Menter D G, Steinert B W, Sloane B F, Taylor J D, Honn K V
Cancer Res. 1987 May 1;47(9):2425-32.
We have developed a new in vitro model system to examine tumor cell-platelet-endothelial cell interactions under dynamic conditions. Using the same model, we can determine endogenous eicosanoid metabolism and alterations in the prostacyclin-thromboxane A2 balance associated with interactions among tumor cells, platelets, and endothelial cells. The model consisted of cloned rat aortic endothelial cells grown on gelatin microcarrier beads under dynamic conditions (i.e., spinner culture). Interactions of these endothelial cells with platelets (heparinized rat platelet rich plasma) and/or tumor cells (rat Walker 256 carcinosarcoma) were assessed in an aggregometer. Gelatin beads alone or microcarrier grown endothelial cells did not elicit spontaneous aggregation of platelet rich plasma over a time period of 30 min. Microcarrier grown endothelial cells inhibited tumor cell induced platelet aggregation in a dose dependent fashion (i.e., depending on endothelial cell number). The ability of microcarrier grown endothelial cells to inhibit tumor cell induced platelet aggregation depended on endogenous production of prostacyclin. This conclusion is based on the following results: an increased number of microcarrier grown endothelial cells caused a prolongation of the aggregation lag time; an increased number of microcarrier grown endothelial cells caused a proportionate increase in 6-keto-prostaglandin F1 alpha concentration; an increased number of microcarrier grown endothelial cells was inversely correlated with thromboxane A2 production by platelets; indomethacin pretreatment of microcarrier grown endothelial cells caused a decrease in prostacyclin production and therefore overcame the associated inhibition of tumor cell induced platelet aggregation; and the inhibition of tumor cell induced platelet aggregation in the presence of endogenous prostacyclin produced by microcarrier grown endothelial cells was the same as that observed in the presence of exogenous prostacyclin. Scanning electron microscopy of aggregometry samples revealed: little or no platelet or tumor cell adhesion to gelatin beads alone, a low basal adhesion of tumor cells to microcarrier grown endothelial cells, and large aggregates of platelets and tumor cells located primarily at gaps in the monolayer of indomethacin treated microcarrier grown endothelial cells. This new in vitro model provides a method for examining the effects of eicosanoid metabolism by endothelial cells on tumor cell-platelet-endothelial cell interactions under dynamic conditions.
我们开发了一种新的体外模型系统，用于在动态条件下研究肿瘤细胞-血小板-内皮细胞的相互作用。使用相同的模型，我们可以确定内源性类花生酸代谢以及与肿瘤细胞、血小板和内皮细胞之间相互作用相关的前列环素-血栓素A2平衡的变化。该模型由在动态条件下（即旋转培养）生长在明胶微载体珠上的克隆大鼠主动脉内皮细胞组成。在聚集仪中评估这些内皮细胞与血小板（肝素化大鼠富含血小板血浆）和/或肿瘤细胞（大鼠Walker 256癌肉瘤）的相互作用。单独的明胶珠或微载体生长的内皮细胞在30分钟内不会引起富含血小板血浆的自发聚集。微载体生长的内皮细胞以剂量依赖性方式（即取决于内皮细胞数量）抑制肿瘤细胞诱导的血小板聚集。微载体生长的内皮细胞抑制肿瘤细胞诱导的血小板聚集的能力取决于前列环素的内源性产生。这一结论基于以下结果：微载体生长的内皮细胞数量增加导致聚集滞后时间延长；微载体生长的内皮细胞数量增加导致6-酮-前列腺素F1α浓度成比例增加；微载体生长的内皮细胞数量增加与血小板产生的血栓素A2呈负相关；对微载体生长的内皮细胞进行吲哚美辛预处理会导致前列环素产生减少，从而克服对肿瘤细胞诱导的血小板聚集的相关抑制作用；并且在微载体生长的内皮细胞产生的内源性前列环素存在下对肿瘤细胞诱导的血小板聚集的抑制作用与在外源性前列环素存在下观察到的抑制作用相同。聚集仪样品的扫描电子显微镜显示：单独的明胶珠上几乎没有或没有血小板或肿瘤细胞粘附，肿瘤细胞对微载体生长的内皮细胞的基础粘附力较低，并且血小板和肿瘤细胞的大聚集体主要位于吲哚美辛处理的微载体生长的内皮细胞单层的间隙处。这种新的体外模型提供了一种方法，用于在动态条件下研究内皮细胞类花生酸代谢对肿瘤细胞-血小板-内皮细胞相互作用的影响。
