AMD3100抑制胃癌细胞的增殖和侵袭能力及其机制研究

目的:探讨CXCR4特异性非肽类受体拮抗剂AMD3100对胃癌细胞增殖和侵袭能力的影响及其可能的分子机制。方法:Western blot方法检测不同转移潜能胃癌细胞系中CXCR4蛋白的表达水平。以不同浓度的AMD3100处理MKN28-M和MKN28-NM细胞后,采用CCK-8检测胃癌细胞的增殖情况,Transwell实验观察胃癌细胞侵袭能力的变化。Western blot检测AMD3100处理后MKN28-M细胞中基质金属蛋白酶-9(MMP-9)、血管内皮生长因子(VEGF)的表达。结果:Western blot实验结果显示,高转移胃癌细胞MKN28-M中CXCR4的蛋白表达水平明显高于低转移胃癌细胞MKN28-NM,亲本细胞MKN28的CXCR4蛋白表达量很低。CCK-8和Transwell实验检测结果表明,AMD3100通过特异性阻断CXCR4的作用,显著抑制MKN28-M和MKN28-NM细胞的增殖能力(P<0.05)和侵袭能力(P<0.01),且其抑制均呈剂量依赖性。经AMD3100处理后,MKN28-M细胞中MMP-9和VEGF的蛋白表达水平降低。结论:AMD3100可能通过下调MMP-9、VEGF等分子的表达抑制胃癌细胞的增殖,减弱胃癌细胞的侵袭及转移能力。     

TAZ促进胃癌中血管生成及相关机制的研究

  目的   探究Hippo通路关键效应分子TAZ在胃癌组织中的表达及其在胃癌血管生成中的作用。  方法   通过免疫组织化学法分析150例胃癌组织标本中TAZ和β-catenin的表达情况；将TAZ过表达质粒及干扰质粒通过慢病毒分别转染至胃癌细胞系MGC803和MKN28中，通过细胞功能实验检测内皮细胞成管、增殖及迁移能力；使用Western blot法检测转染后的胃癌细胞中TAZ及β-catenin的表达情况；采用酶联免疫吸附试验（ELISA）检测TAZ转染后血管内皮生长因子（vascular endothelial growth factor，VEGF）蛋白表达的变化。  结果   免疫组织化学法结果显示150例胃癌组织中，TAZ阳性表达64例（阳性率43%），主要定位于细胞核，其表达与肿瘤分级、TNM分期、转移及微血管密度（microvessel density，MVD）有关（P < 0.05）。此外，在TAZ阳性组中β-catenin阳性表达率为67.2%，明显高于TAZ阴性组，TAZ的表达与β-catenin呈正相关。在MKN28细胞系中上调TAZ的表达，与HUVEC细胞共培养后增强了内皮细胞增殖及管道形成能力，此外还通过促进β-catenin的表达，增强了内皮细胞的迁移能力；相反，在MGC803细胞系中下调TAZ的表达，与HUVEC共培养后减弱了内皮细胞增殖和管道形成能力，此外还通过降低β-catenin的表达，抑制了内皮细胞的迁移能力。  结论  胃癌细胞TAZ的高表达可能通过促进β-catenin和VEGF的表达，进而增强胃癌血管生成能力。      

