黏附分子αvβ3和αvβ5介导肿瘤细胞与肿瘤内皮细胞的黏附

目的 体外分析黏附分子αvβ3和αvβ5及其配体Del-1、L1在肿瘤细胞-内皮细胞黏附中的作用.方法 应用逆转录聚合酶链反应(RT-PCR)和流式细胞分析比较正常肝窦内皮细胞(LSEC)和肝癌的血管内皮细胞T3A上细胞间黏附分子1(ICAM-1)、αvβ3和αvβ5的表达以及缺氧对其表达的调控.分别用RT-PCR和Western blot方法分析6种肿瘤细胞Del-1和L1的表达及缺氧对其表达的调控.使用连续光谱荧光测定仪定量肿瘤细胞在LSEC和T3A上的黏附,并分析抗不同黏附分子的抗体和siRNA对肿瘤细胞一内皮细胞黏附的阻断作用.结果 T3A细胞αvβ3和αvβ5的基础表达高于LSEC,而ICAM-1的基础表达低于LSEC.缺氧上调两种内皮细胞αvβ3和αvβ5的表达,而ICAM-1表达仅在LSEC中升高.在不同肿瘤细胞中,Del-1和L1的基础表达存在明显差异,并且在缺氧条件下受到明显不同的调节.Del-1和L1高表达的肿瘤细胞在T3A细胞的黏附明显高于LSEC,并且在缺氧条件下黏附明显增加,这种黏附可以被抗αvβ3、αvβ5的抗体或沉默β3和β5的小干扰RNA(siRNA)阻断.结论 细胞黏附分子αvβ3、αvβ5及其配体在肿瘤细胞-肿瘤内皮细胞的黏附过程中起重要介导作用.     

整合素αvβ3在肿瘤血管生成中的作用

整合素是一种重要的黏附分子，整合素αvβ3是整合素家族中的重要成员。作为内皮细胞与细胞外基质的桥梁，整合素αvβ3通过调节内皮细胞的黏附、迁移、增殖、凋亡等功能，在肿瘤血管生成的过程中发挥重要的作用。整合素αvβ3的单克隆抗体和拮抗剂能抑制肿瘤血管的生成．可能是一种治疗肿瘤的新途径。     

雷公藤甲素对血管内皮细胞尿激酶型纤溶酶原激活物表达的影响

背景与目的已有研究发现雷公藤具有抗肿瘤的作用,本研究旨在观察雷公藤甲素(triptolide,T10)对血管内皮细胞增殖和尿激酶型纤溶酶原激活物(urokinase-typeplasminogenactivator,u-PA)表达的影响,探讨T10抑制血管生成的机制。方法体外培养人脐静脉内皮细胞,传至第三代,加入不同浓度的T10(0、5、10、20、30μg/L)、地塞米松(300mg/L)后培养不同时间,计数细胞以了解细胞的增殖情况;培养48h,采用[3H]-TDR掺入法检测DNA的合成情况;利用鸡胚尿囊膜在体观察T10对血管生成的影响;免疫组织化学染色检测内皮细胞u-PA的蛋白表达;荧光定量RT-PCR检测u-PAmRNA的表达。结果T10可抑制内皮细胞的增殖,并且呈明显的剂量依赖性,5μg/LT10的抑制率达28.93%;可明显抑制鸡胚尿囊膜的血管生成(P<0.05);减少内皮细胞u-PA的蛋白表达,并呈剂量依赖趋势,5μg/LT10使内皮细胞u-PA表达降低41.05%;荧光定量RT-PCR结果显示,T10可下调u-PAmRNA的表达。结论雷公藤甲素可有效抑制血管内皮细胞的增殖,减少内皮细胞u-PA的表达,这可能是其抑制血管生成的主要机制之一。     

