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1.
Comput Biol Med ; 168: 107774, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38039897

RESUMO

Neural architecture search (NAS) has been introduced into the design of deep neural network architectures for Magnetic Resonance Imaging (MRI) reconstruction since NAS-based methods can acquire the complex network architecture automatically without professional designing experience and improve the model's generalization ability. However, current NAS-based MRI reconstruction methods suffer from a lack of efficient operators in the search space, which leads to challenges in effectively recovering high-frequency details. This limitation is primarily due to the prevalent use of convolution operators in the current search space, which struggle to capture both global and local features of MR images simultaneously, resulting in insufficient information utilization. To address this issue, a generative adversarial network (GAN) based model is proposed to reconstruct the MR image from under-sampled K-space data. Firstly, parameterized global and local feature learning modules at multiple scales are added into the search space to improve the capability of recovering high-frequency details. Secondly, to mitigate the increased search time caused by the augmented search space, a hierarchical NAS is designed to learn the global-local feature learning modules that enable the reconstruction network to learn global and local information of MR images at different scales adaptively. Thirdly, to reduce the number of network parameters and computational complexity, the standard operations in global-local feature learning modules are replaced with lightweight operations. Finally, experiments on several publicly available brain MRI image datasets evaluate the performance of the proposed method. Compared to the state-of-the-art MRI reconstruction methods, the proposed method yields better reconstruction results in terms of peak signal-to-noise ratio and structural similarity at a lower computational cost. Additionally, our reconstruction results are validated through a brain tumor classification task, affirming the practicability of the proposed method. Our code is available at https://github.com/wwHwo/HNASMRI.


Assuntos
Neoplasias Encefálicas , Processamento de Imagem Assistida por Computador , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Redes Neurais de Computação , Encéfalo/diagnóstico por imagem
2.
Front Pharmacol ; 13: 918083, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36052127

RESUMO

Preclinical pharmacokinetics (PK) and In Vitro ADME properties of GS-441524, a potential oral agent for the treatment of Covid-19, were studied. GS-441524 was stable in vitro in liver microsomes, cytosols, and hepatocytes of mice, rats, monkeys, dogs, and humans. The plasma free fractions of GS-441524 were 62-78% across all studied species. The in vitro transporter study results showed that GS-441524 was a substrate of MDR1, BCRP, CNT3, ENT1, and ENT2; but not a substrate of CNT1, CNT2, and ENT4. GS-441524 had a low to moderate plasma clearance (CLp), ranging from 4.1 mL/min/kg in dogs to 26 mL/min/kg in mice; the steady state volume distribution (Vdss) ranged from 0.9 L/kg in dogs to 2.4 L/kg in mice after IV administration. Urinary excretion appeared to be the major elimination process for GS-441524. Following oral administration, the oral bioavailability was 8.3% in monkeys, 33% in rats, 39% in mice, and 85% in dogs. The PK and ADME properties of GS-441524 support its further development as an oral drug candidate.

3.
Hum Cell ; 34(6): 1755-1764, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34324140

RESUMO

Long noncoding RNA (lncRNA) FOXC2-AS1 has been reported to act as an oncogene in multiple human cancers. However, the clinical significance, functional role and underlying mechanism of FOXC2-AS1 in gastric cancer (GC) remains largely unknown. Here, we found that FOXC2-AS1 expression was significantly elevated in GC tissues and cells, and overexpression of FOXC2-AS1 indicated advanced TNM stage and shorter overall survival in GC patients. Functionally, knockdown of FOXC2-AS1 attenuated the proliferation, migration and invasion of GC cells, whereas overexpression of FOXC2-AS1 showed the opposite effects. Further investigation revealed that FOXC2-AS1 interacted with FOXC2 mRNA and repressed its degradation. FOXC2-AS1 recruited RNA methyltransferase NSUN2 to FOXC2 mRNA, increasing its m5C level and association with YBX1. Taken together, our findings suggested that FOXC2-AS1 acted as an oncogenic lncRNA by stabilizing FOXC2 mRNA in an m5C-dependent manner, which may provide a novel therapeutic target for GC.


