4 research outputs found
Comparative Analysis of Drug-like EP300/CREBBP Acetyltransferase Inhibitors
The
human acetyltransferase paralogues EP300 and CREBBP are master
regulators of lysine acetylation whose activity has been implicated
in various cancers. In the half-decade since the first drug-like inhibitors
of these proteins were reported, three unique molecular scaffolds
have taken precedent: an indane spiro-oxazolidinedione (A-485), a
spiro-hydantoin (iP300w), and an aminopyridine (CPI-1612). Despite
increasing use of these molecules to study lysine acetylation, the
dearth of data regarding their relative biochemical and biological
potencies makes their application as chemical probes a challenge.
To address this gap, here we present a comparative study of drug-like
EP300/CREBBP acetyltransferase inhibitors. First, we determine the
biochemical and biological potencies of A-485, iP300w, and CPI-1612,
highlighting the increased potencies of the latter two compounds at
physiological acetyl-CoA concentrations. Cellular evaluation shows
that inhibition of histone acetylation and cell growth closely aligns
with the biochemical potencies of these molecules, consistent with
an on-target mechanism. Finally, we demonstrate the utility of comparative
pharmacology by using it to investigate the hypothesis that increased
CoA synthesis caused by knockout of PANK4 can competitively antagonize
the binding of EP300/CREBBP inhibitors and demonstrate proof-of-concept
photorelease of a potent inhibitor molecule. Overall, our study demonstrates
how knowledge of the relative inhibitor potency can guide the study
of EP300/CREBBP-dependent mechanisms and suggests new approaches to
target delivery, thus broadening the therapeutic window of these preclinical
epigenetic drug candidates
Comparative Analysis of Drug-like EP300/CREBBP Acetyltransferase Inhibitors
The
human acetyltransferase paralogues EP300 and CREBBP are master
regulators of lysine acetylation whose activity has been implicated
in various cancers. In the half-decade since the first drug-like inhibitors
of these proteins were reported, three unique molecular scaffolds
have taken precedent: an indane spiro-oxazolidinedione (A-485), a
spiro-hydantoin (iP300w), and an aminopyridine (CPI-1612). Despite
increasing use of these molecules to study lysine acetylation, the
dearth of data regarding their relative biochemical and biological
potencies makes their application as chemical probes a challenge.
To address this gap, here we present a comparative study of drug-like
EP300/CREBBP acetyltransferase inhibitors. First, we determine the
biochemical and biological potencies of A-485, iP300w, and CPI-1612,
highlighting the increased potencies of the latter two compounds at
physiological acetyl-CoA concentrations. Cellular evaluation shows
that inhibition of histone acetylation and cell growth closely aligns
with the biochemical potencies of these molecules, consistent with
an on-target mechanism. Finally, we demonstrate the utility of comparative
pharmacology by using it to investigate the hypothesis that increased
CoA synthesis caused by knockout of PANK4 can competitively antagonize
the binding of EP300/CREBBP inhibitors and demonstrate proof-of-concept
photorelease of a potent inhibitor molecule. Overall, our study demonstrates
how knowledge of the relative inhibitor potency can guide the study
of EP300/CREBBP-dependent mechanisms and suggests new approaches to
target delivery, thus broadening the therapeutic window of these preclinical
epigenetic drug candidates
Comparative Analysis of Drug-like EP300/CREBBP Acetyltransferase Inhibitors
The
human acetyltransferase paralogues EP300 and CREBBP are master
regulators of lysine acetylation whose activity has been implicated
in various cancers. In the half-decade since the first drug-like inhibitors
of these proteins were reported, three unique molecular scaffolds
have taken precedent: an indane spiro-oxazolidinedione (A-485), a
spiro-hydantoin (iP300w), and an aminopyridine (CPI-1612). Despite
increasing use of these molecules to study lysine acetylation, the
dearth of data regarding their relative biochemical and biological
potencies makes their application as chemical probes a challenge.
To address this gap, here we present a comparative study of drug-like
EP300/CREBBP acetyltransferase inhibitors. First, we determine the
biochemical and biological potencies of A-485, iP300w, and CPI-1612,
highlighting the increased potencies of the latter two compounds at
physiological acetyl-CoA concentrations. Cellular evaluation shows
that inhibition of histone acetylation and cell growth closely aligns
with the biochemical potencies of these molecules, consistent with
an on-target mechanism. Finally, we demonstrate the utility of comparative
pharmacology by using it to investigate the hypothesis that increased
CoA synthesis caused by knockout of PANK4 can competitively antagonize
the binding of EP300/CREBBP inhibitors and demonstrate proof-of-concept
photorelease of a potent inhibitor molecule. Overall, our study demonstrates
how knowledge of the relative inhibitor potency can guide the study
of EP300/CREBBP-dependent mechanisms and suggests new approaches to
target delivery, thus broadening the therapeutic window of these preclinical
epigenetic drug candidates
Discovery of Novel Small-Molecule Scaffolds for the Inhibition and Activation of WIP1 Phosphatase from a RapidFire Mass Spectrometry High-Throughput Screen
Wild-type
P53-induced phosphatase 1 (WIP1), also known as PPM1D or PP2Cδ, is a serine/threonine protein phosphatase
induced by P53 after genotoxic stress. WIP1 inhibition has been proposed
as a therapeutic strategy for P53 wild-type cancers in which it is
overexpressed, but this approach would be ineffective in P53-negative
cancers. Furthermore, there are several cancers with mutated P53 where
WIP1 acts as a tumor suppressor. Therefore, activating WIP1 phosphatase
might also be a therapeutic strategy, depending on the P53 status.
To date, no specific, potent WIP1 inhibitors with appropriate pharmacokinetic
properties have been reported, nor have WIP1-specific activators.
Here, we report the discovery of new WIP1 modulators from a high-throughput
screen (HTS) using previously described orthogonal biochemical assays
suitable for identifying both inhibitors and activators. The primary
HTS was performed against a library of 102 277 compounds at
a single concentration using a RapidFire mass spectrometry assay.
Hits were further evaluated over a range of 11 concentrations with
both the RapidFire MS assay and an orthogonal fluorescence-based assay.
Further biophysical, biochemical, and cell-based studies of confirmed
hits revealed a WIP1 activator and two inhibitors, one competitive
and one uncompetitive. These new scaffolds are prime candidates for
optimization which might enable inhibitors with improved pharmacokinetics
and a first-in-class WIP1 activator