ABSTRACT
We previously demonstrated that natural product-inspired 3,4-dihydropyrrolo[1,2-a]pyrazin-1(2H)-ones derivatives delivered potent and selective PIM kinases inhibitors however with non-optimal ADME/PK properties and modest oral bioavailability. Herein, we describe a structure-based scaffold decoration and a stereoselective approach to this chemical class. The synthesis, structure-activity relationship studies, chiral analysis, and pharmacokinetic data of compounds from this inhibitor class are presented herein. Compound 20c demonstrated excellent potency on PIM1 and PIM2 with exquisite kinases selectivity and PK properties that efficiently and dose-dependently promoted c-Myc degradation and appear to be promising lead compounds for further development.
Subject(s)
Alkaloids , Antineoplastic Agents , Alkaloids/pharmacology , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-pim-1/chemistry , Proto-Oncogene Proteins c-pim-1/metabolism , Stereoisomerism , Structure-Activity RelationshipABSTRACT
In this article we describe the identification of unprecedented ATP-competitive ChoKα inhibitors starting from initial hit NMS-P830 that binds to ChoKα in an ATP concentration-dependent manner. This result is confirmed by the co-crystal structure of NMS-P830 in complex with Δ75-ChoKα. NMS-P830 is able to inhibit ChoKα in cells resulting in the reduction of intracellular phosphocholine formation. A structure-based medicinal chemistry program resulted in the identification of selective compounds that have good biochemical activity, solubility and metabolic stability and are suitable for further optimization. The ChoKα inhibitors disclosed in this article demonstrate for the first time the possibility to inhibit ChoKα with ATP-competitive compounds.
Subject(s)
Adenosine Triphosphate/antagonists & inhibitors , Choline Kinase/antagonists & inhibitors , Cyclohexanes/pharmacology , Protein Kinase Inhibitors/pharmacology , Adenosine Triphosphate/metabolism , Choline Kinase/metabolism , Cyclohexanes/chemical synthesis , Cyclohexanes/chemistry , Dose-Response Relationship, Drug , Humans , Molecular Structure , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/chemistry , Structure-Activity RelationshipABSTRACT
NGR-hTNF is a therapeutic agent for a solid tumor that specifically targets angiogenic tumor blood vessels, through the NGR motif. Its activity has been assessed in several clinical studies encompassing tumors of different histological types. The drug's activity is based on an improved permeabilization of newly formed tumor vasculature, which favors intratumor penetration of chemotherapeutic agents and leukocyte trafficking. This work investigated the binding and the signaling properties of the NGR-hTNF, to elucidate its mechanism of action. The crystal structure of NGR-hTNF and modeling of its interaction with TNFR suggested that the NGR region is available for binding to a specific receptor. Using 2D TR-NOESY experiments, this study confirmed that the NGR-peptides binds to a specific CD13 isoform, whose expression is restricted to tumor vasculature cells, and to some tumor cell lines. The interaction between hTNF or NGR-hTNF with immobilized TNFRs showed similar kinetic parameters, whereas the competition experiments performed on the cells expressing both TNFR and CD13 showed that NGR-hTNF had a higher binding affinity than hTNF. The analysis of the NGR-hTNF-triggered signal transduction events showed a specific impairment in the activation of pro-survival pathways (Ras, Erk and Akt), compared to hTNF. Since a signaling pattern identical to NGR-hTNF was obtained with hTNF and NGR-sequence given as distinct molecules, the inhibition observed on the survival pathways was presumably due to a direct effect of the NGR-CD13 engagement on the TNFR signaling pathway. The reduced activation of the pro survival pathways induced by NGR-hTNF correlated with the increased caspases activation and reduced cell survival. This study demonstrates that the binding of the NGR-motif to CD13 determines not only the homing of NGR-hTNF to tumor vessels, but also the increase in its antiangiogenic activity.
