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1.
Adv Sci (Weinh) ; 11(12): e2307360, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38224220

RESUMO

Detecting exosomal markers using laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF MS) is a novel approach for examining liquid biopsies of non-small cell lung cancer (NSCLC) samples. However, LDI-TOF MS is limited by low sensitivity and poor reproducibility when analyzing intact proteins directly. In this report, gold nanoparticles/cellulose nanocrystals (AuNPs/CNC) is introduced as the matrix for direct analysis of intact proteins in NSCLC serum exosomes. AuNPs/CNC with "dual dispersion" effects dispersed and stabilized AuNPs and improved ion inhibition effects caused by protein aggregation. These features increased the signal-to-noise ratio of [M+H]+ peaks by two orders of magnitude and lowered the detection limit of intact proteins to 0.01 mg mL-1. The coefficient of variation with or without AuNPs/CNC is measured as 10.2% and 32.5%, respectively. The excellent reproducibility yielded a linear relationship (y = 15.41x - 7.983, R2 = 0.989) over the protein concentration range of 0.01 to 20 mg mL-1. Finally, AuNPs/CNC-assisted LDI-TOF MS provides clinically relevant fingerprint information of exosomal proteins in NSCLC serum, and characteristic proteins S100 calcium-binding protein A10, Urokinase plasminogen activator surface receptor, Plasma protease C1 inhibitor, Tyrosine-protein kinase Fgr and Mannose-binding lectin associated serine protease 2 represented excellent predictive biomarkers of NSCLC risk.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Exossomos , Neoplasias Pulmonares , Nanopartículas Metálicas , Humanos , Ouro/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Nanopartículas Metálicas/química , Reprodutibilidade dos Testes , Lasers
2.
Clin Chim Acta ; 554: 117757, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38184141

RESUMO

Lung cancer is a highly prevalent malignancy worldwide and the primary cause of mortality. The absence of systematic and standardized diagnostic approaches for identifying potential pulmonary nodules, early-stage cancers, and indeterminate tumors has led clinicians to consider tissue biopsy and pathological sections as the preferred method for clinical diagnosis, often regarded as the gold standard. The conventional tissue biopsy is an invasive procedure that does not adequately capture the diverse characteristics and evolving nature of tumors. Recently, the concept of 'liquid biopsy' has gained considerable attention as a promising solution. Liquid biopsy is a non-invasive approach that facilitates repeated analysis, enabling real-time monitoring of tumor recurrence, metastasis, and response to treatment. Currently, liquid biopsy includes circulating tumor cells, circulating cell-free DNA, circulating tumor DNA, circulating cell-free RNA, extracellular vesicles, and other proteins and metabolites. With rapid progress in molecular technology, liquid biopsy has emerged as a highly promising and intriguing approach, yielding compelling results. This article critically examines the significant role and potential clinical implications of liquid biopsy in the diagnosis, treatment, and prognosis of lung cancer.


Assuntos
Ácidos Nucleicos Livres , Neoplasias Pulmonares , Células Neoplásicas Circulantes , Humanos , Neoplasias Pulmonares/genética , Recidiva Local de Neoplasia , Biópsia Líquida/métodos , Ácidos Nucleicos Livres/genética , DNA de Neoplasias , Biomarcadores Tumorais/genética , Células Neoplásicas Circulantes/patologia
3.
Health Sci Rep ; 6(9): e1522, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37692791

