The non-receptor protein tyrosine phosphatase SHP2, encoded by PTPN11, has an important role in signal transduction downstream of growth factor receptor signalling and was the first reported ...oncogenic tyrosine phosphatase. Activating mutations of SHP2 have been associated with developmental pathologies such as Noonan syndrome and are found in multiple cancer types, including leukaemia, lung and breast cancer and neuroblastoma. SHP2 is ubiquitously expressed and regulates cell survival and proliferation primarily through activation of the RAS–ERK signalling pathway. It is also a key mediator of the programmed cell death 1 (PD-1) and B- and T-lymphocyte attenuator (BTLA) immune checkpoint pathways. Reduction of SHP2 activity suppresses tumour cell growth and is a potential target of cancer therapy. Here we report the discovery of a highly potent (IC50 = 0.071 μM), selective and orally bioavailable small-molecule SHP2 inhibitor, SHP099, that stabilizes SHP2 in an auto-inhibited conformation. SHP099 concurrently binds to the interface of the N-terminal SH2, C-terminal SH2, and protein tyrosine phosphatase domains, thus inhibiting SHP2 activity through an allosteric mechanism. SHP099 suppresses RAS–ERK signalling to inhibit the proliferation of receptor-tyrosine-kinase-driven human cancer cells in vitro and is efficacious in mouse tumour xenograft models. Together, these data demonstrate that pharmacological inhibition of SHP2 is a valid therapeutic approach for the treatment of cancers.
SHP2 is a nonreceptor protein tyrosine phosphatase encoded by the PTPN11 gene and is involved in cell growth and differentiation via the MAPK signaling pathway. SHP2 also plays an important role in ...the programed cell death pathway (PD-1/PD-L1). As an oncoprotein as well as a potential immunomodulator, controlling SHP2 activity is of high therapeutic interest. As part of our comprehensive program targeting SHP2, we identified multiple allosteric binding modes of inhibition and optimized numerous chemical scaffolds in parallel. In this drug annotation report, we detail the identification and optimization of the pyrazine class of allosteric SHP2 inhibitors. Structure and property based drug design enabled the identification of protein–ligand interactions, potent cellular inhibition, control of physicochemical, pharmaceutical and selectivity properties, and potent in vivo antitumor activity. These studies culminated in the discovery of TNO155, (3S,4S)-8-(6-amino-5-((2-amino-3-chloropyridin-4-yl)thio)pyrazin-2-yl)-3-methyl-2-oxa-8-azaspiro4.5decan-4-amine (1), a highly potent, selective, orally efficacious, and first-in-class SHP2 inhibitor currently in clinical trials for cancer.
SHP2 is a cytoplasmic protein tyrosine phosphatase encoded by the PTPN11 gene and is involved in cell proliferation, differentiation, and survival. Recently, we reported an allosteric mechanism of ...inhibition that stabilizes the auto-inhibited conformation of SHP2. SHP099 (1) was identified and characterized as a moderately potent, orally bioavailable, allosteric small molecule inhibitor, which binds to a tunnel-like pocket formed by the confluence of three domains of SHP2. In this report, we describe further screening strategies that enabled the identification of a second, distinct small molecule allosteric site. SHP244 (2) was identified as a weak inhibitor of SHP2 with modest thermal stabilization of the enzyme. X-ray crystallography revealed that 2 binds and stabilizes the inactive, closed conformation of SHP2, at a distinct, previously unexplored binding sitea cleft formed at the interface of the N-terminal SH2 and PTP domains. Derivatization of 2 using structure-based design resulted in an increase in SHP2 thermal stabilization, biochemical inhibition, and subsequent MAPK pathway modulation. Downregulation of DUSP6 mRNA, a downstream MAPK pathway marker, was observed in KYSE-520 cancer cells. Remarkably, simultaneous occupation of both allosteric sites by 1 and 2 was possible, as characterized by cooperative biochemical inhibition experiments and X-ray crystallography. Combining an allosteric site 1 inhibitor with an allosteric site 2 inhibitor led to enhanced pharmacological pathway inhibition in cells. This work illustrates a rare example of dual allosteric targeted protein inhibition, demonstrates screening methodology and tactics to identify allosteric inhibitors, and enables further interrogation of SHP2 in cancer and related pathologies.
Farnesyl diphosphate synthase catalyzes the sequential chain elongation reactions between isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) to form geranyl diphosphate (GPP) and ...between IPP and GPP to give farnesyl diphosphate (FPP). Bisubstrate analogues containing the allylic and homoallylic substrates were synthesized by joining fragments for IPP and the allylic diphosphates with a C–C bond between the methyl group at C3 in IPP and the Z-methyl group at C3 in DMAPP (3-OPP) and GPP (4-OPP), respectively. These constructs placed substantial limits on the conformational space available to the analogues relative to the two substrates. The key features of the synthesis of bisubstrate analogues 3-OPP and 4-OPP are a regioselective C-alkylation of the dianion of 3-methyl-3-buten-1-ol (5), a Z-selective cuprate addition of alkyl groups to an α,β-alkynyl ester intermediate, and differential activation of allylic and homoallylic alcohols in the analogues, followed by a simultaneous displacement of the leaving groups with tris(tetra-n-butylammonium) hydrogen diphosphate to give the corresponding bisdiphosphate analogues. The bisubstrate analogues were substrates for FPP synthase, giving novel seven-membered ring analogues of GPP and FPP. The catalytic efficiencies for cyclization of 3-OPP and 4-OPP were similar to those for chain elongation with IPP and DMAPP.
