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1.
目的探讨香菇Latcripin-8蛋白对HepG-2肝癌细胞凋亡的诱导作用及其机制。方法运用倒置显微镜、透射电镜、吉姆萨染色法和流式细胞仪法对细胞凋亡进行检测。采用Western blot法检测JAK3、STAT3和P53等凋亡相关蛋白的表达水平。采用Caspase-8活性检测盒检测Caspase-8活性。结果 HepG-2细胞经Latcripin-8蛋白作用后,倒置显微镜、透射电镜和吉姆萨染色等检测显示在形态学上Latcripin-8蛋白结构域抑制HepG-2细胞生长,并伴有凋亡小体产生。流式细胞仪检测显示该蛋白诱导HepG-2细胞凋亡。Western blot法检测结果显示JAK3和STAT3等蛋白的表达水平随药物浓度的增加而下降,而P53随药物浓度增加其表达量上升;凋亡相关因子Caspase-8的活性与对照组相比也均有不同程度的提高。结论香菇Latcripin-8蛋白结构域可能是通过JAK-STAT信号通路来诱导HepG-2肝癌细胞凋亡。  相似文献   

2.
目的:探讨Genistein增加顺铂诱导的耐药卵巢癌细胞SKOV-3凋亡的可能作用机制.方法:倒置相差显微镜下观察药物处理后细胞形态学的变化;MTT比色法检测不同药物处理后对SKOV-3细胞增殖的影响;流式细胞仪检测药物处理后细胞的凋亡情况;流式细胞仪和荧光显微镜检测细胞内活性氧(ROS)的水平.结果:10ug/ml的Genistein和2.5ug/ml的顺铂联用24h后,引起了细胞内ROS的增加,细胞的凋亡率也显著增高,与单用顺铂组相比差异有显著性(P<0.05);用NAC预处理细胞2h后,有效抑制了ROS的产生,并增加了细胞的活性,降低了细胞的凋亡率,与未加NAC组相比差异有显著性(P<0.05).结论:Genistein增加顺铂诱导的耐药卵巢癌细胞SKOV一3的凋亡与细胞内ROS水平的升高有关,这可能是Genistein增加顺铂诱导的耐药卵巢癌细胞SKOV-3凋亡的作用机制之一.  相似文献   

3.
为研究突变体rLj-112蛋白的抗肿瘤活性,人工合成七鳃鳗野生型rLj-RGD3蛋白和突变型rLj-112蛋白,通过比较两种蛋白质的抗增殖、迁移和促凋亡的活性,确定突变体rLj-112蛋白的生物学意义及地位。采用MTT方法检测不同浓度的rLj-112蛋白对HeLa细胞增殖的抑制作用。结果表明,rLj-112蛋白能显著抑制HeLa细胞的增殖,且IC50为4.3 μmol/L。使用Transwell细胞培养板对bFGF诱导的HeLa细胞迁移实验表明,rLj-112蛋白能抑制HeLa细胞的迁移。rLj-112蛋白作用后,HeLa细胞经Hoechst33258和AnnexinV-FITC染色结果显示,细胞均凋亡。流式细胞仪进一步证明,rLj-112蛋白能诱导HeLa细胞发生凋亡,且呈剂量依赖性。由此可见,与野生型rLj-RGD3蛋白比较,突变型rLj-112蛋白有较高的细胞毒性作用,具有抗肿瘤的功能,有望应用于抗肿瘤基因工程药物的开发,具有重要的生物学意义。  相似文献   

4.
目的:探讨Genistein对卵巢癌铂类耐药细胞CP70增殖、凋亡的影响及与细胞内活性氧水平的关系。方法:采用MTT法检测Genistein对CP70细胞增殖的影响;流式细胞仪分析不同药物处理后对细胞凋亡的影响,线粒体膜电位及细胞内ROS水平的变化情况。结果:Genistein对CP70细胞增殖表现出剂量和时间依赖性的抑制作用,并能诱导其凋亡;Genistein作用于CP70细胞后,可使其线粒体膜电位降低,并引发了细胞内ROS水平的显著升高;ROS抑制剂NAC预处理CP70细胞后,有效抑制了ROS的产生,并降低了细胞凋亡率,与未加NAC组相比差异有显著性(P0.05)。结论:Genistein能抑制铂类耐药卵巢癌细胞CP70的增殖,并促进其凋亡,这与细胞内ROS水平的升高有关,可能是Genistein抗肿瘤诱导细胞凋亡的机制之一。  相似文献   

