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1.
姜黄素诱导肺癌A549细胞凋亡   总被引:1,自引:0,他引:1  
目的:研究姜黄素对A549细胞凋亡的诱导作用,并探讨其可能的分子机制。方法:姜黄素处理A549细胞后,MTT法于不同时间点检测A549细胞的增殖情况;姜黄素处理A549细胞48h后,流式细胞术(Flow CytoMetry,FCM)检测A549细胞的凋亡率;30μmol/L姜黄素处理A549细胞24h、48h、72h后,RT—PCR、Western—Blot检测A549细胞中P53、Bcl2、Bax和cagpase-3基因的表达水平。结果:姜黄素对肺癌A549细胞增殖的抑制作用具有显著的浓度-时间依赖关系,30μmol/L姜黄素可诱导A549细胞凋亡。30μmoL/L姜黄素作用A549细胞24h即可引起A549细胞中P53、Bax和Caspase-3表达水平的上调,48h后可引起Bcl2表达水平的下调,诱导A549细胞凋亡。结论:30μmol/L姜黄素可诱导A549细胞凋亡,其机制可能与促进P53、Bax和Caspase-3基因的表达,抑制Bcl2基因的表达有关。  相似文献   

2.
BPD-MA光动力作用对膀胱癌细胞凋亡及bcl-2蛋白表达的影响   总被引:3,自引:0,他引:3  
目的:研究激光活化BPD-MA光动力诱导肿瘤细胞凋亡及其可能机制。方法:应用流式细胞仪分析BPD-MA光动力作用后细胞凋亡及免疫组化染色检测凋亡相关蛋白bcl-2蛋白表达水平。结果:激光活化BPD-MA光动力实验组人膀胱癌细胞株BIU-87凋亡发生率达26.11±2.59%,与对照组相比,差异非常显著性(P<0.01);光动力作用后膀胱癌细胞线粒体相关调控蛋白bcl-2表达显著低于对照组(P<0.05)。结论:激光活化BPD-MA光动力作用具有诱导人膀胱癌细胞株BIU-87凋亡的生物效应,而线粒体相关调控蛋白bcl-2表达水平的降低可能是激光活化BPD-MA光动力诱导人膀胱癌细胞株BIU-87凋亡的重要机制之一。  相似文献   

3.
目的:从形态学角度探寻自噬小体形成过程中的膜来源及自噬小体的超微结构特征.方法:应用透射电镜技术整理分析本中心收到的用于自噬研究的细胞标本,对自噬发生不同阶段及疑似自噬小体结构的图片进行分析.结果:在细胞内发现众多自噬小体结构,内质网、线粒体、细胞核和高尔基体均可形成类似自噬小体结构.结论:细胞内多种膜结构可能都是自噬小体的膜来源.  相似文献   

4.
自噬是真核生物进化过程中高度保守的分解代谢和循环再利用的过程,在维持细胞状态、内环境稳态,尤其是在细胞营养不足、氧化损伤等不利环境时起着重要作用。近来研究发现自噬参与了光动力疗法的作用过程,其机制较为复杂,而且不同程度的自噬对光动力疗法杀伤效应的影响截然不同。光动力疗法是利用特定波长的光照激活光敏剂分子,通过能量转换促使活性氧的产生并通过氧化损伤杀伤病变细胞。目前光动力疗法在各类型的肿瘤、皮肤炎症、创伤愈合、尖锐湿疣等方面是一种很有前景的临床治疗手段,既往研究表明,光动力疗法能影响细胞自噬,调控细胞自噬能影响光动力疗法的疗效。就光动力疗法如何诱导自噬和自噬在光动力疗法中的作用机制研究进展进行阐述。  相似文献   

