In the current study, published online in Nature on January 19, , the researchers set out to determine what changes take place when melanocytes are exposed to UV radiation. The scientists developed mice whose melanocytes expressed a green fluorescent protein. The cells could then be easily tracked in the mouse and purified from the skin.
The team exposed the mice to levels of UV radiation that would normally cause sunburn in people. They saw greater numbers of melanocytes in the skin afterward, and the cells migrated toward the outer skin layer. Analysis of the cells showed that they expressed a set of genes known to respond to a protein called interferon-gamma IFN-g. These changes did not occur when the researchers blocked IFN-g in the mice, suggesting that this protein is involved in activating melanocytes upon exposure to UV radiation.
The scientists figured out that the IFN-g came from immune cells called macrophages, which entered the skin upon UV exposure. When the team mixed these UV-elicited macrophages with melanoma cells and transplanted them into mouse skin, they saw increased growth of tumors. The increased tumor growth also disappeared when the researchers blocked IFN-g. Find out the best ways to enjoy the sun safely. Melanoma skin cancer can grow down through the layers of the skin and spread to other parts of the body.
Remember, when skin cancer is found at an early stage, treatment is more likely to be successful. Read more about melanoma skin cancer symptoms. Brown, K. Dennis, L. Sunburns and risk of cutaneous melanoma, does age matter: a comprehensive meta-analysis. Ann Epidemiol. Skip to main content. How does the sun and UV cause cancer? Too much ultraviolet UV radiation from the sun can damage DNA in your skin cells and cause skin cancer.
In the UK almost 9 in 10 cases of melanoma, the most serious type of skin cancer, could be prevented by staying safe in the sun and avoiding sunbeds. Getting sunburnt just once every two years can triple your risk of melanoma skin cancer, compared to never being burnt. What is UV? Damage from UV exposure is cumulative and increases your skin cancer risk over time. The unrepaired damage builds up over time and triggers mutations that cause skin cells to multiply rapidly.
That can lead to malignant tumors. The degree of damage depends on the intensity of UV rays and the length of time your skin has been exposed without protection. Location is also a factor. If you live where the sun is strong year-round, your exposure level and risk increases.
You can easily reduce your likelihood of developing skin cancer by taking care to protect yourself against UV radiation. UVB facts and risks. UVB penetrates and damages the outermost layers of your skin. Overexposure causes suntan, sunburn and, in severe cases, blistering. UVB intensity fluctuates. UVB rays can be filtered and do not penetrate glass. UVA facts and risks. There is no such thing as a safe or healthy tan. UVA radiation is proven to contribute to the development of skin cancer.
Early sunscreens only protected your skin from UVB rays, but once it was understood how dangerous UVA rays were, sunscreen manufacturers began adding ingredients to protect you from both UVB and UVA across this broader spectrum. Exposure causes genetic damage to cells on the innermost part of your top layer of skin, where most skin cancers occur. The skin tries to prevent further damage by darkening, resulting in a tan.
Over time, UVA also leads to premature aging and skin cancer.
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