Subject(s)
Angiogenesis Inhibitors/pharmacology , Neoplasms/blood supply , Oligopeptides/pharmacology , Recombinant Fusion Proteins/pharmacology , Tumor Necrosis Factor-alpha/pharmacology , Angiogenesis Inhibitors/chemistry , Cell Line, Tumor , Crystallography, X-Ray , Human Umbilical Vein Endothelial Cells , Humans , Models, Molecular , Oligopeptides/chemistry , Recombinant Fusion Proteins/chemistry , Signal Transduction/drug effects , Tumor Necrosis Factor-alpha/chemistryABSTRACT
Poly(ADP-ribose) polymerase-1 (PARP-1) is an enzyme involved in signaling and repair of DNA single strand breaks. PARP-1 employs NAD+ to modify substrate proteins via the attachment of poly(ADP-ribose) chains. PARP-1 is a well established target in oncology, as testified by the number of marketed drugs (e.g., Lynparza, Rubraca, Zejula, and Talzenna) used for the treatment of ovarian, breast, and prostate tumors. Efforts in investigating an uncharted region of the previously identified isoindolinone carboxamide series delivered (S)-13 (NMS-P515), a potent inhibitor of PARP-1 both in biochemical (K d: 0.016 µM) and cellular (IC50: 0.027 µM) assays. Cocrystal structure allowed explaining NMS-P515 stereospecific inhibition of the target. After having ruled out potential loss of enantiopurity in vitro and in vivo, NMS-P515 was synthesized in an asymmetric fashion. NMS-P515 ADME profile and its antitumor activity in a mouse xenograft cancer model render the compound eligible for further optimization.
ABSTRACT
Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase responsible for the development of different tumor types. Despite the remarkable clinical activity of crizotinib (Xalkori), the first ALK inhibitor approved in 2011, the emergence of resistance mutations and of brain metastases frequently causes relapse in patients. Within our ALK drug discovery program, we identified compound 1, a novel 3-aminoindazole active on ALK in biochemical and in cellular assays. Its optimization led to compound 2 (entrectinib), a potent orally available ALK inhibitor active on ALK-dependent cell lines, efficiently penetrant the blood-brain barrier (BBB) in different animal species and highly efficacious in in vivo xenograft models. Moreover, entrectinib resulted to be strictly potent on the closely related tyrosine kinases ROS1 and TRKs recently found constitutively activated in several tumor types. Entrectinib is currently undergoing phase I/II clinical trial for the treatment of patients affected by ALK-, ROS1-, and TRK-positive tumors.
Subject(s)
Antineoplastic Agents/pharmacology , Benzamides/pharmacology , Drug Discovery , Indazoles/pharmacology , Lung Neoplasms/drug therapy , Protein Kinase Inhibitors/pharmacology , Protein-Tyrosine Kinases/antagonists & inhibitors , Receptor Protein-Tyrosine Kinases/antagonists & inhibitors , Administration, Oral , Anaplastic Lymphoma Kinase , Animals , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/chemistry , Benzamides/administration & dosage , Benzamides/chemistry , Blood-Brain Barrier/drug effects , Blotting, Western , Cell Membrane Permeability/drug effects , Cell Proliferation/drug effects , Crystallization , Crystallography, X-Ray , Dogs , Humans , Indazoles/administration & dosage , Indazoles/chemistry , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Mice , Mice, Nude , Mice, SCID , Microsomes, Liver/drug effects , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/chemistry , Proto-Oncogene Proteins/antagonists & inhibitors , Rats , Rats, Wistar , Receptor, trkA/antagonists & inhibitors , Receptor, trkB/antagonists & inhibitors , Receptor, trkC/antagonists & inhibitors , Tumor Cells, Cultured , Xenograft Model Antitumor AssaysABSTRACT
Activated ALK and ROS1 tyrosine kinases, resulting from chromosomal rearrangements, occur in a subset of non-small cell lung cancers (NSCLC) as well as other tumor types and their oncogenic relevance as actionable targets has been demonstrated by the efficacy of selective kinase inhibitors such as crizotinib, ceritinib, and alectinib. More recently, low-frequency rearrangements of TRK kinases have been described in NSCLC, colorectal carcinoma, glioblastoma, and Spitzoid melanoma. Entrectinib, whose discovery and preclinical characterization are reported herein, is a novel, potent inhibitor of ALK, ROS1, and, importantly, of TRK family kinases, which shows promise for therapy of tumors bearing oncogenic forms of these proteins. Proliferation profiling against over 200 human tumor cell lines revealed that entrectinib is exquisitely potent in vitro against lines that are dependent on the drug's pharmacologic targets. Oral administration of entrectinib to tumor-bearing mice induced regression in relevant human xenograft tumors, including the TRKA-dependent colorectal carcinoma KM12, ROS1-driven tumors, and several ALK-dependent models of different tissue origins, including a model of brain-localized lung cancer metastasis. Entrectinib is currently showing great promise in phase I/II clinical trials, including the first documented objective responses to a TRK inhibitor in colorectal carcinoma and in NSCLC. The drug is, thus, potentially suited to the therapy of several molecularly defined cancer settings, especially that of TRK-dependent tumors, for which no approved drugs are currently available. Mol Cancer Ther; 15(4); 628-39. ©2016 AACR.
