From: Novel insights into extrachromosomal DNA: redefining the onco-drivers of tumor progression
Model | Mechanism | Reference |
---|---|---|
Episome | Replication bubble drop from the chromosome to produce an episome and then the episome replicates and recombines to form ecDNA. | |
Translocation-excision-deletion-amplification | Two chromosomes translocate with subsequent excision and deletion at the regions neighboring translocation breakpoints, and then the separate fragments amplify and circularize to form ecDNA. | [56] |
Chromothripsis | Chromosomes are isolated into fragments through an error in cell segregation, and the fragments connect randomly to produce ecDNA. | |
A multistep evolutionary process | The single-chromosome ancestral episomes undergo a series of discrete mutation events, including recombinations, deletions and duplications to produce various ecDNAs. |