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。     

藏红花素对乳腺癌血管生成作用的实验研究

目的 探讨藏红花素（Crocin）对乳腺癌血管生成作用及可能机制。方法 MTT法检测Crocin对人乳腺癌细胞MDA-MB-231及人脐静脉内皮细胞（HUVEC）的增殖抑制作用,并筛选出合适的Crocin浓度;流式细胞术检测Crocin对MDA-MB-231细胞凋亡和周期的影响;Transwell及小管形成实验检测Crocin对HUVEC细胞迁移和小管形成的抑制作用;构建乳腺癌MDA-MB-231裸鼠移植瘤模型,给予7次Crocin（5 mg/ml）治疗,免疫组化检测Crocin治疗后裸鼠移植瘤组织中CD34及Ki-67的表达。结果 MTT法检测显示,Crocin对乳腺癌细胞MDA-MB-231有显著的增殖抑制作用（P＜0.05）,其48 h的半数抑制浓度（IC50）为5.0 mg／ml;而Crocin作用24 h时对HUVEC细胞有轻度增殖抑制作用,但不呈剂量依赖性,当Crocin作用48 h和72 h时,其增殖抑制作用明显增加,呈剂量依赖性,其48 h的IC50为5.97 mg／ml。流式细胞仪检测显示,Crocin可诱导MDA-MB-231细胞凋亡（P＜0.05）,还可诱导细胞阻滞于G2／M期,呈剂量依赖性（P＜0.05）。Transwell及小管形成实验显示,Crocin可抑制HUVEC细胞迁移（P＜0.05）和小管形成（P＜0.05）,均呈剂量依赖性。裸鼠皮下移植瘤实验显示,Crocin 5.0 mg／ml治疗后,治疗组较空白对照组移植瘤生长缓慢。空白对照组与治疗组CD34表达量分别为26.00±2.65和14.67±4.16（P＜0.05）,Ki-67表达量分别为502.67±88.48和262.67±75.08,差异均有统计学意义（P＜0.05）。结论 Crocin具有一定的抗血管生成作用,可能与其可以在体内抑制肿瘤细胞增殖、降低微血管密度,在体外可抑制血管内皮细胞增殖、迁移和小管形成的作用相关,具体的分子机制还有待进一步研究。     

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）通过押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教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。     

血根碱通过上调TSP-1抑制人脐静脉内皮细胞增殖

摘 要：［目的］ 探讨血根碱对人脐静脉内皮细胞（ human umbilical vein endothelial cells,HUVEC）的抑制作用及机理。［方法］ 培养HUVEC细胞,分为对照组、血根碱组,对照组加0.9%氯化钠液,血根碱组分别加1.00μmol/L、2.00μmol/L、3.00μmol/L、4.00μmol/L血根碱,48h后应用MTT法、细胞小管形成实验、Western blot法分别检测血根碱对HUVEC细胞增殖、小管形成、以及Bax、Caspase-3和血小板反应素-1 （thrombspondin-1,TSP-1）表达的影响。［结果］ 与对照组相比,血根碱组各浓度均可显著抑制HUVEC细胞增殖、小管形成,促进细胞凋亡及Caspase-3、Bax和TSP-1表达增高(P＜0.05)。［结论］ 血根碱通过上调TSP-1的表达,促进HUVEC细胞凋亡,抑制HUVEC细胞的增殖及新生血管形成,发挥抗血管生成的作用,阻碍肿瘤的发展。     

骨桥蛋白反义寡核苷酸抑制胃癌细胞MKN28粘附侵袭的实验研究

目的：骨桥蛋白（Osteopontin，OPN）是一种分泌型、粘附性的糖基化磷蛋白，许多肿瘤在发生发展过程中均伴有OPN的表达，而表达OPN的肿瘤也更易表现出侵袭、转移的倾向。本研究将观察OPN反义寡核苷酸（antisense oligonucleotide，ASODN）抑制高分化人胃癌细胞株MKN28粘附侵袭的作用。方法：用脂质体将骨桥蛋白ASODN转染胃癌细胞MKN28，实验分3组，对照组、随机序列寡核苷酸（random oligonucleotide，rODN）组和ASODN组。通过荧光定量RT—PCR、免疫组化方法、粘附细胞计数法、穿透小室聚碳酸酯膜侵袭实验分别测定骨桥蛋白mRNA和细胞表面骨桥蛋白的蛋白表达及癌细胞粘附力、侵袭力的变化。结果：转染后ASODN组骨桥蛋白mRNA的相对定量比值较对照组显著降低（1．83±0．10m3．32±0．16，P〈0．05）；免疫组化检测骨桥蛋白表达结果显示，转染后荧光强度明显降低，细胞表面骨桥蛋白表达下降（P〈0．01）；转染后ASODN组粘附力和侵袭力均较对照组显著下降（粘附细胞百分数为20．50±4．58vs41．50±8．40，穿透聚碳酸酯膜细胞数为21．80±6．90vs．42．00±9．40，P均小于0．01）。而rODN组上述各指标较对照组无明显变化。结论：骨桥蛋白的表达与粘附侵袭能力密切相关，反义寡核苷酸能有效抑制胃癌细胞株MKN28细胞骨桥蛋白基因的表达，从而抑制蛋白质的合成，降低其粘附侵袭能力。     

