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1.
Mol Cell ; 71(1): 73-88.e5, 2018 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-30008320

RESUMO

Interphase chromatin is organized into topologically associating domains (TADs). Within TADs, chromatin looping interactions are formed between DNA regulatory elements, but their functional importance for the establishment of the 3D genome organization and gene regulation during development is unclear. Using high-resolution Hi-C experiments, we analyze higher order 3D chromatin organization during Drosophila embryogenesis and identify active and repressive chromatin loops that are established with different kinetics and depend on distinct factors: Zelda-dependent active loops are formed before the midblastula transition between transcribed genes over long distances. Repressive loops within polycomb domains are formed after the midblastula transition between polycomb response elements by the action of GAGA factor and polycomb proteins. Perturbation of PRE function by CRISPR/Cas9 genome engineering affects polycomb domain formation and destabilizes polycomb-mediated silencing. Preventing loop formation without removal of polycomb components also decreases silencing efficiency, suggesting that chromatin architecture can play instructive roles in gene regulation during development. VIDEO ABSTRACT.


Assuntos
Cromatina/metabolismo , Proteínas de Drosophila/metabolismo , Inativação Gênica , Proteínas do Grupo Polycomb/metabolismo , Animais , Sistemas CRISPR-Cas , Cromatina/genética , Proteínas de Drosophila/genética , Drosophila melanogaster , Proteínas do Grupo Polycomb/genética
2.
Plant J ; 117(5): 1330-1343, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37996996

RESUMO

Plants and bacteria have distinct pathways to synthesize the bioactive vitamin B1 thiamin diphosphate (TDP). In plants, thiamin monophosphate (TMP) synthesized in the TDP biosynthetic pathway is first converted to thiamin by a phosphatase, which is then pyrophosphorylated to TDP. In contrast, bacteria use a TMP kinase encoded by ThiL to phosphorylate TMP to TDP directly. The Arabidopsis THIAMIN REQUIRING2 (TH2)-encoded phosphatase is involved in TDP biosynthesis. The chlorotic th2 mutants have high TMP and low thiamin and TDP. Ectopic expression of Escherichia coli ThiL and ThiL-GFP rescued the th2-3 mutant, suggesting that the bacterial TMP kinase could directly convert TMP into TDP in Arabidopsis. These results provide direct evidence that the chlorotic phenotype of th2-3 is caused by TDP rather than thiamin deficiency. Transgenic Arabidopsis harboring engineered ThiL-GFP targeting to the cytosol, chloroplast, mitochondrion, or nucleus accumulated higher TDP than the wild type (WT). Ectopic expression of E. coli ThiL driven by the UBIQUITIN (UBI) promoter or an endosperm-specific GLUTELIN1 (GT1) promoter also enhanced TDP biosynthesis in rice. The pUBI:ThiL transgenic rice accumulated more TDP and total vitamin B1 in the leaves, and the pGT1:ThiL transgenic lines had higher TDP and total vitamin B1 in the seeds than the WT. Total vitamin B1 only increased by approximately 25-30% in the polished and unpolished seeds of the pGT1:ThiL transgenic rice compared to the WT. Nevertheless, these results suggest that genetic engineering of a bacterial vitamin B1 biosynthetic gene downstream of TMP can enhance vitamin B1 production in rice.


Assuntos
Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Ectópica do Gene , Tiamina/metabolismo , Tiamina Pirofosfato/genética , Tiamina Pirofosfato/metabolismo , Tiamina Monofosfato/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Bactérias/metabolismo , Proteínas de Ligação a DNA/genética
3.
BMC Bioinformatics ; 22(Suppl 10): 634, 2022 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-36482308

