Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Nucl Med ; 65(4): 586-592, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38423788

RESUMO

Glypican-3 (GPC3) is a membrane-associated glycoprotein that is significantly upregulated in hepatocellular carcinomas (HCC) with minimal to no expression in normal tissues. The differential expression of GPC3 between tumor and normal tissues provides an opportunity for targeted radiopharmaceutical therapy to treat HCC, a leading cause of cancer-related deaths worldwide. Methods: DOTA-RYZ-GPC3 (RAYZ-8009) comprises a novel macrocyclic peptide binder to GPC3, a linker, and a chelator that can be complexed with different radioisotopes. The binding affinity was determined by surface plasma resonance and radioligand binding assays. Target-mediated cellular internalization was radiometrically measured at multiple time points. In vivo biodistribution, monotherapy, and combination treatments with 177Lu or 225Ac were performed on HCC xenografts. Results: RAYZ-8009 showed high binding affinity to GPC3 protein of human, mouse, canine, and cynomolgus monkey origins and no binding to other glypican family members. Potent cellular binding was confirmed in GPC3-positive HepG2 cells and was not affected by isotope switching. RAYZ-8009 achieved efficient internalization on binding to HepG2 cells. Biodistribution study of 177Lu-RAYZ-8009 showed sustained tumor uptake and fast renal clearance, with minimal or no uptake in other normal tissues. Tumor-specific uptake was also demonstrated in orthotopic HCC tumors, with no uptake in surrounding liver tissue. Therapeutically, significant and durable tumor regression and survival benefit were achieved with 177Lu- and 225Ac-labeled RAYZ-8009, as single agents and in combination with lenvatinib, in GPC3-positive HCC xenografts. Conclusion: Preclinical in vitro and in vivo data demonstrate the potential of RAYZ-8009 as a theranostic agent for the treatment of patients with GPC3-positive HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Animais , Cães , Camundongos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/radioterapia , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/radioterapia , Neoplasias Hepáticas/metabolismo , Glipicanas/metabolismo , Medicina de Precisão , Distribuição Tecidual , Macaca fascicularis/metabolismo , Peptídeos/metabolismo
2.
J Prim Health Care ; 12(1): 29-34, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32223847

RESUMO

INTRODUCTION Life expectancy in patients with schizophrenia is 15-20 years less than the general population. A dominant cause of morbidity and mortality in these patients is cardiovascular disease. Adverse consequences of modifiable cardiovascular risk factors can be reduced by regular monitoring of metabolic outcomes and intervention if required. AIM To evaluate the metabolic screening in primary care for patients with schizoaffective disorders managed in primary care. To show the usefulness of combining simple practice audits in evaluating such areas of clinical practice. METHODS An audit was undertaken in eight general practices in the Waikato and Bay of Plenty regions of New Zealand. Specifically, the monitoring of patients with schizophrenia or schizoaffective disorder whose antipsychotic medication was prescribed by primary care doctors was audited. Patient monitoring was compared to the guideline recommendation of the Royal Australian and New Zealand College of Psychiatrists (RANZCP) and the Best Practice Advisory Centre (BPAC). RESULTS In total, 117 patients were included in the audit and none were fully monitored, as recommended by the RANZCP guidelines. Although two-thirds of patients had been evaluated for glycosylated haemoglobin (HbA1c), lipids, blood pressure, complete blood count and weight, <10% of patients had had prolactin, waist circumference or electrocardiogram measurements recorded. The proportion of patients having a HbA1c measured was also significantly higher in younger patients and patients who were non-Maori or enrolled with an urban practice (all P<0.05). When using the simplified BPAC guidelines, half of all patients were correctly monitored. DISCUSSION These findings show there is room for improvement in the monitoring of patients receiving antipsychotic medication in primary care. This may indicate the need for clear guidance and general practitioner education around the monitoring requirements of these patients. Alternatively, a more simplified monitoring protocol may need to be developed. This audit has also shown that there is value in several practices completing the same audit and providing a larger cohort of patients for pooled data analysis.


