ABSTRACT
The challenge for glycogen synthase kinase-3 (GSK-3) inhibitor design lies in achieving high selectivity for one isoform over the other. The therapy of certain diseases, such as acute myeloid leukemia (AML), may require α-isoform specific targeting. The scorpion shaped GSK-3 inhibitors developed by our group achieved the highest GSK-3α selectivity reported so far but suffered from insufficient aqueous solubility. This work presents the solubility-driven optimization of our isoform-selective inhibitors using a scorpion shaped lead. Among 15 novel compounds, compound 27 showed high activity against GSK-3α/ß with the highest GSK-3α selectivity reported to date. Compound 27 was profiled for bioavailability and toxicity in a zebrafish embryo phenotype assay. Selective GSK-3α targeting in AML cell lines was achieved with compound 27, resulting in a strong differentiation phenotype and colony formation impairment, confirming the potential of GSK-3α inhibition in AML therapy.
Subject(s)
Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/therapeutic use , Glycogen Synthase Kinase 3/antagonists & inhibitors , Leukemia, Myeloid, Acute/drug therapy , Animals , Cell Differentiation , Cell Line, Tumor , Glycogen Synthase Kinase 3/chemistry , Glycogen Synthase Kinase 3 beta , HL-60 Cells , Humans , Isoenzymes , Models, Molecular , Molecular Conformation , Solubility , Structure-Activity Relationship , Tumor Stem Cell Assay , ZebrafishABSTRACT
Activating mutations of FMS-like tyrosine kinaseâ 3 (FLT3) are present in â¼30 % of patients with acute myeloid leukemia (AML) and are associated with poor prognosis. Point mutations in the tyrosine kinase domain (TKD) are observed as primary mutations or are acquired as secondary mutations in FLT3 with internal tandem duplications (ITDs) after treatment with tyrosine kinase inhibitors (TKIs). Although dozens of potent inhibitors against FLT3 ITD have been reported, activating TKD point mutations, especially at residues F691 and D835, remain the leading cause for therapy resistance, highlighting the consistent need for new potent inhibitors. Herein we report the identification and characterization of novel quinoxaline-based FLT3 inhibitors. We used the pharmacophore features of diverse known inhibitors as a starting point for a new optimization algorithm for typeâ II TKIs, starting from an in silico library pharmacophore search and induced-fit docking in the known FLT3 structure. This led to the design of a set of diverse quinoxalinebisarylureas, which were profiled in an FLT3 kinase activity assay. The most promising compounds were further evaluated in a zebrafish embryo phenotype assay.
Subject(s)
Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Quinoxalines/chemistry , Quinoxalines/pharmacology , fms-Like Tyrosine Kinase 3/antagonists & inhibitors , Animals , Drug Design , Humans , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/enzymology , Molecular Docking Simulation , Protein Kinase Inhibitors/chemical synthesis , Quinoxalines/chemical synthesis , Zebrafish , fms-Like Tyrosine Kinase 3/chemistry , fms-Like Tyrosine Kinase 3/metabolismABSTRACT
The most prevalent leucine-rich repeat kinase 2 (LRRK2) mutation G2019S is associated with Parkinson's disease (PD). It enhances kinase activity and has been identified in both familial and sporadic cases. Kinase activity was reported to be required for LRRK2 mutants to exert their toxic effects. Hence LRRK2 kinase inhibition may be a promising therapeutic target for PD. Here we report on the discovery and characterization of indolinone based LRRK2 inhibitors. Indolinone 15b, the most potent and selective inhibitor of the present series, is characterized by an IC50 of 15nM against wild-type LRRK2 and 10nM against the LRRK2 G2019S mutant, respectively. Compound 15b was further evaluated in a kinase panel including 46 human protein kinases and in a zebrafish embryo phenotype assay, which enabled toxicity determination in whole organisms.
Subject(s)
Indoles/pharmacology , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Zebrafish Proteins/antagonists & inhibitors , Animals , Dose-Response Relationship, Drug , Humans , Hydrogen Bonding , Indoles/chemical synthesis , Indoles/chemistry , Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 , Molecular Structure , Phenotype , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/chemistry , Protein Serine-Threonine Kinases/metabolism , Structure-Activity Relationship , Zebrafish/embryology , Zebrafish/metabolism , Zebrafish Proteins/metabolismABSTRACT
Modulation of γ-secretase activity is a promising therapeutic strategy for the treatment of Alzheimer's disease. Herein we report on the synthesis of carprofen- and tocopherol-derived small-molecule modulators carrying terpene moieties as lipophilic membrane anchors. Additionally, these modulators are equipped with an acidic moiety, which contributes to the desired modulatory effect on the γ-secretase with decreased formation of Aß42 and increased Aß38 production.
Subject(s)
Amyloid Precursor Protein Secretases/metabolism , Cell Membrane/enzymology , Small Molecule Libraries/pharmacology , Terpenes/pharmacology , Amyloid Precursor Protein Secretases/chemistry , Animals , CHO Cells , Cell Membrane/metabolism , Cricetulus , Dose-Response Relationship, Drug , Hydrophobic and Hydrophilic Interactions , Molecular Structure , Small Molecule Libraries/chemical synthesis , Small Molecule Libraries/chemistry , Structure-Activity Relationship , Terpenes/chemical synthesis , Terpenes/chemistryABSTRACT
The inhibition of FLT-3 activity is an interesting target for the treatment of acute myeloid leukemia (AML). The serendipitous identification of FLT-3 inhibitors from a CK1/γ-secretase programme provided compounds with dual inhibitory activity. We analyzed the structure-activity relationship of these inhibitors and derivatized them to arrive at compounds with reduced impact on γ-secretase activity and enhanced FLT-3 inhibition.
Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , fms-Like Tyrosine Kinase 3/antagonists & inhibitors , Amyloid Precursor Protein Secretases/metabolism , Animals , Dose-Response Relationship, Drug , Embryo, Nonmammalian/drug effects , Enzyme Inhibitors/chemical synthesis , Humans , Molecular Structure , Phenotype , Recombinant Proteins/antagonists & inhibitors , Recombinant Proteins/metabolism , Structure-Activity Relationship , Substrate Specificity , Zebrafish/embryology , fms-Like Tyrosine Kinase 3/metabolismABSTRACT
Parkinson's disease (PD) is the second most common neurodegenerative disorder. Several single gene mutations have been linked to this disease. Mutations in the gene encoding leucine-rich repeat kinase 2 (LRRK2) indicate LRRK2 as promising therapeutic target for the treatment of PD. LRRK2 mutations were observed in sporadic as well as familial PD patients and have been investigated intensively. LRRK2 is a large and complex protein, with multiple enzymatic and protein-interaction domains, each of which is effected by mutations. The most common mutation in PD patients is G2019S. Several LRRK2 inhibitors have been reported already, although the crystal structure of LRRK2 has not yet been determined. This review provides a summary of known LRRK2 inhibitors and will discuss recent in vitro and in vivo results of these inhibitors.