RESUMO

BACKGROUND: Recent increasing evidence indicates that three-dimensional chromosome structure plays an important role in genomic function. Topologically associating domains (TADs) are self-interacting regions that have been shown to be a chromosomal structural unit. During evolution, these are conserved based on checking synteny block cross species. Are there common TAD patterns across species or cell lines? RESULTS: To address the above question, we propose a novel task-TAD recognition-as opposed to traditional TAD identification. Specifically, we treat Hi-C maps as images, thus re-casting TAD recognition as image pattern recognition, for which we use a convolutional neural network and a residual neural network. In addition, we propose an elegant way to generate non-TAD data for binary classification. We demonstrate deep learning performance which is quite promising, AUC > 0.80, through cross-species and cell-type validation. CONCLUSIONS: TADs have been shown to be conserved during evolution. Interestingly, our results confirm that the TAD recognition model is practical across species, which indicates that TADs between human and mouse show common patterns from an image classification point of view. Our approach could be a new way to identify TAD variations or patterns among Hi-C maps. For example, TADs of two Hi-C maps are conserved if the two classification models are exchangeable.


Assuntos
Aprendizado Profundo , Humanos , Animais , Camundongos , Genômica
4.
BMC Bioinformatics ; 23(1): 64, 2022 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-35144531

RESUMO

BACKGROUND: With the development of HiC technology, more and more HiC sequencing data have been produced. Although there are dozens of packages that can turn sequencing data into contact maps, there is no appropriate tool to query contact maps in order to extract biological information from HiC datasets. RESULTS: We present HiCmapTools, a tool for biologists to efficiently calculate and analyze HiC maps. The complete program provides multi-query modes and analysis tools. We have validated its utility on two real biological questions: TAD loop and TAD intra-density. CONCLUSIONS: HiCmapTools supports seven access options so that biologists can quantify contact frequency of the interest sites. The tool has been implemented in C++ and R and is freely available at https://github.com/changlabtw/hicmaptools and documented at https://hicmaptools.readthedocs.io/ .


Assuntos
Cromatina , Genômica
5.
J Cell Mol Med ; 26(15): 4305-4321, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35794816

RESUMO

Lung cancer is the leading cause of cancer-associated death, with a global 5-year survival rate <20%. Early metastasis and recurrence remain major challenges for lung cancer treatment. The stemness property of cancer cells has been suggested to play a key role in cancer plasticity, metastasis and drug-resistance, and is a potential target for drug development. In this study, we found that in non-small cell lung cancer (NSCLC), BMI1 and MCL1 play crucial roles of cancer stemness including invasion, chemo-resistance and tumour initiation. JNK signalling serves as a link between oncogenic pathway or genotoxicity to cancer stemness. The activation of JNK, either by mutant EGFR or chemotherapy agent, stabilized BMI1 and MCL1 proteins through suppressing the expression of E3-ubiquitin ligase HUWE1. In lung cancer patient samples, high level of BMI1 is correlated with poor survival, and the expression of BMI1 is positively correlated with MCL1. A novel small-molecule, BI-44, was developed, which effectively suppressed BMI1/MCL1 expressions and inhibited tumour formation and progression in preclinical models. Targeting cancer stemness mediated by BMI1/MCL1 with BI-44 provides the basis for a new therapeutic approach in NSCLC treatment.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Células-Tronco Neoplásicas/metabolismo , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
6.
Bioinformatics ; 37(11): 1506-1514, 2021 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-30726875

