Antitumor activity of taspine by modulating the EGFR signaling pathway of Erk1/2 and Akt in vitro and in vivo

EGFR, as a critical signaling pathway in many human tumors, has become an important target of cancer drug design. Taspine has shown meaningful angiogenesis activity in previous studies. This paper is to investigate the antitumor action of taspine by modulating the EGFR signaling pathway. The study determined the expression of key signaling molecules of EGFR (EGFR, Akt, p-Akt, Erk, and p-Erk) by Western blot and real-time PCR and analyzed their correlations with subsequent reactions. In addition, the cell proliferation, migration, and EGF production were examined by MTT, transwell system, and ELISA. The antitumor activity in vivo was carried out by xenograft in athymic mice. The results showed that taspine could inhibit A431 and Hek293/EGFR cell proliferation and A431 cell migration as well as EGF production. Compared to the negative control, EGFR, Akt, and phosphorylation of Akt were significantly inhibited by taspine treatment in A431 and HEK293/EGFR cells. Consistent with the inhibition of Akt activity, Erk1/2 and its phosphorylation were reduced. Moreover, taspine inhibited A431 xenograft tumor growth. These results suggest that EGFR activated by EGF and its downstream signaling pathways proteins could be downregulated by taspine in a dose-dependent manner. The antitumor mechanism of taspine through the EGFR pathway lies in the ability to inhibit A431 cell proliferation and migration by reducing EGF secretion. This occurs through the repression of EGFR which mediates not only MAPK (Erk1/2) but also Akt signals.     

Inhibition of angiogenesis by a monoclonal antibody to kininogen as well as by kininostatin which block proangiogenic high molecular weight kininogen

High molecular weight kininogen (HK) exhibits two activities with respect to angiogenesis after cleavage by plasma kallikrein. Cleaved HK (HKa) and its cell-binding domain 5 (D5), kininostatin, are potent antiangiogenic polypeptides. They inhibit endothelial cell migration, proliferation and tube formation. HKa and D5 inhibit angiogenesis in the chicken chorioallantoic membrane (CAM) assay. D5 stimulates apoptosis and interferes with the cell cycle. In contrast, intact HK is proangiogenic by liberating bradykinin. A monoclonal antibody to HK can inhibit angiogenesis in the CAM assay, human colon carcinoma growing as a xenograft in nude mice, and murine hybridomas growing in syngeneic hosts. Not only are the tumors decreased in volume and weight to isotype controls but the mean vascular density is decreased. Thus, both D5 and its constituent peptide and monoclonal antibody have potential for inhibiting angiogenesis and tumor growth in human therapy.     

新生霉素抑制血管生成及其与长春新碱的协同作用

目的研究新生霉素的抑制血管生成作用及其机制。方法以鸡胚尿囊膜模型测定对血管生成的作用，并分别用MTT法、明胶酶谱法等观察新生霉素对于内皮细胞和肺癌PG细胞的影响。结果新生霉素200 μg/egg对鸡胚尿囊膜血管生成的抑制率为68.7％，且呈浓度依赖性抑制内皮细胞的增殖、运动、MMP-2分泌以及管腔的形成；新生霉素和长春新碱对血管生成及PG细胞的增殖均有明显的协同作用。结论本研究首次确定新生霉素具有抑制血管生成活性,与长春新碱联合可增强对血管生成的抑制作用。     

青蒿琥酯抑制新生血管生成的作用

目的　为研究青蒿琥酯成为抗血管生成药物的可能性 ,观察其对新生血管的影响 ,并初步探讨其机制。方法　采用鸡胚绒毛尿囊膜、大鼠主动脉环无血清培养、人脐静脉内皮细胞损伤迁移等实验 ,检测青蒿琥酯对新生血管增殖与迁移的抑制作用。结果　鸡胚绒毛尿囊膜实验表明 ,青蒿琥酯有较强的血管增殖抑制作用 ,对微血管作用强于大血管 ;大鼠主动脉环无血清培养实验表明 ,青蒿琥酯能明显推迟血管新生 ,减少新生血管数量 ;人脐静脉内皮细胞损伤迁移实验表明青蒿琥酯对内皮细胞具有增殖和迁移抑制作用。在这些体内外实验中 ,青蒿琥酯抑制血管生成作用呈剂量依赖性。结论　青蒿琥酯具有抑制新生血管生成作用 ,此作用可能与抑制血管内皮细胞迁移有关。     