Assuntos
Fatores de Transcrição Forkhead , Regulação Neoplásica da Expressão Gênica/genética , Metiltransferases/metabolismo , Oncogenes , RNA Longo não Codificante , RNA Mensageiro , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Linhagem Celular , Movimento Celular/genética , Proliferação de Células/genética , Fatores de Transcrição Forkhead/metabolismo , Humanos , Terapia de Alvo Molecular , Invasividade Neoplásica/genética , Estadiamento de Neoplasias , RNA Mensageiro/metabolismo , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/terapia , Taxa de Sobrevida
4.
Int J Surg Case Rep ; 84: 106081, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34119947

RESUMO

INTRODUCTION AND IMPORTANCE: In surgery, misdiagnosis is not uncommon, usually a result of erroneous image interpretations and pathology diagnosis especially involving a tumor or cancer. Misdiagnosis may cause increased morbidity, mortality and surgical risks. CASE PRESENTATION: A 49-year-old man presented for the second time with a right upper abdominal mass of 7 months. Previous CT scan of abdomen and exploratory surgery made the diagnosis of liver cancer. Two other tertiary hospitals drew the similar conclusions. At a cancer hospital the needle biopsy was suspicious for gastrointestinal stromal tumor, Imatinib was recommended but not started due to high cost. During this re-admission, the diagnosis of liver cancer or GIST was challenged. A high risk surgery was done with successive removal of a giant tumor. A final diagnosis of paraganlioma was made and the patient is now tumor free for 6 years. CLINICAL DISCUSSION: There are 4 lessons from this case. First, a paraganlioma may be misdiagnosed. Second, the misdiagnosis may be misled by CT scan and pathology. Third, a misdiagnosis can cause increased morbidity, mortality and surgical risks. Forth, massive intraoperative hemorrhage is a high risk of surgery. CONCLUSION: Careful clinical evaluation combined with pathology diagnosis may reduce the misdiagnosis of some tumor/cancer. Surgical resection may be the only way to reach a diagnosis in patient with paraganlioma. Massive intraoperative hemorrhage is a high risk of surgery in such patients.

5.
J Mater Chem B ; 9(10): 2407-2416, 2021 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-33623935

RESUMO

Imaging-guided vascular embolization is frequently performed on patients with advanced hepatocellular carcinoma (HCC) to alleviate symptoms and extend their survival time. Current operation procedures are not only painful for patients, but are also inaccurate in tumor targeting after the release of embolic agents from the catheter, leading to injury to healthy tissues simultaneously. In this study, we developed an ultrasound-visualized, site-specific vascular embolization strategy with magnetic protein microcapsules (MPMs). MPMs were fabricated using a rapid emulsification method, giving it a smooth surface and a core-shell structure. Their diameters could be controlled within 10 µm, allowing them to pass through capillaries. The core-shell structure and loading of magnetic Fe3O4 endowed MPMs with good contrast under ultrasound imaging and magnetically inducible targeting properties, as well as aggregation response even under flowing conditions. In vitro cytotoxicity and hemolysis evaluation demonstrated good biocompatibility of the MPMs. Furthermore, mock embolization showed that cell death could be induced by aggregation of the MPMs. Such a combination of real-time monitoring using ultrasound and control on targeted vascular embolization might be a breakthrough in the treatment of advanced HCC.


Assuntos
Vasos Sanguíneos/diagnóstico por imagem , Embolização Terapêutica/métodos , Óxido Ferroso-Férrico/química , Proteínas/química , Cápsulas , Células Hep G2 , Humanos , Ultrassonografia
6.
Sci Rep ; 11(1): 2121, 2021 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-33483532

RESUMO

The spread of Plasmodium falciparum parasites resistant to most first-line antimalarials creates an imperative to enrich the drug discovery pipeline, preferably with curative compounds that can also act prophylactically. We report a phenotypic quantitative high-throughput screen (qHTS), based on concentration-response curves, which was designed to identify compounds active against Plasmodium liver and asexual blood stage parasites. Our qHTS screened over 450,000 compounds, tested across a range of 5 to 11 concentrations, for activity against Plasmodium falciparum asexual blood stages. Active compounds were then filtered for unique structures and drug-like properties and subsequently screened in a P. berghei liver stage assay to identify novel dual-active antiplasmodial chemotypes. Hits from thiadiazine and pyrimidine azepine chemotypes were subsequently prioritized for resistance selection studies, yielding distinct mutations in P. falciparum cytochrome b, a validated antimalarial drug target. The thiadiazine chemotype was subjected to an initial medicinal chemistry campaign, yielding a metabolically stable analog with sub-micromolar potency. Our qHTS methodology and resulting dataset provides a large-scale resource to investigate Plasmodium liver and asexual blood stage parasite biology and inform further research to develop novel chemotypes as causal prophylactic antimalarials.


