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1.
Therapie ; 79(1): 13-22, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38065821

RESUMO

Therapeutic strategies are shifting from a "one-size-fits-all" population-based approach to a stratified approach targeting groups with similar characteristics, or even individuals, tailoring treatments to the unique characteristics of each patient. Since such strategies rely on increasingly complex knowledge and healthcare technologies, along with an understanding of the tools of precision medicine, the appropriate dissemination and use of these strategies involves a number of challenges for the medical community. Having evaluation methodologies that have been jointly designed with the institutional, industrial, academic stakeholders, and also patients, like streamlining the processes and externally validating performances, could enhance the relevance of the "evaluation" aspect of precision medicine. Creating a network of expert precision-medicine centers and ensuring that precision-medicine procedures are reimbursed by social security would guarantee fair and sustainable access. Finally, training healthcare professionals, creating interfaces between precision-medicine expert centers and primary care professionals as well as patients, and integrating individual patient data into medical records are all key drivers that will enable information from precision-medicine to be made available and guarantee the proper use of these approaches.


Assuntos
Atenção à Saúde , Medicina de Precisão , Humanos , Pacientes
3.
Therapie ; 78(1): 29-38, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36529559

RESUMO

For the past few years, platform trials have experienced a significant increase, recently amplified by the COVID-19 pandemic. The implementation of a platform trial is particularly useful in certain pathologies, particularly when there is a significant number of drug candidates to be assessed, a rapid evolution of the standard of care or in situations of urgent need for evaluation, during which the pooling of protocols and infrastructure optimizes the number of patients to be enrolled, the costs, and the deadlines for carrying out the investigation. However, the specificity of platform trials raises methodological, ethical, and regulatory issues, which have been the subject of the round table and which are presented in this article. The round table was also an opportunity to discuss the complexity of sponsorship and data management related to the multiplicity of partners, funding, and governance of these trials, and the level of acceptability of their findings by the competent authorities.


Assuntos
Ensaios Clínicos Adaptados como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Humanos , COVID-19 , Pandemias , SARS-CoV-2
5.
Therapie ; 76(6): 549-557, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34053732

RESUMO

AIMS: The French pharmaceutical companies' association (LEEM) biennially carries out a study on the attractiveness of France in pharmaceutical clinical research. This study aims to measure France's global competitiveness for international clinical trials (CT) and assess its strengths and areas of excellence. METHODS: A descriptive and comparative analysis was conducted using the data from both the ClinicalTrials.gov registry for the 2015-2019 period and those reported in a national web-based database (OSCAR) involving the major pharmaceutical companies operating in France in 2018-2019. OSCAR allows to describe the administrative authorization and starting process for all drug trials conducted in France. RESULTS: Among 8607 worldwide drug trials initiated in 2019, 34.3% (n=2.954) were funded exclusively by pharmaceutical companies (52.1% in France). On average, France was involved in 10.5% of all global industrial CTs launched over 2018-2019, still ranking in the 4th position among European countries. Early-phase trials represented 17.3% of trials conducted by the drug companies in France, versus 25% in Germany and 29% in United Kingdom. Oncology remains an area of excellence in France with 18.7% of all worldwide CTs conducted in this therapeutic area over the study period involving at least some French centres, ranking France 2nd among European countries. The median of total deadline before the first patient inclusion of 204 days in 2018-2019 with no marked improvement as compared to 2016-2017 period. However, the delay getting initial trial authorization was slightly reduced and an overall deadline of 167 days was observed for CTs entered the pilot phase initiated recently by the European regulation. CONCLUSION: After ten difficult years, areas of excellence, such as oncology and rare diseases and more recently, the outstanding mobilization for the COVID-19 research, have enabled France to maintain its pharmaceutical research. Furthermore, a set of additional decisions would strengthen this position in the next years.