Inhibition of angiogenesis by propolis

Propolis, obtained from honeybee hives, has been used in Oriental folk medicine as an anti-inflammatory, anti-carcinogenic, and immunomodulatory agent. There is considerable evidence suggesting that angiogenesis and chronic inflammation are codependent. Blockage of angiogenesis results in an anti-inflammatory effect. Ethanol (EEP) and ether extracts of propolis (REP), and caffeic acid phenethyl ester (CAPE), an active component of propolis, were examined for their anti-angiogenic activities using the chick embryo chorioallantoic membrane (CAM), and the calf pulmonary arterial endothelial (CPAE) cell proliferation, assays. The presence of EEP, REP and CAPE inhibited angiogenesis in the CAM assay and the proliferation of CPAE cells. The results suggest that anti-angiogenic activities of EEP, REP and CAPE are also responsible for their anti-inflammatory effect.     

Valproic acid inhibits angiogenesis in vitro and in vivo

Valproic acid (VPA) is a widely used antiepileptic agent that is undergoing clinical evaluation for anticancer therapy. We assessed the effects of VPA on angiogenesis in vitro and in vivo. In human umbilical vein endothelial cells, therapeutically relevant concentrations of VPA (0.25 to 1 mM) inhibited proliferation, migration, and tube formation. VPA 1 mM inhibited endothelial cell proliferation by 51 +/- 5%, migration by 86 +/- 11%, and tube formation by 82 +/- 3%. These changes were preceded by the hyperacetylation of histone H4, indicating the inhibition of histone deacetylase (HDAC), and a decreased expression of the endothelial nitric-oxide synthase (eNOS). The inhibition of endothelial cell tube formation by VPA was prevented by addition of the nitric oxide donor (Z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA NONOate). The anticonvulsive active VPA derivative 2-ethyl-4-methylpentanoic acid, which does not inhibit HDAC, did not affect endothelial cell proliferation, tube formation, or eNOS expression. VPA was also found to inhibit angiogenesis in vivo in the chicken chorioallantoic membrane assay and in a Matrigel plug assay in mice. Embryos from VPA-treated mice showed disturbed vessel formation. These results indicate that therapeutic plasma levels of VPA inhibit angiogenesis by a mechanism involving a decrease in eNOS expression preceded by HDAC inhibition.     

α-双炔失碳酯体内、外抑制血管生成(英文)

目的:研究雌激素受体部分拮抗剂α-双炔失碳酯(α-Ano)对体内、外肿瘤血管生成的抑制作用.方法:在C57BL/6小鼠中观察Lewis肺癌的生长情况,用免疫组织化学方法观察肿瘤微血管密度(MVD):在鸡胚绒毛膜尿囊膜(CAM)模型上观察药物对血管生成的影响;用台盼蓝排染法研究药物对人脐静脉内皮细胞(HUVEC)生长的作用;在体外观察了药物对HUVEC的由伤口引起的迁移和对胶原基质的粘附活性的影响;用荧光法间接测定一氧化氮(NO)水平.结果:α-Ano显著地抑制Lewis肺癌的MVD,同时抑制小鼠皮下接种的肿瘤生长,MVD的降低程度与肿瘤生长的抑制程度相关.α-ANO在CAM模型上也显示出对血管生成的抑制活性,抑制率达53％,17α-雌二醇对α-Ano抑制CAM血管生成的活性无明显拮抗作用;α-Ano对HUVEC的增殖和迁移活性有抑制作用,但对HUVEC对Ⅰ型胶原的粘附能力无明显影响.同时,α-Ano能够抑制HUVEC释放NO的水平,且具有时间和剂量依赖性.结论:α-Ano具有血管生成抑制活性,此作用是通过减少NO的释放,随后抑制内皮细胞的增殖和迁移而实现的.     

