Microtubule-targeting agents inhibit angiogenesis at subtoxic concentrations, a process associated with inhibition of Rac1 and Cdc42 activity and changes in the endothelial cytoskeleton
Microtubule-targeting agents inhibit angiogenesis at subtoxic concentrations, a process associated with inhibition of Rac1 and Cdc42 activity and changes in the endothelial cytoskeleton
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DOI：
10.1158/1535-7163.mct-06-0242
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发表时间：
2006-09-01
影响因子：
5.7
通讯作者：
Boven, Epie
中科院分区：
文献类型：
--
作者：
Bijman, Marcel N. A.;van Nieuw Amerongen, Geerten P.;Boven, Epie
微管结构紊乱，F-actin应力纤维形成减少，核F-actin环出现。这些观察结果与Rac 1和Cdc 42活性的早期抑制有关。总之，微管靶向剂的HNTCs通过干扰微管动力学阻止Rac 1/Cdc 42的活化和破坏肌动蛋白细胞骨架来有效地降低内皮细胞运动性。传统的抗癌药物可能显示出抗血管生成的作用，但其潜在的机制知之甚少。我们测定了顺铂、阿霉素、微管靶向药物多西他赛、埃博霉素B和长春碱在不影响细胞增殖的浓度下的抗血管生成特性。我们还评估了微管蛋白和肌动蛋白的形态和细胞运动中的两个关键分子，小Rho GTPases Cdc 42和Rac 1的活性。每种药物的最高无毒浓度（HNTC）定义为药物暴露1小时后最大抑制10%人脐静脉内皮细胞生长的浓度，顺铂10 μ mol/L、多柔比星100 nmol/L、多西他赛10 nmol/L、埃博霉素B 1 nmol/L和长春碱10 nmol/L。使用HNTCs暴露1小时的比较性内皮细胞功能测定表明，多西他赛、埃博霉素B和长春碱显著抑制了伤口测定中的内皮细胞迁移、transwell侵袭系统中的内皮细胞侵袭以及Matrigel层上的内皮细胞形成管状结构（P < 0.05），但顺铂和多柔比星不抑制。多西他赛对内皮细胞运动的抑制作用略高于埃博霉素B和长春碱。荧光显微镜显示，只有微管靶向剂影响微管蛋白和F-actin细胞骨架的完整性，这表明微管结构紊乱，F-actin应力纤维形成减少，以及核F-actin环的出现。这些观察结果与Rac 1和Cdc 42活性的早期抑制有关。总之，微管靶向剂的HNTCs通过干扰微管动力学阻止Rac 1/Cdc 42的活化和破坏肌动蛋白细胞骨架来有效地降低内皮细胞运动性。
disturbed microtubule structures, less F-actin stress fiber formation, and appearance of nuclear F-actin rings. These observations were associated with early inhibition of Rac1 and Cdc42 activity. In conclusion, HNTCs of microtubule-targeting agents efficiently reduce endothelial cell motility by interference with microtubule dynamics preventing the activation of Rac1/Cdc42 and disorganizing the actin cytoskeleton. Conventional anticancer agents may display antiangiogenic effects, but the underlying mechanism is poorly understood. We determined the antiangiogenic properties of cisplatin, doxorubicin, and the microtubule-targeting agents docetaxel, epothilone B, and vinblastine at concentrations not affecting cell proliferation. We also assessed tubulin and actin morphology and the activity of two key molecules in cell motility, the small Rho GTPases Cdc42 and Rac1. The highest non-toxic concentration (HNTC) of each drug was defined as the concentration inhibiting a maximum of 10% human umbilical vein endothelial cell growth on a 1-hour drug exposure, being for cisplatin 10 mu mol/L, doxorubicin 100 nmol/L, docetaxel 10 nmol/L, epothilone B 1 nmol/L, and vinblastine 10 nmol/L. Comparative endothelial cell functional assays using HNTCs for an exposure time of 1 hour indicated that endothelial cell migration in the wound assay, endothelial cell invasion in a transwell invasion system, and endothelial cell formation into tubelike structures on a layer of Matrigel were significantly inhibited by docetaxel, epothilone B, and vinblastine (P < 0.05), but not by cisplatin and doxorubicin. Docetaxel was slightly more efficient in the inhibition of endothelial cell motility than epothilone B and vinblastine. Fluorescence microscopy revealed that only the microtubule-targeting agents affected the integrity of the tubulin and F-actin cytoskeleton, which showed disturbed microtubule structures, less F-actin stress fiber formation, and appearance of nuclear F-actin rings. These observations were associated with early inhibition of Rac1 and Cdc42 activity. In conclusion, HNTCs of microtubule-targeting agents efficiently reduce endothelial cell motility by interference with microtubule dynamics preventing the activation of Rac1/Cdc42 and disorganizing the actin cytoskeleton.