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1.
Drug Metab Rev ; 49(1): 18-34, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27718639

RESUMO

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 4ß-hydroxycholesterol (4ß-HC) is considered as an emerging endogenous biomarker for cytochrome P450 3A (CYP3A), one of the major drug metabolizing enzymes. Although there are increasing reports of the use of 4ß-HC in academic- and industry-sponsored clinical studies, a thorough review, summary and consideration of the advantages and challenges of using 4ß-HC to evaluate changes in CYP3A activity has not been attempted. Herein, we review the biology of 4ß-HC, its response to treatment with CYP3A inducers, inhibitors and mixed inducer/inhibitors in healthy volunteers and patients, the association of 4ß-HC with other probes of CYP3A activity (e.g. midazolam, urinary cortisol ratios), and present predictive pharmacokinetic models. We provide recommendations for studying hepatic CYP3A activity in clinical pharmacology studies utilizing 4ß-HC at different stages of drug development.


Assuntos
Citocromo P-450 CYP3A/metabolismo , Hidrocortisona/urina , Hidroxicolesteróis/sangue , Midazolam/sangue , Biomarcadores/sangue , Biomarcadores/urina , Citocromo P-450 CYP3A/efeitos dos fármacos , Indutores do Citocromo P-450 CYP3A/farmacologia , Inibidores do Citocromo P-450 CYP3A/farmacologia , Descoberta de Drogas , Interações Medicamentosas , Humanos , Hidroxicolesteróis/farmacocinética , Fígado/efeitos dos fármacos , Fígado/metabolismo , Modelos Biológicos
2.
Bioorg Med Chem ; 23(13): 3831-42, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25900628

RESUMO

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. Although some key metabolic reactions of the acetylcholine release stimulator HP184 4 were slowed in vitro and in vivo when deuterium was present at the sites of metabolism, this did not translate to an increase in overall metabolic stability. By contrast, the tryptase inhibitor AVE5638 13 was much more metabolically stable in vitro in its deuterated form than when unlabelled. These results indicate that it could be of value to concentrate efforts in this area to molecules which are metabolised by a major pathway that involves enzymes of the amine oxidase family or other low-capacity enzyme families.


Assuntos
Agonistas Colinérgicos/sangue , Hepatócitos/metabolismo , Indóis/sangue , Piridinas/sangue , Inibidores da Tripsina/sangue , Animais , Biotransformação , Linhagem Celular , Agonistas Colinérgicos/farmacocinética , Deutério , Estabilidade de Medicamentos , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Humanos , Hidrogênio , Indóis/farmacocinética , Masculino , Monoaminoxidase/metabolismo , Piridinas/farmacocinética , Ratos , Ratos Sprague-Dawley , Inibidores da Tripsina/farmacocinética
3.
Dermatol Ther (Heidelb) ; 13(7): 1535-1547, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37310643

RESUMO

INTRODUCTION: IL-13 is the primary upregulated cytokine in atopic dermatitis (AD) skin and is the pathogenic mediator driving AD pathophysiology. Lebrikizumab, tralokinumab and cendakimab are therapeutic monoclonal antibodies (mAb) that target IL-13. METHODS: We undertook studies to compare in vitro binding affinities and cell-based functional activities of lebrikizumab, tralokinumab and cendakimab. RESULTS: Lebrikizumab bound IL-13 with higher affinity (as determined using surface plasma resonance) and slower off-rate. It was more potent in neutralizing IL-13-induced effects in STAT6 reporter and primary dermal fibroblast periostin secretion assays than either tralokinumab or cendakimab. Live imaging confocal microscopy was employed to determine the mAb effects on IL-13 internalization into cells via the decoy receptor IL-13Rα2, using A375 and HaCaT cells. The results showed that only the IL-13/lebrikizumab complex was internalized and co-localized with lysosomes, whereas IL-13/tralokinumab or IL-13/cendakimab complexes did not internalize. CONCLUSION: Lebrikizumab is a potent, neutralizing high-affinity antibody with a slow disassociation rate from IL-13. Additionally, lebrikizumab does not interfere with IL-13 clearance. Lebrikizumab has a different mode of action to both tralokinumab and cendakimab, possibly contributing to the clinical efficacy observed by lebrikizumab in Ph2b/3 AD studies.

