RESUMO
The development of theranostic radiotracers relies on their binding to specific molecular markers of a particular disease and the use of corresponding radiopharmaceutical pairs thereafter. This study reports the use of multiamine macrocyclic moieties (MAs), as linkers or chelators, in tracers targeting the neurotensin receptor-1 (NTSR-1). The goal is to achieve elevated tumor uptake, minimal background interference, and prolonged tumor retention in NTSR-1-positive tumors. Methods: We synthesized a series of neurotensin antagonists bearing MA linkers and metal chelators. The MA unit is hypothesized to establish a strong interaction with the cell membrane, and the addition of a second chelator may enhance water solubility, consequently reducing liver uptake. Small-animal PET/CT imaging of [64Cu]Cu-DOTA-SR-3MA, [64Cu]Cu-NT-CB-NOTA, [68Ga]Ga-NT-CB-NOTA, [64Cu]Cu-NT-CB-DOTA, and [64Cu]Cu-NT-Sarcage was acquired at 1, 4, 24, and 48 h after injection using H1299 tumor models. [55Co]Co-NT-CB-NOTA was also tested in HT29 (high NTSR-1 expression) and Caco2 (low NTSR-1 expression) colorectal adenocarcinoma tumor models. Saturation binding assay and internalization of [55Co]Co-NT-CB-NOTA were used to test tracer specificity and internalization in HT29 cells. Results: In vivo PET imaging with [64Cu]Cu-NT-CB-NOTA, [68Ga]Ga-NT-CB-NOTA, and [55Co]Co-NT-CB-NOTA revealed high tumor uptake, high tumor-to-background contrast, and sustained tumor retention (≤48 h after injection) in NTSR-1-positive tumors. Tumor uptake of [64Cu]Cu-NT-CB-NOTA remained at 76.9% at 48 h after injection compared with uptake 1 h after injection in H1299 tumor models, and [55Co]Co-NT-CB-NOTA was retained at 60.2% at 24 h compared with uptake 1 h after injection in HT29 tumor models. [64Cu]Cu-NT-Sarcage also showed high tumor uptake with low background and high tumor retention 48 h after injection Conclusion: Tumor uptake and pharmacokinetic properties of NTSR-1-targeting radiopharmaceuticals were greatly improved when attached with different nitrogen-containing macrocyclic moieties. The study results suggest that NT-CB-NOTA labeled with either 64Cu/67Cu, 55Co/58mCo, or 68Ga (effect of 177Lu in tumor to be determined in future studies) and NT-Sarcage labeled with 64Cu/67Cu or 55Co/58mCo may be excellent diagnostic and therapeutic radiopharmaceuticals targeting NTSR-1-positive cancers. Also, the introduction of MA units to other ligands is warranted in future studies to test the generality of this approach.
Assuntos
Radioisótopos de Cobre , Radioisótopos de Gálio , Compostos Macrocíclicos , Compostos Radiofarmacêuticos , Receptores de Neurotensina , Receptores de Neurotensina/metabolismo , Receptores de Neurotensina/antagonistas & inibidores , Animais , Camundongos , Compostos Radiofarmacêuticos/farmacocinética , Compostos Radiofarmacêuticos/química , Distribuição Tecidual , Humanos , Compostos Macrocíclicos/química , Compostos Macrocíclicos/farmacocinética , Marcação por Isótopo , Linhagem Celular Tumoral , Aminas/química , Medicina de Precisão , Radioquímica , Técnicas de Química Sintética , Tomografia por Emissão de Pósitrons combinada à Tomografia ComputadorizadaRESUMO
Strong expression of the G protein-coupled receptor (GPCR) neurotensin receptor 1 (NTR1) in ventral tegmental area (VTA) dopamine (DA) neurons and terminals makes it an attractive target to modulate DA neuron activity and normalize DA-related pathologies. Recent studies have identified a novel class of NTR1 ligand that shows promising effects in preclinical models of addiction. A lead molecule, SBI-0654553 (SBI-553), can act as a positive allosteric modulator of NTR1 ß-arrestin recruitment while simultaneously antagonizing NTR1 Gq protein signaling. Using cell-attached recordings from mouse VTA DA neurons we discovered that, unlike neurotensin (NT), SBI-553 did not independently increase spontaneous firing. Instead, SBI-553 blocked the NT-mediated increase in firing. SBI-553 also antagonized the effects of NT on dopamine D2 auto-receptor signaling, potentially through its inhibitory effects on G-protein signaling. We also measured DA release directly, using fast-scan cyclic voltammetry in the nucleus accumbens and observed antagonist effects of SBI-553 on an NT-induced increase in DA release. Further, in vivo administration of SBI-553 did not notably change basal or cocaine-evoked DA release measured in NAc using fiber photometry. Overall, these results indicate that SBI-553 blunts NT's effects on spontaneous DA neuron firing, D2 auto-receptor function, and DA release, without independently affecting these measures. In the presence of NT, SBI-553 has an inhibitory effect on mesolimbic DA activity, which could contribute to its efficacy in animal models of psychostimulant use.