5.
石墨烯及其衍生物纳米材料因具有独特的物理化学性质,被广泛应用于生物医学领域,常被用作抗肿瘤药物的载体。本研究旨在探索氧化石墨烯对非小细胞肺癌细胞A549的生长和迁移的影响及机制。主要实验方法包括live/dead染色、Transwell实验、免疫印迹及原子力显微镜、激光共聚焦显微镜、透射电子显微镜、扫描电子显微镜等显微成像技术。结果显示GO能够穿透细胞膜切入细胞,导致细胞骨架肌动蛋白丝的形态结构发生显著改变;GO能够大量吸附细胞裂解物中F-actin蛋白。这些结果提示GO进入细胞后,可能通过吸附F-actin,破坏细胞骨架的结构,进而影响A549细胞的生长和转移。这些发现为未来以GO为载体的抗肿瘤药物设计提供了新的理论依据。  相似文献   

6.
人肝细胞自噬性凋亡的形态学观察   总被引:1,自引:0,他引:1  
为了进一步完善形态学的分型标准以及研究调控自噬对细胞凋亡的影响 ,采用去血清诱导自噬和3MA抑制自噬 ,同时施与凋亡诱导剂 ,观察细胞超微结构的改变。正常人肝LO2细胞株去血清培养12h诱导自噬之后 ,cisplatin(3μl ml)加入 16 40培养基诱导LO2细胞凋亡 16h和 3-MA自噬抑制剂(6 0 0 μg ml) ,30min后加入cisplatin(3μl ml)混合培养LO2细胞 16h。JEM 12 0 0EX透射电镜观察、摄片。正常LO2细胞胞质丰富 ,核仁明显 ,自噬现象少见。单施加凋亡诱导剂的细胞 ,可见凋亡细胞的形态多样 ,细胞…  相似文献   

7.
显微镜技术在植物细胞自噬研究中的应用   总被引:1,自引:0,他引:1  
细胞自噬是真核生物对细胞内物质进行循环利用的重要途径.在植物中已发现的细胞自噬有两种形式,即微自噬和巨自噬.自噬在植物体的生长发育、免疫应答、胁迫反应、衰老等过程中具有非常重要的作用.显微镜技术是研究细胞自噬的重要手段,与生物化学和分子生物学技术相结合,荧光显微镜,激光扫描共聚焦显微镜,电子显微镜等技术的相互印证,大大地推动了对细胞自噬过程和机理的研究.本文扼要概述了显微镜技术在植物细胞自噬研究中的应用.  相似文献   

8.
目的:探讨核因子-κB(nuclear factor-KB,NF-κB)在冬凌草甲素(Oridonin,Ori)诱导急性淋巴细胞白血病Molt-4细胞凋亡中的作用.方法Ori单用或联合NF-κB抑制剂吡咯烷二硫氨基甲酸(PDTC,50μmol/L)处理Molt-4细胞,MTT法检测细胞增殖的变化,流式细胞术检测细胞凋亡,Westem blot技术检测NF-κB p65蛋白表达水平.结果Ori对Molt-4细胞生长有显著抑制作用,可诱导细胞凋亡并抑制NF-κBp65蛋白表达,PDTC增加了Ori的上述作用.结论:Ori可诱导Molt-4细胞凋亡,其机制可能与抑制NF-κB活性有关.  相似文献   

9.
本文建立了一种主动脉不完全结扎慢性心力衰竭的动物模型,并研究了其超微结构变化。慢性心力衰竭的心肌存在不同类型的心肌细胞变性:(一)严重变性的心肌细胞胞质内充满增生的线粒体,肌原纤维被取代;(二)变性细胞中大片肌原纤维溶解,肌浆网小管和小泡增殖,粗面内质网丰富,溶酶体活跃;(三)变性细胞肌原纤维完整而线粒体全部被溶酶体自噬破坏。与此同时,还经常观察到线粒体灶性增生、肌原纤维灶性溶解以及走向紊乱等局灶变性改变。结果表明:心肌细胞的肌原纤维和线粒体破坏导致心肌收缩性障碍,可能是心力衰竭发生的重要机制。  相似文献   