4.
Drug Metab Dispos ; 40(1): 187-97, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22004687

RESUMO

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. In the current study, net CYP2C19 contribution to the active metabolite formation was determined from exposure of the active metabolite in two clinical studies (one phase I study with well balanced genetic polymorphic populations and a meta-analysis with a total of 396 healthy volunteers) at different clopidogrel doses. CYP2C19 involvements were estimated to be from 58 to 67% in intermediate metabolizers (IMs), from 58 to 72% in extensive metabolizers (EMs), and from 56 to 74% in ultrarapid metabolizers (UMs), depending on the study and the dose. For this purpose, a static model was proposed to estimate the net contribution of a given enzyme to the secondary metabolite formation. This static model was compared with a dynamic approach (Simcyp model) and showed good consistency. In parallel, in vitro investigations showed that omeprazole is a mechanism-based inhibitor of CYP2C19 with K(I) of 8.56 µM and K(inact) of 0.156 min(-1). These values were combined with the net CYP2C19 contribution to the active metabolite formation, through a static approach, to predict the inhibitory effect at 80-mg omeprazole doses in EM, IM, and UM CYP2C19 populations, with good consistency, compared with observed clinical values.


Assuntos
Hidrocarboneto de Aril Hidroxilases/genética , Omeprazol/farmacologia , Polimorfismo Genético/fisiologia , Ticlopidina/análogos & derivados , Adolescente , Adulto , Idoso , Hidrocarboneto de Aril Hidroxilases/fisiologia , Clopidogrel , Estudos Cross-Over , Citocromo P-450 CYP2C19 , Feminino , Humanos , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , Microssomos Hepáticos/metabolismo , Pessoa de Meia-Idade , Ticlopidina/metabolismo
5.
J Biol Chem ; 285(28): 21849-57, 2010 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-20444701

RESUMO

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. We find that activation of Aurora A first occurs at centrosomes at late G(2) and is required for centrosome separation independently of Cdk1 activity. Upon entry into mitosis, Aurora A then becomes fully activated downstream of Cdk1 activation. Inactivation of Aurora A or Plk1 individually during a synchronized cell cycle shows no significant effect on Cdk1 activation and entry into mitosis. However, simultaneous inactivation of both Aurora A and Plk1 markedly delays Cdk1 activation and entry into mitosis, suggesting that Aurora A and Plk1 have redundant functions in the feedback activation of Cdk1. Together, our data suggest that Cdk1, Aurora A, and Plk1 mitotic kinases participate in a feedback activation loop and that activation of Cdk1 initiates the feedback loop activity, leading to rapid and timely entry into mitosis in human cells. In addition, live cell imaging reveals that the nuclear cycle of cells becomes uncoupled from cytokinesis upon inactivation of both Aurora A and Aurora B kinases and continues to oscillate in a Cdk1-dependent manner in the absence of cytokinesis, resulting in multinucleated, polyploidy cells.


Assuntos
Proteína Quinase CDC2/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Aurora Quinase A , Aurora Quinase B , Aurora Quinases , Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Divisão Celular , Fase G2 , Células HeLa , Histonas/química , Humanos , Camundongos , Mitose , Fosforilação , Proteínas Proto-Oncogênicas/metabolismo , Treonina/química , Veias Umbilicais/citologia , Quinase 1 Polo-Like
6.
J Hist Behav Sci ; 47(3): 302-21, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21732377

RESUMO

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. Furthermore, it evaluates whether their views on patents and public goods clashed with the interests of RAND, at which both Arrow and Coase worked at some point during this time period. The paper argues that the Chicago-neoliberal position of Coase undermined the interests of RAND, while the Cowles-planning conclusions of Arrow furthered those interests.


