Dual TTK/PLK1 inhibition has potent anticancer activity in TNBC as monotherapy and in combination.

Background: Threonine tyrosine kinase (TTK) and polo-like kinase 1 (PLK1) are common essential kinases that collaborate in activating the spindle assembly checkpoint (SAC) at the kinetochore, ensuring appropriate chromosome alignment and segregation prior to mitotic exit. Targeting of either TTK or PLK1 has been clinically evaluated in cancer patients; however, dual inhibitors have not yet been pursued. Here we present the and characterization of a first in class, dual TTK/PLK1 inhibitor (BAL0891).

Screening of predicted synergistic multi-target therapies in glioblastoma identifies new treatment strategies.

Background: IDH-wildtype glioblastoma (GBM) is a highly malignant primary brain tumor with a median survival of 15 months after standard of care, which highlights the need for improved therapy. Personalized combination therapy has shown to be successful in many other tumor types and could be beneficial for GBM patients.

Methods: We performed the largest drug combination screen to date in GBM, using a high-throughput effort where we selected 90 drug combinations for their activity onto 25 patient-derived GBM cultures.

Mapping Arginase Expression with F-Fluorinated Late-Generation Arginase Inhibitors Derived from Quaternary α-Amino Acids.

Arginase hydrolyzes L-arginine and influences levels of polyamines and nitric oxide. Arginase overexpression is associated with inflammation and tumorigenesis. Thus, radiolabeled arginase inhibitors may be suitable PET tracers for staging arginase-related pathophysiologies.

Targeting Indoleamine 2,3-Dioxygenase in Cancer Models Using the Novel Small Molecule Inhibitor NTRC 3883-0.

Indoleamine 2,3-dioxygenase (IDO1) is a key regulator of immune suppression by catalyzing the oxidation of L-tryptophan. IDO1 expression has been related to poor prognosis in several cancers and to resistance to checkpoint immunotherapies. We describe the characterization of a novel small molecule IDO1 inhibitor, NTRC 3883-0, in a panel of biochemical and cell-based assays, and various cancer models.

Pharmacological validation of TDO as a target for Parkinson's disease.

Parkinson's disease patients suffer from both motor and nonmotor impairments. There is currently no cure for Parkinson's disease, and the most commonly used treatment, levodopa, only functions as a temporary relief of motor symptoms. Inhibition of the expression of the L-tryptophan-catabolizing enzyme tryptophan 2,3-dioxygenase (TDO) has been shown to inhibit aging-related α-synuclein toxicity in Caenorhabditis elegans.

Chemotherapy sensitivity testing on ovarian cancer cells isolated from malignant ascites.

Background: In epithelial ovarian cancer (EOC), 15-20% of the tumors do not respond to first-line chemotherapy (paclitaxel with platinum-based therapy), and in recurrences this number increases. Our aim is to determine the feasibility of cell proliferation assays of tumor cells isolated from malignant ascites to predict chemotherapy sensitivity, and to correlate these results with clinical outcome.

Materials And Methods: Ascites was collected from twenty women with advanced EOC.

Structural insights into human Arginase-1 pH dependence and its inhibition by the small molecule inhibitor CB-1158.

Arginase-1 is a manganese-dependent metalloenzyme that catalyzes the hydrolysis of L-arginine into L-ornithine and urea. Arginase-1 is abundantly expressed by tumor-infiltrating myeloid cells that promote tumor immunosuppression, which is relieved by inhibition of Arginase-1. We have characterized the potencies of the Arginase-1 reference inhibitors (2)-2-amino-6-boronohexanoic acid (ABH) and -hydroxy-nor-L-arginine (nor-NOHA), and studied their pH-dependence and binding kinetics.

High-Throughput Fluorescence-Based Activity Assay for Arginase-1.

Arginase-1, which converts the amino acid L-arginine into L-ornithine and urea, is a promising new drug target for cancer immunotherapy, as it has a role in the regulation of T-cell immunity in the tumor microenvironment. To enable the discovery of small-molecule Arginase-1 inhibitors by high-throughput screening, we developed a novel homogeneous (mix-and-measure) fluorescence-based activity assay. The assay measures the conversion of L-arginine into L-ornithine by a decrease in fluorescent signal due to quenching of a fluorescent probe, Arginase Gold.

