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1.
Microbiol Spectr ; 9(2): e0051721, 2021 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-34643449

RESUMEN

Endosymbiotic Wolbachia bacteria are known to influence the host physiology, microbiota composition, and dissemination of pathogens. We surveyed a population of Tabanus nigrovittatus, commonly referred to as "greenheads," from Crane Beach (Ipswich, MA, USA) for the presence of the alphaproteobacterial symbiont Wolbachia. We studied the COI (mitochondrial cytochrome oxidase) marker gene to evaluate the phylogenetic diversity of the studied specimens. The DNA sequences show strong similarity (between 99.9 and 98%) among the collected specimens but lower similarity to closely related entries in the NCBI database (only between 96.3 and 94.7%), suggesting a more distant relatedness. Low levels of Wolbachia presence necessitated a nested PCR approach, and using 5 markers (ftsZ, fbpA, dnaA, coxA, and gatB), we determined that two recognized "supergroups" of Wolbachia species were represented in the studied specimens, members of clades A and B. Using next-generation sequencing, we also surveyed the insect gut microbiomes of a subset of flies, using Illumina and PacBio 16S rRNA gene sequencing with barcoded primers. The composition of Proteobacteria also varied from fly to fly, with components belonging to Gammaproteobacteria making up the largest percentage of organisms (30 to 70%) among the microbiome samples. Most of the samples showed the presence of Spiroplasma, a member of the phylum Mollicutes, although the frequency of its presence was variable, ranging from 2 to 57%. Another noteworthy bacterial phylum consistently identified was Firmicutes, though the read abundances were typically below 10%. Of interest is an association between Wolbachia presence and higher Alphaproteobacteria representation in the microbiomes, suggesting that the presence of Wolbachia affects the host microbiome. IMPORTANCE Tabanus nigrovittatus greenhead populations contain two supergroups of Wolbachia endosymbionts, members of supergroups A and B. Analysis of the greenhead microbiome using next-generation sequencing revealed that the majority of bacterial species detected belonged to Gammaproteobacteria, with most of the samples also showing the presence of Spiroplasma, a member of the Mollicutes phylum also known to infect insects. An association between Wolbachia presence and higher Alphaproteobacteria representation in the microbiomes suggests that Wolbachia presence affects the host microbiome composition.


Asunto(s)
Bacterias/aislamiento & purificación , Dípteros/microbiología , Microbiota , Wolbachia/aislamiento & purificación , Animales , Bacterias/clasificación , Bacterias/genética , Filogenia , Wolbachia/clasificación , Wolbachia/genética
2.
Microb Genom ; 6(12)2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33295865

RESUMEN

Wolbachia are alpha-proteobacteria symbionts infecting a large range of arthropod species and two different families of nematodes. Interestingly, these endosymbionts are able to induce diverse phenotypes in their hosts: they are reproductive parasites within many arthropods, nutritional mutualists within some insects and obligate mutualists within their filarial nematode hosts. Defining Wolbachia 'species' is controversial and so they are commonly classified into 17 different phylogenetic lineages, termed supergroups, named A-F, H-Q and S. However, available genomic data remain limited and not representative of the full Wolbachia diversity; indeed, of the 24 complete genomes and 55 draft genomes of Wolbachia available to date, 84 % belong to supergroups A and B, exclusively composed of Wolbachia from arthropods. For the current study, we took advantage of a recently developed DNA-enrichment method to produce four complete genomes and two draft genomes of Wolbachia from filarial nematodes. Two complete genomes, wCtub and wDcau, are the smallest Wolbachia genomes sequenced to date (863 988 bp and 863 427 bp, respectively), as well as the first genomes representing supergroup J. These genomes confirm the validity of this supergroup, a controversial clade due to weaknesses of the multilocus sequence typing approach. We also produced the first draft Wolbachia genome from a supergroup F filarial nematode representative (wMhie), two genomes from supergroup D (wLsig and wLbra) and the complete genome of wDimm from supergroup C. Our new data confirm the paradigm of smaller Wolbachia genomes from filarial nematodes containing low levels of transposable elements and the absence of intact bacteriophage sequences, unlike many Wolbachia from arthropods, where both are more abundant. However, we observe differences among the Wolbachia genomes from filarial nematodes: no global co-evolutionary pattern, strong synteny between supergroup C and supergroup J Wolbachia, and more transposable elements observed in supergroup D Wolbachia compared to the other supergroups. Metabolic pathway analysis indicates several highly conserved pathways (haem and nucleotide biosynthesis, for example) as opposed to more variable pathways, such as vitamin B biosynthesis, which might be specific to certain host-symbiont associations. Overall, there appears to be no single Wolbachia-filarial nematode pattern of co-evolution or symbiotic relationship.