RESUMO

MOTIVATION: Most evolutionary analyses are based on pre-estimated multiple sequence alignment. Wong et al. established the existence of an uncertainty induced by multiple sequence alignment when reconstructing phylogenies. They were able to show that in many cases different aligners produce different phylogenies, with no simple objective criterion sufficient to distinguish among these alternatives. RESULTS: We demonstrate that incorporating MSA induced uncertainty into bootstrap sampling can significantly increase correlation between clade correctness and its corresponding bootstrap value. Our procedure involves concatenating several alternative multiple sequence alignments of the same sequences, produced using different commonly used aligners. We then draw bootstrap replicates while favoring columns of the more unique aligner among the concatenated aligners. We named this concatenation and bootstrapping method, Weighted Partial Super Bootstrap (wpSBOOT). We show on three simulated datasets of 16, 32 and 64 tips that our method improves the predictive power of bootstrap values. We also used as a benchmark an empirical collection of 853 one to one orthologous genes from seven yeast species and found wpSBOOT to significantly improve discrimination capacity between topologically correct and incorrect trees. Bootstrap values of wpSBOOT are comparable to similar readouts estimated using a single method. However, for reduced trees by 50 and 95% bootstrap thresholds, wpSBOOT comes out the lowest Type I error (less FP). AVAILABILITY AND IMPLEMENTATION: The automated generation of replicates has been implemented in the T-Coffee package, which is available as open source freeware available from www.tcoffee.org. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

7.
IUBMB Life ; 74(2): 157-169, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34467634

RESUMO

Tumor-associated macrophages (TAMs) are a major component of the tumor microenvironment (TME) and are key cells in regulating tumor development, metastasis, immune responses, inflammation, and chemoresistance. In response to TME stimulation, circulating monocytes are recruited and differentiated as TAMs. Most TAMs are defined as alternatively activated (M2) phenotype to create immunosuppressive TME and support tumor progression. In contrast, classically activated (M1) TAMs can produce pro-inflammatory cytokines and enhance immune responses against tumor development. Autophagy is a conserved catabolic process to control cellular homeostasis and biological function. Emerging evidence reveals crucial contribution of autophagy in modulating TAM plasticity and functional polarization in TME. In this review, we introduce the current understanding of autophagy-regulated TAM function in development of cancer. We focus on how autophagy modulates antigen presentation, LC3-associated phagocytosis, cytokine secretion, inflammasome regulation, recruitment, differentiation, and polarization of TAMs and suggest strategies for potential therapeutics by targeting autophagy in TAMs. We expect this review can provide a new notion of future cancer immunotherapy.


Assuntos
Neoplasias , Macrófagos Associados a Tumor , Autofagia , Humanos , Imunoterapia , Neoplasias/metabolismo , Microambiente Tumoral
8.
Int J Mol Sci ; 22(18)2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34576028

RESUMO

Lung cancer is one of the most common cancers and the leading cause of death in humans worldwide. Non-small-cell lung cancer (NSCLC) accounts for approximately 85% of lung cancer cases and is often diagnosed at a late stage. Among patients with NSCLC, 50% die within 1 year after diagnosis. Even with clinical intervention, the 5-year survival rate is only approximately 20%. Therefore, the development of an advanced therapeutic strategy or novel agent is urgently required for treating NSCLC. Berberine exerts therapeutic activity toward NSCLC; therefore, its activity as an antitumor agent needs to be explored further. In this study, three terpenylated-bromide derivatives of berberrubine were synthesized and their anti-NSCLC activities were evaluated. Each derivative had higher anti-NSCLCs activity than berberrubine and berberine. Among them, 9-O-gernylberberrubine bromide (B4) and 9-O-farnesylberberrubine bromide (B5) showed greater growth inhibition, cell-cycle regulation, in vitro tumorigenesis suppression, and tumor migration reduction. In addition, some degree of apoptosis and autophagic flux blocking was noted in the cells under B4 and B5 treatments. Our study demonstrates that the berberrubine derivatives, B4 and B5, exhibit impressive anti-NSCLC activities and have potential for use as chemotherapeutic agents against NSCLC.


