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1.
Neoplasma ; 67(6): 1204-1213, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32701359

RESUMO

The long non-coding RNA (lncRNA) RUSC1-AS1 has been reported to be dysregulated in the progression of many cancers. Also, RUSC1-AS1 had been detected to be highly expressed in laryngeal squamous cell carcinoma and breast cancer cells, suggesting that RUSC1-AS1 may be a biomarker for cancers. However, the biological role and regulatory mechanism of RUSC1-AS1 in hepatocellular carcinoma (HCC) remain unknown. In this study, we found that RUSC1-AS1 was upregulated in HCC tissues and cells, and predicted unfavorable prognosis of HCC patients. The function assays including colony formation, EdU, TUNEL assay revealed that RUSC1-AS1 facilitated HCC cell proliferation and inhibited HCC cell apoptosis. Furthermore, mechanism assays including luciferase reporter assay and RIP assay demonstrated that RUSC1-AS1 could directly bind to hsa-miR-7-5p. Besides, hsa-miR-7-5p targeted and negatively regulated NOTCH3 expression. Moreover, RUSC1-AS1 sponged hsa-miR-7-5p to upregulate NOTCH3 and to trigger the NOTCH signaling pathway. The rescue assays depicted that RUSC1-AS1 regulated HCC cell proliferation and apoptosis through modulating NOTCH signaling. In conclusion, lncRNA RUSC1-AS1 promoted the proliferation and reduced the apoptosis of HCC cells through activation of NOTCH signaling via hsa-miR-7-5p/NOTCH3 axis.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , RNA Longo não Codificante , Receptores Notch/metabolismo , Transdução de Sinais , Proteínas Adaptadoras de Transdução de Sinal , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , MicroRNAs/genética , RNA Longo não Codificante/genética , Transdução de Sinais/genética
2.
Phys Rev Lett ; 119(18): 180511, 2017 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-29219550

RESUMO

Here we report on the production and tomography of genuinely entangled Greenberger-Horne-Zeilinger states with up to ten qubits connecting to a bus resonator in a superconducting circuit, where the resonator-mediated qubit-qubit interactions are used to controllably entangle multiple qubits and to operate on different pairs of qubits in parallel. The resulting 10-qubit density matrix is probed by quantum state tomography, with a fidelity of 0.668±0.025. Our results demonstrate the largest entanglement created so far in solid-state architectures and pave the way to large-scale quantum computation.

3.
J Clin Pharm Ther ; 40(6): 689-92, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26365588

RESUMO

WHAT IS KNOWN AND OBJECTIVE: Febuxostat is recommended as an alternative drug for gouty patients with a history of allopurinol hypersensitivity or carrying the HLA-B*5801 allele. CASE SUMMARY: An 81-year-old man with the medical history of gout presented to our clinic with generalized rashes for 2 days. After taking febuxostat for 2 days, he developed generalized skin rash with high fever. Laboratory tests showed elevated liver enzymes and acute kidney injury. WHAT IS KNOWN AND OBJECTIVE: This is the first identified case of febuxostat-associated DRESS. Febuxostat should be withdrawn immediately when DRESS is observed to avoid further serious complications.


Assuntos
Síndrome de Hipersensibilidade a Medicamentos/etiologia , Eosinofilia/induzido quimicamente , Febuxostat/efeitos adversos , Idoso de 80 Anos ou mais , Febuxostat/uso terapêutico , Gota/tratamento farmacológico , Humanos , Masculino
4.
Public Health ; 127(2): 109-18, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23352122