RESUMO

Background: Lung cancer incidence and mortality remain high and are now the leading cause of cancer-related death. Lung adenocarcinoma (LUAD) is one of the main histological subtypes of lung cancer. Previous studies have shown the role of inflammation in the development of lung cancer, but the relationship between cytokines and LUAD is still unclear. To further differentiate and explore the association of cytokines with the risk of non-invasive and invasive LUAD, we studied and assessed serum cytokine levels in patients with two types of LUAD. Methods: A cohort study of 90 non-invasive LUAD and 90 invasive LUAD was retrospectively included, and the clinical characteristics were recorded in detail. The differences in the levels of 12 serum cytokines (IFN-α, IFN-γ, IL-10, IL-12P70, IL-17A, IL-1ß, IL-2, IL-4, IL-5, IL-6, IL-8, and TNF-α) between the two groups of patients with LUAD were analyzed and evaluated. And we evaluated the clinical value of cytokine differential diagnosis of invasive LUAD based on receiver operating characteristics (ROC) curves. Results: The mean age of the patients was 56.6 years, and the proportions of males and females were 38.9% and 61.1%, respectively. IFN-α, IL-1ß, IL-2, IL-6, TNF-α, IL-4, and IL-8 were significantly increased in patients with invasive LUAD compared with the non-invasive LUAD group. Further research found that smoking is an important factor, with changes in the four cytokines IL-1ß, IL-6, IL-8, and TNF-α being significantly higher in the smoking group of patients with invasive LUAD. It can be seen from the area under the curve that IL-1ß and IL-2 have a significant differential diagnosis. Conclusions: We observed differences in preoperative serum cytokine levels between patients with invasive and non-invasive LUAD, which may serve as potential serum biomarkers for clinical differential diagnosis and disease progression assessment.

4.
Infect Drug Resist ; 16: 937-947, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36814826

RESUMO

Purpose: Vitamin D, an essential nutrient and a pleiotropic steroid hormone, has been reported to be associated with the risk and severity in patients infected with Coronavirus Disease-2019 (COVID-19). The role of vitamin D in predicting clinical outcome for COVID-19 patients is unknown. Here, we aimed to determine the prognostic value of plasma 25(OH)D level in COVID-19 patients. Patients and Methods: A total of 158 patients infected with novel COVID-19 Omicron variants in Shanghai were recruited in this study and were categorized into three groups by the tertile levels of plasma 25(OH)D. Plasma 25(OH)D level was determined along with routine blood tests related to liver and renal functions in newly diagnosed COVID-19 patients at admission. The nucleic acid negative conversion time of throat swab samples was evaluated as the primary clinical outcome. The prognostic value of clinical characteristics and plasma 25(OH)D level was assessed using the Kaplan-Meier plot and Cox proportional hazards regression tests. Results: Higher level of plasma 25(OH)D level in COVID-19 patients was independently associated with shorter nucleic acid negative conversion time from COVID-19 infection (multivariate adjusted HR: 0.54, 95%CI: 0.35-0.82, P=0.004, tertile 2 vs 1; multivariate adjusted HR: 0.60, 95%CI: 0.39-0.90, P=0.014, tertile 3 vs 1). Conclusion: Plasma 25(OH)D level may serve as an independent prognostic factor in COVID-19 patient. Our findings indicate the protective roles of vitamin D supplementation in the regiment of patients with COVID-19.

5.
ACS Nano ; 16(11): 18873-18885, 2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36255141

RESUMO

Colloidally prepared core@shell nanoparticles (NPs) were converted to monodisperse high entropy alloy (HEA) NPs by annealing, including quinary, senary, and septenary phases comprised of PdCuPtNi with Co, Ir, Rh, Fe, and/or Ru. Intraparticle heterogeneity, i.e., subdomains within individual NPs with different metal distributions, was observed for NPs containing Ir and Ru, with the phase stabilities of the HEAs studied by atomistic simulations. The quinary HEA NPs were found to be durable catalysts for the oxygen reduction reaction, with all but the PdCuPtNiIr NPs presenting better activities than commercial Pt. Density functional theory (DFT) calculations for PdCuPtNiCo and PdCuPtNiIr surfaces (the two extremes in performance) found agreement with experiment by weighting the adsorption energy contributions by the probabilities of each active site based on their DFT energies. This finding highlights how intraparticle heterogeneity, which we show is likely overlooked in many systems due to analytical limitations, can be leveraged toward efficient catalysis.