Subject(s)
Antineoplastic Agents/pharmacology , Benzamides/pharmacology , Indazoles/pharmacology , Protein Kinase Inhibitors/pharmacology , Anaplastic Lymphoma Kinase , Animals , Benzamides/chemistry , Cell Line, Tumor , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/pathology , Disease Models, Animal , Enzyme Activation/drug effects , Humans , Indazoles/chemistry , Magnetic Resonance Imaging , Male , Mice , Mice, Transgenic , Mortality , Protein Kinase Inhibitors/chemistry , Protein-Tyrosine Kinases/antagonists & inhibitors , Proto-Oncogene Proteins/antagonists & inhibitors , Receptor Protein-Tyrosine Kinases/antagonists & inhibitors , Translocation, Genetic , Treatment Outcome , Xenograft Model Antitumor AssaysABSTRACT
Compound 1, a hit from the screening of our chemical collection displaying activity against JAK2, was deconstructed for SAR analysis into three regions, which were explored. A series of compounds was synthesized leading to the identification of the potent and orally bioavailable JAK2 inhibitor 16 (NMS-P830), which showed an encouraging tumour growth inhibition in SET-2 xenograft tumour model, with evidence for JAK2 pathway suppression demonstrated by in vivo pharmacodynamic effects.
Subject(s)
Amides/chemical synthesis , Antineoplastic Agents/chemical synthesis , Janus Kinase 2/antagonists & inhibitors , Leukemia, Megakaryoblastic, Acute/drug therapy , Protein Kinase Inhibitors/chemical synthesis , Pyrroles/chemical synthesis , Amides/pharmacology , Animals , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Female , Gene Expression , High-Throughput Screening Assays , Humans , Janus Kinase 2/chemistry , Janus Kinase 2/genetics , Janus Kinase 2/metabolism , Leukemia, Megakaryoblastic, Acute/enzymology , Leukemia, Megakaryoblastic, Acute/genetics , Leukemia, Megakaryoblastic, Acute/pathology , Megakaryocyte Progenitor Cells/drug effects , Megakaryocyte Progenitor Cells/enzymology , Megakaryocyte Progenitor Cells/pathology , Mice , Mice, Nude , Molecular Docking Simulation , Molecular Dynamics Simulation , Protein Kinase Inhibitors/pharmacology , Pyrroles/pharmacology , Structure-Activity Relationship , Xenograft Model Antitumor AssaysABSTRACT
Valosine-containing protein (VCP), also known as p97 or cdc48 in yeast, is a highly abundant protein belonging to the AAA ATPase family involved in a number of essential cellular functions, including ubiquitin-proteasome mediated protein degradation, Golgi reassembly, transcription activation, and cell cycle control. Altered expression of VCP has been detected in many cancer types sometimes associated with poor prognosis. Furthermore, VCP mutations are causative of some neurodegenerative disorders. In this paper we report the discovery, synthesis, and structure-activity relationships of substituted 2-aminopyrimidines, representing a new class of reversible VCP inhibitors. This class of compounds, identified in a HTS campaign against recombinant VCP, has been progressively expanded and manipulated to increase biochemical potency and gain cellular activity.