5.
目的研究miR-423-3p在结肠癌5-氟尿嘧啶(5-Fu)耐药中的作用和机制。方法逆转录实验分析5-Fu耐药结肠癌组织和细胞中miR-423-3p的表达水平,MTT和流式细胞实验分析抑制miR-423-3p对5-Fu耐药结肠癌细胞活性和凋亡的影响,双荧光素实验检测5-Fu耐药结肠癌细胞中miR-423-3p的靶基因SUFU,Western blot研究miR-423-3p和Wnt信号通路抑制剂SUFU在结肠癌耐药性中的作用。结果 5-Fu耐药结肠癌组织和细胞中miR-423-3p表达显著升高,抑制miR-423-3p表达可显著降低5-Fu耐药结肠癌细胞细胞活性并增强细胞凋亡;SUFU是miR-423-3p的主要作用靶点,抑制miR-423-3p表达同时抑制SUFU可显著降低5-Fu耐药结肠癌细胞细胞凋亡。结论 miR-423-3p通过靶向SUFU影响结肠癌细胞对5-Fu敏感性。  相似文献   

6.
目的:探讨珊瑚树vibsane型二萜类化合物对肝癌HepG2细胞增殖的影响及其机制,为研发新型天然植物类抗肿瘤药物提供实验依据。方法:采用噻唑蓝比色法及苔盼蓝染色计数法观察珊瑚树vibsane类二萜类化合物对不同肿瘤细胞增殖的影响;应用流式细胞仪检测细胞周期及细胞凋亡,利用Apo-ONE Homogeneous Caspase-3/7试剂盒检测vibsane二萜类化合物1#对HepG2细胞内Caspase-3酶活性的影响。结果:活性筛选发现vibsane型二萜类化合物1#显著抑制人肝癌HepG2细胞增殖,构效分析表明化合物C11位连接侧链的基团修饰影响其细胞增殖抑制活性。此外,HepG2细胞对1#化合物最敏感,1#化合物抑制其增殖具有剂量和时间依赖性。机制研究显示1#化合物诱导HepG2细胞发生明显的细胞周期G0/G1期阻滞,具有时间和剂量效应;同时,较高浓度1#化合物(5-10μmol/L)引起HepG2细胞凋亡明显增加,并剂量依赖性诱导细胞内Caspase3/7激活。结论:珊瑚树vibsane型二萜类化合物能够明显抑制人肝癌HepG2细胞增殖,其可能通过诱导细胞周期阻滞和细胞凋亡发挥抗肿瘤作用。  相似文献   

7.
芹菜素是一种具有抗氧化、抗肿瘤和抗炎活性的天然植物黄酮,本研究应用MTT法测芹菜素对小鼠脾细胞和S180细胞增殖的影响,流式细胞仪测细胞凋亡和细胞内活性氧水平。结果显示:芹菜素剂量依赖地抑制小鼠脾细胞和S180细胞增殖,促进脾细胞和S180细胞凋亡,显著升高脾细胞和S180细胞内活性氧水平。这些结果提示:芹菜素可能通过升高不同细胞内ROS水平,诱导细胞凋亡,抑制细胞增殖,具有进一步研究开发价值。  相似文献   

