Carbohydrate distribution in endothelial cells from various organs in relation to the reactivity with blood platelets

细胞表面糖组分由于其在癌症转移过程中的细胞间相互作用中的关键作用而逐渐获得普遍认可。此外，据报道，具有增加的凝集性的血小板参与体内和体外的转移。使用肝定植小鼠结肠癌（结肠26）细胞，我们最近发现，肿瘤细胞附着到培养的肝窦内皮细胞仅在PRP（富血小板血浆）的存在下。在与PRP孵育的最初几分钟内，大多数肿瘤细胞不是直接粘附在内皮细胞上，而是通过聚集的血小板介导的。此外，几乎所有附着在内皮细胞上的癌细胞都显示出ECA（刺桐凝集素）阳性染色，而来自原始结肠26细胞悬液的细胞中超过一半的细胞对ECA染色呈阴性。这些结果表明，肿瘤细胞和血小板之间的相互作用是建立转移的重要步骤，并且某些糖结构应该参与癌细胞和血小板之间的相互作用。

Cell surface sugar components have progressively conquered universal approval for their key roles in cell-to-cell interaction during the process of cancer metastasis. Also platelets, provided with increased agglutinability, have been reported to be involved in the metastasis both in vivo and in vitro. Using liver-colonizing mouse colon carcinoma (colon 26) cells, we recently revealed that the tumor cells were attached to cultured hepatic sinusoidal endothelial cells only in the presence of PRP (platelet-rich-plasma). Most of tumor cells were attached to endothelial cells not directly but mediated by the aggregated platelets during the first few minites of incubation with PRP. In addition, almost all the cancer cells which were attached to the endothelial cells showed positive staining with ECA (Erythrina crystagalli agglutinin), whereas more than half of cells derived from the original colon 26 cell suspension were negative for ECA staining. These results indicate that interaction between tumor cells and platelets is an important step for the establishment of metastasis, and that certain sugar structures should be involved in the interactions between carcinoma cells and platelets.