Assuntos
Antipsicóticos/uso terapêutico , Fatores de Risco de Doenças Cardíacas , Programas de Rastreamento/organização & administração , Atenção Primária à Saúde/organização & administração , Transtornos Psicóticos/tratamento farmacológico , Esquizofrenia/tratamento farmacológico , Fatores Etários , Contagem de Células Sanguíneas , Pressão Sanguínea , Pesos e Medidas Corporais , Doenças Cardiovasculares/prevenção & controle , Eletrocardiografia , Feminino , Hemoglobinas Glicadas , Humanos , Expectativa de Vida , Masculino , Programas de Rastreamento/normas , Nova Zelândia , Atenção Primária à Saúde/normas , Prolactina/sangue , Características de Residência , Fatores de Risco
3.
Sci Rep ; 6: 26071, 2016 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-27184415

RESUMO

IL-17A is a pro-inflammatory cytokine that has been implicated in autoimmune and inflammatory diseases. Monoclonal antibodies inhibiting IL-17A signaling have demonstrated remarkable efficacy, but an oral therapy is still lacking. A high affinity IL-17A peptide antagonist (HAP) of 15 residues was identified through phage-display screening followed by saturation mutagenesis optimization and amino acid substitutions. HAP binds specifically to IL-17A and inhibits the interaction of the cytokine with its receptor, IL-17RA. Tested in primary human cells, HAP blocked the production of multiple inflammatory cytokines. Crystal structure studies revealed that two HAP molecules bind to one IL-17A dimer symmetrically. The N-terminal portions of HAP form a ß-strand that inserts between two IL-17A monomers while the C-terminal section forms an α helix that directly blocks IL-17RA from binding to the same region of IL-17A. This mode of inhibition suggests opportunities for developing peptide antagonists against this challenging target.


Assuntos
Inibidores Enzimáticos/metabolismo , Interleucina-17/antagonistas & inibidores , Peptídeos/metabolismo , Receptores de Interleucina-17/metabolismo , Substituição de Aminoácidos , Células Cultivadas , Cristalografia por Raios X , Inibidores Enzimáticos/isolamento & purificação , Humanos , Interleucina-17/química , Programas de Rastreamento , Modelos Moleculares , Mutagênese , Biblioteca de Peptídeos , Peptídeos/química , Peptídeos/isolamento & purificação , Ligação Proteica , Conformação Proteica
4.
Nucleic Acids Res ; 43(19): 9123-32, 2015 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-26446989

RESUMO

The in vivo potency of antisense oligonucleotides (ASO) has been significantly increased by reducing their length to 8-15 nucleotides and by the incorporation of high affinity RNA binders such as 2', 4'-bridged nucleic acids (also known as locked nucleic acid or LNA, and 2',4'-constrained ethyl [cET]). We now report the development of a novel ASO design in which such short ASO monomers to one or more targets are co-synthesized as homo- or heterodimers or multimers via phosphodiester linkers that are stable in plasma, but cleaved inside cells, releasing the active ASO monomers. Compared to current ASOs, these multimers and multi-targeting oligonucleotides (MTOs) provide increased plasma protein binding and biodistribution to liver, and increased in vivo efficacy against single or multiple targets with a single construct. In vivo, MTOs synthesized in both RNase H-activating and steric-blocking oligonucleotide designs provide ≈4-5-fold increased potency and ≈2-fold increased efficacy, suggesting broad therapeutic applications.


Assuntos
Oligonucleotídeos Antissenso/química , Animais , Apolipoproteína C-III/genética , Apolipoproteína C-III/metabolismo , Apolipoproteínas B/genética , Apolipoproteínas B/metabolismo , Dimerização , Feminino , Humanos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , MicroRNAs/antagonistas & inibidores , Oligonucleotídeos Antissenso/farmacocinética , Oligonucleotídeos Antissenso/farmacologia , Distribuição Tecidual
5.
Eur J Med Chem ; 94: 471-9, 2015 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-25109255

RESUMO

Peptide macrocycles represent a chemical space where the best of biological tools can synergize with the best of chemical approaches in the quest for leads against undruggable targets. Peptide macrocycles offer some key advantages in both lead discovery and lead optimization phases of drug discovery when compared to natural product and synthetic macrocycles. In addition, they are uniquely positioned to capitalize on the therapeutic potential of peptides because cyclization can help drive selectivity, potency and overcome the common limitations of metabolic instability of peptides.


