紫杉醇抗血管生成作用的实验研究

 目的　探讨紫杉醇的抗血管生成作用。方法　以人脐静脉内皮细胞 (HUVEC)原代培养模型 ,MTT法测定紫杉醇对HUVEC增殖的影响 ;采用鸡胚尿囊膜血管形成模型 (CAM模型 ) ,观察紫杉醇对鸡胚尿囊膜新生血管的抑制作用。结果　紫杉醇在非细胞毒浓度下可在体外抑制HUVEC的增殖 ,在体内抑制鸡胚尿囊膜新生血管形成。结论　紫杉醇在非细胞毒浓度下具有抗血管生成作用。     

长春瑞滨及联合热疗抗血管生成作用的实验

目的探讨长春瑞滨及联合热疗对血管生成的抑制作用。方法以人肺癌A549细胞为对照,采用MTT法观察长春瑞滨及联合热疗对人脐静脉内皮细胞（HUVEC）增殖的影响;通过Transwell趋化实验、小管形成实验及流式细胞术观察长春瑞滨对HUVEC迁移、小管形成及细胞凋亡的影响;利用鸡胚绒毛尿囊膜（CAM）模型,观察长春瑞滨对体内CAM新生血管的影响。结果小剂量（0.1～1 ng/ml）长春瑞滨对HUVEC和A549增殖抑制具有差异细胞毒性（P=0.000）。0.1～1 ng/ml 长春瑞滨呈剂量依赖性抑制HUVEC增殖（r=0.993,P=0.000）,联合热疗具有抑制HUVEC增殖的叠加或协同效应。小剂量长春瑞滨能够抑制HUVEC迁移和小管形成,诱导HUVEC凋亡,遏制CAM新生血管形成。结论小剂量长春瑞滨具有抗血管生成作用,联合热疗具有协同或叠加效应。     

雷公藤红素抑制血管内皮细胞株增殖的体外研究

目的探讨雷公藤红素抑制血管内皮细胞体外增殖的机理。方法通过生长曲线、HE染色以及流式细胞仪分析雷公藤红素抑制血管内皮细胞株ECV304体外增殖状况。结果在体外雷公藤红素能够明显抑制内皮细胞株ECV304增殖,低浓度(5μg/ml、10μg/ml和15μg/ml)的雷公藤红素主要引起血管内皮细胞S期受阻,高浓度(20μg/ml)同时还表现为细胞毒作用,引起血管内皮细胞坏死。结论雷公藤红素通过阻碍DNA合成及细胞毒作用抑制血管内皮细胞的体外增殖。     

参麦注射液联合环磷酰胺抑制血管生成作用的实验研究

目的:探讨参麦注射液联合应用环磷酰胺对体内外血管生成的抑制作用。方法:以人肝癌细胞HepGⅡ作为对照,分别采用MTT法、三维血管模型、鸡胚尿囊膜(CAM)模型观察参麦注射液联合环磷酰胺对体外人微血管内皮细胞(HMVEC)增殖、迁移和体内血管生成的影响。结果:40μl/ml参麦注射液和0.4mg/ml环磷酰胺对血管内皮细胞增殖的抑制率分别为18%、11.2%,联合应用为39.1%;而对HepG II增殖的抑制率仅分别为1.2%、3.6%,联合应用为11.8%;对血管内皮细胞有抑制出芽的作用,联合应用具有显著的协同效应。对鸡胚尿囊膜新生血管生成具有协同抑制作用。结论:小剂量参麦注射液(40μl/ml)、环磷酰胺(0.4mg/ml):在体内外具有抑制血管生成作用,而对肝癌细胞无明显抑制作用;在体外具有抑制血管增殖和迁移的协同作用和体内具有抑制血管生成协同作用。     

