SEP 14, 2016 6:17 AM PDT

Scientists Uncover a Molecular Pac-Man that May Fight Cancer

WRITTEN BY: Xuan Pham
In researching how the breast clears out cells after the milk supply is finished, scientists at the University of Sheffield have inadvertently identified a protein that may help curb cancer growth. The protein of interest appears to gobble up nearby dead cells to prevent inflammation, kind of like a molecular Pac-Man.


 "It is thought that we shed the equivalent of our own body weight in dead cells every year," said Nasreen Ahktar, professor at the Sheffield’s Department of Oncology and Metabolism. But where do these cells go? How does the body get rid of them?
 
To answer this puzzle, Ahktar and his team focused on the breast, which is well known to undergo major changes before, during, and after lactation. In particular, when the job of producing milk is finished, the breast alveoli cells revert back to pre-pregnancy state. In studying this process, Ahktar and his team discovered a protein named Rac1.
 
Rac1 is apparently important for both stimulating the alveoli cells to secrete milk, but it is also vital in cell removal after the milk dries up. The Rac1 signal seems to tell cells to “eat” neighboring cells that are dead or dying. This clears up cellular debris and promotes renewal.
 
"By doing the job themselves, the breast epithelia limit both the numbers and time of immune phagocyte infiltration which protects the tissue from becoming damaged,” said Ahktar. "Without Rac1, the dead cells and milk flood the interconnecting breast ducts causing them to bloat and triggering chronic inflammation. The bloated ducts then fail to regenerate and produce milk in a future pregnancy."
 

While the results are significant in the field of developmental biology, Ahktar’s team is hopeful that this process can be applied to cancer biology. If in normal cells, Rac1 promotes cellular phagocytosis and reduce inflammation, how do cancer cells use (or abuse) Rac1? And more importantly, can scientists tame this protein and direct it against cancer? Answering these questions and more may provide a therapeutic target for curbing cancer’s growth.
 
But first, scientists have to contend with a contradiction. "Rac1 is over expressed in various cancers including breast cancer and Rac1 inhibitors are currently being considered as anticancer therapies,” said Ahktar. By contrast, Ahktar’s findings seem to suggest blocking Rac1 would be a bad idea.  
 
In particular, Ahktar said, "… in the breast, one of [Rac1’s] central roles is to prevent harmful inflammatory responses. Without Rac1 these responses are heightened and prolonged within tissues.”
 
The results underscore the need for further research into understanding the mechanism behind this molecular Pac-Man.
 
Additional source: The University of Sheffield
About the Author
  • I am a human geneticist, passionate about telling stories to make science more engaging and approachable. Find more of my writing at the Hopkins BioMedical Odyssey blog and at TheGeneTwist.com.
You May Also Like
NOV 20, 2019
Clinical & Molecular DX
NOV 20, 2019
New diagnostic technology seeks out cancer DNA in blood
For many cancers, early detection has a tremendous impact on patient outcomes. Yet, sadly, many of the most common malignancies, like those of the stomach,...
NOV 18, 2019
Cancer
NOV 18, 2019
UV light targets hyperhotspots for skin cancer
New research published in Proceedings of the National Academy of Sciences suggests that certain “hyperhotspots” in the human genome can be pinp...
DEC 18, 2019
Genetics & Genomics
DEC 18, 2019
Learning More About The Genetic Adaptations Cancer Relies On
Cancer cells can adapt to mutations in the genome that might kill the cells by altering the activity of their genes....
DEC 24, 2019
Cancer
DEC 24, 2019
The effect of aspirin on breast cancer
New research published recently in the journal Cancer aims to better understand the effects that aspirin can have on breast cancer. Previous research has s...
JAN 05, 2020
Cancer
JAN 05, 2020
What does obesity have to do with skin cancer?
You might not think that obesity has anything at all to do with skin cancer. Yes, obesity has been linked as a clear risk factor to other cancers, but&hell...
FEB 10, 2020
Immunology
FEB 10, 2020
How Cancer Evades the Immune System Time and Time Again
Scientists discovered a new mechanism by which cancer cells evade the immune system to further their own agenda: invade, multiply, and spread. Identifying...
Loading Comments...