Collard J G, Schijven J F, Bikker A, La Riviere G, Bolscher J G, Roos E
Cancer Res. 1986 Jul;46(7):3521-7.
T-cell hybridomas prepared by fusion of non-invasive non-metastatic BW5147 T-lymphoma cells and activated normal T-cells were found to be highly invasive in vitro and highly metastatic in vivo upon tail vein injection. By prolonged culturing and subcloning, non-invasive, non-metastatic hybrids were selected with modal DNA/cell contents close to the diploid value of both fusion partners. Since normal activated T-cells were invasive in vitro in hepatocyte cultures, these data suggest that invasiveness of the hybrids is derived from the parental normal T-cells and is one of the properties responsible for the metastatic potential of these cells. Analysis of a large panel of T-cell hybrids with fluorescein isothiocyanate conjugated lectins, specific for terminal galactose and/or N-acetylgalactosamine sugar residues, showed an inverse correlation between expression of lectin receptor sites and invasive and metastatic potential of the hybrids. Soybean agglutinin, as well as peanut agglutinin and Ricinus communis agglutinin, reacted strongly with non- or low-invasive hybrids but only weakly with invasive hybrids. The difference in lectin binding between both types of hybrids appeared to be due to masking of receptor sites by sialic acid. Removal of cell surface sialic acid by neuraminidase treatment unmasked the lectin receptor sites of invasive hybrids to the level of the corresponding sites of non- or low-invasive cells. This increase in active lectin binding sites was simultaneously accompanied by a striking decrease of invasiveness to the level of the low-invasive hybrids. Conversely, the blocking of R. communis agglutinin receptors by sialic acid allowed selection of invasive hybrids from segregating cell populations with the toxic lectin R. communis agglutinin. The results taken together indicate that sialylation of particular cell surface carbohydrate residues on the T-cell hybridomas is associated with the invasive and metastatic potential of these hybrids. The reduction of invasive potential after removal of cell surface sialic acid provides further evidence for a functional role of this sugar residue in invasiveness of the T-cell hybrids.
通过将非侵袭性、非转移性的BW5147 T淋巴瘤细胞与活化的正常T细胞融合制备的T细胞杂交瘤，在体外具有高度侵袭性，经尾静脉注射后在体内具有高度转移性。通过长期培养和亚克隆，选择出了非侵袭性、非转移性的杂交瘤，其DNA/细胞含量模式接近两个融合亲本的二倍体值。由于正常活化的T细胞在体外肝细胞培养中具有侵袭性，这些数据表明杂交瘤的侵袭性源自亲本正常T细胞，并且是这些细胞转移潜能的相关特性之一。用异硫氰酸荧光素偶联的凝集素（对末端半乳糖和/或N-乙酰半乳糖胺糖残基具有特异性）对大量T细胞杂交瘤进行分析，结果显示凝集素受体位点的表达与杂交瘤的侵袭和转移潜能呈负相关。大豆凝集素以及花生凝集素和蓖麻凝集素与非侵袭性或低侵袭性杂交瘤反应强烈，但与侵袭性杂交瘤反应较弱。两种类型杂交瘤之间凝集素结合的差异似乎是由于唾液酸对受体位点的掩盖。用神经氨酸酶处理去除细胞表面唾液酸后，侵袭性杂交瘤的凝集素受体位点暴露至非侵袭性或低侵袭性细胞相应位点的水平。活性凝集素结合位点的这种增加同时伴随着侵袭性显著降低至低侵袭性杂交瘤的水平。相反，用唾液酸阻断蓖麻凝集素受体后，可用毒性凝集素蓖麻凝集素从分离的细胞群体中选择侵袭性杂交瘤。综合这些结果表明，T细胞杂交瘤特定细胞表面碳水化合物残基的唾液酸化与这些杂交瘤的侵袭和转移潜能相关。去除细胞表面唾液酸后侵袭潜能的降低为该糖残基在T细胞杂交瘤侵袭性中的功能作用提供了进一步证据。