人血管抑制因子Vasostatin短片段（120 180 aa）的克隆、表达及功能研究

目的：利用基因工程技术，克隆并表达人血管抑制因子Vasostatin120180 aa功能区片段，探讨其对鸡胚绒毛尿囊膜新生血管抑制的作用。方法：采用PCR技术扩增人血管抑制因子Vasostatin120180 aa功能区基因，并利用pQE30原核表达系统诱导表达Vasostatin120180aa，经镍金属螯合层析法纯化，通过鸡胚绒毛尿囊膜实验验证其抑制新生血管生成的作用。结果：PCR扩增出了长度为180 bp的Vasostatin120180 aa功能区基因，后经pQE30原核表达系统表达并纯化出Vasostatin120180 aa，SDSPAGE显现一条约8 kD的阳性条带，Vasostatin120180aa可显著抑制鸡胚绒毛尿囊膜新生血管的生成。结论：原核表达的Vasostatin120180 aa功能区片段具有生物学活性，可明显抑制鸡胚绒毛尿囊膜新生血管的生成，在一定范围内呈量效依赖性。     

羟喜树碱联合热疗对体内外血管生成的抑制作用

目的:探讨羟喜树碱联合应用热疗(thermotherapy)对体内外血管生成的抑制作用。方法:采用MTT法观察羟喜树碱联合热疗对人微血管内皮细胞(HMVEC)、人肝癌细胞HepGⅡ增殖的影响。利用三维血管模型观察羟基喜树碱联合热疗对HMVEC迁移的影响。利用鸡胚绒毛尿囊膜(CAM)模型,观察羟喜树碱对鸡胚绒毛尿囊膜血管生成的影响。结果:羟喜树碱在20~40ng/ml、5~80ng/ml浓度范围内,具有抑制血管内皮细胞增殖和迁移作用,内皮细胞存活率(68.2%~44.7%),均与浓度呈负相关(相关系数r分别为-0.906、-0.469,P值分别为0.00003、0.0051);具有抑制鸡胚绒毛尿囊膜血管生成的作用;而在5~80ng/ml浓度范围内,对人肝癌细胞无细胞毒作用(细胞存活率:100%~90%)。20ng/ml的羟喜树碱与热疗联合应用在体外具有抗血管生成的协同效应;40ng/ml的羟喜树碱与热疗联合应用在体外具有抗血管生成的次加效应。结论:小剂量羟喜树碱(20~40ng/ml)联合热疗在体内外均具有抑制血管增殖和迁移协同或次加作用。     

人血管抑制因子Vasostatin短片段(120-180 aa)的克隆、表达及功能研究

目的:利用基因工程技术,克隆并表达人血管抑制因子Vasostatin120-180aa功能区片段,探讨其对鸡胚绒毛尿囊膜新生血管抑制的作用.方法:采用PCR技术扩增人血管抑制因子Vasostatin120-180aa功能区基因,并利用pQE30原核表达系统诱导表达Vasostatin120-180aa,经镍金属螯合层析法纯化,通过鸡胚绒毛尿囊膜实验验证其抑制新生血管生成的作用.结果:PCR扩增出了长度为180 bp的Vasostatin120-180aa功能区基因,后经pQE30原核表达系统表达并纯化出Vasostatin120-180aa,SDS-PAGE显现一条约8 kD的阳性条带,Vasostatin120-180aa可显著抑制鸡胚绒毛尿囊膜新生血管的生成.结论:原核表达的Vasosta-tin120-180aa功能区片段具有生物学活性,可明显抑制鸡胚绒毛尿囊膜新生血管的生成,在一定范围内呈量效依赖性.     