RESUMO

OBJECTIVES: To investigate the use of tobacco in Vietnam. STUDY DESIGN: Review study. METHODS: Data were collected through a review of tobacco-related literature in Vietnam. Grey literature and web content from agencies such as the World Health Organization and the US Centers for Disease Control and Prevention were consulted. RESULTS: Tobacco smoking is still common in Vietnam, although numerous policies have been issued and implemented over the last two decades. Based on the most recent data (2010), the prevalence of smoking among adults aged >15 years was 23.8%, with a higher percentage among males (47.4%) than females (1.4%). The prevalence of smoking among students aged 13-15 was 3.8% (2007), with a similar gender pattern. The prevalence of exposure to secondhand smoke is of concern, with 73.1% and 55.9% of adults reporting exposure to secondhand smoke at home and at work or other places, respectively. Of the adult respondents, 55.5% believed that smoking may cause lung cancer, stroke and heart disease. Most students (93.4%) and adults (91.6%) had seen anti-smoking media messages. Of the students, 56.4% had seen pro-cigarette advertisements on billboards, 36.9% had seen pro-cigarette advertisements in newspapers or magazines, and 8.2% had been offered free cigarettes by tobacco company representatives. The price of cigarettes decreased by approximately 5% between 1995 and 2006, whereas gross domestic product per capita increased by more than 150%. On average, smokers smoked 13.5 cigarettes per day, and spent US$86 on cigarettes per year. Despite such high levels of tobacco exposure in Vietnam, the total tax on cigarettes remains at 45% of the retail price. Furthermore, only 29.7% of smokers had been advised to quit by a healthcare provider in the past 12 months. CONCLUSION: Strong enforcement and evidence-based regulations which rounded on MPOWER are needed to help protect current smokers and non-smokers from the devastating effects of tobacco.


Assuntos
Regulamentação Governamental , Política de Saúde , Prevenção do Hábito de Fumar , Fumar/legislação & jurisprudência , Adolescente , Adulto , Publicidade/legislação & jurisprudência , Feminino , Educação em Saúde , Humanos , Masculino , Vigilância da População , Fumar/epidemiologia , Impostos , Produtos do Tabaco/economia , Poluição por Fumaça de Tabaco/legislação & jurisprudência , Poluição por Fumaça de Tabaco/prevenção & controle , Abandono do Uso de Tabaco , Vietnã/epidemiologia
5.
Phys Rev Lett ; 108(20): 205301, 2012 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-23003151

RESUMO

The concept of valence-bond resonance plays a fundamental role in the theory of the chemical bond and is believed to lie at the heart of many-body quantum physical phenomena. Here we show direct experimental evidence of a time-resolved valence-bond quantum resonance with ultracold bosonic atoms in an optical lattice. By means of a superlattice structure we create a three-dimensional array of independent four-site plaquettes, which we can fully control and manipulate in parallel. Moreover, we show how small-scale plaquette resonating valence-bond (RVB) states with s- and d-wave symmetry can be created and characterized. We anticipate our findings to open the path towards the creation and analysis of many-body RVB states in ultracold atomic gases.

6.
Phys Rev Lett ; 107(25): 255301, 2011 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-22243087

RESUMO

We use Raman-assisted tunneling in an optical superlattice to generate large tunable effective magnetic fields for ultracold atoms. When hopping in the lattice, the accumulated phase shift by an atom is equivalent to the Aharonov-Bohm phase of a charged particle exposed to a staggered magnetic field of large magnitude, on the order of 1 flux quantum per plaquette. We study the ground state of this system and observe that the frustration induced by the magnetic field can lead to a degenerate ground state for noninteracting particles. We provide a measurement of the local phase acquired from Raman-induced tunneling, demonstrating time-reversal symmetry breaking of the underlying Hamiltonian. Furthermore, the quantum cyclotron orbit of single atoms in the lattice exposed to the magnetic field is directly revealed.

7.
Phys Rev Lett ; 106(15): 155302, 2011 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-21568570

RESUMO

We simulate numerically the dynamics of strongly correlated bosons in a two-leg ladder subject to a time-dependent energy bias between the two chains. When all atoms are initially in the leg with higher energy, we find a drastic reduction of the interchain particle transfer for slow linear sweeps, in quantitative agreement with recent experiments. This effect is preceded by a rapid broadening of the quasimomentum distribution of atoms, signaling the presence of a bath of low-energy excitations in the chains. We further investigate the scenario of quantum quenches to fixed values of the energy bias. We find that for a large enough density the momentum distribution relaxes to that of an equilibrium thermal state with the same energy.

