Department of Medicine, Laboratory of Pharmacology, Medical School, Democritus University of Thrace, Alexandroupolis, Greece.
Department of Oncology, Medical School, Democritus University of Thrace, Alexandroupolis, Greece.
J Cell Physiol. 2019 Aug;234(8):14079-14089. doi: 10.1002/jcp.28097. Epub 2019 Jan 7.
Circulating cell-free DNA (ccfDNA) is a biological entity of great interest due to its potential as liquid biopsy biomaterial carrying clinically valuable information. To better understand its nature, we studied ccfDNA in vitro in two human cancer cell lines MCF-7 and HeLa. Normalized indexes of ccfDNA per cell population decreased over time of culture but were significantly elevated after exposure to IC doses of the demethylating/apoptotic agent 5-azacytidine (5-AZA-CR). Fragment-size profiling was indicative of active release, whereas exposure to 5-AZA-CR induced the release of additional shorter fragments, indicative of apoptosis. Finally, the methylation profile of a panel of cancer-specific genes as assessed by quantitative methylation analysis in ccfDNA was identical to the corresponding genomic DNA and followed accurately changes caused by 5-AZA-CR. Overall, our in vitro findings support that ccfDNA can be a reliable biosource of clinically relevant information that can be further studied in these cell culture models.
循环无细胞 DNA（ccfDNA）是一种非常有趣的生物实体，因为它有可能作为携带临床有价值信息的液体活检生物材料。为了更好地了解其性质，我们在两种人类癌细胞系 MCF-7 和 HeLa 中对 ccfDNA 进行了体外研究。培养过程中，每个细胞群体的 ccfDNA 标准化指数随时间降低，但在暴露于低剂量的去甲基化/凋亡剂 5-氮杂胞苷（5-AZA-CR）后，显著升高。片段大小分析表明其为活跃释放，而暴露于 5-AZA-CR 会诱导释放更多较短的片段，表明细胞凋亡。最后，通过定量甲基化分析在 ccfDNA 中评估了一组癌症特异性基因的甲基化谱，与相应的基因组 DNA 相同，并准确地反映了 5-AZA-CR 引起的变化。总的来说，我们的体外研究结果支持 ccfDNA 可以作为临床相关信息的可靠生物来源，并且可以在这些细胞培养模型中进一步研究。