重组人血管内皮抑制素抑制内皮细胞血管生成的实验研究

目的:观察国产重组人血管内皮抑制素(Endostar,恩度)对人脐静脉内皮细胞(HUVECs)的抗血管生成作用,并对其机制进行初步探讨.方法:采用MTS/PMS系统测定不同浓度恩度对HUVECs和人肝癌细胞株HepG2的生长抑制作用;流式细胞术检测恩度在相同时间内诱导HUVECs和HepG2细胞早期凋亡和晚期凋亡情况;通过迁移/侵袭实验、体外管腔形成实验和鸡胚尿囊膜(CAM)实验观察恩度对HUVECs迁移/侵袭和体内外管腔形成及功能的影响.结果:不同浓度的恩度持续作用72h,对HUVECs具有抑制增殖,且在50～200ng/ml的剂量范围内呈现浓度依赖关系;而对HepG2细胞未见明显作用.药物处理方式的不同,恩度对HUVECs诱导凋亡和迁移/侵袭作用差异显著;对HepG2细胞的迁移/侵袭未见明显影响.高剂量的恩度对HUVECs体外管腔形成和鸡胚尿囊膜的血管发生及成熟具有显著影响.结论:重组人血管内皮抑制素(恩度)能够有效地抑制血管内皮细胞形成复杂的管腔,并显著影响血管的成熟;对人肝癌细胞系HepG2生长及迁移/侵袭未见明显影响.     

参麦注射液联合热疗抑制血管生成作用的体内外实验研究

目的探讨参麦注射液联合应用热疗对体内外血管生成的抑制作用。方法采用MTT法观察参麦注射液联合热疗对人微血管内皮细胞(HMVEC)、人肝癌细胞HepGⅡ增殖的影响。利用三维血管模型观察参麦注射液联合热疗对HMVEC迁移的影响。利用鸡胚绒毛尿囊膜(CAM)模型,观察参麦注射液对鸡胚绒毛尿囊膜血管生成的影响。结果参麦注射液在40μl/ml~160μl/ml浓度范围内,具有抑制血管内皮细胞增殖和迁移作用(内皮细胞存活率在82.0%~36.8%),均与浓度呈负相关(相关系数分别为-0.949、-0.535,P值分别为0.0012、0.0043);具有抑制鸡胚绒毛尿囊膜血管生成的作用;而在40μl/ml~80μl/ml浓度范围内时,对人肝癌HepGⅡ细胞表现出亚细胞毒作用(细胞存活率在98.8%~76.2%之间);当浓度≥160μl/ml时对人肝癌HepGⅡ细胞发挥细胞毒作用,(细胞存活率低于50%)。40μl/ml~160μl/ml的参麦注射液与热疗联合应用在体外具有抗血管生成的协同效应。结论小剂量参麦注射液(40μl/ml~160μl/ml)联合热疗在体内外均具有抑制血管增殖和迁移协同作用。     

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。     

EGCG对肿瘤生物抑制机制影响的探讨

目的:探讨表没食子儿茶素没食子酸酯(EGCG)通过抑制血管内皮生长因子(VEGF)的血管生成效应减少肿瘤生长和血管生成。方法:MTT法检测内皮细胞生长、Transwell检测内皮细胞迁移,同时检测内皮细胞体外小管形成情况及Matrigel胶塞体内实验检测体内血管生成情况;建立异位胃癌裸鼠模型,检测肿瘤生长及肿瘤组织微血管密度,明确EGCG对肿瘤生长和血管生成的抑制作用及其机制。结果:体外实验显示,随着EGCG处理时间和剂量的增加,VEGF诱导生长的内皮细胞数呈时间和剂量依赖性地减少;随着EGCG剂量的增加,VEGF诱导迁移的内皮细胞数和形成的小管样结构也剂量依赖性地减少,差异有统计学意义,P<0.05;Matrigel胶塞体内实验也显示EGCG抑制VEGF诱导的胶塞血管化;动物实验显示治疗组肿瘤生长缓慢,生长曲线明显低于对照组,平均肿瘤抑制率为60.4%,P<0.01;治疗组肿瘤组织微血管密度显著降低,P<0.01。结论:EGCG可以抑制VEGF诱导的血管生成,从而抑制肿瘤生长和血管生成。     