Subject(s)
Adenosine Triphosphatases/antagonists & inhibitors , Cell Cycle Proteins/antagonists & inhibitors , Cell Proliferation/drug effects , Drug Discovery , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Pyrimidines/chemistry , Pyrimidines/pharmacology , Adenosine Triphosphatases/metabolism , Cell Cycle Proteins/metabolism , HCT116 Cells , Humans , Models, Molecular , Molecular Structure , Structure-Activity Relationship , Valosin Containing ProteinABSTRACT
We report herein the discovery, structure guided design, synthesis and biological evaluation of a novel class of JAK2 inhibitors. Optimization of the series led to the identification of the potent and orally bioavailable JAK2 inhibitor 28 (NMS-P953). Compound 28 displayed significant tumour growth inhibition in SET-2 xenograft tumour model, with a mechanism of action confirmed in vivo by typical modulation of known biomarkers, and with a favourable pharmacokinetic and safety profile.
Subject(s)
Antineoplastic Agents/pharmacology , Janus Kinase 2/antagonists & inhibitors , Neoplasms, Experimental/drug therapy , Protein Kinase Inhibitors/pharmacology , Pyrimidines/pharmacology , Pyrroles/pharmacology , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Proliferation/drug effects , Crystallography, X-Ray , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , Janus Kinase 2/metabolism , Mice , Mice, SCID , Models, Molecular , Molecular Structure , Neoplasms, Experimental/pathology , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/chemistry , Pyrimidines/chemical synthesis , Pyrimidines/chemistry , Pyrroles/chemical synthesis , Pyrroles/chemistry , Structure-Activity Relationship , Substrate SpecificityABSTRACT
PARP inhibitors are an exciting new class of antineoplastic drugs that have been proven to be efficacious as single agents in cancer settings with inherent DNA repair defects, as well as in combination with DNA-damaging chemotherapeutics. Currently, they are designed to target the catalytic domain of PARP-1, the most studied member of the family, with a key role in the DNA-damage repair process. Because PARP inhibitors are substrate (NAD(+)) competitors, there is a need for a deeper understanding of their cross-reactivity. This is particularly relevant for PARP-2, the PARP-1 closest homologue, for which an embryonic lethal phenotype has been observed in double knockout mice. In this study, we describe the development and validation of binding assays based on fluorescence polarization (FP) and surface plasmon resonance (SPR) techniques. PARP-1, PARP-2, PARP-3, and TNKS-1 FP displacement assays are set up by employing ad hoc synthesized probes. These assays are suitable for high-throughput screening (HTS) and selectivity profiling, thus allowing the identification of NAD(+)binding site selective inhibitors. The PARP-1 and PARP-2 complementary SPR binding assays confirm displacement data and the in-depth inhibitor characterization. Moreover, these formats have the potential to be broadly applicable to other members of the PARP family.
Subject(s)
Fluorescence Polarization/methods , High-Throughput Screening Assays/methods , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology , Surface Plasmon Resonance/methods , Cell Cycle Proteins/antagonists & inhibitors , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Humans , Poly (ADP-Ribose) Polymerase-1/antagonists & inhibitors , Poly (ADP-Ribose) Polymerase-1/genetics , Poly (ADP-Ribose) Polymerase-1/metabolism , Poly(ADP-ribose) Polymerase Inhibitors/metabolism , Poly(ADP-ribose) Polymerases/genetics , Poly(ADP-ribose) Polymerases/metabolism , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Reproducibility of Results , Tankyrases/genetics , Tankyrases/metabolismABSTRACT
The NTRK1 gene encodes Tropomyosin-related kinase A (TRKA), the high-affinity Nerve Growth Factor Receptor. NTRK1 was originally isolated from a colorectal carcinoma (CRC) sample as component of a somatic rearrangement (TPM3-NTRK1) resulting in expression of the oncogenic chimeric protein TPM3-TRKA, but there has been no subsequent report regarding the relevance of this oncogene in CRC. The KM12 human CRC cell line expresses the chimeric TPM3-TRKA protein and is hypersensitive to TRKA kinase inhibition. We report the detailed characterization of the TPM3-NTRK1 genomic rearrangement in KM12 cells and through a cellular screening approach, the identification of NMS-P626, a novel highly potent and selective TRKA inhibitor. NMS-P626 suppressed TPM3-TRKA phosphorylation and downstream signaling in KM12 cells and showed remarkable antitumor activity in mice bearing KM12 tumors. Finally, using quantitative reverse transcriptase PCR and immunohistochemistry (IHC) we identified the TPM3-NTRK1 rearrangement in a CRC clinical sample, therefore suggesting that this chromosomal translocation is indeed a low frequency recurring event in CRC and that such patients might benefit from therapy with TRKA kinase inhibitors.