9.
AJNR Am J Neuroradiol ; 41(2): 213-218, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31974080

RESUMO

BACKGROUND AND PURPOSE: Noncontrast head CTs are routinely acquired for patients with neurologic symptoms in the emergency department setting. Anecdotally, noncontrast head CTs performed in patients with prior negative findings with the same clinical indication are of low diagnostic yield. We hypothesized that the rate of acute findings in noncontrast head CTs performed in patients with a preceding study with negative findings would be lower compared with patients being imaged for the first time. MATERIALS AND METHODS: We retrospectively evaluated patients in the emergency department setting who underwent noncontrast head CTs at our institution during a 4-year period, recording whether the patient had undergone a prior noncontrast head CT, the clinical indication for the examination, and the examination outcome. Positive findings on examinations were defined as those that showed any intracranial abnormality that would necessitate a change in acute management, such as acute hemorrhage, hydrocephalus, herniation, or interval worsening of a prior finding. RESULTS: During the study period, 8160 patients in the emergency department setting underwent a total of 9593 noncontrast head CTs; 88.2% (7198/8160) had a single examination, and 11.8% (962/8160) had at least 1 repeat examination. The baseline positive rate of the "nonrepeat" group was 4.3% (308/7198). The 911 patients in the "repeat" group with negative findings on a baseline/first CT had a total of 1359 repeat noncontrast head CTs during the study period. The rate of positive findings for these repeat examinations was 1.8% (25/1359), significantly lower than the 4.3% baseline rate (P < .001). Of the repeat examinations that had positive findings, 80% (20/25) had a study indication that was discordant with that of the prior examination, compared with only 44% (593/1334) of the repeat examinations that had negative findings (P < .001). CONCLUSIONS: In a retrospective observational study based on approximately 10,000 examinations, we found that serial noncontrast head CT examinations in patients with prior negative findings with the same study indication are less likely to have positive findings compared with first-time examinations or examinations with a new indication. This finding suggests a negative predictive value of a prior noncontrast head CT examination with negative findings with the same clinical indication.


Assuntos
Cabeça/diagnóstico por imagem , Valor Preditivo dos Testes , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Serviço Hospitalar de Emergência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
10.
J Cell Biol ; 143(4): 957-71, 1998 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-9817754

RESUMO

Endocytosis-mediated recycling of plasma membrane is a critical vesicle trafficking step important in diverse biological processes. The membrane trafficking decisions and sorting events take place in a series of heterogeneous and highly dynamic organelles, the endosomes. Syntaxin 13, a recently discovered member of the syntaxin family, has been suggested to play a role in mediating endosomal trafficking. To better understand the function of syntaxin 13 we examined its intracellular distribution in nonpolarized cells. By confocal immunofluorescence and electron microscopy, syntaxin 13 is primarily found in tubular early and recycling endosomes, where it colocalizes with transferrin receptor. Additional labeling is also present in endosomal vacuoles, where it is often found in clathrin-coated membrane areas. Furthermore, anti-syntaxin 13 antibody inhibits transferrin receptor recycling in permeabilized PC12 cells. Immunoprecipitation of syntaxin 13 revealed that, in Triton X-100 extracts, syntaxin 13 is present in a complex(es) comprised of betaSNAP, VAMP 2/3, and SNAP-25. This complex(es) binds exogenously added alphaSNAP and NSF and dissociates in the presence of ATP, but not ATPgammaS. These results support a role for syntaxin 13 in membrane fusion events during the recycling of plasma membrane proteins.


Assuntos
Membrana Celular/metabolismo , Endossomos/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Transporte Vesicular , Células 3T3 , Trifosfato de Adenosina/análise , Animais , Antineoplásicos/farmacologia , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/fisiologia , Brefeldina A/farmacologia , Células CHO , Proteínas de Transporte/análise , Proteínas de Transporte/metabolismo , Membrana Celular/ultraestrutura , Cricetinae , Endossomos/ultraestrutura , Expressão Gênica/fisiologia , Rim/citologia , Ligantes , Proteínas de Membrana/análise , Proteínas de Membrana/genética , Camundongos , Microscopia Eletrônica , Proteínas Sensíveis a N-Etilmaleimida , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Nocodazol/farmacologia , Células PC12 , Inibidores da Síntese de Proteínas/farmacologia , Proteínas Qa-SNARE , Proteínas R-SNARE , RNA Mensageiro/análise , Ratos , Proteínas de Ligação a Fator Solúvel Sensível a N-Etilmaleimida , Vesículas Sinápticas/metabolismo , Vesículas Sinápticas/ultraestrutura
11.
Int J Oral Maxillofac Surg ; 48(10): 1329-1336, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30954332