Asunto(s)
Filarioidea/microbiología , Análisis de Secuencia de ADN/métodos , Wolbachia/clasificación , Animales , Bases de Datos Genéticas , Evolución Molecular , Tamaño del Genoma , Genoma Bacteriano , Genómica , Anotación de Secuencia Molecular , Filogenia , Wolbachia/genética , Wolbachia/aislamiento & purificación
3.
PLoS One ; 15(9): e0237802, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32976510

RESUMEN

As availability of precision therapies expands, a well-validated circulating cell-free DNA (cfDNA)-based comprehensive genomic profiling assay has the potential to provide considerable value as a complement to tissue-based testing to ensure potentially life-extending therapies are administered to patients most likely to benefit. Additional data supporting the clinical validity of cfDNA-based testing is necessary to inform optimal use of these assays in the clinic. The FoundationOne®Liquid CDx assay is a pan-cancer cfDNA-based comprehensive genomic profiling assay that was recently approved by FDA. Validation studies included >7,500 tests and >30,000 unique variants across >300 genes and >30 cancer types. Clinical validity results across multiple tumor types are presented. Additionally, results demonstrated a 95% limit of detection of 0.40% variant allele fraction for select substitutions and insertions/deletions, 0.37% variant allele fraction for select rearrangements, 21.7% tumor fraction for copy number amplifications, and 30.4% TF for copy number losses. The limit of detection for microsatellite instability and blood tumor mutational burden were also determined. The false positive variant rate was 0.013% (approximately 1 in 8,000). Reproducibility of variant calling was 99.59%. In comparison with an orthogonal method, an overall positive percent agreement of 96.3% and negative percent agreement of >99.9% was observed. These study results demonstrate that FoundationOne Liquid CDx accurately and reproducibly detects the major types of genomic alterations in addition to complex biomarkers such as microsatellite instability, blood tumor mutational burden, and tumor fraction. Critically, clinical validity data is presented across multiple cancer types.


Asunto(s)
Bioensayo/métodos , Ácidos Nucleicos Libres de Células/genética , Genómica , Neoplasias/genética , Fosfatidilinositol 3-Quinasa Clase I/genética , Receptores ErbB/genética , Exones/genética , Humanos , Límite de Detección , Mutación/genética , Supervivencia sin Progresión , Reproducibilidad de los Resultados
4.
BMC Microbiol ; 20(1): 188, 2020 06 30.
Artículo en Inglés | MEDLINE | ID: mdl-32605600

RESUMEN

BACKGROUND: Wolbachia are the most widely spread endosymbiotic bacteria, present in a wide variety of insects and two families of nematodes. As of now, however, relatively little genomic data has been available. The Wolbachia symbiont can be parasitic, as described for many arthropod systems, an obligate mutualist, as in filarial nematodes or a combination of both in some organisms. They are currently classified into 16 monophyletic lineage groups ("supergroups"). Although the nature of these symbioses remains largely unknown, expanded Wolbachia genomic data will contribute to understanding their diverse symbiotic mechanisms and evolution. RESULTS: This report focuses on Wolbachia infections in three pseudoscorpion species infected by two distinct groups of Wolbachia strains, based upon multi-locus phylogenies. Geogarypus minor harbours wGmin and Chthonius ischnocheles harbours wCisc, both closely related to supergroup H, while Atemnus politus harbours wApol, a member of a novel supergroup S along with Wolbachia from the pseudoscorpion Cordylochernes scorpioides (wCsco). Wolbachia supergroup S is most closely related to Wolbachia supergroups C and F. Using target enrichment by hybridization with Wolbachia-specific biotinylated probes to capture large fragments of Wolbachia DNA, we produced two draft genomes of wApol. Annotation of wApol highlights presence of a biotin operon, which is incomplete in many sequenced Wolbachia genomes. CONCLUSIONS: The present study highlights at least two symbiont acquisition events among pseudoscorpion species. Phylogenomic analysis indicates that the Wolbachia from Atemnus politus (wApol), forms a separate supergroup ("S") with the Wolbachia from Cordylochernes scorpioides (wCsco). Interestingly, the biotin operon, present in wApol, appears to have been horizontally transferred multiple times along Wolbachia evolutionary history.