Assuntos
Antimaláricos/farmacologia , Ensaios de Triagem em Larga Escala/métodos , Fígado/efeitos dos fármacos , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Antimaláricos/química , Avaliação Pré-Clínica de Medicamentos/métodos , Células Hep G2 , Humanos , Fígado/parasitologia , Malária Falciparum/sangue , Malária Falciparum/parasitologia , Estrutura Molecular , Testes de Sensibilidade Parasitária , Plasmodium berghei/efeitos dos fármacos , Plasmodium berghei/fisiologia , Plasmodium falciparum/genética , Plasmodium falciparum/fisiologia , Substâncias Protetoras/química , Substâncias Protetoras/farmacologia , Reprodutibilidade dos Testes , Relação Estrutura-Atividade , Tiadiazinas/química , Tiadiazinas/farmacologia
7.
Toxicol Lett ; 338: 67-77, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33290830

RESUMO

Chemical-peptide conjugation is the molecular initiating event in skin sensitization. The OECD test guideline uses a high-performance liquid chromatography/ultraviolet (HPLC/UV) detection method to quantify chemical-peptide conjugation in a direct peptide reactivity assay (DPRA), which measures the depletion of two synthetic peptides containing lysine or cysteine residues. To improve assay throughput, sensitivity and accuracy, an automated 384-well plate-based RapidFire solid-phase extraction (SPE) system coupled with tandem mass spectrometry (MS/MS) DPRA was developed and validated in the presence of a newly designed internal standard. Compared to the HPLC/UV-based DPRA, the automated SPE-MS/MS-based DPRA improved throughput from 16 min to 10 s per sample, and substrate peptides usage was reduced from 100 mM to 5 µM. When implementing the SPE-MS/MS-based DPRA into a high-throughput platform, we found 10 compounds that depleted lysine peptide and 24 compounds that depleted cysteine peptide (including 7 unreported chemicals from 55 compounds we tested) in a concentration-response manner. The adduct formation between cysteine and cinnamic aldehyde and ethylene glycol dimethacrylate were further analyzed using high-performance liquid chromatography time-of-flight mass spectrometry (HPLC-TOF-MS) to confirm the conjugation. Overall, the automated SPE-MS/MS-based platform is an efficient, economic, and accurate way to detect skin sensitizers.


Assuntos
Alérgenos/toxicidade , Cromatografia Líquida de Alta Pressão , Dermatite Alérgica de Contato/etiologia , Ensaios de Triagem em Larga Escala , Peptídeos/química , Pele/efeitos dos fármacos , Espectrometria de Massas em Tandem , Testes de Toxicidade , Alérgenos/química , Alternativas aos Testes com Animais , Cromatografia Líquida de Alta Pressão/normas , Cisteína , Ensaios de Triagem em Larga Escala/normas , Humanos , Lisina , Padrões de Referência , Reprodutibilidade dos Testes , Medição de Risco , Espectrometria de Massas em Tandem/normas
8.
J Formos Med Assoc ; 119(1 Pt 3): 392-398, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31280909

RESUMO

BACKGROUND: There are still oral cancer patients without surgery. To improve the survival, it is necessary to know the causes of the oral cancer patients without surgery. METHODS: 23,217 patients with a newly-diagnosed oral cancer in Taiwan Cancer Registry (TCR) database between 2011 and 2015 were enrolled. Data from TCR database named "Reason for No Surgery of Primary Site" were extracted for analysis of the causes of those without surgery. Overall survival plots were presented using the Kaplan-Meier method with log-rank test. RESULTS: 3263 (14%) patients did not received surgery. Among them, there were 720 patients (group 3) without surgery although surgery was advised, 154 patients (group 2) because of poor condition or death before surgery, and 2389 patients (group 1) because of other causes. Twenty-four percent of the patients with surgery were treated one month and more after diagnosis. The 5-year overall survival rates were 68.7%, 25.2%, 9.1% and 17.3% for surgery group, group 3, 2 and 1, respectively (p < 0.001). The mean age of the patients with and without surgery were 54.8 and 59.3, respectively (p < 0.01). Female patients were commoner in group 3 (p < 0.01). The patients without surgery was commoner in the middle (15.7%) and southern (14.8%) than in Northern Taiwan (12.1%). All groups without surgery had more advanced stage and lower BMI (p < 0.01). CONCLUSION: One-sevenths of patients were not treated surgically because of refusal, poor condition, older age, low BMI, and advanced stage. It is necessary to encourage the patients to undergo surgery with shortening the diagnosis-to-treatment interval.


