What's Burning in a Sunburn?

Skin cancer and inflammation explored

(RxWiki News) If you're light-skinned, you probably know what a sunburn is - you turn red, it's tender to the touch or flat out painful. It's a drag. So what causes all this? Scientists may now know.

When we sunburn, the immune system is working to repair the damage produced by a powerful foe -  ultraviolet (UV) radiation. Sunburns damage skin cell RNA - a sister of DNA that's in charge of cell activities.

"Wear sunscreen when outside."

Understanding this may lead to new therapies to block inflammation, something that would have a huge impact on medicine. Inflammation is at the heart of many, many diseases including cancer.

These are the findings of researchers at the University of California, San Diego School of Medicine and elsewhere. The team was led by principal investigator Richard L.Gallo, MD, PhD, professor of medicine at UCSD School of Medicine and Veterans Affairs San Diego Healthcare System.

For this pre-clinical study, investigators worked with a mouse model and with human skin cells.

What the team found is that UVB radiation does extreme damage to a particular type of RNA. This altered RNA is released and the immune system responds to get rid of the sun-damaged cells.

This is the sunburn process that we see and feel.

“The inflammatory response is important to start the process of healing after cell death,” said Dr. Gallo.

He goes on to say, “We also believe the inflammatory process may clean up cells with genetic damage before they can become cancer. Of course, this process is imperfect and with more UV exposure, there is more chance of cells becoming cancerous.”

The role of other factors such as gender, pigmentation and an individual's own genetics still need to be explored.

“Genetics is closely linked to the ability to defend against UV damage and develop skin cancers,” Dr. Gallo said.

“We know in our mouse genetic models that specific genes will change how the mice get sunburn. Humans have similar genes, but it is not known if people have mutations in these genes that affect their sun response.”

This work was published in the July 8, 2012 Advance Online Publication of Nature Medicine.

No funding information was provided; the authors declared no conflicts of interest.


Reviewed by: 
Review Date: 
July 10, 2012