珠子参多糖通过靶向let-7a/CDK6分子轴调控胃癌MKN45细胞的增殖 与凋亡

目的：探讨珠子参多糖（panax japlcus var polysaccharide，PJPS）对胃癌MKN45细胞增殖和凋亡的影响及其调控机 制。方法：选用人胃癌细胞系HGC27、MGC803、MKN45和胃黏膜上皮细胞株GES-1，分别将let-7a mimics、let-7a inhibitor转染 进MKN45细胞； 以100 μg/ml PJPS处理胃癌细胞系并挑选后续实验细胞株为MKN45细胞；分别添加0、10、50、100、120 μg/ml PJPS处理转染后各组MKN45细胞， 用CCK-8法、流式细胞术分别检测MKN45细胞增殖活力和细胞凋亡率， 用Western blotting 检测MKN45细胞中细胞周期依赖性激酶6（cycle dependent kinase 6，CDK6）和凋亡相关蛋白的表达， 用qPCR法检测调控胃癌细 胞增殖的miRNAs表达水平。用双荧光素酶报告基因实验验证let-7a和CDK6的靶向关系。结果：与其他胃癌细胞比较，100 μg/ml PJPS可显著抑制 MKN45 细胞的增殖活力（P<0.01）；同时，100 μg/ml PJPS 处理后，可显著上调MKN45细胞中let-7a的表达 （P<0.01）。双荧光素酶报告基因实验证实CDK6是let-7a的靶基因。进一步实验显示，PJPS通过上调let-7a靶向抑制CDK6的表 达，从而抑制MKN45细胞的增殖并诱导其凋亡（均P<0.01）。结论：PJPS通过调控let-7a/CDK6分子轴抑制胃癌MKN45细胞的 增殖并诱导其凋亡。     

lncRNA-uc003uxs在缺氧诱导胃癌侵袭转移中的作用

目的:探讨长链非编码RNA（long non-coding RNA,lncRNA）-uc003uxs在缺氧诱导胃癌侵袭和转移中的作用。方法:三个胃癌细胞系SGC7901、MKN45、MKN28分别经常氧和缺氧孵育 24 h ,提取3例配对的胃癌细胞总RNA,利用高通量lncRNA芯片比较它们之间的表达谱差异,初步筛选与缺氧诱导胃癌侵袭转移相关的关键分子。RT-PCR法检测 lncRNA-uc003uxs在缺氧诱导的胃癌细胞（相对于常氧诱导的胃癌细胞）以及20对胃癌组织（相对于癌旁组织）中的表达水平。通过慢病毒转染,稳定下调SGC7901和MKN28细胞中lncRNA-uc003uxs的表达。通过Transwell迁移和侵袭实验以及裸鼠尾静脉注射内脏转移实验检测lncRNA-uc003uxs下调后对胃癌细胞侵袭和转移能力的影响。结果:高通量芯片分析结果显示:与常氧诱导的胃癌细胞相比,缺氧诱导的胃癌细胞 SGC7901、MKN45和MKN28中有84个共同上调的lncRNA分子以及70个共同下调的lncRNA分子,而多重筛选策略则提示:lncRNA-uc003uxs可能是缺氧诱导胃癌侵袭转移的关键lncRNA分子之一。RT-PCR结果表明:lncRNA-uc003uxs在缺氧诱导的胃癌细胞SGC7901、MKN45和MKN28中显著上调,其在胃癌组织中的表达水平也显著高于癌旁组织。Transwell实验结果显示:缺氧能够显著增加SGC7901和MKN28细胞的迁移和侵袭能力,而下调lncRNA-uc003uxs的表达后,两种细胞的迁移和侵袭能力明显下降。此外,裸鼠尾静脉内脏转移实验也证实lncRNA-uc003uxs的下调抑制了胃癌细胞SGC7901的体内肝肺转移能力。结论:利用高通量芯片筛选,在胃癌细胞中发现了一系列缺氧相关的lncRNA分子。临床标本分析及功能缺失试验证实:lncRNA-uc003uxs是一个缺氧诱导胃癌侵袭转移的关键lncRNA分子。     