Asunto(s)
Arácnidos/microbiología , Biotina/genética , Secuenciación Completa del Genoma/métodos , Wolbachia/clasificación , Animales , Transferencia de Gen Horizontal , Tamaño del Genoma , Genoma Bacteriano , Anotación de Secuencia Molecular , Tipificación de Secuencias Multilocus , Operón , Filogenia , Simbiosis , Wolbachia/genética , Wolbachia/aislamiento & purificación
5.
PLoS Pathog ; 16(7): e1008623, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32639986

RESUMEN

Antibiotic treatment has emerged as a promising strategy to sterilize and kill filarial nematodes due to their dependence on their endosymbiotic bacteria, Wolbachia. Several studies have shown that novel and FDA-approved antibiotics are efficacious at depleting the filarial nematodes of their endosymbiont, thus reducing female fecundity. However, it remains unclear if antibiotics can permanently deplete Wolbachia and cause sterility for the lifespan of the adult worms. Concerns about resistance arising from mass drug administration necessitate a careful exploration of potential Wolbachia recrudescence. In the present study, we investigated the long-term effects of the FDA-approved antibiotic, rifampicin, in the Brugia pahangi jird model of infection. Initially, rifampicin treatment depleted Wolbachia in adult worms and simultaneously impaired female worm fecundity. However, during an 8-month washout period, Wolbachia titers rebounded and embryogenesis returned to normal. Genome sequence analyses of Wolbachia revealed that despite the population bottleneck and recovery, no genetic changes occurred that could account for the rebound. Clusters of densely packed Wolbachia within the worm's ovarian tissues were observed by confocal microscopy and remained in worms treated with rifampicin, suggesting that they may serve as privileged sites that allow Wolbachia to persist in worms while treated with antibiotic. To our knowledge, these clusters have not been previously described and may be the source of the Wolbachia rebound.


Asunto(s)
Brugia pahangi/microbiología , Filariasis/microbiología , Filaricidas/farmacología , Rifampin/farmacología , Wolbachia/efectos de los fármacos , Animales , Femenino , Gerbillinae
6.
J Hematol Oncol ; 11(1): 129, 2018 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-30400986

RESUMEN

BACKGROUND: This retrospective study was undertaken to determine if the plasma circulating tumor DNA (ctDNA) level and tumor biological features in patients with advanced solid tumors affected the detection of genomic alterations (GAs) by a plasma ctDNA assay. METHOD: Cell-free DNA (cfDNA) extracted from frozen plasma (N = 35) or fresh whole blood (N = 90) samples were subjected to a 62-gene hybrid capture-based next-generation sequencing assay FoundationACT. Concordance was analyzed for 51 matched FoundationACT and FoundationOne (tissue) cases. The maximum somatic allele frequency (MSAF) was used to estimate the amount of tumor fraction of cfDNA in each sample. The detection of GAs was correlated with the amount of cfDNA, MSAF, total tumor anatomic burden (dimensional sum), and total tumor metabolic burden (SUVmax sum) of the largest ten tumor lesions on PET/CT scans. RESULTS: FoundationACT detected GAs in 69 of 81 (85%) cases with MSAF > 0. Forty-two of 51 (82%) cases had ≥ 1 concordance GAs matched with FoundationOne, and 22 (52%) matched to the National Comprehensive Cancer Network (NCCN)-recommended molecular targets. FoundationACT also detected 8 unique molecular targets, which changed the therapy in 7 (88%) patients who did not have tumor rebiopsy or sufficient tumor DNA for genomic profiling assay. In all samples (N = 81), GAs were detected in plasma cfDNA from cancer patients with high MSAF quantity (P = 0.0006) or high tumor metabolic burden (P = 0.0006) regardless of cfDNA quantity (P = 0.2362). CONCLUSION: This study supports the utility of using plasma-based genomic assays in cancer patients with high plasma MSAF level or high tumor metabolic burden.