8.
目的: 探讨紫草素对肝癌SMMC-772细胞的作用及分子机制。方法: SMMC-7721细胞分别经0、5、20、80、320 ng/ml的紫草素作用0 h、24 h、48 h和72 h后,适时采用CCK8法观察该细胞增殖的活性,hoechst染色分析细胞的核型变化,流式细胞仪检测细胞凋亡水平,Western blot证实细胞内蛋白表达水平的改变,通过小鼠体内实验观察该药的抑瘤作用。结果: 本研究体外实验发现紫草素可显著抑制SMMC-7721细胞的增殖活性并诱导其凋亡(P<0.01),上调基因p53的表达,并抑制AKT、PI3K蛋白的磷酸化,体内实验也证实紫草素可显著抑制荷瘤小鼠肿瘤的生长(P<0.01),作用效果随用药剂量和时间的增加而增加。结论: 紫草素可通过影响PI3K/AKT信号通路抑制SMMC-7721细胞的增殖,且诱导其凋亡,具有潜在的抗肝癌作用。  相似文献   

9.
三氧化二砷对K562细胞凋亡的诱导及生长抑制作用的研究   总被引:3,自引:0,他引:3  
目的:研究三氧化二砷(As2O3)对人红白血病细胞株K562的生长抑制和凋亡诱导作用。方法:以As2O3作为耐药逆转剂,用台盼兰排染法,噻唑兰(MTT)还原法,Hoechst 33342和PI荧光染色法,流式细胞仪技术和荧光分光光度法,观察了不同浓度的As2O3(0.2—5.0μmol/L)对人红白血病细胞株K562的生长抑制和凋亡诱导作用。结果:As2O3对K562细胞具有明显生长抑制和凋亡诱导作用,其作用强度在一定范围内均具药物浓度和时间依赖性。结论:As2O3主要以诱导肿瘤细胞凋亡而表现其毒性作用。  相似文献   

10.
目的:探讨杨芽黄素对前列腺癌细胞22Rv.1的作用及机制。方法:将0~20μg/ml杨芽黄素作用于22Rv.1细胞和正常前列腺细胞RWPE-1,适时采用MTS法检测细胞的增殖活性,采用流式细胞仪、hoechst染色、LDH释放实验分别检测22Rv.1细胞凋亡、死亡、周期、核型变化和药物的细胞毒作用,利用qPCR和Westernblot分析22Rv.1细胞内基因转录和蛋白表达的改变,并通过抑瘤实验证实该药的抑癌作用。结果:杨芽黄素可显著抑制22Rv.1细胞增殖、诱导其凋亡,促进22Rv.1细胞凋亡相关基因dr4、dr5、trail、p53、caspase-3、caspase-8、caspase-9、bid、bax、foxo3的表达,并抑制抗凋亡基因akt、pi3k和bcl-2的表达。结论:杨芽黄素可通过影响TRAIL和PI3K/AKT信号通路诱导前列腺癌细胞凋亡,具有抗前列腺癌的作用。  相似文献   

11.
5-Fluorouracil (5-Fu) is commonly used in the chemotherapy of colorectal cancer (CRC), but resistance to 5-Fu occurs in most cases, allowing cancer progression. Suppressing ABCB1 (ATP-binding cassette, subfamily B, member 1), which is a pump overproduced in cancer cells to export cytotoxic drugs, is an attractive strategy to overcome drug resistance. In the present study, transient receptor potential channel TrpC5 was found to be overproduced at the mRNA and protein levels together with ABCB1 in 5-Fu-resistant human CRC HCT-8 (HCT-8/5-Fu) and LoVo (LoVo/5-Fu) cells. More nuclear-stabilized β-catenin accumulation was found in HCT-8/5-Fu and LoVo/5-Fu cells than in HCT-8 and LoVo cells. Suppressing TrpC5 expression with TrpC5-specific siRNA inhibited the canonical Wnt/β-catenin signal pathway, reduced the induction of ABCB1, weakened the ABCB1 efflux pump, and caused a remarkable reversal of 5-Fu resistance in HCT-8/5-Fu and LoVo/5-Fu cells. On the contrary, enforcing TrpC5 expression resulted in an activated Wnt/β-catenin signal pathway and up-regulation of ABCB1. Taken together, we demonstrated an essential role of TrpC5 in ABCB1 induction and drug resistance in human CRC cells via promoting nuclear β-catenin accumulation.  相似文献   