Mitofusin-2 is a novel anti-angiogenic factor in pancreatic cancer

BackgroundAberrant expression of mitofusin-2 (MFN2) has been found to be associated with vascular endothelial growth factor A (VEGFA)-mediated angiogenesis in human umbilical vein endothelial cells (HUVECs). This study aimed to investigate the expression of MFN2 in pancreatic cancer (PC) and the role of MFN2 in vascular endothelial cell growth and angiogenesis.MethodsProtein and mRNA expression of MFN2 and VEGFA were measured. The CCK-8 assay, tube formation assay, flow cytometry, and transmission electron microscopy were used to examine the effects of MFN2 overexpression on HUVEC growth, angiogenesis, and apoptosis. Western blot and immunocytochemical staining were conducted to measure alterations in cell cycle and apoptosis regulators and vascular endothelial growth factor receptor 2 (VEGFR2), angiopoietin-1 gene (ANGPT1), and tissue inhibitor of metalloproteinase 1 (TIMP1) expression in HUVECs.ResultsThe results showed that MFN2 levels were significantly decreased in tumor tissues. Contrasting results were observed for VEGFA mRNA levels. MFN2 overexpression inhibited cell growth while promoting the formation of apoptotic bodies in HUVECs. Additionally, MFN2 overexpression enhanced the protein expression of p21 and p27 while attenuating the expression of proliferating cell nuclear antigen, VEGFA, VEGFR2, ANGPT1, and TIPM1 in HUVECs.ConclusionsIn conclusion, MFN2 expression negatively correlates with VEGFA expression in PC and inhibits endothelial cell growth and angiogenesis.     

Morphine promotes angiogenesis by activating PI3K/Akt/HIF-1α pathway and upregulating VEGF in hepatocellular carcinoma

BackgroundHepatocellular carcinoma (HCC) is characterized by the neo-angiogenesis induced by tumor and adjacent cells. It is a leading cancer-related cause of death. Morphine has effects on angiogenesis with pro-angiogenic or anti-angiogenic phonotypes. This study explores the function of morphine on cancer cell growth, angiogenesis and the underlying mechanism in HCC.MethodsMorphine was used to treat BEL-7402 or HCC-LM3 cells and human umbilical vein endothelial cells (HUVECs) were subsequently incubated in the conditioned media (CM) of HCC cells. The potential effects of cell proliferation, migration and tube formation of CM-treated HUVECs were investigated. Furthermore, the angiogenesis regulated factors of VEGFA, PIGF, ANG-1, ANG-2, FGF-1 and FGF-2 were assessed. siRNA and LY294002 were further used to explore the mechanism mediating the effects of morphine on the angiogenesis pathway. The neovascularization effect by morphine was confirmed through the use of human HCC cancer heterotopic mouse model in vivo.ResultsA significantly increased cell proliferation, migration, and tube formation effect of HUVECs induced by the CM from HCC cell lines treated with morphine was observed. More VEGFA secretion in CM from LM3 or BEL-7402 cell lines was found than the controls (P=0.03 and P=0.027, respectively). VEGFA knock-down could significantly reverse cell proliferation, migration and tube formation induced by the CM from HCC cell lines with morphine treatment. Further molecular experiments indicated that VEGFA secretion was activated by morphine potentially through the PI3K/Akt/HIF-1α pathway. Morphine-induced neovascularization was also observed by the IHC of CD31 and VEGFA.ConclusionsMorphine promotes angiogenesis in hepatocellular carcinoma possibly through the activation of the PI3K/Akt/HIF-1α pathway and VEGFA stimulation.     

