Why Redheads Burn: Gene Receptor Linked to Red Hair and Melanoma

Why are redheads more likely to burn? It all hinges on a certain gene receptor. Scientists have discovered that the melanocortin-1 (MC1R) gene receptor is responsible for both red hair and also promotes an important cancer-causing pathway. The new findings show exactly why people with red hair also tend to be more at risk for develping melanoma.

Redheads have a well-known risk of developing melanoma, the least common but most lethal of skin cancers. Accounting for about 75 percent of skin cancer deaths, melanoma originates in pigment-producing skin cells called melanocytes. It's thought to be a multi-step process of genetic mutations that increase cell proliferation, differentiation and death. Needless to say, learning what might cause melanoma could help prevent its development.

In order to examine melanoma a bit more closely, the researchers embarked on a series of experiments in both mouse models and cell cultures. They found that under normal circumstances, MC1R was binding to PTEN, a well-known tumor suppressor gene. In fact, PTEN acted as a safeguard against cancer; without it, though, the end result was elevated signaling in the cancer-causing P13K/Akt pathway.

So what does this have to do with redheads? It turns out that people with red hair have MC1R-RHC mutations. These mutations lack the protective PTEN mechanism.

"As a result, upon UVB exposure we saw an increased destruction of PTEN in the mutated pigment cells," said Wenyi Wei, the senior author of the new study, in a news release.

That's not all they found. The researchers also discovered that in these same MC1R-RHC pigment cells, elevated P13K/Akt activity was boosting cell proliferation and was synchronizing with another well-known cancer mutation in the BRAF gene, which is found in nearly 70 percent of human melanomas.

The findings reveal exactly why redheads are at increased risk of developing melanoma. In fact, scientists discovered that they have a 10 to 100-fold higher frequency of melanoma. Yet the findings don't just show that redheads are at risk; they also may lead to a starting point for future studies that could use these mutations as markers to find out who might be at increased risk of developing melanoma. This could lead to preventative measures that could help keep patients healthy.

The findings are published in the journal Molecular Cell.