Kim Myoung H
Department of Molecular Biology and Immunology and Institute for Cancer Research, University of North Texas Health Science Center, Fort Worth, Texas 76107-2699, USA.
J Cell Biochem. 2003 Jun 1;89(3):529-38. doi: 10.1002/jcb.10543.
Flavonoids have been proposed to act as chemopreventive agents in numerous epidemiological studies and have been shown to inhibit angiogenesis and proliferation of tumor cells and endothelial cells in vitro. Angiogenesis requires tightly controlled extracellular matrix degradation mediated by extracellular proteolytic enzymes including matrix metalloproteinases (MMPs) and serine proteases, in particular, the urokinase-type plasminogen activator (uPA)-plasmin system. In this study, we have investigated the antiangiogenic mechanism of the flavonoids, genistein, apigenin, and 3-hydroxyflavone in a human umbilical vein endothelial cell (HUVEC) model. The stimulation of serum-starved HUVECs with vascular endothelial growth factor/basic fibroblast growth factor (VEGF/bFGF) caused marked increase in MMP-1 production and induced the pro-MMP-2 activation accompanied by the increase in MT1-MMP expression. However, pretreatment with flavonoids before VEGF/bFGF stimulation completely abolished the VEGF/bFGF-stimulated increase in MMP-1 and MT1-MMP expression and pro-MMP-2 activation. Genistein blocked VEGF/bFGF-stimulated increase in TIMP-1 expression and decrease in TIMP-2 expression. Apigenin and 3-hydroxyflavone further decreased TIMP-1 expression below basal level and completely abolished TIMP-2 expression. VEGF and bFGF stimulation also significantly induced uPA expression, most strikingly the level of 33 kDa uPA, and increased the expression of PA inhibitor (PAI)-1. Genistein, apigenin, and 3-hydroxyflavone effectively blocked the generation of 33 kDa uPA, and further decreased the activity of the 55 kDa uPA and the expression of PAI-1 below the basal level. In conclusion, these data suggest that genistein, apigenin, and 3-hydroxyflavone inhibit in vitro angiogenesis, in part via preventing VEGF/bFGF-induced MMP-1 and uPA expression and the activation of pro-MMP-2, and via modulating their inhibitors, TIMP-1 and -2, and PAI-1.
在众多流行病学研究中，黄酮类化合物被认为具有化学预防作用，并且在体外实验中已显示出能抑制肿瘤细胞和内皮细胞的血管生成及增殖。血管生成需要由细胞外蛋白水解酶介导的严格控制的细胞外基质降解，这些酶包括基质金属蛋白酶（MMPs）和丝氨酸蛋白酶，特别是尿激酶型纤溶酶原激活剂（uPA）-纤溶酶系统。在本研究中，我们在人脐静脉内皮细胞（HUVEC）模型中研究了黄酮类化合物染料木黄酮、芹菜素和3-羟基黄酮的抗血管生成机制。用血管内皮生长因子/碱性成纤维细胞生长因子（VEGF/bFGF）刺激血清饥饿的HUVEC，导致MMP-1产生显著增加，并诱导前MMP-2激活，同时MT1-MMP表达增加。然而，在VEGF/bFGF刺激前用黄酮类化合物预处理，完全消除了VEGF/bFGF刺激引起的MMP-1和MT1-MMP表达增加以及前MMP-2激活。染料木黄酮阻断了VEGF/bFGF刺激引起的TIMP-1表达增加和TIMP-2表达减少。芹菜素和3-羟基黄酮进一步将TIMP-1表达降低至基础水平以下，并完全消除了TIMP-2表达。VEGF和bFGF刺激也显著诱导uPA表达，最显著的是33 kDa uPA的水平，并增加了纤溶酶原激活物抑制剂（PAI）-1的表达。染料木黄酮、芹菜素和3-羟基黄酮有效阻断了33 kDa uPA的产生，并进一步将55 kDa uPA的活性和PAI-1的表达降低至基础水平以下。总之，这些数据表明，染料木黄酮、芹菜素和3-羟基黄酮部分通过阻止VEGF/bFGF诱导的MMP-1和uPA表达以及前MMP-2的激活，并通过调节其抑制剂TIMP-1和-2以及PAI-1来抑制体外血管生成。
