ABSTRACT
The frequency of poor outcomes in relapsed leukemia patients underscores the need for novel therapeutic approaches. The Food and Drug Administration-approved immunosuppressant FTY720 limits leukemia progression by activating protein phosphatase 2A and restricting nutrient access. Unfortunately, FTY720 cannot be re-purposed for use in cancer patients due to on-target toxicity associated with S1P receptor activation at the elevated, anti-neoplastic dose. Here we show that the constrained azacyclic FTY720 analog SH-RF-177 lacks S1P receptor activity but maintains anti-leukemic activity in vitro and in vivo. SH-RF-177 was not only more potent than FTY720, but killed via a distinct mechanism. Phosphorylation is dispensable for FTY720's anti-leukemic actions. However, chemical biology and genetic approaches demonstrated that the sphingosine kinase 2 (SPHK2)-mediated phosphorylation of SH-RF-177 led to engagement of a pro-apoptotic target and increased potency. The cytotoxicity of membrane-permeant FTY720 phosphonate esters suggests that the enhanced potency of SH-RF-177 stems from its more efficient phosphorylation. The tight inverse correlation between SH-RF-177 IC50 and SPHK2 mRNA expression suggests a useful biomarker for SH-RF-177 sensitivity. In summary, these studies indicate that FTY720 analogs that are efficiently phosphorylated but fail to activate S1P receptors may be superior anti-leukemic agents compared to compounds that avoid cardiotoxicity by eliminating phosphorylation.
Subject(s)
Antineoplastic Agents/pharmacology , Fingolimod Hydrochloride/pharmacology , Receptors, Lysosphingolipid/metabolism , Animals , Apoptosis/drug effects , Cell Line, Tumor , Disease Models, Animal , Drug Resistance, Neoplasm/genetics , Female , Humans , Leukemia/drug therapy , Leukemia/genetics , Leukemia/metabolism , Leukemia/pathology , Mice , Phosphorylation , Phosphotransferases (Alcohol Group Acceptor)/genetics , Receptors, Lysosphingolipid/agonists , Xenograft Model Antitumor AssaysABSTRACT
Accelerating the drug discovery process requires predictive computational protocols capable of reducing or simplifying the synthetic and/or combinatorial challenge. Docking-based virtual screening methods have been developed and successfully applied to a number of pharmaceutical targets. In this review, we first present the current status of docking and scoring methods, with exhaustive lists of these. We next discuss reported comparative studies, outlining criteria for their interpretation. In the final section, we describe some of the remaining developments that would potentially lead to a universally applicable docking/scoring method.
Subject(s)
Computer Simulation , Drug Evaluation, Preclinical/methods , Algorithms , Animals , Artificial Intelligence , Humans , Metals/chemistry , Models, Molecular , Molecular Conformation , Nucleic Acids/chemistry , Nucleic Acids/drug effects , Proteins/chemistry , Proteins/drug effects , Reproducibility of Results , Stochastic ProcessesABSTRACT
A series of N-arylsulfonyl S-alkyl homocysteine hydroxamic acids were synthesized with variations in three subsites corresponding to P(1), P(1)', and P(2)'. Enzyme assays with a variety of MMPs revealed activity at the low nanomolar level.
Subject(s)
Homocysteine/analogs & derivatives , Homocysteine/chemical synthesis , Hydroxamic Acids/chemical synthesis , Metalloendopeptidases/antagonists & inhibitors , Protease Inhibitors/chemical synthesis , Collagenases/chemistry , Homocysteine/chemistry , Hydroxamic Acids/chemistry , Matrix Metalloproteinase 1/chemistry , Matrix Metalloproteinase 13 , Matrix Metalloproteinase 2/chemistry , Matrix Metalloproteinase 3/chemistry , Matrix Metalloproteinase 9/chemistry , Matrix Metalloproteinase Inhibitors , Metalloendopeptidases/chemistry , Models, Molecular , Protease Inhibitors/chemistry , Protein Binding , Structure-Activity RelationshipABSTRACT
Conformationally constrained MMP inhibitors based on a D-proline scaffold were designed using AutoDock as a modeling program. Thus a family of D-proline hydroxamic acids, having differentiated functionality at the site of binding to the S(1) pocket, was synthesized. Biological evaluation showed low nanomolar activity and modest selectivity toward different MMP subclasses, delineating the importance of binding to the S(1) pocket for both activity and selectivity.
Subject(s)
Hydroxamic Acids/chemical synthesis , Metalloendopeptidases/antagonists & inhibitors , Proline/analogs & derivatives , Proline/chemical synthesis , Protease Inhibitors/chemical synthesis , Collagenases/chemistry , Hydroxamic Acids/chemistry , Matrix Metalloproteinase 1/chemistry , Matrix Metalloproteinase 13 , Matrix Metalloproteinase 2/chemistry , Matrix Metalloproteinase 3/chemistry , Matrix Metalloproteinase 9/chemistry , Matrix Metalloproteinase Inhibitors , Metalloendopeptidases/chemistry , Models, Molecular , Proline/chemistry , Protease Inhibitors/chemistry , Protein Binding , Protein Structure, Tertiary , Structure-Activity RelationshipABSTRACT
A focused combinatorial library of 126 mimetics of the RGD sequence based on sugar scaffolds have been rationally constructed using molecular modeling, with a particular emphasis on the stereodiversity of the library. A liquid phase, mix and divide synthesis was used, active compounds being identified by using orthogonal libraries and recursive deconvolution strategies.
Subject(s)
Combinatorial Chemistry Techniques/methods , Receptors, Vitronectin/antagonists & inhibitors , Animals , Binding, Competitive , Carbohydrates/chemistry , Cell Adhesion/drug effects , Drug Design , Fibronectins/metabolism , Mice , Models, Molecular , Molecular Mimicry , Oligopeptides/chemical synthesis , Oligopeptides/chemistry , Peptides/chemistry , Receptors, Vitronectin/metabolism , Sarcoma/pathology , Stereoisomerism , Tumor Cells, Cultured/drug effects , Vitronectin/metabolismABSTRACT
As part of a program aimed at the design and synthesis of constrained MMP inhibitors, a survey of the reported X-ray and NMR structures of MMP/inhibitor complexes was performed, revealing mutations of key amino acids at different subsites between MMPs. A comparative study of fully automated docking programs AutoDock and DOCK in closely approximating the X-ray crystal structures of ten selected MMP inhibitors was performed. AutoDock proved to be highly reliable, efficient and predictive for a set of inhibitors with less than six atom types.
Subject(s)
Drug Design , Matrix Metalloproteinase Inhibitors , Protease Inhibitors/chemistry , Protease Inhibitors/pharmacology , Binding Sites/genetics , Computer Simulation , Crystallography, X-Ray , In Vitro Techniques , Macromolecular Substances , Magnetic Resonance Spectroscopy , Matrix Metalloproteinases/chemistry , Matrix Metalloproteinases/genetics , Matrix Metalloproteinases/metabolism , Models, Molecular , Mutagenesis, Site-Directed , Protease Inhibitors/metabolism , Software , ThermodynamicsABSTRACT
In this paper, we investigate the common structural and electrostatic parameters of a series of specific inhibitors of the alpha IIb beta 3 integrin. Molecular dynamics simulations with an explicit aqueous environment led to an original theoretical pattern. Our results may suggest that the studied non-peptide alpha IIb beta 3 antagonists developed upon the Arg-Gly-Asp ubiquitous recognition sequence, in fact, should mimic the C-terminus part of the fibrinogen gamma chain. This assumption could, therefore, explain their specificity with respect to other Arg-Gly-Asp-dependent integrins.
