Pharmacologically induced proteolysis of histone deacetylase-6 attenuates influenza virus replication despite limited anti-tumor effects.

The protein deacetylase HDAC6 has been controversially linked to cancer cell proliferation and viral propagation. We analyzed whether a pharmacological depletion of HDAC6 with a recent proteolysis-targeting chimera (PROTAC) kills tumor cells. We show that low micromolar doses of the cereblon-based PROTAC TH170, but not its inactive analog TH170E, induce proteasomal degradation of HDAC6.

Toward target 2035: EUbOPEN - a public-private partnership to enable & unlock biology in the open.

Target 2035 is a global initiative that seeks to identify a pharmacological modulator of most human proteins by the year 2035. As part of an ongoing series of annual updates of this initiative, we summarise here the efforts of the EUbOPEN project whose objectives and results are making a strong contribution to the goals of Target 2035. EUbOPEN is a public-private partnership with four pillars of activity: (1) chemogenomic library collections, (2) chemical probe discovery and technology development for hit-to-lead chemistry, (3) profiling of bioactive compounds in patient-derived disease assays, and (4) collection, storage and dissemination of project-wide data and reagents.

Mechanistic model advancements for optimal calcium removal in water treatment: Integral operation improvements and reactor design strategies.

Drinking water softening has primarily prioritized public health, environmental benefits, social costs and enhanced client comfort. Annually, over 35 billion cubic meters of water is softened worldwide, often utilizing three main techniques: nanofiltration, ion exchange and seeded crystallization by pellet softening. However, recent modifications in pellet softening, including changes in seeding materials and acid conditioning used post-softening, have not fully achieved desired flexibility and optimization.

Selective degradation of mutant FMS-like tyrosine kinase-3 requires BIM-dependent depletion of heat shock proteins.

Internal tandem duplications in the FMS-like tyrosine kinase-3 (FLT3-ITD) are common mutations in acute myeloid leukemia (AML). Proteolysis-targeting chimeras (PROTACs) that induce proteasomal degradation of mutated FLT3 emerge as innovative pharmacological approach. Molecular mechanisms that control targeted proteolysis beyond the ubiquitin-proteasome-system are undefined and PROTACs are the only known type of FLT3 degraders.

Inhibitors of the tyrosine kinases FMS-like tyrosine kinase-3 and WEE1 induce apoptosis and DNA damage synergistically in acute myeloid leukemia cells.

Hyperactive FMS-like receptor tyrosine kinase-3 mutants with internal tandem duplications (FLT3-ITD) are frequent driver mutations of aggressive acute myeloid leukemia (AML). Inhibitors of FLT3 produce promising results in rationally designed cotreatment schemes. Since FLT3-ITD modulates DNA replication and DNA repair, valid anti-leukemia strategies could rely on a combined inhibition of FLT3-ITD and regulators of cell cycle progression and DNA integrity.

The protein phosphatase-2A subunit PR130 is involved in the formation of cytotoxic protein aggregates in pancreatic ductal adenocarcinoma cells.

As a major source of cellular serine and threonine phosphatase activity, protein phosphatase-2A (PP2A) modulates signaling pathways in health and disease. PP2A complexes consist of catalytic, scaffolding, and B-type subunits. Seventeen PP2A B-type subunits direct PP2A complexes to selected substrates.

Pharmacological degradation of ATR induces antiproliferative DNA replication stress in leukemic cells.

Mammalian cells replicate ~ 3 × 10 base pairs per cell cycle. One of the key molecules that slows down the cell cycle and prevents excessive DNA damage upon DNA replication stress is the checkpoint kinase ataxia-telangiectasia-and-RAD3-related (ATR). Proteolysis-targeting-chimeras (PROTACs) are an innovative pharmacological invention to molecularly dissect, biologically understand, and therapeutically assess catalytic and non-catalytic functions of enzymes.

Herbivore effects increase with latitude across the extent of a foundational seagrass.

Climate change is altering the functioning of foundational ecosystems. While the direct effects of warming are expected to influence individual species, the indirect effects of warming on species interactions remain poorly understood. In marine systems, as tropical herbivores undergo poleward range expansion, they may change food web structure and alter the functioning of key habitats.

Design, synthesis, and biological characterization of proteolysis targeting chimera (PROTACs) for the ataxia telangiectasia and RAD3-related (ATR) kinase.

The Ataxia telangiectasia and RAD3-related (ATR) kinase is a key regulator of DNA replication stress responses and DNA-damage checkpoints. Several potent and selective ATR inhibitors are reported and four of them are currently in clinical trials in combination with radio- or chemotherapy. Based on the idea of degrading target proteins rather than inhibiting them, we designed, synthesized and biologically characterized a library of ATR-targeted proteolysis targeting chimera (PROTACs).

Eosinophilic Fasciitis Possibly Provoked by Exercise.

A 26-year-old woman was referred to dermatology for evaluation of "lumpy skin" for 4 months. She experienced Achilles tendon pain and muscle tightness, occurring before the skin lesions had appeared. The lesions began on her arms and progressed to her legs over 1 month.

Medicinal chemistry advances in targeting class I histone deacetylases.

