Study has shown bacteria which is commonly found on our skin acts as a potential “layer” of protection against cancer
The occurrence of skin cancer has been steadily increasing over the past decades. Skin cancer is of two kinds – melanoma and non-melanoma. The most common type is the melanoma skin cancer which causes 2 and 3 million cases globally every year. The non-melanoma is not the most common type and affects 130,000 globally but is also serious because it can spread. One in every three cancers diagnosed worldwide is a skin cancer. Our skin is the body’s largest organ and is also the most important as it covers the entire body and protects us from harmful external factors like sun, abnormal temperatures, germs, dust etc. The skin is responsible for controlling our body temperature and remove sweat from our body. It makes the essential vitamin D and marvellously, the skin provides us with a sense of touch. The main cause of skin cancer is overexposure to harmful rays of the sun. As the ozone layer in our atmosphere is gradually depleting the protective layer is going away leading to more UV (ultra-violet) radiation of the sun to reach the earth’s surface. Melanoma cancer, which starts in pigment-producing skin cells, is caused by abnormal changes in the skin when cancerous cells start growing and the main factor is somehow connected with an individual’s exposure to the sun and their history of sunburn. Non-melanoma skin cancer starts in the cells of the skin and grows out to destroy nearby tissue. This type of cancer generally does not spread to other parts of the body (metastasize) but melanoma cancer does.
A study published in Science Advances describes a new potential role of the bacteria on our skin in protecting us against cancer. Researchers at UC San Diego School of Medicine, USA have identified a strain of the bacteria Staphylococcus epidermidis which is very commonly found on healthy human skin. This unique strain of skin bacteria is seen to inhibit growth (kill) of several types of cancers by producing a chemical compound – 6-N-hydroxyaminopurine (6-HAP) in mice. It was clear that only the mice which had this bacterial strain on their skin and thus made 6-HAP did not have skin tumours after they were exposed to cancer causing UV rays. The chemical molecule 6-HAP basically impairs the synthesis (creation) of DNA thereby preventing the spread of tumour cells and also suppressing the development of new skin tumours. The mice were injected with 6-HAP every 48 hours over a period of two weeks. The strain is non-toxic and does not affect normal healthy cells while reducing the already present tumours by almost 50 percent. The authors state that the bacterial strain is adding “another layer” of protection to our skin against cancer.
This study clearly shows that our “skin microbiome” is an important aspect of the protection which skin offers. Some skin bacteria are already known for producing antimicrobial peptides which protect our skin from invasions by pathogenic bacteria. Further studies are required to understand the workings of 6-HAP and whether ideally it could be used as a preventative measure against cancer.
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Source(s)
Nakatsuji T et al. 2018. A commensal strain of Staphylococcus epidermidis protects against skin neoplasia. Science Advances. 4(2). https://doi.org/10.1126/sciadv.aao4502
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