Publications by authors named "Robert Van Horn"

Article Synopsis
  • IL-13 is a key cytokine involved in the pathophysiology of atopic dermatitis (AD), and lebrikizumab, tralokinumab, and cendakimab are monoclonal antibodies designed to target this cytokine.
  • Studies showed that lebrikizumab has a higher affinity for IL-13 and is more effective in neutralizing its effects than the other two antibodies, based on various assays and imaging techniques.
  • Unlike tralokinumab and cendakimab, lebrikizumab allows for the internalization of the IL-13 complex into cells, suggesting a unique mechanism that may explain its increased clinical effectiveness in treating AD.
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The ERK pathway is critical in oncogenesis; aberrations in components of this pathway are common in approximately 30% of human cancers. ERK1/2 (ERK) regulates cell proliferation, differentiation, and survival and is the terminal node of the pathway. BRAF- and MEK-targeted therapies are effective in BRAF V600E/K metastatic melanoma and lung cancers; however, responses are short-lived due to emergence of resistance.

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Although Aurora A, B, and C kinases share high sequence similarity, especially within the kinase domain, they function distinctly in cell-cycle progression. Aurora A depletion primarily leads to mitotic spindle formation defects and consequently prometaphase arrest, whereas Aurora B/C inactivation primarily induces polyploidy from cytokinesis failure. Aurora B/C inactivation phenotypes are also epistatic to those of Aurora A, such that the concomitant inactivation of Aurora A and B, or all Aurora isoforms by nonisoform-selective Aurora inhibitors, demonstrates the Aurora B/C-dominant cytokinesis failure and polyploidy phenotypes.

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Loss-of-function mutations in the retinoblastoma gene are common in several treatment-refractory cancers such as small-cell lung cancer and triple-negative breast cancer. To identify drugs synthetic lethal with mutation ( ), we tested 36 cell-cycle inhibitors using a cancer cell panel profiling approach optimized to discern cytotoxic from cytostatic effects. Inhibitors of the Aurora kinases AURKA and AURKB showed the strongest association in this assay.

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The KRASG12C protein product is an attractive, yet challenging, target for small molecule inhibition. One option for therapeutic intervention is to design small molecule ligands capable of binding to and inactivating KRASG12C via formation of a covalent bond to the sulfhydryl group of cysteine 12. In order to better understand the cellular off-target interactions of , a covalent KRASG12C inhibitor, we have completed a series of complementary chemical proteomics experiments in H358 cells.

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Stromal cell-derived factor-1 (SDF-1) and its receptor CXCR4 play a critical role in mobilization and redistribution of immune cells and hematopoietic stem cells (HSCs). We evaluated effects of two CXCR4-targeting agents, peptide antagonist LY2510924 and monoclonal antibody LY2624587, on mobilizing HSCs and white blood cells (WBCs) in humans, monkeys, and mice. Biochemical analysis showed LY2510924 peptide blocked SDF-1/CXCR4 binding in all three species; LY2624587 antibody blocked binding in human and monkey, with minimal activity in mouse.

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To evaluate the antitumor efficacy of cetuximab in combination with LSN3074753, an analog of LY3009120 and pan-RAF inhibitor in 79 colorectal cancer patient-derived xenograft (PDX) models. Seventy-nine well-characterized colorectal cancer PDX models were employed to conduct a single mouse per treatment group ( = 1) trial. Consistent with clinical results, cetuximab was efficacious in wild-type and PDX models, with an overall response rate of 6.

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A key goal in the clinical development of a new molecular entity is to quickly identify whether it has the potential for drug-drug interactions. In particular, confirmation of in vitro data in the early stage of clinical development would facilitate the decision making and inform future clinical pharmacology study designs. Plasma 4β-hydroxycholesterol (4β-HC) is considered as an emerging endogenous biomarker for cytochrome P450 3A (CYP3A), one of the major drug metabolizing enzymes.

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Unlabelled: We have identified previously undiscovered BRAF in-frame deletions near the αC-helix region of the kinase domain in pancreatic, lung, ovarian, and thyroid cancers. These deletions are mutually exclusive with KRAS mutations and occur in 4.21% of KRAS wild-type pancreatic cancer.

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LY3009120 is a pan-RAF and RAF dimer inhibitor that inhibits all RAF isoforms and occupies both protomers in RAF dimers. Biochemical and cellular analyses revealed that LY3009120 inhibits ARAF, BRAF, and CRAF isoforms with similar affinity, while vemurafenib or dabrafenib have little or modest CRAF activity compared to their BRAF activities. LY3009120 induces BRAF-CRAF dimerization but inhibits the phosphorylation of downstream MEK and ERK, suggesting that it effectively inhibits the kinase activity of BRAF-CRAF heterodimers.

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Intervention of cancer cell mitosis by antitubulin drugs is among the most effective cancer chemotherapies. However, antitubulin drugs have dose-limiting side effects due to important functions of microtubules in resting normal cells and are often rendered ineffective by rapid emergence of resistance. Antimitotic agents with different mechanisms of action and improved safety profiles are needed as new treatment options.

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Replacing hydrogen with deuterium as a means of altering ADME properties of drug molecules has recently enjoyed a renaissance, such that at least two deuterated chemical entities are currently in clinical development. Although most research in this area aims to increase the metabolic stability, and hence half-life of the active species, experience has shown that prediction of the in vivo behaviour of deuterated molecules is difficult and depends on multiple factors including the complexity of the metabolic scheme, the enzymes involved and hence the mechanism of the rate-determining step in the biotransformation. In an effort to elucidate some of these factors we examined the metabolic behaviour of two molecules from the Sanofi portfolio in a range of in vitro and in vivo systems.