Assuntos
Berberina/análogos & derivados , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células A549 , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Berberina/síntese química , Berberina/química , Berberina/farmacologia , Brometos/química , Carcinogênese/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/patologia , Humanos , Terpenos/síntese química , Terpenos/farmacologia
9.
BMC Bioinformatics ; 21(Suppl 6): 276, 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33203348

RESUMO

BACKGROUND: Biological data has grown explosively with the advance of next-generation sequencing. However, annotating protein function with wet lab experiments is time-consuming. Fortunately, computational function prediction can help wet labs formulate biological hypotheses and prioritize experiments. Gene Ontology (GO) is a framework for unifying the representation of protein function in a hierarchical tree composed of GO terms. RESULTS: We propose GODoc, a general protein GO prediction framework based on sequence information which combines feature engineering, feature reduction, and a novel ​k​-nearest-neighbor algorithm to resolve the multiple GO prediction problem. Comprehensive evaluation on CAFA2 shows that GODoc performs better than two baseline models. In the CAFA3 competition (68 teams), GODoc ranks 10th in Cellular Component Ontology. Regarding the species-specific task, the proposed method ranks 10th and 8th in the eukaryotic Cellular Component Ontology and the prokaryotic Molecular Function Ontology, respectively. In the term-centric task, GODoc performs third and is tied for first for the biofilm formation of Pseudomonas aeruginosa and the long-term memory of Drosophila melanogaster, respectively. CONCLUSIONS: We have developed a novel and effective strategy to incorporate a training procedure into the k-nearest neighbor algorithm (instance-based learning) which is capable of solving the Gene Ontology multiple-label prediction problem, which is especially notable given the thousands of Gene Ontology terms.


Assuntos
Algoritmos , Drosophila melanogaster , Ontologia Genética , Proteínas , Animais , Biologia Computacional , Drosophila melanogaster/genética , Política , Proteínas/genética
10.
Int J Mol Sci ; 21(12)2020 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-32545770

RESUMO

Lung cancer is the leading cause of death in the world, and the most common type of lung cancer is non-small-cell lung cancer (NSCLC), accounting for 85% of lung cancer. Patients with NSCLC, when detected, are mostly in a metastatic stage, and over half of patients diagnosed with NSCLC die within one year after diagnosis; the 5-year survival rate is 24%. However, in patients with metastatic NSCLC, the 5-year survival rate is 6%. Therefore, development of a new therapeutic agent or strategy is urgent for NSCLCs. Berberine has been illustrated to be a therapeutic agent of NSCLC. In the present study, we synthesized six derivatives of berberine, and the anti-NSCLC activity of these agents was examined. Some of them exert increasing proliferation inhibition comparing with berberine. Further studies demonstrated that two of the most effective agents, 9-O-decylberberrubine bromide (B6) and 9-O-dodecylberberrubine bromide (B7), performed cell cycle regulation, in-vitro tumorigenesis inhibition and autophagic flux blocking, but not induction of cellular apoptosis in NSCLC cells. Moreover, B6 and B7 were determined to be green fluorescent and could be penetrated and localized in cellular mitochondria. Herein, B6 and B7, the berberine derivatives we synthesized, revealed better anti-NSCLC activity with berberine and may be used as therapeutic candidates for the treatment of NSCLCs.


Assuntos
Antineoplásicos/síntese química , Berberina/análogos & derivados , Brometos/síntese química , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Neoplasias Pulmonares/metabolismo , Células A549 , Antineoplásicos/química , Antineoplásicos/farmacologia , Brometos/química , Brometos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Estrutura Molecular
11.
BMC Genomics ; 20(Suppl 9): 906, 2019 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-31874640

