In our continuing effort devoted at developing agents targeting the EphA2 receptor by means of protein-protein interaction (PPI) inhibitors, we report here the design and synthesis of a new class of l-β-homotryptophan conjugates of 3-β-hydroxy-Δ-cholenic acid bearing a set of arylsulfonyl substituents at the indole nitrogen atom. An extensive structure-activity relationship (SAR) analysis indicates that the presence of a bulky lipophilic moiety at the indole nitrogen is fundamental for improving potency on the EphA2 receptor, while abrogating activity on the EphB1-EphB3 receptor subtypes. A rational exploration, guided by the combined application of an experimental design on σ and π physicochemical descriptors and docking simulations, led to the discovery of UniPR1454, a 1-(4-(trifluoromethyl)phenyl)sulfonyl derivative acting as potent and competitive EphA2 antagonist able to inhibit ephrin-A1 dependent signals and to reduce proliferation of glioblastoma (U251) cell line at micromolar concentration.
View Article and Find Full Text PDFFibroblast growth factors (FGFs) act as proangiogenic and mitogenic cytokines in several cancers, including multiple myeloma (MM). Indeed, corrupted FGF autocrine and paracrine secretion induces an aberrant activation of the FGF receptor (FGFR) signaling sustaining cancer cell spreading and resistance to pharmacological treatments. Thus, FGF traps may represent a promising anti-cancer strategy to hamper the ligand-dependent activation of the FGF/FGFR system.
View Article and Find Full Text PDFThe labeled ligand commonly employed in competition binding studies for melatonin receptor ligands, 2-[I]iodomelatonin, showed slow dissociation with different half-lives at the two receptor subtypes. This may affect the operational measures of affinity constants, which at short incubation times could not be obtained in equilibrium conditions, and structure-activity relationships, as the K values of tested ligands could depend on either interaction at the binding site or the dissociation path. To address these issues, the kinetic and saturation binding parameters of 2-[I]iodomelatonin as well as the competition constants for a series of representative ligands were measured at a short (2 h) and a long (20 h) incubation time.
View Article and Find Full Text PDFWith the aim of identifying novel antagonists selective for the EphA receptor family, a combined experimental and computational approach was taken to investigate the molecular basis of the recognition between a prototypical Eph-ephrin antagonist (UniPR1447) and two representative receptors of the EphA and EphB subfamilies, namely, EphA2 and EphB2 receptors. The conformational free-energy surface (FES) of the binding state of UniPR1447 within the ligand binding domain of EphA2 and EphB2, reconstructed from molecular dynamics (MD) simulations performed on the microsecond time scale, was exploited to drive the design and synthesis of a novel antagonist selective for EphA2 over the EphB2 receptor. The availability of compounds with this pharmacological profile will help discriminate the importance of these two receptors in the insurgence and progression of cancer.
View Article and Find Full Text PDFThe residence time (RT), the time for which a drug remains bound to its biological target, is a critical parameter for drug design. The prediction of this key kinetic property has been proven to be challenging and computationally demanding in the framework of atomistic simulations. In the present work, we setup and applied two distinct metadynamics protocols to estimate the RTs of muscarinic M3 receptor antagonists.
View Article and Find Full Text PDFIt is well demonstrated the key role of Eph-ephrin system, specifically of EphA2 receptor, in supporting tumor growth, invasion, metastasis and neovascularization. We previously identified FXR agonists as eligible antagonists of Eph-ephrin system. Herein we characterize new commercially available FXR (Farnesoid X Receptor) agonists as potential Eph ligands including Cilofexor, Nidufexor, Tropifexor, Turofexorate isopropyl and Vonafexor.
View Article and Find Full Text PDFTargeted covalent inhibitors hold promise for drug discovery, particularly for kinases. Targeting the catalytic lysine of epidermal growth factor receptor (EGFR) has attracted attention as a new strategy to overcome resistance due to the emergence of C797S mutation. Sulfonyl fluoride derivatives able to inhibit EGFR by sulfonylation of Lys745 have been reported.
View Article and Find Full Text PDFInhibition of monoglyceride lipase (MGL), also known as monoacylglycerol lipase (MAGL), has emerged as a promising approach for treating neurological diseases. To gain useful insights in the design of agents with balanced potency and reactivity, we investigated the mechanism of MGL carbamoylation by the reference triazole urea SAR629 (IC = 0.2 nM) and two recently described inhibitors featuring a pyrazole (IC = 1800 nM) or a 4-cyanopyrazole (IC = 8 nM) leaving group (LG), using a hybrid quantum mechanics/molecular mechanics (QM/MM) approach.
