Discoveries
'Guardian' protein found to underlie skin tanning
A protein known as the "master watchman of the genome" because it helps guard against cancercausing DNA damage also carries out an entirely separate and vital function, Dana-Farber scientists have found. By prompting the skin to tan in response to ultraviolet light from the sun, the protein – called p53 – stands at the head of a molecular pathway of major importance in determining the risk of developing skin cancer. Melanoma, the most deadly form of skin cancer, is also the most rapidly increasing type of cancer in the world.
Not only that, but p53 may also play a role in people's seemingly universal desire to be in the sun – an intriguing discovery that may help explain certain behavioral aspects of skin cancer risk.
The findings fill a gap in scientists' knowledge of the basic mechanism by which skin tans, and raise the possibility that creams or lotions that trigger the tanning process without a need for ultraviolet radiation exposure could offer a way of reducing melanoma risk in some people.
"A major risk factor for melanoma is an inability to tan; people who naturally tan easily or have dark pigmentation are far less likely to develop the disease," says David E. Fisher, MD, PhD, director of the Melanoma Program at Dana-Farber and a professor of pediatric hematology/oncology at Harvard Medical School, who led the study with Rutao Cui, MD, PhD. "This study suggests that p53, one of the best-known tumor-suppressor proteins in our body, plays a powerful role in controlling the skin's protective mechanisms against sun damage."
Importantly, Fisher adds, "These studies in no way suggest that artificial ultraviolet tanning strategies such as indoor tanning salons are safe. Indeed, ultraviolet radiation is a known carcinogen [cancer-causer] and should be avoided."
