ABSTRACT
The nuclear receptor-binding SET domain (NSD) family of histone methyltransferases is associated with various malignancies, including aggressive acute leukemia with NUP98-NSD1 translocation. While NSD proteins represent attractive drug targets, their catalytic SET domains exist in autoinhibited conformation, presenting notable challenges for inhibitor development. Here, we employed a fragment-based screening strategy followed by chemical optimization, which resulted in the development of the first-in-class irreversible small-molecule inhibitors of the nuclear receptor-binding SET domain protein 1 (NSD1) SET domain. The crystal structure of NSD1 in complex with covalently bound ligand reveals a conformational change in the autoinhibitory loop of the SET domain and formation of a channel-like pocket suitable for targeting with small molecules. Our covalent lead-compound BT5-demonstrates on-target activity in NUP98-NSD1 leukemia cells, including inhibition of histone H3 lysine 36 dimethylation and downregulation of target genes, and impaired colony formation in an NUP98-NSD1 patient sample. This study will facilitate the development of the next generation of potent and selective inhibitors of the NSD histone methyltransferases.
Subject(s)
Antineoplastic Agents/pharmacology , Enzyme Inhibitors/pharmacology , Gene Expression Regulation, Leukemic , Histone-Lysine N-Methyltransferase/antagonists & inhibitors , Leukocytes/drug effects , Nuclear Pore Complex Proteins/genetics , Oncogene Proteins, Fusion/antagonists & inhibitors , Antineoplastic Agents/chemical synthesis , Binding Sites , Enzyme Inhibitors/chemical synthesis , Histone-Lysine N-Methyltransferase/genetics , Histone-Lysine N-Methyltransferase/metabolism , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Humans , Kinetics , Leukemia/drug therapy , Leukemia/enzymology , Leukemia/genetics , Leukemia/pathology , Leukocytes/enzymology , Leukocytes/pathology , Models, Molecular , Myeloid Ecotropic Viral Integration Site 1 Protein/genetics , Myeloid Ecotropic Viral Integration Site 1 Protein/metabolism , Nuclear Pore Complex Proteins/metabolism , Oncogene Proteins, Fusion/genetics , Oncogene Proteins, Fusion/metabolism , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , Signal Transduction , Substrate Specificity , Tumor Cells, CulturedABSTRACT
The concept of the remote activation of reactivity was first applied in asymmetric organocatalysis. An isatin 3-phenylimine derivative acts as a donor in the thiourea catalyzed asymmetric addition to unsaturated 1,4-ketoesters, affording aza-Michael adducts in high enantiomeric purity and yield.
Subject(s)
Isatin/chemistry , Catalysis , Esters , Imines/chemistry , Molecular Structure , Stereoisomerism , Thiourea/chemistryABSTRACT
The organocatalytic Michael addition of malonates to symmetric unsaturated 1,4-diketones catalyzed by thiourea and squaramide derivatives with Cinchona alkaloids afforded the formation of a new C-C bond in high yields (up to 98%) and enantiomeric purities (up to 93%). The absolute configuration of the product was suggested from comparison of the experimental and calculated VCD spectra of the reaction product 3a.