重组人血管内皮抑素对血管新生的影响研究

目的 探讨重组人血管内皮抑素（Endostar,恩度）对血管内皮细胞趋化、迁移、粘附、增殖及小管形成等与血管新生相关生物学行为的影响。方法 以原代培养的人脐静脉内皮细胞（HUVEC）为细胞模型,通过Boyden小室荧光定量分析、划痕试验、HUVEC荧光定量粘附分析、CFSE染色流式细胞术、CCK-8定量检测、小管形成试验和Matrigel栓试验研究恩度对HUVEC与血管新生相关的生物学行为的影响。结果 恩度在5～50 000ng／ml范围内可抑制血管内皮生长因子诱导HUVEC的迁移运动,且浓度为50ng／ml和500ng／ml时效果最明显;恩度在5～50 000ng／ml间可呈剂量依赖的方式抑制HUVEC向损伤部位的迁移。与0ng／ml相比,50、500和5000ng／ml 恩度处理的HUVEC的粘附率、增殖率及HUVEC形成网状小管结构的数量、面积和长度均降低,差异均有统计学意义（P＜0.05）; Matrigel栓实验结果显示,恩度在50～5000ng／ml间对SCID小鼠体内血管新生有明显的抑制作用。结论 恩度在细胞水平能抑制HUVEC与血管新生相关的生物学行为,包括HUVEC的趋化、迁移、粘附、增殖和小管形成;在动物水平能抑制SCID小鼠体内的血管新生,据此推断恩度能抑制血管新生。     

Clotrimazole, an Imidazole Antimycotic, Is a Potent Inhibitor of Angiogenesis

Clotrimazole, an imidazole antimycotic, interferes with the rise in cytosolic Ca²⁺ and inhibits cell proliferation in a reversible manner. Here we describe the effect of clotrimazole on vascular endothelial cells (ECs). Clotrimazole inhibited the proliferation of ECs stimulated with typical angiogenic growth factors; vascular endothelial growth factor and basic fibroblast growth factor (bFGF). This inhibitory effect of clotrimazole was dose-dependent and the maximal inhibition was observed at a concentration of 10 m M . We did not observe any increase in ⁵¹Cr release from ECs during treatment with 10 μ M . clotrimazole. Moreover, clotrimazole inhibited the basal and bFGF-stimulated migration of ECs. As clotrimazole inhibited two principle components of angiogenesis; the proliferation and migration of ECs, we examined whether clotrimazole inhibited angiogenesis. Tube formation by ECs in type 1 collagen gel was investigated, and clotrimazole was found to be significantly inhibitory. The inhibitory effect of clotrimazole on angiogenesis was further confirmed in an in vivo angiogenesis model of murine Matrigel plug assay. These results demonstrate that clotrimazole is a potent inhibitor of angiogenesis.     

Angiogenic activity of pyruvic acid in in vivo and in vitro angiogenesis models

The excessive growth of a tumor requires high rates of glucose uptake and glycolysis and continuous recruitment of new blood vessels. Here, we provide several lines of evidence showing that pyruvic acid, the end product of glycolysis, exhibits strong angiogenic activity. Pyruvic acid promoted angiogenesis in chorioallantoic membrane assay and in vivo mouse Matrigel plug assay. Pyruvic acid also positively affects angiogenic cascade, DNA synthesis, migration, and tube formation in bovine aortic endothelial cells. Furthermore, mRNA expression of fibroblast growth factor receptor-2 and vascular endothelial growth factor was enhanced by pyruvic acid. These results strongly suggest that pyruvic acid plays an important role in angiogenesis for tumor growth and metastasis.     

The antiangiogenic property of docetaxel is synergistic with a recombinant humanized monoclonal antibody against vascular endothelial growth factor or 2-methoxyestradiol but antagonized by endothelial growth factors

Numerous chemotherapeutic agents have been shown to have an inhibitory effect on endothelial cell proliferation and migration, and tubule formation. In this study, we examined the antiangiogenic activity of docetaxel. Docetaxel inhibited endothelial cell proliferation and tubule formation in vitro in a dose-dependent fashion. Docetaxel treatment also inhibited angiogenesis in an in vivo Matrigel plug assay. The endothelial stimulating factors, vascular endothelial cell growth factor (VEGF) and basic fibroblast growth factor are able to protect endothelial cells from the antiangiogenic properties of docetaxel. This protective effect can be overcome by a recombinant humanized monoclonal antibody directed against VEGF in both in vitro and in vivo models. Similarly, combination of docetaxel with the antiangiogenic agent 2-methoxyestradiol also overcomes the protective effect of VEGF in both in vitro and in vivo models. These data suggest that microenvironmental factors (e.g., local release of VEGF and basic fibroblast growth factor) could play a role in decreasing the antiangiogenic effects of docetaxel, whereas agents such as 2- methoxyestradiol and recombinant humanized monoclonal antibody directed against VEGF may reverse this protective effect.     

