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Clinical Chemistry and Laboratory... Jan 2024Cancer morbidity and mortality can be reduced if the cancer is detected early. Cell-free DNA (cfDNA) fragmentomics emerged as a novel epigenetic biomarker for early...
OBJECTIVES
Cancer morbidity and mortality can be reduced if the cancer is detected early. Cell-free DNA (cfDNA) fragmentomics emerged as a novel epigenetic biomarker for early cancer detection, however, it is still at its infancy and requires technical improvement. We sought to apply a single-strand DNA sequencing technology, for measuring genetic and fragmentomic features of cfDNA and evaluate the performance in detecting multiple cancers.
METHODS
Blood samples of 364 patients from six cancer types (colorectal, esophageal, gastric, liver, lung, and ovarian cancers) and 675 healthy individuals were included in this study. Circulating tumor DNA mutations, cfDNA fragmentomic features and a set of protein biomarkers were assayed. Sensitivity and specificity were reported by cancer types and stages.
RESULTS
Circular Ligation Amplification and sequencing (CLAmp-seq), a single-strand DNA sequencing technology, yielded a population of ultra-short fragments (<100 bp) than double-strand DNA preparation protocols and reveals a more significant size difference between cancer and healthy cfDNA fragments (25.84 bp vs. 16.05 bp). Analysis of the subnucleosomal peaks in ultra-short cfDNA fragments indicates that these peaks are regulatory element "footprints" and correlates with gene expression and cancer stages. At 98 % specificity, a prediction model using ctDNA mutations alone showed an overall sensitivity of 46 %; sensitivity reaches 60 % when protein is added, sensitivity further increases to 66 % when fragmentomics is also integrated. More improvements observed for samples representing earlier cancer stages than later ones.
CONCLUSIONS
These results suggest synergistic properties of protein, genetic and fragmentomics features in the identification of early-stage cancers.
Topics: Humans; Cell-Free Nucleic Acids; Early Detection of Cancer; Mutation; Circulating Tumor DNA; Neoplasms; Biomarkers, Tumor
PubMed: 37678194
DOI: 10.1515/cclm-2023-0541 -
Journal of Molecular Cell Biology Feb 2021Ever since gene targeting or specific modification of genome sequences in mice was achieved in the early 1980s, the reverse genetic approach of precise editing of any... (Review)
Review
Ever since gene targeting or specific modification of genome sequences in mice was achieved in the early 1980s, the reverse genetic approach of precise editing of any genomic locus has greatly accelerated biomedical research and biotechnology development. In particular, the recent development of the CRISPR/Cas9 system has greatly expedited genetic dissection of 3D genomes. CRISPR gene-editing outcomes result from targeted genome cleavage by ectopic bacterial Cas9 nuclease followed by presumed random ligations via the host double-strand break repair machineries. Recent studies revealed, however, that the CRISPR genome-editing system is precise and predictable because of cohesive Cas9 cleavage of targeting DNA. Here, we synthesize the current understanding of CRISPR DNA fragment-editing mechanisms and recent progress in predictable outcomes from precise genetic engineering of 3D genomes. Specifically, we first briefly describe historical genetic studies leading to CRISPR and 3D genome engineering. We then summarize different types of chromosomal rearrangements by DNA fragment editing. Finally, we review significant progress from precise 1D gene editing toward predictable 3D genome engineering and synthetic biology. The exciting and rapid advances in this emerging field provide new opportunities and challenges to understand or digest 3D genomes.
Topics: Animals; CRISPR-Cas Systems; DNA; Gene Editing; Genetic Engineering; Genome; Humans; Imaging, Three-Dimensional
PubMed: 33125070
DOI: 10.1093/jmcb/mjaa060 -
Progress in Biophysics and Molecular... Mar 2015Eukaryotic DNA ligases seal DNA breaks in the final step of DNA replication and repair transactions via a three-step reaction mechanism that can abort if DNA ligases... (Review)
Review
Eukaryotic DNA ligases seal DNA breaks in the final step of DNA replication and repair transactions via a three-step reaction mechanism that can abort if DNA ligases encounter modified DNA termini, such as the products and repair intermediates of DNA oxidation, alkylation, or the aberrant incorporation of ribonucleotides into genomic DNA. Such abortive DNA ligation reactions act as molecular checkpoint for DNA damage and create 5'-adenylated nucleic acid termini in the context of DNA and RNA-DNA substrates in DNA single strand break repair (SSBR) and ribonucleotide excision repair (RER). Aprataxin (APTX), a protein altered in the heritable neurological disorder Ataxia with Oculomotor Apraxia 1 (AOA1), acts as a DNA ligase "proofreader" to directly reverse AMP-modified nucleic acid termini in DNA- and RNA-DNA damage responses. Herein, we survey APTX function and the emerging cell biological, structural and biochemical data that has established a molecular foundation for understanding the APTX mediated deadenylation reaction, and is providing insights into the molecular bases of APTX deficiency in AOA1.
