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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。
OBJECTIVE: To screen peptide fragments that can specifically bind to the vascular endothelial cells of gastric cancer xenografts using phage random peptide library in vivo to provide an effective method and means for vascular suppression therapy of tumors. Methods: The model of human gastric cancer xenograft in immunosuppressed mice was established by subrenal capsule transplantation (SRCA). Phage-didecapeptide pools were panned for 4 rounds in mice and the phage in the xenografts and control tissues (brains) were recovered and titrated. At the same time, the distribution of phage in the xenografts was detected by immunohistochemical staining. Results: The phage that specifically bound to the vascular tumor xenografts were enriched 3.4 times as much as the control tissue (brain). The results of single clone sequencing showed that YESIRIGVAPSQ appeared most frequently. Immunohistochemical staining showed that the phage were localized in the vascular endothelial cells of the xenografts after 5 min of injection into the tail vein of mice. The mice were injected with phage containing the dodecapeptide YESIRIGVAPSQ alone. The number of phage recovered from gastric cancer xenografts was 4.2 times that of the control tissues (brain), 4.9 times the lungs, and 5.4 times the heart. CONCLUSION: The selected mimic peptide YESIRIGVAPSQ may be an effective tool for tumor vascular targeted therapy. Screening phage random peptide library in vivo, screening and target organ vascular endothelial cells specific binding of short peptides is feasible, with the promotion and application value.