胶质瘤细胞和血管内皮细胞相互作用对整合素αv表达的影响

背景与目的:研究表明整合素αv亚基与胶质瘤生物学行为密切相关。本研究探讨胶质瘤细胞和内皮细胞相互作用对整合素αv亚基表达的影响。方法:利用Transwell共培养系统在体外对C6胶质瘤细胞和人脐静脉内皮细胞进行共培养,通过半定量RT-PCR方法检测单独培养和共培养后的C6细胞和人脐静脉内皮细胞上整合素αv的mRNA转录的情况,细胞免疫化学方法检测单独培养和共培养后的C6细胞和人脐静脉内皮细胞上整合素αv的表达的情况。结果:经共培养后的C6细胞和人脐静脉内皮细胞上整合素αv的mRNA转录出现上调(P<0.01;P﹤0.05)和免疫染色强度也出现加强。结论:胶质瘤细胞和血管内皮细胞的相互作用可诱导整合素αv表达的上调。     

腹膜间皮细胞对卵巢癌细胞血管生成因子表达及分泌的影响

目的探讨腹膜间皮细胞（HPMC）对卵巢癌细胞血管生成因子表达及分泌的影响。方法用ELISA法检测HPMC条件培养液中肿瘤坏死因子α（TNF—α）及白介素-1β（IL-1β）的水平。用培养小室Millicell将卵巢癌细胞SKOV3与HPMC在不同培养条件下进行共培养。用RT—PCR方法检测SKOV3血管内皮生长因子（VEGF）和碱性成纤维细胞生长因子（bFGF）的基因表达,ELISA法检测SKOV3条件培养液中VEGF和bFGF的蛋白水平。结果HPMC条件培养液中可检测到TNF—α和IL-1β。SKOV3与HPMC共培养后,其VEGF和bFGFmRNA表达增强,条件培养液中VEGF和bFGF蛋白水平升高,与SKOV3单独培养相比,差异均有统计学意义（P〈0．01）。加入TNF—α或IL-1β的中和抗体共培养,可明显抑制SKOV3VEGF及bFGFmRNA表达及蛋白分泌（P〈0．01）,共培养体系中同时加入TNF—α中和抗体及IL-1β中和抗体时,抑制作用增强（P〈0．05）。结论HPMC分泌TNF—α和IL-1β,刺激卵巢癌细胞表达及分泌更高的VEGF和bFGF,参与卵巢癌的血管生成及腹膜转移。     

双调蛋白反义核酸表达对裸鼠乳腺癌血管生成的抑制作用

目的 研究双调蛋白（AR）反义RNA表达对乳腺癌血管生成的抑制作用。方法 乳腺癌NS2T2A1细胞经AR反义cDNA质粒转染后,经筛选获得表达AR反义RNA的AR-AS1及AR-AS3克隆,转染空载体获得NS2T2A1 V对照细胞,接种裸鼠皮下形成肿瘤。研究条件培养液对人微血管内皮细胞（HMEC）增殖的影响,以EL1SA法测定细胞血管内皮生长因子（VEGF）分泌量。以定量RT-PCR分析肿瘤组织的VEGF表达水平。以免疫组化法标记CD31研究肿瘤内血管数量。结果 HMEC在AR-AS1和AR-AS3细胞条件培养液中的增殖比例明显降低。AR-AS1和AR-AS3细胞VEGF分泌量亦降低。AR-AS1和AR-AS3肿瘤的血管数量仅有对照组的50％左右,且VEGF表达显著降低。结论 AR反义RNA表达可有效抑制乳腺癌的血管生成,应作为新治疗靶点进一步研究．     

肿瘤血管生长抑制因子与肝细胞癌关系研究进展

血管生成抑制因子对于调控肿瘤的生物学行为和肿瘤的治疗方面具有重要的作用.血管生成受正、负调控因子的双重作用,目前发现的与肝细胞癌（hepatocellular carcinoma,HCC）有关的血管生成抑制因子有血管生成抑制素（AS）、内皮抑素（ES）、干扰素（IFN）、血小板反应素（TSP）、组织金属蛋白酶抑制剂（TIMP）、转化生长因子β1（TGFβ1）、白细胞介素12（IL 12）、肿瘤坏死因子（TNF）、血小板因子4（PE4）及纤溶酶原抑制因子（PAI）等.其作用机制为：抑制内皮细胞的分裂和迁移,降低内皮细胞的活性,促进内皮细胞的凋亡或直接杀伤内皮细胞,干扰基底膜与内皮细胞的相互作用,抑制蛋白水解反应和内皮细胞的黏附运动,下调各种促血管生成因子的表达等.这些因子具有抗HCC血管生成治疗药物的潜在意义.     

