Discovery of an SSTR2-Targeting Maytansinoid Conjugate (PEN-221) with Potent Activity in Vitro and in Vivo
摘要:
Somatostatin receptor 2 (SSTR2) is frequently overexpressed on several types of solid tumors, including neuroendocrine tumors and small-cell lung cancer. Peptide agonists of SSTR2 are rapidly internalized upon binding to the receptor and linking a toxic payload to an SSTR2 agonist is a potential method to kill SSTR2-expressing tumor cells. Herein, we describe our efforts towards an efficacious SSTR2-targeting cytotoxic conjugate; examination of different SSTR2-targeting ligands, conjugation sites, and payloads led to the discovery of 22 (PEN-221), a conjugate consisting of microtubule-targeting agent DM1 linked to the C-terminal side chain of Tyr(3)-octreotate. PEN-221 demonstrates in vitro activity which is both potent (IC50 = 10 nM) and receptor-dependent (IC50 shifts 90-fold upon receptor blockade). PEN-221 targets high levels of DM1 to SSTR2-expressing xenograft tumors, which has led to tumor regressions in several SSTR2-expressing xenograft mouse models. The safety and efficacy of PEN-221 is currently under evaluation in human clinical trials.
Peptide Backbone Composition and Protease Susceptibility: Impact of Modification Type, Position, and Tandem Substitution
作者:Halina M. Werner、Chino C. Cabalteja、W. Seth Horne
DOI:10.1002/cbic.201500312
日期:2016.4.15
Modification station: We report here a systematic comparison of the enzymatic protection imparted by four backbonemodifications commonly employed in the design of protease‐stable analogues of peptides and proteins. These results promise to inform ongoing work to develop biostable mimics with increasingly sophisticated structures and functions.
Targeting Extracellular Cyclophilin A via an Albumin‐Binding Cyclosporine A Analogue
作者:Si‐Yu Liu、Qing‐Zhou Zhang、Min‐Qiang Hu、Feng‐Xia Li、Jia‐Miao Fu、Zhen‐Dong Zhu、Qin‐Kai Li、Zhen Yang、Jun‐Min Quan
DOI:10.1002/cmdc.202100526
日期:2021.12.14
Extracellularlytargeted: we developed an albumin-binding CsA analogue, 4MCsA, modified by a thiol-reactive maleimide group. 4MCsA readily covalently binds to albumin residue Cys34 with the maleimide group, and is restricted extracellularly. 4MCsA has similar binding affinity for CypA as that of CsA, yet is devoid of immunosuppressive capacity and cellular toxicity. 4MCsA exhibits potent inhibition
Reinventing Hsp90 Inhibitors: Blocking C-Terminal Binding Events to Hsp90 by Using Dimerized Inhibitors
作者:Yen Chin Koay、Hendra Wahyudi、Shelli R. McAlpine
DOI:10.1002/chem.201603464
日期:2016.12.19
promising anticancer target. Classical inhibitors that block the binding of adenine triphosphate (ATP) to the N‐terminus of Hsp90 are highly toxic to cells and trigger a resistance mechanism within cells. This resistance mechanism comprises a large increase in prosurvival proteins, namely, heatshock protein 70 (Hsp70), heatshock protein 27 (Hsp27), and heatshock factor 1 (HSF‐1). Molecules that modulate
Solid-Phase Synthesis of <i>N</i>-Nosyl- and <i>N</i>-Fmoc-<i>N</i>-Methyl-α-amino Acids
作者:Maria Luisa Di Gioia、Antonella Leggio、Angelo Liguori、Francesca Perri
DOI:10.1021/jo070075m
日期:2007.5.1
convenient and simple solid-phasesynthesis of N-nosyl-N-methyl-α-amino acids and N-Fmoc-N-methyl-α-amino acids, important building blocks for the synthesis of conformationally restricted and protease-resistant natural peptides and peptide analogues. The methodology involves the use of 2-chlorotrityl chloride resin to temporarily protect the carboxylic group of α-amino acids and of diazomethane as
Converting polar cyclic peptides into membrane permeable molecules using <i>N</i>
-methylation
作者:Leo L. H. Lee、Laura K. Buckton、Shelli R. McAlpine
DOI:10.1002/pep2.24063
日期:2018.5
Described are the design, synthesis, and biologicalevaluation of 5 N‐methylated analogs that are based on a lead drug structure LB51. LB51 is a cyclic pentapeptide that inhibits heat shock protein 90 and although a potent inhibitor of the protein function, it has poor cell permeability. Introduction of an N‐methyl moiety at each amino acid produces 5 analogs of LB51, where all 5 show significantly