Assuntos
Neoplasias Bucais/mortalidade , Neoplasias Bucais/cirurgia , Recusa do Paciente ao Tratamento/estatística & dados numéricos , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco , Distribuição por Sexo , Análise de Sobrevida , Taiwan/epidemiologia , Fatores de Tempo
9.
Hum Cell ; 33(1): 131-139, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31612313

RESUMO

Increasing evidence demonstrates that long noncoding RNAs (lncRNAs) play an important role in the development and progression of human cancers. LncRNA LINC00470 has been reported to function as an oncogene in glioblastoma. Until now, the roles and underlying mechanisms of LINC00470 in the progression of hepatocellular carcinoma (HCC) remain unclear. Here, we found that LINC00470 was upregulated in HCC cells and tissues. High-level LINC00470 was significantly correlated with bigger tumor size, advanced TNM stage and poor prognosis in patients with HCC. Functional studies showed that knockdown of LINC00470 expression inhibited HCC cell proliferation and cell cycle progression, while overexpression of LINC00470 showed the opposite effects. Further investigation suggested that LINC00470 was associated with NF45/NF90 complex and increased its interaction with cyclin E1 mRNA, thus inhibiting the degradation of cyclin E1 mRNA. Additionally, knockdown of cyclin E1 in LINC00470-overexpressed cells abolished its promotive effects on HCC cell proliferation. In summary, our findings suggest that targeting LINC00470 could be a potential therapeutic approach in treating HCC patients.


Assuntos
Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Proteína do Fator Nuclear 45/genética , Proteínas do Fator Nuclear 90/genética , RNA Longo não Codificante/metabolismo , Proliferação de Células/genética , Humanos
10.
Cancer Rep (Hoboken) ; 2(2): e1154, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-32935461

RESUMO

BACKGROUND: In the past decade, trackable smart drug delivery systems have played important roles in the treatment of many diseases such as cancer because the drug carriers can be visualized through their distinct physical properties. However, it is still difficult to achieve precise drug delivery because such systems usually rely on a single imaging system. AIM: This study aimed to present a novel type of multimodality imaging-guided strategy to visualize the drug carriers of eccentric magnetic microcapsule (EMM) designed for potential treatment of hepatocellular carcinoma (HCC). METHOD AND RESULTS: The EMMs were prepared by using a three-phase microfluidic device. The as-prepared EMMs embedded with Fe3O4 nanoparticles are magnetic, with high density and acoustic impedance, allowing for visualization by magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound (US) imaging during local injection. The release of drug from these EMMs can be further controlled by an external electromagnetic field (EMF). As a proof of concept, we demonstrated the process of multimodality imaging to guide local injection and the controlled release of doxorubicin (DOX) from the EMMs in a phantom. We showed that the release rate of DOX was directly correlated to the strength of the EMF. In addition, we cocultured green fluorescent protein (GFP)-transfected HeLa cancer cells with the DOX-loaded EMMs and documented their apoptosis by DOX following the release triggered by EMF. CONCLUSION: The results suggest that these EMMs serve both as contrast agents that can be visualized by multimodality imaging techniques and as smart drug delivery systems, with great potential for precision medicine.


Assuntos
Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Imagem Multimodal/métodos , Nanopartículas/administração & dosagem , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Antibióticos Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Preparações de Ação Retardada , Liberação Controlada de Fármacos , Humanos , Imageamento por Ressonância Magnética/métodos , Magnetismo/métodos , Nanopartículas/química , Neoplasias/metabolismo , Neoplasias/patologia , Imagens de Fantasmas , Polietilenoglicóis/química
11.
Biosci Rep ; 38(6)2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30287498

RESUMO

Long noncoding RNAs (lncRNAs) play critical roles in carcinogenesis and progression, and act as important gene expression modulators. Recent evidence indicates that lncRNA neuroblastoma associated transcript 1 (NBAT1) functions as a tumor suppressor in some types of human cancers. However, its functional role in the development of gastric cancer (GC) remains unknown. The aim of this research was to investigate the clinical significance and biological functions of NBAT1 in GC. NBAT1 was found to be significantly down-regulated in GC tissue. Decreased NBAT1 expression was correlated with poor differentiation, higher tumor stage and lymph node metastasis, and poor prognosis. Functional assays showed that NBAT1 inhibited GC proliferation, migration, and invasion. NBAT1 also suppressed proliferation, migration, and capillary tube formation of human umbilical vein endothelial cells (HUVECs). Mechanistically, NBAT1 interacted with Sox9, and reduced its protein stability by promoting it from polyubiquitination and proteasome-dependent degradation. Moreover, we revealed that Sox9 could occupy the NBAT1 promoter to inactivate its transcription. The negative feedback loop of NBAT1 and Sox9 continuously enhanced the suppressive effects. In conclusion, these findings suggest that feedback regulation of NBAT1 and Sox9 served as a critical effector in GC progression.


