16 research outputs found
Structure-Based Design of Novel Class II c-Met Inhibitors: 1. Identification of Pyrazolone-Based Derivatives
Deregulation of c-Met receptor tyrosine kinase activity
leads to
tumorigenesis and metastasis in animal models. More importantly, the
identification of activating mutations in c-Met, as well as <i>MET</i> gene amplification in human cancers, points to c-Met
as an important target for cancer therapy. We have previously described
two classes of c-Met kinase inhibitors (class I and class II) that
differ in their binding modes and selectivity profiles. The class
II inhibitors tend to have activities on multiple kinases. Knowledge
of the binding mode of these molecules in the c-Met protein led to
the design and evaluation of several new class II c-Met inhibitors
that utilize various 5-membered cyclic carboxamides to conformationally
restrain key pharmacophoric groups within the molecule. These investigations
resulted in the identification of a potent and novel class of pyrazolone
c-Met inhibitors with good in vivo activity
Discovery of Potent and Selective 8‑Fluorotriazolopyridine c‑Met Inhibitors
The overexpression of c-Met and/or
hepatocyte growth factor (HGF),
the amplification of the MET gene, and mutations in the c-Met kinase
domain can activate signaling pathways that contribute to cancer progression
by enabling tumor cell proliferation, survival, invasion, and metastasis.
Herein, we report the discovery of 8-fluorotriazolopyridines as inhibitors
of c-Met activity. Optimization of the 8-fluorotriazolopyridine scaffold
through the combination of structure-based drug design, SAR studies,
and metabolite identification provided potent (cellular IC<sub>50</sub> < 10 nM), selective inhibitors of c-Met with desirable pharmacokinetic
properties that demonstrate potent inhibition of HGF-mediated c-Met
phosphorylation in a mouse liver pharmacodynamic model
Phamacokinetic and pharmacodynamic properties of compound A <i>in vivo</i>.
<p>Compound A was administered to athymic nude mice by oral gavage. At the indicated time points, blood was collected and plasma levels of compound A (left panel) as well as S1P (right panel) were determined. Compound levels were corrected for binding to murine plasma, and concentrations of free compound A is depicted in this graph. *P<0.05 compared to vehicle.</p
Inhibition of cellular SPHK activity in tumor cell lines.
<p>Two hours after addition of C17 sphingosine, cells were lysed and levels of C17 S1P were determined.</p
siRNA experiments in A375 cells.
<p>SPHK1 (panel A) and SPHK2 (panel B) as well as the cytotoxic controls PLK1 and POLR2A were targeted with numerous siRNAs in the melanoma cell line A375. Each vertical line represents the effects of an individual siRNA transfection on relative cell viability, with negative values representing cell killing. Statistical significance was calculated as described in Materials and Methods.</p
Correlation between SPHK inhibition and cell viability.
<p>A panel of 18 compounds structurally related to compounds A and B was tested in biochemical hSPHK1 assays (inflection point IC<sub>50</sub>s plotted on x-axis) and 72 h viability assays in WM266.4 cells (inflection point IC<sub>50</sub>s plotted on y-axis).</p
Effects of SPHK inhibition on cell viability.
<p>The human melanoma cell line WM266.4 (panel A) and the human glioblastoma cell line LN229 (panel B) were treated for 72 h with the indicated concentrations of compound A (left panel) and compound B (right panel). Viability was assessed after 72 h.</p
Effects of SPHK inhibition in colony formation assays.
<p>LN229 cells were seeded at a density of 800 cells/well in a six well plate in the presence of the indicated concentrations of SPHK inhibitor. After 15 days, cells were fixed and stained with crystal violet.</p
Discovery of (<i>R</i>)‑6-(1-(8-Fluoro-6-(1-methyl‑1<i>H</i>‑pyrazol-4-yl)-[1,2,4]triazolo[4,3‑<i>a</i>]pyridin-3-yl)ethyl)-3-(2-methoxyethoxy)-1,6-naphthyridin-5(6<i>H</i>)‑one (AMG 337), a Potent and Selective Inhibitor of MET with High Unbound Target Coverage and Robust In Vivo Antitumor Activity
Deregulation
of the receptor tyrosine kinase mesenchymal epithelial
transition factor (MET) has been implicated in several human cancers
and is an attractive target for small molecule drug discovery. Herein,
we report the discovery of compound <b>23</b> (AMG 337), which
demonstrates nanomolar inhibition of MET kinase activity, desirable
preclinical pharmacokinetics, significant inhibition of MET phosphorylation
in mice, and robust tumor growth inhibition in a MET-dependent mouse
efficacy model
Inhibition of human and murine SPHK activity in biochemical assays.
<p>Inhibition of human and murine SPHK activity in biochemical assays.</p