Overexpression of the antiapoptotic members of the Bcl-2 family of proteins is commonly associated with cancer cell survival and resistance to chemotherapeutics. Here, we describe the structure-based ...optimization of a series of N-heteroaryl sulfonamides that demonstrate potent mechanism-based cell death. The role of the acidic nature of the sulfonamide moiety as it relates to potency, solubility, and clearance is examined. This has led to the discovery of novel heterocyclic replacements for the acylsulfonamide core of ABT-737 and ABT-263.
Second-site NMR screening and linker design Jahnke, Wolfgang; Flörsheimer, Andreas; Blommers, Marcel J J ...
Current topics in medicinal chemistry,
2003, Letnik:
3, Številka:
1
Journal Article
Recenzirano
One of the prime merits of NMR as a tool for lead finding in drug discovery research is its sensitivity and robustness to detect weak protein-ligand interactions. This sensitivity allows to build up ...ligands for a given target in a modular way, by a fragment-based approach. In this approach, two ligands are seperately identified which bind to the target protein generally weakly, but at adjacent binding sites. In a next step, they are chemically linked to produce a high-affinity ligand. This review discusses methods to detect "second-site" ligands that bind to a protein in the presence of a "first-site" ligand, and methods to elucidate structural details on the spatial orientation of both ligands, so that chemical linkage is based on a large piece of experimental information. Published examples from second-site screening and linker design are summarized, and are complemented by previously unpublished in-house examples.
A series of N-hydroxy-3-phenyl-2-propenamides were prepared as novel inhibitors of human histone deacetylase (HDAC). These compounds were potent enzyme inhibitors, having IC50s < 400 nM in a ...partially purified enzyme assay. However, potency in cell growth inhibition assays ranged over 2 orders of magnitude in two human carcinoma cell lines. Selected compounds having cellular IC50 < 750 nM were tested for maximum tolerated dose (MTD) and for efficacy in the HCT116 human colon tumor xenograft assay. Four compounds having an MTD ≥ 100 mg/kg were selected for dose−response studies in the HCT116 xenograft model. One compound, 9 (NVP-LAQ824), had significant dose-related activity in the HCT116 colon and A549 lung tumor models, high MTD, and low gross toxicity. On the basis, in part, of these properties, 9 has entered human clinical trials in 2002.
Discipleship and evangelism in America today are eroding. Where traditionally the church sees discipleship and evangelism as separate entities, this research project argues for the unification of the ...two. This project explores “Evangelship,” the uniting of evangelism and discipleship, to see if the combined approach and perspective could offer a better way to engage the North American population. The driving question for this project is “Can the integration of evangelism and discipleship create a culture that accelerates and advances the Great Commission at U-Turn Covenant Church (U-Turn)?” To answer this question, the study aims to establish a discipleship framework that informs laity as to what Jesus meant by “go and make disciples of all nations” (Matt 28:19). The intent is to shift North American Christian culture to view evangelism not as an event but as a lifestyle that flows naturally out of discipleship. To establish this framework, the research observes four movements: from separation to integration, from event to (lifestyle) process, from specialization to equipping the saints, and from Latinos reaching Latinos (homogenous) to Latinos reaching diverse cultures (heterogenous). Emerging from this study, are eight principles that help create a culture of discipleship that leads towards evangelism. Using a quantitative method, an initiative was developed, and a pre- and post-test survey was created in order to test the efficacy in the construct of “Evangelship.” The significance of this study is that it provides a practical glance in how the integration of evangelism and discipleship can create a culture that influences better results in accelerating and advancing the Great Commission amongst laity who practice Evangelship as a lifestyle.
SHP2 is a nonreceptor protein tyrosine phosphatase (PTP) encoded by the PTPN11 gene involved in cell growth and differentiation via the MAPK signaling pathway. SHP2 also purportedly plays an ...important role in the programmed cell death pathway (PD-1/PD-L1). Because it is an oncoprotein associated with multiple cancer-related diseases, as well as a potential immunomodulator, controlling SHP2 activity is of significant therapeutic interest. Recently in our laboratories, a small molecule inhibitor of SHP2 was identified as an allosteric modulator that stabilizes the autoinhibited conformation of SHP2. A high throughput screen was performed to identify progressable chemical matter, and X-ray crystallography revealed the location of binding in a previously undisclosed allosteric binding pocket. Structure-based drug design was employed to optimize for SHP2 inhibition, and several new protein–ligand interactions were characterized. These studies culminated in the discovery of 6-(4-amino-4-methylpiperidin-1-yl)-3-(2,3-dichlorophenyl)pyrazin-2-amine (SHP099, 1), a potent, selective, orally bioavailable, and efficacious SHP2 inhibitor.
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