Spontaneous release of DNA by human blood lymphocytes as shown in an in vitro system.

作者：Philippe Anker, Maurice Stroun, Pierre A. Maurice · 发表于：PubMed · 年份：1975 · 被引用次数：236 · 研究领域：Molecular Biology Techniques and Applications、Carcinogens and Genotoxicity Assessment、RNA Interference and Gene Delivery

Human blood lymphocytes released DNA in vitro in the absence of any stimulation. Once purified from the complex appearing in the supernatant, this DNA exhibited typical characteristics as shown by its UV absorption curve, its deoxyribose coloration, and its sensitivity to DNase. Elution patterns on hydroxyapatite columns indicated that the excreted DNA is double stranded. The released DNA was smaller than the cellular DNA; its molecular weight ranged from 3.5 x 10(5) to 3.7 x 10(6) daltons. The DNA appearing in the supernatant does not seem to be due to dead or dying cells since: (a) the same amount of DNA was found in the medium whether the incubation lasted 2 hr or as long as 16 hr; (b) cell death rate had no effect on the amount of extracellular DNA; (c) when the lymphocytes were centrifuged and placed in a new medium several times in a row, a similar amount of extracellular DNA was isolated from each of the successive supernatants, whereas if, after centrifugation, the lymphocytes were put back in their original medium, no increase in the amount of extracellular DNA was observed, suggesting an active regulatory mechanism independent of a mechanical effect; (d) it took more than 1 hr for extracellular DNA to reach its maximum concentration, a fact that also argues against a mechanical effect; (e) the specific activity of the released DNA was different from that of the cellular DNA, depending on the time of labeling; and (f) the cells that had excreted DNA kept their functi...