RESUMO

BACKGROUND: Tandem mass spectrometry allows biologists to identify and quantify protein samples in the form of digested peptide sequences. When performing peptide identification, spectral library search is more sensitive than traditional database search but is limited to peptides that have been previously identified. An accurate tandem mass spectrum prediction tool is thus crucial in expanding the peptide space and increasing the coverage of spectral library search. RESULTS: We propose MS2CNN, a non-linear regression model based on deep convolutional neural networks, a deep learning algorithm. The features for our model are amino acid composition, predicted secondary structure, and physical-chemical features such as isoelectric point, aromaticity, helicity, hydrophobicity, and basicity. MS2CNN was trained with five-fold cross validation on a three-way data split on the large-scale human HCD MS2 dataset of Orbitrap LC-MS/MS downloaded from the National Institute of Standards and Technology. It was then evaluated on a publicly available independent test dataset of human HeLa cell lysate from LC-MS experiments. On average, our model shows better cosine similarity and Pearson correlation coefficient (0.690 and 0.632) than MS2PIP (0.647 and 0.601) and is comparable with pDeep (0.692 and 0.642). Notably, for the more complex MS2 spectra of 3+ peptides, MS2PIP is significantly better than both MS2PIP and pDeep. CONCLUSIONS: We showed that MS2CNN outperforms MS2PIP for 2+ and 3+ peptides and pDeep for 3+ peptides. This implies that MS2CNN, the proposed convolutional neural network model, generates highly accurate MS2 spectra for LC-MS/MS experiments using Orbitrap machines, which can be of great help in protein and peptide identifications. The results suggest that incorporating more data for deep learning model may improve performance.


Assuntos
Redes Neurais de Computação , Espectrometria de Massas em Tandem/métodos , Aprendizado Profundo , Células HeLa , Humanos , Peptídeos/química , Proteínas/química , Análise de Sequência de Proteína
12.
Pharmacol Res ; 139: 41-49, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30391354

RESUMO

Irinotecan (CPT-11), a first-line chemotherapy for advanced colorectal cancer, causes serious diarrhea in patients receiving treatment. The underlying mechanism has been shown that the active metabolite of CPT-11, SN-38, is metabolized to the inactive metabolite SN-38 glucuronide (SN-38 G) during hepatic glucuronidation, and subsequently is exported into the intestine, where SN-38 G is hydrolyzed by bacterial ß-glucuronidase (ßG) to be SN-38, thus leading to intestinal toxicity. Thus, inhibition of the intestinal bacterial ßG activity is expected to prevent CPT-11-induced diarrhea. However, the effects of such inhibition on serum pharmacokinetics of SN-38, the key determinant of CPT-11 treatment, are uncertain. Here, we determined the effects of a potent E. coli ßG (eßG)-specific inhibitor pyrazolo[4,3-c]quinoline derivative (TCH-3562) for the potential use in preventing CPT-11-induced diarrhea. TCH-3562 exhibited efficacious inhibitory potency of endogenous ßG activity in two anaerobes, Eubacteriumsp. and Peptostreptococcus anaerobius. Oral administration of TCH-3562 also effectively reduced the bacterial ßG activity in mice intestine. Moreover, pharmacokinetic analysis of TCH-3562 revealed a relatively low amount of TCH-3562 was detected in the plasma whereas the majority of TCH-3562 was found in the feces. Importantly, co-treatment of CPT-11 and TCH-3562 did not decrease active SN-38 level in mice plasma. Finally, we established that TCH-3562 as an adjuvant treatment showed protective effects on CPT-11-induced diarrhea and had no negative effects on the therapeutic efficacy of CPT-11 in tumor-bearing mice. Therefore, inhibition of the intestinal bacterial ßG activity by the specific inhibitor, TCH-3562, is promising to prevent CPT-11-induced diarrhea while maintaining its anti-tumor efficacy that may have clinical potentials for the treatment with CPT-11.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Proteínas de Bactérias/antagonistas & inibidores , Neoplasias do Colo/tratamento farmacológico , Diarreia/prevenção & controle , Glucuronidase/antagonistas & inibidores , Irinotecano/uso terapêutico , Quinolinas/farmacologia , Animais , Linhagem Celular Tumoral , Diarreia/induzido quimicamente , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Eubacterium/enzimologia , Células HEK293 , Humanos , Masculino , Camundongos Endogâmicos BALB C , Peptostreptococcus/enzimologia
13.
BMC Endocr Disord ; 19(1): 16, 2019 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-30691427

