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1.
Discov Med ; 27(150): 227-233, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31421691

RESUMO

OBJECTIVE: The aim of this study was to investigate the characteristics of nasopharyngeal carcinoma (NPC) using contrast-enhanced ultrasonography (CEUS), including the enhancement patterns and the quantitative parameters. METHODS: Having been scanned using conventional ultrasonography (US) and CEUS, every case was confirmed to be NPC under endoscopic biopsy, and no case received any anti-tumor treatment before CEUS examinations. Tumor/node/metastasis stages were determined in accordance with 2002 AJCC 6th edition. Contrast enhancement patterns and quantitative parameters were observed. RESULTS: CEUS imaging of NPC showed that the tumor signal intensity enhanced early, rapidly, and remarkably, and decreased slowly later. The patterns of enhancement included spot/linear enhancement, peripheral enhancement, and mass enhancement, and two types of time intensity curves of NPC included type I and type II. There was a significant difference between peak intensity (PI) and T stage (P<0.05), whereas time-to-peak (TP) and slope did not show significant differences with T stage (P>0.05). CONCLUSION: CEUS is feasible to be applied to the nasopharynx region. The use of CEUS makes it possible to observe vascular permeability of NPC. Our results suggest that the quantitative parameter PI of nasopharyngeal carcinoma is significantly different from T stages. Thus, PI may serve as a potential noninvasive radiological prognostic indicator for NPC.

2.
PLoS One ; 14(8): e0221638, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31442259

RESUMO

OBJECTIVE: To explore the use of Contrast-enhanced Ultrasound (CEUS) in evaluating angiogenesis in a xenograft nasopharyngeal carcinoma (NPC) model in nude mice and the evolution of CEUS parameters according to the growth of NPC. METHODS: Nude mice were divided into three groups according to experiments conducted at various times from tumor implantation (8 mice/group; group A: 4 weeks from implantation; group B:6 weeks from implantation; group C:8 weeks from implantation). CNE-2 cells were transplanted in 24 nude mice and CEUS evaluations of the tumors were performed at 4, 6 or 8 weeks from implantation. CEUS parametric perfusion images and pathological findings were recorded. R version 3.4.4 software was used to analyze the CEUS parameters and pathological findings. RESULTS: One-way anova analysis indicated statistically significant differences among the three groups with the parameters of peak intensity (PI) (p<0.001), area wash in (AWI) (p<0.001), area wash out (AWO) (p<0.001) and tumor volumes (p<0.001).Pearson correlation coefficient analysis indicated that microvessel density (MVD) was correlated with tumor volume (r = 0.644, p = 0.001), PI (r = 0.904, p<0.0001), AWI (r = 0.547, p = 0.008) and AWO (r = 0.744, P<0.0001). Tumor volume was correlated with MVD (r = 0.644, p = 0.001), PI (r = 0.625, p = 0.002), AWI (r = 0.528, p = 0.012) and AWO (r = 0.784, p<0.001). The percentage of necrosis in histological sections was correlated with the percentage of CEUS unperfused area (r = 0.446,p = 0.038). Spearman rank correlation coefficient analysis indicated that vascular endothelial growth factor (VEGF) was correlated with PI (r = 0.462, P = 0.032). Welch t test indicated PI, AWI and AWO parameters were significantly lower than that of kidneys (p<0.001, p = 0.009, p = 0.005). CONCLUSIONS: The CEUS parameters PI, AWI and AWO indirectly reflect the MVD and the tumor volume in our model of subcutaneous transplanted NPC in nude mice, providing precious information on angiogenesis and tumor growth. VEGF may play a role in promoting angiogenesis of NPC.

3.
Cell Rep ; 26(4): 884-892.e4, 2019 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-30673611

RESUMO

DNA variants in the SLC16A11 coding region were identified to be strongly associated with type 2 diabetes (T2DM) in a Mexican population. Previous studies suggested that these variants disrupt SLC16A11 function and therefore proposed to revive SLC16A11 levels or activity to achieve therapeutic benefit. However, with knockout mouse models, here we show that Slc16a11 depletion has no significant metabolic defects. Further studies demonstrate that reconstitution of the mutant, but not the wild-type Slc16a11, in the liver of knockout mice causes more triglyceride accumulation and induction of insulin resistance via upregulation of lipin 1, suggesting gaining of aberrant functions of the mutant protein that affects lipid metabolism. Our findings offer a different explanation to the function of these diabetic variants, challenging the concept of enhancing SLC16A11 function to treat T2DM. The contradictory results by our and previous studies suggest that how the SLC16A11 locus contributes to human metabolism warrants further investigation.