Asunto(s)
ADN Tumoral Circulante/genética , Genómica/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
7.
J Mol Diagn ; 20(5): 686-702, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29936259

RESUMEN

Genomic profiling of circulating tumor DNA derived from cell-free DNA (cfDNA) in blood can provide a noninvasive method for detecting genomic biomarkers to guide clinical decision making for cancer patients. We developed a hybrid capture-based next-generation sequencing assay for genomic profiling of circulating tumor DNA from blood (FoundationACT). High-sequencing coverage and molecular barcode-based error detection enabled accurate detection of genomic alterations, including short variants (base substitutions, short insertions/deletions) and genomic re-arrangements at low allele frequencies (AFs), and copy number amplifications. Analytical validation was performed on 2666 reference alterations. The assay achieved >99% overall sensitivity (95% CI, 99.1%-99.4%) for short variants at AF >0.5%, >95% sensitivity (95% CI, 94.2%-95.7%) for AF 0.25% to 0.5%, and 70% sensitivity (95% CI, 68.2%-71.5%) for AF 0.125% to 0.25%. No false positives were detected in 62 samples from healthy volunteers. Genomic alterations detected by FoundationACT demonstrated high concordance with orthogonal assays run on the same clinical cfDNA samples. In 860 routine clinical FoundationACT cases, genomic alterations were detected in cfDNA at comparable frequencies to tissue; for the subset of cases with temporally matched tissue and blood samples, 75% of genomic alterations and 83% of short variant mutations detected in tissue were also detected in cfDNA. On the basis of analytical validation results, FoundationACT has been approved for use in our Clinical Laboratory Improvement Amendments-certified/College of American Pathologists-accredited/New York State-approved laboratory.


Asunto(s)
ADN Tumoral Circulante/genética , Genómica/métodos , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , ADN Tumoral Circulante/sangre , Amplificación de Genes , Dosificación de Gen , Reordenamiento Génico , Humanos , Mutación INDEL/genética
8.
Clin Cancer Res ; 23(2): 379-386, 2017 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-27489289

RESUMEN

PURPOSE: The clinical utility of next-generation sequencing (NGS) in breast cancer has not been demonstrated. We hypothesized that we could perform NGS of a new biopsy from patients with metastatic triple-negative breast cancer (TNBC) in a clinically actionable timeframe. EXPERIMENTAL DESIGN: We planned to enroll 40 patients onto a prospective study, Individualized Molecular Analyses Guide Efforts (IMAGE), to evaluate the feasibility of obtaining a new biopsy of a metastatic site, perform NGS (FoundationOne), and convene a molecular tumor board to formulate treatment recommendations within 28 days. We collected blood at baseline and at time of restaging to assess cell-free circulating plasma tumor DNA (ptDNA). RESULTS: We enrolled 26 women with metastatic TNBC who had received ≥1 line of prior chemotherapy, and 20 (77%) underwent NGS of a metastatic site biopsy. Twelve (60%) evaluable patients received treatment recommendations within 28 days of consent. The study closed after 20 patients underwent NGS, based on protocol-specified interim futility analysis. Three patients went on to receive genomically directed therapies. Twenty-four of 26 patients had genetic alterations successfully detected in ptDNA. Among 5 patients, 4 mutations found in tumor tissues were not identified in blood, and 4 mutations found in blood were not found in corresponding tumors. In 9 patients, NGS of follow-up blood samples showed 100% concordance with baseline blood samples. CONCLUSIONS: This study demonstrates challenges of performing NGS on prospective tissue biopsies in patients with metastatic TNBC within 28 days, while also highlighting the potential use of blood as a more time-efficient and less invasive method of mutational assessment. Clin Cancer Res; 23(2); 379-86. ©2016 AACR.


Asunto(s)
Biomarcadores de Tumor/sangre , ADN de Neoplasias/sangre , Proteínas de Neoplasias/genética , Neoplasias de la Mama Triple Negativas/sangre , Adulto , Anciano , Biopsia , Quimioterapia , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Persona de Mediana Edad , Mutación , Metástasis de la Neoplasia , Proteínas de Neoplasias/biosíntesis , Medicina de Precisión , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/patología
9.
Int J Genomics ; 2016: 9837310, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27774452

RESUMEN

Background. Proper rRNA depletion is crucial for the successful utilization of FFPE specimens when studying gene expression. We performed a study to evaluate two major rRNA depletion methods: Ribo-Zero and RNase H. RNAs extracted from 4 samples were treated with the two rRNA depletion methods in duplicate and sequenced (N = 16). We evaluated their reducibility, ability to detect RNA, and ability to molecularly subtype these triple negative breast cancer specimens. Results. Both rRNA depletion methods produced consistent data between the technical replicates. We found that the RNase H method produced higher quality RNAseq data as compared to the Ribo-Zero method. In addition, we evaluated the RNAseq data generated from the FFPE tissue samples for noncoding RNA, including lncRNA, enhancer/super enhancer RNA, and single nucleotide variation (SNV). We found that the RNase H is more suitable for detecting high-quality, noncoding RNAs as compared to the Ribo-Zero and provided more consistent molecular subtype identification between replicates. Unfortunately, neither method produced reliable SNV data. Conclusions. In conclusion, for FFPE specimens, the RNase H rRNA depletion method performed better than the Ribo-Zero. Neither method generates data sufficient for SNV detection.

