17β-雌二醇对大鼠心肌的促血管新生作用:促进微血管内皮细胞分泌VEGF

目的: 研究17β-雌二醇（17β-E2）对大鼠心肌微血管内皮细胞(CMEC)的促血管新生作用。方法: 以体外培养的CMECs为模型，用免疫荧光染色法检测雌激素受体(ER)的表达。用MTT比色法检测不同剂量的17β-E2对细胞增殖的影响。用细胞划痕法检测加入17β-E2后细胞的迁移能力。用Millicell小室测定法检测17β-E2对细胞侵入能力的影响。用管样结构形成实验观察加入17β-E2后细胞分化的情况。用ELISA法检测17β-E2对细胞分泌血管内皮生长因子（VEGF）的影响。结果: 免疫荧光染色法检测显示，心肌微血管内皮细胞内存在ER。MTT比色法检测表明，17β-E2可明显促进CMECs的增殖，在其浓度为0.01 μmol/L时，可产生最大的增殖效应；而雌激素的拮抗剂三苯氧胺（TMF）则可阻断此效应。同时发现，17β-E2处理组CMECs的迁移能力和管样结构形成的能力，均明显强于对照组及17β-E2+TMF处理组。与对照组及17β-E2+TMF处理组相比，17β-E2处理组可明显促进大鼠CMESs分泌VEGF（P<0.01）。结论: 在体外环境中，17β-E2可刺激CMECs自分泌VEGF，提高CMECs血管新生的活性。     

姜黄素抑制白细胞介素8诱导的血管内皮细胞迁移的分子机制

目的探讨姜黄素对白细胞介素(IL)-8诱导的血管内皮细胞迁移的影响及分子机制。方法应用IL-8、姜黄素及丝裂原活化蛋白激酶(MAPK)/细胞外信号调节激酶(ERK)信号通路抑制剂PD98059(PD)处理HUVECs细胞,Transwell和Western印迹实验检测细胞迁移、血管内皮生长因子(VEGF)、ERK1/2和磷酸化(p)-ERK1/2蛋白表达。结果 IL-8可显著促进HUVECs细胞迁移并上调VEGF和p-ERK1/2蛋白表达;姜黄素或PD可有效抑制IL-8诱导的HUVECs细胞迁移和VEGF表达。结论姜黄素和PD均能抑制IL-8诱导的HUVECs细胞迁移和VEGF表达,并且姜黄素能够显著抑制pERK1/2蛋白表达,提示抑制MAPK/ERK信号通路可能是姜黄素抗血管生成的部分机制。     

miR-132在动脉粥样硬化中的表达及对缺氧诱导的血管内皮细胞增殖凋亡的影响

目的探讨miR-132在动脉粥样硬化表达及对缺氧诱导的血管内皮细胞增殖凋亡的影响。方法 RT-PCR检测动脉粥样硬化中miR-132的表达;空转染组、阴性对照组和miR-132抑制剂组转染人脐静脉血管内皮细胞(HUVECs),转染48 h后RT-PCR检测各组细胞中miR-132 mRNA表达;后续实验分为正常培养组、缺氧组、缺氧+miR-132抑制剂组,各组细胞培养48 h后,CCK8及流式细胞仪分别检测细胞的增殖及凋亡情况;Western印迹检测活化的含半胱氨酸的天冬氨酸蛋白水解酶(Cleaved Caspase)3、磷酸化磷脂酰肌醇3-激酶(p-PI3K)、磷酸化蛋白激酶B(p-AKT)蛋白表达。结果 miR-132在动脉硬化组中的表达显著高于对照组(P0.05);转染组miR-132 mRNA表达显著低于空转染组(P0.05);缺氧组和缺氧+miR-132抑制剂组OD_(490)值及PI3K、p-AKT蛋白表达均显著低于正常培养组(P0.05),细胞凋亡率及Cleaved Caspase3蛋白表达显著高于正常培养组(P0.05),缺氧+miR-132抑制剂组OD_(490)值及PI3K、p-AKT蛋白表达显著高于缺氧组,细胞凋亡率及Cleaved Caspase3蛋白表达显著低于缺氧组(P0.05)。结论 miR-132在动脉粥样硬化中高表达,抑制其表达可促进血管内皮细胞增殖及降低细胞的凋亡,其机制与激活PI3K/AKT信号通路有关。     

