Publications by authors named "Barbara Forte"

16 Publications

  • Page 1 of 1

Lysyl-tRNA synthetase as a drug target in malaria and cryptosporidiosis.

Proc Natl Acad Sci U S A 2019 04 20;116(14):7015-7020. Epub 2019 Mar 20.

Wellcome Centre for Anti-Infectives Research, Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, University of Dundee, DD1 5EH Dundee, United Kingdom;

Malaria and cryptosporidiosis, caused by apicomplexan parasites, remain major drivers of global child mortality. New drugs for the treatment of malaria and cryptosporidiosis, in particular, are of high priority; however, there are few chemically validated targets. The natural product cladosporin is active against blood- and liver-stage and in cell-culture studies. Target deconvolution in has shown that cladosporin inhibits lysyl-tRNA synthetase (KRS1). Here, we report the identification of a series of selective inhibitors of apicomplexan KRSs. Following a biochemical screen, a small-molecule hit was identified and then optimized by using a structure-based approach, supported by structures of both KRS1 and KRS (KRS). In vivo proof of concept was established in an SCID mouse model of malaria, after oral administration (ED = 1.5 mg/kg, once a day for 4 d). Furthermore, we successfully identified an opportunity for pathogen hopping based on the structural homology between KRS1 and KRS. This series of compounds inhibit KRS and and in culture, and our lead compound shows oral efficacy in two cryptosporidiosis mouse models. X-ray crystallography and molecular dynamics simulations have provided a model to rationalize the selectivity of our compounds for KRS1 and KRS vs. (human) KRS. Our work validates apicomplexan KRSs as promising targets for the development of drugs for malaria and cryptosporidiosis.
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http://dx.doi.org/10.1073/pnas.1814685116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6452685PMC
April 2019

LEADeR role of miR-205 host gene as long noncoding RNA in prostate basal cell differentiation.

Nat Commun 2019 01 18;10(1):307. Epub 2019 Jan 18.

Department of Applied Research and Technological Development, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, 20133, Italy.

Though miR-205 function has been largely characterized, the nature of its host gene, MIR205HG, is still completely unknown. Here, we show that only lowly expressed alternatively spliced MIR205HG transcripts act as de facto pri-miRNAs, through a process that involves Drosha to prevent unfavorable splicing and directly mediate miR-205 excision. Notably, MIR205HG-specific processed transcripts revealed to be functional per se as nuclear long noncoding RNA capable of regulating differentiation of human prostate basal cells through control of the interferon pathway. At molecular level, MIR205HG directly binds the promoters of its target genes, which have an Alu element in proximity of the Interferon-Regulatory Factor (IRF) binding site, and represses their transcription likely buffering IRF1 activity, with the ultimate effect of preventing luminal differentiation. As MIR205HG functions autonomously from (albeit complementing) miR-205 in preserving the basal identity of prostate epithelial cells, it warrants reannotation as LEADeR (Long Epithelial Alu-interacting Differentiation-related RNA).
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http://dx.doi.org/10.1038/s41467-018-08153-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6338800PMC
January 2019

Biochemical and Structural Characterization of Selective Allosteric Inhibitors of the Plasmodium falciparum Drug Target, Prolyl-tRNA-synthetase.

ACS Infect Dis 2017 01 16;3(1):34-44. Epub 2016 Nov 16.

Center for Emerging and Reemerging Infectious Disease (CERID), University of Washington , 750 Republican Street, Seattle, Washington 98109, United States.

Plasmodium falciparum (Pf) prolyl-tRNA synthetase (ProRS) is one of the few chemical-genetically validated drug targets for malaria, yet highly selective inhibitors have not been described. In this paper, approximately 40,000 compounds were screened to identify compounds that selectively inhibit PfProRS enzyme activity versus Homo sapiens (Hs) ProRS. X-ray crystallography structures were solved for apo, as well as substrate- and inhibitor-bound forms of PfProRS. We identified two new inhibitors of PfProRS that bind outside the active site. These two allosteric inhibitors showed >100 times specificity for PfProRS compared to HsProRS, demonstrating this class of compounds could overcome the toxicity related to HsProRS inhibition by halofuginone and its analogues. Initial medicinal chemistry was performed on one of the two compounds, guided by the cocrystallography of the compound with PfProRS, and the results can instruct future medicinal chemistry work to optimize these promising new leads for drug development against malaria.
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http://dx.doi.org/10.1021/acsinfecdis.6b00078DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5241706PMC
January 2017

Dissecting the role of microRNAs in prostate cancer metastasis: implications for the design of novel therapeutic approaches.

Cell Mol Life Sci 2016 07 12;73(13):2531-42. Epub 2016 Mar 12.

Molecular Pharmacology Unit, Department of Experimental Oncology and Molecular Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, 20133, Milan, Italy.

