Article pubs.acs.org/jmc
Discovery of a Highly Selective Tankyrase Inhibitor Displaying Growth Inhibition Effects against a Diverse Range of Tumor Derived Cell Lines Douglas W. Thomson,† Anne J. Wagner,† Marcus Bantscheff,† R. Edward Benson,‡,⊥ Lars Dittus,† Birgit Duempelfeld,† Gerard Drewes,† Jana Krause,† John T. Moore,‡,∇ Katrin Mueller,† Daniel Poeckel,† Christina Rau,† Elsa Salzer,† Lisa Shewchuk,§ Carsten Hopf,†,# John G. Emery,*,∥ and Marcel Muelbaier*,† †
Cellzome GmbH, A GlaxoSmithKline Company, Meyerhofstraße 1, 69117 Heidelberg, Germany GlaxoSmithKline, Research Triangle Park, 5 Moore Drive, North Carolina 27709, United States § Protein, Cellular & Structural Sciences, GlaxoSmithKline, 1250 South Collegeville Road, Upper Providence, Pennsylvania 19426, United States ∥ Virtual Proof of Concept DPU, GlaxoSmithKline, 709 Swedeland Road, King of Prussia, Pennsylvania 19406, United States ‡
S Supporting Information *
ABSTRACT: The availability of high quality probes for specific protein targets is fundamental to the investigation of their function and their validation as therapeutic targets. We report the utilization of a dedicated chemoproteomic assay platform combining affinity enrichment technology with highresolution protein mass spectrometry to the discovery of a novel nicotinamide isoster, the tetrazoloquinoxaline 41, a highly potent and selective tankyrase inhibitor. We also describe the use of 41 to investigate the biology of tankyrase, revealing the compound induced growth inhibition of a number of tumor derived cell lines, demonstrating the potential of tankyrase inhibitors in oncology.
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INTRODUCTION Tankyrases (TNKS1 and TNKS2) belong to the family of poly(ADP-ribose) polymerases (PARPs) and share high sequence and structural identities. They have overlapping functions playing a role in a diverse range of cellular functions, which have been the subject of comprehensive reviews.1−4 These functions include a role in telomere homeostasis,5 vesicle translocation,6,7 proteosomal assembly,8 mitosis,9−11 myelination of cells in the oligodendrocyte lineage,12,13 mediation of insulin-stimulated glucose uptake,6 and regulation of the Wnt/ β-catenin pathway.14−16 The relevance of a number of these pathways to cancer cell proliferation led to an increased interest in the discovery of new and selective TNKS inhibitors throughout academia and the drug discovery industry,14,17−30 and the discovery of TNKS inhibitors has been the subject of several excellent reviews.1,4,31−34 TNKS inhibitors can be grouped into two categories. First, those that bind to the nicotinamide binding site, such as 1 (XAV939).14 This compound was discovered in a phenotypic screening campaign searching for modulators of the Wnt/β-catenin signaling pathway and subsequently shown to mediate its effect through inhibition of TNKS. The second category of TNKS inhibitors is those that bind in the adenosine binding site inducing a shift in © 2017 American Chemical Society
the D-loop. An example of this class of TNKS inhibitor is 4((3aR,4S,7R,7aS)-1,3-dioxo-3a,4,7,7a-tetrahydro-1H-4,7-methanoisoindol-2(3H)-yl)-N-(quinolin-8-yl)benzamide (IWR-1), which was also first discovered as an inhibitor of the Wnt/βcatenin signaling pathway in a phenotypic high throughput screen.18,35,36 Finally, a set of dual-site TNKS inhibitors are described that simultaneously bind in both the nicotinamide and adenosine binding pockets, exemplified by the long quinazolinone series discovered by Bregman et al.23 Using our chemoproteomics technology,37−40 we discovered and characterized a selective tankyrase probe, which binds in the nicotinamide binding site, to aid in investigating the therapeutic potential of novel TNKS inhibitors. Chemoproteomic competition binding experiments enable the selectivity of a molecule to be determined against large sections of the proteome in a single experiment. Moreover, as cell or tissue extracts can be used as the protein source, this ensures close-to-physiological conditions as the assayed proteins are full length, post-translationally modified, and many protein−protein interactions remain intact. Together, Received: January 26, 2017 Published: June 7, 2017 5455
DOI: 10.1021/acs.jmedchem.7b00137 J. Med. Chem. 2017, 60, 5455−5471
Journal of Medicinal Chemistry
Article
Figure 1. Structures of TNKS inhibitors 1 and 2 and their selectivity against PARP family members determined using the TNKS-MS-assay (n = 2). 1 binds potently to TNKS1, TNKS2, and also PARP1. pIC50 for other family members detected was
