利用噬菌体展示技术筛选放射性标记肺癌靶肽YC11及其生物分布

利用体内噬菌体展示技术筛选了肿瘤特异性结合靶肽, 获得了肺腺癌靶肽CSIHYPLSC(YC11)并对其进行了放射性碘标记. 采用反相高效液相色谱技术(RP-HPLC)分离纯化¹³¹I-YC11和对照肽¹³¹I-NGR, 放化纯度大于99%. 在荷人肺腺癌A549裸鼠体内的分布结果表明, ¹³¹I-YC11的肿瘤/血液放射性计数比为0.62, 肿瘤/心脏放射性计数比为2.06, 肿瘤/肺放射性计数比为1.11, 肿瘤/肝脏放射性计数比为0.81, 略高于¹³¹I-NGR的对应值. ¹³¹I-YC11在肿瘤中的摄取值为2.79%ID/g, 与¹³¹I-NGR在肿瘤中的摄取值(1.61%ID/g)相比, ¹³¹I-YC11的肿瘤摄取高于多肽¹³¹I-NGR.

Screening, Radiolabeling and Biodistribution of Lung Tumor-targeting Peptide YC11 by in vivo Phage Display

In vivo phage display was used to isolate tumor-targeting peptides. A cycloheptapeptide CSIHYPLSC(YC11) ligand targeting A549 human lung tumor was identified and radioiodinated. The labeled complex 131I-YC11 and 131I-NGR(control peptide) were isolated and purified by reverse phase high-performance liquid chromatography(RP-HPLC). The radiochemical purity was estimated to be better than 99%. The biodistribution results of 131I-YC11 and control peptide 131I-NGR in mice bearing A549 tumor demonstrated that the tumor-to-blood, tumor-to-heart, tumor-to-lung and tumor-to-liver uptake ratios of 131I-YC11 were 0.62, 2.06, 1.11 and 0.81, respectively, and slightly higher than those of 131I-NGR. The uptake of 131I-YC11 in tumor was 2.79%ID/g, more than that of 131I-NGR(1.61%ID/g). 131I-YC11 was more concentrated in A549 tumor than 131I-NGR. Conclusively, YC11 could be a potential lung cancer targeting agent.