(RxWiki News) For years now, we’ve been told to wear sunscreen to protect our skin from the sun’s harmful rays. Sunscreen keeps you from getting sunburned. But does sunscreen really protect against skin cancer? The answer to that critical question is a resounding “yes!”
Scientists have shown in the laboratory that sunscreen blocked changes in skin cells that can lead to skin cancer and melanoma.
Moreover, sunscreen protected a gene — p53 — whose job it is to prevent cancer.
"Protect your skin when spending time in the sun."
Elke Hacker, PhD, a researcher in the AusSun Research Lab at Queensland University of Technology in Brisbane, Australia, and colleagues performed a series of lab tests to look at how ultraviolet (UV) rays change skin cells and the protective effects of sunscreen.
Skin cancer is the most common form of cancer in the US, affecting millions of Americans and people in other countries every year.
The three most common forms of the skin cancer are basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), which generally are not lethal, as well as melanoma, which can be deadly.
In melanoma, cells called melanocytes, which produce the skin’s pigment, are damaged and start to grow out of control. Exposure to the sun’s ultraviolet radiation plays a role in the development of this cancer that can spread throughout the body.
Scientists also know that a gene that fights off cancer development — called p53 — becomes damaged after repeated sun exposure, the authors of this study explained.
Dr. Hacker explained that the p53 gene repairs skin damage caused by the sun. However, after multiple sunburns, the p53 gene is weakened and can’t repair the sun-damaged skin, which in turn becomes more susceptible to cancer.
Previous research has found that a gene called MC1R, which is also involved in pigmentation, is strongly associated with melanoma risk, according to the authors.
For this experiment, the researchers gathered skin tissue samples (biopsies) from 57 individuals. The average age of participants was 28 years.
Two samples were exposed to ultraviolet light — one sample was protected by a broad-spectrum SPF (sun protection factor) 30+ sunscreen and the other had no sunscreen.
After 24 hours, the skin with sunscreen had no genetic changes, and there was no impact on the p53 gene.
The researchers also looked at how different skin cells responded to ultraviolet light and found that the number of melanocytes, the pigment cells involved in melanoma, nearly doubled after 14 days.
The gene MC1R played a key role in this proliferation, the researchers found.
The researchers also learned that sunscreen completely blocked the molecular changes and growth of keratinocytes — the most common type of skin cells — as well as melanocytes.
“This study confirms the role of ultraviolet radiation in initiating melanocytic proliferation, implicates MC1R as a key mediator in this process, and demonstrates the effectiveness of sunscreen in preventing these molecular responses," the study concluded.
The study was published in the September issue of Pigment Cell & Melanoma Research.
This work was funded by the Cancer Council Queensland and Atlantic Philanthropies.
No conflicts of interest were disclosed.