Each year some 1.3 million cases of skin cancer are diagnosed in the United States.
Unfortunately, the only way to protect yourself right now is by slathering on sunscreen or
covering exposed skin. But scientists are working to develop improved "morning after"
treatments to repair sun-damaged skin before it turns cancerous, and some recent research by
Notre Dame Professor of Chemistry Olaf Wiest and his colleagues may significantly help that
effort.
For some time it's been known that excessive ultraviolet light can alter skin cell DNA.
Molecules called thymine dimers, which have been implicated in skin cancer, are formed in
DNA when exposed to UV light.
However, Wiest and his colleagues have been able to synthesize a certain molecule that
attaches to these dimers, chemically breaking them down and thus repairing DNA damage. The
Wiest lab's molecule mimics the action of photolyase, a naturally occurring enzyme in algae and
certain other organisms that repairs light-induced DNA damage
In addition to the "repair molecule," the Wiest research group also has discovered a new,
easier way to detect the repair happening. During the process, certain molecules rotate or flip to
the outside of the DNA helix. Recently Wiest and his colleague, Lauren O'Neil, synthesized a
novel molecule that binds to the so-called "flipped out" base and then signals its presence by
emitting light energy, which can be detected by ultrasensitive sensors.
(January 2007)