6.
Small ; 18(22): e2200784, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35332677

RESUMO

Circulating microRNAs (miRNAs) can be used as noninvasive biomarkers and are also found circulating in body fluids such as blood. Dysregulated miRNA expression is associated with many diseases, including non-small cell lung cancer (NSCLC), and the miRNA assay is helpful in cancer diagnosis, prognosis, and monitoring. In this work, a versatile electrochemical biosensing system is developed for miRNA detection by DNAzyme-cleavage cycling amplification and hybridization chain reaction (HCR) amplification. With cleavage by Mn2+ targeted DNAzyme, DNA-walker can move along the predesigned DNA tracks and contribute to the transduction and enhancement of signals. For the electrochemical process, the formation of multiple G-quadruplex-incorporated long double-stranded DNA (dsDNA/G-quadruplex) structures is triggered through HCR amplification. The introduction of G-quadruplex allows sensitive measurement of miRNA down to 5.68 fM with good specificity. Furthermore, by profiling miRNA in the NSCLC cohort, this designed strategy shows high efficiency (area under the curve (AUC) of 0.879 using receiver operating characteristic (ROC) analysis) with the sensitivity of 80.0% for NSCLC early diagnosis (stage I). For the discrimination of NSCLC and benign disease, the assay displays an AUC of 0.907, superior to six clinically-acceptable protein tumor markers. Therefore, this platform holds promise in clinical application toward NSCLC diagnosis and prognosis.


Assuntos
Técnicas Biossensoriais , Carcinoma Pulmonar de Células não Pequenas , MicroRNA Circulante , DNA Catalítico , Neoplasias Pulmonares , MicroRNAs , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , DNA/química , DNA Catalítico/metabolismo , Técnicas Eletroquímicas , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , MicroRNAs/genética
7.
Nanoscale ; 13(46): 19587-19592, 2021 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-34812459

RESUMO

Lateral multiheterostructures with spatially modulated bandgaps have great potential for applications in high-performance electronic, optoelectronic and thermoelectric devices. Multiheterostructures based on transition metal tellurides are especially promising due to their tunable bandgap in a wide range and the rich variety of structural phases. However, the synthesis of telluride-based multiheterostructures remains a challenge due to the low activity of tellurium and the poor thermal stability of tellurium alloys. In this work, we synthesized monolayer WSe2-2xTe2x/WSe2-2yTe2y (x > y) multiheterostructures in situ using chemical vapor deposition (CVD). Photoluminescence analysis and Raman mapping confirm the spatial modulation of the bandgap in the radial direction. Furthermore, field-effect transistors with the channels parallel (type I) and perpendicular (type II) to the multiheterostructure rings were fabricated. Type I transistors exhibit enhanced ambipolar transport, due to the low energy bridges between the source and drain. Remarkably, the photocurrents in type I transistors are two orders of magnitude higher than those in type II transistors, which can be attributed to the fact that the photovoltaic photocurrents generated at the two heterojunctions are summed together in type I transistors, but they cancel each other in type II transistors. These multiheterostructures will provide a new platform for novel electronic/photonic devices with potential applications in broadband light sensing, highly sensitive imaging and ultrafast optoelectronic integrated circuits.

8.
Medicine (Baltimore) ; 98(32): e16825, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31393416

RESUMO

Observational studies have reported that childhood obesity is positively associated with risks of type 2 diabetes (T2D) and coronary artery disease (CAD) in adults; however, whether this association is causal is still unclear. In the present study, we conducted the 2-sample Mendelian randomization (MR) studies to investigate whether childhood obesity is causally associated with T2D and CAD in adults.Seven single-nucleotide polymorphisms (SNPs) that significantly associated with childhood obesity were used as instrumental variables. The 2-sample MR analyses were performed with the summary-level data of large-sample genome-wide association studies to evaluate the causal effects of childhood obesity on adult T2D and CAD and the levels of cardiometabolic traits.The 2-sample MR analyses suggested that each 1-unit increase in the log-odds of having childhood obesity was causally associated with an increased risk of adult T2D (odds ratio [OR] = 1.16, 95% confidential interval [CI] = 1.06-1.28; P = 1.0 × 10) and CAD (OR = 1.07, 95% CI = 1.02-1.12; P = 4.0 × 10) based on the inverse-variance weighted method. The MR analyses also suggested that childhood obesity was positively associated with the levels of adult body mass index, waist circumference, hip circumference, waist and hip ratio, log-transformed fasting glucose, log-transformed homeostatic model assessment (HOMA) of insulin resistance (%), and triglycerides. The childhood obesity was negatively associated with the adult high-density lipoprotein cholesterol level; however, there was no evidence of a causal association between childhood obesity and the levels of fasting glucose, 2-hour glucose, HbA1c (%), log-transformed HOMA of ß-cell function (%), low-density lipoprotein cholesterol, or total cholesterol in adults.In conclusion, a genetic predisposition to childhood obesity was associated with an increased risk of adult T2D and CAD, providing causal relations between childhood obesity and the risks of T2D and CAD in adults; however, the results need to be validated with larger-scale intervention studies.