Assuntos
Ciências do Comportamento/história , Economia/história , Modelos Econômicos , Patentes como Assunto/história , Política , História do Século XX , Humanos , Pesquisa , Socialismo , Tecnologia/economia , Tecnologia/história , Estados Unidos , Guerra
7.
Mol Cancer Ther ; 19(2): 325-336, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31744895

RESUMO

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. Reactivation of ERK signaling is central to the mechanisms of acquired resistance. Therefore, ERK inhibition provides an opportunity to overcome resistance and leads to improved efficacy. In addition, KRAS-mutant cancers remain an unmet medical need in which ERK inhibitors may provide treatment options alone or in combination with other agents. Here, we report identification and activity of LY3214996, a potent, selective, ATP-competitive ERK inhibitor. LY3214996 treatment inhibited the pharmacodynamic biomarker, phospho-p90RSK1, in cells and tumors, and correlated with LY3214996 exposures and antitumor activities. In in vitro cell proliferation assays, sensitivity to LY3214996 correlated with ERK pathway aberrations. LY3214996 showed dose-dependent tumor growth inhibition and regression in xenograft models harboring ERK pathway alterations. Importantly, more than 50% target inhibition for up to 8 to 16 hours was sufficient for significant tumor growth inhibition as single agent in BRAF- and KRAS-mutant models. LY3214996 also exhibited synergistic combination benefit with a pan-RAF inhibitor in a KRAS-mutant colorectal cancer xenograft model. Furthermore, LY3214996 demonstrated antitumor activity in BRAF-mutant models with acquired resistance in vitro and in vivo. Based on these preclinical data, LY3214996 has advanced to an ongoing phase I clinical trial (NCT02857270).


Assuntos
Neoplasias/tratamento farmacológico , Medicina de Precisão , Animais , Modelos Animais de Doenças , Feminino , Humanos , Camundongos , Camundongos Nus , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico
8.
Drug Metab Dispos ; 37(7): 1355-70, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19359406

RESUMO

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. Results of an anonymous survey regarding pharmaceutical industry practices and strategies around TDI are reported. Specific topics that still possess a high degree of uncertainty are raised, such as parameter estimates needed to make predictions of DDI magnitude from in vitro inactivation parameters. A description of follow-up mechanistic experiments that can be done to characterize TDI are described. A consensus recommendation regarding common practices to address TDI is included, the salient points of which include the use of a tiered approach wherein abbreviated assays are first used to determine whether NMEs demonstrate TDI or not, followed by more thorough inactivation studies for those that do to define the parameters needed for prediction of DDI.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Indústria Farmacêutica , Interações Medicamentosas , Microssomos Hepáticos/metabolismo , Hidrocarboneto de Aril Hidroxilases/metabolismo , Citocromo P-450 CYP2B6 , Citocromo P-450 CYP3A/metabolismo , Desenho de Fármacos , Glucuronosiltransferase , Humanos , Microssomos Hepáticos/enzimologia , Oxirredutases N-Desmetilantes/metabolismo , Preparações Farmacêuticas/metabolismo , Relação Estrutura-Atividade , Especificidade por Substrato , Fatores de Tempo
9.
Br J Clin Pharmacol ; 68(6): 928-35, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20002088

RESUMO

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. * This cocktail can be used to test the effects of a new chemical entity on multiple CYP isoforms in a single clinical study: CYP1A2 (caffeine), CYP2C9 (warfarin), CYP2C19 (omeprazole), CYP2D6 (metoprolol), and CYP3A (midazolam) and was designed to overcome potential liabilities of other reported cocktails. AIMS: To assess the pharmacokinetics (PK) of selective substrates of CYP1A2 (caffeine), CYP2C9 (S-warfarin), CYP2C19 (omeprazole), CYP2D6 (metoprolol) and CYP3A (midazolam) when administered orally and concurrently as a cocktail relative to the drugs administered alone. METHODS: This was an open-label, single-dose, randomized, six-treatment six-period six-sequence William's design study with a wash-out of 7 or 14 days. Thirty healthy male subjects received 100 mg caffeine, 100 mg metoprolol, 0.03 mg kg(-1) midazolam, 20 mg omeprazole and 10 mg warfarin individually and in combination (cocktail). Poor metabolizers of CYP2C9, 2C19 and 2D6 were excluded. Plasma samples were obtained up to 48 h for caffeine, metoprolol and omeprazole, 12 h for midazolam, 312 h for warfarin and the cocktail. Three different validated liquid chromatography tandem mass spectrometry methods were used. Noncompartmental PK parameters were calculated. Log-transformed C(max), AUC(last) and AUC for each analyte were analysed with a linear mixed effects model with fixed term for treatment, sequence and period, and random term for subject within sequence. Point estimates (90% CI) for treatment ratios (individual/cocktail) were computed for each analyte C(max), AUC(last) and AUC. RESULTS: There was no PK interaction between the probe drugs when administered in combination as a cocktail, relative to the probes administered alone, as the 90% CI of the PK parameters was within the prespecified bioequivalence limits of 0.80, 1.25. CONCLUSION: The lack of interaction between probes indicates that this cocktail could be used to evaluate the potential for multiple drug-drug interactions in vivo.


