抗结肠癌单抗CL—4对应抗原性质及决定簇的初步分析

本文对本室制备抗结肠癌单克隆抗体CL-4的对应癌相关抗原进行了初步分析,证明该抗原的性质为糖脂和糖蛋白;其抗原决定簇为一种含涎酸的碳水化合物结构,可能是结肠癌细胞膜上的神经节苷酯和癌细胞内的粘液性大分子糖蛋白,其分子量分别为115-205KD和256KD。并研究了CL-4和CA19-9两种单抗所作用的对应抗原决定簇是否相同。根据添加指数为28％,此值稍大于25％,表明这两种单抗所识别抗原决定簇不完全相同。该抗原可能是一种新的含涎酸的结肠癌标志物。

Analysis of The Biochemical Property of Epitope of the Antigen Related to Colorectal Cancer by Monoclonal Antibody CL-4

Characterization of the CL-4 related antigen was studied with different immunochemical methods. Results showed that: McAb CL-4 reacted with both glycoli-pid and glycoprotein fraction of the colon cancer cell line LS-174T. Immunostaining after SDS-PAGE and Western blot of the colon cancer cell membrane or cytosol showed that CL-4 reacted predominately with mucin type high molecular weight molecules (256 KD and 115-205KD) . The immune-reactivity was deminished when antigen was first treated with neuraminidase, but unaffected after boiling or trypsin digestion. This indicates that CL-4 recognize epitopes involving sialic acid on the carbohydrate moieties of the colon cancer cells. By additivity test and comparison with the distribution of other McAbs, it is proposed that the epitope of CL-4 Antigen is distinct from that of Sialo-Lea, Sialo-Lex and Sialo-Tn.