RESUMO

A stable occlusion at the time of surgery is considered important for post-surgical stability after orthognathic surgery. The aim of this study was to determine whether skeletal stability after bimaxillary surgery using a surgery-first approach for skeletal class III deformity is related to the surgical occlusal contact or surgical change. Forty-two adult patients with a skeletal class III deformity corrected by Le Fort I osteotomy and bilateral sagittal split osteotomy with a surgery-first approach were studied. Dental models were set and used to measure the surgical occlusal contact, including contact distribution, contact number, and contact area. Cone beam computed tomography was used to measure the surgical change (amount and rotation) and post-surgical skeletal stability. The relationship between skeletal stability and surgical occlusal contact or surgical change was evaluated. No relationship was found between maxillary or mandibular stability and surgical occlusal contact. However, a significant relationship was found between maxillary and mandibular stability and the amount and rotation of surgical change. The results suggest that in the surgical-orthodontic correction of skeletal class III deformity with a surgery-first approach, the post-surgical skeletal stability is not related to the surgical occlusal contact but is related to the surgical change.


Assuntos
Má Oclusão Classe III de Angle , Procedimentos Cirúrgicos Ortognáticos , Adulto , Cefalometria , Seguimentos , Humanos , Mandíbula , Maxila , Osteotomia de Le Fort , Osteotomia Sagital do Ramo Mandibular
12.
Neuron ; 30(1): 161-70, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11343652

RESUMO

Changes in SNARE conformations during MgATP-dependent priming of cracked PC12 cells were probed by their altered accessibility to various inhibitors. Dominant negative soluble syntaxin and, to a much lesser extent, VAMP coil domains inhibited exocytosis more efficiently after priming. Neurotoxins and an anti-SNAP25 antibody inhibited exocytosis less effectively after priming. We propose that SNAREs partially and reversibly assemble during priming, and that the syntaxin H3 domain is prevented from fully joining the complex until the arrival of the Ca2+ trigger. Furthermore, we find that mutation of hydrophobic residues of the SNAP25 C-terminal coil that contribute to SNARE core interactions affects the maximal rate of exocytosis, while mutation of charged residues on the surface of the complex affects the apparent affinity of the coil domain for the partially assembled complex.


Assuntos
Exocitose/fisiologia , Proteínas de Membrana/metabolismo , Neurotransmissores/metabolismo , Membranas Sinápticas/metabolismo , Vesículas Sinápticas/metabolismo , Proteínas de Transporte Vesicular , Animais , Anticorpos/efeitos dos fármacos , Anticorpos/metabolismo , Toxinas Botulínicas/farmacologia , Cinética , Mutação/fisiologia , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Norepinefrina/metabolismo , Células PC12/citologia , Células PC12/efeitos dos fármacos , Células PC12/metabolismo , Estrutura Terciária de Proteína/fisiologia , Ratos , Proteínas SNARE , Proteína 25 Associada a Sinaptossoma , Toxina Tetânica/farmacologia
13.
Neuron ; 26(2): 457-64, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10839363

RESUMO

Intracellular membrane fusion is mediated by the formation of a four-helix bundle comprised of SNARE proteins. Every cell expresses a large number of SNARE proteins that are localized to particular membrane compartments, suggesting that the fidelity of vesicle trafficking might in part be determined by specific SNARE pairing. However, the promiscuity of SNARE pairing in vitro suggests that the information for membrane compartment organization is not encoded in the inherent ability of SNAREs to form complexes. Here, we show that exocytosis of norepinephrine from PC12 cells is only inhibited or rescued by specific SNAREs. The data suggest that SNARE pairing does underlie vesicle trafficking fidelity, and that specific SNARE interactions with other proteins may facilitate the correct pairing.