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B-RAF selective inhibitors, including vemurafenib, were recently developed as effective therapies for melanoma patients with B-RAF V600E mutation. However, most patients treated with vemurafenib eventually develop resistance largely due to reactivation of MAPK signaling. Inhibitors of MAPK signaling, including MEK1/2 inhibitor trametinib, failed to show significant clinical benefit in patients with acquired resistance to vemurafenib.

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Clopidogrel is an antiplatelet agent widely used in cardiovascular diseases and an inactive prodrug that needs to be converted to an active metabolite in two sequential metabolic steps. Several CYP450 isoforms involved in these two steps have been described, although the relative contribution in vivo of each enzyme is still under debate. CYP2C19 is considered to be the major contributor to active metabolite formation.

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LY573636-sodium (tasisulam) is a small molecule antitumor agent with a novel mechanism of action currently being investigated in a variety of human cancers. In vitro, tasisulam induced apoptosis via the intrinsic pathway, resulting in cytochrome c release and caspase-dependent cell death. Using high content cellular imaging and subpopulation analysis of a wide range of in vitro and in vivo cancer models, tasisulam increased the proportion of cells with 4N DNA content and phospho-histone H3 expression, leading to G(2)-M accumulation and subsequent apoptosis.

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In post-Sputnik America, when many policymakers and social scientists feared the Soviet Union had a technological advantage over the United States, assessing the relative importance of patents for inventive activity and examining whether scientific research constituted a public good were paramount concerns. The neoliberals of the University of Chicago and the planners of the Cowles Commission both spoke to these issues. This paper sheds light on their views on patents and public goods in the late 1950s and early 1960s by examining representatives of Cowles and Chicago, Kenneth Arrow and Ronald Coase, respectively.

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p38 mitogen-activated protein kinase (MAPK) is rapidly activated by stresses and is believed to play an important role in the stress response. While Chk1 is known to mediate G(2) DNA damage checkpoint control, p38 was also reported to have an essential function in this checkpoint control. Here, we have investigated further the roles of p38 and Chk1 in the G(2) DNA damage checkpoint in cancer cells.

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In mammalian cells entry into and progression through mitosis are regulated by multiple mitotic kinases. How mitotic kinases interact with each other and coordinately regulate mitosis remains to be fully understood. Here we employed a chemical biology approach using selective small molecule kinase inhibitors to dissect the relationship between Cdk1 and Aurora A kinases during G(2)/M transition.

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What Is Already Known About This Subject: * Numerous cocktails using concurrent administration of several cytochrome P450 (CYP) isoform-selective probe drugs have been reported to investigate drug-drug interactions in vivo. * This approach has several advantages: characterize the inhibitory or induction potential of compounds in development toward the CYP enzymes identified in vitro in an in vivo situation, assess several enzymes in the same trial, and have complete in vivo information about potential CYP-based drug interactions.

What This Study Adds: * This study describes a new cocktail containing five probe drugs that has never been published.

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Time-dependent inhibition (TDI) of cytochrome P450 (P450) enzymes caused by new molecular entities (NMEs) is of concern because such compounds can be responsible for clinically relevant drug-drug interactions (DDI). Although the biochemistry underlying mechanism-based inactivation (MBI) of P450 enzymes has been generally understood for several years, significant advances have been made only in the past few years regarding how in vitro time-dependent inhibition data can be used to understand and predict clinical DDI. In this article, a team of scientists from 16 pharmaceutical research organizations that are member companies of the Pharmaceutical Research and Manufacturers of America offer a discussion of the phenomenon of TDI with emphasis on the laboratory methods used in its measurement.

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The early 1980s constituted a watershed in science, mainly concerning the extent and nature of globalization and commercialization of scientific research, and its impact upon the university. Considerable debate has arisen about the sources of this transition, but aside from a few lone voices, the scholarly literature has neglected the concurrent rise of the contract research organization (CRO) and its role int he commercialization of scientific research. The CRO warrants wider attention as a modern paradigm of privatized science in the biopharmaceutical sector.

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Asthma is characterized by infiltration and shedding of the bronchial epithelium. The Th2 cytokines IL-4 and IL-13 are involved in the cellular recruitment and infiltration seen in asthma. The effects of IL-4 and IL-13 on cell-matrix interactions and epithelial shedding are unknown.

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Tumors such as ovarian, lung, and breast have been found to have a predilection for the pleura. Pleural mesothelial cells (PMCs) play an active role in pleural inflammation via release of cytokines. However, mechanisms whereby PMCs defend themselves against invading malignant cells are unknown.

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Study Objectives: Sialomucin complex (SMC) is a heterodimeric glycoprotein, and is found on the surfaces of the mesothelia of the pleura, pericardium, and peritoneum. Sialomucins play a significant role in adhesion as well as in defense. In this study, we hypothesized that pleural mesothelial cells (PMCs) express SMC and thus prevent the adherence of ovarian cancer cells (HTB-77) to the pleura.

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In bacterial empyema, the recruited polymorphonuclear leukocytes (PMN) represent important phagocytic cells involved in antibacterial defense. In this study we demonstrate that pleural fluids (PF) obtained from patients with empyema (EMP) contains significantly higher levels of granulocyte colony stimulating factor (GM-CSF), and PMN incubated in empyema (EMP) pleural fluid (PF) showed significantly less apoptosis than congestive heart failure (CHF) PF. Staphylococcus aureus-stimulated PMC released significantly (P < 0.

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