Assuntos
Carcinogênese/genética , RNA Longo não Codificante/genética , Fatores de Transcrição SOX9/genética , Neoplasias Gástricas/genética , Biomarcadores Tumorais , Linhagem Celular Tumoral , Proliferação de Células/genética , Progressão da Doença , Transição Epitelial-Mesenquimal/genética , Retroalimentação Fisiológica , Feminino , Regulação Neoplásica da Expressão Gênica , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Pessoa de Meia-Idade , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Prognóstico , Regiões Promotoras Genéticas , Neoplasias Gástricas/patologia
12.
J Mater Chem B ; 6(13): 1920-1929, 2018 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32254358

RESUMO

Ultrasound controlled drug delivery and release has attracted increased attention for targeted delivery of drug. In this report, we present a strategy for targeted drug delivery by using ultrasound to image the location of drug carriers, as well as simultaneously controlling the release rate of drug from elastic eccentric microcapsules (EEMs), based on their mode shapes (MSs) and resonant natural frequencies (NFs). We prepared a series of EEMs with various diameters of inner spherical cavities using a microfluidic chip. The EEMs could be visualized by an ultrasound imaging system within a tissue mimic (i.e. phantom). Using theoretical modeling techniques, we investigated the effects of MSs and NFs on the resonant modes of EEMs. Guided by this modelling, we applied external ultrasonic stimuli at various levels of low frequency to regulate the release rate of Rhodamine 6G (R6G, as a model drug) from EEMs. To further demonstrate the control of drug release and evaluate the efficacy of the encapsulated drugs on cancer cells, we released an anticancer drug, doxorubicin hydrochloride (DOX), from the EEMs and tested the viability of cancer cells in vitro. The results show that this novel strategy holds great promise towards development of a controlled drug release system visualized and triggered by ultrasound.

13.
Malar J ; 16(1): 147, 2017 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-28407766

RESUMO

BACKGROUND: Blocking malaria transmission is an important step in eradicating malaria. In the field, transmission requires the production of sexual stage Plasmodium parasites, called gametocytes, which are not effectively killed by the commonly used anti-malarials allowing individuals to remain infectious after clearance of asexual parasites. METHODS: To identify new gametocytocidal compounds, a library of 45,056 compounds with diverse structures was screened using a high throughput gametocyte viability assay. The characteristics of active hits were further evaluated against asexual stage parasites in a growth inhibition assay. Their cytotoxicity were tested against mammalian cells in a cytotoxicity assay. The chemical scaffold similarity of active hits were studied using scaffold cluster analysis. RESULTS: A set of 23 compounds were identified and further confirmed for their activity against gametocytes. All the 23 confirmed compounds possess dual-activities against both gametocytes responsible for human to mosquito transmission and asexual parasites that cause the clinical symptoms. Three of these compounds were fourfold more active against gametocytes than asexual parasites. Further cheminformatic analysis revealed three sets of novel scaffolds, including highly selective 4-1H-pyrazol-5-yl piperidine analogs. CONCLUSIONS: This study revealed important new structural scaffolds that can be used as starting points for dual activity anti-malarial drug development.


Assuntos
Antimaláricos/isolamento & purificação , Antimaláricos/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Ensaios de Triagem em Larga Escala , Plasmodium falciparum/efeitos dos fármacos , Antimaláricos/química , Antimaláricos/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Células Hep G2 , Humanos , Concentração Inibidora 50 , Estrutura Molecular
14.
Bioorg Med Chem Lett ; 26(12): 2907-2911, 2016 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-27156776

RESUMO

Novel imidazo[4,5-c]quinolin-2-ones were synthesized and evaluated in asexual blood stage and late stage gametocyte assays of Plasmodium falciparum, a major causative agent of malaria. The design of these compounds is based on a recently identified lead compound from a high throughput screen. A concise synthesis was developed that allowed for generation of analogues with substitution around both the quinoline and imidazolidinone rings. Through structure-activity relationship studies, a number of potent compounds were identified that possessed excellent antimalarial activity against both the asexual and sexual stages with minimal cytotoxicity in mammalian cells. This is the first Letter describing SAR and gametocytocidal activity of imidazo[4,5-c]quinolin-2-ones, a new lead series for malaria treatment and prevention.


