Identification of Novel Medulloblastoma Cell-Targeting Peptides for Use in Selective Chemotherapy Drug Delivery

• Published in: Journal of medicinal chemistry 2020-03, Vol.63 (5), p.2181-2193
• Main Authors: Tjandra, Kristel C, McCarthy, Nigel, Yang, Lu, Laos, Alistair J, Sharbeen, George, Phillips, Phoebe A, Forgham, Helen, Sagnella, Sharon M, Whan, Renee M, Kavallaris, Maria, Thordarson, Pall, McCarroll, Joshua A
• Format: Article
• Language: English
• ISSN: 0022-2623; 1520-4804
• DOI: 10.1021/acs.jmedchem.9b00851

Medulloblastoma is a malignant brain tumor diagnosed in children. Chemotherapy has improved survival rates to approximately 70%; however, children are often left with long-term treatment side effects. New therapies that maintain a high cure rate while reducing off-target toxicity are required. We describe for the first time the use of a bacteriophage-peptide display library to identify heptapeptides that bind to medulloblastoma cells. Two heptapeptides that demonstrated high [E1-3 (1)] or low [E1-7 (2)] medulloblastoma cell binding affinity were synthesized. The potential of the peptides to deliver a therapeutic drug to medulloblastoma cells with specificity was investigated by conjugating E1-3 (1) or E1-7 (2) to doxorubicin (5). Both peptide–drug conjugates were cytotoxic to medulloblastoma cells. E1-3 doxorubicin (3) could permeabilize an in vitro blood–brain barrier and showed a marked reduction in cytotoxicity compared to free doxorubicin (5) in nontumor cells. This study provides proof-of-concept for developing peptide–drug conjugates to inhibit medulloblastoma cell growth while minimizing off-target toxicity.