Exploiting an Asp-Glu "switch" in glycogen synthase kinase 3 to design paralog-selective inhibitors for use in acute myeloid leukemia.

Abstract

Glycogen synthase kinase 3 (GSK3), a key regulatory kinase in the wingless-type MMTV integration site family (WNT) pathway, is a therapeutic target of interest in many diseases. Although dual GSK3α/β inhibitors have entered clinical trials, none has successfully translated to clinical application. Mechanism-based toxicities, driven in part by the inhibition of both GSK3 paralogs and subsequent β-catenin stabilization, are a concern in the translation of this target class because mutations and overexpression of β-catenin are associated with many cancers. Knockdown of GSK3α or GSK3β individually does not increase β-catenin and offers a conceptual resolution to targeting GSK3: paralog-selective inhibition. However, inadequate chemical tools exist. The design of selective adenosine triphosphate (ATP)-competitive inhibitors poses a drug discovery challenge due to the high homology (95% identity and 100% similarity) in this binding domain. Taking advantage of an Asp133→Glu196 "switch" in their kinase hinge, we present a rational design strategy toward the discovery of paralog-selective GSK3 inhibitors. These GSK3α- and GSK3β-selective inhibitors provide insights into GSK3 targeting in acute myeloid leukemia (AML), where GSK3α was identified as a therapeutic target using genetic approaches. The GSK3α-selective compound BRD0705 inhibits kinase function and does not stabilize β-catenin, mitigating potential neoplastic concerns. BRD0705 induces myeloid differentiation and impairs colony formation in AML cells, with no apparent effect on normal hematopoietic cells. Moreover, BRD0705 impairs leukemia initiation and prolongs survival in AML mouse models. These studies demonstrate feasibility of paralog-selective GSK3α inhibition, offering a promising therapeutic approach in AML.

• Authors: Florence F Wagner, Lina Benajiba, Arthur J Campbell, Michel Weïwer, Joshua R Sacher, Jennifer P Gale, Linda Ross, Alexandre Puissant, Gabriela Alexe, Amy Conway, Morgan Back, Yana Pikman, Ilene Galinsky, Daniel J DeAngelo, Richard M Stone, Taner Kaya, Xi Shi, Matthew B Robers, Thomas Machleidt, Jennifer Wilkinson, Olivier Hermine, Andrew Kung, Adam J Stein, Damodharan Lakshminarasimhan, Michael T Hemann, Edward Scolnick, Yan-Ling Zhang, Jen Q Pan, Kimberly Stegmaier, Edward B Holson
• Journal: Science translational medicine (Sci Transl Med) Vol. 10 Issue 431 (03 07 2018) ISSN: 1946-6242 [Electronic] United States
• PMID: 29515000 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Chemical References

• Dipeptides
• Enzyme Inhibitors
• Protein Isoforms
• beta Catenin
• aspartylglutamate
• Glycogen Synthase Kinase 3

Topics

• Dipeptides (chemistry, metabolism)
• Enzyme Inhibitors (therapeutic use)
• Glycogen Synthase Kinase 3 (antagonists & inhibitors, chemistry, metabolism)
• Humans
• Leukemia, Myeloid, Acute (drug therapy)
• Mutagenesis, Site-Directed
• Protein Isoforms (antagonists & inhibitors, chemistry, metabolism)
• U937 Cells
• beta Catenin (genetics, metabolism)