Topics: Animals; Binding Sites; DNA; DNA Damage; DNA Repair; DNA-Binding Proteins; Exoribonucleases; Humans; Models, Chemical; Models, Molecular; Nuclear Proteins; Protein Binding; RNA; Spinocerebellar Ataxias; Structure-Activity Relationship
PubMed: 25637650
DOI: 10.1016/j.pbiomolbio.2015.01.007 -
Journal of Molecular Biology May 2019DNA ligases are a highly conserved group of nucleic acid enzymes that play an essential role in DNA repair, replication, and recombination. This review focuses on... (Review)
Review
DNA ligases are a highly conserved group of nucleic acid enzymes that play an essential role in DNA repair, replication, and recombination. This review focuses on functional interaction between DNA polymerases and DNA ligases in the repair of single- and double-strand DNA breaks, and discusses the notion that the substrate channeling during DNA polymerase-mediated nucleotide insertion coupled to DNA ligation could be a mechanism to minimize the release of potentially mutagenic repair intermediates. Evidence suggesting that DNA ligases are essential for cell viability includes the fact that defects or insufficiency in DNA ligase are casually linked to genome instability. In the future, it may be possible to develop small molecule inhibitors of mammalian DNA ligases and/or their functional protein partners that potentiate the effects of chemotherapeutic compounds and improve cancer treatment outcomes.
Topics: Animals; DNA; DNA Breaks; DNA Ligases; DNA Repair; DNA-Directed DNA Polymerase; Genomic Instability; Humans; Protein Interaction Maps
PubMed: 31034893
DOI: 10.1016/j.jmb.2019.04.028 -
BioTechniques Sep 2015The demand for cloned genes has increased incessantly over the past 32 years, but some who need recombinant plasmids struggle to produce them. While the pitfalls of... (Review)
Review
The demand for cloned genes has increased incessantly over the past 32 years, but some who need recombinant plasmids struggle to produce them. While the pitfalls of traditional ligation-dependent cloning are non-trivial, most can be avoided with sufficient effort and attention to detail. Here, the chemical properties of enzymes and reagents used to clone genes into plasmids are reviewed to draw attention to the most pertinent details. In particular, the virtues of agarose gel electrophoresis monitoring, the nature of the interactions between DNA and silica, and challenges associated with thermostable DNA polymerases, restriction endonucleases, and T4 DNA ligase are explored. Common pitfalls associated with Escherichia coli transformation and DNA modifying enzymes are also described. A thorough understanding of established methods is essential for troubleshooting, implementing alternative approaches, and inventing new techniques in response to changes in technology and demand.
Topics: Cloning, Molecular; DNA; DNA Ligases; DNA Restriction Enzymes; Electrophoresis, Agar Gel; Enzymes; Equipment Design; Escherichia coli; Molecular Biology; Polymerase Chain Reaction
PubMed: 26345511
DOI: 10.2144/000114324 -
Journal of Visualized Experiments : JoVE Jan 2023Chromosome conformation capture (3C) is used to detect three-dimensional chromatin interactions. Typically, chemical crosslinking with formaldehyde (FA) is used to fix...
Chromosome conformation capture (3C) is used to detect three-dimensional chromatin interactions. Typically, chemical crosslinking with formaldehyde (FA) is used to fix chromatin interactions. Then, chromatin digestion with a restriction enzyme and subsequent religation of fragment ends converts three-dimensional (3D) proximity into unique ligation products. Finally, after reversal of crosslinks, protein removal, and DNA isolation, DNA is sheared and prepared for high-throughput sequencing. The frequency of proximity ligation of pairs of loci is a measure of the frequency of their colocalization in three-dimensional space in a cell population. A sequenced Hi-C library provides genome-wide information on interaction frequencies between all pairs of loci. The resolution and precision of Hi-C relies on efficient crosslinking that maintains chromatin contacts and frequent and uniform fragmentation of the chromatin. This paper describes an improved in situ Hi-C protocol, Hi-C 3.0, that increases the efficiency of crosslinking by combining two crosslinkers (formaldehyde [FA] and disuccinimidyl glutarate [DSG]), followed by finer digestion using two restriction enzymes (DpnII and DdeI). Hi-C 3.0 is a single protocol for the accurate quantification of genome folding features at smaller scales such as loops and topologically associating domains (TADs), as well as features at larger nucleus-wide scales such as compartments.
Topics: Chromosomes; Chromatin; DNA; Cell Nucleus; DNA Restriction Enzymes; Formaldehyde; Nucleic Acid Conformation
PubMed: 36744801
DOI: 10.3791/64001 -
Structure (London, England : 1993) Mar 2022DNA ligases act in the final step of many DNA repair pathways and are commonly regulated by the DNA sliding clamp proliferating cell nuclear antigen (PCNA), but there...
