Discovery of novel class of histone deacetylase inhibitors as potential anticancer agents

Selective inhibition of histone deacetylases (HDACs) is an important strategy in the field of anticancer drug discovery. However, lack of inhibitors that possess high selectivity toward certain HDACs isozymes is associated with adverse side effects that limits their clinical applications. We have initiated a collaborative initiatives between multi-institutions aimed at the discovery of novel and selective HDACs inhibitors. To this end, a phenotypic screening of an in-house pilot library of about 70 small molecules against various HDAC isozymes led to the discovery of five compounds that displayed varying degrees of HDAC isozyme selectivity. The anticancer activities of these molecules were validated using various biological assays including transcriptomic studies. Compounds 15, 14, and 19 possessed selective inhibitory activity against HDAC5, while 28 displayed selective inhibition of HDAC1 and HDAC2. Compound 22 was found to be a selective inhibitor for HDAC3 and HDAC9. Importantly, we discovered a none-hydroxamate based HDAC inhibitor, compound 28, representing a distinct chemical probe of HDAC inhibitors. It contains a trifluoromethyloxadiazolyl moiety (TFMO) as a non-chelating metal-binding group. The new compounds showed potent anti-proliferative activity when tested against MCF7 breast cancer cell line, as well as increased acetylation of histones and induce cells apoptosis. The new compounds apoptotic effects were validated through the upregulation of proapoptotic proteins caspases3 and 7 and downregulation of the antiapoptotic biomarkers C-MYC, BCL2, BCL3 and NFĸB genes. Furthermore, the new compounds arrested cell cycle at different phases, which was confirmed through downregulation of the CDK1, 2, 4, 6, E2F1 and RB1 proteins. Taken together, our findings provide the foundation for the development of new chemical probes as potential lead drug candidates for the treatment of cancer

Elucidating the path to Plasmodium prolyl-tRNA synthetase inhibitors that overcome halofuginone resistance

© The Author(s) 2022 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.The development of next-generation antimalarials that are efficacious against the human liver and asexual blood stages is recognized as one of the world's most pressing public health challenges. In recent years, aminoacyl-tRNA synthetases, including prolyl-tRNA synthetase, have emerged as attractive targets for malaria chemotherapy. We describe the development of a single-step biochemical assay for Plasmodium and human prolyl-tRNA synthetases that overcomes critical limitations of existing technologies and enables quantitative inhibitor profiling with high sensitivity and flexibility. Supported by this assay platform and co-crystal structures of representative inhibitor-target complexes, we develop a set of high-affinity prolyl-tRNA synthetase inhibitors, including previously elusive aminoacyl-tRNA synthetase triple-site ligands that simultaneously engage all three substrate-binding pockets. Several compounds exhibit potent dual-stage activity against Plasmodium parasites and display good cellular host selectivity. Our data inform the inhibitor requirements to overcome existing resistance mechanisms and establish a path for rational development of prolyl-tRNA synthetase-targeted anti-malarial therapies.This work was supported by NIH R01AI143723 (R.M. and D.F.W.), NIH R01AI152533 (M.R.L. and E.A.W.), 5F31AI129412 (L.F.), and the Bill & Melinda Gates Foundation (OPP1054480, E.A.W. and D.F.W.), LEAN program of the Leducq Foundation (U.O.), Arthritis Research UK 20522 (U.O.), Cancer Research UK A23900 (U.O.). N.C.P. was supported by a National Science Foundation Graduate Research Fellowship (DGE1745303). M.R.L. was supported in part by a Ruth L. Kirschstein Institutional National Research Award from the National Institute for General Medical Sciences (T32 GM008666). This publication includes data generated at the University of California, San Diego IGM Genomics Center utilizing an Illumina NovaSeq 6000 that was purchased with funding from a National Institutes of Health SIG grant (#S10 OD026929).info:eu-repo/semantics/publishedVersio

Chemical genetic strategy identifies histone deacetylase 1 (HDAC1) and HDAC2 as therapeutic targets in sickle cell disease

The worldwide burden of sickle cell disease is enormous, with over 200,000 infants born with the disease each year in Africa alone. Induction of fetal hemoglobin is a validated strategy to improve symptoms and complications of this disease. The development of targeted therapies has been limited by the absence of discrete druggable targets. We developed a unique bead-based strategy for the identification of inducers of fetal hemoglobin transcripts in primary human erythroid cells. A small-molecule screen of bioactive compounds identified remarkable class-associated activity among histone deacetylase (HDAC) inhibitors. Using a chemical genetic strategy combining focused libraries of biased chemical probes and reverse genetics by RNA interference, we have identified HDAC1 and HDAC2 as molecular targets mediating fetal hemoglobin induction. Our findings suggest the potential of isoform-selective inhibitors of HDAC1 and HDAC2 for the treatment of sickle cell disease

Advances in Malaria Pharmacology and the online Guide to MALARIA PHARMACOLOGY: IUPHAR Review X

Antimalarial drug discovery has until recently been driven by high-throughput phenotypic cellular screening, allowing millions of compounds to be assayed and delivering clinical drug candidates. In this review, we will focus on target-based approaches, describing recent advances in our understanding of druggable targets in the malaria parasite. Targeting multiple stages of the Plasmodium lifecycle, rather than just the clinically symptomatic asexual blood stage, has become a requirement for new antimalarial medicines, and we link pharmacological data clearly to the parasite stages to which it applies. Finally, we highlight the IUPHAR/MMV Guide to MALARIA PHARMACOLOGY, a web resource developed for the malaria research community that provides open and optimized access to published data on malaria pharmacology

AI is a viable alternative to high throughput screening: a 318-target study

: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery

Suivi de l'activité du thymus lors d'une contamination chronique par de faibles doses de césium 137

CHATENAY M.-PARIS 11-BU Pharma. (920192101) / SudocSudocFranceF

Systématique moléculaire de la sous-tribu des Angraecinae (Vandeae, Orchidaceae) (perspectives taxonomiques et implications de la relation plante-pollinisateur dans l'évolution des formes florales réunionnaises)

La reconstruction phylogénétique des orchidées de la sous-tribu des Angraecinae a été réalisée à partir de séquences d'ADN chloroplastique. Nos résultats indiquent clairement l'inclusion de la sous-tribu des Aerangidinae au sein de celle des Angraecinae et la polyphylie du genre Angraecum. L'étude de la biologie reproductive a montré que la majorité des espèces réunionnaises illustre parfaitement le syndrome de pollinisation lépidoptèrophile. Toutefois, deux cas semblent spécifiques de la Réunion : (1) l'autofertilité des espèces à long éperon (> 8 cm) et (2) l'ornithophilie des espèces de la section Hadrangis, dont l'interaction avec les oiseaux passériformes de la famille des Zosteropidés est tout à fait nouvelle pour la famille des Orchidaceae, chez laquelle la pollinisation par les oiseaux reste rarePhylogenetic investigation of subtribe Angraecinae from plastid DNA sequences was used for inferring both taxonomic implications and evolution of plant-pollinator interactions. Angraecinae and the large genus Angraecum as currently circumscribed do not form clades. While most of species are expected to be pollinated by small moth, pollination biology studies conducted on endemic species from Reunion highlighted two original cases: (1) the autonomous self-pollination of long-spurred species and (2) bird pollination (Zosterops borbonicus, Zosteropidae) of species belonging to the genus Angraecum sect. Hadrangis. For the first time, a bird species from a family that is not adapted for nectar collection is reported as an orchid pollinatorSAINT DENIS/REUNION-Droit Lettre (974112101) / SudocSudocFranceReunionFRR