Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 59
Filtrar
1.
Nat Biotechnol ; 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38744947

RESUMO

Cancer immunotherapy with autologous chimeric antigen receptor (CAR) T cells faces challenges in manufacturing and patient selection that could be avoided by using 'off-the-shelf' products, such as allogeneic CAR natural killer T (AlloCAR-NKT) cells. Previously, we reported a system for differentiating human hematopoietic stem and progenitor cells into AlloCAR-NKT cells, but the use of three-dimensional culture and xenogeneic feeders precluded its clinical application. Here we describe a clinically guided method to differentiate and expand IL-15-enhanced AlloCAR-NKT cells with high yield and purity. We generated AlloCAR-NKT cells targeting seven cancers and, in a multiple myeloma model, demonstrated their antitumor efficacy, expansion and persistence. The cells also selectively depleted immunosuppressive cells in the tumor microenviroment and antagonized tumor immune evasion via triple targeting of CAR, TCR and NK receptors. They exhibited a stable hypoimmunogenic phenotype associated with epigenetic and signaling regulation and did not induce detectable graft versus host disease or cytokine release syndrome. These properties of AlloCAR-NKT cells support their potential for clinical translation.

4.
Nat Struct Mol Biol ; 30(8): 1193-1206, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37580627

RESUMO

The nuclear folding of chromosomes relative to nuclear bodies is an integral part of gene function. Here, we demonstrate that population-based modeling-from ensemble Hi-C data-provides a detailed description of the nuclear microenvironment of genes and its role in gene function. We define the microenvironment by the subnuclear positions of genomic regions with respect to nuclear bodies, local chromatin compaction, and preferences in chromatin compartmentalization. These structural descriptors are determined in single-cell models, thereby revealing the structural variability between cells. We demonstrate that the microenvironment of a genomic region is linked to its functional potential in gene transcription, replication, and chromatin compartmentalization. Some chromatin regions feature a strong preference for a single microenvironment, due to association with specific nuclear bodies in most cells. Other chromatin shows high structural variability, which is a strong indicator of functional heterogeneity. Moreover, we identify specialized nuclear microenvironments, which distinguish chromatin in different functional states and reveal a key role of nuclear speckles in chromosome organization. We demonstrate that our method produces highly predictive three-dimensional genome structures, which accurately reproduce data from a variety of orthogonal experiments, thus considerably expanding the range of Hi-C data analysis.


Assuntos
Núcleo Celular , Cromatina , Núcleo Celular/genética , Núcleo Celular/química , Cromatina/genética , Cromossomos/genética , Genoma
5.
Proc Natl Acad Sci U S A ; 120(28): e2305236120, 2023 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-37399400

RESUMO

Plasma cell-free DNA (cfDNA) is a noninvasive biomarker for cell death of all organs. Deciphering the tissue origin of cfDNA can reveal abnormal cell death because of diseases, which has great clinical potential in disease detection and monitoring. Despite the great promise, the sensitive and accurate quantification of tissue-derived cfDNA remains challenging to existing methods due to the limited characterization of tissue methylation and the reliance on unsupervised methods. To fully exploit the clinical potential of tissue-derived cfDNA, here we present one of the largest comprehensive and high-resolution methylation atlas based on 521 noncancer tissue samples spanning 29 major types of human tissues. We systematically identified fragment-level tissue-specific methylation patterns and extensively validated them in orthogonal datasets. Based on the rich tissue methylation atlas, we develop the first supervised tissue deconvolution approach, a deep-learning-powered model, cfSort, for sensitive and accurate tissue deconvolution in cfDNA. On the benchmarking data, cfSort showed superior sensitivity and accuracy compared to the existing methods. We further demonstrated the clinical utilities of cfSort with two potential applications: aiding disease diagnosis and monitoring treatment side effects. The tissue-derived cfDNA fraction estimated from cfSort reflected the clinical outcomes of the patients. In summary, the tissue methylation atlas and cfSort enhanced the performance of tissue deconvolution in cfDNA, thus facilitating cfDNA-based disease detection and longitudinal treatment monitoring.