肿瘤血管生长抑制因子与肝细胞癌关系研究进展

血管生成抑制因子对于调控肿瘤的生物学行为和肿瘤的治疗方面具有重要的作用。血管生成受正、负调控因子的双重作用,目前发现的与肝细胞癌(hepatocellularcarcinoma,HCC)有关的血管生成抑制因子有血管生成抑制素(AS)、内皮抑素(ES)、干扰素(IFN)、血小板反应素(TSP)、组织金属蛋白酶抑制剂(TIMP)、转化生长因子β1(TGFβ1)、白细胞介素12(IL12)、肿瘤坏死因子(TNF)、血小板因子4(PE4)及纤溶酶原抑制因子(PAI)等。其作用机制为:抑制内皮细胞的分裂和迁移,降低内皮细胞的活性,促进内皮细胞的凋亡或直接杀伤内皮细胞,干扰基底膜与内皮细胞的相互作用,抑制蛋白水解反应和内皮细胞的黏附运动,下调各种促血管生成因子的表达等。这些因子具有抗HCC血管生成治疗药物的潜在意义。     

人参皂苷Rg3抑制B16黑色素瘤新生血管生成及其机制的探讨

目的:观察20(S)-人参皂苷Rg3(SPG-Rg3)对B16黑色素瘤血管生成的影响,并探讨其可能的作用机制.方法:体内采用肿瘤诱导血管生成实验,观察SPG-Rg3对B16黑色素瘤血管生成的影响;免疫细胞化学法观察SPG-Rg3对B16黑色素瘤细胞血管内皮细胞生长因子(VEGF)表达的影响;取不同浓度SPG-Rg3作用后的B16黑色素瘤细胞条件培养基(BMCM)作用于人脐静脉内皮细胞,用MTT法、PCNA免疫荧光染色以及迁移实验观察SPG-Rg3对内皮细胞增殖和迁移的作用.结果:在肿瘤诱导血管生成实验中,SPG-Rg3组肿瘤周围的血管数明显少于对照组,P＜0.01;SPG-Rg3作用组BMCM的促内皮细胞增殖和迁移作用均明显弱于无SPG-Rg3作用组,且SPG-Rg3(5 μg/mL)降低了B16黑色素瘤细胞VEGF的表达,P＜0.01.结论:SPG-Rg3可明显抑制B16黑色素瘤的血管生成,且可能通过降低肿瘤细胞分泌VEGF来抑制肿瘤细胞对血管内皮细胞增殖和迁移的促进作用,从而达到抑制肿瘤新生血管形成的作用.     

RhoC 过表达对人脐静脉内皮细胞体外迁移 及血管生成能力的影响

 目的　探讨RhoC 基因过量表达对内皮细胞体外迁移及血管生成过程的影响。方法　构建 RhoC 真核表达载体,以脂质体转染人脐静脉内皮细胞( HUVE) ,采用RT2PCR 和Western blot 检测 RhoC 的mRNA 及蛋白表达水平; 划痕实验检测细胞迁移能力; 胶原基质胶三维培养检测内皮细胞体 外血管生成能力。结果　转染RhoC 实验组与空载体对照组比较,RhoC mRNA 和蛋白表达明显增高; 细胞迁移能力和血管样结构生成能力明显增强。结论　RhoC 高表达能促进人脐静脉内皮细胞体外迁 移及血管生成。     

Tumor cell-tumor endothelial cell adhesion mediated by alphavbeta3 and alphavbeta5 molecules

