Screening and identification of a renal carcinoma specific peptide from a phage display peptide library

BACKGROUND: Specific peptide ligands to cell surface receptors have been extensively used in tumor research and clinical applications. Phage display technology is a powerful tool for the isolation of cell-specific peptide ligands. To screen and identify novel markers for renal cell carcinoma, we evaluated a peptide that had been identified by phage display technology. METHODS: A renal carcinoma cell line A498 and a normal renal cell line HK-2 were used to carry out subtractive screening in vitro with a phage display peptide library. After three rounds of panning, there was an obvious enrichment for the phages specifically binding to the A498 cells, and the output/input ratio of phages increased about 100 fold. A group of peptides capable of binding specifically to the renal carcinoma cells were obtained, and the affinity of these peptides to the targeting cells and tissues was studied. RESULTS: Through a cell-based ELISA, immunocytochemical staining, immunohistochemical staining, and immunofluorescence, the Phage ZT-2 and synthetic peptide ZT-2 were shown to specifically bind to the tumor cell surfaces of A498 and incision specimens, but not to normal renal tissue samples. CONCLUSION: A peptide ZT-2, which binds specifically to the renal carcinoma cell line A498 was selected from phage display peptide libraries. Therefore, it provides a potential tool for early diagnosis of renal carcinoma or targeted drug delivery in chemotherapy.