Microorganisms Living on Your Skin May Relate to Skin Cancer Risk

animated rendering showing many microbes on blue background

Right now, there are billions of viruses, fungi, and bacteria living on your skin. They make up what is known as your skin microbiome. Don’t worry, though. No need to rush over to a sink and scrub them away. Most of these microorganisms are normal – and not harmful – regular residents of your body. 

In fact, many of these tiny organisms are extremely beneficial. They get along well with your body and play an important role in warding off infection and keeping you healthy. Together, these bugs make up what is called your skin microbiome.  

But sometimes things can get off balance. Researchers are starting to think that when your skin microbes are altered, they may contribute to health problems such as acne and other skin conditions.    

“The microbiome can interact with the immune system in a negative way,” explains Julia Oh, Ph.D., an Assistant Professor at the Jackson Laboratory for Genomic Medicine in Farmington, Conn. “This can cause different immune pathways to function improperly and result in disease.” 

While scientists have known about the microbiome in general for a long time, they have a lot more to learn when it comes to the specifics, such as how microbes might impact skin cancer development. 

Oh and her team think the skin microbiome may play a role in the development of a common skin cancer known as squamous cell carcinoma.

The number of cases of squamous cell carcinoma has been increasing for years, and about 1 million cases are diagnosed each year. Treatment of squamous cell carcinoma and other skin cancers is also a burden on the healthcare system – in the US, billions of dollars are spent to treat skin cancer each year, and costs continue to rise.

While the primary cause of this type of skin cancer is ultraviolet radiation (UV) from sun exposure or tanning beds, it often develops within the context of skin infection or chronic inflammation. Therefore, the skin microbiome might be linked to a person’s chances of developing squamous cell carcinoma, as well as influence how the cancer progresses and responds to treatment. If Oh and her team discover that the skin microbiome has a connection to squamous cell carcinoma, it could lead to the development of new treatments.

Oh says in recent months, she and the team have been focusing on creating a mouse model of UV-induced skin cancer that takes into account the skin microbiome.

“We thought that the microbes on the skin might be interacting with the damage that’s caused by UV radiation and, in turn, increasing skin cancer risk,” says Oh, whose work is being supported by a $792,000 grant from the American Cancer Society. “We are using mice that don’t have fur, so it resembles human skin, and we are testing how different microbes might change cancer risk and progression.” 

Since Oh is still in the first year of the 4-year project, the initial round of mouse experiments is still in progress. But as they continue to learn more, Oh and her team will build upon their mouse model to further investigate how the skin microbiome affects squamous cell carcinoma—for instance, if certain types of microbes can accelerate its development, perhaps selectively removing microbes from the skin will reduce cancer risk. 

Microbes could also potentially be manipulated to activate the immune system so it could attack and eliminate existing tumors. Oh says that increasing the number of beneficial or anti-inflammatory microbes in the skin – say, by using probiotics – is yet another method that could potentially be used to reduce squamous cell carcinoma risk or rate of progression. Oh hopes her research will inform the development of new therapies to treat squamous cell carcinoma or reduce the risk of this prevalent cancer type. 

 

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