芸香宁碱抑制血管生成作用的研究

目的：研究芸香宁碱对血管生成的抑制作用,并研究其初步的作用机制。方法用人脐静脉内皮细胞（HUVEC）的生长、迁移实验及体内动物模型－鸡胚绒毛尿囊膜法（CAM 法）研究化合物的体内外抗血管生成作用;用酶联免疫吸附法检测芸香宁碱在非凋亡剂量时对肿瘤细胞培养上清液中 VEGF 蛋白分泌量的影响。结果芸香宁碱对血管内皮细胞具有优先抑制作用,对 HUVEC 的半数抑制剂量为（33．2±0．4）μmol·L －1,而对其他肿瘤细胞的 IC50值均大于这一数值;芸香宁碱在体外能够明显抑制内皮细胞的迁移和对细胞外基质黏附作用,并呈剂量依赖性,体内实验显示30μmol·L －1剂量浓度时显著抑制 CAM新生血管形成;芸香宁碱在15μmol·L －1和30μmol·L －1的浓度剂量时显著抑制人肝癌 HepG2细胞培养上清液中VEGF 蛋白的分泌,具有显著性差异。结论芸香宁碱在非凋亡浓度剂量具有抑制新生血管形成作用,其机制与抑制血管内皮细胞增殖以及抑制肿瘤细胞表达 VEGF 有关。     

二氢青蒿素抑制K562细胞血管内皮生长因子的表达

目的通过观察二氢青蒿素抑制K562细胞血管内皮生长因子(VEGF)的表达，探讨青蒿素类药物在抑制血液肿瘤血管新生方面的作用。方法运用MTT法、免疫组化分析和Western blotting分析等探讨了二氢青蒿素对K562细胞增殖以及VEGF表达方面的影响，并进一步对药物预处理后肿瘤细胞的条件培养基在促内皮细胞增殖以及促鸡胚绒毛尿囊膜(CAM)血管新生的作用进行评定。结果二氢青蒿素能有效抑制K562细胞的增殖，并显著下调K562细胞VEGF蛋白和mRNA的表达。同时,药物预处理细胞的条件培养基，其促内皮细胞增殖和促CAM血管新生的能力都有所下降，并呈药物浓度依赖性。结论二氢青蒿素能显著下调K562细胞VEGF的表达，并能抑制由其诱导的血管新生作用。     

Effect of 15-deoxyspergualin, a microbial angiogenesis inhibitor, on the biological activities of bovine vascular endothelial cells.

We found recently that 15-deoxyspergualin, an analog of spergualin, which is an antibiotic and includes a spermidine moiety in its structure, exhibits anti-angiogenic activity. We have now carried out in vitro experiments with bovine vascular endothelial cells to determine which events occurring during angiogenesis are affected by this microbial angiogenesis inhibitor. 15-Deoxyspergualin did not inhibit the production of urokinase-type plasminogen activator (u-PA) or type IV collagenase by vascular endothelial cells. The direct inhibition of u-PA activity by 15-deoxyspergualin was not observed either. The angiostatic antibiotic neither affected the migration of vascular endothelial cells nor inhibited the endothelial cell proliferation in a two-dimensional culture system. We also examined the effect of 15-deoxyspergualin on the proliferation of endothelial cells in a three-dimensional culture system involving collagen gel, in which cell growth resembles more closely the endothelial cell proliferation during in vivo angiogenesis than that in a two-dimensional culture system without collagen gel. The antibiotic inhibited cell proliferation in a dose-dependent manner, indicating that the three-dimensional culture system is useful for finding a new angiogenesis inhibitor with a different mode of action from those of angiogenesis inhibitors found by using a two-dimensional assay system; however, no cause-effect relationship has yet been established. Taken together, these results suggest the possible involvement of the inhibition of vascular endothelial cell growth by 15-deoxyspergualin in its angiogenesis-inhibitory effect. 15-Deoxyspergualin appears to be a promising candidate as an angiogenesis inhibitor for controlling aberrant angiogenic responses occurring in different states, including tumor development.(ABSTRACT TRUNCATED AT 250 WORDS)     

芪参益气滴丸促血管新生的实验观察

目的：观察芪参益气滴丸对鸡胚绒毛尿囊膜血管生成的影响,测定其对人脐静脉内皮细胞增殖的影响,探讨该药促进血管生成的可能机制。方法实验分组：生理盐水组、空白血清组、bFGF 组、芪参益气滴丸组;建立鸡胚尿囊膜（CAM）模型,计数各组 CAM 上血管数;体外培养人脐静脉内皮细胞,应用血管内皮细胞增殖实验（MTT）法测定各组 A 值。结果与生理盐水组及空白血清组比较,芪参益气滴丸组具有明显的促 CAM 血管生成作用（P ＜0．05）,并促进人脐静脉内皮细胞增殖（P ＜0．05）。结论芪参益气滴丸具有促血管生成作用,其机制可能与该药促进内皮细胞增殖有关。     

