Publications by authors named "Marian Raschke"

Mitogen-activated protein kinase kinase kinase kinase 1 (MAP4K1) is a serine/threonine kinase that acts as an immune checkpoint downstream of T-cell receptor stimulation. MAP4K1 activity is enhanced by prostaglandin E2 (PGE2) and transforming growth factor beta (TGFβ), immune modulators commonly present in the tumor microenvironment. Therefore, its pharmacological inhibition is an attractive immuno-oncology concept for inducing therapeutic T-cell responses in cancer patients.

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BAY1128688 is a selective inhibitor of AKR1C3, investigated recently in a trial that was prematurely terminated due to drug-induced liver injury. These unexpected observations prompted use of the quantitative systems toxicology model, DILIsym, to determine possible mechanisms of hepatotoxicity. Using mechanistic in vitro toxicity data as well as clinical exposure data, DILIsym predicted the potential for BAY1128688 to cause liver toxicity (elevations in serum alanine aminotransferase (ALT)) and elevations in serum bilirubin.

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Article Synopsis
  • The study focuses on the discovery and optimization of new soluble guanylate cyclase (sGC) stimulators, which have potential therapeutic benefits for various conditions.
  • Researchers utilized ultrahigh-throughput screening to identify a new class of sGC stimulators, improving key properties like potency and solubility during the optimization process.
  • The result is BAY 1165747 (BAY-747), a promising treatment for resistant hypertension, showing effective hemodynamic results lasting up to 24 hours in early clinical trials.
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Endocrine disruption by environmental chemicals continues to be a concern for human safety. The rat, a widely used model organism in toxicology, is very sensitive to chemical-induced thyroid perturbation, e.g.

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Thyroid hormones (THs) are crucial regulators of human metabolism and early development. During the safety assessment of plant protection products, the human relevance of chemically induced TH perturbations observed in test animals remains uncertain. European regulatory authorities request follow-up in vitro studies to elucidate human-relevant interferences on thyroid gland function or TH catabolism through hepatic enzyme induction.

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Inhibition of monopolar spindle 1 (MPS1) kinase represents a novel approach to cancer treatment: instead of arresting the cell cycle in tumor cells, cells are driven into mitosis irrespective of DNA damage and unattached/misattached chromosomes, resulting in aneuploidy and cell death. Starting points for our optimization efforts with the goal to identify MPS1 inhibitors were two HTS hits from the distinct chemical series "triazolopyridines" and "imidazopyrazines". The major initial issue of the triazolopyridine series was the moderate potency of the HTS hits.

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The in vitro micronucleus test according to OECD Test Guideline 487 (TG 487) is widely used to investigate the genotoxic potential of drugs. Besides the identification of in vitro genotoxicants, the assay can be complemented with kinetochore staining for the differentiation between clastogens and aneugens. This differentiation constitutes a major contribution to risk assessment as especially aneugens show a threshold response.

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Antibody therapies targeting the epithelial growth factor receptor (EGFR) are being increasingly applied in cancer therapy. However, increased tumour containment correlates proportionally with the severity of well-known adverse events in skin. The prediction of the latter is not currently possible in conventional in vitro systems and limited in existing laboratory animal models.

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The in vivo Pig-a gene mutation assay serves to evaluate the genotoxic potential of chemicals. In the rat blood-based assay, the lack of CD59 on the surface of erythrocytes is quantified via fluorophore-labeled antibodies in conjunction with flow cytometric analysis to determine the frequency of Pig-a mutant phenotype cells. The assay has achieved regulatory relevance as it is suggested as an in vivo follow-up test for Ames mutagens in the recent ICH M7 [25] step 4 document.

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Article Synopsis
  • Chemical-induced disruptions of the cellular microtubule network play a significant role in aneugenicity, and understanding their nonlinear dose-response relationships helps in assessing drug safety and risks.
  • There's a lack of standardized assays for evaluating tubulin-interacting chemicals in genotoxicity testing, necessitating the use of multiple assays to accurately classify aneugenic effects.
  • A new tripartite approach involving a cell-free biochemical assay alongside cell-based imaging and flow cytometry provides comprehensive insights into tubulin dynamics, yielding useful data for research and safety evaluations.
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The rodent Pig-a assay is an in vivo method for the detection of gene mutation, where lack of glycosylphosphatidylinositol-anchored proteins on the surface of circulating red blood cells (RBCs) serves as a reporter for Pig-a gene mutation. In the case of rats, the frequency of mutant phenotype RBCs is measured via fluorescent anti-CD59 antibodies and flow cytometry. The Pig-a assay meets the growing expectations for novel approaches in animal experimentation not only focusing on the scientific value of the assay but also on animal welfare aspects (3Rs principles), for example, amenable to integration into pivotal rodent 28-day general toxicology studies.