Histone deacetylases (HDACs) are a class of zinc (Zn)-dependent metalloenzymes that are responsible for epigenetic modifications. HDACs are largely associated with histone proteins that regulate gene expression at the DNA level. This tight regulation is controlled by acetylation [via histone acetyl transferases (HATs)] and deacetylation (via HDACs) of histone and non-histone proteins that alter the coiling state of DNA, thus impacting gene expression as a downstream effect.

NOXA Accentuates Apoptosis Induction by a Novel Histone Deacetylase Inhibitor.

Epigenetic modifiers of the histone deacetylase (HDAC) family are often dysregulated in cancer cells. Experiments with small molecule HDAC inhibitors (HDACi) have proven that HDACs are a vulnerability of transformed cells. We evaluated a novel hydroxamic acid-based HDACi (KH16; termed yanostat) in human pancreatic ductal adenocarcinoma (PDAC) cells, short- and long-term cultured colorectal cancer (CRC) cells, and retinal pigment epithelial cells.

Novel hydroxamic acid derivative induces apoptosis and constrains autophagy in leukemic cells.

Introduction: Posttranslational modification of proteins by reversible acetylation regulates key biological processes. Histone deacetylases (HDACs) catalyze protein deacetylation and are frequently dysregulated in tumors. This has spurred the development of HDAC inhibitors (HDACi).

Target 2035 - an update on private sector contributions.

Target 2035, an international federation of biomedical scientists from the public and private sectors, is leveraging 'open' principles to develop a pharmacological tool for every human protein. These tools are important reagents for scientists studying human health and disease and will facilitate the development of new medicines. It is therefore not surprising that pharmaceutical companies are joining Target 2035, contributing both knowledge and reagents to study novel proteins.

Pharmacological Modulation of the Crosstalk between Aberrant Janus Kinase Signaling and Epigenetic Modifiers of the Histone Deacetylase Family to Treat Cancer.

Hyperactivated Janus kinase (JAK) signaling is an appreciated drug target in human cancers. Numerous mutant JAK molecules as well as inherent and acquired drug resistance mechanisms limit the efficacy of JAK inhibitors (JAKi). There is accumulating evidence that epigenetic mechanisms control JAK-dependent signaling cascades.

AP1/Fra1 confers resistance to MAPK cascade inhibition in pancreatic cancer.

Targeting KRAS downstream signaling remains an important therapeutic approach in pancreatic cancer. We used primary pancreatic ductal epithelial cells and mouse models allowing the conditional expression of oncogenic Kras, to investigate KRAS signaling integrators. We observed that the AP1 family member FRA1 is tightly linked to the KRAS signal and expressed in pre-malignant lesions and the basal-like subtype of pancreatic cancer.

Fragment Optimization of Reversible Binding to the Switch II Pocket on KRAS Leads to a Potent, In Vivo Active KRAS Inhibitor.

Activating mutations in KRAS are the most frequent oncogenic alterations in cancer. The oncogenic hotspot position 12, located at the lip of the switch II pocket, offers a covalent attachment point for KRAS inhibitors. To date, KRAS inhibitors have been discovered by first covalently binding to the cysteine at position 12 and then optimizing pocket binding.

Cloning Strategy for HDAC1/HDAC2 Hybrid Protein Expression in Mammalian Cells.

Dynamic deacetylation of non-histone proteins by histone deacetylases (HDACs) is a key regulator of protein functions, interactions, and turnover. Among class I HDACs, human HDAC1 and HDAC2 share more than 80% global homology at the amino acid level. However, despite the high redundancy, there are examples for differential substrate specificities of HDAC1 and HDAC2.

Monitoring Changes in Intracellular Reactive Oxygen Species Levels in Response to Histone Deacetylase Inhibitors.

Reactive oxygen species (ROS) are induced by several chemotherapeutics. In this protocol, we describe a flow cytometry-based method for the analysis of the intracellular levels of ROS in vital leukemic cells in response to the histone deacetylase inhibitor vorinostat. This measurement of ROS using the cell-permeable dye CM-H2DCFDA indicates intracellular oxidative stress.

Assessing the Effect of Histone Deacetylase Inhibitors on DNA Double-Strand Break Repair by Nonhomologous End Joining.

This book chapter describes a plasmid-based reporter method, first described by Bennardo et al. (2008) that we use in our laboratory for determining the activity of the repair of DNA double-strand breaks by nonhomologous end joining. This method can be used to measure the impact of epigenetic modifiers of the histone deacetylase family on this DNA repair pathway by flow cytometry.

Human Platelet Lysate as Valid Cell Growth Additive to Assess Protein Acetylation.

Experiments with cell cultures are an alternative to animal experiments. One problem, however, is the ethically questionable use of fetal calf serum (FCS, which some authors refer to as fetal bovine serum, FBS). Furthermore, FCS is an undefined variable mixture and a possible source of contaminations.

Targeting the MYC interaction network in B-cell lymphoma via histone deacetylase 6 inhibition.

Overexpression of MYC is a genuine cancer driver in lymphomas and related to poor prognosis. However, therapeutic targeting of the transcription factor MYC remains challenging. Here, we show that inhibition of the histone deacetylase 6 (HDAC6) using the HDAC6 inhibitor Marbostat-100 (M-100) reduces oncogenic MYC levels and prevents lymphomagenesis in a mouse model of MYC-induced aggressive B-cell lymphoma.