Assuntos
Descoberta de Drogas , Compostos Macrocíclicos/farmacologia , Peptídeos/farmacologia , Ciclização , Humanos , Compostos Macrocíclicos/síntese química , Compostos Macrocíclicos/química , Compostos Macrocíclicos/uso terapêutico , Peptídeos/síntese química , Peptídeos/química , Peptídeos/uso terapêutico , Estabilidade Proteica
6.
Bioconjug Chem ; 25(7): 1331-41, 2014 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-24924618

RESUMO

It is becoming increasingly clear that site-specific conjugation offers significant advantages over conventional conjugation chemistries used to make antibody-drug conjugates (ADCs). Site-specific payload placement allows for control over both the drug-to-antibody ratio (DAR) and the conjugation site, both of which play an important role in governing the pharmacokinetics (PK), disposition, and efficacy of the ADC. In addition to the DAR and site of conjugation, linker composition also plays an important role in the properties of an ADC. We have previously reported a novel site-specific conjugation platform comprising linker payloads designed to selectively react with site-specifically engineered aldehyde tags on an antibody backbone. This chemistry results in a stable C-C bond between the antibody and the cytotoxin payload, providing a uniquely stable connection with respect to the other linker chemistries used to generate ADCs. The flexibility and versatility of the aldehyde tag conjugation platform has enabled us to undertake a systematic evaluation of the impact of conjugation site and linker composition on ADC properties. Here, we describe the production and characterization of a panel of ADCs bearing the aldehyde tag at different locations on an IgG1 backbone conjugated using Hydrazino-iso-Pictet-Spengler (HIPS) chemistry. We demonstrate that in a panel of ADCs with aldehyde tags at different locations, the site of conjugation has a dramatic impact on in vivo efficacy and pharmacokinetic behavior in rodents; this advantage translates to an improved safety profile in rats as compared to a conventional lysine conjugate.


Assuntos
Aldeídos/química , Anticorpos Monoclonais/química , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Imunoconjugados/química , Imunoconjugados/farmacocinética , Receptor ErbB-2/imunologia , Animais , Anticorpos Monoclonais/imunologia , Neoplasias da Mama/patologia , Feminino , Humanos , Imunoconjugados/farmacologia , Camundongos , Camundongos SCID , Estrutura Molecular , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Distribuição Tecidual , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Bioconjug Chem ; 25(6): 1052-60, 2014 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-24824568

RESUMO

Peptide conjugates represent an emerging class of therapeutics. However, in contrast to that of small molecules and peptides, the discovery and optimization of peptide conjugates is low in throughput, resource intensive, time-consuming, and based on educated decisions rather than screening. A strategy for the parallel synthesis and screening of peptide conjugates is presented that (1) reduces variability in the conjugation steps; (2) provides a new method to rapidly and quantitatively measure conversion in crude conjugation mixtures; (3) introduces a purification step using an immobilized chemical scavenger that does not rely on protein-specific binding; and (4) is supported by robust analytical methods to characterize the large number of end products. Copper-free click chemistry is used as the chemoselective ligation method for conjugation and purification. The productivity in the generation and screening of peptide conjugates is significantly improved by applying this strategy as is demonstrated by the optimization of the anti-Angiopoietin-2 (Ang2) CovX-body, CVX-060, a peptide-antibody scaffold conjugate that has advanced in clinical trials for oncology indications.


Assuntos
Peptídeos/síntese química , Anticorpos/química , Química Click , Estrutura Molecular , Peptídeos/química , Peptídeos/isolamento & purificação
8.
Bioorg Med Chem Lett ; 23(2): 402-6, 2013 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-23253442

RESUMO

Human growth hormone was conjugated to a carrier aldolase antibody, using a novel linker by connecting a disulphide bond in growth hormone to a lysine-94 amine located on the Fab arm of the antibody. The resulting CovX body showed reduced affinity towards human growth hormone receptor, reduced cell-based activity, but improved pharmacodynamic properties. We have demonstrated that this CovX-body, given once a week, showed comparable activity as growth hormone given daily in an in vivo hypophysectomized rat model.


