Nitta K, Ozaki K, Ishikawa M, Furusawa S, Hosono M, Kawauchi H, Sasaki K, Takayanagi Y, Tsuiki S, Hakomori S
Cancer Research Institute, Tohoku College of Pharmaceutical Sciences, Sendai, Japan.
Cancer Res. 1994 Feb 15;54(4):920-7.
Two frog egg lectins [Rana catesbeiana lectin (SBL-C) and Rana japonica lectin] preferentially agglutinate a large variety of human and animal tumor cells but not blood cells, lymphocytes, or fibroblasts. These lectins belong to the superfamily of pyrimidine base-specific RNases. The two lectins bound to a heparin-Sepharose column and were eluted from the column by an increase of NaCl molarity. Both their tumor cell-agglutinating activity and RNase activity were inhibited by heparin, and also by polyamines, such as spermine. Both lectins inhibited P388 leukemia cell proliferation. The inhibitory activity of SBL-C was blocked by addition of heparin. SBL-C inhibited protein synthesis by P388 cells, but RNase A did not. No lectin-induced antiproliferative effect was observed after sialidase treatment of cells. The antiproliferative activity of SBL-C was also inhibited by ammonium chloride treatment. These results suggest that internalization of the lectins by lectin receptor (sialoglycoconjugate)-mediated endocytosis is followed by cell death due to inhibition of protein synthesis. Administration of SBL-C i.p. delayed time to death in mice receiving i.p. transplants of Sarcoma 180 and Mep II cells.
两种蛙卵凝集素[牛蛙凝集素（SBL-C）和日本林蛙凝集素]能优先凝集多种人类和动物肿瘤细胞，但不凝集血细胞、淋巴细胞或成纤维细胞。这些凝集素属于嘧啶碱基特异性核糖核酸酶超家族。这两种凝集素与肝素-琼脂糖柱结合，并通过增加氯化钠摩尔浓度从柱上洗脱下来。它们的肿瘤细胞凝集活性和核糖核酸酶活性均受到肝素以及多胺（如精胺）的抑制。两种凝集素均抑制P388白血病细胞的增殖。加入肝素可阻断SBL-C的抑制活性。SBL-C抑制P388细胞的蛋白质合成，但核糖核酸酶A无此作用。细胞经唾液酸酶处理后未观察到凝集素诱导的抗增殖效应。氯化铵处理也抑制了SBL-C的抗增殖活性。这些结果表明，凝集素通过凝集素受体（唾液酸糖缀合物）介导的内吞作用内化后，会因蛋白质合成受到抑制而导致细胞死亡。腹腔注射SBL-C可延长接受肉瘤180和Mep II细胞腹腔移植的小鼠的死亡时间。