Assuntos
Doença da Artéria Coronariana/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Obesidade Pediátrica/epidemiologia , Obesidade Pediátrica/genética , Glicemia , Índice de Massa Corporal , Pesos e Medidas Corporais , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Resistência à Insulina , Lipídeos/sangue , Masculino , Polimorfismo de Nucleotídeo Único , Fatores de Risco
9.
J Clin Lab Anal ; 33(2): e22658, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30152095

RESUMO

BACKGROUND: Monoclonal free light chains (FLC) commonly exist in monomeric or dimeric forms but rarely as larger molecules. Little is known about whether polymeric molecules can affect urine protein electrophoresis (UPE) results. METHODS: Urine samples were collected from 72 multiple myeloma (MM) patients with Bence Jones protein (BJP). Urine protein and immunofixation electrophoresis were analyzed on Sebia SDS "agarose" gel electrophoresis system (SDS-AGE), and immunoglobulin free light chains were measured on the BNII nephelometric assay. RESULTS: A type of disulfide-bound FLC dimer shows a pattern shift to the position of the "albumin" band in urine protein electrophoresis in multiple myeloma (MM) patients according to the Sebia agarose gel-based detection system, which was validated by immunofixation, SDS-PAGE, and mass spectrometric methods. Similar cases were found in 21 (29.17%) of 72 MM patients with BJP, and 19 (90.5%) of 21 patients were the lambda type. CONCLUSIONS: These results indicate that BJP with lambda type has a strong tendency to abnormally migrate, which may increase the risk of misinterpretation of protein electrophoresis in clinics. Thus, when the urine protein electrophoresis is inconsistent with the result by nephelometric method, urine protein electrophoresis needs to be repeated on the deduced condition to confirm the essence of the originally identified "albumin."


Assuntos
Proteína de Bence Jones/química , Eletroforese em Gel de Poliacrilamida/métodos , Imunoeletroforese/métodos , Cadeias Leves de Imunoglobulina/química , Mieloma Múltiplo/urina , Proteinúria/urina , Idoso , Proteína de Bence Jones/urina , Estudos de Coortes , Dissulfetos/química , Feminino , Humanos , Cadeias Leves de Imunoglobulina/urina , Masculino , Pessoa de Meia-Idade
10.
Int J Mol Med ; 43(1): 155-166, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30365064

RESUMO

Congenital hypopituitarism (CH) is a relatively rare disease that is characterized by the deficiency of one or more hormones secreted by the pituitary gland, which leads to metabolic disorders, amenorrhea and infertility. However, the underlying molecular mechanisms of CH have not yet been fully elucidated. The present study evaluated the genome­wide methylation level of whole blood DNA in 12 patients with CH and 12 age­matched controls using Illumina Human Methylation 450 array, in order to determine the roles of epigenetic regulation in the pathogenesis of CH. The results demonstrated that the methylation levels of 51 CpG sites were significantly different between the patients with CH and the controls. Functional enrichment analysis identified that the aberrant methylated genes were enriched in gene sets associated with metabolic or cellular process, immune system process and reproduction. In addition, two CpG sites on genes LIM domain kinase 2 (LIMK2) and piwi­like RNA­mediated gene silencing 2 (PIWIL2), which are involved in spermatogenesis and/or testicular development, were identified to be hypermethylated in male patients with CH. The hypermethylation of these sites was further validated in another 40 patients with CH and 40 matched controls with a quantitative bisulfite pyrosequencing method, and the methylation levels of these two loci demonstrated promising diagnostic capacities for CH. The present results suggested that aberrant methylation of genes may be involved in the pathogenesis of CH, and hypermethylation of LIMK2 and PIWIL2 may contribute to the infertility of male patients with CH. Further studies are required to elucidate the underlying mechanisms of the epigenetic regulation of these genes.