DNA ligases act in the final step of many DNA repair pathways and are commonly regulated by the DNA sliding clamp proliferating cell nuclear antigen (PCNA), but there are limited insights into the physical basis for this regulation. Here, we use single-particle cryoelectron microscopy (cryo-EM) to analyze an archaeal DNA ligase and heterotrimeric PCNA in complex with a single-strand DNA break. The cryo-EM structures highlight a continuous DNA-binding surface formed between DNA ligase and PCNA that supports the distorted conformation of the DNA break undergoing repair and contributes to PCNA stimulation of DNA ligation. DNA ligase is conformationally flexible within the complex, with its domains fully ordered only when encircling the repaired DNA to form a stacked ring structure with PCNA. The structures highlight DNA ligase structural transitions while docked on PCNA, changes in DNA conformation during ligation, and the potential for DNA ligase domains to regulate PCNA accessibility to other repair factors.
Topics: Cryoelectron Microscopy; DNA; DNA Ligase ATP; DNA Ligases; DNA Replication; Nucleic Acid Conformation; Proliferating Cell Nuclear Antigen; Protein Binding
PubMed: 34838188
DOI: 10.1016/j.str.2021.11.002 -
Nucleic Acids Research May 2022DNA ligases, critical enzymes for in vivo genome maintenance and modern molecular biology, catalyze the joining of adjacent 3'-OH and 5'-phosphorylated ends in DNA. To...
DNA ligases, critical enzymes for in vivo genome maintenance and modern molecular biology, catalyze the joining of adjacent 3'-OH and 5'-phosphorylated ends in DNA. To determine whether DNA annealing equilibria or properties intrinsic to the DNA ligase enzyme impact end-joining ligation outcomes, we used a highly multiplexed, sequencing-based assay to profile mismatch discrimination and sequence bias for several ligases capable of efficient end-joining. Our data reveal a spectrum of fidelity and bias, influenced by both the strength of overhang annealing as well as sequence preferences and mismatch tolerances that vary both in degree and kind between ligases. For example, while T7 DNA ligase shows a strong preference for ligating high GC sequences, other ligases show little GC-dependent bias, with human DNA Ligase 3 showing almost none. Similarly, mismatch tolerance varies widely among ligases, and while all ligases tested were most permissive of G:T mismatches, some ligases also tolerated bulkier purine:purine mismatches. These comprehensive fidelity and bias profiles provide insight into the biology of end-joining reactions and highlight the importance of ligase choice in application design.
Topics: DNA; DNA Ligases; Humans; Purines
PubMed: 35438779
DOI: 10.1093/nar/gkac241 -
Sheng Wu Gong Cheng Xue Bao = Chinese... May 2024To develop an accurate and efficient protocol for multi-fragment assembly and multi-site mutagenesis, we integrated and optimized the common multi-fragment assembly...
To develop an accurate and efficient protocol for multi-fragment assembly and multi-site mutagenesis, we integrated and optimized the common multi-fragment assembly methods and validated the established method by using fructose-1,6-diphosphatase 1 (FBP1) with 4 mutant sites. The fragments containing mutations were assembled by introducing mutant sites and I recognition sequences. After digestion/ligation, the ligated fragment was amplified with the primers containing overlap region to the linearized vector. The amplified fragment was ligated to the linearized vector and the ligation product was transformed into . After screening and sequencing, the recombinant plasmid with 4 mutant sites was obtained. This protocol overcame the major defects of Gibson assembly and Golden Gate assembly, serving as an efficient solution for multi-fragment assembly and multi-site mutagenesis.
Topics: Escherichia coli; Fructose-Bisphosphatase; Homologous Recombination; Plasmids; Genetic Vectors; DNA; Mutation; Mutagenesis, Site-Directed; Cloning, Molecular
PubMed: 38783816
DOI: 10.13345/j.cjb.230793 -
Scientific Reports Mar 2018Most members of the poly(ADP-ribose)polymerase family, PARP family, have a catalytic activity that involves the transfer of ADP-ribose from a beta-NAD+-molecule to...
Most members of the poly(ADP-ribose)polymerase family, PARP family, have a catalytic activity that involves the transfer of ADP-ribose from a beta-NAD+-molecule to protein acceptors. It was recently discovered by Talhaoui et al. that DNA-dependent PARP1 and PARP2 can also modify DNA. Here, we demonstrate that DNA-dependent PARP3 can modify DNA and form a specific primed structure for further use by the repair proteins. We demonstrated that gapped DNA that was ADP-ribosylated by PARP3 could be ligated to double-stranded DNA by DNA ligases. Moreover, this ADP-ribosylated DNA could serve as a primed DNA substrate for PAR chain elongation by the purified proteins PARP1 and PARP2 as well as by cell-free extracts. We suggest that this ADP-ribose modification can be involved in cellular pathways that are important for cell survival in the process of double-strand break formation.
Topics: Cell Cycle Proteins; Cell-Free System; DNA; DNA Breaks, Double-Stranded; Humans; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerases
PubMed: 29520010
DOI: 10.1038/s41598-018-22673-3