Assuntos
Antagonistas dos Receptores de Dopamina D2 , Dopamina , Neurônios Dopaminérgicos , Neurotensina , Núcleo Accumbens , Receptores de Neurotensina , Área Tegmentar Ventral , Área Tegmentar Ventral/metabolismo , Área Tegmentar Ventral/fisiologia , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/fisiologia , Núcleo Accumbens/metabolismo , Dopamina/metabolismo , Masculino , Feminino , Animais , Camundongos , Camundongos Endogâmicos C57BL , Terminações Pré-Sinápticas/metabolismo , Terminações Pré-Sinápticas/fisiologia , Potenciais de Ação/efeitos dos fármacos , Receptores de Neurotensina/antagonistas & inibidores , Receptores de Neurotensina/metabolismo , Neurotensina/metabolismo , Neurotensina/farmacologia , Ligantes , Antagonistas dos Receptores de Dopamina D2/metabolismo , Antagonistas dos Receptores de Dopamina D2/farmacologiaRESUMO
Xenin-25 has a variety of physiological functions in the gastrointestinal tract, including ion transport and motility. Xenin-25 and neurotensin show sequence homology, especially near their C-terminal regions. The sequence similarity between xenin-25 and neurotensin indicates that the effects of xenin-25 is mediated by the neurotensin receptor but some biological actions of xenin-25 are independent. We have previously reported that xenin-25 modulates intestinal ion transport and colonic smooth muscle activity. However, minimal biological domain of xenin-25 to induce ion transport was not clear. To improve the mechanistic understanding of xenin-25 and to gain additional insights into the functions of xenin-25, the present study was designed to determine the minimal biological domain of xenin-25 required for ion transport in the rat ileum using various truncated xenin fragments and analogues in an Ussing chamber system. The present results demonstrate that the minimum biological domain of xenin-25 to induce Cl-/HCO3- secretion in the ileum contains the C-terminal pentapeptide. Furthermore, Arg at position 21 is important to retain the biological activity of xenin-25 and induces Cl-/HCO3- secretion in the rat ileum.
Assuntos
Ânions/metabolismo , Íleo/metabolismo , Neurotensina/metabolismo , Animais , Íleo/efeitos dos fármacos , Masculino , Neurotensina/análogos & derivados , Neurotensina/genética , Neurotensina/farmacologia , Domínios Proteicos , Pirazóis/farmacologia , Quinolinas/farmacologia , Ratos Sprague-Dawley , Receptores de Neurotensina/antagonistas & inibidoresRESUMO
Introduction: Neurotensin is a gut-brain peptide hormone, a 13 amino acid neuropeptide found in the central nervous system and in the GI tract. The neurotensinergic system is implicated in various physiological and pathological processes related to neuropsychiatric and metabolic machineries, cancer growth, food, and drug intake. NT mediates its functions through its two G protein-coupled receptors: neurotensin receptor 1 (NTS1/NTSR1) and neurotensin receptor 2 (NTS2/NTSR2). Over the past decade, the role of NTS3/NTSR3/sortilin has also gained importance in human pathologies. Several approaches have appeared dealing with the discovery of compounds able to modulate the functions of this neuropeptide through its receptors for therapeutic gain.Areas covered: The article provides an overview of over four decades of research and details the drug discovery approaches and patented strategies targeting NTSR in the past decade.Expert opinion: Neurotensin is an important neurotransmitter that enables crosstalk with various neurotransmitter and neuroendocrine systems. While significant efforts have been made that have led to selective agonists and antagonists with promising in vitro and in vivo activities, the therapeutic potential of compounds targeting the neurotensinergic system is still to be fully harnessed for successful clinical translation of compounds for the treatment of several pathologies.
Assuntos
Neurotensina/metabolismo , Receptores de Neurotensina/agonistas , Receptores de Neurotensina/antagonistas & inibidores , Animais , Descoberta de Drogas , Humanos , Terapia de Alvo Molecular , Patentes como Assunto , Receptor Cross-Talk , Receptores de Neurotensina/metabolismoRESUMO
Exogenous treatment of a neurotensin receptor 1 (NTR1) agonist exerted the neuroprotection in an obese and Alzheimer's model. However, the effects of NTR1 modulation on peripheral/hippocampal impairment and cognitive deficit following sustained HFD consumption are poorly understood. Forty rats received a normal diet (ND) or HFD for 16 weeks. At week 13, the ND group received a vehicle (n = 8). Thirty-two HFD-fed group were randomized into four subgroups (n = 8/subgroup) with a vehicle, 1 mg/kg of NTR1 agonist, 1 mg/kg of NTR antagonist, and combined treatment (NTR1 agonist-NTR antagonist) for 2 weeks, s.c. injection. Then, the cognitive tests and peripheral/hippocampal parameters were determined. Our findings demonstrated that NTR1 activator reversed obesity and attenuated metabolic impairment in pre-diabetic rats. It also alleviated hippocampal pathologies and synaptic dysplasticity, leading to deceleration or prevention of cognitive impairment progression. Therefore, NTR1 activation would be a possible novel therapy to decelerate or prevent progression of neuropathology and cognitive impairment in the pre-diabetes.