12.
方兴  钟章成 《生态学报》2012,32(23):7411-7420
以谷子(Setaria italica(L)Beauv.)为对象,从拔节期开始持续给予低氮(1.875 mmol/L)和高氮(15 mmol/L)两种氮供应条件并从抽穗期开始进行26 d两种强度(4.29、7.12 kJ·m-2·d-1)的增强UV-B辐射处理,研究了谷子叶中光合色素含量、类黄酮含量和苯丙氨酸解氨酶(PAL)活性的变化.结果表明:与高氮供应条件相比,低氮供应条件明显降低了谷子叶中光合色素含量但提高了类胡萝卜素/叶绿素含量比值;在开花期中段和灌浆期中段,高氮供应条件下谷子叶中光合色素含量对增强UV-B辐射比低氮供应条件下的谷子更敏感.从灌浆期开始到处理结束,两种影响因子对谷子叶中类黄酮含量均有显著影响,增强UV-B辐射导致谷子叶中类黄酮含量逐渐升高,且相同增强UV-B辐射强度下低氮供应条件下的谷子叶中类黄酮含量明显高于高氮供应条件下的谷子.谷子叶中PAL活性对两种影响因子的响应较类黄酮含量更加敏感,低氮供应条件使谷子叶中PAL活性明显提高.结合上述指标的相关性分析结果可知,低氮供应条件加强了处于繁殖期主要阶段的谷子叶中类黄酮的积累,并使谷子叶中的类胡萝卜素/叶绿素含量比值明显提高,进而有助于维持谷子叶中光合色素含量在增强UV-B辐射条件下的相对稳定性,对植株抵抗UV-B辐射伤害有利.  相似文献   

13.
Upon UV-B irradiation, Chlorella vulgaris cells and isolated chloroplasts increased in size and starch accumulation . Photosynthetic capacity and chlorophyll content of chloroplasts isolated from irradiated algae decreased by 72 and 66%, as compared to chloroplasts isolated from control cells. Dihydrorhodamine 123 conversion to rhodamine 123 was used as a sensitive method for detection of peroxide (presumably hydrogen peroxide) formation in isolated chloroplasts. The accumulation of rhodamine 123 is higher in irradiated than in nonirradiated chloroplasts and the increased accumulation of rhodamine 123 depended on the UV-B dose. Quantitation of alkyl radical-EPR signals in chloroplasts indicated that UV-B exposure significantly increased radical content in the membranes. The content of an oxidized DNA base (8-hydroxy-2'-deoxyguanosine) in chloroplasts was increased by 72 and 175% after irradiation of the algal culture with 17.3 and 42.6 kJ m−2, respectively. The chloroplastic activity of superoxide dismutase decreased by 50% as compared with control values after irradiation with 42.6 kJ m−2 and no changes in ascorbate peroxidase activity and ascorbic acid content were detected at the irradiation doses tested. The β-carotene content in chloroplasts was not affected by the irradiation, but the α-tocopherol content increased approximately 4-fold after UV-B irradiation. The results suggest that oxidative damage related to UV-B exposure is responsible for alterations in chloroplasts function and integrity, and that an antioxidant response is triggered in chloroplasts through an increase in α-tocopherol content.  相似文献   

14.
A series of substituted dibenzo[c,e]azepine-5-ones (7a-h) were synthesized and evaluated as P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) reversal agents. The most potent compound 7h could significantly and selectively enhance the chemo-sensitivity of drug-resistant K562/A02 cells to the cytotoxic effect of adriamycin (ADR) in a dose-dependent manner. Further studies indicated that 7h could markedly increase intracellular accumulation of both rhodamine 123 and ADR in K562/A02 cells and inhibit their efflux from the cells. And 7h had little effect on the levels of P-gp mRNA and protein in K562/A02 cells. These results suggest that the anti-MDR effect of 7h might be attributed to the inhibition of drug efflux function of P-gp, leading to the increased drug accumulation in K562/A02 cells, and thus the compound could be served as a lead for developing P-gp-mediated MDR reversal agents.  相似文献   