View Article and Find Full Text PDFIntroduction: The neurohormone melatonin (-acetyl-5-methoxytryptamine) regulates circadian rhythms exerting a variety of effects in the central nervous system and in periphery. These activities are mainly mediated by activation of MT and MT GPCRs. MT/MT agonist compounds are used clinically for insomnia, depression, and circadian rhythm disturbances.
View Article and Find Full Text PDFThe role of the Eph-ephrin system in the etiology of pathological conditions has been consolidated throughout the years. In this context, approaches directed against this signaling system, intended to modulate its activity, can be strategic therapeutic opportunities. Currently, the most promising class of compounds able to interfere with the Eph receptor-ephrin protein interaction is composed of synthetic derivatives of bile acids.
View Article and Find Full Text PDFThe transcriptional regulators YAP (Yes-associated protein) and TAZ (transcriptional co-activator with PDZ-binding motif) are the major downstream effectors in the Hippo pathway and are involved in cancer progression through modulation of the activity of TEAD (transcriptional enhanced associate domain) transcription factors. To exploit the advantages of drug repurposing in the search of new drugs, we developed a similar approach for the identification of new hits interfering with TEAD target gene expression. In our study, a 27-member in-house library was assembled, characterized, and screened for its cancer cell growth inhibition effect.
View Article and Find Full Text PDFWe report the evaluation of a small library of azole-bisindoles for their antileishmanial potential, in terms of efficacy on promastigotes and intracellular amastigotes. Nine compounds showed good activity on MHOM/TN/80/IPT1 promastigotes with IC values ranging from 4 to 10 μM. These active compounds were also tested on human (THP-1, HEPG2, HaCaT, and human primary fibroblasts) and canine (DH82) cell lines.
View Article and Find Full Text PDFThe effects of the neurohormone melatonin are mediated by the activation of the GPCRs MT and MT in a variety of tissues. Crystal structures suggest ligand access to the orthosteric binding site of MT and MT receptors through a lateral channel between transmembrane (TM) helices IV and V. We investigated the feasibility of this lipophilic entry route for 2-iodomelatonin, a nonselective agonist with a slower dissociation rate from the MT receptor, applying enhanced sampling simulations and free-energy calculations.
View Article and Find Full Text PDFThe emergence of the C797S mutation in EGFR is a frequent mechanism of resistance to osimertinib in the treatment of non-small cell lung cancer (NSCLC). In the present work, we report the design, synthesis and biochemical characterization of UPR1444 (compound 11), a new sulfonyl fluoride derivative which potently and irreversibly inhibits EGFR through the formation of a sulfonamide bond with the catalytic residue Lys745. Enzymatic assays show that compound 11 displayed an inhibitory activity on EGFR comparable to that of osimertinib, and it resulted more selective than the sulfonyl fluoride probe XO44, recently reported to inhibit a significant part of the kinome.
View Article and Find Full Text PDF-acylethanolamine acid amidase (NAAA) is an -terminal nucleophile (Ntn) hydrolase that catalyses the intracellular deactivation of the endogenous analgesic and anti-inflammatory agent palmitoylethanolamide (PEA). NAAA inhibitors counteract this process and exert marked therapeutic effects in animal models of pain, inflammation and neurodegeneration. While it is known that NAAA preferentially hydrolyses saturated fatty acid ethanolamides (FAEs), a detailed profile of the relationship between catalytic efficiency and fatty acid-chain length is still lacking.
View Article and Find Full Text PDFThird-generation inhibitors of the epidermal growth factor receptor (EGFR), best exemplified by osimertinib, have been developed to selectively target variants of EGFR bearing activating mutations and the mutation of gatekeeper T790 in patients with EGFR-mutated forms of Non-Small Cell Lung Cancer (NSCLC). While the application of third-generation inhibitors has represented an effective first- and second-line treatment, the efficacy of this class of inhibitors has been hampered by the novel, tertiary mutation C797S, which may occur after the treatment with osimertinib. More recently, other point mutations, including L718Q, G796D, G724S, L792 and G719, have emerged as mutations mediating resistance to third-generation inhibitors.
View Article and Find Full Text PDFIn the last years, the connection between the endocannabinoid system (eCS) and neuroprotection has been discovered, and evidence indicates that eCS signaling is involved in the regulation of cognitive processes and in the pathophysiology of Alzheimer's disease (AD). Accordingly, pharmacotherapy targeting eCS could represent a valuable contribution in fighting a multifaceted disease such as AD, opening a new perspective for the development of active agents with multitarget potential. In this paper, a series of coumarin-based carbamic and amide derivatives were designed and synthesized as multipotent compounds acting on cholinergic system and eCS-related targets.