10.
Pulm Circ ; 5(1): 135-61, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25992278

RESUMEN

The expression of long noncoding RNAs (lncRNAs) in human heart failure (HF) has not been widely studied. Using RNA sequencing (RNA-Seq), we compared lncRNA expression in 22 explanted human HF hearts with lncRNA expression in 5 unused donor human hearts. We used Cufflinks to identify isoforms and DESeq to identify differentially expressed genes. We identified the noncoding RNAs by cross-reference to Ensembl release 73 (Genome Reference Consortium human genome build 37) and explored possible functional roles using a variety of online tools. In HF hearts, RNA-Seq identified 84,793 total messenger RNA coding and noncoding different transcripts, including 13,019 protein-coding genes, 2,085 total lncRNA genes, and 1,064 pseudogenes. By Ensembl noncoding RNA categories, there were 48 lncRNAs, 27 pseudogenes, and 30 antisense RNAs for a total of 105 differentially expressed lncRNAs in HF hearts. Compared with donor hearts, HF hearts exhibited differential expression of 7.7% of protein-coding genes, 3.7% of lncRNAs (including pseudogenes), and 2.5% of pseudogenes. There were not consistent correlations between antisense lncRNAs and parent genes and between pseudogenes and parent genes, implying differential regulation of expression. Exploratory in silico functional analyses using online tools suggested a variety of possible lncRNA regulatory roles. By providing a comprehensive profile of right ventricular polyadenylated messenger RNA transcriptome in HF, RNA-Seq provides an inventory of differentially expressed lncRNAs, including antisense transcripts and pseudogenes, for future mechanistic study.

11.
Mol Cell ; 58(3): 440-52, 2015 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-25818646

RESUMEN

MYC is an oncoprotein transcription factor that is overexpressed in the majority of malignancies. The oncogenic potential of MYC stems from its ability to bind regulatory sequences in thousands of target genes, which depends on interaction of MYC with its obligate partner, MAX. Here, we show that broad association of MYC with chromatin also depends on interaction with the WD40-repeat protein WDR5. MYC binds WDR5 via an evolutionarily conserved "MYC box IIIb" motif that engages a shallow, hydrophobic cleft on the surface of WDR5. Structure-guided mutations in MYC that disrupt interaction with WDR5 attenuate binding of MYC at ∼80% of its chromosomal locations and disable its ability to promote induced pluripotent stem cell formation and drive tumorigenesis. Our data reveal WDR5 as a key determinant for MYC recruitment to chromatin and uncover a tractable target for the discovery of anticancer therapies against MYC-driven tumors.


Asunto(s)
Carcinogénesis/metabolismo , Cromatina/metabolismo , Proteínas/metabolismo , Proteínas Proto-Oncogénicas c-myc/metabolismo , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Animales , Anisotropía , Sitios de Unión/genética , Carcinogénesis/genética , Cromatina/química , Cromatina/genética , Polarización de Fluorescencia , Células HEK293 , Humanos , Péptidos y Proteínas de Señalización Intracelular , Ratones , Ratones Desnudos , Modelos Moleculares , Datos de Secuencia Molecular , Mutación , Células 3T3 NIH , Unión Proteica , Estructura Terciaria de Proteína , Proteínas/química , Proteínas/genética , Proteínas Proto-Oncogénicas c-myc/química , Proteínas Proto-Oncogénicas c-myc/genética , Homología de Secuencia de Aminoácido , Técnicas del Sistema de Dos Híbridos
12.
Int J Comput Biol Drug Des ; 7(2-3): 102-12, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24878723

RESUMEN

MicroRNAseq (miRNAseq) is a form of RNAseq technology that has become an increasingly popular alternative to miRNA expression profiling. Unlike messenger RNA (mRNA), miRNA extraction can be difficult, and sequencing such small RNA can also be problematic. We designed a study to test the reproducibility of miRNAseq technology and the performance of the two popular miRNA isolation methods, mirVana and TRIzol, by sequencing replicated samples using microRNA isolated with each kit. Through careful analysis of our data, we found excellent repeatability of miRNAseq technology. The mirVana method performed better than TRIzol in terms of useful reads sequenced, number of miRNA identified, and reproducibility. Finally, we identified a baseline noise level for miRNAseq technology; this baseline noise level can be used as a filter in future miRNAseq studies.


