Causes and consequences of micronuclei

Curr Opin Cell Biol. 2021 Jun;70:91-99. doi: 10.1016/j.ceb.2021.01.004. Epub 2021 Feb 18.

Abstract

Micronuclei are small membrane-bounded compartments with a DNA content encapsulated by a nuclear envelope and spatially separated from the primary nucleus. Micronuclei have long been linked to chromosome instability, genome rearrangements, and mutagenesis. They are frequently found in cancers, during senescence, and after genotoxic stress. Compromised integrity of the micronuclear envelope delays or disrupts DNA replication, inhibits DNA repair, and exposes micronuclear DNA directly to cytoplasm. Micronuclei play a central role in tumorigenesis, with micronuclear DNA being a source of complex genome rearrangements (including chromothripsis) and promoting a cyclic GMP-AMP synthase (cGAS)-mediated cellular immune response that may contribute to cancer metastasis. Here, we discuss recent findings on how micronuclei are generated, what the consequences are, and what cellular mechanisms can be applied to protect against micronucleation.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Chromothripsis*
  • DNA Damage
  • Genomic Instability
  • Humans
  • Micronuclei, Chromosome-Defective*
  • Nuclear Envelope