Subject(s)
Protein Kinase Inhibitors/pharmacology , Receptor, trkA/antagonists & inhibitors , Receptor, trkA/metabolism , Tropomyosin/metabolism , Animals , Blotting, Western , Cell Line , Cell Line, Tumor , Cell Proliferation/drug effects , Humans , Immunoprecipitation , In Vitro Techniques , Mice , Protein Binding/drug effectsABSTRACT
The activity of the cyclin-dependent kinaseâ 9 (CDK9) is critical for HIV-1 Tat-mediated transcription and represents a promising target for antiviral therapy. Here we present computational studies that, along with preliminary synthetic efforts, allowed us to identify and characterize a new class of nontoxic anti-CDK9 chemotypes based on the 2-phenylquinazolinone scaffold. Inhibition of CDK9 translated into the ability to interfere selectively with Tat-mediated transactivation of the viral promoter and in the inhibition of HIV-1 reactivation from latently infected cells, with the most potent derivative 37 (2-(4-aminophenyl)-7-chloroquinazolin-4(3H)-one) showing an IC50 value of 4.0â µM. Because the herein reported 2-phenylquinazolinones are merely fragments, they are largely optimizable, paving the way to derivatives with improved potency.
Subject(s)
Computer-Aided Design , Cyclin-Dependent Kinase 9/antagonists & inhibitors , HIV-1/metabolism , Protein Kinase Inhibitors/chemical synthesis , Quinazolinones/chemistry , tat Gene Products, Human Immunodeficiency Virus/metabolism , Binding Sites , Cell Line , Cell Survival/drug effects , Cyclin-Dependent Kinase 9/metabolism , HeLa Cells , Humans , Molecular Docking Simulation , Protein Binding , Protein Kinase Inhibitors/metabolism , Protein Kinase Inhibitors/toxicity , Protein Structure, Tertiary , Quinazolinones/metabolism , Quinazolinones/toxicity , Structure-Activity Relationship , Transcription, Genetic/drug effects , tat Gene Products, Human Immunodeficiency Virus/geneticsABSTRACT
A novel series of PIM inhibitors was derived from a combined effort in natural product-inspired library generation and screening. The novel pyrrolo[1,2-a]pyrazinones initial hits are inhibitors of PIM isoforms with IC50 values in the low micromolar range. The application of a rational optimization strategy, guided by the determination of the crystal structure of the complex in the kinase domain of PIM1 with compound 1, led to the discovery of compound 15a, which is a potent PIM kinases inhibitor exhibiting excellent selectivity against a large panel of kinases, representative of each family. The synthesis, structure-activity relationship studies, and pharmacokinetic data of compounds from this inhibitor class are presented herein. Furthermore, the cellular activities including inhibition of cell growth and modulation of downstream targets are also described.
Subject(s)
Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-pim-1/antagonists & inhibitors , Pyrazines/chemistry , Pyrazines/pharmacology , Drug Discovery , Humans , Molecular Docking Simulation , Protein Kinase Inhibitors/chemical synthesis , Protein Structure, Tertiary , Proto-Oncogene Proteins c-pim-1/chemistry , Proto-Oncogene Proteins c-pim-1/metabolism , Pyrazines/chemical synthesisABSTRACT
VCP (also known as p97 or Cdc48p in yeast) is an AAA(+) ATPase regulating endoplasmic reticulum-associated degradation. After high-throughput screening, we developed compounds that inhibit VCP via different mechanisms, including covalent modification of an active site cysteine and a new allosteric mechanism. Using photoaffinity labeling, structural analysis and mutagenesis, we mapped the binding site of allosteric inhibitors to a region spanning the D1 and D2 domains of adjacent protomers encompassing elements important for nucleotide-state sensing and ATP hydrolysis. These compounds induced an increased affinity for nucleotides. Interference with nucleotide turnover in individual subunits and distortion of interprotomer communication cooperated to impair VCP enzymatic activity. Chemical expansion of this allosteric class identified NMS-873, the most potent and specific VCP inhibitor described to date, which activated the unfolded protein response, interfered with autophagy and induced cancer cell death. The consistent pattern of cancer cell killing by covalent and allosteric inhibitors provided critical validation of VCP as a cancer target.
