骨肉瘤细胞特异性结合短肽的筛选

目的获得与骨肉瘤细胞株os-732特异结合的短肽,作为骨肉瘤靶向治疗的先导化合物。方法以骨肉瘤细胞os-732为靶细胞,成骨细胞为吸附细胞对噬菌体12肽库进行差减筛选,用细胞ELISA、免疫组化鉴定阳性噬菌体克隆并测序。结果经三轮筛选,从随机挑选的20个噬菌体克隆中得到9个能特异性与骨肉瘤细胞os-732结合,而不与正常成骨细胞结合的阳性克隆。但其氨基酸序列无同源性。结论得到多个序列不同的特异性结合骨肉瘤的噬菌体克隆,提示骨肉瘤细胞表面结构复杂,具多个骨肉瘤抗原表位。本实验获得的短肽具有一定的亲合力和肿瘤特异性,为针对不同位点的靶向药物设计提供了实验依据。

Screening of short peptides that bind specifically to osteosarcoma cells by phage-displayed peptide library

Objective To obtain short peptides which bind specifically to osteosarcoma cells os-732 by means of screening from 12 peptide libraries. Methods Osteosarcoma cells os-732 were used as the target cells and osteoblasts as the absorber cells for subtraction biopanning from a 12-mer peptide phage-display library. After 3 rounds of screening, the positive phage clones were identified by cell enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry, and the amino acid sequences were deduced by DNA sequencing. Results Nine positive phage clones screened out of 20 clones showed specific binding with osteosarcoma os-732, but no conserved motif was found in these peptides. Conclusion The specific peptides screened from the phage library may be used as potential candidates as ligands for tumor-targeting therapy. The results also suggested that there are different epitopes on the surface of tumor cells.