Asunto(s)
MicroARNs/química , MicroARNs/aislamiento & purificación , Juego de Reactivos para Diagnóstico , Análisis de Secuencia de ARN/métodos , Humanos , Reproducibilidad de los Resultados
13.
Mitochondrion ; 17: 157-63, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24859348

RESUMEN

Next-generation sequencing, also known as high-throughput sequencing, has greatly enhanced researchers' ability to conduct biomedical research on all levels. Mitochondrial research has also benefitted greatly from high-throughput sequencing; sequencing technology now allows for screening of all 16,569 base pairs of the mitochondrial genome simultaneously for SNPs and low level heteroplasmy and, in some cases, the estimation of mitochondrial DNA copy number. It is important to realize the full potential of high-throughput sequencing for the advancement of mitochondrial research. To this end, we review how high-throughput sequencing has impacted mitochondrial research in the categories of SNPs, low level heteroplasmy, copy number, and structural variants. We also discuss the different types of mitochondrial DNA sequencing and their pros and cons. Based on previous studies conducted by various groups, we provide strategies for processing mitochondrial DNA sequencing data, including assembly, variant calling, and quality control.


Asunto(s)
ADN Mitocondrial/química , ADN Mitocondrial/genética , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Variaciones en el Número de Copia de ADN , Variación Genética , Secuenciación de Nucleótidos de Alto Rendimiento/estadística & datos numéricos , Humanos , Enfermedades Mitocondriales/diagnóstico , Polimorfismo de Nucleótido Simple
14.
Am J Hum Genet ; 94(3): 395-404, 2014 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-24581739

RESUMEN

Genetic association studies of prostate and other cancers have identified a major risk locus at chromosome 8q24. Several independent risk variants at this locus alter transcriptional regulatory elements, but an affected gene and mechanism for cancer predisposition have remained elusive. The retrogene POU5F1B within the locus has a preserved open reading frame encoding a homolog of the master embryonic stem cell transcription factor Oct4. We find that 8q24 risk alleles are expression quantitative trait loci correlated with reduced expression of POU5F1B in prostate tissue and that predicted deleterious POU5F1B missense variants are also associated with risk of transformation. POU5F1 is known to be self-regulated by the encoded Oct4 transcription factor. We further observe that POU5F1 expression is directly correlated with POU5F1B expression. Our results suggest that a pathway critical to self-renewal of embryonic stem cells may also have a role in the origin of cancer.


Asunto(s)
Regulación Neoplásica de la Expresión Génica , Predisposición Genética a la Enfermedad , Factor 3 de Transcripción de Unión a Octámeros/genética , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Adolescente , Adulto , Anciano , Alelos , Estudios de Casos y Controles , Núcleo Celular/metabolismo , Transformación Celular Neoplásica , Bases de Datos Genéticas , Células Madre Embrionarias/citología , Variación Genética , Genotipo , Haplotipos , Humanos , Masculino , Persona de Mediana Edad , Mutación Missense , Sistemas de Lectura Abierta , Sitios de Carácter Cuantitativo , Riesgo , Análisis de Secuencia de ADN , Transcripción Genética , Adulto Joven
15.
J Phys Chem B ; 118(9): 2351-9, 2014 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-24502657

RESUMEN

The development of new sensitive methods for the detailed collection of conformational and morphological information about amyloids is crucial for the elucidation of critical questions regarding aggregation processes in neurodegenerative diseases. The combined approach of two-photon and time-resolved fluorescence spectroscopy described in this report interrogates the early conformational dynamics seen in soluble oligomers of amyloid-ß(1-42). Concentration-dependent aggregation studies using two-photon absorption show enhanced sensitivity toward conformational changes taking place in the secondary structure of the amyloid peptide as aggregation proceeds. Fluorescence lifetimes and changes in anisotropy values indicate Förster-type energy transfer occurring as a function of aggregation state. The sensitivity of our two-photon methodology is compared to that of circular dichroism (CD) spectroscopy, and the results indicate that the two-photon absorption cross-section method exhibits superior sensitivity. A theoretical model is developed that, together with electronic structure calculations, explains the change in cross section as a function of aggregation in terms of interacting transition dipoles for aggregates showing stacked or parallel structures. This suggests that the two-photon method provides a sensitive alternative to CD spectroscopy while avoiding many of the inherent challenges particular to CD data collection. The implication of this finding is significant, as it indicates that a two-photon-based technique used in conjunction with time-resolved fluorescence might be able to reveal answers to conformational questions about amyloid-ß(1-42) that are presently inaccessible with other techniques.