Metastatic prostate cancer is a lethal disease that remains incurable despite the recent approval of new drugs, thus making the development of alternative treatment approaches urgently needed. A more precise understanding of the molecular mechanisms underlying prostate cancer dissemination could lead to the identification of novel therapeutic targets for the design of efficient anti-metastatic strategies. MicroRNA (miRNAs) are endogenous, small non-coding RNA molecules acting as key regulators of gene expression at post-transcriptional level. It has been clearly established that altered miRNA expression is a common hallmark of cancer. In addition, emerging evidence suggests their direct involvement in the metastatic cascade. In this review, we present a comprehensive overview of the data generated in experimental tumor models indicating that specific miRNAs may impinge on the different stages of prostate cancer metastasis, including (i) the regulation of epithelial-to-mesenchymal transition and cell migration/invasion, (ii) the interplay between cancer cells and the surrounding stroma, (iii) the control of angiogenesis, (iv) the regulation of anoikis, and (v) the colonization of distant organs. Moreover, we show preliminary evidence of the clinical relevance of some of these miRNAs, in terms of association with tumor aggressiveness/dissemination and clinical outcome, as emerged from translation studies carried out in prostate cancer patient cohorts. We also discuss the potential and the current limitations of manipulating metastasis-related miRNAs, by mimicking or inhibiting them, as a strategy for the development of novel therapeutic approaches for the advanced disease.
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http://dx.doi.org/10.1007/s00018-016-2176-3DOI Listing
July 2016

Discovery of 2-[1-(4,4-Difluorocyclohexyl)piperidin-4-yl]-6-fluoro-3-oxo-2,3-dihydro-1H-isoindole-4-carboxamide (NMS-P118): A Potent, Orally Available, and Highly Selective PARP-1 Inhibitor for Cancer Therapy.

J Med Chem 2015 Sep 26;58(17):6875-98. Epub 2015 Aug 26.

Oncology, Nerviano Medical Sciences Srl , Viale Pasteur 10, 20014 Nerviano, Milan, Italy.

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.
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http://dx.doi.org/10.1021/acs.jmedchem.5b00680DOI Listing
September 2015

Structural insight into maternal embryonic leucine zipper kinase (MELK) conformation and inhibition toward structure-based drug design.

Biochemistry 2013 Sep 4;52(37):6380-7. Epub 2013 Sep 4.

Nerviano Medical Sciences , Viale Pasteur 10, 20014 Nerviano, Milan, Italy.

Maternal embryonic leucine zipper kinase (MELK) is upregulated in several types of tumor, including breast, prostate, and brain tumors. Its expression is generally associated with cell survival, cell proliferation, and resistance to apoptosis. Therefore, the potential of MELK inhibitors as therapeutic agents is recently attracting considerable interest. Here we report the first structures of MELK in complex with AMP-PNP and with nanomolar inhibitors. Our studies shed light on the role of the MELK UBA domain, provide a characterization of the kinase active site, and identify key residues for achieving high potency, laying the groundwork for structure-based drug design efforts.
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http://dx.doi.org/10.1021/bi4005864DOI Listing
September 2013

NMS-P937, a 4,5-dihydro-1H-pyrazolo[4,3-h]quinazoline derivative as potent and selective Polo-like kinase 1 inhibitor.

Bioorg Med Chem Lett 2011 May 21;21(10):2969-74. Epub 2011 Mar 21.

Nerviano Medical Sciences srl, Business Unit Oncology, Viale Pasteur 10, 20014 Nerviano, MI, Italy.

As part of our drug discovery effort, we identified and developed 4,5-dihydro-1H-pyrazolo[4,3-h]quinazoline derivatives as PLK1 inhibitors. We now report the optimization of this class that led to the identification of NMS-P937, a potent, selective and orally available PLK1 inhibitor. Also, in order to understand the source of PLK1 selectivity, we determined the crystal structure of PLK1 with NMS-P937. The compound was active in vivo in HCT116 xenograft model after oral administration and is presently in Phase I clinical trials evaluation.
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http://dx.doi.org/10.1016/j.bmcl.2011.03.054DOI Listing
May 2011

Cdc7 kinase inhibitors: 5-heteroaryl-3-carboxamido-2-aryl pyrroles as potential antitumor agents. 1. Lead finding.

J Med Chem 2010 Oct;53(20):7296-315

Nerviano Medical Sciences Srl, Business Unit Oncology, Viale Pasteur 10, 20014 Nerviano, MI, Italy.