Assuntos
Antimaláricos/farmacologia , Imidazóis/farmacologia , Malária/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Quinolonas/farmacologia , Antimaláricos/síntese química , Antimaláricos/química , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células Hep G2 , Ensaios de Triagem em Larga Escala , Humanos , Imidazóis/síntese química , Imidazóis/química , Estrutura Molecular , Testes de Sensibilidade Parasitária , Quinolonas/síntese química , Quinolonas/química , Relação Estrutura-Atividade
15.
J Neurosci ; 36(17): 4859-75, 2016 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-27122041

RESUMO

UNLABELLED: Schizophrenia is a chronic, disabling neuropsychiatric disorder with complex genetic origins. The development of strategies for genome manipulation in rodents provides a platform for understanding the pathogenic role of genes and for testing novel therapeutic agents. Neuregulin 1 (NRG1), a critical developmental neurotrophin, is associated with schizophrenia. The NRG1 gene undergoes extensive alternative splicing and, to date, little is known about the neurobiology of a novel NRG1 isoform, NRG1-IV, which is increased in the brains of individuals with schizophrenia and associated with genetic risk variation. Here, we developed a transgenic mouse model (NRG1-IV/NSE-tTA) in which human NRG1-IV is selectively overexpressed in a neuronal specific manner. Using a combination of molecular, biochemical, electrophysiological, and behavioral analyses, we demonstrate that NRG1-IV/NSE-tTA mice exhibit abnormal behaviors relevant to schizophrenia, including impaired sensorimotor gating, discrimination memory, and social behaviors. These neurobehavioral phenotypes are accompanied by increases in cortical expression of the NRG1 receptor, ErbB4 and the downstream signaling target, PIK3-p110δ, along with disrupted dendritic development, synaptic pathology, and altered prefrontal cortical excitatory-inhibitory balance. Pharmacological inhibition of p110δ reversed sensorimotor gating and cognitive deficits. These data demonstrate a novel role for NRG1-IV in learning, memory, and neural circuit formation and a potential neurobiological mechanism for schizophrenia risk; show that deficits are pharmacologically reversible in adulthood; and further highlight p110δ as a target for antipsychotic drug development. SIGNIFICANCE STATEMENT: Schizophrenia is a disabling psychiatric disorder with neurodevelopmental origins. Genes that increase risk for schizophrenia have been identified. Understanding how these genes affect brain development and function is necessary. This work is the first report of a newly generated humanized transgenic mouse model engineered to express human NRG1-IV, an isoform of the NRG1 (Neuregulin 1) gene that is increased in the brains of patients with schizophrenia in association with genetic risk. Using behavioral neuroscience, molecular biology, electrophysiology, and pharmacology, we identify a role for NRG1-IV in learning, memory, and cognition and determine that this relates to brain excitatory-inhibitory balance and changes in ErbB4/PI3K/AKT signaling. Moreover, the study further highlights the potential of targeting the PI3K pathway for the treatment of schizophrenia.


Assuntos
Modelos Animais de Doenças , Neuregulina-1/genética , Neurofisiologia , Esquizofrenia/metabolismo , Animais , Antipsicóticos/farmacologia , Receptores ErbB/genética , Hipocampo/metabolismo , Humanos , Memória/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fosfatidilinositol 3-Quinases/metabolismo , Córtex Pré-Frontal/metabolismo , Receptor ErbB-4/genética , Esquizofrenia/tratamento farmacológico , Esquizofrenia/genética , Transdução de Sinais/fisiologia
16.
Breast Cancer Res ; 17: 59, 2015 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-25902869