Assuntos
COVID-19 , Pesquisa Farmacêutica , Indústria Farmacêutica , França , Humanos , SARS-CoV-2
6.
Therapie ; 73(5): 367-376, 2018 Oct.
Artigo em Francês | MEDLINE | ID: mdl-29753391

RESUMO

The Leem (French association of pharmaceutical companies) has conducted the eighth survey on attractiveness of France for clinical research. It serves to measure France's global competitiveness for international clinical trials and assess its strengths and areas of excellence. It also highlights the potential for progress and emerging trends at a time when the regulatory environment in France and Europe is undergoing change. This survey has been updated every two years since 2002 using the same methodology. It assesses the current status of research undertaken in France by the pharmaceutical industry between January 1st 2014 and December 31st 2015. Thirty companies (62% of the French market) have participated in this 8th survey which involved 3474 centers (versus 2860 in 2014) and 16,622 patients (versus 14,634 in 2014) enrolled in France across 586 clinical trials (versus 613 in 2014). This survey shows a reduction in the number of phase I and phase II trials. It also confirms that the studies conducted in France are primarily concerned with oncology (45%). Despite improvements across hospital contracts times (due to the adoption of the sole agreement) and performance indicators in trials (such as the number of patients enrolled by center), trial setup times in France are still overly lengthy (with stable times by French authorities). Ensuring that clinical research remains a priority issue for country is crucial for patients because of rapid access to innovation but also for the vitality of the French economy. Constructive dialogue with stakeholders on the subject of clinical research is essential to enhance the attractiveness of France and to improve the continuum between research, innovation and care.


Assuntos
Pesquisa Biomédica , Indústria Farmacêutica , Farmacologia Clínica , Ensaios Clínicos como Assunto , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , França , Humanos , Inquéritos e Questionários
7.
J Pathol ; 240(4): 461-471, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27577973

RESUMO

Dynamic control of endothelial cell junctions is essential for vascular homeostasis and angiogenesis. We recently provided genetic evidence that ANGPTL4 is a key regulator of vascular integrity both during developmental and in hypoxia-induced pathological conditions. The purpose of the present study was to decipher the molecular mechanisms through which ANGPTL4 regulates vascular integrity. Using surface plasmon resonance and proximity ligation assays, we show that ANGPTL4 binds integrin αvß3. In vitro and in vivo functional assays with Angptl4-deficient mice demonstrate that ANGPTL4-αvß3 interaction is necessary to mediate ANGPTL4 vasoprotective effects. Mechanistically, ANGPTL4-αvß3 interaction enhances Src recruitment to integrin αvß3 and inhibits Src signalling downstream of vascular endothelial growth factor receptor 2 (VEFGR2), thereby repressing hypoxia-induced breakdown of VEGFR2-VE-cadherin and VEGFR2-αvß3 complexes. We further demonstrate that intravitreal injection of recombinant human ANGPTL4 limits vascular permeability and leads to increased adherens junction and tight junction integrity. These findings identify a novel mechanism by which ANGPTL4 counteracts hypoxia-driven vascular permeability through integrin αvß3 binding, modulation of VEGFR2-Src kinase signalling, and endothelial junction stabilization. We further demonstrate that Angptl4-deficient mice show increased vascular leakage in vivo in a model of laser-induced choroidal neovascularization, indicating that this newly identified ANGPTL4-αvß3 axis might be a target for pharmaceutical intervention in pathological conditions. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Assuntos
Angiopoietinas/metabolismo , Permeabilidade Capilar/fisiologia , Integrina alfaVbeta3/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Proteína 4 Semelhante a Angiopoietina , Angiopoietinas/deficiência , Animais , Hipóxia Celular/fisiologia , Neovascularização de Coroide/metabolismo , Neovascularização de Coroide/fisiopatologia , Humanos , Camundongos Knockout , Fosforilação/fisiologia , Retina/metabolismo , Transdução de Sinais/fisiologia , Quinases da Família src/metabolismo
8.
FASEB J ; 28(8): 3351-61, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24760754