Assuntos
Ácidos Nucleicos Livres , Aprendizado Profundo , Humanos , Ácidos Nucleicos Livres/genética , Metilação de DNA , Biomarcadores , Regiões Promotoras Genéticas , Biomarcadores Tumorais/genética
6.
Nat Protoc ; 18(5): 1563-1583, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36849599

RESUMO

Cell-free DNA (cfDNA) in blood, viewed as a surrogate for tumor biopsy, has many clinical applications, including diagnosing cancer, guiding cancer treatment and monitoring treatment response. All these applications depend on an indispensable, yet underdeveloped task: detecting somatic mutations from cfDNA. The task is challenging because of the low tumor fraction in cfDNA. Recently, we developed the computational method cfSNV, the first method that comprehensively considers the properties of cfDNA for the sensitive detection of mutations from cfDNA. cfSNV vastly outperformed the conventional methods that were developed primarily for calling mutations from solid tumor tissues. cfSNV can accurately detect mutations in cfDNA even with medium-coverage (e.g., ≥200×) sequencing, which makes whole-exome sequencing (WES) of cfDNA a viable option for various clinical utilities. Here, we present a user-friendly cfSNV package that exhibits fast computation and convenient user options. We also built a Docker image of it, which is designed to enable researchers and clinicians with a limited computational background to easily carry out analyses on both high-performance computing platforms and local computers. Mutation calling from a standard preprocessed WES dataset (~250× and ~70 million base pair target size) can be carried out in 3 h on a server with eight virtual CPUs and 32 GB of random access memory.


Assuntos
Ácidos Nucleicos Livres , Neoplasias , Humanos , Ácidos Nucleicos Livres/genética , Neoplasias/diagnóstico , Neoplasias/genética , Mutação , Software , Sequenciamento de Nucleotídeos em Larga Escala/métodos
7.
Hepatology ; 77(3): 774-788, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35908246

RESUMO

BACKGROUND AND AIMS: The sensitivity of current surveillance methods for detecting early-stage hepatocellular carcinoma (HCC) is suboptimal. Extracellular vesicles (EVs) are promising circulating biomarkers for early cancer detection. In this study, we aim to develop an HCC EV-based surface protein assay for early detection of HCC. APPROACH AND RESULTS: Tissue microarray was used to evaluate four potential HCC-associated protein markers. An HCC EV surface protein assay, composed of covalent chemistry-mediated HCC EV purification and real-time immuno-polymerase chain reaction readouts, was developed and optimized for quantifying subpopulations of EVs. An HCC EV ECG score, calculated from the readouts of three HCC EV subpopulations ( E pCAM + CD63 + , C D147 + CD63 + , and G PC3 + CD63 + HCC EVs), was established for detecting early-stage HCC. A phase 2 biomarker study was conducted to evaluate the performance of ECG score in a training cohort ( n  = 106) and an independent validation cohort ( n  = 72).Overall, 99.7% of tissue microarray stained positive for at least one of the four HCC-associated protein markers (EpCAM, CD147, GPC3, and ASGPR1) that were subsequently validated in HCC EVs. In the training cohort, HCC EV ECG score demonstrated an area under the receiver operating curve (AUROC) of 0.95 (95% confidence interval [CI], 0.90-0.99) for distinguishing early-stage HCC from cirrhosis with a sensitivity of 91% and a specificity of 90%. The AUROCs of the HCC EV ECG score remained excellent in the validation cohort (0.93; 95% CI, 0.87-0.99) and in the subgroups by etiology (viral: 0.95; 95% CI, 0.90-1.00; nonviral: 0.94; 95% CI, 0.88-0.99). CONCLUSION: HCC EV ECG score demonstrated great potential for detecting early-stage HCC. It could augment current surveillance methods and improve patients' outcomes.