Assuntos
Cafeína/farmacocinética , Citocromo P-450 CYP1A2/farmacocinética , Midazolam/farmacocinética , Omeprazol/farmacocinética , Varfarina/administração & dosagem , Administração Oral , Adulto , Ansiolíticos/administração & dosagem , Ansiolíticos/farmacocinética , Antiulcerosos/administração & dosagem , Antiulcerosos/farmacocinética , Anticoagulantes/administração & dosagem , Anticoagulantes/farmacocinética , Área Sob a Curva , Cafeína/administração & dosagem , Estimulantes do Sistema Nervoso Central/administração & dosagem , Estimulantes do Sistema Nervoso Central/farmacocinética , Citocromo P-450 CYP1A2/administração & dosagem , Combinação de Medicamentos , Interações Medicamentosas , Quimioterapia Combinada , Humanos , Masculino , Taxa de Depuração Metabólica , Midazolam/administração & dosagem , Omeprazol/administração & dosagem , Adulto Jovem
10.
Mol Cancer Ther ; 18(12): 2207-2219, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31530649

RESUMO

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. Several Aurora inhibitors are in clinical trials for T/B-cell lymphoma, multiple myeloma, leukemia, lung, and breast cancers. Here, we describe an Aurora A-selective inhibitor, LY3295668, which potently inhibits Aurora autophosphorylation and its kinase activity in vitro and in vivo, persistently arrests cancer cells in mitosis, and induces more profound apoptosis than Aurora B or Aurora A/B dual inhibitors without Aurora B inhibition-associated cytokinesis failure and aneuploidy. LY3295668 inhibits the growth of a broad panel of cancer cell lines, including small-cell lung and breast cancer cells. It demonstrates significant efficacy in small-cell lung cancer xenograft and patient-derived tumor preclinical models as a single agent and in combination with standard-of-care agents. LY3295668, as a highly Aurora A-selective inhibitor, may represent a preferred approach to the current pan-Aurora inhibitors as a cancer therapeutic agent.


Assuntos
Antineoplásicos/uso terapêutico , Aurora Quinase A/antagonistas & inibidores , Mitose/efeitos dos fármacos , Antineoplásicos/farmacologia , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Células HeLa , Humanos , Masculino
11.
Cancer Discov ; 9(2): 248-263, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30373917

RESUMO

Loss-of-function mutations in the retinoblastoma gene RB1 are common in several treatment-refractory cancers such as small-cell lung cancer and triple-negative breast cancer. To identify drugs synthetic lethal with RB1 mutation (RB1 mut), 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 RB1 association in this assay. LY3295668, an AURKA inhibitor with over 1,000-fold selectivity versus AURKB, is distinguished by minimal toxicity to bone marrow cells at concentrations active against RB1 mut cancer cells and leads to durable regression of RB1 mut tumor xenografts at exposures that are well tolerated in rodents. Genetic suppression screens identified enforcers of the spindle-assembly checkpoint (SAC) as essential for LY3295668 cytotoxicity in RB1-deficient cancers and suggest a model in which a primed SAC creates a unique dependency on AURKA for mitotic exit and survival. SIGNIFICANCE: The identification of a synthetic lethal interaction between RB1 and AURKA inhibition, and the discovery of a drug that can be dosed continuously to achieve uninterrupted inhibition of AURKA kinase activity without myelosuppression, suggest a new approach for the treatment of RB1-deficient malignancies, including patients progressing on CDK4/6 inhibitors.See related commentary by Dick and Li, p. 169.This article is highlighted in the In This Issue feature, p. 151.