RESUMO

The protein tyrosine phosphatase 1B (PTP1B) modulates tyrosine kinase receptors, among which is the vascular endothelial growth factor receptor type 2 (VEGFR2), a key component of angiogenesis. Because PTP1B deficiency in mice improves left ventricular (LV) function 2 mo after myocardial infarction (MI), we hypothesized that enhanced angiogenesis early after MI via activated VEGFR2 contributes to this improvement. At 3 d after MI, capillary density was increased at the infarct border of PTP1B(-/-) mice [+7±2% vs. wild-type (WT), P = 0.05]. This was associated with increased extracellular signal-regulated kinase 2 phosphorylation and VEGFR2 activation (i.e., phosphorylated-Src/Src/VEGFR2 and dissociation of endothelial VEGFR2/VE-cadherin), together with higher infiltration of proangiogenic M2 macrophages within unchanged overall infiltration. In vitro, we showed that PTP1B inhibition or silencing using RNA interference increased VEGF-induced migration and proliferation of mouse heart microvascular endothelial cells as well as fibroblast growth factor (FGF)-induced proliferation of rat aortic smooth muscle cells. At 8 d after MI in PTP1B(-/-) mice, increased LV capillary density (+21±3% vs. WT; P<0.05) and an increased number of small diameter arteries (15-50 µm) were likely to participate in increased LV perfusion assessed by magnetic resonance imaging and improved LV compliance, indicating reduced diastolic dysfunction. In conclusion, PTP1B deficiency reduces MI-induced heart failure promptly after ischemia by enhancing angiogenesis, myocardial perfusion, and diastolic function.


Assuntos
Circulação Coronária/fisiologia , Infarto do Miocárdio/fisiopatologia , Neovascularização Fisiológica/fisiologia , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Animais , Aorta , Arteríolas/fisiopatologia , Capilares/fisiopatologia , Cardiotônicos/farmacologia , Divisão Celular , Movimento Celular , Células Cultivadas , Diástole , Células Endoteliais/patologia , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/prevenção & controle , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Terapia de Alvo Molecular , Infarto do Miocárdio/complicações , Infarto do Miocárdio/enzimologia , Miócitos de Músculo Liso/citologia , Proteína Tirosina Fosfatase não Receptora Tipo 1/deficiência , Proteína Tirosina Fosfatase não Receptora Tipo 1/genética , Proteína Tirosina Fosfatase não Receptora Tipo 1/fisiologia , Interferência de RNA , Ratos , Transdução de Sinais , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/fisiologia , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/fisiopatologia , Remodelação Ventricular
9.
Expert Opin Drug Metab Toxicol ; 9(3): 333-47, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23157726

RESUMO

INTRODUCTION: Among the dimethanesulfonates, busulfan, in combination with other alkylating agents or nucleoside analogues, is the cornerstone of high-dose chemotherapy. It is used, and followed hematopoietic stem cell transplantation, for the treatment of various hematologic malignancies and immunodeficiencies. Treosulfan, which is a hydrophilic analogue of busulfan, was the first dimethanesufonate registered for the treatment of ovarian cancer. Recently, treosulfan has been investigated for the treatment of hematologic malignancies in combination with the same second agents before hematopoietic stem cell transplantation. AREAS COVERED: This work reviews the pharmacological data of these two dimethanesulfonates alkylating agents. Specifically, the article looks at their chemistry, metabolism, anticancer activity, and their pharmacokinetics and pharmacodynamics. EXPERT OPINION: Busulfan has been investigated widely for more than three decades leading to a large and precise handling of this agent with numerous studies on activity and pharmacokinetics and pharmacodynamics. In contrast, the behavior of treosulfan is still under investigation and not fully described. The complexity of treosulfan's metabolism and mechanism of action gives rise to the need of a deeper understanding of its pharmacological activity in a context of high-dose chemotherapy. Specifically, there is a great need to better understand its pharmacokinetics/pharmacodynamics relationship.