Assuntos
Adamantano/análogos & derivados , Disfunção Cognitiva/tratamento farmacológico , Hipocampo/efeitos dos fármacos , Imidazóis/uso terapêutico , Obesidade/tratamento farmacológico , Oligopeptídeos/uso terapêutico , Receptores de Neurotensina/agonistas , Adamantano/farmacologia , Adamantano/uso terapêutico , Animais , Disfunção Cognitiva/etiologia , Dieta Hiperlipídica , Avaliação Pré-Clínica de Medicamentos , Quimioterapia Combinada , Hipocampo/metabolismo , Íleo/efeitos dos fármacos , Íleo/metabolismo , Imidazóis/farmacologia , Resistência à Insulina , Masculino , Plasticidade Neuronal/efeitos dos fármacos , Obesidade/complicações , Oligopeptídeos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Estado Pré-Diabético/tratamento farmacológico , Estado Pré-Diabético/metabolismo , Distribuição Aleatória , Ratos Wistar , Receptores de Neurotensina/antagonistas & inibidores , Receptores de Neurotensina/metabolismoRESUMO
The central neurotensin system has been implicated in reward, memory processes, also in the regulation of anxiety. However, the neural substrates where neurotensin acts to regulate anxiety have not been fully identified. The prelimbic region of medial prefrontal cortex (PrL) holds a key position in the modulation of anxiety-related behaviors and expresses neurotensin 1 receptor (NTS1). This study investigated the effects of activation or blockade of NTS1 in the PrL on anxiety-like behaviors of rats. Our results demonstrated that infusion of a selective NTS1 agonist or neurotensin into the PrL produced anxiogenic-like effects. Administration of a NTS1 antagonist into the PrL did not affect anxiety-like behaviors of normal rats, but attenuated anxiogenic effects induced by restraint stress. Moreover, we employed molecular approaches to downregulate the expression of NTS1 in the PrL, and found that downregulation of NTS1 in the PrL induced anxiolytic effects in restraint stress rats, also confirming the pharmacological results. Together, these findings suggest that NTS1 in the PrL is actively involved in the regulation of anxiety.
Assuntos
Ansiedade/metabolismo , Córtex Pré-Frontal/metabolismo , Receptores de Neurotensina/metabolismo , Animais , Ansiedade/induzido quimicamente , Ansiedade/tratamento farmacológico , Leucina/administração & dosagem , Leucina/análogos & derivados , Masculino , Microinjeções/métodos , Oligopeptídeos/administração & dosagem , Córtex Pré-Frontal/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Receptores de Neurotensina/agonistas , Receptores de Neurotensina/antagonistas & inibidores , Estresse Psicológico/induzido quimicamente , Estresse Psicológico/tratamento farmacológico , Estresse Psicológico/metabolismo , Sulfonamidas/administração & dosagemRESUMO
Undifferentiated pleomorphic sarcoma (UPS) is the second most common soft tissue sarcoma. For patients with unresectable or metastatic disease, chemotherapies are considered, but in many cases they are not curative. There is a need to identify specific molecular dysregulations that can be therapeutic targets. We focused on neurotensin receptor 1 (NTSR1), which belongs to the G-protein-coupled receptor. NTSR1 expression was upregulated in specimens from patients with UPS. Real-time polymerase chain reaction showed that expression of NTSR1 messenger RNA was 5- to 7-fold increased in UPS cells compared with myoblasts. Western blot showed a high expression of NTSR1 protein in UPS cell lines. Knockdown of NTSR1 prevented UPS cell proliferation and invasion. We confirmed that SR48692, an inhibitor of NTSR1, exhibited antitumor activities in UPS cells. The combination index showed that SR48692 and standard chemotherapeutic drugs prevented UPS cell proliferation synergistically. Mouse xenograft models showed that SR48692 inhibited extracellular signal-regulated kinase phosphorylation and enhanced the response to standard chemotherapeutic drugs. Inhibition of NTSR1 improved the effect of standard chemotherapeutic drugs for UPS. SR48692 may be a new drug for targeted UPS therapy.