OBJECTIVE: To investigate the role of adhesion molecules alphavbeta3 and alphavbeta5 and their ligands Del-1 and L1 in the tumor-endothelial cell adhesion in vitro. METHODS: The expression of alphavbeta3, alphavbeta5 and ICAM-1 in liver sinusoidal endothelial cells (LSEC) and liver cancer endothelial cells (T3A) cultured under normoxia or hypoxia were analyzed by RT-PCR and fluorescent activated cell sorter (FACS). The expression of Del-1 and L1 in six tumor cell lines under normoxia or hypoxia were analyzed by RT-PCR and Western blot, respectively. The adhesion of dye-labeled tumor cells and endothelial LSEC and T3A cells was measured by a fluorescence plate reader after their culture. RESULTS: The expression of alphavbeta3 and alphavbeta5 were higher in T3A cells than that in LSEC cells, and were upregulated under hypoxia, while the expression of ICAM-1 was lower in T3A cells than that in LSEC cells, and was upregulated under hypoxia only in LSEC. The expression of Del-1 and L1 molecules were obviously different in various tumor cell lines and were differentially regulated under hypoxia. The adhesion of tumor cells with Del-1 or L1 expression was higher in T3A cells than that in LSEC cells, and was significantly increased under hypoxia condition. Furthermore, the adhesion of tumor cells to T3A could be inhibited by antibodies against alphavbeta3 and alphavbeta5, or SiRNAs for beta3 and beta5. CONCLUSION: alphavbeta3 and alphavbeta5 and their ligands Del-1 and L1 may play an important role in tumor cell migration.     

Plasminogen activator mediated degradation of subendothelial extracellular matrix by human squamous carcinoma cell lines

Extracellular matrix (ECM) produced by bovine corneal endothelial cells was used to investigate the role of the plasminogen activator/plasmin system in the degradation of ECM by human squamous cell carcinoma (SqCCs) and human foreskin epidermal cells (HFEC). SqCCs caused an 8- to 34-fold greater solubilization of 3H-glucosamine-labeled ECM than HFEC. This action in SqCCs was dependent upon the presence of acid-treated serum, indicating that tumor-associated proteinases were sensitive to the inhibitory action of acid-labile proteinase inhibitors present in the serum. SqCC mediated digestion of radiolabeled ECM was decreased by 14- to 55-fold in plasminogen depleted serum, and the addition of 100 micrograms/mL of purified human plasminogen resulted in up to a 30-fold increase in the degradation of the ECM. Inhibitors of this proteinase system and murine monoclonal antibodies (MAb) specific for human urokinase plasminogen activator (uPA) decreased the SqCC mediated digestion of radiolabeled ECM in a concentration dependent manner. SqCCs exhibited 10- to 30-fold higher extracellular uPA levels than HFEC, as assayed by substrate hydrolysis, zymography, micro-ELISA, western analysis, and northern analysis. These findings reflect the differential ability of these cell types to degrade the ECM. In addition, immuno-cross-reactive plasminogen activator inhibitor type I (PAI type 1) and type II (PAI type 2) were identified in cell-free conditioned medium produced by both tumor cells and normal epidermal cells, using a micro-ELISA assay. Indirect immunofluorescence flow cytometry, employing MAbs directed against uPA, detected the presence and localization of uPA on the SqCC cell surface. These findings were specific for uPA, since cell surface associated tissue plasminogen activator was not detected in these cell types under analogous conditions. In addition, partially purified SqCC plasma membrane preparations exhibited 2- to 10-fold higher uPA-like activity than HFEC, as determined by zymography. The findings support the concept that the plasminogen activator system is important in the breakdown of ECM by SqCCs and suggest that regulatory mechanisms involved in this proteolytic system may be important targets for chemotherapeutic intervention to limit tumor cell invasion and metastasis.     

