抗胃肠粘液骨架蛋白单抗和裸鼠移植人胃癌体内示踪定位分布研究

应用人工合成人胃肠粘液骨架蛋白之序列七肽片段,评价系列抗胃肠癌单抗之抗原决定簇。结果,首次发现一个抗人胃肠粘液的单克隆抗体,其抗原决定簇为富含苏氨酸的粘液分子骨架蛋白的七肽片段ITTTTTV。并进一步采用两株组织类型不同的移植人胃癌组织裸鼠模型,经体外扫描方法,追踪观察了~(131)I标记该单抗GL-013在荷瘤裸鼠体内定位移植瘤能力。经腹腔注入~(131)I标记GL-013后第3天开始,两株移植瘤即能被清晰地显示出来,且在72h取出鼠内脏后的扫描图中仍可见扫描图中的高放射性浓聚区,而注入~(131)I标记正常鼠γ球蛋白,移植瘤则未被显示;第9天时两株荷瘤裸鼠的实验组与对照组的T/NT值均呈明显差异。表明抗胃肠粘液之单抗GL-013在荷瘤裸鼠体内是定位于两株人胃癌移植瘤组织的。提示GL-013单抗可能适于对不同组织类型胃癌的放射免疫显像。

MONOCLONAL ANTIBODY TO GASTROINTESTINAL MUCIN AND ITS RADIOIMMUNOLOCALIZATION IN HUMAN GASTRIC CARCINOMA XENOGRAFTS

The epitopes defined by a panel of anti-human gastric carcinoma monoclonal antibodies were detected for synthetic peptides with sequences based upon that reported for the protein core of a human gastrointestinal mucin. A theonine-rich p Deptide (ITTTTTV)epitope expressed within the protein of gastrointestinal mucin was defined. Radioiodinated monocl onal antibody GL-013 was injected intraperitoneally into nude mice bearing human gastric carcinoma xenografts SY86B and SY86D. Best contrast was obtained between days of 3 and 7 after injection of radiolabelled McAb. In confirmation of imaging results, ~(13)I-GL-013 preferentially localized in tumor tissue compared with normal tissue. These results demonstrate that MAB GL-013 does localize to the xenografts SY86D and suggest the possible clinical application of MAb GL-013 in radioimmunolocalization.