Assuntos
Aurora Quinase A/antagonistas & inibidores , Neoplasias da Mama/patologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Proteínas de Ligação a Retinoblastoma/metabolismo , Carcinoma de Pequenas Células do Pulmão/patologia , Ubiquitina-Proteína Ligases/metabolismo , Animais , Antineoplásicos/farmacologia , Apoptose , Aurora Quinase A/genética , Aurora Quinase A/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Proliferação de Células , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Nus , Proteínas de Ligação a Retinoblastoma/genética , Transdução de Sinais , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Carcinoma de Pequenas Células do Pulmão/metabolismo , Células Tumorais Cultivadas , Ubiquitina-Proteína Ligases/genética , Ensaios Antitumorais Modelo de Xenoenxerto
12.
ACS Med Chem Lett ; 9(6): 557-562, 2018 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-29937982

RESUMO

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 Compound 1, a covalent KRASG12C inhibitor, we have completed a series of complementary chemical proteomics experiments in H358 cells. A new thiol reactive probe (TRP) was designed and used to construct a cellular target occupancy assay for KRASG12C. In addition, the thiol reactive probes allowed us to profile potential off-target interactions of Compound 1 with over 3200 cysteine residues. In order to complement the TRP data we designed Compound 2, an alkyne containing version of Compound 1, to serve as bait in competitive chemical proteomics experiments. Herein, we describe and compare data from both the TRP and the click chemistry probe pull down experiments.

13.
Oncotarget ; 8(55): 94619-94634, 2017 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-29212254

RESUMO

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. Cellular analysis showed LY2624587 antibody, but not LY2510924 peptide, down-regulated cell surface CXCR4 and induced hematological tumor cell death; both agents have been shown to inhibit SDF-1/CXCR4 interaction and downstream signaling. In animal models, LY2510924 peptide induced robust, prolonged, dose- and time-dependent WBC and HSC increases in mice and monkeys, whereas LY2624587 antibody induced only moderate, transient increases in monkeys. In clinical trials, similar pharmacodynamic effects were observed in patients with advanced cancer: LY2510924 peptide induced sustained WBC and HSC increases, while LY2624587 antibody induced only minimal, transient WBC changes. These distinct pharmacodynamic effects in two different classes of CXCR4 inhibitors are clinically important and should be carefully considered when designing combination studies with immune checkpoint inhibitors or other agents for cancer therapy.

14.
Clin Cancer Res ; 23(18): 5547-5560, 2017 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-28611205

RESUMO

Purpose: 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.Experimental Design: Seventy-nine well-characterized colorectal cancer PDX models were employed to conduct a single mouse per treatment group (n = 1) trial.Results: Consistent with clinical results, cetuximab was efficacious in wild-type KRAS and BRAF PDX models, with an overall response rate of 6.3% and disease control rate (DCR) of 20.3%. LSN3074753 was active in a small subset of PDX models that harbored KRAS or BRAF mutations. However, the combination treatment displayed the enhanced antitumor activity with DCR of 35.4%. Statistical analysis revealed that BRAF and KRAS mutations were the best predictors of the combinatorial activity and were significantly associated with synergistic effect with a P value of 0.01 compared with cetuximab alone. In 12 models with BRAF mutations, the combination therapy resulted in a DCR of 41.7%, whereas either monotherapy had a DCR of 8.3%. Among 44 KRAS mutation models, cetuximab or LSN3074753 monotherapy resulted in a DCR of 13.6% or 11.4%, respectively, and the combination therapy increased DCR to 34.1%. Molecular analysis suggests that EGFR activation is a potential feedback and resistant mechanism of pan-RAF inhibition.Conclusions: MAPK and EGFR pathway activations are two major molecular hallmarks of colorectal cancer. This mouse PDX trial recapitulated clinical results of cetuximab. Concurrent EGFR and RAF inhibition demonstrated synergistic antitumor activity for colorectal cancer PDX models with a KRAS or BRAF mutation. Clin Cancer Res; 23(18); 5547-60. ©2017 AACR.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Colorretais/genética , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Mutação , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/genética , Animais , Biomarcadores Tumorais , Linhagem Celular Tumoral , Cetuximab/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Modelos Animais de Doenças , Quimioterapia Combinada , Receptores ErbB/metabolismo , Humanos , Ligantes , Camundongos , Compostos de Fenilureia/farmacologia , Polimorfismo de Nucleotídeo Único , Proteínas Proto-Oncogênicas B-raf/metabolismo , Pirimidinas/farmacologia , Taxa de Sobrevida , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Cancer Discov ; 6(3): 300-15, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26732095

