破壁灵芝孢子粉诱导MCF-7细胞凋亡的机理研究

目的：研究破壁灵芝孢子粉对人乳腺癌细胞系MCF-7的诱导凋亡作用。方法：在体外设定不同浓度的孢子粉处理MCF-7细胞系的实验组,细胞培养24h后,用MTT法测定其细胞活力;碘化丙啶（vI）染色后流式细胞仪检测其凋亡情况;罗丹明123（Rodamine123）标记后于酶标仪530nIn处测定其荧光强度值以检测线粒体膜电位情况。结果：与对照组相比,随孢子粉浓度的上升,MCF-7细胞活力和增殖呈剂量依赖型的下降;流式细胞仪检测PI染色显示,各处理组的MCF-7细胞凋亡率随作用浓度的上升而增强,最高浓度组尤为明显;在高浓度组,罗丹明123荧光强度明显降低。这些结果表明孢子粉能抑制MCF-7细胞的活力扣增殖;诱导其凋亡;罗丹明荧光强度的减少,说明MCF-7线粒体膜电位有倒塌扣去极化的情况发生,提示MCF-7细胞的凋亡与线粒体有关。结论：破壁灵芝孢子粉可明显促进MCF-7细胞的凋亡。     

色胺酮对乳腺癌MCF-7细胞凋亡的诱导作用

目的:探讨色胺酮(Tryptanthrin,Try)对人乳腺癌MCF-7细胞增殖和凋亡的影响。方法:利用MTT方法检测Try(1.56-100μmol/L)对细胞增殖的影响;透射电镜观察细胞的形态学改变;流式细胞术检测细胞周期、凋亡情况及线粒体跨膜电位等指标。结果:MTT结果显示,Try在12.5-100μmol/L浓度范围内能明显抑制MCF-7细胞的增殖,并具有时间和浓度依赖性;透射电镜下可见Try作用48h后,MCF-7细胞有典型的凋亡样改变。Annexin V-FITC与PI双染,流式细胞仪检测结果显示:50、100μmol/LTry作用后,细胞的凋亡情况明显,与对照组相比差异显著;且影响了MCF-7的细胞周期分布,将细胞阻滞于G1期,抑制其DNA的合成;并导致细胞线粒体跨膜电位下降。结论:色胺酮能明显抑制MCF-7细胞增殖并具有诱导细胞发生凋亡的作用。     

下调CENP-E对乳腺癌MCF-7细胞的影响

目的:探讨有丝分裂检查点蛋白着丝粒蛋白-E(CENP-E)基因在肿瘤发生发展中的作用。方法:利用shRNA下调CENP-E基因的表达,分别用巢式PCR和Western blot检测CENP-E mRNA和蛋白的表达;MTT检测CENP-E下调后MCF-7细胞的增殖变化;流式细胞术检测CENP-E下调后对MCF-7细胞凋亡的影响;Transwell试验检测MCF-7细胞的迁移和侵袭能力变化;间接免疫荧光检测细胞内CENP-E蛋白和有丝分裂情况。结果:shRNA能有效抑制CENP-E mRNA和蛋白的表达。MTT结果显示CENP-E下调后MCF-7细胞的增殖能力减弱(P<0.05);流式细胞术显示下调CENP-E后能促进MCF-7细胞的凋亡;间接荧光结果显示CENP-E干扰后MCF-7细胞内CENP-E蛋白减少并伴有核分裂异常;Transwell试验显示CENP-E干扰组细胞的迁移和侵袭能力增强(P<0.05)。结论:下调部分CENP-E的表达能抑制MCF-7细胞的增殖,促进MCF-7细胞的凋亡,增强MCF-7细胞的迁移和侵袭能力。     

靶向微管抗肿瘤药物研究进展

微管由微管蛋白组成,在细胞分裂、细胞内物质运输、信号传递、维持细胞形态等过程中起着重要作用.一些干扰微管功能的化合物可使细胞停滞在有丝分裂期而抑制细胞增殖.相对于正常细胞,肿瘤细胞有丝分裂异常频繁,以微管作为抗肿瘤的靶点已成为研究热点.作用于微管的微管蛋白抑制剂通过抑制微管蛋白的聚合促进微管解聚或者抑制微管解聚促进微管蛋白聚合来破坏微管动态平衡、干扰肿瘤细胞纺锤体形成、阻断细胞分裂、抑制肿瘤增殖,现就微管蛋白抑制剂的研究进展作一综述.     