Inhibition of gastric cancer cells associated angiogenesis by 15d-prostaglandin J2 through the downregulation of angiopoietin-1

Peroxisome proliferator-activated receptor gamma (PPARgamma) ligands have been shown to inhibit angiogenesis. We showed that treatment with 15d-PGJ(2), a PPARgamma ligand, downregulate the expressions of angiopoietin-1 (Ang-1) in gastric cancer cells MKN45. The medium of MKN45 cells treated with 15d-PGJ(2) significantly inhibited the migration and tube formation of human umbilical vein endothelial cells (HUVECs). Moreover, Matrigel plug assay revealed that 15d-PGJ(2) reduced in vivo angiogenesis induced by MKN45 cells. These modulations were restored by the addition of recombinant Ang-1. Our findings supported that 15d-PGJ(2) suppressed angiogenesis of gastric cancer cells by downregulation of Ang-1.     

PE, a new sulfated saponin from sea cucumber, exhibits anti-angiogenic and anti-tumor activities in vitro and in vivo

Here, we examined the in vitro and in vivo anti-angiogenesis and anti-tumor activities of PE, a new marine-derived compound. Inhibition of angiogenesis was assessed in vitro using proliferation, migration, adhesion, tube-formation and apoptosis assays in PE-treated HMECs and HUVECs. In vivo, CAM assays were used to assess inhibition effect of PE on physiological angiogenesis, and immunofluorescent microscopy was used to examine tumor microvessel density and apoptosis in PE-treated mouse tumor models. Finally, Western blotting analyses were performed to examine the effect of PE on VEGF signaling in HMECs. The results showed that PE inhibited proliferation of HMECs and HUVECs with IC50 values of 2.22 +/- 0.31 microM and 1.98 +/- 0.32 microM, induced endothelial cell apoptosis at concentrations <2 microM, induced dose-dependent suppression of cell migration, cell adhesion and tube formation in HMECs and HUVECs, and showed anti-proliferative activities against several tumor cell lines (IC50 values of approximately 4 microM). In vivo, PE (5 nM/egg) suppressed spontaneous angiogenesis in our CAM assay, and induced marked growth inhibition in mouse sarcoma 180 and hepatoma 22 models. Specifically, PE treatment reduced mouse sarcoma 180 tumor volume by triggering apoptosis of both tumor and tumor-associated endothelial cells, preferentially targeting on endothelial cells comparable with tumor cells. Finally, PE treatment suppressed the active (phosphorylated) forms of VEGFR2, Akt, ERK, FAK and paxillin, which are involved in endothelial cell survival, proliferation, adhesion and migration. Our results indicate that PE exerts an anti-angiogenic activity associated with inhibition of VEGFR2 signaling, and an anti-tumor activity associated with decreased proliferation of tumor cells and increased apoptosis of both endothelial cells and tumor cells.     

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.     

Integrin alphavbeta3 is not significantly implicated in the anti-migratory effect of anti-angiogenic urokinase kringle domain

The recombinant kringle domain (UK1) of urokinase-type plasminogen activator (uPA) has been shown to possess anti-angiogenic activity in vitro and in vivo. It has also been found to inhibit in vivo malignant glioma growth. In contrast, direct interaction of the kringle domain of uPA and integrin alphavbeta3 has been reported to be involved in plasminogen and leukocyte activation by uPA. Since integrin alphavbeta3 is involved in tumor angiogenesis, we investigated whether integrin alphavbeta3 is involved in the inhibitory function of UK1 in angiogenesis, by examining its anti-migratory activity. In a modified Boyden chamber assay, the Pichia-expressed UK1 dose-dependently inhibited the VEGF-induced migration of human umbilical vein endothelial cells (HUVECs). However, in the absence of growth factor stimulation, soluble UK1 alone did not induce or inhibit HUVEC migration. In cell adhesion, immobilized UK1 promoted HUVEC adhesion and spreading which were compared to BSA. Pretreatment of the anti-alphavbeta3 integrin antibody, significantly inhibited HUVEC binding to immobilized UK1, whereas neither anti-alpha2beta1 nor anti-alpha5beta1 integrin antibody had any effect, although pre-treatment of the soluble UK1 showed no marked alteration of the binding level of anti-alphavbeta3 antibody to HUVECs in FACS analysis. In a modified Boyden chamber assay, the function blocking antibodies against integrins alphavbeta3, alpha2beta1 and alpha5beta1 did not completely prevent the inhibitory effect of UK1 in HUVEC migration. These results suggest that UK1 interacts with integrin alphavbeta3, but its anti-migratory activity on endothelial cells is not significantly mediated by integrin alphavbeta3.     

