A Small Molecule Antagonist of CX3CR1 (KAND567) Inhibited the Tumor Growth-Promoting Effect of Monocytes in Chronic Lymphocytic Leukemia (CLL).

Background/objectives: Nurse-like cells (NLCs) derived from monocytes in the tumor microenvironment support the growth of chronic lymphocytic leukemia (CLL) cells. Here, we investigated the effects of a CX3CR1 (fractalkine receptor) antagonist (KAND567) on autologous monocytes and their pro-survival effects on CLL cells in vitro.

Methods: Plasma concentration of CX3CL1 was determined by ELISA and CX3CR1 expression by flow cytometry.

A Small Molecule Targeting the Intracellular Tyrosine Kinase Domain of ROR1 (KAN0441571C) Induced Significant Apoptosis of Non-Small Cell Lung Cancer (NSCLC) Cells.

The ROR1 receptor tyrosine kinase is expressed in embryonic tissues but is absent in normal adult tissues. ROR1 is of importance in oncogenesis and is overexpressed in several cancers, such as NSCLC. In this study, we evaluated ROR1 expression in NSCLC patients (N = 287) and the cytotoxic effects of a small molecule ROR1 inhibitor (KAN0441571C) in NSCLC cell lines.

A ROR1 Small Molecule Inhibitor (KAN0441571C) Induced Significant Apoptosis of Mantle Cell Lymphoma (MCL) Cells.

The receptor tyrosine kinase orphan receptor 1 (ROR1) is absent in most normal adult tissues but overexpressed in various malignancies and is of importance for tumor cell survival, proliferation, and metastasis. In this study, we evaluated the apoptotic effects of a novel small molecule inhibitor of ROR1 (KAN0441571C) as well as venetoclax (BCL-2 inhibitor), bendamustine, idelalisib (PI3Kδ inhibitor), everolimus (mTOR inhibitor), and ibrutinib (BTK inhibitor) alone or in combination in human MCL primary cells and cell lines. ROR1 expression was evaluated by flow cytometry and Western blot (WB).

Species-selective targeting of pathogens revealed by the atypical structure and active site of Trypanosoma cruzi histone deacetylase DAC2.

Writing and erasing of posttranslational modifications are crucial to phenotypic plasticity and antigenic variation of eukaryotic pathogens. Targeting pathogens' modification machineries, thus, represents a valid approach to fighting parasitic diseases. However, identification of parasitic targets and the development of selective anti-parasitic drugs still represent major bottlenecks.

Targeting the Receptor Tyrosine Kinase ROR1 by Small Molecules.

Receptor tyrosine kinases (RTKs) are frequently dysregulated in malignancies and important for the malignant characteristics of tumor cells. RTKs are attractive structures for drug targeting of cancer. The RTK ROR1 is of significance during embryogenesis but downregulated in post-partum tissues.

Predicting ROR1/BCL2 combination targeted therapy of small cell carcinoma of the lung.

Small cell lung cancer (SCLC) remains a deadly form of cancer, with a 5-year survival rate of less than 10 percent, necessitating novel therapies. Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is an oncofetal protein that is emerging as a therapeutic target and is co-expressed with BCL2 in multiple tumor types due to microRNA coregulation. We hypothesize that ROR1-targeted therapy is effective in small cell lung cancer and synergizes with therapeutic BCL2 inhibition.

A ROR1 small molecule inhibitor (KAN0441571C) induced significant apoptosis of ibrutinib-resistant ROR1 CLL cells.

ROR1 - a receptor tyrosine kinase - is overexpressed in CLL. Ibrutinib, a Bruton's tyrosine kinase inhibitor, is clinically effective in CLL but patients may develop resistance. We evaluated the effect of an ROR1 inhibitor, KAN0441571C, in CLL cells from six patients obtained before and after developing resistance to ibrutinib.

ROR1 Is Expressed in Diffuse Large B-Cell Lymphoma (DLBCL) and a Small Molecule Inhibitor of ROR1 (KAN0441571C) Induced Apoptosis of Lymphoma Cells.

The receptor tyrosine kinase ROR1 is absent in most normal adult tissues, but overexpressed in several malignancies. In this study, we explored clinical and functional inhibitory aspects of ROR1 in diffuse large B-cell lymphoma (DLBCL). ROR1 expression in tumor cells was more often observed in primary refractory DLBCL, Richter's syndrome and transformed follicular lymphoma than in relapsed and non-relapsed DLBCL patients ( < 0.

Inhibition of Histone Demethylases LSD1 and UTX Regulates ERα Signaling in Breast Cancer.

In breast cancer, Lysine-specific demethylase-1 (LSD1) and other lysine demethylases (KDMs), such as Lysine-specific demethylase 6A also known as Ubiquitously transcribed tetratricopeptide repeat, X chromosome (UTX), are co-expressed and co-localize with estrogen receptors (ERs), suggesting the potential use of hybrid (epi)molecules to target histone methylation and therefore regulate/redirect hormone receptor signaling. Here, we report on the biological activity of a dual-KDM inhibitor (MC3324), obtained by coupling the chemical properties of tranylcypromine, a known LSD1 inhibitor, with the 2OG competitive moiety developed for JmjC inhibition. MC3324 displays unique features not exhibited by the single moieties and well-characterized mono-pharmacological inhibitors.

