【摘要】 目的 :利用噬菌体随机肽库 ,体内筛选可与胃癌移植瘤血管内皮细胞特异结合的多肽片段 ,为肿瘤的血管抑制治疗提供有效的方法和手段。方法 :采用肾包膜下移植法 (SRCA) ,建立免疫抑制小鼠肾包膜下人胃癌移植瘤模型。在小鼠体内对噬菌体十二肽库进行 4轮淘筛 ,回收移植瘤和对照组织 (脑 )中的噬菌体并滴定计数。同时 ,用免疫组织化学染色法 ,检测噬菌体在移植瘤组织中的分布情况。结果 :与胃癌移植瘤血管特异结合的噬菌体得到富集 ,为对照组织 (脑 )的 3.4倍。随机挑取单个克隆测序鉴定 ,发现十二肽YESIRIGVAPSQ的出现次数最多 ,免疫组化染色显示 ,噬菌体注入小鼠尾静脉5min后 ,定位于移植瘤血管的内皮细胞。向小鼠体内单独注入呈现十二肽YESIRIGVAPSQ的噬菌体 ,从胃癌移植瘤组织回收的噬菌体数量为对照组织 (脑 )的 4 .2倍 ,肺的 4 .9倍 ,心脏的 5 .4倍。结论 :筛选到的模拟短肽YESIRIGVAPSQ ,有可能成为肿瘤血管靶向治疗的有效工具。体内淘筛噬菌体随机肽库 ,筛选与靶器官血管内皮细胞特异结合的短肽是可行的 ,具有推广和应用价值。更多还原

【Abstract】 AIM: To screen in vivo from a phage displayed peptide library polypeptide fragments specific binding to vascular endothelial cells of gastric cancer xenografts, so as to provide for anti angiogenesis therapy of tumor. METHODS: Immunosupressed mice models for human gastric cancer xenografts were established by subrenal capsular assay (SRCA). The 12 peptide library was panned through 4 rounds. Phages were recovered and titrated from tumor xenografts and control tissue (brain). The distribution of phage were detected in transplanted tumor tissues by immunohistochemical staining. RESULTS: Phage homing to gastric cancer xenografts were enriched through four rounds of panning, being 3.4 fold of that recovered from brain tissue. Peptide sequences were characterized for randomly picked up clones and the peptide sequence YESIRIGVAPSQ appeared most frequently. Immunohistochemical staining for the homing phage revealed a specific vascular endothelial cell localization in gastric cancer xenografts 5 min after injection of the enriched phages. When the specific phage individually tested, the phage recovered from gastric cancer xenografts were as 4.2 times as those from control tissue (brain), as 4.9 times as those from lung, as 5.4 times as those from heart. CONCLUSION: The tumor specific homing peptides may provide a effective tool for targeting tumor vasculature in anti angiogenesis therapy of cancer. The in vivo selection technique in this study was feasible and applicable to screening peptides homing to vascular endothelial cells.更多还原