4.
J Cell Physiol ; 234(4): 5153-5162, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30362512

RESUMO

Overexpression of long noncoding RNA (lncRNA) H19 has been observed in various cancers, which indicates that H19 exert important roles in the progression of carcinogenesis. MiR-326 has been reported to play tumor suppressive roles in multiple tumors. Recently, the competing endogenous RNA (ceRNA) hypothesis has implied that lncRNAs might function as molecular sponges for microRNAs in various cancers. However, the roles of H19/miR-326 in human hepatocellular carcinoma (HCC) still remain unclear. The aim of our study was to determine H19/miR-326 expression in HCC cells and investigate their roles in HCC development. We found that H19 was significantly elevated and miR-326 was decreased in HCC cells including Hep3B, HepG2, MHCC-97L, SK-hep1, Hun7, SMCC-7721 compared with LO2 cells, respectively. In the subsequent experiments, we observed that inhibition of H19 can repress HCC cell growth, migration, and invasion in vitro. H19 downregulation can increase miR-326 expression in HCC cells. Meanwhile, miR-326 mimics can also inhibit HCC progression, whereas miR-326 inhibitors exhibited a reverse phenomenon by modulating H19 expression. In addition, a negative association between H19 and miR-326 was predicted and confirmed. Furthermore, the transcription factor TWIST1 has been recognized as a significant regulator in tumor progression. Here, by performing bioinformatics analysis, TWIST1 was identified as a downstream target of miR-326. The findings of our study implied that lncRNA H19 can serve as a ceRNA to sponge miR-326 and modulate TWIST1 levels in HCC pathogenesis. Taken these together, these findings indicated that H19/miR-326/TWIST1 axis was involved in HCC development and can indicate a novel HCC target.

5.
Mol Cell ; 72(2): 380-394.e7, 2018 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-30293782

RESUMO

RNA splicing is a critical mechanism by which to modify transcriptome, and its dysregulation is the underlying cause of many human diseases. It remains challenging, however, to genetically modulate a splicing event in its native context. Here, we demonstrate that a CRISPR-guided cytidine deaminase (i.e., targeted-AID mediated mutagenesis [TAM]) can efficiently modulate various forms of mRNA splicing. By converting invariant guanines to adenines at either 5' or 3' splice sites (SS), TAM induces exon skipping, activation of alternative SS, switching between mutually exclusive exons, or targeted intron retention. Conversely, TAM promotes downstream exon inclusion by mutating cytidines into thymines at the polypyrimidine tract. Applying this approach, we genetically restored the open reading frame and dystrophin function of a mutant DMD gene in patient-derived induced pluripotent stem cells (iPSCs). Thus, the CRISPR-guided cytidine deaminase provides a versatile genetic platform to modulate RNA splicing and to correct mutations associated with aberrant splicing in human diseases.


Assuntos
Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Citidina Desaminase/genética , Processamento de RNA/genética , Sequência de Aminoácidos , Animais , Linhagem Celular , Distrofina/genética , Éxons/genética , Redes Reguladoras de Genes , Células HEK293 , Humanos , Íntrons/genética , Camundongos , Fases de Leitura Aberta/genética , Sítios de Splice de RNA/genética
6.
EBioMedicine ; 37: 344-355, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30348622

RESUMO

BACKGROUND: The pharmacological activation of thermogenesis in brown adipose tissue has long been considered promising strategies to treat obesity. However, identification of safe and effective agents remains a challenge. In this study, we addressed this challenge by developing a cellular system with a fluorescence readout, and applied in a high-throughput manner to screen for FDA-approved drugs that may activate endogenous UCP1 expression in adipocytes. METHODS: We have generated a Ucp1-2A-GFP reporter mouse, in which GFP intensity serves as a surrogate of the endogenous expression level of UCP1 protein; and immortalized brown adipocytes were derived from this mouse model and applied in drug screening. Candidate drugs were further tested in mouse models either fed with normal chow or high fat diet to induce obesity. FINDINGS: By using the cellular screening platform, we identified a group of FDA-approved drugs that can upregulate UCP1 expression in brown adipocyte, including previously known UCP1 activators and new candidate drugs. Further studies focusing on a previously unreported drug-sutent, revealed that sutent treatment could increase the energy expenditure and inhibit lipid synthesis in mouse adipose and liver tissues, resulting in improved metabolism and resistance to obesity. INTERPRETATION: This study offered an easy-to-use cellular screening system for UCP1 activators, and provided a candidate list of FDA-approved drugs that can potentially treat obesity. Further study of these candidates may shed new light on the drug discovery towards obesity. FUND: National Key Research and Development Program and the Strategic Priority Research Program of the Chinese Academy of Sciences, etc. (250 words).