RESUMO

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. siRNA knockdown in cells harboring BRAF deletions showed that the MAPK activity and cell growth are BRAF dependent. Structurally, the BRAF deletions are predicted to shorten the ß3/αC-helix loop and hinder its flexibility by locking the helix in the active αC-helix-in conformation that favors dimer formation. Expression of L485-P490-deleted BRAF is able to transform NIH/3T3 cells in a BRAF dimer-dependent manner. BRAF homodimer is confirmed to be the dominant RAF dimer by proximity ligation assays in BRAF deletion cells, which are resistant to the BRAF inhibitor vemurafenib and sensitive to LY3009120, a RAF dimer inhibitor. In tumor models with BRAF deletions, LY3009120 has shown tumor growth regression, whereas vemurafenib is inactive. SIGNIFICANCE: This study discovered oncogenic BRAF deletions with a distinct activation mechanism dependent on the BRAF dimer formation in tumor cells. LY3009120 is active against these cells and represents a potential treatment option for patients with cancer with these BRAF deletions, or other atypical BRAF mutations where BRAF functions as a dimer.


Assuntos
Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Deleção de Genes , Compostos de Fenilureia/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Multimerização Proteica , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/genética , Pirimidinas/farmacologia , Animais , Antineoplásicos/química , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Modelos Animais de Doenças , Expressão Ectópica do Gene , Expressão Gênica , Humanos , Sistema de Sinalização das MAP Quinases , Camundongos , Modelos Moleculares , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas/genética , Inibidores de Proteínas Quinases/química , Proteínas Proto-Oncogênicas B-raf/química , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Soc Stud Sci ; 35(4): 503-48, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16304738

RESUMO

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. In discussing the CRO's technologies, the purposes they pursue, and the legal and policy initiatives that have fostered their rapid rise, we confront the wider implications of the modern regime of commercialized science for the future conduct of scientific research. We identify five areas of innovation: treatment of human subjects, control of disclosure, subjection of research tools to commercialization, redefinition of authorship, and re-engineering the goals of research.


Assuntos
Pesquisa Biomédica , Serviços Contratados , Indústria Farmacêutica , Pesquisa Biomédica/tendências , Comércio , Indústria Farmacêutica/tendências , Humanos , Estados Unidos
17.
Mol Cancer Ther ; 14(11): 2463-72, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26304237

RESUMO

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. Mitosis-specific kinesin Eg5 represents an attractive anticancer target for discovering such new antimitotic agents, because Eg5 is essential only in mitotic progression and has no roles in resting, nondividing cells. Here, we show that a novel selective Eg5 inhibitor, LY2523355, has broad target-mediated anticancer activity in vitro and in vivo. LY2523355 arrests cancer cells at mitosis and causes rapid cell death that requires sustained spindle-assembly checkpoint (SAC) activation with a required threshold concentration. In vivo efficacy of LY2523355 is highly dose/schedule-dependent, achieving complete remission in a number of xenograft tumor models, including patient-derived xenograft (PDX) tumor models. We further establish that histone-H3 phosphorylation of tumor and proliferating skin cells is a promising pharmacodynamic biomarker for in vivo anticancer activity of LY2523355.


Assuntos
Apoptose/efeitos dos fármacos , Cinesinas/antagonistas & inibidores , Mitose/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Sulfonamidas/farmacologia , Tiadiazóis/farmacologia , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Células HCT116 , Células HT29 , Células HeLa , Humanos , Immunoblotting , Cinesinas/metabolismo , Camundongos Nus , Neoplasias/metabolismo , Neoplasias/patologia , Fatores de Tempo , Resultado do Tratamento , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Cancer Cell ; 28(3): 384-98, 2015 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-26343583

RESUMO

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. Further analyses demonstrated that LY3009120 also inhibits various forms of RAF dimers including BRAF or CRAF homodimers. Due to these unique properties, LY3009120 demonstrates minimal paradoxical activation, inhibits MEK1/2 phosphorylation, and exhibits anti-tumor activities across multiple models carrying KRAS, NRAS, or BRAF mutation.