Assuntos
Regulação Neoplásica da Expressão Gênica/genética , Receptores de Neurotensina/genética , Sarcoma/genética , Regulação para Cima/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Sinergismo Farmacológico , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Terapia de Alvo Molecular/métodos , Panobinostat/farmacologia , Pirazóis/farmacologia , Quinolinas/farmacologia , Receptores de Neurotensina/antagonistas & inibidores , Receptores de Neurotensina/metabolismo , Sarcoma/tratamento farmacológico , Sarcoma/metabolismo , Regulação para Cima/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto/métodosRESUMO
Neurotensin receptor 1 (NTR1) is a G protein coupled receptor that is widely expressed throughout the central nervous system where it acts as a neuromodulator. Neurotensin receptors have been implicated in a wide variety of CNS disorders, but despite extensive efforts to develop small molecule ligands there are few reports of such compounds. Herein we describe the optimization of a quinazoline based lead to give 18 (SBI-553), a potent and brain penetrant NTR1 allosteric modulator.
Assuntos
Doenças do Sistema Nervoso Central/tratamento farmacológico , Descoberta de Drogas , Quinazolinas/farmacologia , Receptores de Neurotensina/antagonistas & inibidores , beta-Arrestinas/farmacologia , Administração Oral , Regulação Alostérica/efeitos dos fármacos , Animais , Disponibilidade Biológica , Doenças do Sistema Nervoso Central/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/deficiência , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Relação Dose-Resposta a Droga , Feminino , Locomoção/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Estrutura Molecular , Quinazolinas/administração & dosagem , Quinazolinas/química , Ratos , Receptores de Neurotensina/metabolismo , Relação Estrutura-Atividade , beta-Arrestinas/administração & dosagem , beta-Arrestinas/químicaRESUMO
Overall survival of patients with metastatic non-small cell lung cancer (NSCLC) has significantly improved with platinum-based salt treatments and recently with targeted therapies and immunotherapies. However, treatment failure occurs due to acquired or emerging tumor resistance. We developed a monoclonal antibody against the proform of neurotensin (LF-NTS mAb) that alters the homeostasis of tumors overexpressing NTSR1. Neurotensin is frequently overexpressed along with its high affinity receptor (NTSR1) in tumors from epithelial origins. This ligand/receptor complex contributes to the progression of many tumor types by activation of the cellular effects involved in tumor progression (proliferation, survival, migration, and invasion). We demonstrate that LF-NTS mAb operates on the plasticity of tumor cells overexpressing NTSR1 and lowers their aggressiveness. The mAb enables the restoration of platinum-based therapies responsiveness, while also decreasing metastatic processes. Efficacy dosage with long-term treatment showed no obvious adverse events, while demonstrating improvement in the performance status. Our data suggests that LF-NTS mAb is an ideal candidate to be safely added to the conventional standard of care in order to improve its efficacy.
Assuntos
Adenocarcinoma de Pulmão/tratamento farmacológico , Anticorpos Monoclonais/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos , Neurotensina/antagonistas & inibidores , Receptores de Neurotensina/antagonistas & inibidores , Adenocarcinoma de Pulmão/imunologia , Adenocarcinoma de Pulmão/metabolismo , Adenocarcinoma de Pulmão/patologia , Animais , Antineoplásicos/farmacologia , Apoptose , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Proliferação de Células , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Neurotensina/imunologia , Neurotensina/metabolismo , Prognóstico , Receptores de Neurotensina/imunologia , Receptores de Neurotensina/metabolismo , Estudos Retrospectivos , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Molecular dynamics (MD) simulation using the AMBER force field has been performed on the neurotensin (NT) receptor, a class A type G-protein-coupled receptor in its activated conformation co-crystallized with the non-peptide agonists. For structure-based hit molecule identification via natural chemical compound library, orthosteric sites on NT receptor have been mapped by docking using AutoDock4.0 and Vina with the known agonists and antagonists SR48692, SR142948, ML301 and ML314 of the receptor. Furthermore, clustering analysis on the MD trajectories by SIMULAID has been performed to filter receptor conformations for the allosteric binders from the Otava natural compound library. Comparative mappings of contrasting binding region patterns have been done between the crystal structure orthosteric sites as well as the binding regions in the SIMULAID-based cluster center conformations from MD trajectories with the FTmap server using the small organic molecule fragments as the probes. The distinct binding region in the cluster-based conformations in the extracellular region of the receptor has been identified for targeted docking by Otava natural chemical compound library using AutoDock4.0 and Vina docking suites to obtain putative allosteric binders. A group of compounds from the Otava library has been identified as showing high free energy in both AutoDock4.0 and Vina docking suites. Biophysical assessments on the natural compound computational hit molecules will be done to identify lead structures from the hit molecules. Communicated by Ramaswamy H. Sarma.
Assuntos
Produtos Biológicos/análise , Produtos Biológicos/metabolismo , Avaliação Pré-Clínica de Medicamentos , Receptores de Neurotensina/metabolismo , Regulação Alostérica , Sítio Alostérico , Animais , Sítios de Ligação , Análise por Conglomerados , Ligação de Hidrogênio , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ratos , Receptores de Neurotensina/agonistas , Receptores de Neurotensina/antagonistas & inibidores , Termodinâmica , Fatores de TempoRESUMO
We report a strategy of utilizing irreversible cysteine cathepsin inhibitor as trapping agent to increase the tumor residence time of receptor-targeted agents. The targeted constructs incorporating these cysteine cathepsin trapping agents were able to form high molecular weight adducts with intracellular cysteine cathepsins, thus achieving superior retention in tumor tissues.