甲基莲心碱抗乳腺癌 MCF-7细胞的研究

目的:观察甲基莲心碱对乳腺癌细胞系MCF-7增殖和凋亡的影响,并探讨其诱导乳腺癌细胞系MCF-7凋亡的可能作用机制。方法:采用体外培养人乳腺癌细胞系MCF-7,CCK-8实验检测不同浓度甲基莲心碱对MCF-7细胞增殖抑制作用;乳酸脱氢酶(LDH)试剂盒(微板法)检测细胞上清液LDH含量;流式细胞术分析甲基莲心碱对MCF-7细胞周期及凋亡的影响;实时定量PCR(RT-PCR)检测线粒体凋亡相关基因Bax和Bcl-2的表达水平。结果:CCK-8、LDH结果显示甲基莲心碱以时间、浓度依耐性的方式抑制乳腺癌MCF-7细胞的增殖及促进细胞毒性的增加;流式细胞术结果表明不同甲基莲心碱作用下MCF-7的平均凋亡率分别为(15.44±0.52)、(18.81±2.24)、(24.26±2.84)、(36.90±3.15)、(59.27±5.86),且使其周期阻滞于G0/G1期;RT-PCR检测结果证明甲基莲心碱可上调乳腺癌细胞中促凋亡基因Bax的表达,而下调抑制凋亡基因Bcl-2。结论:甲基莲心碱以时间和浓度依赖的方式抑制乳腺癌细胞增殖、细胞毒性增加,导致细胞周期于G0/G1阻滞并促进癌细胞凋亡。甲基莲心碱抗乳腺癌的可能作用机制是激活线粒体凋亡途径。     

磺化壳聚糖对MCF-7的体外抑制作用研究

目的:研究磺化壳聚糖(SCTS)对体外培养的人乳腺癌细胞的增殖抑制和凋亡的作用.方法:用不同浓度磺化壳聚糖对体外培养人乳腺癌细胞MCF-7进行干预,MTT法检测SCTS对MCF-7细胞增殖的抑制作用;显微荧光法、流式细胞术检测细胞凋亡.结果:磺化壳聚糖抑制MCF-7细胞增殖,且呈时间、剂量依赖性;镜下可见凋亡细胞的形态学改变、FCM显示G0/G1期细胞增加,而S期细胞减少.结论:磺化壳聚糖可有效抑制人乳腺癌细胞MCF-7增殖,促进细胞凋亡.     

虎眼万年青总皂苷诱导人乳腺癌MCF-7细胞凋亡机制研究

为探讨虎眼万年青总皂苷(OCA-TS)诱导人乳腺癌MCF-7细胞凋亡的分子机制,本研究采用溴化四氮唑蓝(MTT)法检测OCA-TS对MCF-7细胞增殖的抑制作用,并观察细胞凋亡形态、检测细胞膜电位及凋亡相关蛋白含量变化。实验表明,OCA-TS可显著抑制人乳腺癌MCF-7细胞的增殖(IC_(50)为93.17μg/mL),电镜下细胞呈现典型的凋亡形态;流式细胞仪检测结果显示不同浓度的OCA-TS作用MCF-7细胞48 h后,细胞内线粒体膜电位、Ca~(2+)浓度和Cyt-C的表达水平均无显著变化;细胞内Caspase-8和Caspase-3的活性显著升高,而Caspase-12的活性均未见显著改变,Western blot检测细胞内Fas、FasL和FADD蛋白表达水平显著升高。综上说明OCA-TS诱导MCF-7细胞凋亡的作用可能是通过启动死亡受体途径而不是通过线粒体途径和内质网途径实现的。     