Assuntos
Carcinoma Hepatocelular , Vesículas Extracelulares , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/patologia , Biomarcadores Tumorais/análise , Vesículas Extracelulares/química , Proteínas de Membrana , Eletrocardiografia , Glipicanas
8.
Nat Commun ; 13(1): 5566, 2022 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-36175411

RESUMO

Early cancer detection by cell-free DNA faces multiple challenges: low fraction of tumor cell-free DNA, molecular heterogeneity of cancer, and sample sizes that are not sufficient to reflect diverse patient populations. Here, we develop a cancer detection approach to address these challenges. It consists of an assay, cfMethyl-Seq, for cost-effective sequencing of the cell-free DNA methylome (with > 12-fold enrichment over whole genome bisulfite sequencing in CpG islands), and a computational method to extract methylation information and diagnose patients. Applying our approach to 408 colon, liver, lung, and stomach cancer patients and controls, at 97.9% specificity we achieve 80.7% and 74.5% sensitivity in detecting all-stage and early-stage cancer, and 89.1% and 85.0% accuracy for locating tissue-of-origin of all-stage and early-stage cancer, respectively. Our approach cost-effectively retains methylome profiles of cancer abnormalities, allowing us to learn new features and expand to other cancer types as training cohorts grow.


Assuntos
Ácidos Nucleicos Livres , Neoplasias Gástricas , Ácidos Nucleicos Livres/genética , Análise Custo-Benefício , Detecção Precoce de Câncer , Epigenoma , Humanos , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/genética
9.
Nat Methods ; 19(8): 938-949, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35817938

RESUMO

A multitude of sequencing-based and microscopy technologies provide the means to unravel the relationship between the three-dimensional organization of genomes and key regulatory processes of genome function. Here, we develop a multimodal data integration approach to produce populations of single-cell genome structures that are highly predictive for nuclear locations of genes and nuclear bodies, local chromatin compaction and spatial segregation of functionally related chromatin. We demonstrate that multimodal data integration can compensate for systematic errors in some of the data and can greatly increase accuracy and coverage of genome structure models. We also show that alternative combinations of different orthogonal data sources can converge to models with similar predictive power. Moreover, our study reveals the key contributions of low-frequency ('rare') interchromosomal contacts to accurately predicting the global nuclear architecture, including the positioning of genes and chromosomes. Overall, our results highlight the benefits of multimodal data integration for genome structure analysis, available through the Integrative Genome Modeling software package.


Assuntos
Cromatina , Cromossomos , Núcleo Celular , Cromatina/genética , Cromossomos/genética , Genoma
10.
J Comput Biol ; 29(8): 769-781, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35671506

RESUMO

Developing cancer prognostic models using multiomics data is a major goal of precision oncology. DNA methylation provides promising prognostic biomarkers, which have been used to predict survival and treatment response in solid tumor or plasma samples. This review article presents an overview of recently published computational analyses on DNA methylation for cancer prognosis. To address the challenges of survival analysis with high-dimensional methylation data, various feature selection methods have been applied to screen a subset of informative markers. Using candidate markers associated with survival, prognostic models either predict risk scores or stratify patients into subtypes. The model's discriminatory power can be assessed by multiple evaluation metrics. Finally, we discuss the limitations of existing studies and present the prospects of applying machine learning algorithms to fully exploit the prognostic value of DNA methylation.


Assuntos
Metilação de DNA , Neoplasias , Biomarcadores Tumorais/genética , Humanos , Neoplasias/diagnóstico , Neoplasias/genética , Medicina de Precisão , Análise de Sobrevida
11.
Clin Cancer Res ; 28(9): 1841-1853, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35149536

RESUMO

PURPOSE: Cell-free DNA (cfDNA) offers a noninvasive approach to monitor cancer. Here we develop a method using whole-exome sequencing (WES) of cfDNA for simultaneously monitoring the full spectrum of cancer treatment outcomes, including minimal residual disease (MRD), recurrence, evolution, and second primary cancers. EXPERIMENTAL DESIGN: Three simulation datasets were generated from 26 patients with cancer to benchmark the detection performance of MRD/recurrence and second primary cancers. For further validation, cfDNA samples (n = 76) from patients with cancer (n = 35) with six different cancer types were used for performance validation during various treatments. RESULTS: We present a cfDNA-based cancer monitoring method, named cfTrack. Taking advantage of the broad genome coverage of WES data, cfTrack can sensitively detect MRD and cancer recurrence by integrating signals across known clonal tumor mutations of a patient. In addition, cfTrack detects tumor evolution and second primary cancers by de novo identifying emerging tumor mutations. A series of machine learning and statistical denoising techniques are applied to enhance the detection power. On the simulation data, cfTrack achieved an average AUC of 99% on the validation dataset and 100% on the independent dataset in detecting recurrence in samples with tumor fractions ≥0.05%. In addition, cfTrack yielded an average AUC of 88% in detecting second primary cancers in samples with tumor fractions ≥0.2%. On real data, cfTrack accurately monitors tumor evolution during treatment, which cannot be accomplished by previous methods. CONCLUSIONS: Our results demonstrated that cfTrack can sensitively and specifically monitor the full spectrum of cancer treatment outcomes using exome-wide mutation analysis of cfDNA.


