학술논문

Circular ecDNA promotes accessible chromatin and high oncogene expression
Document Type
article
Source
Nature. 575(7784)
Subject
Biological Sciences
Genetics
Human Genome
Cancer
Biotechnology
Cancer Genomics
Cell Line
Tumor
Chromatin
DNA
Circular
Gene Expression Regulation
Neoplastic
Humans
Microscopy
Electron
Scanning
Neoplasms
Oncogenes
General Science & Technology
Language
Abstract
Oncogenes are commonly amplified on particles of extrachromosomal DNA (ecDNA) in cancer1,2, but our understanding of the structure of ecDNA and its effect on gene regulation is limited. Here, by integrating ultrastructural imaging, long-range optical mapping and computational analysis of whole-genome sequencing, we demonstrate the structure of circular ecDNA. Pan-cancer analyses reveal that oncogenes encoded on ecDNA are among the most highly expressed genes in the transcriptome of the tumours, linking increased copy number with high transcription levels. Quantitative assessment of the chromatin state reveals that although ecDNA is packaged into chromatin with intact domain structure, it lacks higher-order compaction that is typical of chromosomes and displays significantly enhanced chromatin accessibility. Furthermore, ecDNA is shown to have a significantly greater number of ultra-long-range interactions with active chromatin, which provides insight into how the structure of circular ecDNA affects oncogene function, and connects ecDNA biology with modern cancer genomics and epigenetics.