Fair skin is associated with
increased risk of skin cancer. However, recent animal studies reveal that
factors other than UV radiations are involved in increasing the risk of
melanoma in fair-skinned people with red hair.
Dr. David Fisher, chief of
dermatology at Massachusetts General Hospital in Boston and his team had
previously experimented with genetically modified mice and found that mice with pheomelanin, pigment responsible for red hair,
still had high incidence of melanoma even in the absence of UV radiations.
This finding prompted the
researchers to look further into the chemical mechanisms involved with
pheomelanin in inducing cancer.
Researchers analyzed the
biochemical reactions involved in the synthesis of pheomelanin and found two
possible mechanisms, which could trigger cancer. Pheomelanin was found to promote the formation of reactive oxygen
species, resulting in oxidative stress on the cells and DNA damage which in
turn could lead to formation of cancer cells.
It was also noted that
pheomelanin synthesis required cysteine, a protein found in many cells.
Scientists suspect that this could deplete the cysteine-based antioxidants from
the cells, thus making the cells prone to carcinogenesis.
Authors note that these two
mechanisms may be dependent on each other and require further studies to
identify the exact mechanisms involved in cancer triggering process of
pheomelanin. It could immensely help fair skinned and red haired people in
taking the correct precautionary steps in preventing skin cancer.
Researchers conclude that these
findings might help in better understanding melanoma and developing preventive
treatments. Meanwhile the authors encourage fair skinned with red hair to have
themselves checked frequently for melanoma and avoid high exposure to sun. Reference:
Two distinct mechanisms could
explain the carcinogenicity of pheomelanin synthesis:Ann M. Morgan*, Jennifer Lo, David E. Fisher:DOI: