NIH Scientist Discover Protein Which Plays Key Role in Skin's Natural Protection From UV

Researchers have identified a protein that plays an important, early role in the increase of protective skin pigmentation after exposure to ultraviolet (UV) radiation. The National Institute of Health discovery is the first to show that a protein in the SOX family can be regulated by UV radiation. The results appear in the August 13, 2007, Proceedings of the National Academy of Sciences.

Melanin is a pigment produced in the skin that helps protect cells from cancer-causing UV rays. Specialized cells called melanocytes produce the melanin, which is then transported to other epidermal cells (called keratinocytes) that make up the majority of the skin. Melanoma, a cancer of melanocytes, is the most deadly of the skin cancers, and its incidence is rising in the United States.

UV radiation from the sun or other sources, such as tanning parlors, can cause many types of damage to the skin and has been associated with a process that leads to many types of skin cancers. Individuals with lighter skin incur greater damage from UV and thus have significantly higher risk for skin cancer.

“Increased pigmentation of the skin from UV is thought to help minimize the damage from UV,” said NCI Director John E. Niederhuber, M.D. “This research on SOX9 not only gives us important insights into the intricate mechanism our body uses to protect itself from ultraviolet rays, but also into cellular pathways that might contribute to the origins and spread of melanoma.”

They found that levels of SOX9 increased within two hours after UV exposure, and continued to increase until eight hours after exposure.

“The most novel part of this study was the fact that we identified a new transcription factor that may be the earliest responder to stimulation of pigmentation such as seen in the tanning reaction following UV exposure,” said Vincent Hearing, Ph.D., chief of the NCI’s Center for Cancer Research’s (CCR) Pigment Cell Biology Section and senior author of the study. “SOX9 is likely one of the first factors that’s activated to start the chain of events that eventually leads to increases in skin pigmentation.”

Hearing’s laboratory is now examining SOX9 to see whether it could be used to target melanoma.

Adapted from Aug. 14 NIH news release