Systemic combinatorial peptide selection yields a non-canonical iron-mimicry mechanism for targeting tumors in a mouse model of human glioblastoma

• Published in: The Journal of clinical investigation 2011-01, Vol.121 (1), p.161-173
• Main Authors: Staquicini, Fernanda I, Ozawa, Michael G, Moya, Catherine A, Driessen, Wouter H P, Barbu, E Magda, Nishimori, Hiroyuki, Soghomonyan, Suren, Flores, 2nd, Leo G, Liang, Xiaowen, Paolillo, Vincenzo, Alauddin, Mian M, Basilion, James P, Furnari, Frank B, Bogler, Oliver, Lang, Frederick F, Aldape, Kenneth D, Fuller, Gregory N, Höök, Magnus, Gelovani, Juri G, Sidman, Richard L, Cavenee, Webster K, Pasqualini, Renata, Arap, Wadih
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Antineoplastic Agents - chemistry; Antineoplastic Agents - pharmacology; Biomedical research; Blood-brain barrier; Blood-Brain Barrier - drug effects; Brain cancer; Brain Neoplasms - drug therapy; Brain Neoplasms - genetics; Brain Neoplasms - metabolism; Carrier Proteins - metabolism; Cell Line, Tumor; Cell receptors; Development and progression; Disease Models, Animal; Female; Glioblastoma - drug therapy; Glioblastoma - genetics; Glioblastoma - metabolism; Glioblastoma multiforme; Humans; Iron - metabolism; Kinases; Ligands; Mice; Mice, Inbred BALB C; Mice, Nude; Models, Molecular; Molecular Mimicry; Molecular Sequence Data; Oligopeptides - chemistry; Oligopeptides - genetics; Oligopeptides - pharmacology; Peptide Library; Peptides; Permeability; Physiological aspects; Proteins; Receptors, Transferrin - metabolism; Technical Advance; Transferrin - metabolism; Tumors; Xenograft Model Antitumor Assays
• ISSN: 0021-9738; 1558-8238
• DOI: 10.1172/JCI44798

The management of CNS tumors is limited by the blood-brain barrier (BBB), a vascular interface that restricts the passage of most molecules from the blood into the brain. Here we show that phage particles targeted with certain ligand motifs selected in vivo from a combinatorial peptide library can cross the BBB under normal and pathological conditions. Specifically, we demonstrated that phage clones displaying an iron-mimic peptide were able to target a protein complex of transferrin and transferrin receptor (TfR) through a non-canonical allosteric binding mechanism and that this functional protein complex mediated transport of the corresponding viral particles into the normal mouse brain. We also showed that, in an orthotopic mouse model of human glioblastoma, a combination of TfR overexpression plus extended vascular permeability and ligand retention resulted in remarkable brain tumor targeting of chimeric adeno-associated virus/phage particles displaying the iron-mimic peptide and carrying a gene of interest. As a proof of concept, we delivered the HSV thymidine kinase gene for molecular-genetic imaging and targeted therapy of intracranial xenografted tumors. Finally, we established that these experimental findings might be clinically relevant by determining through human tissue microarrays that many primary astrocytic tumors strongly express TfR. Together, our combinatorial selection system and results may provide a translational avenue for the targeted detection and treatment of brain tumors.