Last-Minute Rescue: How Cells Cut Dangerous DNA Bridges to Prevent Cancer.

A team of researchers from the Ulsan National Institute of Science and Technology (UNIST) and the Institute for Basic Science (IBS) has discovered the precise molecular mechanism by which cells remove DNA bridges that threaten genomic stability during division. Their findings reveal how the enzyme LEM-3 acts as a last-resort tool to sever persistent DNA connections between chromosomes, helping to prevent errors that can lead to cancer.

Led by Professor Anton Gartner, Distinguished Professor at the UNIST Graduate School of Medicine and Associate Faculty of the IBS Center for Genomic Integrity, alongside IBS Research Fellow Stephane Rolland, the study sheds light on a crucial safeguard in the final moments of cytokinesis—the stage where two daughter cells separate.

Cell division is essential for maintaining tissue health, with billions of cells in the human body dividing daily. However, when DNA replication is incomplete or chromosomes become entangled, DNA bridges can form between dividing cells. If left unresolved, these bridges may cause chromosome missegregation, loss of genetic information, and eventually, tumor formation.

The researchers previously identified LEM-3 as a key player in resolving such bridges, especially when other DNA repair systems fail. LEM-3 accumulates at the midbody—the structure linking the two daughter cells—and functions as a nuclease, an enzyme that cuts DNA. In this study, the team explored LEM-3’s substrate recognition, DNA-cutting activity, and the role of its structural domains in directing it to the right location at the right time.

Their experiments in the model organism Caenorhabditis elegans revealed that while LEM-3 is vital for DNA bridge resolution, its activity must be tightly controlled. A mutant version of the protein that entered the nucleus caused unintended DNA damage, leading to embryo death. This highlights the importance of spatial regulation in LEM-3’s function.

LEM-3’s human counterpart, ANKLE1, has been associated with certain cancers, including breast and colorectal cancer. As Professor Gartner noted, these insights may offer new avenues for therapeutic strategies aimed at preventing or treating cancer by targeting DNA bridge resolution pathways.

This breakthrough underscores the intricate checks and balances cells employ to maintain genetic integrity—and how a single misstep in this tightly choreographed process can have serious consequences.

Source:https://www.sciencedaily.com/releases/2025/05/250519131805.html

This is non-financial/medical advice and made using AI so could be wrong.