Assuntos
Células Sanguíneas/metabolismo , Metilação de DNA/genética , DNA/sangue , Estudo de Associação Genômica Ampla , Hipopituitarismo/sangue , Hipopituitarismo/genética , Adulto , Estudos de Casos e Controles , Análise por Conglomerados , Ilhas de CpG/genética , DNA/genética , Genoma Humano , Humanos , Hipopituitarismo/diagnóstico , Masculino , Curva ROC , Adulto Jovem
11.
Mol Med Rep ; 18(1): 1037-1042, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29845242

RESUMO

Spinocerebellar ataxia (SCA) is a group of genetic diseases of the nervous system with genetic and clinical heterogeneity. SCA is often caused by an expanded CAG repeat sequence in the encoding protein. Genetic testing is necessary to diagnose and classify the types of SCA. Next­generation DNA sequencing usually generates a high error rate for insertion or deletion mutations, so it is unhelpful for classifying the types of SCA. In the present study, a Chinese SCA pedigree was preliminarily diagnosed with SCA1 using polymerase chain reaction (PCR) amplification. The propositus and his three younger siblings were diagnosed with SCA1 as a result of the identification of the length of the expanded CAG repeat sequence in the ATXN1 gene performed using Sanger sequencing. The current study presents a convenient and efficient method to identify causative mutations for polyglutamine SCA using PCR amplification followed by Sanger sequencing.


Assuntos
Peptídeos/genética , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Ataxias Espinocerebelares , Expansão das Repetições de Trinucleotídeos , Adulto , Feminino , Humanos , Masculino , Ataxias Espinocerebelares/diagnóstico , Ataxias Espinocerebelares/genética
12.
Int J Oncol ; 51(2): 489-497, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28656243

RESUMO

PTPRA is reported to be involved in cancer development and progression through activating the Src family kinase (SFK) signaling pathways, however, the roles of PTPRA in the squamous cell lung cancer (SCC) development are unclear. The purpose of this study was to clarify the clinical relevance and biological roles of PTPRA in SCC. We found that PTPRA was upregulated in squamous cell lung cancer compared to matched normal tissues at the mRNA (N=20, P=0.004) and protein expression levels (N=75, P<0.001). Notably, high mRNA level of PTPRA was significantly correlated with poorer prognosis in 675 SCC patients from the Kaplan-Meier plotter database. With 75 cases, we found that PTPRA protein expression was significantly correlated with tumor size (P=0.002), lymph node metastasis (P=0.008), depth of tumor invasion (P<0.001) and clinical stage (P<0.001). The Kaplan-Meier plot suggested that high expression of PTPRA had poorer overall survival in SCC patients (P=0.009). Multivariate Cox regression analysis suggested that PTPRA expression was an independent prognostic factor in SCC patients. In the cellular models, PTPRA promotes SCC cell proliferation through modulating Src activation as well as cell cycle progression. In conclusion, higher PTPRA level was associated with worse prognosis of SCC patients and PTPRA could promote the cell cycle progression through stimulating the c-Src signaling pathways.


Assuntos
Neoplasias Pulmonares/genética , Neoplasias de Células Escamosas/genética , Proteínas Tirosina Fosfatases Classe 4 Semelhantes a Receptores/genética , Quinases da Família src/genética , Idoso , Proteína Tirosina Quinase CSK , Linhagem Celular Tumoral , Intervalo Livre de Doença , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/patologia , Metástase Linfática/genética , Metástase Linfática/patologia , Masculino , Pessoa de Meia-Idade , Neoplasias de Células Escamosas/epidemiologia , Neoplasias de Células Escamosas/patologia , Prognóstico , RNA Mensageiro/genética , Transdução de Sinais
13.
Cell Signal ; 37: 62-73, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28583374