Antiproliferation in human EA.hy926 endothelial cells and inhibition of VEGF expression in PC-3 cells by topotecan

Protracted administration of topotecan (TPT), a topoisomerase I inhibitor, exhibited high anticancer efficacy both in animal models and human cancers. This phenomenon is related to the TPT-induced inhibition of angiogenesis in tumor, but the potential mechanism remains largely unknown. In the present study, we reported that TPT (1-10 microM) could inhibit angiogenesis in a dose-dependent manner in Chick embryo chorioallantoic membrane (CAM) assay. TPT showed strong inhibitory activity against proliferation on human EA.hy926 endothelial cells with an IC50 value of 0.13 microM (MTT assay), lower than that of most sensitive cancer cell lines (IC50 range, 0.17 microM to 5.1 microM). TPT could induce EA.hy926 cells undergoing apoptosis, and the percentage of apoptotic cells induced by TPT (0.05 microM-5.0 microM) were 17.9%-52.3%. The similar results were observed with AO/EB staining. Flow cytometry assay also revealed that various concentrations of TPT induced cell cycle disturbance in EA.hy926 cells. Western blotting results showed that TPT caused an obvious increase of p53 expression and a decline of ERK expression in EA.hy926 cells. In addition, the VEGF expression of PC-3 cells is inhibited by TPT in hypoxia. Altogether, inhibiting proliferation of endothelial cells and down-regulating VEGF expression in cancer cells may involve in the antiangiogenesis mechanism of TPT.     

青蒿琥酯抑制Twist1蛋白表达和血管再生以及降低口腔鳞癌细胞Tca8113转移的作用

目的 研究青蒿琥酯抑制Twist 1表达、降低口腔鳞癌细胞的转移及对血管生成的抑制作用.方法 采用50、100、150、200 μg·mL-1的青蒿琥酯体外培养的口腔鳞癌细胞,然后分别采用Western blot法、MTT法、划痕实验及流式细胞仪检测不同浓度的青蒿琥酯干预对口腔鳞癌细胞Twist1表达、增殖、迁移及凋亡的影响;采用鸡胚尿囊膜检测青蒿琥酯对鸡胚尿囊膜血管生成的影响.结果 与对照组对比,青蒿琥酯可抑制Twist1蛋白的表达、口腔鳞癌细胞的增殖和迁移,且存在时间和剂量依赖性;青蒿琥酯可引起细胞的凋亡,处理组的细胞凋亡率显著高于对照组;青蒿琥酯对鸡胚尿囊膜血管新生有一定的抑制作用(P＜0.05).结论 中药青蒿琥酯可抑制Twist 1蛋白的表达、细胞增殖、迁移,同时可有效抑制血管再生.     

革皮氏海参皂苷抑制血管新生作用

目的以革皮氏海参中分离得到的三萜皂苷ho-lothurin A1(HA)和24-dehydroechinoside A(DA)为研究对象,比较研究其抗血管新生的作用。方法采用MTT法和AO/EB染色法检测不同剂量HA和DA对人脐静脉内皮细胞(HUVEC)增殖和凋亡的影响;采用小管形成实验观察HA和DA对HUVEC分化形成小管能力的影响;细胞黏附实验比较研究HA和DA对HUVEC与肝癌细胞HepG2的黏附能力的影响;鸡胚绒毛尿囊膜(CAM)血管新生模型,观察HA和DA抑制CAM血管新生的情况。结果 HA和DA均具有抑制HUVEC增殖的活性(48 h的IC50值分别为4.80、3.82μmol.L-1),并能促进内皮细胞的凋亡;在体外能抑制内皮细胞小管形成,可抑制HUVEC与HepG2细胞间(P<0.01)的黏附,能使CAM新生血管明显减少,其中DA抑制血管新生活性优于HA。结论海参皂苷HA和DA具有抑制血管新生的作用,其活性与其结构相关。     

Identification of type 1 inosine monophosphate dehydrogenase as an antiangiogenic drug target

To rapidly discover clinically useful angiogenesis inhibitors, we created and screened a library of existing drugs for inhibition of endothelial cell proliferation. Mycophenolic acid (MPA), an immunosuppressive drug, was found to potently inhibit endothelial cell proliferation in vitro and block tumor-induced angiogenesis in vivo. Using RNA interference, we found that knockdown of one of the two known isoforms of inosine monophosphate dehydrogenase (IMPDH-1) is sufficient to cause endothelial cell cycle arrest.     