Combined Cellular and Biochemical Profiling to Identify Predictive Drug Response Biomarkers for Kinase Inhibitors Approved for Clinical Use between 2013 and 2017.

Kinase inhibitors form the largest class of precision medicine. From 2013 to 2017, 17 have been approved, with 8 different mechanisms. We present a comprehensive profiling study of all 17 inhibitors on a biochemical assay panel of 280 kinases and proliferation assays of 108 cancer cell lines.

TTK Inhibitors as a Targeted Therapy for (-catenin) Mutant Cancers.

The spindle assembly checkpoint kinase TTK (Mps1) is a key regulator of chromosome segregation and is the subject of novel targeted therapy approaches by small-molecule inhibitors. Although the first TTK inhibitors have entered phase I dose escalating studies in combination with taxane chemotherapy, a patient stratification strategy is still missing. With the aim to identify a genomic biomarker to predict the response of tumor cells to TTK inhibitor therapy, we profiled a set of preclinical and clinical TTK inhibitors from different chemical series on a panel of 66 genetically characterized cell lines derived from different tumors (Oncolines).

Target Residence Time-Guided Optimization on TTK Kinase Results in Inhibitors with Potent Anti-Proliferative Activity.

The protein kinase threonine tyrosine kinase (TTK; also known as Mps1) is a critical component of the spindle assembly checkpoint and a promising drug target for the treatment of aggressive cancers, such as triple negative breast cancer. While the first TTK inhibitors have entered clinical trials, little is known about how the inhibition of TTK with small-molecule compounds affects cellular activity. We studied the selective TTK inhibitor NTRC 0066-0, which was developed in our own laboratory, together with 11 TTK inhibitors developed by other companies, including Mps-BAY2b, BAY 1161909, BAY 1217389 (Bayer), TC-Mps1-12 (Shionogi), and MPI-0479605 (Myrexis).

Stable aneuploid tumors cells are more sensitive to TTK inhibition than chromosomally unstable cell lines.

Inhibition of the spindle assembly checkpoint kinase TTK causes chromosome mis-segregation and tumor cell death. However, high levels of TTK correlate with chromosomal instability (CIN), which can lead to aneuploidy. We show that treatment of tumor cells with the selective small molecule TTK inhibitor NTRC 0066-0 overrides the mitotic checkpoint, irrespective of cell line sensitivity.

Optimized Target Residence Time: Type I1/2 Inhibitors for p38α MAP Kinase with Improved Binding Kinetics through Direct Interaction with the R-Spine.

Skepinone-L was recently reported to be a p38α MAP kinase inhibitor with high potency and excellent selectivity in vitro and in vivo. However, this class of compounds still act as fully ATP-competitive Type I binders which, furthermore, suffer from short residence times at the enzyme. We herein describe a further development with the first Type I1/2 binders for p38α MAP kinase.

Compound Selectivity and Target Residence Time of Kinase Inhibitors Studied with Surface Plasmon Resonance.

Target residence time (τ) has been suggested to be a better predictor of the biological activity of kinase inhibitors than inhibitory potency (IC) in enzyme assays. Surface plasmon resonance binding assays for 46 human protein and lipid kinases were developed. The association and dissociation constants of 80 kinase inhibitor interactions were determined.

IL-7 Receptor Mutations and Steroid Resistance in Pediatric T cell Acute Lymphoblastic Leukemia: A Genome Sequencing Study.

Background: Pediatric acute lymphoblastic leukemia (ALL) is the most common childhood cancer and the leading cause of cancer-related mortality in children. T cell ALL (T-ALL) represents about 15% of pediatric ALL cases and is considered a high-risk disease. T-ALL is often associated with resistance to treatment, including steroids, which are currently the cornerstone for treating ALL; moreover, initial steroid response strongly predicts survival and cure.

Cell Panel Profiling Reveals Conserved Therapeutic Clusters and Differentiates the Mechanism of Action of Different PI3K/mTOR, Aurora Kinase and EZH2 Inhibitors.