Assuntos
Fusão de Membrana/fisiologia , Proteínas de Membrana/fisiologia , Proteínas de Transporte Vesicular , Sequência de Aminoácidos/genética , Animais , Toxinas Botulínicas/farmacologia , Exocitose/efeitos dos fármacos , Fusão de Membrana/efeitos dos fármacos , Proteínas de Membrana/química , Proteínas de Membrana/genética , Proteínas de Membrana/farmacologia , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/fisiologia , Norepinefrina/antagonistas & inibidores , Norepinefrina/metabolismo , Células PC12/metabolismo , Fragmentos de Peptídeos/farmacologia , Proteínas Qa-SNARE , Proteínas R-SNARE , Ratos , Proteínas SNARE , Solubilidade , Especificidade por Substrato , Proteína 25 Associada a Sinaptossoma
14.
Phys Rev E ; 95(3-1): 033205, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28415201

RESUMO

Dynamics of Langmuir solitons in the presence of a background density gradient is investigated numerically, including cases with steep gradients to the extent the solitons can disintegrate. The disintegration threshold is explained by regarding the electric field part of the soliton as a point mass moving along the self-generated potential well corresponding to the density cavity. On the other hand, it is demonstrated that the Langmuir solitons are robust when the density gradient is below the threshold. During the acceleration phase toward low density regions, Langmuir solitons adjust themselves to balance the electric field pressure and the negative plasma pressure by expelling the imbalanced portion as density cavities at the sound velocity. When the density gradient is below the disintegration threshold, the electric field part of the soliton bounces back and forth within the potential well suggesting the solitons have internal structures.

15.
Oncogenesis ; 6(4): e313, 2017 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-28394354

RESUMO

Tumor cells often produce high levels of reactive oxygen species (ROS) and display an increased ROS scavenging system. However, the molecular mechanism that balances antioxidative and oxidative stress in cancer cells is unclear. Here, we determined that oncogenic multiple copies in T-cell malignancy 1 (MCT-1) activity promotes the generation of intracellular ROS and mitochondrial superoxide. Overexpression of MCT-1 suppresses p53 accumulation but elevates the manganese-dependent superoxide dismutase (MnSOD) level via the YY1-EGFR signaling cascade, which protects cells against oxidative damage. Conversely, restricting ROS generation and/or targeting YY1 in lung cancer cells effectively inhibits the EGFR-MnSOD signaling pathway and cell invasiveness induced by MCT-1. Significantly, MCT-1 overexpression in lung cancer cells promotes tumor progression, necrosis and angiogenesis, and increases the number of tumor-promoting M2 macrophages and cancer-associated fibroblasts in the microenvironment. Clinical evidence further confirms that high expression of MCT-1 is associated with an increase in YY1, EGFR and MnSOD expression, accompanied by tumor recurrence, poor overall survival and EGFR mutation status in patients with lung cancers. Together, these data indicate that the MCT-1 oncogenic pathway is implicated in oxidative metabolism and lung carcinogenesis.

18.
Int J Oral Maxillofac Surg ; 45(6): 783-6, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26811189

RESUMO

In orthognathic surgery, maxillary (CNV2) and mandibular (CNV3) divisions of the trigeminal nerve can be blocked successfully prior to surgery. In this study, it was hypothesized that regional blocks (nerve block over a particular region: bilateral CNV2 and CNV3 divisions of the trigeminal nerve) would decrease the total requirement for intraoperative anaesthetic agents and facilitate the process of hypotensive anaesthesia. Local anaesthesia containing 1/100,000 epinephrine and 10ml 0.5% levobupivacaine was injected into the planned incisions in 50 patients. Twenty-five patients (group A) underwent orthognathic surgery without regional blocks and another 25 patients (group B) underwent surgery with regional blocks. The anaesthetic protocol was the same in both groups and administered by a single anaesthesiologist. The mean arterial pressure was recorded at several points throughout the operation, as well as all the medications used. The blood loss and the amounts of medications administered were lower in group B than in group A. In patients receiving regional blocks, the amounts of fentanyl and nicardipine required were significantly lower. The use of pre-emptive anaesthesia in orthognathic surgery may reduce the overall amounts of medications required for hypotensive anaesthesia, facilitate the intraoperative control of blood pressure, and decrease intraoperative blood loss.