Assuntos
Desenho de Fármacos , Hormônio do Crescimento Humano/análogos & derivados , Hormônio do Crescimento Humano/administração & dosagem , Animais , Anticorpos/metabolismo , Cristalografia por Raios X , Modelos Animais de Doenças , Esquema de Medicação , Frutose-Bifosfato Aldolase/metabolismo , Humanos , Hipofisectomia , Modelos Moleculares , Estrutura Molecular , Ratos , Fatores de Tempo
9.
Bioorg Med Chem Lett ; 22(13): 4249-53, 2012 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-22664129

RESUMO

We have developed modified maleimide novel linkers with improved chemical stability that could potentially be used in conjugating various pharmacophores such as oligo nucleotides, peptides, and proteins to antibodies to afford novel biologics with well-defined therapeutic benefits and improved pharmacokinetic properties. These linkers expand the array of tools available for bioconjugation of pharmacophores to antibodies.


Assuntos
Anticorpos/imunologia , Maleimidas/química , Portadores de Fármacos/química , Estabilidade de Medicamentos , Glutationa/química , Concentração de Íons de Hidrogênio , Oligonucleotídeos/química , Oligonucleotídeos/metabolismo , Peptídeos/química , Peptídeos/metabolismo , Proteínas/genética , Proteínas/metabolismo , Temperatura
11.
Am J Physiol Regul Integr Comp Physiol ; 302(1): R126-36, 2012 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-22012698

RESUMO

Calorie restriction [CR; ∼40% below ad libitum (AL) intake] improves the health of many species, including rats, by mechanisms that may be partly related to enhanced insulin sensitivity for glucose disposal by skeletal muscle. Excessive activation of several mitogen-activated protein kinases (MAPKs), including JNK1/2, p38, and ERK1/2 has been linked to insulin resistance. Although insulin can activate ERK1/2, this effect is not required for insulin-mediated glucose uptake. We hypothesized that skeletal muscle from male 9-mo-old Fischer 344/Brown Norway rats CR (35-40% beginning at 3 mo old) versus AL rats would have 1) attenuated activation of JNK1/2, p38, and ERK1/2 under basal conditions; and 2) no difference for insulin-induced ERK1/2 activation. In contrast to our hypothesis, there were significant CR-related increases in the phosphorylation of p38 (epitrochlearis, soleus, and gastrocnemius), JNK1 (epitrochlearis and soleus), and JNK2 (gastrocnemius). Consistent with our hypothesis, CR did not alter insulin-mediated ERK1/2 activation. The greater JNK1/2 and p38 phosphorylation with CR was not attributable to diet effects on muscle oxidative stress (assessed by protein carbonyls and 4-hydroxynonenal protein conjugates). In muscles from the same rats used for the present study, we previously reported a CR-related increase in insulin-mediated glucose uptake by the epitrochlearis and the soleus (Sharma N, Arias EB, Bhat AD, Sequea DA, Ho S, Croff KK, Sajan MP, Farese RV, Cartee GD. Am J Physiol Endocrinol Metab 300: E966-E978, 2011). The present results indicate that the improved insulin sensitivity with CR is not attributable to attenuated MAPK phosphorylation in skeletal muscle.


Assuntos
Restrição Calórica , Resistência à Insulina/fisiologia , Sistema de Sinalização das MAP Quinases/fisiologia , Proteína Quinase 8 Ativada por Mitógeno/metabolismo , Proteína Quinase 9 Ativada por Mitógeno/metabolismo , Músculo Esquelético/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Peso Corporal/fisiologia , Ingestão de Alimentos/fisiologia , Quinase 3 da Glicogênio Sintase/metabolismo , Proteínas I-kappa B/metabolismo , Masculino , Modelos Animais , Inibidor de NF-kappaB alfa , Fosforilação , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos F344 , Serina-Treonina Quinases TOR/metabolismo
12.
Am J Physiol Endocrinol Metab ; 300(6): E966-78, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21386065

