A dodecapeptide EDIKPKTSLAFR ligand targeting CEN-1 human nasopharyngeal carcinoma (NPC) was identified by in vivo phage display. Two tridecapeptides and their derivatives, named YR13 (YEDIKPKTSLAFR), EY13 (EDIKPKTSLAFRY), EY13-NH2(EDIKPKTSLAFRY-NH2) and Fmoc-YR13 (Fmoc-YEDIKPKTSLAFR), were synthesized and radiolabeled with 131I. The stability in vitro, biodistribution and tissue distribution of selected phage particles in mice bearing NPC tumor were determined, and plasma metabolites analysis of radiolabeled peptides was carried out. Although Fmoc and NH2 groups could protect the peptide from deiodination, only Fmoc group inhibited the binding of Fmoc-YR13 to NPC tumors. The compound EY13-NH2, the C-terminal amide of peptide EY13, had the greatest serum stability, the least deiodination, and showed favorable tumor/blood ratios. The selected phage particles (phage 3 or phage 5) were more concentrated in NPC tumors than the control phage (initial phage display peptide library). EY13 could also inhibit the binding of selected phage particles to tumors. The results indicated that EDIKPKTSLAFR was a good candidate in diagnostic and therapeutic NPC.

利用体内噬菌体展示技术鉴定了一种靶向人鼻咽癌CEN-1的十二肽EDIKPKTSLAFR配体。合成了两个三肽及其衍生物YR13 （YEDIKPKTSLAFR）、EY13 （EDIKPKTSLAFRY）、EY13- nh2 （EDIKPKTSLAFRY- nh2）和Fmoc-YR13 (Fmoc-YEDIKPKTSLAFR)，并用131I进行放射性标记。测定所选噬菌体颗粒在鼻咽癌小鼠体内的体外稳定性、生物分布和组织分布，并进行放射性标记肽的血浆代谢物分析。虽然Fmoc和NH2组可以保护肽不受脱碘作用，但只有Fmoc组抑制了Fmoc- yr13与NPC肿瘤的结合。化合物EY13- nh2是肽EY13的c端酰胺，其血清稳定性最好，脱碘作用最小，肿瘤/血比较好。选择的噬菌体颗粒（噬菌体3或噬菌体5）在鼻咽癌肿瘤中的浓度高于对照噬菌体（初始噬菌体展示肽库）。EY13还能抑制选定的噬菌体颗粒与肿瘤的结合。结果表明，EDIKPKTSLAFR在鼻咽癌的诊断和治疗中具有良好的候选价值。