Anti-angiogenic activity of the flavonoid precursor 4-hydroxychalcone

Angiogenesis, the growth of new blood vessels, is necessary for cancerous tumors to keep growing and spreading. Suppression of abnormal angiogenesis may provide therapeutic strategies for the treatment of angiogenesis-dependent disorders. In the present study, we describe the in vitro and in vivo anti-angiogenic activities of the flavonoid precursor 4-hydroxychalcone (Q797). This chalcone (22μg/ml) suppressed several steps of angiogenesis, including endothelial cell proliferation, migration and tube formation without showing any signs of cytotoxicity. Moreover, we found a selective effect on activated endothelial cells, in particular with resting endothelial cells and the human epithelial tumor cell lines (HeLa, MCF-7, A549). In addition, Q797 was able to modulate both vascular endothelial growth factor (VEGF)- and basic fibroblast growth factor (FGF)- induced phosphorylation of extracellular signal-regulated kinase (ERK)-1/-2 and Akt kinase. It did not influence the nuclear translocation of p65 subunit of the nuclear factor-κB (NF-κB) when human endothelial cells were stimulated with tumor necrosis factor (TNF)-α. Taken together this indicates that the Q797-mediated inhibition of in vitro angiogenic features of endothelial cells is most likely caused by suppression of growth factor pathways. The potent inhibitory effect of Q797 on bFGF-driven neovascularization was also demonstrated in vivo using the chick chorioallantoic membrane (CAM) assay. In summary, this chalcone could serve as a new leading structure in the discovery of new potent synthetic angiogenesis inhibitors.     

岩藻糖基化海参硫酸软骨素抑制肿瘤血管新生作用的研究

目的从美国肉参(Isostichopus badionotus)中分离纯化岩藻糖基化海参硫酸软骨素(sea cucumber chondroitin sulfate,SC-CHS),体外研究其对肿瘤诱导血管生成的抑制作用。方法采用MTT法检测SC-CHS对95D细胞增殖活性的影响;小管形成实验研究SC-CHS对脐静脉内皮细胞(HUVEC)小管形成能力的抑制作用;采用鸡胚尿囊膜(CAM)新生血管模型,研究其对血管生成的影响;通过RT-PCR和WesternBlot法检测其对肿瘤诱导血管生成相关因子缺氧诱导因子(hypoxia inducible factor-1α,Hif-1α)和血管内皮生长因子(vascular endothelial growth factor,VEGF)mRNA和蛋白的表达。结果结果显示SC-CHS能显著抑制95D细胞的增殖,能抑制HUVEC的小管形成作用和CAM血管新生。RT-PCR和Western Blot检测结果表明,高剂量SC-CHS能显著降低95D细胞中Hif-1α和VEGF mRNA的表达,减少VEGF蛋白的合成。结论SC-CHS体外能显著抑制肿瘤血管生成,这可能是通过影响肿瘤细胞中VEGF的合成发挥作用。     

Effect of beta-escin sodium on endothelial cells proliferation, migration and apoptosis

beta-Escin, the major active compound in extracts of the horse chestnut Aesculus hippocastanum seed, has shown clinically significant activity in chronic venous insufficiency (CVI). Our previous studies had shown that beta-escin sodium inhibited angiogenesis in chick chorioallantoic membrane (CAM) and in aortic disk assay. In this study, we explored the direct effect of beta-escin sodium on proliferation, migration and apoptosis in human umbilical vein endothelial cells (HUVECs) and ECV304 cells. Sulforhodamine B (SRB) assay showed that beta-escin sodium (10, 20, 40 microg/ml) inhibited endothelial cells (ECs) proliferation dose-dependently. beta-escin sodium also induced ECs apoptosis at 40 microg/ml. Cell migration was evaluated by an improved wound assay: barren spot assay. And the direct effect on cell motility excluding influence of cell proliferation was examined by High Content Screening (HCS, Cellomics) assay. The data indicated that beta-escin sodium suppressed ECs migration and cell motility. Western blot results suggested that beta-escin sodium acts on ECs possibly by increasing expression of thrombospondin-1 (TSP-1), and decreasing expression of PKC-alpha and activation of p44/42 mitogen-activated protein kinase (ERK) and p38 mitogen-activated protein kinase (p38 MAPK). Our findings give the evidence that beta-escin sodium might have potential anti-angiogenic activity via its direct effects on ECs.