缺氧活化AMPK/mTOR通路对脑血管内皮细胞增殖及代谢的影响

目的研究缺氧活化脑血管内皮细胞中AMPK及下游mTOR通路对脑血管内皮细胞增殖和代谢的调控作用。方法分别用正常氧对照组、低氧(15%、10%、5%、1%)处理脑血管内皮细胞。用CCK8方法检测脑血管内皮细胞增殖情况;流式细胞术检测脑血管内皮细胞活性氧(ROS)含量和细胞凋亡率;Western印迹检测细胞AMPK、mTOR的磷酸化水平及敲低AMPK和抑制mTOR后AMPK、mTOR的磷酸化水平。结果缺氧可抑制脑血管内皮细胞的增殖和代谢,并促进脑血管内皮细胞的凋亡;缺氧可上调脑血管内皮细胞中AMPK的磷酸化水平,下调mTOR的磷酸化水平;敲低AMPK后,mTOR的磷酸化水平升高,而抑制mTOR通路对AMPK的磷酸化水平无显著影响。结论缺氧可通过激活AMPK通路,进而抑制mTOR通路的活化,从而抑制脑血管内皮细胞的增殖和代谢,并促进脑血管内皮细胞凋亡。mTOR蛋白为AMPK通路下游的靶蛋白。     

缺氧条件下血管活性因子对血管内皮细胞中血管内皮生长因子表达的影响

目的　探讨在缺氧条件下人脐静脉血管内皮细胞血管内皮生长因子 (VEGF)表达及缩血管活性物质内皮素 ,舒血管活性物质NO和NO抑制剂LNNA对VEGF基因表达的影响。方法　体外培养人脐静脉血管内皮细胞 ,经缺氧及血管活性物质处理 ,Northern杂交、酶联免疫检测和计算机图像分析等观察VEGFmRNA和蛋白表达水平。结果　缺氧 6h内皮细胞可见VEGF表达。ET可促进VEGFmRNA的表达 ,NO可明显抑制VEGFmRNA的表达 ,NO抑制剂LNNA也影响VEGFmRNA的表达。ELISA检测VEGF蛋白水平分别为 6h组 (8 2± 1 1) μg/L ,ET +6h组 (9 37± 1 0 2 ) μg/L ,NO +6h组 (2 86± 0 91) μg/L ,LNNA +6h组 (14 75± 1 87)μg/L。 结论　缺氧可诱导人脐静脉血管内皮细胞分泌VEGF并受血管活性物质的调控 ,ET促进其表达 ,NO抑制其表达。     

加入结合胆红素与游离胆红素培养的人脐静脉内皮细胞增殖、迁移及血管生成能力比较

目的 比较结合胆红素（CB）和游离胆红素（UCB）对人脐静脉内皮细胞（HUVECs）增殖、迁移和血管生成能力的影响,并探讨其潜在的机制。方法 取传代培养的HUVECs,随机分为三组,CB组加入20μmol/L CB、UCB组加入20μmol/L UCB、Control组加入最大药物浓度的DMSO（体积比≤0.1%）。采用MTS法检测三组细胞增殖能力（OD值）,细胞划痕实验检测三组培养10、24 h的迁移能力（划痕修复率）,成管实验检测三组培养4、8、24 h的血管生成能力（管样结构数量）,Western blotting法检测三组细胞外信号调节激酶（ERK）、p-ERK1/2及蛋白激酶B(Akt)、pAkt308、p-Akt473蛋白表达。结果 UCB组、Control组、CB组OD值分别为0.48±0.05、0.81±0.02、1.56±0.07,三组OD值依次升高（P均<0.05）。与Control组比较,CB组培养10、24 h的划痕修复率及培养4、8、24 h的管样结构数量均升高,UCB组均降低（P均<0.05）。与Control组比较,CB组细胞ERK、Akt蛋白...     