10.
低能量激光照射(LPLI)可以调节多种生物过程.大量的实验结果表明它能够促进细胞增殖与分化.最近的研究表明高通量的低能情激光照射(HF-LPLDI)可以诱导细胞凋亡.低能量激光照射可以影响多种细胞内生理指标的水平.其中活性氧(ROS)的产生被认为是低能量激光照射引起的细胞生物效应中关键的因素.在分子水平上,低能量激光引起的细胞生物效应主要由一些信号蛋白来执行,简要介绍了低能量激光照射引起生物效应的研究进展,重点介绍了低能量激光照射的光化学本质,以及引起的细胞增殖和凋亡效应的分子机制.  相似文献   

11.
Gold nanorods have received much attention because of their distinct physicochemical properties and promising applications in bioimaging, biosensing, drug delivery, photothermal therapy, and optoelectronic devices. However, little is known regarding their effect on tumor metastasis. In the present investigation, serum protein‐coated gold nanorods (AuNRs) at low concentrations is shown to exhibit no apparent effects on the viability and proliferation of three different metastatic cancer cell lines, that is, MDA‐MB‐231 human breast cancer cells, PC3 human prostate cancer cells, and B16F10 mouse melanoma cells, but effectively inhibit their migration and invasion in vitro. Quantitative proteomics and real‐time PCR array analyses indicate that exposure of cells to AuNRs can down‐regulate the expression of diverse energy generation‐related genes, which accounts for their inhibition of mitochondrial oxidative phosphorylation (OXPHOS) and glycolysis. The impairment of OXPHOS and glycolysis results in a distinctive reduction of ATP production and subsequent inhibition of F‐actin cytoskeletal assembly, which is crucial for the migration and invasion of cancer cells. The inhibitory effect of AuNRs on cancer cell migration is also confirmed in vivo. Taken together, the unique mechanism in inhibiting cancer cell migration by AuNRs might provide a new approach to specific cancer therapeutic treatment.  相似文献   

12.
The nanoscale anisotropic patterns of bioactive ligands in the extracellular matrix regulate cell adhesion behaviors. However, the mechanisms of such regulation remain unclear. Here, RGD‐bearing gold nanorods (AuNRs) are conjugated with different aspect ratios (ARs, from 1 to 7) on cell culture substrates to decouple the effect of nanoscale anisotropic presentation of cell adhesive RGD peptides on cell adhesion. Compared with AuNRs with small ARs, AuNRs with large ARs significantly promote cell spreading, the alignment of the basal cytoskeletal structure, and nanopodia attachment. Furthermore, both ‐β3 and ‐β1 class integrins are recruited to AuNRs with large ARs, thereby promoting the development of focal adhesion toward fibrillar adhesion, whereas the recruitment of diverse integrins and the development of cell adhesion structures are hindered by small ARs AuNRs. The anisotropic presentation of ligands by large AR AuNRs better activates mechanotransduction signaling molecules. These findings are confirmed both in vitro and in vivo. Hence the enhanced mechanotransduction promotes osteogenic differentiation in stem cells. These findings demonstrate the potential use of well‐controlled synthetic nanoplatforms to unravel the fundamental mechanisms of cell adhesion and associated signaling at the molecular level and to provide valuable guidance for the rational design of biomaterials with tailored bioactive functions.  相似文献   

13.
李红梅  王导新 《激光杂志》2010,(3):90-90,92
目的;通过体外给药的方式观察辛伐他汀对人类肺泡上皮细胞(A549细胞代替)膜上阿米洛利敏感型钠离子通道α亚基(ENaC-α)表达的影响。方法:细胞株培养,分为空白组、2.5μM组、5μM组、10μM组,培养24小时,western blot检测ENaC-α膜蛋白表达,RT-PCR检测ENaC-αmRNA表达。结果:结果显示:2.5μM组ENaC-α膜蛋白与空白组无明显差别(P〉0.05),5μM组高于空白组(P〈0.05),10μM组明显高于空白组(P〈0.01);2.5μM组ENaC-αmRNA与空白组无明显差别(P〉0.05),5μM组表达增加(P〈0.05),10μM组显著增加(P〈0.01)。结论:大剂量辛伐他汀增强A549细胞膜上ENaC-α膜蛋白及mRNA的表达。  相似文献   