Modulation of Tissue-type Plasminogen Activator Expression by Platelet Activating Factor in Human Glioma Cells

Purpose. For tumor growth, proteolytic remodeling of the extracellular matrix (ECM) is a key factor. To determine proteolytic activity in human glioma cells, fibrinolytic activity, mRNA expression of fibrinolytic factors, and fibrinolytic inhibitors were studied in human glioma cell lines. The effect of platelet activating factor (PAF), a potent mediator of inflammatory and immune responses, on this fibrinolytic activity was also examined. Methods. The fibrinolytic activities of conditioned medium and cell lysates from human glioma cell lines, A172, T98G, U87 and TM1 were studied by fibrin plate zymography. mRNA expression of tissue plasminogen activator (tPA), urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitors (PAI-1, PAI-2) was measured by Northern blot analysis. PAF was added to the medium, and its effects on cell proliferation, fibrinolytic activity, mRNA expression of plasminogens and inhibitors were studied. Results. mRNA expression of plasminogens and inhibitors differed between individual cell lines. Only the medium and cell lysates from A172 cells revealed fibrinolytic activity. A172 cells showed mRNA expression of tPA. PAF at low concentrations, such as 1 nM, stimulated A172 cell proliferation, and high concentrations of PAF inhibited proliferation. PAF stimulated tPA release into the conditioned medium. mRNA expression of tPA was stimulated by low concentrations of PAF and inhibited by high concentrations. Conclusion. The variability of mRNA expression of plasminogen activators (PAs) between different glioma cell lines may indicate that plasminogens and their inhibitors do not directly correlate with brain tumor growth. PAF may be an important factor in the local control of fibrinolytic activity in glioma and its proliferation.     

Effect of retinoic acid on human neuroblastoma: Correlation between morphological differentiation and changes in plasminogen activator and inhibitor activity

Summary The relationship between plasminogen activator (PA)/plasminogen activator inhibitor (PAI) activity and morphological differentiation was investigated in human neuroblastoma (NB) cells treated with retinoic acid (RA). Conditioned medium from nine NB cell lines and one closely related neuroepithelioma line was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and zymography. All NB cell lines were shown to secrete urokinase (UK)-type PA (mol. wt., 52 kDa), and all except two produced tissue PA (mol. wt., 65 kDa). Identification of the PAs was made based on molecular weight and sensitivity to inhibition by anti-UK and anti-tPA antibodies. Several cell lines expressed PA inhibitory molecules; two molecular-weight forms were observed (35 and 40 kDa) in different cell lines. Complex formation with^[125]I-labelled proteases revealed specific binding with UK and trypsin but not thrombin, plasmin, or kallikrein. After treatment for 6 days with 1 M RA, six of the cell lines exhibited an increase in cell-associated and/or secreted tPA activity, corresponding to morphological differentiation of the cells as manifested by extensive neurite outgrowth. A decrease in UK and UK-complex secretion was observed in several of these cell lines. Three cell lines exhibiting no detectable morphological alterations with RA treatment also showed no dramatic changes in PA/PAI activity. These results suggest that morphological differentiation of NB cells may be associated with alterations in the regulation of PA activity.Abbreviations NB neuroblastoma - RA retinoic acid - PA plasminogen activator - PAI plasminogen activator inhibitor - SDS sodium dodecyl sulfate - UK urokinase - tPA tissue plasminogen activator     

成年人脂肪源间充质干细胞治疗急性移植物抗宿主病后CD+8 T细胞亚群的变化

  目的 初步探讨成年人脂肪源间充质干细胞（AMSC）治疗急性移植物抗宿主病（aGVHD）的分子机制。方法 3例行异基因造血干细胞移植术后发生aGVHD的患者,以每1 kg体重2×106个细胞剂量静脉输注AMSC;首先应用尼龙毛柱分离外周血T淋巴细胞,再经CD8磁珠分选出CD+8 T淋巴细胞,应用流式细胞术检测发生aGVHD患者使用AMSC前后外周血CD+8 T细胞亚群的变化。结果 与输注AMSC前相比,输注AMSC后,CD+8 T细胞中的CD+8 CD-28亚群显著上调,同时,患者的aGVHD得以有效控制。结论 AMSC治疗aGVHD的作用机制可能与其上调CD+8 CD-28 T细胞亚群有关,CD+8 T细胞可能是AMSC作用的靶细胞。     

Characterization of Matrix-degrading Proteinases and Their Inhibitors Secreted by Human Gynecological Carcinoma Cells