Assuntos
Catepsinas/antagonistas & inibidores , Inibidores de Cisteína Proteinase/farmacologia , Cisteína/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Receptores de Neurotensina/antagonistas & inibidores , Catepsinas/metabolismo , Inibidores de Cisteína Proteinase/síntese química , Inibidores de Cisteína Proteinase/química , Células HT29 , Humanos , Estrutura Molecular , Terapia de Alvo Molecular , Receptores de Neurotensina/metabolismoRESUMO
BACKGROUND/AIMS: Glioblastoma is the most common and aggressive brain tumor and carries a poor prognosis. Previously, we found that neurotensin receptor 1 (NTSR1) contributes to glioma progression, but the underlying mechanisms of NTSR1 in glioblastoma invasion remain to be clarified. The aim of this study was to investigate the molecular mechanisms of NTSR1 in glioblastoma invasion. METHODS: Cell migration and invasion were evaluated using wound-healing and transwell assays. Cell proliferation was detected using CCK-8. The expression of NTSR1, Jun, and suppressor of cytokine signaling 6 (SOCS6) was detected using western blotting. The expression of miR-494 was detected by Quantitative real-time PCR. Chromatin immunoprecipitation assay was performed to examine the interaction between Jun and miR-494 promoter. Dual-luciferase reporter assay and western blotting were performed to identify the direct regulation of SOCS6 by miR-494. An orthotopic xenograft mouse model was conducted to assess tumor growth and invasion. RESULTS: NTSR1 knockdown attenuated the invasion of glioblastoma cells. Jun was positively regulated by NTSR1, which promoted miR-494 expression through binding to miR-494 promoter. SOCS6 was confirmed as a direct target of miR-494, thus, NTSR1-induced miR-494 upregulation resulted in SOCS6 downregulation. Both miR-494 and SOCS6 were involved in the NTSR1-induced invasion of glioblastoma cells. In vivo, tumor invasion and growth were inhibited by NTSR1 knockdown, but were restored with miR-494 overexpression. CONCLUSION: NTSR1 knockdown inhibited glioblastoma invasion via the Jun/miR-494/SOCS6 axis.
Assuntos
MAP Quinase Quinase 4/metabolismo , MicroRNAs/metabolismo , Receptores de Neurotensina/metabolismo , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Regiões 3' não Traduzidas , Animais , Antagomirs/metabolismo , Encéfalo/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Movimento Celular , Glioblastoma/diagnóstico por imagem , Glioblastoma/tratamento farmacológico , Glioblastoma/patologia , Humanos , MAP Quinase Quinase 4/genética , Imageamento por Ressonância Magnética , Camundongos , Camundongos Nus , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Regiões Promotoras Genéticas , Interferência de RNA , RNA Interferente Pequeno/metabolismo , RNA Interferente Pequeno/uso terapêutico , Receptores de Neurotensina/antagonistas & inibidores , Receptores de Neurotensina/genética , Proteínas Supressoras da Sinalização de Citocina/química , Proteínas Supressoras da Sinalização de Citocina/genéticaRESUMO
Several studies have suggested that neurotensin receptors (NTRs) and neurotensin (NT) greatly affect the growth and survival of pancreatic ductal adenocarcinoma (PDAC). Developing NTR-targeted PET probes could therefore be important for the management of a pancreatic cancer patient by providing key information on the NTR expression profile noninvasively. Despite the initial success on the synthesis of 18F-labeled NT PET probes, the labeling procedure generally requires lengthy steps including azeotropic drying of 18F. Using a straightforward chelation method, here we report the simple preparation of aluminum-18F-NOTA-NT starting from aqueous 18F. The cell binding test demonstrated that [19F]AlF-NOTA-NT maintained high receptor-binding affinity to NTR1. This probe was then further evaluated in NTR1 positive pancreatic tumor models (AsPC-1 and PANC-1). After the administration of [18F]AlF-NOTA-NT, small animal PET studies showed a high contrast between tumor and background in both models at 1 and 4 h time points. A blocking experiment was performed to demonstrate the receptor specificity: the tumor uptake in AsPC1 without and with blocking agent was 1.0 ± 0.2 and 0.1 ± 0.0%ID/g, respectively, at 4 h post injection. In summary, a NTR specific PET agent, [18F]AlF-NOTA-NT, was prepared through the simple chelation method. This NTR-targeted PET probe may not only be used to detect NTR1 positive pancreatic tumors (diagnosis), but also it may be fully integrated to NTR target therapy leading to personalized medicine (theranostic).
