Department of Chemistry

 Researchers, including chemists at the University of California, Riverside, have found that the type of skin pigment predominantly found in red-haired, fair-skinned individuals may itself contribute to the development of melanoma, suggesting that blocking UV radiation, which continues to be essential, may not be enough.

Several types of the pigment melanin are found in the skin — such as a dark brown or black form predominant in individuals with dark hair or skin, and a lighter blond-to-red pigment predominant in individuals with red hair, freckles and fair skin. Red/blond melanin is known to be less effective than dark melanin in shielding against UV damage.

Led by scientists at the Massachusetts General Hospital, the research team performed lab experiments, in the absence of any UV radiation, on strains of mice that were nearly identical genetically except for the gene that controls the type of pigment melanin produced.

When the researchers genetically disabled all pigment production in a group of red hair/fair skinned mice, they found that something about the pigment itself, and not other aspects of being red-haired and fair-skinned, was leading to melanoma.

Study results appeared online in Nature on Oct. 31.  A description of the study can be found here.

“Our results suggest that the red/yellow pigmentation pathway may contribute to UV-independent melanoma development in the group of red hair/fair skinned mice by a mechanism involving oxidative damage — the process by which reactive oxygen species damage cells,” said Yinsheng Wang, a professor of chemistry at UC Riverside whose lab was involved in the research. “Our contribution to the research, which provides a key line of evidence to support the research paper’s central hypothesis, lies in the quantitative measurement of the level of oxidative DNA damage in mouse skin tissues.”

The UCR component of the research was supported by a grant to Wang from the National Cancer Institute of the National Institutes of Health.  Besides Wang, Jin Wang, a former postdoctoral fellow, and Candace Guerrero, a graduate student, are UCR coauthors on the research paper.

Next the UCR researchers plan to work with the Massachusetts General Hospital researchers to assess how antioxidant treatment affects melanoma development in red hair/fair skinned mice.