RESUMO

INTRODUCTION: Breast cancer, the most common cause of cancer-related deaths worldwide among women, is a molecularly and clinically heterogeneous disease. Extensive genetic and epigenetic profiling of breast tumors has recently revealed novel putative driver genes, including p21-activated kinase (PAK)1. PAK1 is a serine/threonine kinase downstream of small GTP-binding proteins, Rac1 and Cdc42, and is an integral component of growth factor signaling networks and cellular functions fundamental to tumorigenesis. METHODS: PAK1 dysregulation (copy number gain, mRNA and protein expression) was evaluated in two cohorts of breast cancer tissues (n=980 and 1,108). A novel small molecule inhibitor, FRAX1036, and RNA interference were used to examine PAK1 loss of function and combination with docetaxel in vitro. Mechanism of action for the therapeutic combination, both cellular and molecular, was assessed via time-lapse microscopy and immunoblotting. RESULTS: We demonstrate that focal genomic amplification and overexpression of PAK1 are associated with poor clinical outcome in the luminal subtype of breast cancer (P=1.29×10(-4) and P=0.015, respectively). Given the role for PAK1 in regulating cytoskeletal organization, we hypothesized that combination of PAK1 inhibition with taxane treatment could be combined to further interfere with microtubule dynamics and cell survival. Consistent with this, administration of docetaxel with either a novel small molecule inhibitor of group I PAKs, FRAX1036, or PAK1 small interfering RNA oligonucleotides dramatically altered signaling to cytoskeletal-associated proteins, such as stathmin, and induced microtubule disorganization and cellular apoptosis. Live-cell imaging revealed that the duration of mitotic arrest mediated by docetaxel was significantly reduced in the presence of FRAX1036, and this was associated with increased kinetics of apoptosis. CONCLUSIONS: Taken together, these findings further support PAK1 as a potential target in breast cancer and suggest combination with taxanes as a viable strategy to increase anti-tumor efficacy.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Microtúbulos/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Moduladores de Tubulina/farmacologia , Quinases Ativadas por p21/antagonistas & inibidores , Apoptose/genética , Neoplasias da Mama/genética , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Variações do Número de Cópias de DNA , Docetaxel , Sinergismo Farmacológico , Feminino , Amplificação de Genes , Expressão Gênica , Humanos , Prognóstico , Transdução de Sinais/efeitos dos fármacos , Taxoides/farmacologia , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo
17.
ACS Chem Biol ; 9(11): 2603-11, 2014 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-25188650

RESUMO

Epigenetic regulation of gene expression is essential in many biological processes, and its deregulation contributes to pathology including tumor formation. We used an image-based cell assay that measures the induction of a silenced GFP-estrogen receptor reporter to identify novel classes of small molecules involved in the regulation of gene expression. Using this Locus Derepression assay, we queried 283,122 compounds by quantitative high-throughput screening evaluating compounds at multiple concentrations. After confirmation and independent validation, the Locus Derepression assay identified 19 small molecules as new actives that induce the GFP message over 2-fold. Viability assays demonstrated that 17 of these actives have anti-proliferative activity, and two of them show selectivity for cancer versus patient-matched normal cells and cause unique changes in gene expression patterns in cancer cells by altering histone marks. Hence, these compounds represent chemical tools for understanding the molecular mechanisms of epigenetic control of transcription and for modulating cell growth pathways.


Assuntos
Antineoplásicos/farmacologia , Transcrição Gênica/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais
18.
Proc Natl Acad Sci U S A ; 111(6): 2349-54, 2014 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-24469833

RESUMO

The clinical development of drug combinations is typically achieved through trial-and-error or via insight gained through a detailed molecular understanding of dysregulated signaling pathways in a specific cancer type. Unbiased small-molecule combination (matrix) screening represents a high-throughput means to explore hundreds and even thousands of drug-drug pairs for potential investigation and translation. Here, we describe a high-throughput screening platform capable of testing compounds in pairwise matrix blocks for the rapid and systematic identification of synergistic, additive, and antagonistic drug combinations. We use this platform to define potential therapeutic combinations for the activated B-cell-like subtype (ABC) of diffuse large B-cell lymphoma (DLBCL). We identify drugs with synergy, additivity, and antagonism with the Bruton's tyrosine kinase inhibitor ibrutinib, which targets the chronic active B-cell receptor signaling that characterizes ABC DLBCL. Ibrutinib interacted favorably with a wide range of compounds, including inhibitors of the PI3K-AKT-mammalian target of rapamycin signaling cascade, other B-cell receptor pathway inhibitors, Bcl-2 family inhibitors, and several components of chemotherapy that is the standard of care for DLBCL.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Linfócitos B/imunologia , Linfoma Difuso de Grandes Células B/patologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , Adenina/análogos & derivados , Linhagem Celular Tumoral , Ensaios de Triagem em Larga Escala , Humanos , Linfoma Difuso de Grandes Células B/imunologia , Fosfatidilinositol 3-Quinases/metabolismo , Piperidinas
19.
Cancer Cytopathol ; 121(9): 483-8, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23408492

