Extrachromosomal circular DNA: a new potential role in cancer progression

Tianyi Wang,Jiahai Shi,Haijian Zhang,Youlang Zhou

doi:10.1186/s12967-021-02927-x

Abstract

Extrachromosomal circular DNA (eccDNA) is considered a circular DNA molecule that exists widely in nature and is independent of conventional chromosomes. eccDNA can be divided into small polydispersed circular DNA (spcDNA), telomeric circles (t-circles), microDNA, and extrachromosomal DNA (ecDNA) according to its size and sequence. Multiple studies have shown that eccDNA is the product of genomic instability, has rich and important biological functions, and is involved in the occurrence of many diseases, including cancer. In this review, we focus on the discovery history, formation process, characteristics, and physiological functions of eccDNAs; the potential functions of various eccDNAs in human cancer; and the research methods employed to study eccDNA.

Highlights

As a type of DNA molecule, circular DNA is ubiquitous in nature and includes bacterial plasmids as well as some viral genomes [1–3]
There are no definitive research findings that show the specific functions of small polydispersed circular DNA (spcDNA), telomeric circles and microDNA, we are able to use the limited knowledge that is currently available to make the following inferences: spcDNA can enhance genomic instability and lead to cell carcinogenesis.; telomeric circles can constantly repair telomeres and affect cell proliferation and cell cycle progression; and microDNA affects cell gene expression by regulation of small RNA, which leads to cell carcinogenesis
As a DNA molecule independent of chromosomes, Extrachromosomal circular DNA (eccDNA) undoubtedly has a greater advantage over small RNAs: eccDNA theoretically has a longer half-life, a more stable biological structure, and can carry more genetic information, so more information can be transmitted in intercellular communication

Summary

Introduction

As a type of DNA molecule, circular DNA is ubiquitous in nature and includes bacterial plasmids as well as some viral genomes [1–3]. MicroDNA containing exon sequences inhibits endogenous genes derived from microDNA by forming new si-like RNAs. Extrachromosomal DNA (ecDNA) As early as 1965, DMs were first found in metaphase neuroblastoma cells [5] and subsequently in various types of cancer [54–58].

Results

Conclusion