RESUMO

Here, bioinformatics data from Sirt1 knock-out (KO) and knock-in (KI) mice suggest that Sirt1 inhibits Wnt/ßCatenin signaling in the liver. However, it is unclear how this relationship occurs and how it contributes to malignant phenotypes in liver cancer cells. We found that Sirt1 expression promotes phosphorylation of ßCatenin at Ser675, which may subsequently decrease expression of total-ßCatenin. Mechanistically, Sirt1 expression elevates phosphorylation of the alpha subunit of protein kinase A (PKAα), and this event is essential for Sirt1-induced phosphorylation of ßCatenin. The negative effects of Sirt1 on ßCatenin stability are also dependent on PKAα. Stimulating PKAα recruits ßTrCP, a well-known ubiquitin E3 ligase for ßCatenin, to ßCatenin. Interestingly, Sirt1 expression is able to up-regulate ßTrCP expression. Finally, we found that malignant phenotypes occur in hepatocytes when Sirt1 and ßCatenin are co-overexpressed, and such effects are enhanced by simultaneous knockdown of PKAα. In contrast, malignant phenotypes are abrogated upon knockdown of Sirt1, and this phenotype is magnified by knockdown of ßCatenin. Collectively, we conclude that suppression of both Sirt1 and Wnt/ßCatenin might be effective in treating liver cancer.


Assuntos
Subunidades Catalíticas da Proteína Quinase Dependente de AMP Cíclico/metabolismo , Neoplasias Hepáticas/metabolismo , Sirtuína 1/metabolismo , Via de Sinalização Wnt , Animais , Linhagem Celular Tumoral , Subunidades Catalíticas da Proteína Quinase Dependente de AMP Cíclico/genética , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Hepáticas/genética , Camundongos Endogâmicos C57BL , Fosforilação , Mapas de Interação de Proteínas , Estabilidade Proteica , Sirtuína 1/genética , Ubiquitinação , beta Catenina/metabolismo
14.
Mol Med Rep ; 11(6): 4303-8, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25625869

RESUMO

Protein tyrosine phosphatase (PTP)­α regulates the phosphorylation of focal adhesion kinase (FAK), which is important in cellular signal transduction and integration of proteins. It has been demonstrated that a FAK­Del33 mutation (deletion of exon 33; KF437463) in breast cancer tissues regulates cell migration through FAK/Src signaling activation. However, the detailed pathway for Src activation with FAK­Del33 remains to be elucidated. The present study used a retroviral expression system to examine changes in PTPα phosphorylation affected by the FAK­Del33 protein in breast cancer cells. Small interfering (si)RNA targeting PTPα interfered with the phosphorylation of Src. Wound­healing and migration assays were performed to identify cell morphology and quantitative analysis was performed by examining band color depth in western blot analysis. Significant differences were observed in the phosphorylation level of PTPα at Tyr789 between the FAK­Del33 and the wild­type breast cancer cells, suggesting that FAK regulated the phosphorylation level of PTPα at Tyr789 in breast cancer mutant FAK­Del33 cells. The gene expression profile with FAK siRNA did not alter the levels of phosphorylation in other mutants, including autophosphorylation disability (Y397F), ATP kinase dominant negative (K454R) and protein 4.1, ezrin, radixin, moesin domain attenuate (Δ375). FAK RNAi inhibited the activity of the FAK­Del33 at the Src site and rescued the elevated cell migration and invasion. The present study demonstrated for the first time, to the best of our knowledge, an increase in the phosphorylation level of PTPα­Tyr789 by its upstream activator, FAK­Del33, leading to Src activation in certain breast cancer cells, which has significant implications for metastatic potential.