Asunto(s)
Péptidos beta-Amiloides/química , Fragmentos de Péptidos/química , Péptidos beta-Amiloides/metabolismo , Dicroismo Circular , Colorantes Fluorescentes/química , Fragmentos de Péptidos/metabolismo , Fotones , Estructura Secundaria de Proteína , Teoría Cuántica , Espectrometría de Fluorescencia
16.
Cancer Res ; 74(1): 38-43, 2014 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-24247717

RESUMEN

ENOX1 is a highly conserved NADH oxidase that helps to regulate intracellular nicotinamide adenine dinucleotide levels in many cell types, including endothelial cells. Pharmacologic and RNA interference (RNAi)-mediated suppression of ENOX1 impairs surrogate markers of tumor angiogenesis/vasculogenesis, providing support for the concept that ENOX1 represents an antiangiogenic druggable target. However, direct genetic evidence that demonstrates a role for ENOX1 in vascular development is lacking. In this study, we exploited a zebrafish embryonic model of development to address this question. Whole-mount in situ hybridization coupled with immunofluorescence performed on zebrafish embryos demonstrate that enox1 message and translated protein are expressed in most tissues, and its expression is enriched in blood vessels and heart. Morpholino-mediated suppression of Enox1 in Tg(fli1-eGFP) and Tg(flk1-eGFP) zebrafish embryos significantly impairs the development of vasculature and blood circulation. Using in vivo multiphoton microscopy, we show that morpholino-mediated knockdown of enox1 increases NADH levels, consistent with loss of enzyme. VJ115 is a small-molecule inhibitor of Enox1's oxidase activity shown to increase intracellular NADH in endothelial cells; we used VJ115 to determine if the oxidase activity was crucial for vascular development. We found that VJ115 suppressed vasculogenesis in Tg(fli1-eGFP) embryos and impaired circulation. Previously, it was shown that suppression of ENOX1 radiosensitizes proliferating tumor vasculature, a consequence of enhanced endothelial cell apoptosis. Thus, our current findings, coupled with previous research, support the hypothesis that ENOX1 represents a potential cancer therapy target, one that combines molecular targeting with cytotoxic sensitization.


Asunto(s)
Endotelio Vascular/embriología , Endotelio Vascular/crecimiento & desarrollo , Complejos Multienzimáticos/fisiología , NADH NADPH Oxidorreductasas/fisiología , Animales , Animales Modificados Genéticamente , Endotelio Vascular/enzimología , Complejos Multienzimáticos/genética , Complejos Multienzimáticos/metabolismo , NADH NADPH Oxidorreductasas/genética , NADH NADPH Oxidorreductasas/metabolismo , Neovascularización Fisiológica/fisiología , Pez Cebra
17.
Proc Natl Acad Sci U S A ; 111(1): 331-6, 2014 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-24344311

RESUMEN

Basement membrane, a specialized ECM that underlies polarized epithelium of eumetazoans, provides signaling cues that regulate cell behavior and function in tissue genesis and homeostasis. A collagen IV scaffold, a major component, is essential for tissues and dysfunctional in several diseases. Studies of bovine and Drosophila tissues reveal that the scaffold is stabilized by sulfilimine chemical bonds (S = N) that covalently cross-link methionine and hydroxylysine residues at the interface of adjoining triple helical protomers. Peroxidasin, a heme peroxidase embedded in the basement membrane, produces hypohalous acid intermediates that oxidize methionine, forming the sulfilimine cross-link. We explored whether the sulfilimine cross-link is a fundamental requirement in the genesis and evolution of epithelial tissues by determining its occurrence and evolutionary origin in Eumetazoa and its essentiality in zebrafish development; 31 species, spanning 11 major phyla, were investigated for the occurrence of the sulfilimine cross-link by electrophoresis, MS, and multiple sequence alignment of de novo transcriptome and available genomic data for collagen IV and peroxidasin. The results show that the cross-link is conserved throughout Eumetazoa and arose at the divergence of Porifera and Cnidaria over 500 Mya. Also, peroxidasin, the enzyme that forms the bond, is evolutionarily conserved throughout Metazoa. Morpholino knockdown of peroxidasin in zebrafish revealed that the cross-link is essential for organogenesis. Collectively, our findings establish that the triad-a collagen IV scaffold with sulfilimine cross-links, peroxidasin, and hypohalous acids-is a primordial innovation of the ECM essential for organogenesis and tissue evolution.


