Extrachromosomal DNA amplifications in cancer

In this Review, the authors discuss our latest understanding of extrachromosomal DNA (ecDNA), a type of circular DNA element commonly found in cancers. They discuss ecDNA properties, including oncogene amplifications and transcriptional hub formation, as well as opportunities for therapeutic interventions. Extrachromosomal DNA (ecDNA) amplification is an important driver alteration in cancer. It has been observed in most cancer types and is associated with worse patient outcome. The functional impact of ecDNA has been linked to its unique properties, such as its circular structure that is associated with altered chromatinization and epigenetic regulatory landscape, as well as its ability to randomly segregate during cell division, which fuels intercellular copy number heterogeneity. Recent investigations suggest that ecDNA is structurally more complex than previously anticipated and that it localizes to specialized nuclear bodies (hubs) and can act in trans as an enhancer for genes on other ecDNAs or chromosomes. In this Review, we synthesize what is currently known about how ecDNA is generated and how its genetic and epigenetic architecture affects proto-oncogene deregulation in cancer. We discuss how recently identified ecDNA functions may impact oncogenesis but also serve as new therapeutic vulnerabilities in cancer.

Automated summary

This review discusses the latest understanding of extrachromosomal DNA (ecDNA) in cancers, including its properties and role in oncogenesis. The amplification of ecDNA is common in cancer and associated with worse patient outcomes. Recent studies have revealed the complex structure and functions of ecDNA, including its ability to act as an enhancer for genes on other ecDNAs or chromosomes. This knowledge opens up new opportunities for therapeutic interventions in cancer.