14.
Targeted delivery of drug-loaded nanoparticles to brain tumors is exceptionally difficult due to the blood-brain barrier (BBB). In addition, several chemotherapeutic drugs induce autophagy, which protects the cells from apoptosis and mitigates the therapeutic effect. A novel “all-in-one” nanoparticles (AMPTL) consisting of endogenous reactive oxygen species-cleavable thioketal linkers conjugated to paclitaxel (PTX) and autophagy inhibitor 3-methyladenine, and angiopep-2 peptide-modified DSPE-PEG2K is developed. AMPTL inhibits autophagy in the C6 glioma cells, as indicated by fewer autophagic vesicles, lower LC3-II expression and accumulation of SQSTM1/P62, and significantly upregulates p53 and the pro-apoptotic Bax and cleaved caspase-3 proteins. In addition, AMPTL treatment induces cell cycle arrest at the G2/M phase. Thus, inhibition of autophagy in the AMPTL-treated glioma cells sensitizes them to PTX-induced cell cycle arrest and apoptosis. Furthermore, focused pulse ultrasound and microbubbles enhances the delivery of AMPTL to intracranial glioma tissues by reversibly opening the BBB, which significantly inhibits xenograft growth and markedly improves survival rates of the tumor-bearing mice. Taken together, combining non-invasive BBB opening with autophagy inhibitors and chemotherapeutic drugs can achieve cascade-amplifying synergistic therapeutic effects against glioma.  相似文献   

15.
本文应用原子力显微镜对人胃癌SGC7901、人肝癌HepG2、人肺癌AFFC-A-1、人乳腺癌MCF.7.R和人肺腺癌A549等肿瘤细胞膜表面进行了超微结构的形态学观察和比较。并研究了Nm23-Hl/NDPK-A蛋白对人肺腺癌A549等细胞膜表面超微结构的影响。发现不同肿瘤细胞膜表面超微结构存在较大的差异,药物处理和对照组A549细胞膜的表面超微结构也存在较大差异,药物处理的A549细胞膜表面出现大量的疤痕状集聚物,而药物处理的其它几种肿瘤细胞膜表面未发现明显的变化。说明原子力显微镜具有发展为一种观察和鉴别某些细胞的有力工具的潜力,并有可能应用于病理学或药理学研究,但在这些研究中这种技术只能作为一种辅助手段。  相似文献   

16.
Exploiting a comprehensive strategy that processes diagnosis and therapeutic functions is desired for eradicating tumors. In this study, two versatile nanoparticles are introduced: one is polyethylene glycol- and polyethyleneimine-modified gold nanorods (mPEG–PEI–AuNRs), and the other is formed by electrostatic interactions between mPEG–PEI and calcium carbonate nanoparticles (mPEG–PEI/CaNPs). These two nanoparticles possess following favorable properties: 1) mPEG–PEI–AuNRs and mPEG–PEI/CaNPs show not only high cell uptake in acidic tumoral pH, but also efficient accumulation in tumors with prolonged circulation. 2) mPEG–PEI/CaNPs can generate carbon dioxide (CO2) bubbles in acidic tumoral environment and the photoacoustic (PA) signals from mPEG–PEI–AuNRs can be enhanced with the generation of CO2 bubbles. 3) The tumors can be eradicated by combining photothermal therapy (PTT) with ultrasonic therapy (UST) under the near-infrared (NIR) laser and ultrasonic irradiation with the presence of mPEG–PEI–AuNRs and CO2 bubbles from mPEG–PEI/CaNPs. The detailed evaluation of cellular uptake, photothermal property of mPEG–PEI–AuNRs, CO2 bubbles’ generation from mPEG–PEI/CaNPs, imaging, and combined PTT and UST are carried out in vitro or in vivo. This work has great potential usage for diagnosis and treatment in the future.  相似文献   

