The dark side of circulating nucleic acids

Abstract

SummaryFree circulating or cell‐free DNA (cfDNA), possibly from dying cells that release their contents into the blood as they break down, have become of major interest as a source for noninvasive diagnostics. Recent work demonstrated the uptake of human cfDNA in mouse cells in vitro and in vivo, accompanied by the activation of a cellular DNA damage response (DDR) and the appearance of apoptotic proteins in the host cells. By acting as a source of mobile genetic elements, cfDNA could be a continuous source of DNA mutagenesis of healthy cells in the body throughout life, promoting progressive cellular aging in vivo. As such, cfDNA may causally contribute to multiple aging‐related diseases, such as cancer, diabetes, and Alzheimer's disease.

Circulating cell-free DNA, telomere length and bilirubin in the Vienna Active Ageing Study: exploratory analysis of a randomized, controlled trial

“…From the 105 individuals that complied to the initially established inclusion criteria1527, we additionally excluded 4 individuals with increased reference values of liver enzymes (ALT, AST or GGT). Increased liver enzymes were important indicators for liver abnormality which might influence bilirubin levels, a key variable in this analysis.…”

“…Dying and dead cells release their content extracellularly, and a portion of the genomic DNA can be found circulating in the bloodstream before final excretion as a waste product14. A recent review15 suggests the possibility of cell-free genomic-derived DNA (cfDNA) integration into the genome of living cells, leading further to increased genome instability.…”

Exploring the unmapped DNA and RNA reads in a songbird genome

“…Illustrative, especially in human genome studies, are several misattributions of horizontal gene transfer events [53,54]. Integration of foreign DNA released by dead cells into healthy host cells is also possible [55,56]. Nothing is known about horizontal gene transfer in the great tit and in our BLAST results we did not find any contig that was partially mapped to bird and partially mapped to a non-vertebrate species.…”

Determination of Viral Nucleic Acid in the Human Blood

“…Одной из важнейших проблем, с которой столкнулись исследователи, является загрязнение образцов нецелевыми нуклеиновыми кислотами. Прежде всего это относится к ДНК хозяина, попадающей в кровь в результате распада лейкоцитов или перманентно присутствующей в плазме крови (так называемая циркулирующая внеклеточная ДНК [25]). Последовательности ДНК хозяина легко могут быть опознаны и удалены при биоинформатической обработке данных, полученных при секвенировании, но при малых количествах вирионов в крови присутствие ДНК хозяина может существенно снизить объем данных по вирусным нуклеиновым кислотам.…”