Department of Molecular Oncology, Kyoto University Graduate School of Medicine, Japan.
Mol Cancer Res. 2010 May;8(5):665-76. doi: 10.1158/1541-7786.MCR-09-0351. Epub 2010 Apr 20.
Vascular endothelial cells produce considerable amounts of matrix metalloproteinases (MMP), including MMP-2, MMP-9, and membrane type 1 (MT1)-MMP. However, little is known about the regulatory mechanisms of these protease activities exhibited during vascular development. A glycosylphosphatidylinositol-anchored glycoprotein, reversion-inducing cysteine-rich protein with Kazal motifs (RECK), has been shown to attenuate MMP-2 maturation by directly interacting with MT1-MMP. Here, we show that an angiogenic factor angiopoietin-1 induces RECK expression in human umbilical vein endothelial cells (HUVEC), and RECK depletion in these cells results in defective vascular tube formation and cellular senescence. We further observed that RECK depletion downregulates beta1-integrin activation, which was associated with decreased autophosphorylation of focal adhesion kinase and increased expression of a cyclin-dependent kinase inhibitor p21(CIP1). In agreement, significant downregulation of beta1-integrin activity was observed in vascular endothelial cells in Reck-/- mouse embryos. In HUVECs, specific inhibition of MMP-2 significantly antagonized the effect of RECK depletion on beta1-integrin signaling, cell proliferation, and tube elongation. Furthermore, we observed that hypervascular tumor-derived cell lines can induce high RECK expression in convoluted vascular endothelial cells, and this in turn supports tumor growth. Targeting RECK specifically in tumor-associated vascular endothelial cells resulted in tumor regression. Therefore, we propose that RECK in tumor vascular endothelial cells can be an interesting target of cancer treatment via abortion of tumor angiogenesis.
血管内皮细胞产生大量基质金属蛋白酶（MMP），包括 MMP-2、MMP-9 和膜型 1（MT1）-MMP。然而，对于这些蛋白酶活性在血管发育过程中表现出的调节机制知之甚少。一种糖基磷脂酰肌醇锚定糖蛋白，富含半胱氨酸的 Kazal 基序的反转诱导蛋白（RECK），已被证明通过直接与 MT1-MMP 相互作用来减弱 MMP-2 的成熟。在这里，我们表明血管生成因子血管生成素-1 诱导人脐静脉内皮细胞（HUVEC）中 RECK 的表达，并且这些细胞中 RECK 的耗竭导致血管管腔形成和细胞衰老缺陷。我们进一步观察到 RECK 的耗竭下调了β1-整联蛋白的激活，这与粘着斑激酶的自磷酸化减少和细胞周期蛋白依赖性激酶抑制剂 p21(CIP1)的表达增加有关。一致地，在 Reck-/- 小鼠胚胎中的血管内皮细胞中观察到β1-整联蛋白活性的显著下调。在 HUVEC 中，MMP-2 的特异性抑制显著拮抗了 RECK 耗竭对β1-整联蛋白信号、细胞增殖和管腔伸长的影响。此外，我们观察到高血管肿瘤衍生细胞系可以诱导迂曲血管内皮细胞中高 RECK 表达，这反过来又支持肿瘤生长。特异性靶向肿瘤相关血管内皮细胞中的 RECK 导致肿瘤消退。因此，我们提出肿瘤血管内皮细胞中的 RECK 可能是通过终止肿瘤血管生成来治疗癌症的一个有趣靶点。