17.
This paper reports dual function Gd2O3/C nanoshells for application in MR contrast images and NIR‐triggered killing cancer cells. The nanoshells are prepared using biological gelatin particles as core templates through a two‐step thermal treatment. The surfaces of the nanoshells can be readily modified by poly(styrene‐alt‐maleic acid) (PSMA) polymer to improve their water‐dispersible properties and increase their biocompatibility. The Gd2O3/C nanoshells show brightened images of kidney cortex and liver in mice, whereas the Gd2O3/C@PSMA nanoshells show a darkened liver signal. The biodistribution is measured as a function of time and shows that the nanoshells circulate in the vessels and are cleared out gradually from organs. The graphite carbon coated on the Gd2O3 nanoshells displays absorbance in the near‐IR (NIR) region. A large extinction coefficient is obtained, indicating the potential of the nanoshells as photothermal agents. The Gd2O3/C@PSMA nanoshells conjugated with anti‐epithermal growth factor receptor antibodies are used for targeting and destroying A549 lung cancer cells by means of NIR‐triggered killing capability. Both laser power density and material dose dependence are investigated to evaluate photothermolysis in cancer cells.  相似文献   

18.
The surface of layered double hydroxide nanoparticles, a potential drug‐delivery nanovehicle, is modified with the cancer‐cell‐specific ligand, folic acid. The surface modification is successfully accomplished through step‐by‐step coupling reactions with aminopropyltriethoxysilane and 1‐ethyl‐3‐(3‐dimethyl aminopropyl)‐carbodiimide. In order to evaluate the cancer‐cell targeting effect of folic‐acid‐grafted layered double hydroxide utilizing fluorescence‐related assay, both layered double hydroxide with and without folic acid moiety are labeled with fluorescein 5′‐isothiocyanate. The uptake of layered double hydroxide and folic acid conjugated into KB and A549 cells is visualized using fluorescence microscopy and measured by flow cytometry. Both chemical and biological assay results demonstrate that the folic acid molecules are indeed conjugated to the surface of layered double hydroxide and thus the selectivity of nanovehicles to cancer cells overexpressing folate receptors increases. In this study, it is suggested that layered double hydroxide nanoparticles can be used as drug‐delivery carriers with a targeting function due to the chemical conjugation with specific ligand.  相似文献   

19.
A promising theranostic platform for solid tumors would deliver and release anticancer nanomedicine effectively in tumor cells. However, diverse biological barriers, especially related to the tumor microenvironment, impede these theranostic agents from reaching the tumor cell. Herein, a sequential pH and reduction‐responsive polymer and gold nanorod (AuNR) core–shell assembly to overcome these barriers via a two‐stage size decrease and disassembly of the nanoplatform responding to the specified tumor microenvironment are reported. The tumor uptake of the hybrid nanoparticle (NP) is 14.2% ID g?1, which is two and four times higher than the noneresponsive hybrid NPs and small AuNR@PEG, respectively. After tumor uptake of the hybrid NPs, the disassembled ultrasmall AuNRs coated with a polymer of polymerized reduction‐responsive doxorubicin (DOX) prodrug monomers penetrate into the solid tumor and lead to localized DOX release in the tumor cell. A linear increase in photoacustic (PA) effects from the PA activating polymer on an AuNR cluster surface indicates a critical role of electromagnetic fields in the AuNR assembly, which is consistent with the theoretical calculation results. Furthermore, the hybrid NP can serve as a promising deep‐tissue PA and surface‐enhanced Raman scattering imaging agent for real‐time in vivo investigation of physiological behaviors and deep tumor penetrating nanotherapy effects.  相似文献   

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