RESUMO

Calorie restriction [CR; ~65% of ad libitum (AL) intake] improves insulin-stimulated glucose uptake (GU) and Akt phosphorylation in skeletal muscle. We aimed to elucidate the effects of CR on 1) processes that regulate Akt phosphorylation [insulin receptor (IR) tyrosine phosphorylation, IR substrate 1-phosphatidylinositol 3-kinase (IRS-PI3K) activity, and Akt binding to regulatory proteins (heat shock protein 90, Appl1, protein phosphatase 2A)]; 2) Akt substrate of 160-kDa (AS160) phosphorylation on key phosphorylation sites; and 3) atypical PKC (aPKC) activity. Isolated epitrochlearis (fast-twitch) and soleus (slow-twitch) muscles from AL or CR (6 mo duration) 9-mo-old male F344BN rats were incubated with 0, 1.2, or 30 nM insulin and 2-deoxy-[(3)H]glucose. Some CR effects were independent of insulin dose or muscle type: CR caused activation of Akt (Thr(308) and Ser(473)) and GU in both muscles at both insulin doses without CR effects on IRS1-PI3K, Akt-PP2A, or Akt-Appl1. Several muscle- and insulin dose-specific CR effects were revealed. Akt-HSP90 binding was increased in the epitrochlearis; AS160 phosphorylation (Ser(588) and Thr(642)) was greater for CR epitrochlearis at 1.2 nM insulin; and IR phosphorylation and aPKC activity were greater for CR in both muscles with 30 nM insulin. On the basis of these data, our working hypothesis for improved insulin-stimulated GU with CR is as follows: 1) elevated Akt phosphorylation is fundamental, regardless of muscle or insulin dose; 2) altered Akt binding to regulatory proteins (HSP90 and unidentified Akt partners) is involved in the effects of CR on Akt phosphorylation; 3) Akt effects on GU depend on muscle- and insulin dose-specific elevation in phosphorylation of Akt substrates, including, but not limited to, AS160; and 4) greater IR phosphorylation and aPKC activity may contribute at higher insulin doses.


Assuntos
Restrição Calórica , Glucose/metabolismo , Hipoglicemiantes/farmacologia , Insulina/farmacologia , Fibras Musculares de Contração Rápida/metabolismo , Fibras Musculares de Contração Lenta/metabolismo , Proteína Oncogênica v-akt/metabolismo , Adenilato Quinase/metabolismo , Animais , Western Blotting , Peso Corporal/fisiologia , Desoxiglucose/metabolismo , Ingestão de Alimentos/fisiologia , Transportador de Glucose Tipo 4/metabolismo , Imunoprecipitação , Proteínas Substratos do Receptor de Insulina/metabolismo , Fibras Musculares de Contração Rápida/efeitos dos fármacos , Fibras Musculares de Contração Lenta/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas/metabolismo , Ratos
13.
Clin Cancer Res ; 17(5): 1001-11, 2011 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-21233403

RESUMO

PURPOSE: Angiopoietin-1 (Ang1) plays a key role in maintaining stable vasculature, whereas in a tumor Ang2 antagonizes Ang1's function and promotes the initiation of the angiogenic switch. Specifically targeting Ang2 is a promising anticancer strategy. Here we describe the development and characterization of a new class of biotherapeutics referred to as CovX-Bodies, which are created by chemical fusion of a peptide and a carrier antibody scaffold. EXPERIMENTAL DESIGN: Various linker tethering sites on peptides were examined for their effect on CovX-Body in vitro potency and pharmacokinetics. Ang2 CovX-Bodies with low nmol/L IC(50)s and significantly improved pharmacokinetics were tested in tumor xenograft studies alone or in combination with standard of care agents. Tumor samples were analyzed for target engagement, via Ang2 protein level, CD31-positive tumor vasculature, and Tie2 expressing monocyte penetration. RESULTS: Bivalent Ang2 CovX-Bodies selectively block the Ang2-Tie2 interaction (IC(50) < 1 nmol/L) with dramatically improved pharmacokinetics (T(½) > 100 hours). Using a staged Colo-205 xenograft model, significant tumor growth inhibition (TGI) was observed (40%-63%, P < 0.01). Ang2 protein levels were reduced by approximately 50% inside tumors (P < 0.01), whereas tumor microvessel density (P < 0.01) and intratumor proangiogenic Tie2(+)CD11b(+) cells (P < 0.05) were significantly reduced. When combined with sunitinib, sorafenib, bevacizumab, irinotecan, or docetaxel, Ang2 CovX-Bodies produced even greater efficacy (∼80% TGI, P < 0.01). CONCLUSION: CovX-Bodies provide an elegant solution to overcome the pharmacokinetic-pharmacodynamic problems of peptides. Long-acting Ang2 specific CovX-Bodies will be useful as single agents and in combination with standard-of-care agents.