Assuntos
Antineoplásicos Alquilantes/farmacocinética , Bussulfano/análogos & derivados , Bussulfano/farmacocinética , Administração Oral , Animais , Antineoplásicos Alquilantes/administração & dosagem , Bussulfano/administração & dosagem , Ciclofosfamida/uso terapêutico , Relação Dose-Resposta a Droga , Feminino , Neoplasias Hematológicas/terapia , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Agonistas Mieloablativos/uso terapêutico , Neoplasias Ovarianas/tratamento farmacológico , Vidarabina/análogos & derivados , Vidarabina/uso terapêutico , Irradiação Corporal Total/métodos
10.
Nat Commun ; 3: 1208, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23169049

RESUMO

Endothelial adherens junctions maintain vascular integrity. Arteries and veins differ in their permeability but whether organization and strength of their adherens junctions vary has not been demonstrated in vivo. Here we report that vascular endothelial cadherin, an endothelial specific adhesion protein located at adherens junctions, is phosphorylated in Y658 and Y685 in vivo in veins but not in arteries under resting conditions. This difference is due to shear stress-induced junctional Src activation in veins. Phosphorylated vascular endothelial-cadherin is internalized and ubiquitinated in response to permeability-increasing agents such as bradykinin and histamine. Inhibition of Src blocks vascular endothelial cadherin phosphorylation and bradykinin-induced permeability. Point mutation of Y658F and Y685F prevents vascular endothelial cadherin internalization, ubiquitination and an increase in permeability by bradykinin in vitro. Thus, phosphorylation of vascular endothelial cadherin contributes to a dynamic state of adherens junctions, but is not sufficient to increase vascular permeability in the absence of inflammatory agents.


Assuntos
Antígenos CD/metabolismo , Caderinas/metabolismo , Permeabilidade Capilar , Hemodinâmica , Sequência de Aminoácidos , Animais , Especificidade de Anticorpos/efeitos dos fármacos , Antígenos CD/imunologia , Artérias/efeitos dos fármacos , Artérias/fisiologia , Bradicinina/farmacologia , Caderinas/imunologia , Permeabilidade Capilar/efeitos dos fármacos , Endocitose/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Mediadores da Inflamação/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Fosforilação/efeitos dos fármacos , Estresse Mecânico , Ubiquitinação/efeitos dos fármacos , Veias/efeitos dos fármacos , Veias/fisiologia , Quinases da Família src/metabolismo
12.
Circulation ; 125(1): 140-9, 2012 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-22086875

RESUMO

BACKGROUND: Increased permeability, predominantly controlled by endothelial junction stability, is an early event in the deterioration of vascular integrity in ischemic disorders. Hemorrhage, edema, and inflammation are the main features of reperfusion injuries, as observed in acute myocardial infarction (AMI). Thus, preservation of vascular integrity is fundamental in ischemic heart disease. Angiopoietins are pivotal modulators of cell-cell junctions and vascular integrity. We hypothesized that hypoxic induction of angiopoietin-like protein 4 (ANGPTL4) might modulate vascular damage, infarct size, and no-reflow during AMI. METHODS AND RESULTS: We showed that vascular permeability, hemorrhage, edema, inflammation, and infarct severity were increased in angptl4-deficient mice. We determined that decrease in vascular endothelial growth factor receptor 2 (VEGFR2) and VE-cadherin expression and increase in Src kinase phosphorylation downstream of VEGFR2 were accentuated after ischemia-reperfusion in the coronary microcirculation of angptl4-deficient mice. Both events led to altered VEGFR2/VE-cadherin complexes and to disrupted adherens junctions in the endothelial cells of angptl4-deficient mice that correlated with increased no-reflow. In vivo injection of recombinant human ANGPTL4 protected VEGF-driven dissociation of the VEGFR2/VE-cadherin complex, reduced myocardial infarct size, and the extent of no-reflow in mice and rabbits. CONCLUSIONS: These data showed that ANGPTL4 might constitute a relevant target for therapeutic vasculoprotection aimed at counteracting the effects of VEGF, thus being crucial for preventing no-reflow and conferring secondary cardioprotection during AMI.


