Phage display selection of peptides that inhibit metastasis ability of gastric cancer cells with high liver-metastatic potential.

Organ-specific metastasis is an important character of cancer cells. Cancer cells that can metastasize to a special organ were thought to have different proteins in cell membrane, which might have potential utility as diagnostic markers and therapeutic targets. In the present work, based on high liver-metastatic gastric cancer cells, XGC9811-L, a screening approach with phage displayed peptide library, was successfully used to isolate 8-mer peptide ligands binding to the target cells. The phage20 had the highest binding efficiency to XGC9811-L cells, which also displayed remarkable cell specificity. Peptide20 that was displayed on phage20 could suppress the motility and invasion of XGC9811-L significantly. The adhesive ability of XGC9811-L to collagen IV was also inhibited by peptide20. Furthermore, phage20 could significantly reduce the incidence of liver metastasis of gastric cancer transplanted into nude mice and was also beneficial for the reduction the number of metastatic nodules in the liver. In conclusion, the phage display is an effective method to screen for the new molecules associated with organ-specific metastasis. The selected peptide20 can reverse the liver metastasis behavior of the gastric cancer cells.