Table 1 Characteristics of ecDNA

Extrachromosomal small circular DNA

eccDNA

Single or double

< 1 Mb. invisible under microscope

Telomere circle, spcDNA, miDNA, episome

Small regulatory RNA

tumurgenic through selective teleomeric extension, modifying geneome stability

[9, 66, 71, 107]

Extrachromosomal DNA (double minutes)

ecDNA

Double

1–3 Mb, visible under microscope

BFB cycle, translocation/deletion amplification, episome and chromothripsis

Oncogene amplification, regulatory regions, no centromeres or telomeres

Oncogene amplification, chromosome, rearrangement Gene fusions, epigenetic/Histone, modification, nucleosome accessibility, signaling pathways regulation intra-tumoral heterogeneity autophagy, metastasis and invasiveness, senescence antitumor immunity

[1, 9, 25, 108]