Assuntos
Angiopoietinas/uso terapêutico , Endotélio Vascular/metabolismo , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/prevenção & controle , Fenômeno de não Refluxo/metabolismo , Fenômeno de não Refluxo/prevenção & controle , Proteína 4 Semelhante a Angiopoietina , Angiopoietinas/deficiência , Animais , Cardiotônicos/metabolismo , Cardiotônicos/uso terapêutico , Células Cultivadas , Endotélio Vascular/citologia , Endotélio Vascular/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Infarto do Miocárdio/patologia , Miócitos Cardíacos/metabolismo , Coelhos , Distribuição Aleatória
13.
Nat Med ; 17(10): 1242-50, 2011 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-21946538

RESUMO

Rapidly progressive glomerulonephritis (RPGN) is a life-threatening clinical syndrome and a morphological manifestation of severe glomerular injury that is marked by a proliferative histological pattern ('crescents') with accumulation of T cells and macrophages and proliferation of intrinsic glomerular cells. We show de novo induction of heparin-binding epidermal growth factor-like growth factor (HB-EGF) in intrinsic glomerular epithelial cells (podocytes) from both mice and humans with RPGN. HB-EGF induction increases phosphorylation of the epidermal growth factor receptor (EGFR, also known as ErbB1) in mice with RPGN. In HB-EGF-deficient mice, EGFR activation in glomeruli is absent and the course of RPGN is improved. Autocrine HB-EGF induces a phenotypic switch in podocytes in vitro. Conditional deletion of the Egfr gene from podocytes of mice alleviates the severity of RPGN. Likewise, pharmacological blockade of EGFR also improves the course of RPGN, even when started 4 d after the induction of experimental RPGN. This suggests that targeting the HB-EGF-EGFR pathway could also be beneficial in treatment of human RPGN.


Assuntos
Receptores ErbB/metabolismo , Glomerulonefrite/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Glomérulos Renais/lesões , Glomérulos Renais/fisiopatologia , Insuficiência Renal/etiologia , Análise de Variância , Animais , Western Blotting , Transplante de Medula Óssea , Ensaio de Imunoadsorção Enzimática , Receptores ErbB/genética , Citometria de Fluxo , Glomerulonefrite/complicações , Glomerulonefrite/patologia , Fator de Crescimento Semelhante a EGF de Ligação à Heparina , Humanos , Hibridização In Situ , Peptídeos e Proteínas de Sinalização Intercelular/genética , Glomérulos Renais/citologia , Camundongos , Camundongos Knockout , Microscopia Eletrônica de Transmissão , Microscopia de Fluorescência , Fosforilação , Podócitos/metabolismo , Quinazolinas , Reação em Cadeia da Polimerase em Tempo Real , Estatísticas não Paramétricas , Tirfostinas
14.
J Biol Chem ; 286(42): 36841-51, 2011 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-21832056

RESUMO

Proper vessel maturation, remodeling of endothelial junctions, and recruitment of perivascular cells is crucial for establishing and maintaining vessel functions. In proliferative retinopathies, hypoxia-induced angiogenesis is associated with disruption of the vascular barrier, edema, and vision loss. Therefore, identifying factors that regulate vascular maturation is critical to target pathological angiogenesis. Given the conflicting role of angiopoietin-like-4 (ANGPTL4) reported in the current literature using gain of function systems both in vitro and in vivo, the goal of this study was to characterize angiogenesis, focusing on perinatal retinal vascularization and pathological circumstances in angpl4-deficient mice. We report altered organization of endothelial junctions and pericyte coverage, both leading to impaired angiogenesis and increased vascular leakage that were eventually caught up, suggesting a delay in vessel maturation. In a model of oxygen-induced retinopathy, pathological neovascularization, which results from tissue hypoxia, was also strongly inhibited in angptl4-deficient mice. This study therefore shows that ANGPTL4 tunes endothelial cell junction organization and pericyte coverage and controls vascular permeability and angiogenesis, both during development and in pathological conditions.