Assuntos
Carcinoma Ductal Pancreático/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico , Compostos Radiofarmacêuticos/administração & dosagem , Receptores de Neurotensina/metabolismo , Alumínio/administração & dosagem , Alumínio/química , Animais , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Flúor/administração & dosagem , Flúor/química , Radioisótopos de Flúor/administração & dosagem , Radioisótopos de Flúor/química , Compostos Heterocíclicos com 1 Anel/administração & dosagem , Compostos Heterocíclicos com 1 Anel/química , Humanos , Camundongos , Camundongos Nus , Imagem Molecular/métodos , Terapia de Alvo Molecular/métodos , Neurotensina/administração & dosagem , Neurotensina/química , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/terapia , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/química , Receptores de Neurotensina/antagonistas & inibidores , Nanomedicina Teranóstica/métodos , Microtomografia por Raio-X/métodos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Neurotensin receptor 1 (NTR1) is overexpressed in ductal pancreatic adenocarcinoma, which is still one of the deadliest cancers, with a very poor prognosis. Eligible patients were offered salvage radiopharmaceutical therapy with the novel NTR1 antagonist 177Lu-3BP-227. Methods: Six patients with confirmed ductal pancreatic adenocarcinoma who had exhausted all other treatment options received 177Lu-3BP-227 for evaluation of NTR1 expression in vivo. Three patients received treatment activities of 5.1-7.5 GBq. Results: Administration of 177Lu-3BP-227 was well tolerated by all patients. The kidneys were identified as the dose-limiting organ. The most severe adverse event was reversible grade 2 anemia. One patient achieved a partial response and experienced significant improvement of symptoms and quality of life. This patient survived 13 mo from diagnosis and 11 mo from the start of 177Lu-3BP-227 therapy. Conclusion: This initial report provides clinical evidence of the feasibility of treatment of ductal pancreatic adenocarcinoma using 177Lu-3BP-227.
Assuntos
Adenocarcinoma/terapia , Carcinoma Ductal Pancreático/terapia , Lutécio/farmacologia , Neoplasias Pancreáticas/terapia , Receptores de Neurotensina/antagonistas & inibidores , Adenocarcinoma/metabolismo , Idoso , Carcinoma Ductal Pancreático/metabolismo , Terapia Combinada , Desenho de Fármacos , Feminino , Humanos , Injeções Intravenosas , Rim/efeitos da radiação , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Neoplasias Pancreáticas/metabolismo , Qualidade de Vida , Radiometria , Cintilografia , Compostos Radiofarmacêuticos , Estudos Retrospectivos , Terapia de Salvação , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
Background: Neurotensin is a peptide that modulates central dopamine neurotransmission and dopamine-related behaviors. Methamphetamine self-administration increases neurotensin levels in the ventral tegmental area, but the consequences for self-administration behavior have not been described. Here we test the hypothesis that antagonizing neurotensin receptors in the ventral tegmental area attenuates the acquisition of methamphetamine self-administration and methamphetamine intake. Methods: We implanted mice with an indwelling catheter in the right jugular vein and bilateral cannulae directed at the ventral tegmental area. Mice were then trained to nose-poke for i.v. infusions of methamphetamine (0.1 mg/kg/infusion) on a fixed ratio 3 schedule. Results: Mice receiving microinfusions of the neurotensin NTS1/NTS2 receptor antagonist SR142948A in the ventral tegmental area (10 ng/side) prior to the first 5 days of methamphetamine self-administration required more sessions to reach acquisition criteria. Methamphetamine intake was decreased in SR142948A-treated mice both during training and later during maintenance of self-administration. Drug seeking during extinction, cue-induced reinstatement, and progressive ratio schedules was also reduced in the SR142948A group. The effects of SR142948A were not related to changes in basal locomotor activity or methamphetamine psychomotor properties. In both SR142948A- and saline-treated mice, a strong positive correlation between methamphetamine intake and enhanced locomotor activity was observed. Conclusion: Our results suggest that neurotensin input in the ventral tegmental area during initial methamphetamine exposure contributes to the acquisition of methamphetamine self-administration and modulates later intake and methamphetamine-seeking behavior in mice. Furthermore, our results highlight the role of endogenous neurotensin in the ventral tegmental area in the reinforcing efficacy of methamphetamine, independent of its psychomotor effects.
