It's not always fun in the sun. Dermatologists warn that not even the best sunscreens prevent all the potentially cancer-causing damage that ultraviolet light (UV) does to skin. A new study, however, suggests that incorporating certain snippets of DNA into sunscreens could prompt skin to repair UV-induced genetic damage before it leads to cancer. Indeed, scientists have found that slathering such DNA fragments onto UV-exposed hairless mice thwarts skin cancer.
The investigators speculate that the DNA bits mimic chromosome damage in the skin cells that pick them up, and thereby tell the cells to boost their DNA-repair activity. "We think we've tapped into a very important signaling pathway," says Barbara Gilchrest of Boston University School of Medicine.
When ultraviolet light hits an unprotected skin cell, it can damage the cell's DNA. That may lead to a long-lasting mutation, if the cell doesn't quickly repair the molecular lesions.
Tanning is another way the ski