Biomaterial Database

Discoveries of Extrachromosomal Circles of DNA in Normal and Tumor Cells. 2018

Teressa Paulsen, and Pankaj Kumar, and M Murat Koseoglu, and Anindya Dutta

Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA.

While the vast majority of cellular DNA in eukaryotes is contained in long linear strands in chromosomes, we have long recognized some exceptions like mitochondrial DNA, plasmids in yeasts, and double minutes (DMs) in cancer cells where the DNA is present in extrachromosomal circles. In addition, specialized extrachromosomal circles of DNA (eccDNA) have been noted to arise from repetitive genomic sequences like telomeric DNA or rDNA. Recently eccDNA arising from unique (nonrepetitive) DNA have been discovered in normal and malignant cells, raising interesting questions about their biogenesis, function and clinical utility. Here, we review recent results and future directions of inquiry on these new forms of eccDNA.

UI	MeSH Term	Description	Entries
D009360	Neoplastic Cells, Circulating	Exfoliate neoplastic cells circulating in the blood and associated with metastasizing tumors.	Circulating Neoplastic Cells,Embolic Tumor Cells,Embolism, Tumor,Neoplasm Circulating Cells,Tumor Cells, Embolic,Cells, Neoplasm Circulating,Circulating Cells, Neoplasm,Circulating Tumor Cells,Cell, Circulating Neoplastic,Cell, Circulating Tumor,Cell, Embolic Tumor,Cell, Neoplasm Circulating,Cells, Circulating Neoplastic,Cells, Circulating Tumor,Cells, Embolic Tumor,Circulating Neoplastic Cell,Circulating Tumor Cell,Embolic Tumor Cell,Embolisms, Tumor,Neoplasm Circulating Cell,Neoplastic Cell, Circulating,Tumor Cell, Circulating,Tumor Cell, Embolic,Tumor Cells, Circulating,Tumor Embolism,Tumor Embolisms
D009369	Neoplasms	New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.	Benign Neoplasm,Cancer,Malignant Neoplasm,Tumor,Tumors,Benign Neoplasms,Malignancy,Malignant Neoplasms,Neoplasia,Neoplasm,Neoplasms, Benign,Cancers,Malignancies,Neoplasias,Neoplasm, Benign,Neoplasm, Malignant,Neoplasms, Malignant
D010944	Plants	Multicellular, eukaryotic life forms of kingdom Plantae. Plants acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations. It is a non-taxonomical term most often referring to LAND PLANTS. In broad sense it includes RHODOPHYTA and GLAUCOPHYTA along with VIRIDIPLANTAE.	Plant
D010957	Plasmids	Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.	Episomes,Episome,Plasmid
D002877	Chromosomes, Human	Very long DNA molecules and associated proteins, HISTONES, and non-histone chromosomal proteins (CHROMOSOMAL PROTEINS, NON-HISTONE). Normally 46 chromosomes, including two sex chromosomes are found in the nucleus of human cells. They carry the hereditary information of the individual.	Chromosome, Human,Human Chromosome,Human Chromosomes
D004270	DNA, Circular	Any of the covalently closed DNA molecules found in bacteria, many viruses, mitochondria, plastids, and plasmids. Small, polydisperse circular DNA's have also been observed in a number of eukaryotic organisms and are suggested to have homology with chromosomal DNA and the capacity to be inserted into, and excised from, chromosomal DNA. It is a fragment of DNA formed by a process of looping out and deletion, containing a constant region of the mu heavy chain and the 3'-part of the mu switch region. Circular DNA is a normal product of rearrangement among gene segments encoding the variable regions of immunoglobulin light and heavy chains, as well as the T-cell receptor. (Riger et al., Glossary of Genetics, 5th ed & Segen, Dictionary of Modern Medicine, 1992)	Circular DNA,Circular DNAs,DNAs, Circular
D004272	DNA, Mitochondrial	Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.	Mitochondrial DNA,mtDNA
D004273	DNA, Neoplasm	DNA present in neoplastic tissue.	Neoplasm DNA
D005057	Eukaryotic Cells	Cells of the higher organisms, containing a true nucleus bounded by a nuclear membrane.	Cell, Eukaryotic,Cells, Eukaryotic,Eukaryotic Cell
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man