Assuntos
Comportamento Animal/efeitos dos fármacos , Estimulantes do Sistema Nervoso Central/farmacologia , Metanfetamina/farmacologia , Neurotensina/metabolismo , Receptores de Neurotensina/antagonistas & inibidores , Área Tegmentar Ventral/efeitos dos fármacos , Área Tegmentar Ventral/metabolismo , Animais , Estimulantes do Sistema Nervoso Central/administração & dosagem , Masculino , Metanfetamina/administração & dosagem , Camundongos , Camundongos Endogâmicos DBA , AutomedicaçãoRESUMO
Chronic stress is a major cause of anxiety disorders that can be reliably modeled preclinically, providing insight into alternative therapeutic targets for this mental health illness. Neuropeptides have been targeted in the past to no avail possibly due to our lack of understanding of their role in pathological models. In this study we use a rat model of chronic stress-induced anxiety-like behaviors and hypothesized that neuropeptidergic modulation of synaptic transmission would be altered in the bed nucleus of the stria terminalis (BNST), a brain region suspected to contribute to anxiety disorders. We use brain slice neurophysiology and behavioral pharmacology to compare the role of locally released endogenous neuropeptides on synaptic transmission in the oval (ov) BNST of non-stressed (NS) or chronic unpredictably stressed (CUS) rats. We found that in NS rats, post-synaptic depolarization induced the release of vesicular neurotensin (NT) and corticotropin-releasing factor (CRF) that co-acted to increase ovBNST inhibitory synaptic transmission in 59% of recorded neurons. CUS bolstered this potentiation (100% of recorded neurons) through an enhanced contribution of NT over CRF. In contrast, locally released opioid neuropeptides decreased ovBNST excitatory synaptic transmission in all recorded neurons, regardless of stress. Consistent with CUS-induced enhanced modulatory effects of NT, blockade of ovBNST NT receptors completely abolished stress-induced anxiety-like behaviors in the elevated plus maze paradigm. The role of NT has been largely unexplored in stress and our findings highlight its potential contribution to an important behavioral consequence of chronic stress, that is, exaggerated avoidance of open space in rats.
Assuntos
Ansiedade , Comportamento Animal/fisiologia , Hormônio Liberador da Corticotropina/metabolismo , Inibição Neural/fisiologia , Neurônios/fisiologia , Neurotensina/metabolismo , Receptores de Neurotensina/antagonistas & inibidores , Núcleos Septais , Estresse Psicológico , Transmissão Sináptica/fisiologia , Animais , Ansiedade/tratamento farmacológico , Ansiedade/etiologia , Ansiedade/metabolismo , Ansiedade/fisiopatologia , Comportamento Animal/efeitos dos fármacos , Doença Crônica , Modelos Animais de Doenças , Ratos , Ratos Long-Evans , Ratos Wistar , Núcleos Septais/efeitos dos fármacos , Núcleos Septais/metabolismo , Núcleos Septais/fisiopatologia , Estresse Psicológico/complicações , Estresse Psicológico/metabolismo , Estresse Psicológico/fisiopatologiaRESUMO
Neurotensin is known to inhibit neuronal Na+ , K+ -ATPase, an effect that is rescued by nitric oxide (NO) synthase inhibition. However, whether the neurotensinergic and the nitrergic systems are independent pathways, or are mechanistically linked, remains unknown. Here, we addressed this issue and found that the administration of low affinity neurotensin receptor (NTS2) antagonist, levocabastine (50 µg/kg, i.p.) inhibited NO synthase (NOS) activity by 74 and 42% after 18 h in synaptosomal and mitochondrial fractions isolated from the Wistar rat cerebral cortex, respectively; these effects disappeared 36 h after levocabastine treatment. Intriguingly, whereas neuronal NOS protein abundance decreased (by 56%) in synaptosomes membranes, it was enhanced (by 86%) in mitochondria 18 h after levocabastine administration. Levocabastine enhanced the respiratory rate of synaptosomes in the presence of oligomycin, but it failed to alter the spare respiratory capacity; furthermore, the mitochondrial respiratory chain (MRC) complexes I-IV activities were severely diminished by levocabastine administration. The inhibition of NOS and MRC complexes activities were also observed after incubation of synaptosomes and mitochondria with levocabastine (1 µM) in vitro. These data indicate that the NTS2 antagonist levocabastine regulates NOS expression and activity at the synapse, suggesting an interrelationship between the neurotensinergic and the nitrergic systems. However, the bioenergetics effects of NTS2 activity inhibition are likely to be independent from the regulation of NO synthesis.
Assuntos
Encéfalo/efeitos dos fármacos , Antagonistas não Sedativos dos Receptores H1 da Histamina/farmacologia , Mitocôndrias/efeitos dos fármacos , Óxido Nítrico/biossíntese , Piperidinas/farmacologia , Animais , Encéfalo/metabolismo , Masculino , Óxido Nítrico Sintase/metabolismo , Ratos , Ratos Wistar , Receptores de Neurotensina/antagonistas & inibidoresRESUMO
Purpose: The high affinity receptor 1 (NTSR1) and its agonist, neurotensin (NTS), are correlated with tumor cell aggressiveness in most solid tumors. As chemoresistance and tumor aggressiveness are often related, we decided to study the role of the NTSR1 complex within platinum-based chemotherapy responses. In an ovarian model, we studied carboplatin because it is the main standard of care for ovarian cancer.Experimental Design: Experimental tumors and in vitro studies were performed using SKOV3 and A2780 cells treated with carboplatin, with or without a very specific NTSR1 antagonist, SR48692. We measured the effects of these treatments on cell apoptosis and apoptosis-related proteins, platinum accumulation in the cell and nucleus, and the expression and localization of platinum transporters. NTS and NTSR1 labeling was measured in patients with ovarian cancer.Results: SR48692 enhanced the response to carboplatin in ovarian cancer cells and experimental tumors. When SR48692 is combined with carboplatin, we noted a major improvement of platinum-induced DNA damage and cell death, as well as a decrease in tumor growth. The relationship of these results to clinical studies was made by the detection of NTS and NTSR1 in 72% and 74% of ovarian cancer, respectively. Furthermore, in a large series of high-grade ovarian cancer, NTSR1 mRNA was shown to correlate with higher stages and platinum resistance.Conclusions: This study strongly suggests that the addition of NTSR1 inhibitor in combination with platinum salt-based therapy will improve the response to the drug. Clin Cancer Res; 23(21); 6516-28. ©2017 AACR.