Assuntos
Inibidores da Angiogênese/farmacologia , Angiopoietina-2/antagonistas & inibidores , Imunoconjugados/farmacologia , Neoplasias Experimentais/tratamento farmacológico , Neovascularização Patológica/metabolismo , Peptídeos/uso terapêutico , Receptores Proteína Tirosina Quinases/metabolismo , Inibidores da Angiogênese/farmacocinética , Inibidores da Angiogênese/uso terapêutico , Angiopoietina-2/metabolismo , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Antígeno CD11b/análise , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Expressão Gênica , Humanos , Imunoconjugados/farmacocinética , Imunoconjugados/uso terapêutico , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Monócitos , Neoplasias Experimentais/patologia , Molécula-1 de Adesão Celular Endotelial a Plaquetas/análise , Ratos , Ratos Sprague-Dawley , Receptores Proteína Tirosina Quinases/genética , Receptor TIE-2 , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Proc Natl Acad Sci U S A ; 107(52): 22611-6, 2010 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-21149738

RESUMO

Bispecific antibodies (BsAbs) are regarded as promising therapeutic agents due to their ability to simultaneously bind two different antigens. Several bispecific modalities have been developed, but their utility is limited due to problems with stability and manufacturing complexity. Here we report a versatile technology, based on a scaffold antibody and pharmacophore peptide heterodimers, that enables rapid generation and chemical optimization of bispecific antibodies, which are termed bispecific CovX-Bodies. Two different peptides are joined together using a branched azetidinone linker and fused to the scaffold antibody under mild conditions in a site-specific manner. Whereas the pharmacophores are responsible for functional activities, the antibody scaffold imparts long half-life and Ig-like distribution. The pharmacophores can be chemically optimized or replaced with other pharmacophores to generate optimized or unique bispecific antibodies. As a prototype, we developed a bispecific antibody that binds both vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang2) simultaneously, inhibits their function, shows efficacy in tumor xenograft studies, and greatly augments the antitumor effects of standard chemotherapy. This unique antiangiogenic bispecific antibody is in phase-1 clinical trials.


Assuntos
Angiopoietina-2/imunologia , Anticorpos Biespecíficos/imunologia , Anticorpos Biespecíficos/farmacologia , Fator A de Crescimento do Endotélio Vascular/imunologia , Sequência de Aminoácidos , Angiopoietina-2/química , Angiopoietina-2/metabolismo , Animais , Anticorpos Biespecíficos/metabolismo , Especificidade de Anticorpos , Antineoplásicos/imunologia , Antineoplásicos/farmacologia , Azetidinas/química , Linhagem Celular Tumoral , Ensaio de Imunoadsorção Enzimática , Humanos , Fatores Imunológicos/imunologia , Fatores Imunológicos/metabolismo , Fatores Imunológicos/farmacocinética , Macaca fascicularis , Masculino , Camundongos , Camundongos Nus , Dados de Sequência Molecular , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Neoplasias/patologia , Ligação Proteica , Ratos , Ratos Sprague-Dawley , Ressonância de Plasmônio de Superfície , Carga Tumoral/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/química , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Nat Rev Cancer ; 10(8): 575-85, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20651738

RESUMO

Angiopoietins (ANGPTs) are ligands of the endothelial cell receptor TIE2 and have crucial roles in the tumour angiogenic switch. Increased expression of ANGPT2 relative to ANGPT1 in tumours correlates with poor prognosis. The biological effects of the ANGPT-TIE system are context dependent, which brings into question what the best strategy is to target this pathway. This Review presents an encompassing picture of what we know about this important axis in tumour biology. The various options for therapeutic intervention are discussed to identify the best path forwards.