Identification of novel quinazoline derivatives as potent antiplasmodial agents.

Despite the recent reductions in the global burden of malaria, this disease remains a devastating cause of death in tropical and subtropical regions. As there is no broadly effective vaccine for malaria, prevention and treatment still rely on chemotherapy. Unfortunately, emerging resistance to the gold standard artemisinin combination therapies means that new drugs with novel modes of action are urgently needed.

Targeting PFKFB3 radiosensitizes cancer cells and suppresses homologous recombination.

The glycolytic PFKFB3 enzyme is widely overexpressed in cancer cells and an emerging anti-cancer target. Here, we identify PFKFB3 as a critical factor in homologous recombination (HR) repair of DNA double-strand breaks. PFKFB3 rapidly relocates into ionizing radiation (IR)-induced nuclear foci in an MRN-ATM-γH2AX-MDC1-dependent manner and co-localizes with DNA damage and HR repair proteins.

A receptor tyrosine kinase ROR1 inhibitor (KAN0439834) induced significant apoptosis of pancreatic cells which was enhanced by erlotinib and ibrutinib.

There is a great unmet medical need in pancreatic carcinoma (PC) for novel drugs with other mechanisms of action than existing. PC cells express the onco-fetal RTK ROR1, absent on most normal post-partem cells. ROR1 is involved in proliferation, survival, EMT and metastasis of tumor cells in various malignancies.

Schistosome sirtuins as drug targets.

The sirtuins form a superfamily of evolutionarily conserved NAD(+)-dependent protein N-ϵ-acyl-lysine (AcK) deacylases with roles in a variety of key cellular processes. Sirtuins have a broadly conserved overall structure with a catalytic site formed by a hydrophobic channel between the NAD(+)-binding Rossmann fold domain and a smaller Zn(2+)-binding domain. Schistosomes express five members of the sirtuin family and generic sirtuin inhibitors induce apoptosis and death in schistosome larvae, the disruption of adult worm pairs, inhibition of egg laying and damage to the male and female worm reproductive systems.

Fluorescence-based screening assays for the NAD⁺-dependent histone deacetylase smSirt2 from Schistosoma mansoni.

Sirtuins are NAD(+)-dependent histone deacetylases (HDACs) that cleave off acetyl but also other acyl groups from the ϵ-amino group of lysines in histones and other substrate proteins. Five sirtuin isoforms are encoded in the genome of the parasitic pathogen Schistosoma mansoni. During its life cycle, S.

A homogeneous HTRF assay for the identification of inhibitors of the TWEAK-Fn14 protein interaction.

The TWEAK-Fn14 pathway is upregulated in models of inflammation, autoimmune diseases, and cancer. Both TWEAK and Fn14 show increased expression also in the CNS in response to different stimuli, particularly astrocytes, microglia, and neurons, leading to activation of NF-κB and release of proinflammatory cytokines. Although neutralizing antibodies against these proteins have been shown to have therapeutic efficacy in animal models of inflammation, no small-molecule therapeutics are yet available.

Identification of Plasmodium falciparum spermidine synthase active site binders through structure-based virtual screening.

Seven novel binders, binding in the active site of Plasmodium falciparum spermidine synthase, were identified by structure-based virtual screening. The binding of these compounds was experimentally verified by NMR techniques. Spermidine synthase, an enzyme involved in the polyamine pathway, has been suggested as a target for treating malaria.

Mechanism of action of pyridazine analogues on protein tyrosine phosphatase 1B (PTP1B).

The inhibitory effect on PTP1B caused by the addition of pyridazine analogues has been investigated. Biophysical techniques, that is, mass spectrometry (MS), nuclear magnetic resonance (NMR), and isothermal titration calorimetry (ITC) were used for the characterization. Pyridazine analogues cause catalytic oxidation of the reducing agent, generating hydrogen peroxide that oxidizes the active site cysteine on the enzyme, leading to enzyme inactivation.

Site-selective labeling strategies for screening by NMR.

NMR based screening has become an important tool in the pharmaceutical industry. Methods that provide information on the location of small molecule binding sites on the surface of a drug target (e. g.

Structure-based screening as applied to human FABP4: a highly efficient alternative to HTS for hit generation.

The time-limiting step in HTS often is the development of an appropriate assay. In addition, hits from HTS fairly often turn out to be false positives and generally display unfavorable properties for further development. Here we describe an alternative process for hit generation, applied to the human adipocyte fatty acid binding protein FABP4.

Structure-based screening and design in drug discovery.

Structure-based screening represents an integrated approach for the identification and optimization of hits by the combined use of nuclear magnetic resonance (NMR) spectroscopy, homology modeling and X-ray crystallography. A general feature of the methodology is the introduction of structure-based methods (NMR, modeling and X-ray) early in the drug discovery process to optimize hits in terms of their affinities and specificities. This approach promises to deliver leads with improved physicochemical properties as compared with leads generated from a traditional HTS program.

Site-selective screening by NMR spectroscopy with labeled amino acid pairs.

A new method for site-selective screening by NMR is presented. The core of the new method is the dual amino acid sequence specific labeling technique. Amino acid X is labeled with (13)C and amino acid Y is labeled with (15)N.