Clezardin P, Drouin J, Morel-Kopp M C, Hanss M, Kehrel B, Serre C M, Kaplan C, Delmas P D
INSERM Research Unit 234, Hôpital Edouard Herriot, Lyon, France.
Cancer Res. 1993 Oct 1;53(19):4695-700.
We have previously shown that the platelet-aggregating activity of human MG-63 and HOS osteosarcoma cells depends at least in part upon tumor cell surface-associated thrombospondin, and suggested that platelet-osteosarcoma cell interactions could occur through interactions with specific platelet membrane receptors. In this study, the platelet-aggregating activity of MG-63 and HOS cells was studied by using a variety of platelet disorders. Both osteosarcoma cell lines induced a biphasic platelet aggregation response when added to normal platelet-rich plasma, while the second phase of aggregation was absent when added to gray platelets (deficiency in alpha-granule proteins) and to aspirin-treated platelets. Platelets from two unrelated patients with type I Glanzmann's thrombasthenia (deficiency in glycoprotein (GP) GPIIb/IIIa) did not aggregate at all with osteosarcoma cells. Using giant platelets from three patients with Bernard-Soulier syndrome (deficiency in GPIb/IX), the aggregation response induced by MG-63 and HOS cells was monophasic and reversible when compared to normal-sized platelets and to giant platelets from a patient with May-Hegglin anomaly (no membrane GP defect). Because GPIb serves as a receptor for von Willebrand factor during hemostasis, aggregation experiments were also conducted with the platelet-rich plasma of two patients with a low plasma von Willebrand factor concentration (type I von Willebrand's disease) before and after the infusion of deamino-D-arginine vasopressin. MG-63 and HOS cells induced biphasic platelet aggregation both before and after deamino-D-arginine vasopressin treatment, while the ristocetin-dependent binding of von Willebrand factor to platelets only occurred after deamino-D-arginine vasopressin treatment. Preincubation of normal platelet-rich plasma with monoclonal antibody SZ-2 directed against the von Willebrand binding domain of GPIb did not inhibit the platelet-aggregation activity of osteosarcoma cells, whereas anti-GPIb antibody SZ-2 did inhibit ristocetin-induced platelet agglutination. In addition, anti-GPIX antibodies did not affect platelet-osteosarcoma cell interactions. In conclusion, our data demonstrate that the first phase of the platelet-aggregating activity of human osteosarcoma cells is initiated by the interaction of these tumor cells with platelet membrane GPIIb/IIIa, whereas the second phase, even if plasma von Willebrand factor is deficient, involves platelet membrane GPIb and the participation of platelet alpha-granule proteins in membrane-mediated events, making aggregation irreversible.
我们之前已经表明，人MG-63和HOS骨肉瘤细胞的血小板聚集活性至少部分取决于肿瘤细胞表面相关的血小板反应蛋白，并提出血小板与骨肉瘤细胞的相互作用可能通过与特定血小板膜受体的相互作用而发生。在本研究中，通过使用多种血小板疾病来研究MG-63和HOS细胞的血小板聚集活性。当添加到正常富含血小板的血浆中时，两种骨肉瘤细胞系均诱导出双相血小板聚集反应，而当添加到灰色血小板（α-颗粒蛋白缺乏）和阿司匹林处理的血小板中时，聚集的第二阶段不存在。来自两名无关的I型Glanzmann血小板无力症（糖蛋白（GP）GPIIb/IIIa缺乏）患者的血小板与骨肉瘤细胞根本不聚集。使用来自三名Bernard-Soulier综合征（GPIb/IX缺乏）患者的巨大血小板，与正常大小的血小板和来自一名May-Hegglin异常（无膜GP缺陷）患者的巨大血小板相比，MG-63和HOS细胞诱导的聚集反应是单相且可逆的。由于在止血过程中GPIb作为血管性血友病因子的受体，因此还对两名血浆血管性血友病因子浓度低的患者（I型血管性血友病）在输注去氨-D-精氨酸血管加压素前后的富含血小板血浆进行了聚集实验。在去氨-D-精氨酸血管加压素处理前后，MG-63和HOS细胞均诱导双相血小板聚集，而血管性血友病因子与血小板的瑞斯托菌素依赖性结合仅在去氨-D-精氨酸血管加压素处理后发生。用针对GPIb的血管性血友病因子结合域的单克隆抗体SZ-2对正常富含血小板的血浆进行预孵育，并不抑制骨肉瘤细胞的血小板聚集活性，而抗GPIb抗体SZ-2确实抑制瑞斯托菌素诱导的血小板凝集。此外，抗GPIX抗体不影响血小板与骨肉瘤细胞的相互作用。总之，我们的数据表明，人骨肉瘤细胞血小板聚集活性的第一阶段是由这些肿瘤细胞与血小板膜GPIIb/IIIa的相互作用引发的，而第二阶段，即使血浆血管性血友病因子缺乏，也涉及血小板膜GPIb以及血小板α-颗粒蛋白在膜介导事件中的参与，使聚集不可逆。