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Monopolar spindle 1 (Mps1) has been shown to function as the key kinase that activates the spindle assembly checkpoint (SAC) to secure proper distribution of chromosomes to daughter cells. Here, we report the structure and functional characterization of two novel selective Mps1 inhibitors, BAY 1161909 and BAY 1217389, derived from structurally distinct chemical classes. BAY 1161909 and BAY 1217389 inhibited Mps1 kinase activity with IC50 values below 10 nmol/L while showing an excellent selectivity profile.

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This work seeks to provide users with guidance on cell culture, treatment, processing and analytical conditions for achieving optimal performance of the in vitro micronucleus assay using the In Vitro MicroFlow(®) method. Experimental data are provided to support the advice described. The information provided covers specific topics or issues that are identified as critical to the methodology and thus is meant to work with instruction manuals, published papers and other references, and not as a replacement for these documents.

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Introduction: In the past years several new urinary nephrotoxicity biomarkers have been qualified for use in preclinical studies by the FDA and EMA. Subsequently, kits have been developed to measure these urinary biomarkers on multiplex platforms such as the electro-chemiluminescent based immunoassay from MesoScale Discovery (MSD) and the bead-based immunoassay using Luminex xMAP technology (LMX). The aim of the present study was to compare the two multiplex platforms with respect to the capability of their qualified urinary biomarker panels to measure an increase of these biomarkers relative to histopathological changes in an animal model of nephrotoxicity.

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The main goal of the present work was to better understand the molecular mechanisms underlying liver hypertrophy (LH), a recurrent finding observed following acute or repeated drug administration to animals, using transcriptomic technologies together with the results from conventional toxicology methods. Administration of 5 terminated proprietary drug candidates from participating companies involved in the EU Innomed PredTox Project or the reference hepatotoxicant troglitazone to rats for up to a 14-day duration induced LH as the main liver phenotypic toxicity outcome. The integrated analysis of transcriptomic liver expression data across studies turned out to be the most informative approach for the generation of mechanistic models of LH.

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Objective: Nephrogenic systemic fibrosis (NSF) is an acquired, idiopathic disorder. Most of the cases are observed in patients with end stage renal disease (ESRD). The objective of this nonclinical animal study was to test the hypothesis that gadolinium (Gd) deposits play a role in the induction of NSF lesions.

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The InnoMed PredTox consortium was formed to evaluate whether conventional preclinical safety assessment can be significantly enhanced by incorporation of molecular profiling ("omics") technologies. In short-term toxicological studies in rats, transcriptomics, proteomics and metabolomics data were collected and analyzed in relation to routine clinical chemistry and histopathology. Four of the sixteen hepato- and/or nephrotoxicants given to rats for 1, 3, or 14days at two dose levels induced similar histopathological effects.

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Objective: It has been suggested that elements from the lanthanoid (Ln) series may be well suited for use as absorbing elements in X-ray contrast agents (CA). Because gadolinium, an element of the lanthanoid series, has been identified as being possibly associated with nephrogenic systemic fibrosis (NSF), a rare but potentially severe disease, we sought to determine if other lanthanoids might possess a similar potential.

Materials And Methods: By computed tomography (CT), we compared the X-ray attenuation of all lanthanoids to that of iodine in vitro.

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Dietary isoflavones, such as genistein and daidzein, are metabolised by the human gut microflora. Case-control studies have disclosed a link between the formation of the daidzein metabolite equol and prostate cancer risk. We evaluated the effects of genistein, daidzein and five metabolites on two prostate cancer cell lines by determining DNA integrity and cell growth.

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It has been postulated that the R- and S-equol enantiomers have different biological properties given their different binding affinities for the estrogen receptor. S-(-)equol is produced via the bacterial conversion of the soy isoflavone daidzein in the gut. We have compared the biological effects of purified S-equol to that of racemic (R and S) equol on breast and prostate cancer cells of varying receptor status in vitro.

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Prostate cancer is one of the most frequent cancer types in Western societies and predominately occurs in the elderly male. The strong age-related increase of prostate cancer is associated with a progressive accumulation of oxidative DNA damage which is presumably supported by a decline of the cellular antioxidative defence during ageing. Risk of developing prostate cancer is much lower in many Asian countries where soy food is an integral part of diet.

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