15.
《Phytomedicine》2014,21(8-9):1110-1119
The overexpression of ABC transporters is a common reason for multidrug resistance (MDR) in cancer cells. In this study, we found that the isoquinoline alkaloids tetrandrine and fangchinoline from Stephania tetrandra showed a significant synergistic cytotoxic effect in MDR Caco-2 and CEM/ADR5000 cancer cells in combination with doxorubicin, a common cancer chemotherapeutic agent. Furthermore, tetrandrine and fangchinoline increased the intracellular accumulation of the fluorescent P-glycoprotein (P-gp) substrate rhodamine 123 (Rho123) and inhibited its efflux in Caco-2 and CEM/ADR5000 cells. In addition, tetrandrine and fangchinoline significantly reduced P-gp expression in a concentration-dependent manner. These results suggest that tetrandrine and fangchinoline can reverse MDR by increasing the intracellular concentration of anticancer drugs, and thus they could serve as a lead for developing new drugs to overcome P-gp mediated drug resistance in clinic cancer therapy.  相似文献   

16.
Epidemiological studies have indicated that obesity is associated with colorectal cancer. The obesity hormone leptin is considered as a key mediator for cancer development and progression. The present study aims to investigate regulatory effects of leptin on colorectal carcinoma. The expression of leptin and its receptor Ob-R was examined by immunohistochemistry in 108 Chinese patients with colorectal carcinoma. The results showed that leptin/Ob-R expression was significantly associated with T stage, TNM stage, lymph node metastasis, distant metastasis, differentiation and expression of p-mTOR, p-70S6 kinase, and p-Akt. Furthermore, the effects of leptin on proliferation and apoptosis of HCT-116 colon carcinoma cells were determined. The results showed that leptin could stimulate the proliferation and inhibit the apoptosis of HCT-116 colon cells through the PI3K/Akt/mTOR pathway. Ly294002 (a PI3K inhibitor) and rapamycin (an mTOR inhibitor) could prevent the regulatory effects of leptin on the proliferation and apoptosis of HCT-116 cells via abrogating leptin-mediated PI3K/Akt/mTOR pathway. All these results indicated that leptin could regulate proliferation and apoptosis of colorectal carcinoma through the PI3K/Akt/mTOR signalling pathway.  相似文献   

17.
采用盆栽土培法,研究了4种基因型谷子幼苗对Pb2+、Cu2+胁迫的生长响应、DNA损伤及吸收积累、迁移特性。结果表明,D2-8、安06、黄米和朝谷幼苗对Pb2+、Cu2+的平均耐性指数分别为0.87、0.81、0.78、0.71和0.96、0.97、0.79、0.74。在400 mg/kg Pb2+、Cu2+浓度下,4种谷子幼苗叶绿素a、b总量分别为对照的33.3%、52.6%、37.5%、49.4%和113.5%、72.3%、51.9%、75.6%,而叶绿素a/b值均高于对照。Pb2+胁迫下4种谷子幼苗中可溶性蛋白质和DNA含量随浓度升高逐渐下降,Cu2+处理组则表现为低浓度(≤100 mg/kg)的促进和高浓度(≥200 mg/kg)的抑制效应。4种谷子幼苗的DNA增色效应值在Pb2+、Cu2+胁迫下均表现为先上升后下降的趋势,其中Pb2+对朝谷和D2-8的增色效应影响较大,而Cu2+对朝谷和安06的影响最为明显。D2-8和朝谷对Pb2+、Cu2+的吸收富集能力高于安06和黄米,D2-8和安06对Pb2+、Cu2+的转运能力大于朝谷和黄米。总体来看,Pb2+对谷子幼苗的生理生态影响和遗传毒害效应大于Cu2+,4种基因型谷子对Pb2+胁迫的耐性顺序为安06>D2-8>黄米>朝谷,对Cu2+的耐性顺序为D2-8>安06>朝谷>黄米。  相似文献   