Asunto(s)
Membrana Basal/metabolismo , Evolución Biológica , Iminas/química , Compuestos de Azufre/química , Secuencia de Aminoácidos , Animales , Colágeno Tipo IV/química , Reactivos de Enlaces Cruzados/química , Drosophila melanogaster , Matriz Extracelular/metabolismo , Proteínas de la Matriz Extracelular/química , Hemo/química , Espectrometría de Masas , Datos de Secuencia Molecular , Péptidos/química , Peroxidasa/química , Peroxidasas/química , Estructura Terciaria de Proteína , Análisis de Secuencia de ARN , Homología de Secuencia de Aminoácido , Pez Cebra , Peroxidasina
18.
Brief Bioinform ; 15(6): 879-89, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24067931

RESUMEN

Advances in next-generation sequencing (NGS) technologies have greatly improved our ability to detect genomic variants for biomedical research. In particular, NGS technologies have been recently applied with great success to the discovery of mutations associated with the growth of various tumours and in rare Mendelian diseases. The advance in NGS technologies has also created significant challenges in bioinformatics. One of the major challenges is quality control of the sequencing data. In this review, we discuss the proper quality control procedures and parameters for Illumina technology-based human DNA re-sequencing at three different stages of sequencing: raw data, alignment and variant calling. Monitoring quality control metrics at each of the three stages of NGS data provides unique and independent evaluations of data quality from differing perspectives. Properly conducting quality control protocols at all three stages and correctly interpreting the quality control results are crucial to ensure a successful and meaningful study.


Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento/normas , Análisis de Secuencia de ADN/normas , Biología Computacional/normas , ADN/genética , Biblioteca de Genes , Secuenciación de Nucleótidos de Alto Rendimiento/estadística & datos numéricos , Humanos , Neoplasias/genética , Polimorfismo de Nucleótido Simple , Control de Calidad , Alineación de Secuencia/normas , Alineación de Secuencia/estadística & datos numéricos , Análisis de Secuencia de ADN/estadística & datos numéricos
19.
J Phys Chem B ; 117(50): 15935-42, 2013 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-24245815

RESUMEN

We report detailed photophysical studies on the two-photon fluorescence processes of the solvatochromic fluorophore 4-DMN as a conjugate of the calmodulin (CaM) and the associated CaM-binding peptide M13. Strong two-photon fluorescence enhancement has been observed which is associated with calcium binding. It is found that the two-photon absorption cross-section is strongly dependent on the local environment surrounding the 4-DMN fluorophore in the CaM conjugates, providing sensitivity between sites of fluorophore attachment. Utilizing time-resolved measurements, the emission dynamics of 4-DMN under various environmental (solvent) conditions are analyzed. In addition, anisotropy measurements reveal that the 4-DMN-S38C-CaM system has restricted rotation in the calcium-bound calmodulin. To establish the utility for cellular imaging, two-photon fluorescence microscopy studies were also carried out with the 4-DMN-modified M13 peptide in cells. Together, these studies provide strong evidence that 4-DMN is a useful probe in two-photon imaging, with advantageous properties for cellular experiments.


Asunto(s)
Péptidos/química , Ftalimidas/química , Proteínas/química , Espectrometría de Fluorescencia/métodos , Fotones
20.
Trends Genet ; 29(10): 593-9, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23972387

RESUMEN

Exome sequencing is one of the most cost-efficient sequencing approaches for conducting genome research on coding regions. However, significant portions of the reads obtained in exome sequencing come from outside of the designed target regions. These additional reads are generally ignored, potentially wasting an important source of genomic data. There are three major types of unintentionally sequenced read that can be found in exome sequencing data: reads in introns and intergenic regions, reads in the mitochondrial genome, and reads originating in viral genomes. All of these can be used for reliable data mining, extending the utility of exome sequencing. Large-scale exome sequencing data repositories, such as The Cancer Genome Atlas (TCGA), the 1000 Genomes Project, National Heart, Lung, and Blood Institute (NHLBI) Exome Sequencing Project, and The Sequence Reads Archive, provide researchers with excellent secondary data-mining opportunities to study genomic data beyond the intended target regions.


Asunto(s)
Bases de Datos de Ácidos Nucleicos , Exoma/genética , Análisis de Secuencia de ADN , ADN/genética , Genoma Mitocondrial , Humanos , Polimorfismo de Nucleótido Simple
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