Zentrum der Chirurgie, Klinik für Urologie und Kinderurologie, Johann Wolfgang Goethe-Universität, 60596 Frankfurt am Main, Germany.
Neoplasia. 2009 Oct;11(10):1054-63. doi: 10.1593/neo.09762.
Tumor cells have evolved effective strategies to escape the host immune response. The objective of this study was to determine whether tumor cells can condition endothelial cells in a specific manner to prevent subsequent adhesion of polymorphonuclear neutrophils (PMNs) and/or peripheral blood lymphocytes (PBLs). Human umbilical vein endothelial cells (HUVECs) and UKF-NB-4 neuroblastoma tumor cells were established in coculture on opposite sides of porous transwell filters. After 24 hours with and without HUVEC conditioning, PMNs or PBLs were added to the HUVEC monolayer. Adhesion to conditioned HUVEC versus adhesion to nonconditioned HUVEC was compared. Effects on endothelial CD44v4, CD44v5, CD44v7, intercellular adhesion molecule 1 (ICAM-1), E-selectin, and vascular cell adhesion molecule 1 (VCAM-1) adhesion receptor expression were analyzed by flow cytometry, intracellular signaling proteins of the mitogen-activated protein kinase pathway and protein kinase C (PKC) subtypes quantified by Western blot analysis. Endothelial conditioning led to a distinct reduction in PMN but not in PBL adhesion to HUVEC. CD44 was significantly reduced, whereas ICAM-1, E-selectin, and VCAM-1 were not altered during HUVEC conditioning. Antibody blockade against CD44v4, CD44v5, and CD44v7 inhibited PMN but not PBL binding. The observed effects were caused by direct tumor cell-HUVEC contact because addition of isolated tumor cell membrane fragments but not of soluble cell culture supernatant to HUVEC induced the CD44 receptor loss. PKCalpha activity was strongly enhanced in conditioned HUVEC. Blocking PKC prevented the reduction in PMN binding, indicating that this protein is involved in PMN adhesion regulation. A novel tumor escape strategy is presented here. Cell contact-dependent adhesion of tumor cells to the vascular wall promotes down-regulation of endothelial CD44 receptor expression, impairing an effective neutrophil attack.
肿瘤细胞已经进化出有效的策略来逃避宿主的免疫反应。本研究的目的是确定肿瘤细胞是否可以以特定的方式调节内皮细胞，以防止随后多形核白细胞（PMN）和/或外周血淋巴细胞（PBL）的黏附。将人脐静脉内皮细胞（HUVEC）和 UKF-NB-4 神经母细胞瘤肿瘤细胞建立在多孔 Transwell 过滤器的相对侧的共培养物中。在有和没有 HUVEC 调节的情况下培养 24 小时后，将 PMN 或 PBL 添加到 HUVEC 单层中。将调节后的 HUVEC 的黏附与未调节的 HUVEC 的黏附进行比较。通过流式细胞术分析内皮细胞 CD44v4、CD44v5、CD44v7、细胞间黏附分子 1（ICAM-1）、E-选择素和血管细胞黏附分子 1（VCAM-1）黏附受体的表达，通过 Western blot 分析定量测定有丝分裂原激活的蛋白激酶途径和蛋白激酶 C（PKC）亚型的细胞内信号蛋白。内皮细胞调节导致 PMN 但不 PBL 对 HUVEC 的黏附明显减少。CD44 显著减少，而 ICAM-1、E-选择素和 VCAM-1 在 HUVEC 调节过程中没有改变。针对 CD44v4、CD44v5 和 CD44v7 的抗体阻断抑制了 PMN 但不抑制 PBL 结合。观察到的效应是由肿瘤细胞与内皮细胞的直接接触引起的，因为将分离的肿瘤细胞膜片段而不是可溶性细胞培养液上清液添加到 HUVEC 中诱导了 CD44 受体的丢失。在调节后的 HUVEC 中，PKCalpha 活性明显增强。阻断 PKC 可防止 PMN 结合减少，表明该蛋白参与 PMN 黏附调节。本文提出了一种新的肿瘤逃逸策略。肿瘤细胞与血管壁的细胞接触依赖性黏附促进内皮细胞 CD44 受体表达的下调，从而削弱了有效的中性粒细胞攻击。
