A multifunctional peptide for targeted imaging and chemotherapy for nasopharyngeal and breast cancers.

UNLABELLED: The L-peptide plays a role as a universal ligand binding specifically to nasopharyngeal carcinoma (NPC) and other cancers but not normal cells. It was used to link iron oxide nanoparticles, and injected intravenously to SCID mice bearing NPC and breast cancer xenografts for MR analysis, and showed significant change of MR signal intensity in the xenograft regions. Using this conjugate as a ligand to localize the L-peptide targeted protein in the cancer surgical specimens, a clear reaction product was identified in the tumor cells of both cancer types. If the L-peptide-linked-liposomal doxorubicin was used to treat the SCID mice bearing other NPC or breast cancer xenograft, a high efficacy of chemotherapy with minimal adverse effect was observed. In conclusion, the L-peptide has a considerable potential for clinical usage for targeted imaging, peptide histochemical localization of targeted protein, and targeted chemotherapy for different cancer types.

FROM THE CLINICAL EDITOR: Targeted chemotherapy to cancer cells will enable maximum drug delivery but minimal systemic side effects. In this article, the authors identified a protein, L-peptide, on tumor cells. They also subsequently confirmed the specificity of this protein in animal experiments using iron oxide nanoparticles. The discovery of this marker could lead to future development of better chemotherapy.