生长激素促分泌物受体的内源性配体ghrelin促进大鼠心肌微血管内皮细胞体外血管生成

目的 探讨生长激素促分泌物受体的内源性配体 ghrelin 对大鼠心肌微血管内皮细胞增殖、迁移和体外血管生成的影响,并探讨其潜在的信号转导途径.方法 (1)植块法分离成年SD 雄性大鼠的心肌微血管内皮细胞,Ⅷ因子免疫组织化学鉴定细胞种类并传代培养.(2)通过逆转录聚合酶链反应(RT-PCR)、免疫荧光、酶联免疫吸附试验(ELISA)、免疫印迹法(Western blot)鉴定ghrelin及其天然受体(growth hormone secretagogue-receptor,GHS-R)在心肌微血管内皮细胞上mRNA 及蛋白的表达.(3)用不同浓度(10-9～10-7mol/L)的ghrelin干预心肌微血管内皮细胞后,检测心肌微血管内皮细胞的增殖、迁移及体外血管生成的变化.(4)用不同浓度(10-9～10-7 mol/L)的ghrelin 干预心肌微血管内皮细胞后,观察ERK2磷酸化表达.用MAPK/ERK2的特异性抑制剂PD98059提前干预细胞后,观察ghrelin对大鼠心肌微血管内皮细胞体外血管生成及ERK2磷酸化表达的变化.结果 (1)植块法培养的原代心肌微血管肉皮细胞纯度达95％左右,且具有形成管腔样结构的能力.(2)RT-PCR、免疫荧光、ELISA和Western blot检测发现ghrelin及GHS-R在心肌微血管内皮细胞上均有表达.(3)分别用10-9～10-7 mol/L的ghrelin干预心肌微血管内皮细胞后,发现10-8、10-7 mol/L ghrelin处理组心肌微血管内皮细胞的增殖明显高于正常对照组[分别为(12.37±0.70)和(12.73±0.78)pmol/L比(7.40±0.71)pmol/L,P值均为0.001],迁移亦明显高于正常对照组(分别为127.00±4.06和121.00±4.30比113.80±4.60,p值分别为0.001和0.03),体外的血管生成亦明显高于正常对照组[分别为(72.20±5.72)和(71.00±7.78)mm比(28.60±5.13)mm,P均＜0.001].(4)10-8、10-7mol/L ghrelin处理组ERK2的磷酸化表达水平明显高于正常对照组(分别为0.92±0.13和1.15 ±0.16比0.29±0.04,P均＜0.001).若提前用PD98059干预细胞,则能明显抑制ghrelin诱导的体外血管生成及ERK2的磷酸化表达.结论 ghrelin及其受体GHS-R在大鼠心肌微血管内皮细胞上均有表达,ghrelin可通过激活ERK2的磷酸化促进心肌微血管内皮细胞的体外血管生成.     

Apelin经Akt/AMPK信号通路促进心肌微血管内皮细胞血管生成

目的:探讨apelin-13对大鼠心肌微血管内皮细胞(MVECs)的生物学效应及其可能的信号通路。方法:体外培养大鼠的心肌微血管内皮细胞。给予不同浓度apelin-13,采用MTT法观察细胞增殖能力、划痕损伤修复和Transwell方法观察细胞迁移能力、体外管腔样结构形成方法观察细胞管腔成能力。进一步采用蛋白印迹法观察apelin-13对Akt和AMPK分子蛋白的磷酸化水平的影响。结果:Apelin-13能增加大鼠微血管内皮细胞的增殖、迁移和体外管腔形成能力,且呈剂量依赖性在200 nmol/L浓度时促血管生成能力最佳。Apelin-13能上调细胞的Akt和AMPK磷酸化程度。结论:Apelin-13可促进MVECs的血管生成,可能与上调Akt和AMPK的磷酸化相关。     

与膜-细胞骨架连接蛋白家族结合的磷酸化蛋白50对血管内皮细胞增殖、迁移及成管能力的影响

目的探讨与膜-细胞骨架连接蛋白家族结合的磷酸化蛋白50(EBP50)对人脐静脉内皮细胞(HUVEC)内Akt1磷酸化水平、细胞分泌明胶酶的活性以及细胞骨架表达和分布的影响,阐明其影响人血管内皮细胞增殖、迁移及成管的分子机制。方法构建EBP50的真核重组表达载体,将重组质粒分别稳定转染HUVEC细胞系,经Western blot法验证后,采用MTT法检测细胞的增殖活性;应用划痕法检测细胞的迁移能力;应用Matrigel法检测细胞的成管能力;应用Western blot检测EBP50对Akt1磷酸化水平的影响;应用明胶酶谱法检测HUVEC细胞分泌的明胶酶活性;应用免疫荧光观察细胞骨架的分布。结果转染的外源性EBP50 cDNA片段已整合到基因组中;与对照组细胞比较,EBP50能显著抑制细胞的增殖、迁移及成管能力,并且EBP50明显下调Akt1的磷酸化水平(t=2.98,P<0.01);同时使HUVEC分泌的MMP2活性下降,并影响血管内皮细胞内细胞骨架的分布。结论EBP50可以抑制HUVEC细胞的增殖、迁移及成管,其机制可能与调整Akt1的磷酸化水平、调节细胞分泌明胶酶的活性及影响微丝细胞骨架分布有关。     

