It's long been known that people with naturally red hair also have a higher risk of the skin cancer melanoma, and now scientists might have uncovered why.
Researchers from Beth Israel Deaconess Medical Center and Boston University School of Medicine found that the same genetic mutation that gives a person red hair -- a mutation on the melanocortin-1 (MC1R) gene receptor -- also seems to play a role in the development of cancer.
When a person with red hair is exposed to UV radiation, this gene mutation seems to promote a signaling pathway known to play a role in cancer development. The signaling pathway, called PI3K/Akt, has been linked with other cancers, including lung, ovarian and breast.
The study, published in the journal Molecular Cell, is based on work on cell cultures and mice. Normally, the MC1R gene receptor binds to a tumor-suppressing gene called PTEN, which stops increased signaling to the cancer-linked PI3K/Akt pathway. However, for people with red hair with the MC1R gene mutation, the MC1R gene receptor doesn't seem to have this protective mechanism against cancer.
Plus, researchers found that the increased activity of the PI3K/Akt signaling pathway seemed to increase cell proliferation and was also interacting with a gene mutation known to play a role in most cases of melanoma.
"Together, our findings provide a possible molecular mechanism as to why red-haired individuals harboring MC1R mutations are much more susceptible to UV-induced skin damage than individuals with darker skin, resulting in a 10- to 100-fold higher frequency of melanoma," study researcher Wenyi Wei, Ph.D., an investigator in the Department of Pathology at Beth Israel Deaconess and an associate professor of pathology at Harvard Medical School, said in a statement.
A recent study conducted in mice and published in the journal BioEssays speculated that people with red hair may have a higher melanoma risk because of the actual red hair pigment produced by their bodies. HealthDay reported that the pigment, called pheomelanin, might increase cells' vulnerability to DNA damage.