Study suggests that targeted drugs can induce a protective tan

A recent study by researchers at Dana-Farber Cancer Institute and Children's Hospital Boston has raised the possibility that scientists may be able to develop an effective means of protecting fair-skinned people from skin cancer caused by exposure to sunlight. The research involved "tanning" specially engineered red-haired, light-skinned mice by applying a cream that activated their skin cells' tanning mechanism. Although the tan-inducing compound used on the mice has not yet been tested in humans, the findings suggest that medicinally induced tanning likely can occur in people who do not normally tan well and are, therefore, deprived of a tan's protective qualities.

The researchers' objective was to study melanoma in mice whose fair skin stemmed from the same genetic roots as the skin of fair-skinned humans. The team found that, although tanning could not be induced in fair-skinned mice by exposure to ultraviolet rays (instead, they developed a sunburn), tanning could be induced when the mice were treated with specific, targeted drugs.

Investigators treated the fair-skinned mice with a compound, forskolin, that is known to increase the body's levels of the physiologic molecule cyclic adenosine monophosphate (cAMP). Treated mice turned dark, proving that melanocytes in fair-skinned mice-and, perhaps, in fair-skinned humans-are not inherently unable to produce pigment if they are appropriately stimulated. Further experimentation showed that red-haired mice treated with forskolin developed a tan that was virtually indistinguishable from the natural tan of dark-haired mice.

The study was published in the September 21, 2006, issue of Nature.