Assuntos
Angiopoietinas/metabolismo , Células Endoteliais/metabolismo , Junções Intercelulares/metabolismo , Neovascularização Patológica/embriologia , Pericitos/metabolismo , Retina/embriologia , Neovascularização Retiniana/embriologia , Proteína 4 Semelhante a Angiopoietina , Angiopoietinas/genética , Animais , Permeabilidade Capilar/genética , Células Endoteliais/patologia , Hipóxia/induzido quimicamente , Hipóxia/embriologia , Hipóxia/genética , Hipóxia/patologia , Junções Intercelulares/genética , Junções Intercelulares/patologia , Camundongos , Camundongos Mutantes , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Oxigênio/toxicidade , Pericitos/patologia , Retina/patologia , Neovascularização Retiniana/induzido quimicamente , Neovascularização Retiniana/genética , Neovascularização Retiniana/patologia
16.
J Clin Invest ; 118(5): 1924-33, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18382768

RESUMO

Patients with sickle-cell disease (SCD) suffer from tissue damage and life-threatening complications caused by vasoocclusive crisis (VOC). Endothelin receptors (ETRs) are mediators of one of the most potent vasoconstrictor pathways in mammals, but the relationship between vasoconstriction and VOC is not well understood. We report here that pharmacological inhibition of ETRs prevented hypoxia-induced acute VOC and organ damage in a mouse model of SCD. An in vivo ultrasonographic study of renal hemodynamics showed a substantial increase in endothelin-mediated vascular resistance during hypoxia/reoxygenation-induced VOC. This increase was reversed by administration of the dual ETR antagonist (ETRA) bosentan, which had pleiotropic beneficial effects in vivo. It prevented renal and pulmonary microvascular congestion, systemic inflammation, dense rbc formation, and infiltration of activated neutrophils into tissues with subsequent nitrative stress. Bosentan also prevented death of sickle-cell mice exposed to a severe hypoxic challenge. These findings in mice suggest that ETRA could be a potential new therapy for SCD, as it may prevent acute VOC and limit organ damage in sickle-cell patients.


Assuntos
Anemia Falciforme , Anti-Hipertensivos/uso terapêutico , Antagonistas dos Receptores de Endotelina , Hipóxia , Receptores de Endotelina/metabolismo , Sulfonamidas/uso terapêutico , Anemia Falciforme/metabolismo , Anemia Falciforme/mortalidade , Anemia Falciforme/patologia , Anemia Falciforme/fisiopatologia , Animais , Bosentana , Modelos Animais de Doenças , Endotelina-1/genética , Endotelina-1/metabolismo , Hemodinâmica , Humanos , Rim/citologia , Rim/metabolismo , Rim/patologia , Rim/fisiologia , Pulmão/citologia , Pulmão/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/metabolismo , Receptores de Endotelina/genética , Fluxo Sanguíneo Regional , Circulação Renal/fisiologia , Vasoconstrição/fisiologia
17.
J Clin Invest ; 117(7): 1844-55, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17557121

RESUMO

Tumor radioresponsiveness depends on endothelial cell death, which leads in turn to tumor hypoxia. Radiation-induced hypoxia was recently shown to trigger tumor radioresistance by activating angiogenesis through hypoxia-inducible factor 1-regulated (HIF-1-regulated) cytokines. We show here that combining targeted radioiodide therapy with angiogenic inhibitors, such as canstatin, enhances direct tumor cell apoptosis, thereby overcoming radio-induced HIF-1-dependent tumor survival pathways in vitro and in vivo. We found that following dual therapy, HIF-1alpha increases the activity of the canstatin-induced alpha(v)beta(5) signaling tumor apoptotic pathway and concomitantly abrogates mitotic checkpoint and tetraploidy triggered by radiation. Apoptosis in conjunction with mitotic catastrophe leads to lethal tumor damage. We discovered that HIF-1 displays a radiosensitizing activity that is highly dependent on treatment modalities by regulating key apoptotic molecular pathways. Our findings therefore support a crucial role for angiogenesis inhibitors in shifting the fate of radiation-induced HIF-1alpha activity from hypoxia-induced tumor radioresistance to hypoxia-induced tumor apoptosis. This study provides a basis for developing new biology-based clinically relevant strategies to improve the efficacy of radiation oncology, using HIF-1 as an ally for cancer therapy.


