Targeted Therapy of Central Nervous System Acute Lymphoblastic Leukemia with an Integrin a 6-Targeted Self-Assembling Proapoptotic Nanopeptide

There is currently no effective targeted therapeutic strategy for the treatment of central nervous system acute lymphoblastic leukemia (CNS-ALL). Integrin a6 is considered a potential target for CNS-ALL diagnosis and therapy because of its role in promoting CNS-ALL disease progression. The targeted peptide D(RWYD) (abbreviated RD), with nanomolar affinity to integrin a6 was identified by peptide scanning techniques such as alanine scanning, truncation, and D-substitution. Herein, we developed a therapeutic nanoparticle based on the integrin a6-targeted peptide for treating CNS-ALL. The self-assembled proapoptotic nanopeptide D(RWYD)-D(KLAKLAK)2-GD(FFY) (abbreviated RD-KLA-Gffy) contains the integrin a6-targeted peptide RD, the well-known proapoptotic peptide D(KLAKLAK)2 (abbreviated KLA), and the self-assembling tetrapeptide GD(FFY) (abbreviated Gffy). The functional mechanism of RD-KLA-Gffy is clarified using different experiments. Our results demonstrate that RD-KLA-Gffy is highly enriched in CNS-ALL lesions and induces tumor cell apoptosis, thus reducing CNS-ALL disease burden and prolonging the survival of CNS-ALL mice without obvious toxicity. Moreover, the combined use of RD-KLA-Gffy and methotrexate (MTX) shows a potent antitumor effect in treating CNS-ALL, indicating that RD-KLA-Gffy plays an important role in suppressing CNS-ALL progression either as a single agent or in combination with MTX, which shows promise for application in CNS-ALL therapy. (c) 2023 THE AUTHORS. Published by Elsevier LTD on behalf of Chinese Academy of Engineering and Higher Education Press Limited Company. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).