Cdc7 serine/threonine kinase is a key regulator of DNA synthesis in eukaryotic organisms. Cdc7 inhibition through siRNA or prototype small molecules causes p53 independent apoptosis in tumor cells while reversibly arresting cell cycle progression in primary fibroblasts. This implies that Cdc7 kinase could be considered a potential target for anticancer therapy. We previously reported that pyrrolopyridinones (e.g., 1) are potent and selective inhibitors of Cdc7 kinase, with good cellular potency and in vitro ADME properties but with suboptimal pharmacokinetic profiles. Here we report on a new chemical class of 5-heteroaryl-3-carboxamido-2-substituted pyrroles (1A) that offers advantages of chemistry diversification and synthetic simplification. This work led to the identification of compound 18, with biochemical data and ADME profile similar to those of compound 1 but characterized by superior efficacy in an in vivo model. Derivative 18 represents a new lead compound worthy of further investigation toward the ultimate goal of identifying a clinical candidate.
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http://dx.doi.org/10.1021/jm100504dDOI Listing
October 2010

Thieno[3,2-c]pyrazoles: a novel class of Aurora inhibitors with favorable antitumor activity.

Bioorg Med Chem 2010 Oct 25;18(19):7113-20. Epub 2010 Jul 25.

Nerviano Medical Sciences-Oncology, via Pasteur 10, 20014 Nerviano, Milan, Italy.

A novel series of 3-amino-1H-thieno[3,2-c]pyrazole derivatives demonstrating high potency in inhibiting Aurora kinases was developed. Here we describe the synthesis and a preliminary structure-activity relationship, which led to the discovery of a representative compound (38), which showed low nanomolar inhibitory activity in the anti-proliferation assay and was able to block the cell cycle in HCT-116 cell line. This compound demonstrated favorable pharmacokinetic properties and good efficacy in the HL-60 xenograft tumor model.
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http://dx.doi.org/10.1016/j.bmc.2010.07.048DOI Listing
October 2010

A submarine journey: the pyrrole-imidazole alkaloids.

Mar Drugs 2009 Nov 27;7(4):705-53. Epub 2009 Nov 27.

Department of Medicinal Chemistry, Nerviano Medical Sciences, Viale Pasteur 10, Nerviano, Milan, Italy.

In his most celebrated tale "The Picture of Dorian Gray", Oscar Wilde stated that "those who go beneath the surface do so at their peril". This sentence could be a prophetical warning for the practitioner who voluntarily challenges himself with trying to synthesize marine sponge-deriving pyrrole-imidazole alkaloids. This now nearly triple-digit membered community has been growing exponentially in the last 20 years, both in terms of new representatives and topological complexity--from simple, achiral oroidin to the breathtaking 12-ring stylissadines A and B, each possessing 16 stereocenters. While the biosynthesis and the role in the sponge economy of most of these alkaloids still lies in the realm of speculations, significant biological activities for some of them have clearly emerged. This review will account for the progress in achieving the total synthesis of the more biologically enticing members of this class of natural products.
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http://dx.doi.org/10.3390/md7040705DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2810223PMC
November 2009

Poly(ADP-ribose) polymerase inhibition in cancer therapy: are we close to maturity?

Expert Opin Ther Pat 2009 Oct;19(10):1377-400

Department of Medicinal Chemistry, Nerviano Medical Sciences, Viale Pasteur 10, Nerviano (MI), Italy.

Background: During the last few years an increasing number of poly(ADP-ribose) polymerase (PARP) inhibitors have been appearing in the context of cancer therapy. This is mainly due to a better knowledge of the best-characterized member of the PARP family of enzymes, PARP-1, further reinforced by the recognition of the clinical benefits arising from its inhibition.

Objective/method: The aim of this review is to give the reader an update on PARP inhibition in cancer therapy, by covering both the scientific (SciFinder) search) and the patent literature (Chemical Abstract/Derwent search) published recently (2005-2008).

Conclusions: More patient-compliant orally available PARP-1 inhibitor clinical candidates, along with their possible use as single agents in specific, molecularly defined cancer indications, increase the expectations for this therapeutic approach. The growing understanding of the biological role of other PARPs, such as Tankyrase 1, may be of interest as new potential targets. Besides the classical NAD-mimicking pharmacophore, additional compounds, which either do not resemble nicotinamide or exploit different binding sites, are emerging.
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http://dx.doi.org/10.1517/13543770903215883DOI Listing
October 2009

A straightforward total synthesis of (-)-chaetominine.

Chemistry 2009 Aug;15(32):7922-9

Chemical Core Technologies, Nerviano Medical Sciences, Viale Pasteur 10, 20014 Nerviano (MI), Italy.