Assuntos
Apoptose/efeitos da radiação , Colágeno Tipo IV/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Fragmentos de Peptídeos/metabolismo , Adenoviridae/genética , Animais , Linhagem Celular , Colágeno Tipo IV/genética , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica , Terapia Genética , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Integrinas/metabolismo , Camundongos , Camundongos Transgênicos , Mitocôndrias/metabolismo , Neoplasias/irrigação sanguínea , Neoplasias/terapia , Fragmentos de Peptídeos/genética , Transdução de Sinais , Simportadores/genética , Simportadores/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Proc Natl Acad Sci U S A ; 103(49): 18721-6, 2006 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-17130448

RESUMO

Angiopoietin-like 4 (ANGPTL4), a secreted protein of the angiopoietin-like family, is induced by hypoxia in both tumor and endothelial cells as well as in hypoxic perinecrotic areas of numerous cancers. Here, we investigated whether ANGPTL4 might affect tumor growth as well as metastasis. Metastatic 3LL cells were therefore xenografted into control mice and mice in which ANGPTL4 was expressed by using in vivo DNA electrotransfer. Whereas primary tumors grew at a similar rate in both groups, 3LL cells metastasized less efficiently to the lungs of mice that expressed ANGPTL4. Fewer 3LL emboli were observed in primary tumors, suggesting that intravasation of 3LL cells was inhibited by ANGPTL4. Furthermore, melanoma B16F0 cells injected into the retro-orbital sinus also metastasized less efficiently in mice expressing ANGPTL4. Although B16F0 cells were observed in lung vessels, they rarely invaded the parenchyma, suggesting that ANGPTL4 affects extravasation. In addition, recombinant B16F0 cells that overexpress ANGPTL4 were generated, showing a lower capacity for in vitro migration, invasion, and adhesion than control cells. Expression of ANGPTL4 induced reorganization of the actin cytoskeleton through inhibition of actin stress fiber formation and vinculin localization at focal contacts. Together, these results show that ANGPTL4, through its action on both vascular and tumor compartments, prevents the metastatic process by inhibiting vascular activity as well as tumor cell motility and invasiveness.


Assuntos
Permeabilidade Capilar/fisiologia , Movimento Celular/fisiologia , Peptídeos e Proteínas de Sinalização Intercelular/fisiologia , Invasividade Neoplásica/prevenção & controle , Metástase Neoplásica/prevenção & controle , Proteína 4 Semelhante a Angiopoietina , Angiopoietinas , Animais , Carcinoma Pulmonar de Lewis/patologia , Carcinoma Pulmonar de Lewis/prevenção & controle , Carcinoma Pulmonar de Lewis/secundário , Linhagem Celular Tumoral , Feminino , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/prevenção & controle , Linfonodos/patologia , Metástase Linfática/patologia , Metástase Linfática/prevenção & controle , Linfopoese/fisiologia , Melanoma Experimental/patologia , Melanoma Experimental/prevenção & controle , Melanoma Experimental/secundário , Camundongos , Camundongos Endogâmicos C57BL , Invasividade Neoplásica/patologia , Metástase Neoplásica/patologia , Neovascularização Fisiológica
19.
Circ Res ; 99(11): 1207-15, 2006 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-17068295