Matrix-degrading proteinases secreted by tumor cells play crucial roles in tumor cell invasion and metastasis. Serum-free conditioned media of 7 human gynecological carcinoma cell lines were examined for proteinases and their inhibitors by using gelatin zymography, reverse zymograpby and immunoblotting. All of three ovarian adenocarcinoma cell lines secreted urokinase-type plasminogen activator. Among them, a mucinous cystadenocarcinoma cell line also secreted tissue-type plasminogen activator, plasmin-like enzyme and trypsinogen. On the other hand, two ovarian undifferentiated carcinoma cell lines mainly secreted gelatinase A or B. A choriocarcinoma cell line secreted multiple metalloproteinases in the highest amount, whereas an endometrial adenocarcinoma cell line (HEC-1) derived from an early clinical stage hardly secreted any gelatinolytic enzyme. The five high proteinases producers hardly secreted the corresponding inhibitors, such as tissue inhibitor of metalloproteinases (TIMP)-1,-2 or plasminogen activator inhibitor-1. In contrast to these highly malignant cell lines, a poor proteinase producer, HEC-1, secreted a large amount of TIMPs. Therefore, an enhanced proteolytic tendency appears to be associated with gynecological cancer cells established from highly malignant tumors.     

A distinct subpopulation within CD133 positive brain tumor cells shares characteristics with endothelial progenitor cells

The cell surface marker CD133 has been proposed as a brain tumor stem cell marker. However, there have been substantial controversies regarding the necessity and role of CD133 in tumorigenesis. This study aimed to characterize CD133(+) cells in brain tumors. Human brain tumor specimens and whole blood were collected from the same patients (N=12). We carried out dual FACS staining for CD133/CD34 and functional tumorigenesis and angiogenesis analyses of CD133(+) cells from different origins. We also investigated the in vivo tumorigenic potential and histological characteristics of four distinct groups on the basis of expression of CD133/CD34 markers (CD133(+), CD133(+)/CD34(+), CD133(+)/CD34(-), and CD133(-)). CD133(+) brain tumor cells coexpressed significantly higher positivity for CD34 (70.7±5.2% in CD133(+) vs. 12.3±4.2% in CD133(-) cells, P<0.001). CD133(+) brain tumor cells formed neurosphere-like spheroids and differentiated into multiple nervous system lineages unlike CD133(+) blood cells. They showed biological characteristics of endothelial cells, including vWF expression, LDL uptake and tube formation in vitro, unlike CD133(-) brain tumors cells. Pathologic analysis of brains implanted with CD133(+) cells showed large, markedly hypervascular tumors with well-demarcated boundary. CD133(+)/CD34(-) cells produced smaller but highly infiltrative tumors. Notably, pure angiogenic cell fractions (CD133(+)/CD34(+)) and CD133(-) tumor cells did not generate tumors in vivo. Our data suggest the presence of a distinct subpopulation of CD133(+) cells isolated from human brain tumors, with characteristics of endothelial progenitor cells (EPCs).     

Induction of tissue-type plasminogen activator and 72-kDa type-IV collagenase by ionizing radiation in rat astrocytes

Radiation-induced damage in the central nervous system (CNS) is believed to be targeted to glial or endothelial cells or both, although the pathophysiology of the process is still poorly understood. In this study, we irradiated rat astrocytes with single doses of X-rays and then estimated the levels of tissue plasminogen activator (tPA) and collagenase in serum-free medium and cell extracts at different times. Fibrin zymography revealed increased levels of intracellular tPA activity at 12 hr after irradiation. Gelatin zymography showed continuously increasing levels of extracellular 72-kDa type-IV collagenase after irradiation. Quantitative enzymatic activities by densitometry showed a 3-to 4-fold elevation in the level of the intracellular tPA activity at 12 hr and a 5-to 6-fold increase in the level of the extracellular 72-kDa type-IV collagenase activity at 48 hr. An ELISA with specific antibodies for tPA and 72-kDa type-IV collagenase indicated a 5-fold increase in the level of tPA at 12 hr and a more-than-7-fold increase in the level of 72-kDa type-IV collagenase at 48 hr. This study adds considerable credibility to the proposed role of plasminogen activators and type-IV collagenase in the development of CNS damage after radiotherapy for brain tumors.