View Article and Find Full Text PDFJ Enzyme Inhib Med Chem
December 2020
Heparanase is a validated target in cancer therapy and a potential target for several inflammatory pathologies. A ligand-based virtual screening of commercial libraries was performed to expand the chemical space of small-molecule inhibitors. The screening was based on similarity with known inhibitors and was performed in several runs, starting from literature compounds and progressing through newly discovered inhibitors.
View Article and Find Full Text PDF-anilinoethylamides are a class of melatoninergic agents with the aniline portion mimicking the indole ring of the natural ligand and the ethylamide chain reproducing that of melatonin. The simplest compound in this class, -{2-[(3-methoxyphenyl)methylamino]ethyl}acetamide (UCM793), has nanomolar binding affinity for MT and MT membrane receptors. To explore the effect of chain conformation on receptor binding, a methyl group was inserted on the methylene alpha or beta to the amide nitrogen and conformational equilibria were investigated by NMR spectroscopy and molecular dynamics simulations.
View Article and Find Full Text PDF-Acylethanolamine acid amidase (NAAA) is an N-terminal cysteine hydrolase primarily found in the endosomal-lysosomal compartment of innate and adaptive immune cells. NAAA catalyzes the hydrolytic deactivation of palmitoylethanolamide (PEA), a lipid-derived peroxisome proliferator-activated receptor-α (PPAR-α) agonist that exerts profound anti-inflammatory effects in animal models. Emerging evidence points to NAAA-regulated PEA signaling at PPAR-α as a critical control point for the induction and the resolution of inflammation and to NAAA itself as a target for anti-inflammatory medicines.
View Article and Find Full Text PDFQuantum mechanics/molecular mechanics (QM/MM) hybrid technique is emerging as a reliable computational method to investigate and characterize chemical reactions occurring in enzymes. From a drug discovery perspective, a thorough understanding of enzyme catalysis appears pivotal to assist the design of inhibitors able to covalently bind one of the residues belonging to the enzyme catalytic machinery. Thanks to the current advances in computer power, and the availability of more efficient algorithms for QM-based simulations, the use of QM/MM methodology is becoming a viable option in the field of covalent inhibitor design.
View Article and Find Full Text PDFThe EphA2 receptor has been validated in animal models as new target for treating tumors depending on angiogenesis and vasculogenic mimicry. In the present work, we extended our current knowledge on structure-activity relationship (SAR) data of two related classes of antagonists of the EphA2 receptor, namely 5β-cholan-24-oic acids and 5β-cholan-24-oyl l-β-homotryptophan conjugates, with the aim to develop new antiangiogenic compounds able to efficiently prevent the formation of blood vessels. As a result of our exploration, we identified UniPR505, N-[3α-(Ethylcarbamoyl)oxy-5β-cholan-24-oyl]-l-β-homo-tryptophan (compound 14), as a submicromolar antagonist of the EphA2 receptor capable to block EphA2 phosphorylation and to inhibit neovascularization in a chorioallantoic membrane (CAM) assay.
View Article and Find Full Text PDFThe interest on the role of gut microbiota in the biotransformation of drugs and xenobiotics has grown over the last decades and a deeper understanding of the mutual interactions is expected to help future improvements in the fields of drug development, toxicological risk assessment and precision medicine. In this paper, a microbiome drug metabolism case is presented, involving a lipophilic small molecule, N-(3β-hydroxy-Δ-cholen-24-oyl)-l-tryptophan, UniPR1331, active as antagonist of the Eph-ephrin system and effective in vivo in a murine orthotopic model of glioblastoma multiforme (GBM). Following the administration of a single 30 mg/kg dose (p.
View Article and Find Full Text PDFWe describe a set of benzisothiazolinone (BTZ) derivatives that are potent inhibitors of monoacylglycerol lipase (MGL), the primary degrading enzyme for the endocannabinoid 2-arachidonoyl--glycerol (2-AG). Structure-activity relationship studies evaluated various substitutions on the nitrogen atom and the benzene ring of the BTZ nucleus. Optimized derivatives with nanomolar potency allowed us to investigate the mechanism of MGL inhibition.
View Article and Find Full Text PDFHeparanase is the only mammalian endo-β-d-glucuronidase involved in a variety of major diseases. The up-regulation of heparanase expression increases tumor size, angiogenesis, and metastasis, representing a validated target in the anti-cancer field. To date, only a few small-molecule inhibitors have been described, but none have gotten through pre-clinical development.
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