"Ultraviolet B light damages a certain kind of RNA that does not make proteins in a cell. This damage leads to the release of inflammatory chemicals called cytokines. It's all part of the process of removing damaged cells so they can be replaced with new, healthy ones. The sunburn response itself is produced by the immune system, which targets damaged cells for destruction.
The cytokine response has major implications for tumor formation. Damaged skin cells that aren't removed can lead to skin cancer.
The response to damaged RNA could possibly be used to mimic the effect of sunlight, which is used to treat the skin disease psoriasis. In the case of psoriasis, the approach could involve introducing damaged RNA similar to that produced by sunburn, mimicking the reaction without the carcinogenic dangers of sunlight.
The inflammatory response is important to start the process of healing after cell death. The inflammatory process may clean up cells with genetic damage before they can become cancer.
Better sunscreens could be developed by using the amount of RNA damage as a measure of the severity of sunburn. The better the sunscreen, the less RNA damage."
By investigator Richard L. Gallo, MD, PhD, professor of medicine at UC San Diego School of Medicine and Veterans Affairs San Diego Healthcare System.