RESUMO

Angiopoietin-like 4 (ANGPTL4) is a secreted protein that belongs to the angiopoietin family and is involved in angiogenesis and metabolism regulation. We previously reported the induction of angptl4 by hypoxia in endothelial cells and in human ischemic tissues from peripheral artery disease. We here observed in a mouse model of hindlimb ischemia that the mRNA upregulation in the vessels correlates with the accumulation of the full-length protein in ischemic tissues. We then investigated its functions in endothelial cells. In response to hypoxia, endogenous ANGPTL4 accumulates in the subendothelial extracellular matrix (ECM). Although the secreted protein undergoes proteolysis leading to truncated fragments present in the medium, only full-length ANGPTL4 interacts with the ECM. Competition and direct binding assays indicate that the strong interaction of ANGPTL4 with the ECM is heparin/heparan sulfate proteoglycan dependent. The balance between matrix-associated and soluble forms of ANGPTL4 points to the role of the ECM in the regulation of its bioavailability. The angiogenic function of the ECM-bound full-length protein was investigated using either the form associated with the conditioned ECM from ANGPTL4-transfected HEK293 cells or the purified immobilized protein. We show that matrix-associated and immobilized ANGPTL4 limit the formation of actin stress fibers and focal contacts in the adhering endothelial cells and inhibit their adhesion. Immobilized ANGPTL4 also decreases motility of endothelial cells and inhibits the sprouting and tube formation. Altogether, these findings show that hypoxic endothelial cells accumulate ANGPTL4 in the ECM, which in turn negatively regulates their angiogenic capacities through an autocrine pathway.


Assuntos
Proteínas Sanguíneas/metabolismo , Citoesqueleto/ultraestrutura , Células Endoteliais/metabolismo , Matriz Extracelular/metabolismo , Membro Posterior/irrigação sanguínea , Hipóxia/fisiopatologia , Isquemia/metabolismo , Neovascularização Fisiológica , Actinas/metabolismo , Proteína 4 Semelhante a Angiopoietina , Angiopoietinas , Animais , Disponibilidade Biológica , Proteínas Sanguíneas/farmacologia , Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Citoesqueleto/efeitos dos fármacos , Heparina/análogos & derivados , Heparina/metabolismo , Hipóxia/metabolismo , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos C57BL , Neovascularização Fisiológica/efeitos dos fármacos , Proteoglicanas/metabolismo
20.
Cancer Res ; 65(10): 4353-61, 2005 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-15899827

RESUMO

Canstatin, the noncollagenous domain of collagen type IV alpha-chains, belongs to a series of collagen-derived angiogenic inhibitors. We have elucidated the functional receptors and intracellular signaling induced by canstatin that explain its strong antitumor efficacy in vivo. For this purpose, we generated a canstatin-human serum albumin (CanHSA) fusion protein, employing the HSA moiety as an expression tag. We show that CanHSA triggers a crucial mitochondrial apoptotic mechanism through procaspase-9 cleavage in both endothelial and tumor cells, which is mediated through cross-talk between alphavbeta3- and alphavbeta5-integrin receptors. As a point of reference, we employed the first three kringle domains of angiostatin (K1-3), fused with HSA, which, in contrast to CanHSA, act only on endothelial cells through alphavbeta3-integrin receptor-mediated activation of caspase-8 alone, without ensuing mitochondrial damage. Taken together, these results provide insights into how canstatin might exert its strong anticancer effect.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Colágeno Tipo IV/farmacologia , Células Endoteliais/efeitos dos fármacos , Integrina alfaVbeta3/metabolismo , Integrinas/metabolismo , Mitocôndrias/efeitos dos fármacos , Receptores de Vitronectina/metabolismo , Inibidores da Angiogênese/metabolismo , Inibidores da Angiogênese/farmacologia , Animais , Apoptose/efeitos dos fármacos , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Caspases/metabolismo , Linhagem Celular Tumoral , Colágeno Tipo IV/genética , Colágeno Tipo IV/metabolismo , Células Endoteliais/enzimologia , Humanos , Isoenzimas , Camundongos , Mitocôndrias/metabolismo , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes de Fusão/farmacologia , Albumina Sérica/genética , Albumina Sérica/metabolismo , Albumina Sérica/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
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