Subject(s)
Acetanilides/pharmacology , Adenosine Triphosphatases/antagonists & inhibitors , Antineoplastic Agents/pharmacology , Benzothiazoles/pharmacology , Cell Cycle Proteins/antagonists & inhibitors , Enzyme Inhibitors/pharmacology , Neoplasms/drug therapy , Neoplasms/pathology , Acetanilides/chemistry , Adenosine Triphosphatases/metabolism , Allosteric Regulation/drug effects , Antineoplastic Agents/chemistry , Benzothiazoles/chemistry , Cell Cycle Proteins/metabolism , Cell Death/drug effects , Cell Line, Tumor , Enzyme Inhibitors/chemistry , Humans , Models, Molecular , Molecular Structure , Neoplasms/metabolism , Structure-Activity Relationship , Valosin Containing ProteinABSTRACT
Valosine containing protein (VCP), also known as p97, is a member of AAA ATPase family that is involved in several biological processes and plays a central role in the ubiquitin-mediated degradation of misfolded proteins. VCP is an ubiquitously expressed, highly abundant protein and has been found overexpressed in many tumor types, sometimes associated with poor prognosis. In this respect, VCP has recently received a great deal of attention as a potential new target for cancer therapy. In this paper, the discovery and structure-activity relationships of alkylsulfanyl-1,2,4-triazoles, a new class of potent, allosteric VCP inhibitors, are described. Medicinal chemistry manipulation of compound 1, identified via HTS, led to the discovery of potent and selective inhibitors with submicromolar activity in cells and clear mechanism of action at consistent doses. This represents a first step toward a new class of potential anticancer agents.
Subject(s)
Adenosine Triphosphatases/antagonists & inhibitors , Cell Cycle Proteins/antagonists & inhibitors , Triazoles/pharmacology , Adenosine Triphosphatases/chemistry , Allosteric Regulation , Cell Cycle Proteins/chemistry , Humans , Neoplasms/pathology , Structure-Activity Relationship , Triazoles/chemical synthesis , Triazoles/chemistry , Valosin Containing ProteinABSTRACT
The generation of novel chemotypes in support of our oncology research projects expanded in recent years from a canonical design of kinase-targeted compound libraries to a broader interpretation of purinome-targeted libraries (PTL) addressing the specificity of cancer relevant targets such as kinases and ATPases. Successful screening of structurally diverse ATP-binding targets requires compound libraries covering multiple design elements, which may include phosphate surrogate moieties in ATPase inhibitors or far reaching lipophilic residues stabilizing inactive kinase conformations. Here, we exemplify the design and preparation of drug-like combinatorial libraries and report significantly enhanced screening performance on purinomic targets. We compared overall hit rates of PTL with a simultaneously tested unbiased collection of 200,000 compounds and found consistent superiority of the targeted libraries in all cases. We also analyzed the performance of the largest targeted libraries in comparison with each other and often found striking differences in how a specific target responds to various chemotypes and to whole collections.