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.     

Focal adhesion kinase inhibitors are potent anti-angiogenic agents

Focal adhesion kinase (FAK), a cytoplasmic tyrosine kinase and scaffold protein localized to focal adhesions, is uniquely positioned at the convergence point of integrin and receptor tyrosine kinase signal transduction pathways. FAK is overexpressed in many tumor cells, hence various inhibitors targeting its activity have been tested for anti-tumor activity. However, the direct effects of these pharmacologic agents on the endothelial cells of the vasculature have not been examined. Using primary human umbilical vein endothelial cells (HUVEC), we characterized the effects of two FAK inhibitors, PF-573,228 and FAK Inhibitor 14 on essential processes for angiogenesis, such as migration, proliferation, viability and endothelial cell tube formation. We observed that treatment with either FAK Inhibitor 14 or PF-573,228 resulted in reduced HUVEC viability, migration and tube formation in response to vascular endothelial growth factor (VEGF). Furthermore, we found that PF-573,228 had the added ability to induce apoptosis of endothelial cells within 36 h post-drug administration even in the continued presence of VEGF stimulation. FAK inhibitors also resulted in modification of the actin cytoskeleton within HUVEC, with observed increased stress fiber formation in the presence of drug. Given that endothelial cells were sensitive to FAK inhibitors at concentrations well below those reported to inhibit tumor cell migration, we confirmed their ability to inhibit endothelial-derived FAK autophosphorylation and FAK-mediated phosphorylation of recombinant paxillin at these doses. Taken together, our data indicate that small molecule inhibitors of FAK are potent anti-angiogenic agents and suggest their utility in combinatorial therapeutic approaches targeting tumor angiogenesis.     

WMJ-S-001, a novel aliphatic hydroxamate derivative,exhibits anti-angiogenic activities via Src-homology-2-domain-containing protein tyrosine phosphatase 1

Angiogenesis, one of the major routes for tumor invasion and metastasis represents a rational target for therapeutic intervention. Recent development in drug discovery has highlighted the diverse biological and pharmacological properties of hydroxamate derivatives. In this study, we characterized the anti-angiogenic activities of a novel aliphatic hydroxamate, WMJ-S-001, in an effort to develop novel angiogenesis inhibitors. WMJ-S-001 inhibited vascular endothelial growth factor (VEGF)-A-induced proliferation, invasion and endothelial tube formation of human umbilical endothelial cells (HUVECs). WMJ-S-001 suppressed VEGF-A-induced microvessel sprouting from aortic rings, and attenuated angiogenesis in in vivo mouse xenograft models. In addition, WMJ-S-001 inhibited the phosphorylations of VEGFR2, Src, FAK, Akt and ERK in VEGF-A-stimulated HUVECs. WMJ-S-001 caused an increase in SHP-1 phosphatase activity, whereas NSC-87877, a SHP-1 inhibitor, restored WMJ-S-001 suppression of VEGFR2 phosphorylation and cell proliferation. Furthermore, WMJ-S-001 inhibited cell cycle progression and induced cell apoptosis in HUVECs. These results are associated with p53 phosphorylation and acetylation and the modulation of p21 and survivin. Taken together, WMJ-S-001 was shown to modulate vascular endothelial cell remodeling through inhibiting VEGFR2 signaling and induction of apoptosis. These results also support the role of WMJ-S-001 as a potential drug candidate and warrant the clinical development in the treatment of cancer.