RESUMO

BACKGROUND: Cytology fails to detect neoplastic cells in approximately 40% to 50% of malignant pleural effusions (PEs), which commonly accompany lung adenocarcinomas. The diagnostic accuracy of various tumor markers in lung adenocarcinoma-associated cytologically negative pleural effusions (LAC-CNPEs) has been poor. The current study attempted to maximize diagnostic efforts in distinguishing LAC-CNPEs from benign PEs. METHODS: PE samples were collected from 74 patients with lung adenocarcinoma with associated cytologically positive (41 patients) and negative (33 patients) PEs, and from 99 patients with benign conditions including tuberculosis (26 patients), pneumonia (28 patients), congestive heart failure (25 patients), and cirrhosis (20 patients). The authors evaluated the diagnostic sensitivity and optimal cutoff points for the tumor markers HER2/neu, CYFRA 21-1, and carcinoembryonic antigen (CEA) to distinguish LAC-CNPEs from benign PEs. RESULTS: Mean levels of HER2/neu, CYRFA 21-1, and CEA were found to be significantly higher in LAC-CNPEs compared with benign PEs (P = .0050, P = .0039, and P < .0001, respectively). The cutoff points for HER2/neu, CYFRA 21-1, and CEA were optimally set at 3.6 ng/mL, 60 ng/mL, and 6.0 ng/mL, respectively. Their sensitivities ranged from 12.1%, to 30.3%, to 63.6%, respectively. CEA combined with CYFRA 21-1 increased diagnostic sensitivity to 66.7%. The false-positive rates of these markers in benign PEs were 6.1%, 2.0%, and 0%, respectively. CONCLUSIONS: The combination of CEA with CYFRA 21-1 appears to provide the best differentiation between LAC-CNPEs and benign PEs to date using 2 tumor markers, and allows for the early diagnosis and early treatment of approximately two-thirds of affected patients.


Assuntos
Adenocarcinoma/diagnóstico , Biomarcadores Tumorais/metabolismo , Citodiagnóstico , Neoplasias Pulmonares/diagnóstico , Derrame Pleural Maligno/diagnóstico , Adenocarcinoma/metabolismo , Idoso , Idoso de 80 Anos ou mais , Antígenos de Neoplasias/metabolismo , Antígeno Carcinoembrionário/metabolismo , Detecção Precoce de Câncer , Feminino , Humanos , Imunoensaio , Queratina-19/metabolismo , Neoplasias Pulmonares/metabolismo , Masculino , Pessoa de Meia-Idade , Derrame Pleural Maligno/metabolismo , Prognóstico , Receptor ErbB-2/metabolismo
20.
Proc Natl Acad Sci U S A ; 109(30): 12165-70, 2012 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-22689948

RESUMO

Neuregulin 1 (NRG1) and ErbB4, critical neurodevelopmental genes, are implicated in schizophrenia, but the mediating mechanisms are unknown. Here we identify a genetically regulated, pharmacologically targetable, risk pathway associated with schizophrenia and with ErbB4 genetic variation involving increased expression of a PI3K-linked ErbB4 receptor (CYT-1) and the phosphoinositide 3-kinase subunit, p110δ (PIK3CD). In human lymphoblasts, NRG1-mediated phosphatidyl-inositol,3,4,5 triphosphate [PI(3,4,5)P3] signaling is predicted by schizophrenia-associated ErbB4 genotype and PIK3CD levels and is impaired in patients with schizophrenia. In human brain, the same ErbB4 genotype again predicts increased PIK3CD expression. Pharmacological inhibition of p110δ using the small molecule inhibitor, IC87114, blocks the effects of amphetamine in a mouse pharmacological model of psychosis and reverses schizophrenia-related phenotypes in a rat neonatal ventral hippocampal lesion model. Consistent with these antipsychotic-like properties, IC87114 increases AKT phosphorylation in brains of treated mice, implicating a mechanism of action. Finally, in two family-based genetic studies, PIK3CD shows evidence of association with schizophrenia. Our data provide insight into a mechanism of ErbB4 association with schizophrenia; reveal a previously unidentified biological and disease link between NRG1-ErbB4, p110δ, and AKT; and suggest that p110δ is a previously undescribed therapeutic target for the treatment of psychiatric disorders.


Assuntos
Adenina/análogos & derivados , Receptores ErbB/metabolismo , Neuregulina-1/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Quinazolinas/farmacologia , Esquizofrenia/genética , Esquizofrenia/metabolismo , Transdução de Sinais/fisiologia , Adenina/química , Adenina/farmacologia , Anfetamina/antagonistas & inibidores , Análise de Variância , Animais , Antipsicóticos/farmacologia , Linfócitos B , Western Blotting , Linhagem Celular Transformada , Classe I de Fosfatidilinositol 3-Quinases , Receptores ErbB/genética , Citometria de Fluxo , Estudos de Associação Genética , Humanos , Camundongos , Estrutura Molecular , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Quinazolinas/química , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Receptor ErbB-4 , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Esquizofrenia/tratamento farmacológico
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