Seeing Is Believing: Intercellular Transfer of DNA between Human Cells

Genomic insults in the form of DNA damage and mitotic errors can result in mislocalization of nuclear DNA into the cytoplasm in the form of micronuclei or as fragmented chromosomal elements. Recent work from the Ly lab has demonstrated that cytoplasmic DNAs can undergo intercellular transfer via nanotube-like connections. Using a variety of cell lines, the authors demonstrate the transfer of DNA through nanotubes and that various sources of genome instability can promote this phenomenon. Crucially, the transferred DNA can be incorporated into the nucleus of recipient cells and intermix with host chromosomes. Additionally, the transferred DNA molecules are functional and can provide a fitness advantage to recipient cells. These findings uncover a novel horizontal gene transfer mechanism in human cells, which could have profound implications in human disease and biology.