RESUMO

BACKGROUND: Renal hyperparathyroidism is a common complication of chronic kidney disease (CKD) or end-stage renal disease (ESRD) characterized by elevated parathyroid hormone levels secondary to derangements in the homeostasis of calcium, phosphate, and vitamin D. Rapid correction of severe and prolonged hyperparathyroidism by surgical parathyroidectomy in long-term hemodialysis patients occasionally causes hungry bone syndrome. These patients then exhibit severe and long-lasting secondary or tertiary hyperparathyroidism with high bone turnover. CASE PRESENTATION: We report a case of recurrent tertiary hyperparathyroidism after total parathyroidectomy due to supernumerary parathyroid gland in a patient with long-term hemodialysis. Supplementation with intravenous calcium, oral calcium, and vitamin D immediately after patient surgery helps to prevent and treat hungry bone syndrome. CONCLUSIONS: We should prompt a search for the supernumerary parathyroid glands in ESRD patients, who have recurrent or persistent hyperparathyroidism after total parathyroidectomy. ESRD patients are more likely to develop hungry bone syndrome after parathyroidectomy. Prevention and treatment of hungry bone syndrome may be required after ectopic parathyroidectomy in clinical practice.


Assuntos
Hiperparatireoidismo/etiologia , Glândulas Paratireoides/patologia , Paratireoidectomia/efeitos adversos , Diálise Renal/efeitos adversos , Idoso , Humanos , Hiperparatireoidismo/cirurgia , Falência Renal Crônica/terapia , Masculino , Glândulas Paratireoides/cirurgia , Prognóstico , Recidiva
14.
Int J Mol Sci ; 20(22)2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31766223

RESUMO

ß-catenin is a major component of the Wnt/ß-catenin signaling pathway, and is known to play a role in lung tumorigenesis. ß-catenin-interacting protein 1 (CTNNBIP1) is a known repressor of ß-catenin transactivation. However, little is known about the role of CTNNBIP1 in lung cancer. The aim of this study was to carry out a molecular analysis of CTNNBIP1 and its effect on ß-catenin signaling, using samples from lung cancer patients and various lung cancer cell lines. Our results indicate a significant inverse correlation between the CTNNBIP1 mRNA expression levels and the CTNNBIP1 promoter hypermethylation, which suggests that the promoter hypermethylation is responsible for the low levels of CTNNBIP1 present in many lung cancer patient samples. The ectopic expression of CTNNBIP1 is able to reduce the ß-catenin transactivation; this then brings about a decrease in the expression of ß-catenin-targeted genes, such as matrix metalloproteinase 7 (MMP7). Conversely, CTNNBIP1 knockdown is able to increase ß-catenin transactivation and the expression of MMP7. In agreement with these findings, a low level of CTNNBIP1 was found to be correlated with a high level of MMP7 when a publicly available microarray dataset for lung cancer was analyzed. Also, in agreement with the above, the ectopic expression of CTNNBIP1 inhibits the migration of lung cancer cells, whereas the CTNNBIP1 knockdown increases cancer cell migration. Our findings suggest that CTNNBIP1 is a suppressor of cancer migration, thus making it a potential prognostic predictor for lung cancer.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , beta Catenina/genética , Linhagem Celular Tumoral , Movimento Celular , Feminino , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Via de Sinalização Wnt , beta Catenina/metabolismo
15.
Brief Bioinform ; 17(6): 1009-1023, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-26615024

RESUMO

This review provides an overview on the development of Multiple sequence alignment (MSA) methods and their main applications. It is focused on progress made over the past decade. The three first sections review recent algorithmic developments for protein, RNA/DNA and genomic alignments. The fourth section deals with benchmarks and explores the relationship between empirical and simulated data, along with the impact on method developments. The last part of the review gives an overview on available MSA local reliability estimators and their dependence on various algorithmic properties of available methods.