脂联素对内皮祖细胞增殖和迁移能力的影响

目的研究脂联素通过磷酸肌醇3激酶/蛋白激酶B(Akt)通路改善内皮祖细胞(EPC)增殖、迁移能力的影响并探讨其可能机制。方法利用密度梯度离心法分离、培养人外周血单个核细胞,将EPC分为对照组、脂联素组(10μg/ml)、磷酸肌醇3激酶抑制剂干预组(干预1组)和细胞外信号调节蛋白激酶(ERK)抑制剂干预组(干预2组)。采用四唑盐比色法、细胞集落形成单位计数等方法观察各组EPC增殖能力的变化情况,应用transwell小室法分析EPC迁移能力,采用免疫蛋白印迹法观察脂联素处理EPC后,Akt、磷酸化Akt、ERK、磷酸化ERK的表达情况。结果脂联素组EPC增殖能力较对照组明显提高(P<0.05),干预1组EPC增殖、迁移效应较脂联素组明显抑制(P<0.05),而干预2组对EPC增殖、迁移改善效应无明显影响。与对照组比较,脂联素组磷酸化Akt表达明显增加,干预1组磷酸化Akt表达及脂联素组磷酸化ERK表达无明显增加。结论脂联素具有促进EPC增殖、迁移等功能活性的作用,其主要机制可能与磷酸肌醇3激酶/Akt信号通路激活有关。     

Methylnaltrexone inhibits opiate and VEGF-induced angiogenesis: role of receptor transactivation

Angiogenesis or the formation of new blood vessels is important in the growth and metastatic potential of various cancers. Therefore, agents that inhibit angiogenesis have important therapeutic implications in numerous malignancies. We examined the effects of methylnaltrexone (MNTX), a peripheral mu opioid receptor antagonist, on agonist-induced human EC proliferation and migration, two key components in angiogenesis. Using human dermal microvascular EC, we observed that morphine sulfate (MS), the active metabolite, morphine-6-glucuronide (M6G), DAMGO ([d-Ala(2), N-Me-Phe(4), Gly(5)-ol]enkaphalin) and VEGF induced migration which were inhibited by pretreatment with MNTX at therapeutically relevant concentration (0.1 microM). The biologically inactive metabolite morphine-3-glucuronide (M3G) did not affect EC migration. We next examined the mechanism(s) by which MNTX inhibits opioid and VEGF-induced angiogenesis using human pulmonary microvascular EC. MS and DAMGO induced Src activation which was required for VEGF receptor transactivation and opioid-induced EC proliferation and migration. MNTX inhibited MS, DAMGO and VEGF induced tyrosine phosphorylation (transactivation) of VEGF receptors 1 and 2. Furthermore, MS, DAMGO and VEGF induced RhoA activation which was inhibited by MNTX or VEGF receptor tyrosine kinase inhibition. Finally, MNTX or silencing RhoA expression (siRNA) blocked MS, DAMGO and VEGF-induced EC proliferation and migration. Taken together, these results indicate that MNTX inhibits opioid-induced EC proliferation and migration via inhibition of VEGF receptor phosphorylation/transactivation with subsequent inhibition of RhoA activation. These results suggest that MNTX inhibition of angiogenesis can be a useful therapeutic intervention for cancer treatment.     

LDL attenuates VEGF-induced angiogenesis via mechanisms involving VEGFR2 internalization and degradation following endosome-trans-Golgi network trafficking

Considerable efforts have been made to amplify angiogenesis under conditions of hypoxia and ischemia by vascular endothelial growth factor (VEGF) delivery, so far with limited success. Ischemic vascular diseases are often associated with hypercholesterolemia. To elucidate whether the exposure to blood lipids influences VEGF responses of microvessels, we characterized effects of low density lipoprotein (LDL) exposure on the proliferation, migration and tube formation of human umbilical vein endothelial cells. By examining the expression, phosphorylation and downstream signals of VEGF’s receptor VEGFR2, we characterized mechanisms controlling angiogenic responses following LDL exposure. LDL attenuated endothelial proliferation, migration and tube formation in a dose-dependent way. Reduced abundance of VEGFR2 and VEGFR1 were noticed in LDL-exposed endothelial cells. In subcellular localization studies that we combined with pharmacological experiments, we showed that the loss of VEGFR2 resulted from its internalization and degradation, the latter of which required syntaxin-16-dependent endosome-trans-Golgi network trafficking. As a consequence, VEGFR2 phosphorylation and downstream signals -specifically Akt and ERK1/2 phosphorylation- were attenuated in response to VEGF treatment. VEGF only partly reversed the effects of LDL on angiogenesis under conditions of normoxia and hypoxia. Our results suggest that angiogenic responses to VEGF are compromised in hypercholesterolemia as a consequence of endosomal VEGFR2 degradation.     

