New insight into skin-tanning process suggests novel way of preventing skin cancer

Findings from a study led by researchers at Dana-Farber Cancer Institute and Children’s Hospital Boston have rewritten science’s understanding of the process of skin tanning – an insight that has enabled them to develop a promising way of protecting fair- skinned people from skin cancer caused by exposure to sunlight.

The study, published in the journal Nature’s Sept. 21, 2006, issue, involved giving tans to specially engineered mice, not by exposing them to ultraviolet rays in sunlight (the usual route to a tan), but by applying a cream that switched on the tanning machinery in their skin cells. Because people who tan easily, or have naturally dark skin, are far less likely to develop skin cancer than fair-skinned individuals – who tend to get sunburns rather than tan – the findings suggests that medicinally-induced tans can protect at-risk individuals from the disease.

“The study involved using a small molecule to essentially mimic the process that occurs when skin cells are struck by ultraviolet light from the sun,” says the study’s senior author, David E. Fisher, MD, PhD, director of the Melanoma Program at Dana- Farber and a professor in pediatrics at Children’s Hospital Boston. While the compound used in the study has not yet been tested in humans, the results “demonstrate the principle that actual tanning can be ‘rescued’ by recognizing the normal pathway and the precise step where it is blocked in people who do not tan well,” he remarks.

The study was supported by grants from the National Institutes of Health, the Doris Duke Charitable Foundation, and the Japanese Ministry of Education, Culture, Sports, and Technology. Fisher is the Jan and Charles Nirenberg Fellow in Pediatric Oncology at Dana-Farber.