Anti-angiogenic activity of inositol hexaphosphate (IP6)

A significant anticancer activity of the naturally occurring carbohydrate inositol hexaphosphate (IP(6)) has been reported against numerous cancer models. Since tumors require angiogenesis for growth and metastasis, we hypothesize that IP(6) reduces tumor growth by inhibiting angiogenesis. Because angiogenesis depends on the interaction between endothelial and tumor cells, we investigated the effect of IP(6) on both. IP(6) inhibited the proliferation and induced the differentiation of endothelial cells in vitro; the growth of bovine aortic endothelial cells (BAECs) evaluated by MTT proliferation assay was inhibited in a dose-dependent manner (IC(50) = 0.74 mM). The combination of IP(6) and vasostatin, a calreticulin fragment with anti-angiogenic activity, was synergistically superior in growth inhibition than either compound. IP(6) inhibited human umbilical vein endothelial cell (HUVEC) tube formation (in vitro capillary differentiation) on a reconstituted extracellular matrix, Matrigel, and disrupted pre-formed tubes. IP(6) significantly reduced basic fibroblast growth factor (bFGF)-induced vessel formation (P < 0.01) in vivo in Matrigel plug assay. Exposure of HepG2, a human hepatoma cell line, to IP(6) for 8 h, resulted in a dose-dependent decrease in the mRNA levels of vascular endothelial growth factor (VEGF), as assessed by RT-PCR. IP(6) treatment of HepG2 cells for 24 h also significantly reduced the VEGF protein levels in conditioned medium, in a concentration-dependent manner (P = 0.012). Thus, IP(6) has an inhibitory effect on induced angiogenesis.     

Inhibition of tumor metastasis by sodium caffeate and its effect on angiogenesis

OBJECTIVE: Sodium caffeate (SC), the sodium salt of caffeic acid, was synthesized in our laboratory. We studied the antimetastatic effect induced by SC and its inhibition of tumor angiogenesis using various in vitro and in vivo metastasis assays. METHODS: The in vivo inhibitory effect of SC on metastasis and angiogenesis was examined in the Lewis lung carcinoma pulmonary metastasis model and chicken chorioallantoic membrane (CAM) model, respectively. MTT assay and flow cytometry were used to measure the inhibition by SC of the proliferation of transformed human umbilical vein endothelial cells (ECV304) and the apoptosis induced by SC in ECV304 cells, respectively. A cell attachment assay was used to evaluate inhibition by SC of the adhesion activity of human high metastatic giant cell carcinoma of the lung (PG) cells. A cell invasion assay was used to evaluate the effect of SC on the ability of PG cells to cross tissue barriers. Inhibition by SC of gelatinase secretion in PG cells was determined by zymography. RESULTS: In vivo results showed that SC (1 g/kg i.p. for 14 days) inhibited pulmonary metastasis at a rate of 55%. There were no differences in animal weights among the groups. The angiogenesis of CAM was inhibited by SC (200 microg/egg) at a rate of 70%. In vitro studies showed that SC inhibited the proliferation of ECV304 cells by inducing apoptosis. SC also reduced the adhesion and invasion ability of PG cells and inhibited the secretion of MMP-2 and MMP-9 in PG cells. CONCLUSION: SC might be a potential antimetastatic agent with an antiangiogenic effect.     