Cancer cell line panels are important tools to characterize the in vitro activity of new investigational drugs. Here, we present the inhibition profiles of 122 anticancer agents in proliferation assays with 44 or 66 genetically characterized cancer cell lines from diverse tumor tissues (Oncolines). The library includes 29 cytotoxics, 68 kinase inhibitors, and 11 epigenetic modulators.

Selective Targeting of CTNBB1-, KRAS- or MYC-Driven Cell Growth by Combinations of Existing Drugs.

The aim of combination drug treatment in cancer therapy is to improve response rate and to decrease the probability of the development of drug resistance. Preferably, drug combinations are synergistic rather than additive, and, ideally, drug combinations work synergistically only in cancer cells and not in non-malignant cells. We have developed a workflow to identify such targeted synergies, and applied this approach to selectively inhibit the proliferation of cell lines with mutations in genes that are difficult to modulate with small molecules.

High-throughput fluorescence-based screening assays for tryptophan-catabolizing enzymes.

Indoleamine 2,3-dioxygenase (IDO1) and tryptophan 2,3-dioxygenase (TDO) are two structurally different enzymes that have a different tissue distribution and physiological roles, but both catalyze the conversion of tryptophan to N-formylkynurenine (NFK). IDO1 has been clinically validated as a small-molecule drug target for cancer, while preclinical studies indicate that TDO may be a target for cancer immunotherapy and neurodegenerative disease. We have developed a high-throughput screening assay for IDO1 and TDO based on a novel chemical probe, NFK Green, that reacts specifically with NFK to form a green fluorescent molecule with an excitation wavelength of 400 nm and an emission wavelength of 510 nm.

Comparison of the cancer gene targeting and biochemical selectivities of all targeted kinase inhibitors approved for clinical use.

The anti-proliferative activities of all twenty-five targeted kinase inhibitor drugs that are in clinical use were measured in two large assay panels: (1) a panel of proliferation assays of forty-four human cancer cell lines from diverse tumour tissue origins; and (2) a panel of more than 300 kinase enzyme activity assays. This study provides a head-on comparison of all kinase inhibitor drugs in use (status Nov. 2013), and for six of these drugs, the first kinome profiling data in the public domain.

Delaying aging and the aging-associated decline in protein homeostasis by inhibition of tryptophan degradation.

Toxicity of aggregation-prone proteins is thought to play an important role in aging and age-related neurological diseases like Parkinson and Alzheimer's diseases. Here, we identify tryptophan 2,3-dioxygenase (tdo-2), the first enzyme in the kynurenine pathway of tryptophan degradation, as a metabolic regulator of age-related α-synuclein toxicity in a Caenorhabditis elegans model. Depletion of tdo-2 also suppresses toxicity of other heterologous aggregation-prone proteins, including amyloid-β and polyglutamine proteins, and endogenous metastable proteins that are sensors of normal protein homeostasis.

A guide to picking the most selective kinase inhibitor tool compounds for pharmacological validation of drug targets.

To establish the druggability of a target, genetic validation needs to be supplemented with pharmacological validation. Pharmacological studies, especially in the kinase field, are hampered by the fact that many reference inhibitors are not fully selective for one target. Fortunately, the initial trickle of selective inhibitors released in the public domain has steadily swelled into a stream.

Synthetic heparin derivatives as new anticoagulant drugs.

The journey towards a detailed mechanistic understanding of the anticoagulant action of heparin has resulted in synthetic mimetics with improved pharmacodynamic profiles. Inspired by the ternary complex formation of heparin with antithrombin III and thrombin, the active pentasaccharide fondaparinux has been succeeded by several clinical candidates, such as SR123781, that have tailor-made factor Xa and thrombin inhibitory activities combined with less aspecific binding (e.g.

Non-steroidal steroid receptor modulators.

The last ten years much attention has been focused on the finding of non-steroidal ligands for steroidal nuclear receptors for reasons such as diminishing cross-reactivity to eliminate side effect profiles, changing physicochemical properties which might cause different tissue distribution profiles and altering binding modes which influence the binding of cofactors. Compounds with a selective functionality profile are referred to as selective nuclear receptor modulators (e.g.