Assuntos
Neoplasias da Mama/metabolismo , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Proteínas Tirosina Fosfatases Classe 4 Semelhantes a Receptores/metabolismo , Substituição de Aminoácidos , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Movimento Celular , Feminino , Proteína-Tirosina Quinases de Adesão Focal/genética , Humanos , Fosforilação , Interferência de RNA , Deleção de Sequência , Cicatrização
15.
PLoS One ; 9(9): e107134, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25226367

RESUMO

Mounting evidence suggests that the FAK N-terminal (FERM) domain controls FAK phosphorylation and function; however, little is known regarding the role of the C terminal (FAT) domain in FAK regulation. We identified a patient-derived FAK mutant, in which a 27-amino acid segment was deleted from the C-terminal FAT domain (named FAK-Del33). When FAK-Del33 was overexpressed in specific tumor cell lines, Y397 phosphorylation increased compared with that observed in cells expressing FAK-WT. Here, we attempt to unveil the mechanism of this increased phosphorylation. Using cell biology experiments, we show that FAK-Del33 is incapable of co-localizing with paxillin, and has constitutively high Y397 phosphorylation. With a kinase-dead mutation, it showed phosphorylation of FAK-Del33 has enhanced through auto-phosphorylation. It was also demonstrated that phosphorylation of FAK-Del33 is not Src dependent or enhanced intermolecular interactions, and that the hyperphosphorylation can be lowered using increasing amounts of transfected FERM domain. This result suggests that Del33 mutation disrupting of FAT's structural integrity and paxillin binding capacity leads to incapable of targeting Focal adhesions, but has gained the capacity for auto-phosphorylation in cis.


Assuntos
Proteína-Tirosina Quinases de Adesão Focal/genética , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Mutação , Domínios e Motivos de Interação entre Proteínas/genética , Sequência de Aminoácidos , Animais , Adesão Celular , Linhagem Celular Transformada , Linhagem Celular Tumoral , Proteína-Tirosina Quinases de Adesão Focal/química , Humanos , Dados de Sequência Molecular , Paxilina/metabolismo , Fosforilação , Ligação Proteica , Estrutura Secundária de Proteína , Transporte Proteico , Alinhamento de Sequência , Quinases da Família src/metabolismo
16.
Nat Commun ; 5: 3640, 2014 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-24784991

RESUMO

Increasing the conversion efficiency of thermoelectric materials is a key scientific driver behind a worldwide effort to enable heat to electricity power generation at competitive cost. Here we report an increased performance for antimony-doped lead selenide with a thermoelectric figure of merit of ~1.5 at 800 K. This is in sharp contrast to bismuth doped lead selenide, which reaches a figure of merit of <1. Substituting antimony or bismuth for lead achieves maximum power factors between ~23-27 µW cm(-1) K(-2) at temperatures above 400 K. The addition of small amounts (~0.25 mol%) of antimony generates extensive nanoscale precipitates, whereas comparable amounts of bismuth results in very few or no precipitates. The antimony-rich precipitates are endotaxial in lead selenide, and appear remarkably effective in reducing the lattice thermal conductivity. The corresponding bismuth-containing samples exhibit smaller reduction in lattice thermal conductivity.

17.
J Am Chem Soc ; 136(4): 1628-35, 2014 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-24397485

RESUMO

We examine the thermodynamics of phase separation and ordering in the ternary Ca(x)Pb(1-x)S and Sr(x)Pb(1-x)S systems by density-functional theory combined with a cluster expansion and Monte Carlo simulations. Similar to most other ternary III-V or IV-VI semiconductor alloys, we find that bulk phase separation is thermodynamically preferred for PbS-CaS. However, we predict the surprising existence of stable, ordered ternary compounds in the PbS-SrS system. These phases are previously unreported ordered rocksalt-based compounds: SrPb3S4, SrPbS2, and Sr3PbS4. The stability of these predicted ordered phases is confirmed by transmission electron microscopy observations and band gap measurements. We believe this work paves the way for a combined theory-experiment approach to decipher complex phase relations in multicomponent chalcogenide systems.