18.
In this study, the effect of irrigation with raw or diluted municipal sewage effluent accompanied by foliar micronutrient fertilizer sprays was examined on the growth, dry matter accumulation, grain yield, and mineral nutrients in foxtail millet plants. The experimental design was a split plot with three irrigation sources: raw sewage, 50% diluted sewage, and well water comprising the main treatments, and four combinations of Mn and Zn foliar sprays as sub-treatments that were applied with four replications. The experiment was conducted in 2009 at the Zabol University research farm in Zabol, south Iran. The applied municipal sewage effluent contained higher levels of micronutrients and macronutrients and exhibited greater degrees of electrical conductivity compared to well water. Because of the small scale of industrial activities in Zabol, the amount of heavy metals in the sewage was negligible (below the limits set for irrigation water in agricultural lands); these contaminants would not be severely detrimental to crop growth. The experimental results indicated that irrigation of plants with raw or diluted sewage stimulates the measured growth and productivity parameters of foxtail millet plants. The concentrations of micronutrients and macronutrients were also positively affected. These stimulations were attributed to the presence of high levels of such essential nutrients as N, P, and organic matter in wastewater. Supplied in sewage water alone, Mn and Zn were not able to raise the productivity of millet to the level obtained using fertilizers at the recommended values; this by itself indicated that additional nutrients from fertilizers are required to obtain higher levels of millet productivity with sewage farming. Despite the differences in nutrient concentrations among the different irrigation water sources, the micronutrient foliar sprays did not affect the concentrations of micronutrients and macronutrients in foxtail millet plants. These results suggested that municipal sewage effluent could be utilized efficiently as an important source of water, and that the nutrients used in growing foxtail millet with sewage water irrigation did not have any significant harmful effect on crop productivity. In contrast, the nutrients proved beneficial to soil fertility and millet productivity and quality.  相似文献   

19.
Comparative genetic maps were constructed of the pearl millet genome with foxtail millet and used to describe the homoeology between the genomes of pearl millet, foxtail millet and rice. Despite the close taxonomic relationship of pearl and foxtail millet, their genomes were highly, rearranged. A comparison of the millet and rice genomes indicated that most of these rearrangements were likely to have taken place in pearl millet. Two duplications were identified in pearl millet. A duplication between the distal segments of linkage groups 1 and 4 corresponds to the ancient duplication previously identified between rice chromosome arms 11S and 12S and foxtail millet chromosomes VII and VIII. The other putative duplication, also between regions of linkage groups 1 and 4, is likely to be species-specific. The exploitation of the comparative maps in pearl millet research is discussed. Received: 10 February 1999 / Accepted: 6 July 1999  相似文献   

20.
株型是影响谷类作物产量的重要性状, 株型改良对提高作物产量具有重要意义。独脚金内酯(strigolactones, SLs)作为一种最新被鉴定的植物激素, 其通过抑制腋芽的伸长调控分枝/分蘖的形成。β-胡萝卜素异构酶(D27s)是SLs合成途径的关键酶, 通过对谷子(Setaria italica) β-胡萝卜素异构酶典型结构域Pfam:DUF4033进行分析, 鉴定到3个谷子D27s基因家族成员(Seita.8G168400Seita.6G088800Seita.3G050900)。蛋白质特性分析显示, 谷子D27s蛋白由271-277个氨基酸残基组成, 分子量为30.1-30.4 kDa, 等电点为5.85-9.31, 不稳定系数介于38.48-74.47之间, 且均定位于叶绿体; 系统进化分析发现, 谷子D27s家族成员位于3个不同进化分支; 顺式作用元件预测显示, SiD27-1 (Seita.8G168400)可能参与调控生物节律、生长素介导的生长发育以及干旱和低温等胁迫应答过程。基因表达分析显示, SiD27-1在谷子多分蘖材料中表达下调, 在低磷胁迫处理下, D27s基因均能产生不同程度的响应, 并且SiD27-1的响应较其它成员更快速。单倍型分析结果表明, SiD27-1的H001单倍型为优异单倍型, 对谷子的株高、抽穗期和产量改良具有重要应用价值。综上, 推测SiD27-1极可能在SLs合成中发挥关键作用并对谷子株型产生影响。研究结果为深入揭示D27s对谷子分蘖形成的调控机制奠定了基础, 也为谷子株型分子设计育种提供了优异的等位变异位点。  相似文献   

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