Subject(s)
Adenosine Triphosphate/analogs & derivatives , Combinatorial Chemistry Techniques/methods , Drug Design , Small Molecule Libraries/analysis , Small Molecule Libraries/pharmacology , Binding Sites , Databases as Topic , High-Throughput Screening Assays , Models, Molecular , Protein Kinase Inhibitors/analysis , Protein Kinase Inhibitors/pharmacology , Protein Kinases/metabolism , Pyrazoles/chemistry , Reference StandardsABSTRACT
Polo-like kinase 1 (PLK1) is a serine/threonine protein kinase considered to be the master player of cell-cycle regulation during mitosis. It is indeed involved in centrosome maturation, bipolar spindle formation, chromosome separation, and cytokinesis. PLK1 is overexpressed in a variety of human tumors and its overexpression often correlates with poor prognosis. Although five different PLKs are described in humans, depletion or inhibition of kinase activity of PLK1 is sufficient to induce cell-cycle arrest and apoptosis in cancer cell lines and in xenograft tumor models. NMS-P937 is a novel, orally available PLK1-specific inhibitor. The compound shows high potency in proliferation assays having low nanomolar activity on a large number of cell lines, both from solid and hematologic tumors. NMS-P937 potently causes a mitotic cell-cycle arrest followed by apoptosis in cancer cell lines and inhibits xenograft tumor growth with clear PLK1-related mechanism of action at well-tolerated doses in mice after oral administration. In addition, NMS-P937 shows potential for combination in clinical settings with approved cytotoxic drugs, causing tumor regression in HT29 human colon adenocarcinoma xenografts upon combination with irinotecan and prolonged survival of animals in a disseminated model of acute myelogenous leukemia in combination with cytarabine. NMS-P937, with its favorable pharmacologic parameters, good oral bioavailability in rodent and nonrodent species, and proven antitumor activity in different preclinical models using a variety of dosing regimens, potentially provides a high degree of flexibility in dosing schedules and warrants investigation in clinical settings.
Subject(s)
Cell Cycle Proteins/antagonists & inhibitors , Colorectal Neoplasms/drug therapy , Leukemia/drug therapy , Ovarian Neoplasms/drug therapy , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Proto-Oncogene Proteins/antagonists & inhibitors , Pyrazoles/pharmacology , Quinazolines/pharmacology , Administration, Oral , Animals , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , Dogs , Female , HL-60 Cells , Haplorhini , Humans , Leukemia/genetics , Leukemia/metabolism , Leukemia/pathology , Mice , Mice, Nude , Mice, SCID , Ovarian Neoplasms/genetics , Ovarian Neoplasms/metabolism , Rats , Xenograft Model Antitumor Assays , Polo-Like Kinase 1ABSTRACT
MPS1 kinase is a key regulator of the spindle assembly checkpoint (SAC), a mitotic mechanism specifically required for proper chromosomal alignment and segregation. It has been found aberrantly overexpressed in a wide range of human tumors and is necessary for tumoral cell proliferation. Here we report the identification and characterization of NMS-P715, a selective and orally bioavailable MPS1 small-molecule inhibitor, which selectively reduces cancer cell proliferation, leaving normal cells almost unaffected. NMS-P715 accelerates mitosis and affects kinetochore components localization causing massive aneuploidy and cell death in a variety of tumoral cell lines and inhibits tumor growth in preclinical cancer models. Inhibiting the SAC could represent a promising new approach to selectively target cancer cells.
Subject(s)
Antineoplastic Agents/pharmacology , Cell Cycle Proteins/antagonists & inhibitors , Mitosis/drug effects , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Pyrazoles/pharmacology , Quinazolines/pharmacology , Spindle Apparatus/drug effects , Aneuploidy , Animals , Antineoplastic Agents/chemistry , Cell Cycle Proteins/chemistry , Cell Growth Processes/drug effects , HCT116 Cells , HeLa Cells , Humans , Mice , Mice, Nude , Models, Molecular , Molecular Targeted Therapy/methods , Protein Kinase Inhibitors/chemistry , Protein Serine-Threonine Kinases/chemistry , Protein-Tyrosine Kinases , Xenograft Model Antitumor AssaysABSTRACT
Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase involved in the development of several human cancers and, as a result, is a recognized target for the development of small-molecule inhibitors for the treatment of ALK-positive malignancies. Here, we present the crystal structures of the unphosphorylated human ALK kinase domain in complex with the ATP competitive ligands PHA-E429 and NVP-TAE684. Analysis of these structures provides valuable information concerning the specific characteristics of the ALK active site as well as giving indications about how to obtain selective ALK inhibitors. In addition, the ALK-KD-PHA-E429 structure led to the identification of a potential regulatory mechanism involving a link made between a short helical segment immediately following the DFG motif and an N-terminal two-stranded beta-sheet. Finally, mapping of the activating mutations associated with neuroblastoma onto our structures may explain the roles these residues have in the activation process.