A Novel Peptide Specifically Binding to Nasopharyngeal Carcinoma For Targeted Drug Delivery

Nasopharyngeal carcinoma (NPC) is a common cancer among Chinese living in southern China, Taiwan, and Singapore. The 5-year survival rate in the early stage of NPC has been reported as high as 90 to 95% with the use of radiotherapy, but in the advanced cases, even with the use of both chemotherapy and radiotherapy, the survival rate is still <50%. To improve the survival rate, we identify a 12-mer peptide (l-peptide) specifically binding to NPC cells with a phage displayed random peptide library. The l-phage and synthetic l-peptide bound to the tumor cell surfaces of most NPC cell lines and biopsy specimens, but not normal nasal mucosal cells, and the l-peptide–linked liposomes containing fluorescent substance (l-peptide-Lipo-HPTS) were capable of binding to and translocating across plasma membranes. l-Peptide–linked liposomes that carried doxorubicin (l-peptide-Lipo-Dox) caused marked cytotoxicity in NPC cells. In SCID mice bearing NPC xenografts, the l-phages specifically bound to the tumor mass, an effect that was inhibited by competition with synthetic l-peptide. In addition, the l-peptide-Lipo-Dox suppressed tumor growth better than Lipo-Dox. These results indicate that the novel l-peptide specifically binds NPC cells and is a good candidate for targeted drug delivery to NPC solid tumors.