Assuntos
Anestesia Dentária , Pressão Sanguínea , Bupivacaína/análogos & derivados , Epinefrina/administração & dosagem , Bloqueio Nervoso/métodos , Cirurgia Ortognática , Adulto , Anestésicos , Bupivacaína/administração & dosagem , Feminino , Humanos , Levobupivacaína , Masculino , Estudos Prospectivos , Nervo Trigêmeo
19.
Int J Oral Maxillofac Surg ; 45(12): 1526-1530, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27745793

RESUMO

Sixty-three consecutive patients undergoing bimaxillary surgery between June and August 2015 were included in this study. Twenty-one patients were included in each of three study groups. In group 1, sevoflurane was the sole maintenance anaesthesia agent used; in group 2, propofol was the predominant agent, in addition to a reduced amount of sevoflurane; in group 3, patients received sevoflurane until fixation was completed, at which point it was switched to propofol. The mean intraoperative blood loss (ml) was 707.14±290.74 in group 1, 917.62±380.30 in group 2, and 750.00±331.84 in group 3; the difference between groups 1 and 2 was significant (P=0.047). The mean score for the quality of surgical field assessment was 1.32±0.44 in group 1, 2.04±0.49 in group 2, and 1.45±0.53 in group 3 (P=0.003). The postoperative nausea and vomiting (PONV) rate was 28.6% in group 1, 9.5% in group 2, and 14.3% in group 3 (P=0.343). The quality of the surgical field was significantly better in groups 1 and 3 than in group 2. The average blood loss in group 1 was also significantly less than in group 2. The PONV rates were lower than those reported in other studies.


Assuntos
Anestésicos Inalatórios , Perda Sanguínea Cirúrgica , Éteres Metílicos , Procedimentos Cirúrgicos Ortognáticos , Náusea e Vômito Pós-Operatórios/induzido quimicamente , Propofol , Anestesia , Feminino , Humanos , Masculino , Náusea e Vômito Pós-Operatórios/epidemiologia , Sevoflurano , Adulto Jovem
20.
Oncogene ; 35(10): 1225-35, 2016 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-26073081

RESUMO

The mechanisms by which some melanoma cells adapt to Serine/threonine-protein kinase B-Raf (BRAF) inhibitor therapy are incompletely understood. In the present study, we used mass spectrometry-based phosphoproteomics to determine how BRAF inhibition remodeled the signaling network of melanoma cell lines that were BRAF mutant and PTEN null. Short-term BRAF inhibition was associated with marked changes in fibronectin-based adhesion signaling that were PTEN dependent. These effects were recapitulated through BRAF siRNA knockdown and following treatment with chemotherapeutic drugs. Increased fibronectin expression was also observed in mouse xenograft models as well as specimens from melanoma patients undergoing BRAF inhibitor treatment. Analysis of a melanoma tissue microarray showed loss of PTEN expression to predict for a lower overall survival, with a trend for even lower survival being seen when loss of fibronectin was included in the analysis. Mechanistically, the induction of fibronectin limited the responses of these PTEN-null melanoma cell lines to vemurafenib, with enhanced cytotoxicity observed following the knockdown of either fibronectin or its receptor α5ß1 integrin. This in turn abrogated the cytotoxic response to BRAF inhibition via increased AKT signaling, which prevented the induction of cell death by maintaining the expression of the pro-survival protein Mcl-1. The protection conveyed by the induction of FN expression could be overcome through combined treatment with a BRAF and PI3K inhibitor.


Assuntos
Fibronectinas/metabolismo , Melanoma/patologia , PTEN Fosfo-Hidrolase/deficiência , PTEN Fosfo-Hidrolase/genética , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/genética , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Integrina alfa5beta1/metabolismo , Camundongos , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Proteômica , Proteínas Proto-Oncogênicas B-raf/deficiência , RNA Interferente Pequeno/genética , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
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