Damaged DNA Travels Between Human Cells via Nanotubes

Damaged DNA can move from one human cell to another through thin tube-like structures called tunneling nanotubes, according to a study published May 19 in Cell. Researchers at the Children’s Medical Center Research Institute at UT Southwestern in Dallas mixed two types of cells in the lab and induced genome damage.

They observed DNA fragments traveling along the nanotubes and reaching neighboring cells. The transferred DNA carried functional traits. In one test, an antibiotic-resistance gene from male cells moved to female cells.

Tunneling nanotubes are known structures that connect living cells and allow transport of materials such as mitochondria. Until this study, DNA had not been observed moving along these pathways. Cancer cells have previously used nanotubes to exchange mitochondria with neighboring cells.

Cancer biologist Paul Mischel of Stanford University called the findings an important and exciting discovery. Cancer cell biologist Peter Ly said the work raises questions about whether tumors could spread harmful mutations through this mechanism. Physician-scientist Christoph Gerdes of Princess Margaret Cancer Centre noted that fragments conferring chemotherapy resistance might move between cells, though it is too early to confirm this occurs.

Geneticist Buket Basmanav of the University of Bonn said the study provides strong evidence that DNA transfer occurs via nanotubes and connects earlier observations. Peter Ly stated that researchers still need to determine how often the transfer happens and whether it can be detected in different tumor types.