Inhibition of angiogenesis by vitamin D-binding protein: Characterization of anti-endothelial activity of DBP-maf

Angiogenesis is a complex process involving coordinated steps of endothelial cell activation, proliferation, migration, tube formation and capillary sprouting with participation of intracellular signaling pathways. Regulation of angiogenesis carries tremendous potential for cancer therapy. Our earlier studies showed that vitamin D-binding protein-macrophage activating factor (DBP-maf) acts as a potent anti-angiogenic factor and inhibits tumor growth in vivo. The goal of this investigation was to understand the effect of DBP-maf on human endothelial cell (HEC) and the mechanism of angiogenesis inhibition. DBP-maf inhibited human endothelial cell (HEC) proliferation by inhibiting DNA synthesis ( μg/ml). DBP-maf significantly induced S- and G0/G1-phase arrest in HEC in 72 h. DBP-maf potently blocked VEGF-induced migration, tube-formation of HEC in a dose dependent manner. In addition, DBP-maf inhibited growth factor-induced microvessel sprouting in rat aortic ring assay. Moreover, DBP-maf inhibited VEGF signaling by decreasing VEGF-mediated phosphorylation of VEGFR-2 and ERK1/2, a downstream target of VEGF signaling cascade. However, Akt activation was not affected. These studies collectively demonstrate that DBP-maf inhibits angiogenesis by blocking critical steps such as HEC proliferation, migration, tube formation and microvessel sprouting. DBP-maf exerts its effect by inhibiting VEGR-2 and ERK1/2 signaling cascades. Understanding the cellular and molecular mechanisms of anti-endothelial activity of DBP-maf will allow us to develop it as an angiogenesis targeting novel drug for tumor therapy.     

Inhibition of angiogenesis by vitamin D-binding protein: characterization of anti-endothelial activity of DBP-maf

Angiogenesis is a complex process involving coordinated steps of endothelial cell activation, proliferation, migration, tube formation and capillary sprouting with participation of intracellular signaling pathways. Regulation of angiogenesis carries tremendous potential for cancer therapy. Our earlier studies showed that vitamin D-binding protein-macrophage activating factor (DBP-maf) acts as a potent anti-angiogenic factor and inhibits tumor growth in vivo. The goal of this investigation was to understand the effect of DBP-maf on human endothelial cell (HEC) and the mechanism of angiogenesis inhibition. DBP-maf inhibited human endothelial cell (HEC) proliferation by inhibiting DNA synthesis (IC(50) = 7.8 +/- 0.15 microg/ml). DBP-maf significantly induced S- and G0/G1-phase arrest in HEC in 72 h. DBP-maf potently blocked VEGF-induced migration, tube-formation of HEC in a dose dependent manner. In addition, DBP-maf inhibited growth factor-induced microvessel sprouting in rat aortic ring assay. Moreover, DBP-maf inhibited VEGF signaling by decreasing VEGF-mediated phosphorylation of VEGFR-2 and ERK1/2, a downstream target of VEGF signaling cascade. However, Akt activation was not affected. These studies collectively demonstrate that DBP-maf inhibits angiogenesis by blocking critical steps such as HEC proliferation, migration, tube formation and microvessel sprouting. DBP-maf exerts its effect by inhibiting VEGR-2 and ERK1/2 signaling cascades. Understanding the cellular and molecular mechanisms of anti-endothelial activity of DBP-maf will allow us to develop it as an angiogenesis targeting novel drug for tumor therapy.     

