APR 08, 2019 08:54 AM PDT

A Cellular Mechanism for Repairing DNA Damage is Revealed

WRITTEN BY: Carmen Leitch

The cells in our body must constantly be renewed. Every time, the DNA in a cell has to be duplicated and distributed evenly between its daughter cells (the cell cycle is illustrated in the video). All that replicating is bound to introduce some errors into the genome. We are also exposed to environmental factors like carcinogens that can cause such damage. As those errors build up, it can eventually lead to serious health problems like cancer. But our cells also have natural ways to repair those damaging errors. Now, scientists at the University of Copenhagen have identified one such process, which allows human cells to stop picking up new mutations as they replicate. Special proteins surround the damaged DNA, shielding it until it can be repaired. The findings have been reported in Nature Cell Biology

“We have discovered a specific mechanism in human cells that delay propagation of DNA damage in successive generations of dividing cells. This discovery helps us understand how our bodies protect themselves from many types of cancer,” explained Professor Jiri Lukas, Head of the Chromosome Stability and Dynamics Group and Executive Director of the Novo Nordisk Foundation Center for Protein Research at the University of Copenhagen.

In previous work, Lukas’ group has found that tiny structures called 53BP1 nuclear bodies protect DNA from damage caused during replication. In this study, they fluorescently labeled the 53BP1 nuclear bodies within human cells over generations. That enabled them to observe damaged DNA in mother cells as it moved to daughter cells. 

Through this meticulous effort, the researchers found that daughter cells can send their 53BP1 nuclear bodies to the site of inherited DNA lesions. Thus, they get a chance to repair inherited genetic errors. It seems that an enzyme called RAD52 is a crucial player in this process as well; as a member of a tumor-suppressing family, it guards against genetic mutations that can lead to cancer.

"53BP1 nuclear bodies delay cell division in daughter cells in order to reach the only remaining time in their lifecycle when they can mend DNA lesions that their mother caused but could not fix. This second chance is vital because it is also the last one. We have predicted and then experimentally documented that a failure of this second chance converts the initially curable DNA damage to one that can no longer be fixed. Accumulation of such mishaps could lead to disease, including cancer," said Assistant Professor Kai John Neelsen of the Novo Nordisk Foundation Center for Protein Research.

Image credit: Max Pixel

This work could help in the development of new cancer therapeutics. Cancer drugs often disrupt the rapid cell division that’s typical of cancer growth, so the timing of DNA repair must be considered when creating new drugs and attempting to minimize side effects from treatments that are already in use.

“Our work reveals unexpected ways in which cells deal with inherited DNA damage. With the identification of the key proteins driving this process, we have laid the foundation for investigations into potential therapeutic applications,” said postdoctoral fellow Julian Spies of the Novo Nordisk Foundation Center for Protein Research at the University of Copenhagen.


Sources: AAAS/Eurekalert! via University of Copenhagen the Faculty of Health and Medical Sciences, Nature Cell Biology

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
MAR 11, 2019
Microbiology
MAR 11, 2019
How Different Strains of Bacteria Impact Acne
The microbe Propionibacterium acnes has long been thought to be the cause of acne, but it can be found on everyone's skin....
MAR 20, 2019
Genetics & Genomics
MAR 20, 2019
Analyzing Genomic Data in the Field
Researchers found a way to cut down on the computational power it requires to analyze genetic data. Now portable mini-sequencers have more applications....
MAR 26, 2019
Genetics & Genomics
MAR 26, 2019
Utilizing CRISPR Technology for Digital Detection of Genetic Material
Graphene has long been known for its semiconductor capabilities and now it's being put to work in biosensors. Kiana Aran, Ph.D., Co-Founder of Nanosens, Assistant Professor of Biomedical...
APR 23, 2019
Genetics & Genomics
APR 23, 2019
Controlling Gene Expression with Light
Researchers are developing multiple ways to turn genes off and on with light....
APR 26, 2019
Microbiology
APR 26, 2019
Massive Survey Reveals Nearly 200,000 New Marine Viral Species
After a global survey of the world's oceans, an international team of researchers has found almost 200,000 new species of marine viruses....
MAY 07, 2019
Cancer
MAY 07, 2019
Why Breast Surgeons Are Calling for Wider Genetic Testing
In early 2019, the American Society of Breast Surgeons (ASBrS) released new recommendations on genetic testing for people with breast cancer, widening the ...
Loading Comments...