Assuntos
Carboplatina/administração & dosagem , Neoplasias Ovarianas/tratamento farmacológico , Pirazóis/administração & dosagem , Quinolinas/administração & dosagem , Receptores de Neurotensina/genética , Adolescente , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Pirazóis/efeitos adversos , Quinolinas/efeitos adversos , Receptores de Neurotensina/antagonistas & inibidores , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The neurotensin receptor 1 represents an important drug target involved in various diseases of the central nervous system. So far, the full exploitation of potential therapeutic activities has been compromised by the lack of compounds with favorable physicochemical and pharmacokinetic properties which efficiently penetrate the blood-brain barrier. Recent progress in the generation of stabilized variants of solubilized neurotensin receptor 1 and its subsequent purification and successful structure determination presents a solid starting point to apply the approach of fragment-based screening to extend the chemical space of known neurotensin receptor 1 ligands. In this report, surface plasmon resonance was used as primary method to screen 6369 compounds. Thereby 44 hits were identified and confirmed in competition as well as dose-response experiments. Furthermore, 4 out of 8 selected hits were validated using nuclear magnetic resonance spectroscopy as orthogonal biophysical method. Computational analysis of the compound structures, taking the known crystal structure of the endogenous peptide agonist into consideration, gave insight into the potential fragment-binding location and interactions and inspires chemistry efforts for further exploration of the fragments.
Assuntos
Descoberta de Drogas , Receptores de Neurotensina/metabolismo , Bibliotecas de Moléculas Pequenas , Simulação por Computador , Descoberta de Drogas/métodos , Avaliação Pré-Clínica de Medicamentos , Humanos , Cinética , Ligantes , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Conformação Molecular , Ligação Proteica , Estabilidade Proteica , Receptores de Neurotensina/agonistas , Receptores de Neurotensina/antagonistas & inibidores , Receptores de Neurotensina/química , Reprodutibilidade dos Testes , Fluxo de TrabalhoRESUMO
Backgroud:Glioblastoma is a kind of highly malignant and aggressive tumours in the central nervous system. Previously, we found that neurotensin (NTS) and its high-affinity receptor 1 (NTSR1) had essential roles in cell proliferation and invasiveness of glioblastoma. Unexpectedly, cell death also appeared by inhibition of NTSR1 except for cell cycle arrest. However, the mechanisms were remained to be further explored. METHODS: Cells treated with SR48692, a selective antagonist of NTSR1, or NTSR1 shRNA were stained with Annexin V-FITC/PI and the apoptosis was assessed by flow cytometry. Cytochrome c release was detected by using immunofluorescence. Mitochondrial membrane potential (MMP, ΔΨm) loss was stained by JC-1 and detected by immunofluorescence or flow cytometry. Apoptosis antibody array and microRNA microarray were performed to seek the potential regulators of NTSR1 inhibition-induced apoptosis. Interaction between let-7a-3p and Bcl-w 3'UTR was evaluated by using luciferase assay. RESULTS: SR48692 induced massive apoptosis, which was related to mitochondrial cytochrome c release and MMP loss. Knockdown of NTSR1 induced slight apoptosis and significant MMP loss. In addition, NTSR1 inhibition sensitised glioblastoma cells to actinomycin D or doxorubicin-induced apoptosis. Consistently, NTSR1 inhibition-induced mitochondrial apoptosis was accompanied by downregulation of Bcl-w and Bcl-2. Restoration of Bcl-w partly rescued NTSR1 deficiency-induced apoptosis. In addition, NTSR1 deficiency promoted higher let-7a-3p expression and inhibition let-7a-3p partly rescued NTSR1 inhibition-induced apoptosis. In addition, let-7a-3p inhibition promoted 3'UTR activities of Bcl-w and the expression of c-Myc and LIN28, which were the upstream of let-7a-3p, decreased after NTSR1 inhibition. CONCLUSIONS: NTSR1 had an important role in protecting glioblastoma from intrinsic apoptosis via c-Myc/LIN28/let-7a-3p/Bcl-w axis.