Angiotensin II type 2 receptor inhibits vascular endothelial growth factor-induced migration and in vitro tube formation of human endothelial cells

Endothelial cell migration and tube formation in response to vascular endothelial growth factor (VEGF) play an important role in the process of angiogenesis. Recent data indicate that angiotensin type 2 (AT2) receptor stimulation is antiangiogenic. Therefore, we studied the effect of angiotensin II (Ang II) on VEGF-induced migration and in vitro tube formation of human endothelial cells. Ang II inhibited VEGF-induced migration of EA.hy926 cells, human coronary artery (HCA) and human dermal microvascular (HDM) endothelial cells (ECs) as well as tube formation by HDMECs. The AT2 receptor antagonist PD123,319 but not the AT1 receptor antagonist losartan blocked the inhibitory effect of Ang II. The inhibitory effect of Ang II on VEGF-induced migration of endothelial cells was mimicked by the specific AT2 receptor agonist CGP-42112A. The phosphorylation of Akt and its downstream effector endothelial NO synthase (eNOS) is pivotal to VEGF-induced angiogenesis. We therefore investigated the effect of Ang II on VEGF-induced Akt and eNOS phosphorylation. Ang II diminished the VEGF-induced phosphorylation of Akt and eNOS in endothelial cells, whereas the autophosphorylation of VEGF receptors was unaffected. CGP-42112A again mimicked and PD123,319 but not losartan blocked the inhibitory effect of Ang II. Treatment of endothelial cells with pertussis toxin (PTX) totally abolished the AT2 receptor-mediated inhibition of VEGF-induced endothelial cell migration and blocked the inhibition of Akt and eNOS phosphorylation. In conclusion, this study indicates that AT2 receptor stimulation inhibits VEGF-induced endothelial cell migration and tube formation via activation of a PTX-sensitive G protein. These findings may explain the reported antiangiogenic properties of the AT2 receptor.     

JTT-705 blocks cell proliferation and angiogenesis through p38 kinase/p27(kip1) and Ras/p21(waf1) pathways

The excessive proliferation and migration of vascular smooth muscle cells (SMCs) participate in the growth and instability of atherosclerotic plaque. We examined the direct role of a newly developed chemical inhibitor of cholesteryl ester transfer protein, JTT-705, on SMC proliferation and angiogenesis in endothelial cells (ECs). JTT-705 inhibited human coronary artery SMC proliferation. JTT-705 induced the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and extracellular-signal-regulated kinases (ERK) in SMCs. In addition, the anti-proliferative effects of JTT-705 in SMCs were blocked by p38 MAPK inhibitor. JTT-705 induced the upregulation of p-p21(waf1), and this effect was blocked by dominant-negative Ras (N17), but not by inhibitors of p38 MAPK or ERK. In addition, JTT-705 also induced the upregulation of p27(kip1), and this effect was blocked by p38 MAPK inhibitor. Interestingly, culture medium from JTT-705-treated SMCs blocked human coronary artery EC tube formation in an in vitro model of angiogenesis indirectly via a decrease in vascular endothelial growth factor (VEGF) from SMCs and directly via an anti-proliferative effect in ECs. JTT-705 blocked the proliferation of SMCs through the activation of p38 kinase/p27(kip1) and Ras/p21(waf1) pathways, and simultaneously blocked EC tube formation associated with a decrease in VEGF production from SMCs and an anti-proliferative effect in ECs. Our results indicate that JTT-705 may induce a direct anti-atherogenic effect in addition to its inhibitory effect of CETP activity.     

Berberine inhibits angiogenic potential of Hep G2 cell line through VEGF down-regulation in vitro

Background and Aim: Berberine, an herbal alkaloid, has been reported to have promotion potential of apoptosis and anticancer effect on a variety of human tumor cells. To obtain more specific understanding of those consequences of berberine on hepatocellular carcinoma (HCC) and the tumor microenvironment, we conducted in vitro experiments to investigate the inhibitory effect of berberine on tumor‐induced angiogenesis using HCC cells and human umbilical vein endothelial cells (HUVECs). Methods: Human umbilical vein endothelial cell growth was quantified with the CCK‐8 cell proliferation assay; cell migration was observed with a Boyden chamber (Transwell, Corning, Lowell, MA, USA), and angiogenesis was assessed by endothelial tube formation in Matrigel in vitro. In addition, VEGF level was determined by ELISA and VEGF mRNA expression by RT‐PCR. Results: Berberine inhibited the capacity of HCC to stimulate HUVEC's proliferation, migration and endothelial tube formation, suggesting that berberine could influence the cross‐talk between the HCC cell and vascular endothelial cells. These results demonstrate berberine's antiangiogenesis property and its clinical potential as an inhibitor of tumor angiogenesis. Subsequently analyses reveal that berberine prevents secretion of VEGF from HCC and down‐regulates VEGF mRNA expression. Conclusion: These findings strongly suggest that berberine is a potential antiangiogenic agent and a promising antitumor drug for HCC.