Assuntos
Angiopoietinas/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Receptor TIE-2/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Angiopoietinas/fisiologia , Animais , Humanos , Inflamação/etiologia , Linfangiogênese , Metástase Neoplásica , Neoplasias/irrigação sanguínea , Neovascularização Patológica/etiologia , Receptor TIE-2/fisiologia , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores
16.
J Appl Physiol (1985) ; 108(6): 1631-40, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20339009

RESUMO

The slow-twitch soleus, but not fast-twitch muscle, of old vs. adult rats has previously been demonstrated to become insulin resistant for in vivo glucose uptake. We probed cellular mechanisms for the age effect by assessing whether insulin resistance for glucose uptake was an intrinsic characteristic of the muscle ex vivo and by analyzing key insulin signaling steps. We hypothesized that isolated soleus and epitrochlearis (fast-twitch) muscles from old (25 mo) vs. adult (9 mo) male Fisher-344 x Brown Norway rats would have insulin resistance for Akt2 Thr308 phosphorylation (pAkt2Thr308), AS160 phosphorylation Thr642 (pAS160Thr642), and atypical PKC (aPKCzeta/lambda) activity corresponding in magnitude to the extent of insulin resistance for [3H]-2-deoxyglucose (2-DG) uptake. Epitrochlearis insulin-stimulated 2-DG uptake above basal values was unaltered by age, and epitrochlearis pAkt2Thr308, pAS160Thr642, and aPKCzeta/lambda activity were not significantly different in adult vs. old rats. Conversely, insulin-stimulated 2-DG uptake by the soleus of old vs. adult rats was reduced with 1.2 nM (42%) and 30 nM (28%) insulin concomitant with an age-related decline in pAkt2Thr308 of the insulin-stimulated soleus. There were no age effects on pAS160Thr642 or aPKCzeta/lambda activity or abundance of Akt2, AS160, GLUT4 or Appl1 protein in either muscle. The results suggest the possibility that an age-related decline in pAkt2Thr308, acting by a mechanism other than reduced pAS160Thr642, may play a role in the insulin resistance in the soleus of old rats. Skeletal muscle insulin resistance in old age is distinctive compared with other insulin-resistant rodent models that are not selective for greater insulin resistance in the soleus vs. the epitrochlearis.


Assuntos
Envelhecimento/fisiologia , Glucose/farmacocinética , Resistência à Insulina/fisiologia , Músculo Esquelético/fisiologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Masculino , Fosforilação , Ratos , Ratos Endogâmicos F344
17.
J Med Chem ; 46(7): 1120-2, 2003 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-12646020

RESUMO

The regulation of lipid metabolism and it's effect on glucose control and diabetes has received intense interest. Hormone-sensitive lipase (HSL) is a vital enzyme in lipid metabolism. A series of novel pyrrolopyrazinediones has been discovered that demonstrate submicromolar activity both in the enzyme assay and in a (14)C-emulsion assay employing cholesteryl oleate as a substrate as a secondary measure of HSL activity. These compounds represent novel inhibitors of the human HSL enzyme.


Assuntos
Inibidores Enzimáticos/síntese química , Pirazinas/síntese química , Esterol Esterase/antagonistas & inibidores , Animais , Linhagem Celular , Bases de Dados Factuais , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Insetos/citologia , Pirazinas/química , Pirazinas/farmacologia , Relação Estrutura-Atividade
18.
Bioorg Med Chem ; 10(3): 625-37, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11814851

RESUMO

Interactions of recombinant gp120 (rgp120) with non-natural glycosphingolipids (GSLs) and structurally simpler analogues have been studied using a competitive adhesion assay. Conjugates of cellobiosyl ceramide and melibiosyl ceramide were synthetically prepared as water-soluble GSL analogues. These ligands were screened against a panel of biologically relevant analogues, and the results show that their interactions with rgp120 are comparable to natural cellular receptors. Glycolipid interactions with rgp120 were probed further by the synthesis and testing of structurally simpler analogues that were obtained by reductive amination of lactose, cellobiose, and melibiose with a biotinylated amino ethylene glycol moiety. RGp120 did not recognize conjugates lacking a lipid component. However, palmitoylation of the secondary amino alditols yielded compounds with comparable rgp120 affinity to the natural cellular receptor, galactosyl ceramide (GalCer). Taken together, the SAR showed that both a hydrophobic and a hydrophilic component are required for rgp120 recognition. Moreover, structural variability in the carbohydrate headgroup did not significantly alter rgp120 recognition indicating that this interaction is not highly specific.


Assuntos
Glicoesfingolipídeos/síntese química , Proteína gp120 do Envelope de HIV/metabolismo , Ligação Competitiva , Glicoesfingolipídeos/farmacocinética , Humanos , Ligação Proteica , Proteínas Recombinantes/metabolismo , Relação Estrutura-Atividade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...