Assuntos
Alinhamento de Sequência , Algoritmos , DNA , Genômica , Proteínas , Reprodutibilidade dos Testes
16.
Nucleic Acids Res ; 44(W1): W339-43, 2016 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-27106060

RESUMO

The PSI/TM-Coffee web server performs multiple sequence alignment (MSA) of proteins by combining homology extension with a consistency based alignment approach. Homology extension is performed with Position Specific Iterative (PSI) BLAST searches against a choice of redundant and non-redundant databases. The main novelty of this server is to allow databases of reduced complexity to rapidly perform homology extension. This server also gives the possibility to use transmembrane proteins (TMPs) reference databases to allow even faster homology extension on this important category of proteins. Aside from an MSA, the server also outputs topological prediction of TMPs using the HMMTOP algorithm. Previous benchmarking of the method has shown this approach outperforms the most accurate alignment methods such as MSAProbs, Kalign, PROMALS, MAFFT, ProbCons and PRALINE™. The web server is available at http://tcoffee.crg.cat/tmcoffee.


Assuntos
Algoritmos , Proteínas de Membrana/química , Análise de Sequência de Proteína/estatística & dados numéricos , Interface Usuário-Computador , Sequência de Aminoácidos , Gráficos por Computador , Bases de Dados de Proteínas , Armazenamento e Recuperação da Informação , Internet , Proteínas de Membrana/genética , Domínios Proteicos , Estrutura Secundária de Proteína , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos
17.
J Cell Biochem ; 118(6): 1387-1400, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-27862220

RESUMO

For several decades, cholesterol has been thought to cause ASCVD. Limiting dietary cholesterol intake has been recommended to reduce the risk of the disease. However, several recent epidemiological studies do not support a relationship between dietary cholesterol and/or blood cholesterol and ASCVD. Consequently, the role of cholesterol in atherogenesis is now uncertain. Much evidence indicates that TGF-ß, an anti-inflammatory cytokine, protects against ASCVD and that suppression of canonical TGF-ß signaling (Smad2-dependent) is involved in atherogenesis. We had hypothesized that cholesterol causes ASCVD by suppressing canonical TGF-ß signaling in vascular endothelium. To test this hypothesis, we determine the effects of cholesterol, 7-dehydrocholesterol (7-DHC; the biosynthetic precursor of cholesterol), and other sterols on canonical TGF-ß signaling. We use Mv1Lu cells (a model cell system for studying TGF-ß activity) stably expressing the Smad2-dependent luciferase reporter gene. We demonstrate that 7-DHC (but not cholesterol or other sterols) effectively suppresses the TGF-ß-stimulated luciferase activity. We also demonstrate that 7-DHC suppresses TGF-ß-stimulated luciferase activity by promoting lipid raft/caveolae formation and subsequently recruiting cell-surface TGF-ß receptors from non-lipid raft microdomains to lipid rafts/caveolae where TGF-ß receptors become inactive in transducing canonical signaling and undergo rapid degradation upon TGF-ß binding. We determine this by cell-surface 125 I-TGF-ß-cross-linking and sucrose density gradient ultracentrifugation. We further demonstrate that methyl-ß-cyclodextrin (MßCD), a sterol-chelating agent, reverses 7-DHC-induced suppression of TGF-ß-stimulated luciferase activity by extrusion of 7-DHC from resident lipid rafts/caveolae. These results suggest that 7-DHC, but not cholesterol, promotes lipid raft/caveolae formation, leading to suppression of canonical TGF-ß signaling and atherogenesis. J. Cell. Biochem. 118: 1387-1400, 2017. © 2016 Wiley Periodicals, Inc.