Emodin inhibits vascular endothelial growth factor-A-induced angiogenesis by blocking receptor-2 (KDR/Flk-1) phosphorylation

Emodin (1,3,8-trihydroxy-6-methylanthraquinone), an active component in the root and rhizome of Rheum palmatum, is a tyrosine kinase inhibitor with a number of biological activities, including antitumor effects. Here, we examine the effects of emodin on vascular endothelial growth factor (VEGF)-A-induced angiogenesis, both in vitro and in vivo. In vitro, emodin dose-dependently inhibits proliferation, migration into the denuded area, invasion through a layer of Matrigel and tube formation of human umbilical vein endothelial cells (HUVECs) stimulated with VEGF-A. Emodin also inhibits basic fibroblast growth factor-induced proliferation and migration of HUVECs and VEGF-A-induced tube formation of human dermal microvascular endothelial cells. Specifically, emodin induces the cell cycle arrest of HUVECs in the G0/G1 phase by suppressing cyclin D1 and E expression and retinoblastoma protein phosphorylation, and suppresses Matrigel invasion by inhibiting the basal secretion of matrix metalloproteinase-2 and VEGF-A-stimulated urokinase plasminogen activator receptor expression. Additionally, emodin effectively inhibits phosphorylation of VEGF-A receptor-2 (KDR/Flk-1) and downstream effector molecules, including focal adhesion kinase, extracellular signal-regulated kinase 1/2, p38 mitogen-activated protein kinase, Akt and endothelial nitric oxide synthase. In vivo, emodin strongly suppresses neovessel formation in the chorioallantoic membrane of chick and VEGF-A-induced angiogenesis of the Matrigel plug in mice. Our data collectively demonstrate that emodin effectively inhibits VEGF-A-induced angiogenesis in vitro and in vivo. Moreover, inhibition of phosphorylation of KDR/Flk-1 and downstream effector molecules is a possible underlying mechanism of the anti-angiogenic activity of emodin. Based on these data, we propose that an interaction of emodin with KDR/Flk-1 may be involved in the inhibitory function of emodin toward VEGF-A-induced angiogenesis in vitro and responsible for its potent anti-angiogenic in vivo.     

Anti-angiogenic effects of a nutrient mixture on human umbilical vein endothelial cells

Matrix metalloproteinases (MMPs) have been recognized as key players in the degradation of the extracellular matrix (ECM) by migration and proliferation of endothelial cells and their subsequent invasion of the underlying stroma. The prevention of ECM degradation through the inhibition of MMP activity has been shown to be a promising therapeutic approach to block the invasion that occurs during angiogenesis. In previous studies, we demonstrated the anti-tumor effect of a nutrient mixture (NM) containing ascorbic acid, lysine, proline, green tea extract, arginine, N-acetyl cysteine, selenium, copper and manganese on various tumor cell lines in vivo and in vitro. The aim of the present study was to determine whether this mixture has anti-angiogenic effects on human umbilical vein endothelial cells (HUVECs). At near confluence, the HUVEC cell cultures were tested with NM at 0, 10, 50, 100, 500, and 1000 microg/ml in triplicate at each dose for proliferation, migration, MMP expression, and invasion. Cell proliferation was evaluated by MTT assay, invasion potential by Matrigel invasion, MMP expression by gelatinase zymography, and cell migration by a 2 mm-wide scratch in plates. For tube formation, HUVECs were cultured in previously polymerized Matrigel. NM inhibited HUVEC migration, MMP expression and invasion through Matrigel in a dose-dependent manner. Zymography showed a dose-dependent inhibition of MMP-2 expression with virtual total inhibition at a 500 microg/ml concentration. Invasion through Matrigel was totally inhibited at 500 microg/ml NM. NM reduced cell migration by scratch test in a dose-dependent fashion with total inhibition at a 500 microg/ml concentration. NM also inhibited the tube formation of HUVECs, but did not significantly inhibit cell proliferation. These results together with our earlier findings suggest that NM is a relatively non-toxic formulation with anti-angiogenic effects, such as inhibiting vascular tube formation and endothelial cell invasion and migration.