Assuntos
Antineoplásicos/farmacologia , Neoplasias/tratamento farmacológico , Compostos de Fenilureia/farmacologia , Isoformas de Proteínas/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/genética , Pirimidinas/farmacologia , Proteínas ras/genética , Linhagem Celular Tumoral , Dimerização , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Mutação/efeitos dos fármacos , Mutação/genética , Neoplasias/genética , Fosforilação/efeitos dos fármacos , Fosforilação/genética , Isoformas de Proteínas/genética , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-raf/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
19.
Clin Pharmacokinet ; 41 Suppl 2: 19-26, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12383041

RESUMO

OBJECTIVE: To investigate the in vitro metabolism of the antithrombotic agent fondaparinux sodium in mammalian liver fractions and to evaluate its potential inhibitory effect on human cytochrome P450 (CYP)-mediated metabolism of other drugs. METHODS: Metabolism was evaluated by incubating radioisotope-labelled fondaparinux sodium with postmitochondrial liver fractions of rat, rabbit, monkey or human origin (three subjects). Human liver microsomal preparations and an NADPH-generating system were incubated with phenacetin, coumarin, tolbutamide, S-mephenytoin, bufuralol, chlorzoxazone or nifedipine. These are selectively metabolised by CYP isoforms: CYP1A2, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1 or CYP3A4, respectively. Experiments were designed to determine apparent K(i) (inhibitory constant) values for fondaparinux sodium against each CYP isoform, by varying concentrations of fondaparinux sodium and the selective substrate. Each experiment included control reaction mixtures containing an isoform-selective inhibitor. After incubation, the mixtures were analysed by LC-MS/MS or with fluorometric detection. RESULTS: All liver fractions were enzymatically active, as demonstrated by degradation of [(14)C]testosterone. No metabolism of fondaparinux sodium was detectable in postmitochondrial liver fractions. Apparent K(i) values for fondaparinux sodium against the CYP isoforms could not be determined because the oxidative metabolism of the isoform-selective CYP substrates was not significantly inhibited in pooled microsomal reaction mixtures. In the presence of selective CYP inhibitors, metabolism of each substrate was significantly reduced, confirming that inhibition could be observed in these assays. CONCLUSION: The demonstrated lack of mammalian hepatic metabolism of fondaparinux sodium is consistent with animal and human studies. The absence of inhibition of the human CYP isoforms commonly involved in the metabolism of drugs suggests that clinical treatment with fondaparinux sodium is unlikely to interfere with the pharmacokinetics and metabolism of a wide range of other drugs which are associated with CYP inhibition.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Fibrinolíticos/metabolismo , Microssomos Hepáticos/metabolismo , Polissacarídeos/metabolismo , Adulto , Animais , Cromatografia Líquida de Alta Pressão , Inibidores das Enzimas do Citocromo P-450 , Interações Medicamentosas , Feminino , Fibrinolíticos/farmacologia , Fondaparinux , Haplorrinos , Humanos , Técnicas In Vitro , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Masculino , Polissacarídeos/farmacologia , Coelhos , Ratos
20.
Chest ; 124(2): 682-7, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12907560

RESUMO

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. METHODS: PMCs were plated, and the adherence of HTB-77 cells was observed using a cytofluor. The PMC monolayer was pretreated with sialidase, and HTB-77 adherence was observed using cytofluor. In another set of HTB-77 cells, adherence was observed when the PMC monolayer was pretreated with supernatants of HTB-77 cells. Last, supernatants of HTB-77 cells were assayed for sialidase activity. RESULTS: The removal of SMC by sialidase greatly increased the adherence of HTB-77 cells to the PMC monolayer, which was statistically significant (p < 0.05). Similar results were obtained when the PMC monolayer was pretreated with the supernatants of HTB-77 cells. Supernatants of HTB-77 cells showed the presence of sialidase. CONCLUSIONS: The presence of SMC on the PMC acts as a defense layer, and its removal by sialidase increases the susceptibility of the PMC layer to the adherence of malignant cells and to increased metastasis. HTB-77 cells also express sialidase, which by its action on the monolayer aids in the adherence of tumor cells to the pleural surface.


Assuntos
Mucinas/fisiologia , Metástase Neoplásica/prevenção & controle , Neoplasias Ovarianas/metabolismo , Pleura/fisiologia , Adesão Celular/fisiologia , Feminino , Humanos , Neuraminidase/metabolismo , Neoplasias Ovarianas/enzimologia , Sialomucinas , Células Tumorais Cultivadas
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