Assuntos
Adipócitos Marrons/metabolismo , Tecido Adiposo Marrom/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Proteína Desacopladora 1/biossíntese , Adipócitos Marrons/patologia , Tecido Adiposo Marrom/patologia , Animais , Linhagem Celular Transformada , Aprovação de Drogas , Avaliação Pré-Clínica de Medicamentos , Camundongos , Camundongos Transgênicos , Proteína Desacopladora 1/genética , Estados Unidos , United States Food and Drug Administration
7.
Stem Cell Reports ; 11(1): 22-31, 2018 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-29861165

RESUMO

Hepatocyte-like cells (HLCs) derived from human pluripotent stem cells (hPSCs) offer a promising cell resource for disease modeling and transplantation. However, differentiated HLCs exhibit an immature phenotype and comprise a heterogeneous population. Thus, a better understanding of HLC differentiation will improve the likelihood of future application. Here, by taking advantage of CRISPR-Cas9-based genome-wide screening technology and a high-throughput hPSC screening platform with a reporter readout, we identified several potential genetic regulators of HLC differentiation. By using a chemical screening approach within our platform, we also identified compounds that can further promote HLC differentiation and preserve the characteristics of in vitro cultured primary hepatocytes. Remarkably, both screenings identified histone deacetylase 3 (HDAC3) as a key regulator in hepatic differentiation. Mechanistically, HDAC3 formed a complex with liver transcriptional factors, e.g., HNF4, and co-regulated the transcriptional program during hepatic differentiation. This study highlights a broadly useful approach for studying and optimizing hPSC differentiation.


Assuntos
Diferenciação Celular , Hepatócitos/citologia , Hepatócitos/metabolismo , Histona Desacetilases/metabolismo , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Sistemas CRISPR-Cas , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Linhagem Celular , Células Cultivadas , Citometria de Fluxo , Edição de Genes , Regulação da Expressão Gênica no Desenvolvimento , Marcação de Genes , Genes Reporter , Genes abl , Fator 4 Nuclear de Hepatócito/metabolismo , Histona Desacetilases/genética , Humanos , Modelos Biológicos , Fenilenodiaminas/farmacologia
8.
Yi Chuan ; 39(3): 177-188, 2017 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-28420614

RESUMO

The emergence of genome editing tools, such as the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) system, has enabled researchers to achieve somatic and germline genomic manipulations in cell lines and model organisms. Within a couple of years, genome editing is now being rapidly developed for multiple applications and widely used in biomedical researches, including creation of disease models with desired genetic mutations, screening in a high-throughput manner for drug resistance genes, and making appropriate editions to genes in vivo for disease treatment. All these applications have been facilitating the development of precision medicine research. In this review, we describe the use of genome editing technologies for a variety of research and translational applications in the precision medicine field. We also highlight some of the existing limitations or challenges as well as future directions.


Assuntos
Edição de Genes , Medicina de Precisão/métodos , Animais , Pesquisa Biomédica , Sistemas CRISPR-Cas/genética , Humanos
9.
RNA ; 23(1): 1-5, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27742910

RESUMO

Multiplex genome engineering in vivo with CRISPR/Cas9 shows great promise as a potential therapeutic approach. The ability to incorporate multiple single guide RNA (sgRNA) cassettes together with Cas9 gene expression in one AAV vector could greatly enhance the efficiency. In a recent Method article, Mefferd and coworkers indicated that small tRNA promoters could be used to drive sgRNA expression to facilitate the construction of a more effective AAV vector. In contrast, we found that when targeting endogenous genomic loci, CRISPR/Cas9 with tRNA promoter-driven sgRNA expression showed much reduced genome editing activity, compared with significant cleavage with U6 promoter-driven sgRNA expression. Though the underlying mechanisms are still under investigation, our study suggests that the CRISPR/Cas9 system with tRNA promoter-driven sgRNA expression needs to be reevaluated before it can be used for therapeutic genome editing.


Assuntos
Exorribonucleases/genética , Edição de Genes/métodos , Regiões Promotoras Genéticas , RNA Guia/genética , RNA de Transferência/genética , Sistemas CRISPR-Cas , Expressão Gênica
12.
Nanotechnology ; 23(4): 045303, 2012 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-22222308

RESUMO

In this paper, the high performance GaN-based light-emitting diodes (LEDs) with embedded microscale air voids and an SiO(2) nanomask by metal-organic chemical vapor deposition (MOCVD) were demonstrated. Microscale air voids and an SiO(2) nanomask were clearly observed at the interface between GaN nanorods (NRs) and the overgrown GaN layer by scanning electron microscopy (SEM). From the reflectance spectra we show strong reflectance differences due to the different refractive index gradient between the GaN grown on the nanotemplate and sapphire. It can increase the light extraction efficiency due to additional light scattering. The transmission electron microscopy (TEM) images show the threading dislocations were suppressed by nanoscale epitaxial lateral overgrowth (NELOG). The LEDs with embedded microscale air voids and an SiO(2) nanomask exhibit smaller reverse-bias current and large enhancement of the light output (65% at 20 mA) compared with conventional LEDs.

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