Assuntos
Ácidos Nucleicos Livres , Segunda Neoplasia Primária , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/genética , Ácidos Nucleicos Livres/genética , Exoma/genética , Humanos , Mutação , Recidiva Local de Neoplasia/genética , Neoplasia Residual/genética , Segunda Neoplasia Primária/genética , Resultado do Tratamento , Sequenciamento do Exoma
12.
NAR Genom Bioinform ; 3(3): lqab066, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34377977

RESUMO

Antibiotic resistance in bacteria limits the effect of corresponding antibiotics, and the classification of antibiotic resistance genes (ARGs) is important for the treatment of bacterial infections and for understanding the dynamics of microbial communities. Although several methods have been developed to classify ARGs, none of them work well when the ARGs diverge from those in the reference ARG databases. We develop a novel method, ARG-SHINE, for ARG classification. ARG-SHINE utilizes state-of-the-art learning to rank machine learning approach to ensemble three component methods with different features, including sequence homology, protein domain/family/motif and raw amino acid sequences for the deep convolutional neural network. Compared with other methods, ARG-SHINE achieves better performance on two benchmark datasets in terms of accuracy, macro-average f1-score and weighted-average f1-score. ARG-SHINE is used to classify newly discovered ARGs through functional screening and achieves high prediction accuracy. ARG-SHINE is freely available at https://github.com/ziyewang/ARG_SHINE.

13.
Nat Commun ; 12(1): 4172, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34234141

RESUMO

Cell-free DNA (cfDNA) is attractive for many applications, including detecting cancer, identifying the tissue of origin, and monitoring. A fundamental task underlying these applications is SNV calling from cfDNA, which is hindered by the very low tumor content. Thus sensitive and accurate detection of low-frequency mutations (<5%) remains challenging for existing SNV callers. Here we present cfSNV, a method incorporating multi-layer error suppression and hierarchical mutation calling, to address this challenge. Furthermore, by leveraging cfDNA's comprehensive coverage of tumor clonal landscape, cfSNV can profile mutations in subclones. In both simulated and real patient data, cfSNV outperforms existing tools in sensitivity while maintaining high precision. cfSNV enhances the clinical utilities of cfDNA by improving mutation detection performance in medium-depth sequencing data, therefore making Whole-Exome Sequencing a viable option. As an example, we demonstrate that the tumor mutation profile from cfDNA WES data can provide an effective biomarker to predict immunotherapy outcomes.


Assuntos
DNA Tumoral Circulante/genética , Análise Mutacional de DNA/métodos , Sequenciamento do Exoma/métodos , Inibidores de Checkpoint Imunológico/farmacologia , Neoplasias/genética , Adulto , Anticorpos Monoclonais Humanizados/farmacologia , Anticorpos Monoclonais Humanizados/uso terapêutico , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/genética , Biópsia , DNA Tumoral Circulante/sangue , Simulação por Computador , Conjuntos de Dados como Assunto , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Humanos , Inibidores de Checkpoint Imunológico/uso terapêutico , Masculino , Pessoa de Meia-Idade , Mutação , Neoplasias/sangue , Neoplasias/tratamento farmacológico , Neoplasias/mortalidade , Polimorfismo de Nucleotídeo Único , Prognóstico , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Intervalo Livre de Progressão , Sensibilidade e Especificidade
15.
J Transl Med ; 18(1): 5, 2020 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-31906978

