Concomitant inhibition
of multiple oncogenic pathways is a desirable
goal in cancer therapy. To achieve such an outcome with a single molecule
would simplify treatment regimes. Herein the core features of ruxolitinib
(1), a marketed JAK1/2 inhibitor, have been merged with
the HDAC inhibitor vorinostat (2), leading to new molecules
that are bispecific targeted JAK/HDAC inhibitors. A preferred pyrazole
substituted pyrrolopyrimidine, 24, inhibits JAK1 and
HDACs 1, 2, 3, 6, and 10 with IC50 values of less than
20 nM, is <100 nM potent against JAK2 and HDAC11, and is selective
for the JAK family against a panel of 97 kinases. Broad cellular antiproliferative
potency of 24 is supported by demonstration of JAK-STAT
and HDAC pathway blockade in hematological cell lines. Methyl analogue 45 has an even more selective profile. This study provides
new leads for assessment of JAK and HDAC pathway dual inhibiton achieved
with a single molecule.
Fragment screening, an emerging approach for hit finding in drug discovery, has recently been proven effective by its first approved drug, vemurafenib, for cancer treatment. Techniques such as nuclear magnetic resonance, surface plasmon resonance, and isothemal titration calorimetry, with their own pros and cons, have been employed for screening fragment libraries. As an alternative approach, screening based on high-performance liquid chromatography separation has been developed. In this work, we present weak affinity LC/MS as a method to screen fragments under high-throughput conditions. Affinity-based capillary columns with immobilized thrombin were used to screen a collection of 590 compounds from a fragment library. The collection was divided into 11 mixtures (each containing 35 to 65 fragments) and screened by MS detection. The primary screening was performed in <4 h (corresponding to >3500 fragments per day). Thirty hits were defined, which subsequently entered a secondary screening using an active site-blocked thrombin column for confirmation of specificity. One hit showed selective binding to thrombin with an estimated dissociation constant (K (D)) in the 0.1 mM range. This study shows that affinity LC/MS is characterized by high throughput, ease of operation, and low consumption of target and fragments, and therefore it promises to be a valuable method for fragment screening.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.