ABSTRACT
Triple-negative breast cancer (TNBC) is an aggressive breast-cancer subtype associated with poor prognosis and high relapse rates. Monopolar spindle 1 kinase (MPS1) is an apical dual-specificity protein kinase that is over-expressed in TNBC. We herein report a highly selective MPS1 inhibitor based on a 7H-pyrrolo[2,3-d]pyrimidine-5-carbonitrile scaffold. Our lead optimization was guided by key X-ray crystal structure analysis. In vivo evaluation of candidate (9) is shown to effectively mitigate human TNBC cell proliferation.
Subject(s)
Cell Cycle Proteins/antagonists & inhibitors , Drug Design , Protein Kinase Inhibitors/chemistry , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein-Tyrosine Kinases/antagonists & inhibitors , Pyrimidines/chemistry , Pyrroles/chemistry , Administration, Oral , Animals , Binding Sites , Breast Neoplasms/drug therapy , Breast Neoplasms/pathology , Cell Cycle Proteins/metabolism , Cell Line, Tumor , Crystallography, X-Ray , Female , Half-Life , Humans , Mice , Mice, Inbred ICR , Molecular Docking Simulation , Protein Kinase Inhibitors/metabolism , Protein Kinase Inhibitors/therapeutic use , Protein Serine-Threonine Kinases/metabolism , Protein-Tyrosine Kinases/metabolism , Pyrimidines/metabolism , Pyrimidines/therapeutic use , Pyrroles/metabolism , Pyrroles/therapeutic use , Structure-Activity Relationship , Transplantation, HeterologousABSTRACT
GNF-7, a multitargeted kinase inhibitor, served as a dual kinase inhibitor of ACK1 and GCK, which provided a novel therapeutic strategy for overriding AML expressing NRAS mutation. This SAR study with GNF-7 derivatives, designed to target NRAS mutant-driven AML, led to identification of the extremely potent inhibitors, 10d, 10g, and 11i, which possess single-digit nanomolar inhibitory activity against both ACK1 and GCK. These substances strongly suppress proliferation of mutant NRAS expressing AML cells via apoptosis and AKT/mTOR signaling blockade. Compound 11i is superior to GNF-7 in terms of kinase inhibitory activity, cellular activity, and differential cytotoxicity. Moreover, 10k possessing a favorable mouse pharmacokinetic profile prolonged life-span of Ba/F3-NRAS-G12D injected mice and significantly delayed tumor growth of OCI-AML3 xenograft model without causing the prominent level of toxicity found with GNF-7. Taken together, this study provides insight into the design of novel ACK1 and GCK dual inhibitors for overriding NRAS mutant-driven AML.
Subject(s)
Antineoplastic Agents/pharmacology , GTP Phosphohydrolases/genetics , Leukemia, Myeloid, Acute/drug therapy , Membrane Proteins/genetics , Mutation , Protein Kinase Inhibitors/pharmacology , Animals , Antineoplastic Agents/chemistry , Apoptosis , Cell Survival , Female , Humans , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/pathology , Mice , Mice, Nude , Models, Molecular , Molecular Structure , Protein Conformation , Protein Kinase Inhibitors/chemistry , Signal Transduction , Structure-Activity Relationship , Tumor Cells, Cultured , Xenograft Model Antitumor AssaysABSTRACT
Vancomycin resistance in Enterococci and its transfer to methicillin-resistant Staphylococcus aureus are challenging problems in health care institutions worldwide. High-level vancomycin resistance is conferred by acquiring either transposable elements of the VanA or VanB type. Enterococcus faecalis VanYB in the VanB-type operon is a d,d-carboxypeptidase that recognizes the peptidyl-d-Ala4-d-Ala5 extremity of peptidoglycan and hydrolyses the terminal d-Ala on the extracellular side of the cell wall, thereby increasing the level of glycopeptide antibiotics resistance. However, at the molecular level, it remains unclear how VanYB manipulates peptidoglycan peptides for vancomycin resistance. In this study, we have determined the crystal structures of E. faecalis VanYB in the d-Ala-d-Ala-bound, d-Ala-bound, and -unbound states. The interactions between VanYB and d-Ala-d-Ala observed in the crystal provide the molecular basis for the recognition of peptidoglycan substrates by VanYB. Moreover, comparisons with the related VanX and VanXY enzymes reveal distinct structural features of E. faecalis VanYB around the active-site cleft, thus shedding light on its unique substrate specificity. Our results could serve as the foundation for unravelling the molecular mechanism of vancomycin resistance and for developing novel antibiotics against the vancomycin-resistant Enterococcus species.
Subject(s)
Enterococcus faecalis/chemistry , Oligopeptides/chemistry , Peptidoglycan/chemistry , Amino Acid Sequence , Catalytic Domain , Enterococcus faecalis/enzymology , Ligands , Models, Molecular , Molecular Structure , Peptide Hydrolases/chemistry , Peptide Hydrolases/metabolism , Protein Binding , Protein Conformation , Substrate Specificity , Zinc/chemistryABSTRACT
The TB Structural Genomics Consortium is a worldwide organization of collaborators whose mission is the comprehensive structural determination and analyses of Mycobacterium tuberculosis proteins to ultimately aid in tuberculosis diagnosis and treatment. Congruent to the overall vision, Consortium members have additionally established an integrated facilities core to streamline M. tuberculosis structural biology and developed bioinformatics resources for data mining. This review aims to share the latest Consortium developments with the TB community, including recent structures of proteins that play significant roles within M. tuberculosis. Atomic resolution details may unravel mechanistic insights and reveal unique and novel protein features, as well as important protein-protein and protein-ligand interactions, which ultimately lead to a better understanding of M. tuberculosis biology and may be exploited for rational, structure-based therapeutics design.