RESUMO

BACKGROUND: Sepsis remains a major challenge in intensive care units, causing unacceptably high mortality rates due to the lack of rapid diagnostic tools with sufficient sensitivity. Therefore, there is an urgent need to replace time-consuming blood cultures with a new method. Ideally, such a method also provides comprehensive profiling of pathogenic bacteria to facilitate the treatment decision. METHODS: We developed a Random Forest with balanced subsampling to screen for pathogenic bacteria and diagnose sepsis based on cell-free DNA (cfDNA) sequencing data in a small blood sample. In addition, we constructed a bacterial co-occurrence network, based on a set of normal and sepsis samples, to infer unobserved bacteria. RESULTS: Based solely on cfDNA sequencing information from three independent datasets of sepsis, we distinguish sepsis from healthy samples with a satisfactory performance. This strategy also provides comprehensive bacteria profiling, permitting doctors to choose the best treatment strategy for a sepsis case. CONCLUSIONS: The combination of sepsis identification and bacteria-inferring strategies is a success for noninvasive cfDNA-based diagnosis, which has the potential to greatly enhance efficiency in disease detection and provide a comprehensive understanding of pathogens. For comparison, where a culture-based analysis of pathogens takes up to 5 days and is effective for only a third to a half of patients, cfDNA sequencing can be completed in just 1 day and our method can identify the majority of pathogens in all patients.


Assuntos
Ácidos Nucleicos Livres , Sepse , Bactérias/genética , DNA Bacteriano/genética , Humanos , Unidades de Terapia Intensiva , Sepse/diagnóstico
16.
Precis Clin Med ; 2(3): 131-139, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31598384

RESUMO

Circulating cell-free DNAs (cfDNAs) are fragmented DNA molecules released into the blood by cells. Previous studies have suggested that mitochondria-originated cfDNA fragments (mt-cfDNAs) in cancer patients are more fragmented than those from healthy controls. However, it is still unknown where these short mt-cfDNAs originate, and whether the length of mt-cfDNAs can be correlated with tumor burden and cancer progression. In this study, we first performed whole-genome sequencing analysis (WGS) of cfDNAs from a human tumor cell line-xenotransplantation mouse model and found that mt-cfDNAs released from transplanted tumor cells were shorter than the mouse counterpart. We next analyzed blood cfDNA samples from hepatocellular carcinoma and prostate cancer patients and found that mt-cfDNA lengths were inversely related to tumor size as well as the concentration of circulating tumor DNA. Our study suggested that monitoring the size of mt-cfDNAs in cancer patients would be a useful way to estimate tumor burden and cancer progression.

17.
Bioinformatics ; 35(17): 3127-3132, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-30668638

RESUMO

MOTIVATION: In recent years, several experimental studies have revealed that the microRNAs (miRNAs) in serum, plasma, exosome and whole blood are dysregulated in various types of diseases, indicating that the circulating miRNAs may serve as potential noninvasive biomarkers for disease diagnosis and prognosis. However, no database has been constructed to integrate the large-scale circulating miRNA profiles, explore the functional pathways involved and predict the potential biomarkers using feature selection between the disease conditions. Although there have been several studies attempting to generate a circulating miRNA database, they have not yet integrated the large-scale circulating miRNA profiles or provided the biomarker-selection function using machine learning methods. RESULTS: To fill this gap, we constructed the Circulating MicroRNA Expression Profiling (CMEP) database for integrating, analyzing and visualizing the large-scale expression profiles of phenotype-specific circulating miRNAs. The CMEP database contains massive datasets that were manually curated from NCBI GEO and the exRNA Atlas, including 66 datasets, 228 subsets and 10 419 samples. The CMEP provides the differential expression circulating miRNAs analysis and the KEGG functional pathway enrichment analysis. Furthermore, to provide the function of noninvasive biomarker discovery, we implemented several feature-selection methods, including ridge regression, lasso regression, support vector machine and random forests. Finally, we implemented a user-friendly web interface to improve the user experience and to visualize the data and results of CMEP. AVAILABILITY AND IMPLEMENTATION: CMEP is accessible at http://syslab5.nchu.edu.tw/CMEP.


