PULLMAN, Wash. — The risk of getting skin cancer from tanning beds or sunbathing appears to be much worse than many think. Scientists at Washington State University say exposure to ultraviolet (UV) light triggers multiple mutations.
The study finds exposure to DNA-damaging ultraviolet light used in tanning beds could cause malignant melanoma, the deadliest form of skin cancer. Their research also discovered a single intense dose to ultraviolet-B radiation, coming in sunlight, is enough to cause abnormal mutations.
While UV light has been linked to skin cancer for some time, researchers are still learning about how damaging it can be. UV light is a form of electromagnetic radiation, which comes from the sun and man-made sources like tanning beds.
“There’s been this debate: how much does UV light cause the mutations that actually cause the cancer? Our research supports that UV light plays a major role in producing mutations specific to the growth and spread of melanoma,” says study co-author professor John Wyrick, of the university’s College of Veterinary Medicine, in a university release.
Research ‘could help identify causes of severe skin cancers’
UV light from the sun or tanning lamps damages human DNA, producing mutations, which can trigger cancerous growths. The same is true in baker’s yeast, making it an “excellent” guinea pig to study how dangerous these mutations are.
Researchers irradiated 150 yeast colonies with UV lamps 15 times for eight seconds over the course of a month. Genome sequencing then helped to identify an estimated 50,000 mutations in the yeast cells’ DNA. The study finds about half the mutations in the irradiated cells are rare mutations with a link to melanoma.
Genetic information is stored in our DNA as a code made up of four chemicals, which are also called bases. While UV damage was thought to be limited to only two DNA bases — C (cytosine) or T (thymine) — some damage was observed in A (adenine) bases.
“This has a lot of real-world applications and could help identify causes of severe skin cancers,” says co-author undergraduate student Haley Morris.
Malignant melanoma, the deadliest form of skin cancer, is expected to cause 6,850 people to die in 2020, according to the American Cancer Society. The first sign of melanoma is often a new mole or a change in the appearance of an existing mole. If it’s caught early, melanoma can be treated with surgery, otherwise radiotherapy or immunotherapy can help slow the cancer spreading.
The findings, published in the journal Cell Reports, raise important questions surrounding the safety of tanning, be it in a sun-bed or outdoors.
SWNS writer Tom Campbell contributed to this report.