effect of sodium cyanide (20 mmol . L-1), glutamate (0.5 mmol . L-1), and sodium nitroprusside (0.5 mmol . L-1). CONCLUSION: Tan II A prevented PC12 cells from apoptosis induced by serum-free medium.     

P53-mediated cell cycle arrest and apoptosis through a caspase-3- independent, but caspase-9-dependent pathway in oridonin-treated MCF-7 human breast cancer cells

Aim： To study the caspase-3-independent mechanisms in oridonin-induced MCF-7 human breast cancer cell apoptosis in vitro. Methods： The viability of oridonin- treated MCF-7 cells was measured by MTT （thiazole blue） assay. Apoptotic cells with condensed nuclei were visualized by phase contrast microscopy. Nucleosomal DNA fragmentation was assayed by agarose gel electrophoresis. The apoptotic ratio was determined by lactate dehydrogenase assay. Cell cycle alternation and mitochondrial membrane potential were measured by flow cytometric analysis. Bax, Bcl-2, caspase-3, caspase-9, heat shock protein （Hsp）90, p53, p-p53, p21, Poly （ADP-ribose） polymerase （PARP）, and the inhibitor of caspase-activated DNase （ICAD） protein expressions were detected by Western blot analysis. Results： Oridonin inhibited cell growth in a time- and dose-dependent manner. Cell cycle was altered through the upregulation of p53 and p21 protein expressions. Pancaspase inhibitor Z-VAD-fmk and calpain inhibitor II both decreased cell death ratio. Nucleosomal DNA fragmentation and the downregulation of △ψmit were detected in oridonin-induced MCF-7 cell apoptosis, which was involved in a postmitochondrial caspase-9-dependent pathway. Decreased Bcl-2 and Hsp90 expression levels and increased Bax and p21 expression levels were positively correlated with elevated levels of phosphorylated p53 phosphorylation. Moreover, PARP was partially cleaved by calpain rather than by capase-3. Condusion： DNA damage provoked alternations in the mitochondrial and caspase-9 pathways as well as p53-mediated cell cycle arrest, but was not related to caspase-3 activity in oridonin-induced MCF-7 cells.     

丁酸钠对乳腺癌细胞MCF-7生长抑制的影响

目的探讨丁酸钠对乳腺癌细胞MCF-7生长的抑制作用。方法将乳腺癌细胞MCF-7常规培养至对数生长期,采用浓度为0、2．5、5．0、10．0mmol／L的丁酸钠处理后,观察对MCF生长的抑制作用。结果浓度为2．5、5．0、10．0mmol／L的丁酸钠处理的MCF-7细胞生长速度明显慢于亲本细胞,随着浓度的增加呈减慢趋势,差异有统计学意义（P〈0．05）。浓度为5mmol／L的丁酸钠处理后的MCF-7细胞克隆形成率明显低于MCF亲本细胞,差异有统计学意义（P〈0．05）。丁酸钠处理的细胞G1明显高于亲本细胞,S期及G2／M期明显低于亲本细胞,凋亡细胞百分比明显高于亲本细胞,差异有统计学意义（P〈0．05）。结论丁酸钠可能是通过诱导MCF-7细胞凋亡而起到逆转其恶性生物学行为的作用。     

Pseudolaric acid B induces apoptosis, senescence, and mitotic arrest in human breast cancer MCF-7

Aim： The aim of the present study was to investigate the inhibitory effect of pseudolaric acid B （PAB） on human breast cancer MCF-7 cells. Methods： 3-（4,5- dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide analysis, morphological changes, acridine orange staining, and agarose gel electrophoresis were applied to detect apoptosis. The percentage of apoptotic and necrotic cells was calcu- lated by the lactate dehydrogenase activity-based cytotoxicity assay; senescence associated （SA）-~-galactosidase activity was detected to evaluate senescence; flow cytometric analysis of propidium iodide staining was carried out to investi- gate the distribution of cell cycle, and the protein expression was examined by Western blot analysis. Results： During apoptosis, the half maximal inhibitory concentration IC5o was 3.4 and 1.35 μmol/L at 36 and 48 h after PAB treatment, respectively. The MCF-7 cells exposed to PAB showed typical characteristics of apoptosis, including the morphological changes and DNA fragmentation. The MCF-7 cells treated with 4 lamol/L PAB for 36 h underwent apoptosis, but not necrosis. The apoptosis induced by PAB was independent of the death receptor pathway. The senescent cells became larger and flatter, and the SA-β-galactosi- dase staining was positive. PAB induced obvious mitotic arrest and it preceded apoptosis and senescence. The expressions of p21 and p53 was upregulated with PAB treatment, and cyclin B 1 was upregulated and transported from the cyto- plasm to nuclei, and sustained stable levels. Conclusion： PAB induced mitotic arrest in the MCF-7 cells and inhibited proliferation through apoptosis and senescence. The apoptosis was independent of the death receptor pathway.     

Antitumor activities of quercetin and quercetin-5′,8-disulfonate in human colon and breast cancer cell lines

This study is designed to compare the anticancer effects of quercetin and its water-soluble sulfated derivative, quercetin-5′,8-disulfonate (QS), in human colon cancer LoVo cells and breast cancer MCF-7 cells. It was found that both quercetin and QS can inhibit the growth of cancer cells in a dose-dependent manner, with the IC₅₀ values of 40.2 and 28.0 μM for LoVo cells and 30.8 and 19.9 μM for MCF-7 cells, respectively, suggesting QS was more effective against the cancer cells than quercetin. Moreover, flow cytometric assay revealed that quercetin and QS could mediate the cell-cycle arrest principally in the S phase after 24 h of treatment with the two tumor cells. It was also found that 69.6% of LoVo cells and 90.6% of MCF-7 cells entered the early phase of apoptosis when treated with 100 μM QS for 48 h. Furthermore, we firstly found the generation of ROS is a critical mediator in QS-induced cell growth inhibition. Taken together, the novel sulfated derivative of quercetin possesses strong antitumor activity via a ROS-dependent apoptosis pathway, and has the excellent potential to be developed into an antitumor precursor compound.