Assuntos
Bases de Dados Factuais , Biomarcadores , MicroRNA Circulante , Exossomos , Perfilação da Expressão Gênica
18.
J Cell Mol Med ; 23(1): 395-404, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30338927

RESUMO

The seasonal outbreaks of influenza infection cause globally respiratory illness, or even death in all age groups. Given early-warning signals preceding the influenza outbreak, timely intervention such as vaccination and isolation management effectively decrease the morbidity. However, it is usually a difficult task to achieve the real-time prediction of influenza outbreak due to its complexity intertwining both biological systems and social systems. By exploring rich dynamical and high-dimensional information, our dynamic network marker/biomarker (DNM/DNB) method opens a new way to identify the tipping point prior to the catastrophic transition into an influenza pandemics. In order to detect the early-warning signals before the influenza outbreak by applying DNM method, the historical information of clinic hospitalization caused by influenza infection between years 2009 and 2016 were extracted and assembled from public records of Tokyo and Hokkaido, Japan. The early-warning signal, with an average of 4-week window lead prior to each seasonal outbreak of influenza, was provided by DNM-based on the hospitalization records, providing an opportunity to apply proactive strategies to prevent or delay the onset of influenza outbreak. Moreover, the study on the dynamical changes of hospitalization in local district networks unveils the influenza transmission dynamics or landscape in network level.


Assuntos
Biomarcadores/metabolismo , Influenza Humana/diagnóstico , Surtos de Doenças , Progressão da Doença , Humanos , Influenza Humana/metabolismo
19.
Nucleic Acids Res ; 46(15): e89, 2018 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-29897492

RESUMO

The detection of tumor-derived cell-free DNA in plasma is one of the most promising directions in cancer diagnosis. The major challenge in such an approach is how to identify the tiny amount of tumor DNAs out of total cell-free DNAs in blood. Here we propose an ultrasensitive cancer detection method, termed 'CancerDetector', using the DNA methylation profiles of cell-free DNAs. The key of our method is to probabilistically model the joint methylation states of multiple adjacent CpG sites on an individual sequencing read, in order to exploit the pervasive nature of DNA methylation for signal amplification. Therefore, CancerDetector can sensitively identify a trace amount of tumor cfDNAs in plasma, at the level of individual reads. We evaluated CancerDetector on the simulated data, and showed a high concordance of the predicted and true tumor fraction. Testing CancerDetector on real plasma data demonstrated its high sensitivity and specificity in detecting tumor cfDNAs. In addition, the predicted tumor fraction showed great consistency with tumor size and survival outcome. Note that all of those testing were performed on sequencing data at low to medium coverage (1× to 10×). Therefore, CancerDetector holds the great potential to detect cancer early and cost-effectively.


Assuntos
Algoritmos , Ácidos Nucleicos Livres/genética , Biologia Computacional/métodos , Metilação de DNA , Neoplasias/diagnóstico , Ácidos Nucleicos Livres/química , Ilhas de CpG/genética , DNA de Neoplasias/química , DNA de Neoplasias/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Neoplasias/sangue , Neoplasias/genética , Curva ROC , Reprodutibilidade dos Testes
20.
Nat Protoc ; 13(5): 915-926, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29622804

RESUMO

Chromosome conformation capture technologies such as Hi-C are widely used to investigate the spatial organization of genomes. Because genome structures can vary considerably between individual cells of a population, interpreting ensemble-averaged Hi-C data can be challenging, in particular for long-range and interchromosomal interactions. We pioneered a probabilistic approach for the generation of a population of distinct diploid 3D genome structures consistent with all the chromatin-chromatin interaction probabilities from Hi-C experiments. Each structure in the population is a physical model of the genome in 3D. Analysis of these models yields new insights into the causes and the functional properties of the genome's organization in space and time. We provide a user-friendly software package, called PGS, which runs on local machines (for practice runs) and high-performance computing platforms. PGS takes a genome-wide Hi-C contact frequency matrix, along with information about genome segmentation, and produces an ensemble of 3D genome structures entirely consistent with the input. The software automatically generates an analysis report, and provides tools to extract and analyze the 3D coordinates of specific domains. Basic Linux command-line knowledge is sufficient for using this software. A typical running time of the pipeline is ∼3 d with 300 cores on a computer cluster to generate a population of 1,000 diploid genome structures at topological-associated domain (TAD)-level resolution.


Assuntos
Cromatina/ultraestrutura , Cromossomos/ultraestrutura , Biologia Computacional/métodos , Técnicas Citológicas/métodos , Imageamento Tridimensional , Conformação Molecular , Software , Diploide , Modelos Biológicos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA