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.
The nuclear protein poly(ADP-ribose) polymerase-1 (PARP-1) has a well-established role in the signaling and repair of DNA and is a prominent target in oncology, as testified by the number of ...candidates in clinical testing that unselectively target both PARP-1 and its closest isoform PARP-2. The goal of our program was to find a PARP-1 selective inhibitor that would potentially mitigate toxicities arising from cross-inhibition of PARP-2. Thus, an HTS campaign on the proprietary Nerviano Medical Sciences (NMS) chemical collection, followed by SAR optimization, allowed us to discover 2-1-(4,4-difluorocyclohexyl)piperidin-4-yl-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide (NMS-P118, 20by). NMS-P118 proved to be a potent, orally available, and highly selective PARP-1 inhibitor endowed with excellent ADME and pharmacokinetic profiles and high efficacy in vivo both as a single agent and in combination with Temozolomide in MDA-MB-436 and Capan-1 xenograft models, respectively. Cocrystal structures of 20by with both PARP-1 and PARP-2 catalytic domain proteins allowed rationalization of the observed selectivity.
PARP inhibitors in cancer therapy: an update Papeo, Gianluca; Casale, Elena; Montagnoli, Alessia ...
Expert opinion on therapeutic patents,
04/2013, Letnik:
23, Številka:
4
Journal Article
Recenzirano
Inhibitors of the poly(ADP-ribose) polymerases (PARPs) family of proteins are currently being evaluated as potential anticancer medicines at both preclinical and clinical levels. They have the ...peculiarity to increase the efficacy of DNA-damaging agents and to selectively target tumor cells with specific DNA repair defects. This later development of these drugs should make it possible, in principle, to selectively target neoplastic vs healthy cells, thus realizing the Ehrlich's magic bullet concept of a personalized and tailored cure of diseases.
This review is designed to provide the readers with a brief summary and an update on PARP inhibitors in the oncology field, by covering the recent patent literature (2010 - 2012: and Questel Intellectual Property Portal QPat database search).
Presently, along with a number of preclinical candidates, there are eight PARP inhibitors in the clinic as either single agents or in combination with various chemotherapy and radiotherapy regimens. The tremendous efforts underneath those results testify the high interest on the target. The investigation and understanding of the cross-reactivity among members of the PARPs family as well as a deeper knowledge of their biological functions may lead to a more profound characterization of the PARP inhibitor's profile. This, in turn, will cast additional light on this exciting approach in treating cancer.
Abnormal proliferation mediated by disruption of the normal cell cycle mechanisms is a hallmark of virtually all cancer cells. Compounds targeting complexes between cyclin-dependent kinases (CDK) and ...cyclins, such as CDK2/cyclin A and CDK2/cyclin E, and inhibiting their kinase activity are regarded as promising antitumor agents to complement the existing therapies. From a high-throughput screening effort, we identified a new class of CDK2/cyclin A/E inhibitors. The hit-to-lead expansion of this class is described. X-ray crystallographic data of early compounds in this series, as well as in vitro testing funneled for rapidly achieving in vivo efficacy, led to a nanomolar inhibitor of CDK2/cyclin A (N-(5-cyclopropyl-1H-pyrazol-3-yl)-2-(2-naphthyl)acetamide (41), PNU-292137, IC50 = 37 nM) with in vivo antitumor activity (TGI > 50%) in a mouse xenograft model at a dose devoid of toxic effects.
We describe the synthesis of compounds with interesting biochemical and cellular characteristics. Optimization of the physico-chemical properties led to the identification of highly potent compound
...31 (PHA-793887), which presents remarkable in vivo efficacy.
We have recently reported CDK inhibitors based on the 6-substituted pyrrolo3,4-
cpyrazole core structure. Improvement of inhibitory potency against multiple CDKs, antiproliferative activity against cancer cell lines and optimization of the physico-chemical properties led to the identification of highly potent compounds. Compound
31 (PHA-793887) showed good efficacy in the human ovarian A2780, colon HCT-116 and pancreatic BX-PC3 carcinoma xenograft models and was well tolerated upon daily treatments by iv administration. It was identified as a drug candidate for clinical evaluation in patients with solid tumors.
The target landscape of clinical kinase drugs Klaeger, Susan; Heinzlmeir, Stephanie; Wilhelm, Mathias ...
Science (American Association for the Advancement of Science),
12/2017, Letnik:
358, Številka:
6367
Journal Article
Recenzirano
Odprti dostop
Kinase inhibitors are important cancer therapeutics. Polypharmacology is commonly observed, requiring thorough target deconvolution to understand drug mechanism of action. Using chemical proteomics, ...we analyzed the target spectrum of 243 clinically evaluated kinase drugs. The data revealed previously unknown targets for established drugs, offered a perspective on the "druggable" kinome, highlighted (non)kinase off-targets, and suggested potential therapeutic applications. Integration of phosphoproteomic data refined drug-affected pathways, identified response markers, and strengthened rationale for combination treatments. We exemplify translational value by discovering SIK2 (salt-inducible kinase 2) inhibitors that modulate cytokine production in primary cells, by identifying drugs against the lung cancer survival marker MELK (maternal embryonic leucine zipper kinase), and by repurposing cabozantinib to treat FLT3-ITD-positive acute myeloid leukemia. This resource, available via the ProteomicsDB database, should facilitate basic, clinical, and drug discovery research and aid clinical decision-making.
Src homology 2 (SH2) domains are key modules in intracellular signal transduction. They link activated cell surface receptors to downstream targets by binding to phosphotyrosine-containing sequence ...motifs. The crystal structure of a Grb2-SH2 domain−phosphopeptide complex was determined at 2.4 Å resolution. The asymmetric unit contains four polypeptide chains. There is an unexpected domain swap so that individual chains do not adopt a closed SH2 fold. Instead, reorganization of the EF loop leads to an open, nonglobular fold, which associates with an equivalent partner to generate an intertwined dimer. As in previously reported crystal structures of canonical Grb2-SH2 domain−peptide complexes, each of the four hybrid SH2 domains in the two domain-swapped dimers binds the phosphopeptide in a type I β-turn conformation. This report is the first to describe domain swapping for an SH2 domain. While in vivo evidence of dimerization of Grb2 exists, our SH2 dimer is metastable and a physiological role of this new form of dimer formation remains to be demonstrated.
We previously demonstrated that natural product‐inspired 3,4‐dihydropyrrolo1,2‐apyrazin‐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.
We previously demonstrated that natural product‐inspired 3,4‐dihydropyrrolo1,2‐apyrazin‐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.
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