A total synthesis of the tripeptide alkaloid (-)-chaetominine (1) was achieved in 9.3% overall yield starting from commercially available D-tryptophan methyl ester, based on a short and straightforward (nine steps) sequence. The early stage introduction (first step) of the quinazolinone moiety and the late stage introduction (penultimate step) of the hydroxy group allowed a synthetic strategy devoid of protective groups. The key step of the process is the a-c tricyclic ring construction via an unprecedented NCS-mediated N-acyl cyclization on an indole ring to give tetrahydro-1H-pyrido[2,3-b]indole 11. In the penultimate step, oxidation of the tetracyclic intermediate 14 with oxaziridine 15 gave only one of the four possible diastereoisomers, the cis-diastereoisomer 16 resulting from the attack of the oxaziridine to the double bond face opposite to the c-d ring substituents. In the last step, the complete stereocontrol of the Et(3)SiH/TFA reduction of compound 16, probably involving a N-acyliminium ion, can be attributed to ring constrain, which forces the b-c ring junction in the more stable cis-orientation. (-)-Chaetominine (1) showed a negligible inhibitory activity on several cancer cell lines.
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http://dx.doi.org/10.1002/chem.200900793DOI Listing
August 2009

First Cdc7 kinase inhibitors: pyrrolopyridinones as potent and orally active antitumor agents. 2. Lead discovery.

J Med Chem 2009 Jan;52(2):293-307

Nerviano Medical Sciences Srl, Viale Pasteur 10, 20014 Nerviano, Milano, Italy.

Cdc7 kinase is a key regulator of the S-phase of the cell cycle, known to promote the activation of DNA replication origins in eukaryotic organisms. Cdc7 inhibition can cause tumor-cell death in a p53-independent manner, supporting the rationale for developing Cdc7 inhibitors for the treatment of cancer. In this paper, we conclude the structure-activity relationships study of the 2-heteroaryl-pyrrolopyridinone class of compounds that display potent inhibitory activity against Cdc7 kinase. Furthermore, we also describe the discovery of 89S, [(S)-2-(2-aminopyrimidin-4-yl)-7-(2-fluoro-ethyl)-1,5,6,7-tetrahydropyrrolo[3,2-c]pyridin-4-one], as a potent ATP mimetic inhibitor of Cdc7. Compound 89S has a Ki value of 0.5 nM, inhibits cell proliferation of different tumor cell lines with an IC50 in the submicromolar range, and exhibits in vivo tumor growth inhibition of 68% in the A2780 xenograft model.
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http://dx.doi.org/10.1021/jm800977qDOI Listing
January 2009

Cdc7 kinase inhibitors: pyrrolopyridinones as potential antitumor agents. 1. Synthesis and structure-activity relationships.

J Med Chem 2008 Feb 18;51(3):487-501. Epub 2008 Jan 18.

Nerviano Medical Sciences Srl, Viale Pasteur 10, 20014 Nerviano, Milano, Italy.

Cdc7 kinase is an essential protein that promotes DNA replication in eukaryotic organisms. Genetic evidence indicates that Cdc7 inhibition can cause selective tumor-cell death in a p53-independent manner, supporting the rationale for developing Cdc7 small-molecule inhibitors for the treatment of cancers. In this paper, the synthesis and structure-activity relationships of 2-heteroaryl-pyrrolopyridinones, the first potent Cdc7 kinase inhibitors, are described. Starting from 2-pyridin-4-yl-1,5,6,7-tetrahydro-pyrrolo[3,2-c]pyridin-4-one, progress toward a simple scaffold, tailored for Cdc7 inhibition, is reported.
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http://dx.doi.org/10.1021/jm700956rDOI Listing
February 2008

1,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles: identification of a potent Aurora kinase inhibitor with a favorable antitumor kinase inhibition profile.

J Med Chem 2006 Nov;49(24):7247-51

Nerviano Medical Sciences S.r.l. viale Pasteur 10, 20014 Nerviano, Milan, Italy.

The optimization of a series of 5-phenylacetyl 1,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole derivatives toward the inhibition of Aurora kinases led to the identification of compound 9d. This is a potent inhibitor of Aurora kinases that also shows low nanomolar potency against additional anticancer kinase targets. Based on its high antiproliferative activity on different cancer cell lines, favorable chemico-physical and pharmacokinetic properties, and high efficacy in in vivo tumor models, compound 9d was ultimately selected for further development.
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http://dx.doi.org/10.1021/jm060897wDOI Listing
November 2006

Potent and selective Aurora inhibitors identified by the expansion of a novel scaffold for protein kinase inhibition.

J Med Chem 2005 Apr;48(8):3080-4

Nerviano Medical Sciences - Oncology, via Pasteur 10, 20014 Nerviano, Milan, Italy.

Potent and selective Aurora kinase inhibitors were identified from the combinatorial expansion of the 1,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole bi-cycle, a novel and versatile scaffold designed to target the ATP pocket of protein kinases. The most potent compound reported in this study had an IC(50) of 0.027 microM in the enzymatic assay for Aur-A inhibition and IC(50)s between 0.05 microM and 0.5 microM for the inhibition of proliferation of different tumor cell lines.
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http://dx.doi.org/10.1021/jm049076mDOI Listing
April 2005