Assuntos
Aterosclerose/metabolismo , Colesterol/farmacologia , Desidrocolesteróis/farmacologia , Fator de Crescimento Transformador beta/metabolismo , Cavéolas/metabolismo , Linhagem Celular , Humanos , Microdomínios da Membrana/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína Smad2/metabolismo
18.
Genome Res ; 24(12): 2077-89, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25273068

RESUMO

Multiple sequence alignments (MSAs) are a prerequisite for a wide variety of evolutionary analyses. Published assessments and benchmark data sets for protein and, to a lesser extent, global nucleotide MSAs are available, but less effort has been made to establish benchmarks in the more general problem of whole-genome alignment (WGA). Using the same model as the successful Assemblathon competitions, we organized a competitive evaluation in which teams submitted their alignments and then assessments were performed collectively after all the submissions were received. Three data sets were used: Two were simulated and based on primate and mammalian phylogenies, and one was comprised of 20 real fly genomes. In total, 35 submissions were assessed, submitted by 10 teams using 12 different alignment pipelines. We found agreement between independent simulation-based and statistical assessments, indicating that there are substantial accuracy differences between contemporary alignment tools. We saw considerable differences in the alignment quality of differently annotated regions and found that few tools aligned the duplications analyzed. We found that many tools worked well at shorter evolutionary distances, but fewer performed competitively at longer distances. We provide all data sets, submissions, and assessment programs for further study and provide, as a resource for future benchmarking, a convenient repository of code and data for reproducing the simulation assessments.


Assuntos
Genoma , Genômica/métodos , Alinhamento de Sequência/métodos , Software , Animais , Biologia Computacional/métodos , Simulação por Computador , Conjuntos de Dados como Assunto , Estudo de Associação Genômica Ampla , Humanos , Mamíferos/genética , Filogenia , Reprodutibilidade dos Testes
19.
Nucleic Acids Res ; 43(W1): W3-6, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25855806

RESUMO

This article introduces the Transitive Consistency Score (TCS) web server; a service making it possible to estimate the local reliability of protein multiple sequence alignments (MSAs) using the TCS index. The evaluation can be used to identify the aligned positions most likely to contain structurally analogous residues and also most likely to support an accurate phylogenetic reconstruction. The TCS scoring scheme has been shown to be accurate predictor of structural alignment correctness among commonly used methods. It has also been shown to outperform common filtering schemes like Gblocks or trimAl when doing MSA post-processing prior to phylogenetic tree reconstruction. The web server is available from http://tcoffee.crg.cat/tcs.


Assuntos
Filogenia , Alinhamento de Sequência/métodos , Análise de Sequência de Proteína , Software , Algoritmos , Internet
20.
Molecules ; 22(6)2017 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-28587210

RESUMO

Metastasis is common in lung cancer and is associated with poor clinical outcomes and increased mortality. Curcumin is a natural anti-cancer agent that inhibits the metastasis of various cancers by modulating the expression of micro (mi) RNAs such as miR-98, which acts as a tumor suppressor. This study investigated the effect of curcumin on miR-98 expression and in vitro cell line growth and invasiveness in lung cancer. Curcumin treatment enhanced the expression of miR-98 and reduced that of the miR-98 target gene LIN28A as well as matrix metalloproteinase (MMP) 2 and MMP9 in vitro and in vivo. MiR-98 overexpression suppressed lung cancer cell migration and invasion by inhibiting LIN28A-induced MMP2 and MMP9 expression. Meanwhile, LIN28A level was downregulated by overexpression of miR-98 mimic. Induction of miR-98 by curcumin treatment suppressed MMP2 and MMP9 by targeting LIN28A. These findings provide insight into the mechanisms by which curcumin suppresses lung cancer cell line growth in vitro and in vivo and invasiveness in vitro.


Assuntos
Antineoplásicos/farmacologia , Curcumina/farmacologia , Neoplasias Pulmonares/genética , MicroRNAs/genética , Proteínas de Ligação a RNA/genética , Ativação Transcricional/efeitos dos fármacos , Regiões 3' não Traduzidas , Animais , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Interferência de RNA , Ensaios Antitumorais Modelo de Xenoenxerto
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