Surfactin对人乳腺癌MCF-7细胞增殖、凋亡及细胞骨架的影响

以体外培养的人乳腺癌细胞株MCF-7为研究对象,探讨surfactin对肿瘤细胞增殖、凋亡及细胞骨架的影响。MTT实验表明,surfactin能抑制MCF-7的增殖,并且呈现出浓度和时间的依赖关系,作用48h时的IC50是27.3μmol/L。AO/EB荧光染色法及流式细胞术检测发现,surfactin可诱导MCF-7发生典型的凋亡形态学改变和G2/M期阻滞。免疫荧光和免疫印迹结果表明,surfactin显著抑制了细胞内vimentin的表达,诱导了α-tubulin的解聚和重排,使细胞的骨架系统发生了剧烈的变化。可见,surfactin具有抑制MCF-7细胞增殖,诱导细胞凋亡的作用,其机制可能与细胞骨架蛋白的表达水平有关。     

桑葚花色苷提取物对乳腺癌细胞凋亡及线粒体膜电位的影响

目的:观察桑葚花色苷提取物对人乳腺癌细胞株MDA-MB-453、MDA-MB-231和MCF-7细胞凋亡及线粒体膜电位的影响.方法:利用超声辅助乙醇萃取法提取桑葚花色苷,pH示差法测定提取物花色苷总含量,以50、100和150 mg/mL桑葚花色苷提取物作用三种乳腺癌细胞MDA-MB-231、MDA-MB-453和MCF-7 24h,采用Annexin V/PI双染流式细胞分析法检测细胞凋亡水平变化,JC-1探针染色激光共聚焦扫描显微镜观察MDA-MB-453细胞线粒体膜电位水平变化.结果:凋亡分析结果表明,桑葚花色苷提取物作用后三种乳腺癌细胞凋亡率均升高,显示出促凋亡效应,且具有剂量-效应关系,100和150 mg/mL组凋亡率显著升高(P＜0.05).激光共聚焦扫描显微镜检测结果显示,桑葚花色苷提取物作用24h,可使MDA-MB-453细胞线粒体膜电位显著下降,表现为红色/绿色荧光的比值显著降低(P＜0.05).结论:桑葚花色苷提取物可显著降低乳腺癌细胞线粒体膜电位,并促发细胞凋亡.     

脱氧核酶抑制Akt1基因对MCF-7乳腺癌细胞生长的影响

目的应用脱氧核酶抑制Akt1的表达,观察MCF-7乳腺癌细胞生长及凋亡情况。方法采用噻唑蓝比色法（MTT）检测脱氧核酶抑制MCF-7乳腺癌细胞增殖作用;DAPI染色法分析细胞凋亡形态学的变化;流式细胞术检测脱氧核酶对MCF-7乳腺癌细胞凋亡的影响;运用蛋白免疫印迹检测分析Akt1、pro—caspase-3、pro-caspase-9的变化。结果Aktl脱氧核酶对MCF-7乳腺癌细胞在体外的生长具有抑制作用;DRz1组的细胞早期凋亡率显著高于未处理组;荧光显微镜下可见典型的凋亡形态学变化;脱氧核酶作用后,免疫印迹检测Aktl蛋白表达降低,pro—caspase-3、9均被活化。结论AktlDRzl能有效下调MCF-7乳腺癌细胞Akt1的蛋白表达水平,抑制MCF-7细胞的生长,且凋亡途径可能依赖于caspase-3、9的相关的线粒体凋亡途径。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.     

（鱼句）亚科花（鱼骨）型鱼类骨骼系统的比较

对我国花型Hemibarbuspattern鱼类作了骨骼系统比较,结果表明,此类型鱼类脑颅较长,副蝶骨平直或稍弯曲,眶蝶骨腹纵嵴发达(铜鱼Coreius septentrionalis例外),下颞窝和咽突中等大,基枕骨后突发达;脑颅中的上筛骨的后突、侧筛骨的外筛突,蝶耳骨的外突、上耳骨的后突、围眶骨和后颞窝等均有明显的差异;咽颅中的舌颌骨、尾舌骨、鳃盖骨和下咽齿的列数等又有显著的区别;附肢骨骼中的腰带骨、脊椎骨中的复合神经骨和第4椎骨腹侧的悬器等也有不同之处。据此,这些差异和区别可作为属间或种间的分类依据。