中文摘要：

采用离子交换柱分离分子量小于1．0kD的新生牛肝提取液，得到9份样品．在体外抑制肿瘤细胞增殖的基础上，选用体外抑瘤明显的离子交换柱层析获得的（5）组分进行体内对荷S-180肉瘤小鼠的肉瘤生长抑制实验．并从白细胞数、胸腺指数和脾指数三个角度分析了低分子抑瘤物对荷瘤小鼠免疫功能的影响；同时用斑点印记法，比较荷瘤前后重要脏器和肉瘤细胞内p27／kipl细胞周期调控蛋白表达水平的变化．实验结果表明低分子新生牛肝提取液和经离子交换柱层析分离得到的（5）组分对荷S-180肉瘤小鼠的肉瘤生长有明显的抑制作用，实验同时发现来源于新生牛肝中的低分子抑瘤物，可通过增强荷瘤小鼠的免疫力，升高肉瘤细胞中的p27／kipl蛋白表达水平的方式抑制肉瘤细胞的增殖，阻碍瘤细胞向正常组织的浸润和转移．

英文摘要：

Nine low molecular weight （〈1.0 kD） components were separated from the filtrate of the newborn calf liver by ion-exchange chromatographic column. The components were analyzed by thin-layer chromatography and component（5 ） showed significant inhibitory effects on the proliferation of HL-60 and MCF-7 in vitro and on sarcoma of the mice bearing sarcoma- 180. The quantitative studies of white blood cells, thymus index and spleen index before and after treatment showed an immunoprotective effect of the filtrate of the newborn calf liver and the component（5） on the mice bearing sarcoma-180. Results of the dot blotting demonstrated that the low molecular weight tumor suppressor could regulate the level of cell cycle protein p27/kipl of the sarcoma and block the immerging and transferring of sarcoma to other tissues.