18.
Biochem Biophys Res Commun ; 443(2): 363-9, 2014 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-24360952

RESUMO

Focal adhesion kinase (FAK) regulates cell adhesion, migration, proliferation, and survival. We identified a novel splicing mutant, FAK-Del33 (exon 33 deletion, KF437463), in both breast and thyroid cancers through colony sequencing. Considering the low proportion of mutant transcripts in samples, this mutation was detected by TaqMan-MGB probes based qPCR. In total, three in 21 paired breast tissues were identified with the FAK-Del33 mutation, and no mutations were found in the corresponding normal tissues. When introduced into a breast cell line through lentivirus infection, FAK-Del33 regulated cell motility and migration based on a wound healing assay. We demonstrated that the expression of Tyr397 (main auto-phosphorylation of FAK) was strongly increased in FAK-Del33 overexpressed breast tumor cells compared to wild-type following FAK/Src RTK signaling activation. These results suggest a novel and unique role of the FAK-Del33 mutation in FAK/Src signaling in breast cancer with significant implications for metastatic potential.


Assuntos
Neoplasias da Mama/enzimologia , Neoplasias da Mama/genética , Análise Mutacional de DNA , Éxons/genética , Proteína-Tirosina Quinases de Adesão Focal/genética , Mutação/genética , Feminino , Deleção de Genes , Humanos , Células Tumorais Cultivadas
19.
PLoS One ; 7(12): e50502, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23251372

RESUMO

DRAM is a lysosomal membrane protein and is critical for p53-mediated autophagy and apoptosis. DRAM has a potential tumor-suppressive function and is downregulated in many human cancers. However, the regulation of DRAM expression is poorly described so far. Here, we demonstrated that serum deprivation strongly induces DRAM expression in liver cancer cells and a core DNA sequence in the DRAM promoter is essential for its responsiveness to serum deprivation. We further observed that euchromatin markers for active transcriptions represented by diacetyl-H3, tetra-acetyl-H4 and the trimethyl-H3K4 at the core promoter region of DRAM gene are apparently increased in a time-dependent manner upon serum deprivation, and concomitantly the dimethyl-H3K9, a herterochromatin marker associated with silenced genes, was time-dependently decreased. Moreover, the chromatin remodeling factor Brg-1 is enriched at the core promoter region of the DRAM gene and is required for serum deprivation induced DRAM expression. These observations lay the ground for further investigation of the DRAM gene expression.


Assuntos
Carcinoma Hepatocelular/genética , Histonas/genética , Neoplasias Hepáticas/genética , Proteínas de Membrana/genética , Regiões Promotoras Genéticas , Apoptose/genética , Autofagia/genética , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Histonas/metabolismo , Humanos , Neoplasias Hepáticas/metabolismo , Proteínas de Membrana/metabolismo , NF-kappa B/genética , NF-kappa B/metabolismo
20.
Nucleic Acids Res ; 39(15): 6440-55, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21572107

RESUMO

CD166/ALCAM plays an important role in tumor aggression and progression as well as protecting cancer cells against apoptosis and autophagy. However, the mechanism by which pro-cell death signals control CD166 expression remains unclear. Here we show that following serum deprivation (SD), upregulation of CD166 protein is shorter than that of CD166 mRNA. Molecular analysis revealed both CD166 and miR-9-1 as two novel NF-κB target genes in hepatoma cells. In vivo activation and translocation of the NF-κB P50/P65 hetero-dimer into the nucleus following the phosphorylation and accompanied degradation of its inhibitor, IκBα, contributes to efficient transcription of both genes following SD. We show that following serum starvation, delayed up-regulation of miR-9 represses translation of CD166 protein through its target sites in the 3'-UTR of CD166 mRNA. We also propose that miR-9 promotes cell migration largely due to inhibition of CD166. Collectively, the study elucidates a novel negative auto-regulatory loop in which NF-κB mediates differential regulation of CD166 after SD.


Assuntos
Molécula de Adesão de Leucócito Ativado/genética , Regulação da Expressão Gênica , MicroRNAs/metabolismo , Subunidade p50 de NF-kappa B/metabolismo , Fator de Transcrição RelA/metabolismo , Molécula de Adesão de Leucócito Ativado/biossíntese , Linhagem Celular Tumoral , Movimento Celular , Meios de Cultura Livres de Soro , Dimerização , Elementos Facilitadores Genéticos , Retroalimentação Fisiológica , Humanos , MicroRNAs/genética , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , Regulação para Cima
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